HomeMy WebLinkAboutSP201800001 Study Water 2 2018-03-19WATER AND WASTEWATER
FACILITIES PLAN
2017 UPDATE
For
Ilk
p
----------
KEswICK HALL.
8z GOLF CLUB
December 1, 2017
Revised: March 19, 2018
Prepared by
TIMMONS GROUP .••'00
:••.
WATER AND WASTEWATER
FACILITIES PLAN
2017 UPDATE
For
KESWICK HALL
4& GOLF CLUB
QUALITY ASSURANCE
STATEMENT
A Quality Control and Assurance review has
been performed on this document in accord-
ance with the TIMMONS GROUP Quality
Plan. The undersigned states that this
document has been checked and reviewed in
a manner commensurate with the level of
WESLEY G. ((((�--�'
HUNNIUS
U Lie. No. 040151 ��
o
detail for the type of submittal indicated
below.
Wes Hunnaus
Senior Project Manager
3/Date
Dafe
Final
Type of Submittal
Prepared By:
Checked By:
Reviewed By:
BWS / MRM
BWS / MRM
WGH / DJS
December 1, 2017
Revised: March 19, 2018
Prepared by
•
TIMMONS GROUP .•
':'•.
TABLE OF CONTENTS
TABLE OF CONTENTS
The following chapters from the original Water and Wastewater Facilities Plan have been
updated to reflect the latest information obtained at the time this report was completed.
Please see the previous reports referenced in the appendices for the remaining chapters.
EXECUTIVE SUMMARY...............................................................................................................0-1
CHAPTER 1: INTRODUCTION — 2017 UPDATE
U1.1 Purpose.................................................................................................................1-1
U1.2 Scope....................................................................................................................1-1
U1.3 Source Information..............................................................................................1-2
CHAPTER 2: DEMANDS — 2017 UPDATE
U2.1 Existing Demands................................................................................................
2-1
Table U2-1: Existing Water Consumption
U2.2 Projected Demands..............................................................................................2-2
Table U2-2: Projected Water Consumption
CHAPTER 5: WATER FACILITIES PLAN — 2017 UPDATE
U5.1 General.................................................................................................................5-1
U5.2 Supply..................................................................................................................
5-1
U5.3 Storage.................................................................................................................
5-3
U5.4 Pumping...............................................................................................................
5-3
U5.5 Fire Protection......................................................................................................
5-5
U5.5.1 Internal Fire Protection
U5.5.2 External Fire Protection
U5.5.3 Retrofitting Existing System
U5.6 Irrigation.............................................................................................................
5-13
U5.7 Summary .............................................................................................................
5-13
U5.7.1 Water System Improvement Alternatives
U5.7.2 Conclusion
U5.8 Photos of Existing Water System.......................................................................5-18
CHAPTER 6: WASTEWATER FACILITIES PLAN — 2017 UPDATE
U6.1 Permit Modifications...........................................................................................
6-1
U6.2 Treatment Improvements.....................................................................................
6-2
Table U6-1: Projected Wastewater Flow
Table U6-2: Historical Wastewater Flows
Figure U6-1: Historical Wastewater Flows
Figure U6-2: Keswick STP Process Schematic
U6.3 Collection System................................................................................................
6-9
U6.4 Summary .............................................................................................................
6-10
U6.5 Photos of Existing STP.......................................................................................
6-12
TOC-I TIMMONS GROUP .••':••.
TABLE OF CONTENTS
APPENDICES
A: OPINION OF PROBABLE CONSTRUCTION COSTS
B: WATER AND WASTEWATER FACILITIES PLAN - NOVEMBER 3, 2000
C: WATER FACILITIES PLAN 2007 UPDATE - NOVEMBER 2, 2007
TOC-2 TIMMONS GROUP .••':••.
EXECUTIVE SUMMARY
EXECUTIVE SUMMARY
This Update was commissioned to determine Keswick's ultimate future water and
wastewater demands and the infrastructure improvements required to support those demands.
It is understood that a renovation and expansion project is planned for Keswick Hall & Golf
Club. The proposed construction phasing is as follows:
Phase IA: Pool Bar and Restrooms
Caf6/Retail Space
Villa Crawford Bar Addition
Spa Treatment Rooms
Reduced Key Count
Phase 113: Hotel Wing
Phase 2: Event Barn
Phase 3: Clubhouse Restaurant Expansion
Future: Subdivision Buildout
WATER SYSTEM
An immediate need of the renovation effort is establishing a new water source for fire
protection sprinkler systems at Keswick Hall & Golf Club. This would be accomplished by
installing a new 30,000 gallon ground storage tank, 500 GPM fire pump, and fire waterline
extending to each protected building. This dedicated internal fire suppression system is
referred to as Base Improvement WI: Dedicated Internal Fire Protection and the engineer's
opinion of probable construction cost (OPCC) is $696,000. If additional storage and flow are
required to accommodate the assumed hose stream allowance or ISO/IFC fire flows then
costs would increase to $746,000 or $775,000 respectively.
0-1 TIMMONS GROUP -• *' *%
EXECUTIVE SUMMARY
Based on existing water production and projected maximum daily demands, ultimate
buildout domestic water capacity requirements were calculated at 110,000 gallons per day
(GPD). The existing water distribution system is currently limited by effective storage
volume resulting in a permitted capacity of 76,000 GPD which is exceeded by the maximum
daily demands in Phase 2. Pumping capacity of the system is slightly higher at 78,000 GPD
which is exceeded by the maximum daily demands in Phase 2. Current well yield sets supply
capacity of the system at 80,480 GPD, which is exceeded by Phase 3. The current overall
permitted capacity of the existing water system is adequate to facilitate Phase IA and Phase
1B of the renovation and expansion plans. System upgrades are necessary to meet the
ultimate water demand. Virginia Department of Health Waterworks Regulations 12VAC5-
590-520 require community waterworks to commission design drawings, technical
specifications, and provide construction scheduling for water system expansion once
observed water production exceeds 80% of the current permitted capacity for 3 consecutive
months. This Update concludes maximum daily demands will exceed the existing 80%
threshold of permitted capacity upon completion of Phase IA, therefore design of the
domestic system expansion should begin simultaneously with the renovation efforts.
Future buildout domestic demands will require increasing the permitted water system
capacity to 110,000 GPD. This would be achieved by implementing Base Improvement W2:
Domestic System which includes one new well, an 18,000 gallon ground storage tank, and
two new 250 GPM booster pumps. The OPCC for Base Improvement W2 is $421,000.
Once Base Improvement W2 is complete and external fire protection is desired
throughout the subdivision in the future, Base Improvement W3: External Fire Protection
would need to be implemented. It consists of a 30,000 ground storage tank and a new 500
GPM fire pump inside of the existing well pump house. The OPCC for Base Improvement
W3 is $622,000.
If external fire protection throughout the subdivision is to be provided with the
domestic system expansion, then Alternate Improvement W4: Domestic + External Fire
Protection, Ground Storage would need to be implemented. Alternate Improvement W4
0-2 TIMMONS GROUP .•'':'%
EXECUTIVE SUMMARY
would be substituted for Base Improvement W2 and Base Improvement W3. It consists of a
combined 50,000 gallon ground storage tank in addition to the pumps listed in Base
Improvements W2 and W3. The OPCC for Alternate Improvement W4 is $825,000.
Alternate Improvement WS: Domestic + External Fire Protection, Elevated Storage
is consistent with the objectives of Alternate Improvement W4, minus the need for any pump
upgrades. It consists of an 100,000 gallon elevated tank and would allow for abandonment of
the existing non -pressurized ground storage tanks. The OPCC for Alternate Improvement W5
is $2,186,000.
The existing well -supplied water system relies on the high yielding Everona
Limestone geologic formation which passes through the easternmost tip of the Estate
property. An additional groundwater well will be required to meet the ultimate domestic
demands at buildout conditions. If an acceptable source of groundwater cannot be established
on the Keswick property, purchase of the adjacent property east of the well pump house may
be required for enhanced access to the Everona Limestone formation. The 2017 tax
assessment lists the assessed value of that parcel at $105,500.
WASTEWATER SYSTEM
The existing wastewater treatment system is a dual "train" 60,000 GPD facility with
sufficient permitted capacity to handle the Phase 1A, Phase 113, Phase 2, and Phase 3
renovation and expansion plans. A second tier of the discharge permit is already in place with
nutrient limits established for a permitted design capacity of 99,000 GPD. The addition of a
30,000 gallon equalization tank, a new 30,000 GPD train and the upgrade of the existing
facility's headworks and treatment components will increase capacity to 90,000 GPD,
allowing the facility to process projected average daily flows at buildout conditions. The
OPCC for wastewater treatment improvements is $1,859,000.
0-3 TIMMONS GROUP .••':••.
INTRODUCTION
CHAPTER 1
CHAPTER 1
INTRODUCTION - UPDATE
U1.1 PURPOSE
It has been over a decade since the completion of the last Water and Wastewater
Facilities Plan for Keswick Hall & Golf Club. Changes have continued to occur in the
existing and proposed water infrastructure, demands at Keswick Hall & Golf Club, and
demands in the surrounding subdivision since the preparation of the Water and Wastewater
Facilities Plan; prepared by Timmons Group in November 2000 and the subsequent Updates
completed in 2004, 2005, and 2007. As additional phases of development are currently being
planned, specific actions need to be made regarding the water and wastewater improvement
alternatives to be employed. This Update will evaluate capacities of the water and wastewater
systems and provide recommendations for upgrades to the facilities to meet the needs of the
proposed development.
U1.2 SCOPE
The scope of this Study is as follows:
• Re-evaluate existing and proposed demands and based on them, provide updated
estimates of future capacity requirements for the water and wastewater systems.
• Re-examine the existing water and wastewater systems to determine deficiencies,
if any, as related to their ability to meet the ultimate demands.
• Re-evaluate alternatives for upgrades to the existing water and wastewater
systems to meet projected ultimate demands, and make recommendations.
• Re-evaluate fire suppression alternatives to meet projected needs and make
recommendations.
1-1 TIMMONS GROUP
INTRODUCTION
CHAPTER 1
• Provide updated OPCC for the recommended upgrades and additions.
U 1.3 SOURCE INFORMATION
This Update was reliant upon data supplied by others. Sources include:
• Water consumption provided by Keswick Estates Utilities, Inc.
• Water well production provided by Environmental Systems Services, Ltd.
• Wastewater treatment flow provided by Environmental Systems Services, Ltd.
• Proposed renovation and expansion items provided by Hart Howerton, Ltd.
• Phasing of development provided by Hart Howerton, Ltd.
• Waterworks Permit provided by the Virginia Department of Health
• Virginia Pollutant Discharge Elimination System Permit provided by the Virginia
Department of Environmental Quality
• Existing sprinkler system flow requirements provided by 2RW Consultants, Inc.
• As -Built drawings of Water and Sewer Locations for Keswick Estates by
Roudabush, Gale & Associates, Inc., dated December 11, 2009.
• Previous Water and Wastewater Facilities Plans by Timmons Group, Inc.
While previous Facility Plans were based on water consumption data provided for
each water meter in the system, data provided for this Update included totalized monthly
water consumption for the entire system over the period analyzed. Individual meter readings
were requested, but not provided. As a result, water demand projections for categorical uses
were based on previous studies, Virginia Department of Health Waterworks Regulation
12VAC5-590-690, and sound engineering judgement.
1-2 TIMMONS GROUP
INTRODUCTION
CHAPTER 1
Proposed renovation and expansion plans provided were schematic in nature and
contained planning level information including number of hotel rooms, range of restaurant
seating capacity, range of overall square footage for proposed buildings, or general
descriptions of conceptual improvements. Assertions made from planning level information
should be interpreted as such. Recommendations provided in this study are for planning
purposes only and will need to be further evaluated during the design stage of procurement.
Existing water and wastewater system layouts are shown as schematic master plans
on the following pages.
1-3 TIMMONS GROUP
INTRODUCTION
CHAPTER 1
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INTRODUCTION
CHAPTER 1
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1-5 TIMMONS GROUP
DEMAND PROJECTIONS - UPDATE
CHAPTER 2
CHAPTER 2
DEMANDS — 2017 UPDATE
U2.1 EXISTING DEMANDS
For the January 2015 through July 2017 period analyzed, the average water billings
totaled approximately 958,830 gallons per month which increased approximately 102% from
the numbers used in the 2007 Update. As part of the 2017 Update, well production flows
were evaluated to determine that unmetered (and therefore unbilled) flow throughout the
distribution system was approximately 178,233 gallons per month. The total volume of
unmetered water accounted for 15% of the total water produced by the existing wells over
the period analyzed. Unmetered flow can represent a physical connection to the system
without a water meter or it could be a result of leakage from damaged or deteriorated pipes
and fittings.
Based on the new data compiled, the average daily demand is estimated at 37,351
gallons per day (GPD); a significant increase from the 17,467 GPD in the 2007 Update. This
increase can be attributed to increased consumption at existing connections, new single
family residences connected to the distribution network, and potential losses from aging
infrastructure. Existing water consumption is shown in Table U2-1.
Water system design requires that system capacity exceed the maximum daily
demand. The previous studies, utilizing available usage data, estimated maximum daily
demand as 160% of average daily demand. Peaking the observed average daily demand of
37,351 gallons by 160% results in a current maximum daily demand of approximately 59,800
GPD. Comparing the current observed water production rates for average day (37,351 GPD)
versus peak daily average (52,696 GPD), shows a 140% increase, therefore confirming a
peaking factor of 160% is reasonably conservative in determining maximum daily demand of
the Keswick water system. The calculated maximum daily demand of 59,800 GPD is the
baseline with which future demands are cumulated to project the required future capacity of
the waterworks.
2-1 TIMMONS GROUP
DEMAND PROJECTIONS - UPDATE
CHAPTER 2
Table U2-1: Existing Water Consumption
Water Consumption (Gallons)
Metered Flow
2015
2016
2017
Summary
10,934,907
12,201,941
6,638,938
29,775,786
Peak Month Demand
1,375,239
1,368,370
1,367,400
1,375,239
Peak Daily Average
44,363
44,141
44,110
44,204
Average Month
911,242
1,016,828
948,420
958,830
Average Day
29,959
33,430
31,316
31,568
Unmetered Flow
1,708,293
2,016,059
1,570,362
5,294,714
% of Well Production
14%
14%
19%
15%
Peak Month Demand
139,761
216,130
433,800
433,800
Peak Daily Average
4,508
6,972
13,994
8,491
Average Month
142,358
168,005
224,337
178,233
Average Day
4,611
5,434
7,305
5,783
Well Production
12,643,200
14,218,000
8,209,300
35,070,500
Peak Month
August
July
July
July 2017
Peak Month Demand
1,515,000
1,584,500
1,801,200
1,801,200
Peak Daily Average
48,871
51,113
58,103
52,696
Average Month
1,053,600
1,184,833
1,172,757
1,137,063
Average Day
34,569
38,864
38,621
37,351
Note: Water consumption data rom January 1, 2015 through July 31, 2017
U2.2 PROJECTED DEMANDS
In the previous Facility Plans, irrigation demands placed on the domestic system were
a substantial concern. The 2007 Update indicated that changes in irrigation policies and
practices were implemented to eliminate additional irrigation demands on the domestic
system. For the purposes of this study, it is assumed that similar irrigation restrictions are still
in place and will continue indefinitely. There are no provisions in the projected demands
herein to account for additional irrigation demands placed on the domestic system. Table U2-
2 summarizes the analysis of projected water consumption.
2-2 TIMMONS GROUP
DEMAND PROJECTIONS - UPDATE
CHAPTER 2
Table U2-2: Projected Water Consumption
Projected Maximum Daily Demand (Gallons)
Phase
Description
Count
Unit
Max Day
GPD
Notes
GPD/Unit
Average daily well production
Existing
Maximum Daily Demand
59,800
from 01/2015-07/2017 peaked
160%
POOL Bar and
VDH Waterworks Regulations
Restrooms
20
Seat
80
1,600
50 gpd average per restaurant
seat peaked 160%
VDH Waterworks Regulations
Cafe/Retail
600
S.F.
0.5
300
300 gpd average per 1,000 sq.
ft. of retail space peaked 160%
Villa Crawford
VDH Waterworks Regulations
Bar Addition
10
Seat
80
800
50 gpd average per restaurant
seat peaked 160%
Phase IA
Net Spa
2 treatments per room, 30
Treatment Rooms
4
Room
100
400
gallons per treatment, peaked
160%
Reduce Key
Average daily flow of 300 gpd
Count
-5
Key
300
-1,500
per unit during the peak month
as determined in the 2007 study
Phase lA Subtotal
1,600
Phase 1A Total Demand
61,400
Average daily flow of 300 gpd
Hotel Wing
43
Key
300
12,900
per unit during the peak month
Phase 113
as determined in the 2007 study
Phase 113 Subtotal
12,900
Phase 113 Total Demand
74,300
1 event per day, 200 people per
Event Barn
6,500
S.F.
0.7
4,800
event, 15 gallons per person,
Baked 160%
Phase 2
Phase 2 Subtotal
4,800
Phase 2 Total Demand
79,100
Clubhouse
VDH Waterworks Regulations
Restaurant
30
Seat
80
2,400
50 gpd average per restaurant
Phase 3
sion
seat peaked 160%
Phase 3 Subtotal
2,400
Phase 3 Total Demand
FSingle
81,500
Family
Average daily flow of 300 gpd
Residences
77
House
300
23,100
per unit during the peak month
Future
as determined in the 2007 study
Future Subtotal
23,100
Future Total Demand
104,600
Demand projections were evaluated based on unit values determined in previous
Facility Plans, analysis of historical water consumption, and the Virginia Department of
Health Waterworks Regulation 12VAC5-590-690. Existing maximum daily demand was
calculated in Section U2.1, Phases 1-3 are based on the proposed renovation and expansion
2-3 TIMMONS GROUP
DEMAND PROJECTIONS - UPDATE
CHAPTER 2
items, and the future demand is based on 77 remaining undeveloped lots. As shown in Table
U2-2, the future total maximum daily demand is approximately 104,600 gallons projected at
buildout; 110,000 gallons will be used as the maximum daily demand to determine design
capacities for future buildout conditions.
2-4 TIMMONS GROUP
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
CHAPTER 5
WATER FACILITIES PLAN - 2017 UPDATE
U5.1 GENERAL
As stated in the original Facility Plan and subsequent Updates, the buildout demands
of Keswick will require additional water system infrastructure. The Virginia Department of
Health (VDH) evaluates the permitted capacity of well -supplied community waterworks
based on the limiting of three factors: supply, storage, and pumping capacities. Each
parameter will be evaluated in the following sections with recommendations provided.
Additionally, the minimal level of fire protection currently provided throughout the
existing system merits discussion of related infrastructure improvements. This Update to
Chapter 5 addresses the items impacted by the new usage data and projected water
consumption. Where options are available, the implications, requirements, and critical cost
components of each are presented.
U5.2 SUPPLY
Water supply capacity is determined by the lowest of two well parameters: yield and
pumping capacity. The permittable capacity of well supplies in terms of daily demands is
governed by the VDH Waterworks Regulations. The VDH Regulation 12VAC5-590-690
requires 0.5 gallons per minute (GPM) of well yield for every equivalent residential
connection (ERC). An ERC is defined as 400 gallons per day (GPD). Essentially, one GPM
of well yield results in 800 GPD of available capacity. If the well yield (converted to
available capacity in GPD) is greater than the volume of water that the well pump could
generate in a 24 hour period, then the well pumping capacity becomes the governing criteria.
In the case of Keswick Utilities, the current combined well yield of 100.6 GPM limits the
permittable supply capacity to 80,480 GPD. Based on the proposed phasing of development,
the current well capacity could support Phase IA, Phase IB, and Phase 2.
5-1 TIMMONS GROUP -• *' *%
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
The existing supply of three wells with a permitted capacity of 80,480 GPD will not
be sufficient to meet the future maximum daily demand of 110,000 GPD. Based on the
current safe well yields, it is estimated that at least one additional well will need to be drilled
to raise the permitted capacity to meet projected future demands. The new well will need to
achieve a minimum safe well yield of 37 GPM which may only be accomplished if drilled in
the Everona Limestone formation.
There are two geologic formations located in the Keswick area. A majority of the
Keswick property is underlain by the Loudoun Formation, also known as the Candler
Formation, which does not contain prolific subsurface anomalies conducive to high
groundwater yields. The easternmost tip of the Estate is underlain by the Everona Limestone
formation; an approximately 3,000-foot wide band of heavily fractured bedrock having
exceptional hydrogeologic characteristics that traverses the region from southwest to
northeast. More information on the regional geology and water bearing features can be found
in the original Water and Wastewater Facility Plan from 2000.
Preliminary discussions have occurred in the past between Keswick and
Environmental Systems Services (ESS) planning a new well in the area immediately
surrounding the existing pump house near Route 616. The discussions included drilling a
test well near the pump house to determine a yield and evaluate potential impacts on the
existing wells however, no specific action has been taken regarding its construction. This
approach is recommended for the new well required.
Based on current demand projections, if the new well is constructed and found to be
of sufficient capacity, expansion of the well field east of the Estate's property would not be
required as stated in previous Facility Plans. However, if Keswick Utilities wishes to secure
future additional water sources or if groundwater investigations determine that the well
production needed cannot be achieved within the available drilling locations, acquisition of
the adjacent property, currently owned by Michael Atkins c/o Wendell Wood, is
recommended since evidence suggests the Everona Limestone formation underlies the
adjacent property. However, further subsurface analysis, including test drilling and pump
5-2 TIMMONS GROUP .••':••.
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
testing would be required to confirm this. The current tax records list the 2017 assessed value
of the 16.26 acre parcel at $105,500.
U5.3 STORAGE
Based on the VDH Waterworks Regulations, storage must be equivalent to 50% of
design capacity. Conversely, the permittable capacity of the system is equal to twice the
effective storage capacity. The two existing ground storage tanks plus the existing
hydropneumatic tank have a total effective storage capacity of 38,000 gallons making the
current permitted system capacity 76,000 GPD. Therefore, storage is the current limiting
factor of the entire water system. Based on the proposed phasing of development, the current
storage capacity could only support Phase IA and Phase 113. Additional infrastructure
improvements will be required to implement Phase 2.
For the updated 110,000 GPD maximum daily demand, a minimum of approximately
55,000 gallons of effective storage must be provided. To meet these requirements, 17,000
gallons of effective storage must be added to the system. It is recommended that a new
18,000 gallon non -pressurized ground storage tank be added to the system adjacent to the
two existing 18,000 gallon ground storage tanks.
U5.4 PUMPING
Based on the VDH Waterworks Regulations, required pumping capacity (from non -
pressurized storage into the distribution system) is based on the formula:
Pump Rate = (11.4) (Design Capacity / 400) os44
Using the existing booster pump rate of 200 GPM and solving for design capacity gives a
permittable capacity of 78,000 GPD. Based on the proposed phasing of development, the
current booster pump capacity could support Phase IA and Phase 113.
5-3 TIMMONS GROUP -• *' *%
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
The existing booster pumps with a permitted capacity of 78,000 GPD will not be
adequate to meet the future maximum daily demand of 110,000 GPD. Using the same
formula above, inserting the future maximum daily demand as the design capacity and
solving for pump rate results in 242 GPM. This exceeds the current pumping capacity of the
system by 42 GPM.
According to VDH Waterworks Regulations, if two pumping units are provided then
each unit must be capable of supplying the peak demand and if more than two pumping units
are provided, they shall have sufficient capacity so that any combination of two pumps are
capable of carrying the peak demand. The existing pump house appears to have enough space
for a third pump so that affords multiple options for improving pumping capacity. The
addition of a third booster pump with a pumping capacity of 42 GPM would be the minimum
improvement required by the regulations. However, if one of the existing pumps were to be
taken out of service for an extended period then the two remaining pumps would not achieve
the required capacity. For that reason, it would be recommended that the third pump have a
nominal 250 GPM capacity to independently handle the peak demand. Alternatively, the
preferred option is to replace the two existing booster pumps with higher capacity pumps that
will supply 250 GPM each. That results in fewer piping changes, less mechanical equipment
to maintain, standardized repair work, allows space for future expansion, and potentially
reduces generator capacity required to run two pumps instead of three. Selecting the three
pump option could save capital initially by only purchasing one new pump, but it is worth
noting that the existing booster pumps are approximately 13 years old and pumping systems
have a typical lifespan of 15-20 years.
In some cases, existing pumps can be upgraded with larger motors or impellers to
increase their capacity. That approach was evaluated, but the existing pumps already have the
largest motor and impeller combination available for that particular model according to the
manufacturer's published literature.
One ancillary effect of increasing pumping capacity is the electrical upgrades that
may be required. Adding or replacing pumps could impact the existing pump controls, wires,
5-4 TIMMONS GROUP --`*%
WATER FACILITIES PLAN - UPDATE CHAPTER 5
circuit breakers, transfer switches, and generators. The full extent of electrical upgrades for
each option presented in this Update would require further evaluation by an electrical
engineer during the design phase of procurement.
U5.5 FIRE PROTECTION
Two distinctly different types of fire protection will be discussed in this section:
internal and external. Internal fire protection refers to existing and proposed building
sprinkler systems whereas external fire protection refers to existing fire hydrants throughout
the distribution system.
U5.5.1 INTERNAL FIRE PROTECTION
V VTQ-PTT.Tr,
The existing Keswick Hall and Golf Club currently have internal fire protection in the
form of wet and dry pipe sprinkler systems. Sprinkler flow is delivered to both buildings by a
fire pump that draws water from an existing swimming pool. The pool was originally
disinfected with traditional chlorine then at some point was converted to a salt water chlorine
generator. Both disinfection methods result in free ions that can accelerate corrosion of
metallic elements exposed to the disinfected water. Assessment of the existing sprinkler
system at Keswick Hall and Golf Club by others has determined that pipe replacement is
recommended as part of the renovation efforts. A supplemental recommendation is to
abandon the sprinkler system connection to the pool and establish a new water source for
internal fire protection.
It is estimated by others that the existing sprinkler system requires 487.8 GPM for a
duration of 60 minutes. The total required storage volume of water for internal fire protection
would then be approximately 29,268 gallons. The existing maximum daily demands of the
system are approximately 59,800 GPD which requires a storage volume of 29,900 gallons.
With a current total effective storage volume of 38,000 gallons, the existing system does not
5-5 TIMMONS GROUP --`*%
WATER FACILITIES PLAN - UPDATE CHAPTER 5
have adequate capacity to serve the maximum daily demands plus maintain water reserves
for internal fire protection.
Aside from storage, another limiting factor for internal fire protection is water
delivery to the system. The existing booster pumps that supply the distribution system are
only rated for 200 GPM each, whereas the existing fire pump requires 487.8 GPM. This
shortfall would prevent the fire pump from directly connecting to the existing distribution
system.
PROPOSED
The recommended solution is to provide water infrastructure dedicated to internal fire
protection of the existing Keswick Hall & Golf Club and the surrounding buildings that will
have sprinkler systems. Assuming the worst case sprinkler flow for a protected area is 500
GPM for a duration of 60 minutes, the system would consist of a nominal 30,000 gallon non -
pressurized ground storage tank near Keswick Hall and a fire pump located in an adjacent
building capable of delivering 500 GPM at the discharge pressure required to operate the
sprinkler heads. The existing fire pump would need to be removed due to proposed changes
in the water supply location, elevation, and piping configuration. A minimum 8" dedicated
fire waterline will need to be installed from the new fire pump discharge to each building
equipped with a sprinkler system. However, larger diameter pipe could be installed to reduce
friction losses, decreasing the energy required by the new fire pump. This dedicated internal
fire protection system consisting of a ground storage tank, fire pump, and fire waterline
would avoid the need to install individual fire pumps in every building with a sprinkler
system.
Another potential option would involve upgrading the domestic system to
accommodate connection of the internal fire protection system(s). The required 30,000
gallons of fire storage would be combined with the additional 18,000 gallons of storage
slated for domestic use in a non -pressurized ground storage tank near the well pump house. A
third booster pump with a capacity of 500 GPM would be added to the two upgraded 250
GPM booster pumps. It is understood that the goal is to provide internal fire protection
5-6 TIMMONS GROUP -• *' *%
WATER FACILITIES PLAN - UPDATE CHAPTER 5
upgrades as part of the immediate renovation efforts. Providing a combined domestic and
internal fire protection system would be subject to VDH Office of Drinking Water permitting
and potentially the Albemarle County Special Use Permit Review process which does not fit
into the proposed renovation schedule. This combined domestic and internal fire protection
supply configuration was evaluated as part of this Update, but determined unfeasible due to
the lead time required to obtain approvals.
ADDITIONAL PROVISIONS
As previously stated, the dedicated fire protection system with a 30,000 gallon fire
storage volume is based on an assumed 500 GPM sprinkler flow for a duration of 60 minutes.
This calculation does not account for a hose stream allowance which could be a provision of
the MEP Engineer's determination of fire protection demands. If we assume a sprinkler flow
of 500 GPM plus a hose stream flow of 500 GPM, the total fire protection demand is 1,000
GPM for 60 minutes, requiring an effective fire storage volume of 60,000 gallons and a fire
pump capable of generating 1,000 GPM at system specific discharge head conditions. Even
still, the Insurance Services Office (ISO) determination of Needed Fire Flow or the
International Fire Code (IFC) calculation of Fire -Flow Requirements for Buildings as
determined by the MEP Engineer may not be fully met until an additional 1,000 GPM or
more is provided. Assuming a sprinkler flow of 500 GPM plus an ISO or IFC fire flow
demand of 1,000 GPM, the total fire protection demand is 1,500 GPM for 60 minutes,
requiring an effective fire storage volume of 90,000 gallons and a fire pump capable of
generating 1,500 GPM at the system specific discharge head conditions. It is common to see
ISO or IFC fire flows alone reach 1,000-2,500 GPM or greater depending on a building's
construction, area, occupancy, and exposure. The total fire flow demand for each protected
building will be determined by the MEP Engineer from the architectural design plans. The
dedicated fire storage tank volume and fire pump capacity will be sized based on an
evaluation of each total fire flow demand provided by the MEP Engineer for the protected
buildings.
5-7 TIMMONS GROUP .••':••.
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
U5.5.2 EXTERNAL FIRE PROTECTION
Previous Facility Plans have discussed the many benefits of providing external fire
protection throughout the subdivision. Fire hydrants were installed with the most recent 8"
waterline construction in Section IX along Keswick Lane and Palmer Lane in anticipation of
additional system improvements to allow for external fire protection. According to VDH
Waterworks Regulation 12VAC5-590-690, applicable fire flows shall be selected by
coordination between the water supply owner, design consultant, local officials, and the local
fire marshal in the authority having jurisdiction. Given that Keswick Utilities operates a
rural, well -based system comprised of mostly 6" and some 8" diameter waterlines, it is
assumed that the required fire flow will be 500 GPM for a duration of 60 minutes, but the
local officials and fire marshal should be engaged during design to confirm this requirement.
If a greater external fire flow rate is required by the authority having jurisdiction, a
substantial linear footage of waterlines throughout the distribution system would need to be
upsized to prevent excessive system pressures.
An additional storage volume of 30,000 gallons will be required for external fire
protection based on the stated assumption of 500 GPM for a duration of 60 minutes. Because
fire hydrants are connected to the domestic distribution system, the storage volume for
external fire protection would be combined with the required domestic storage of 55,000
gallons. That brings the total minimum effective storage volume of the system to 85,000
gallons which exceeds the current effective storage volume by 47,000 gallons.
GROUND STORAGE & PUMPING
There are several water system configurations that could be implemented to achieve
external fire protection. As presented earlier for internal fire protection, ground storage
tank(s) with two domestic booster pumps and a high service fire booster pump is also an
option for external fire protection. The third booster pump in this scenario would need a
capacity of 500 GPM at system specific discharge head conditions. It is assumed that there is
adequate space within the existing pump house to accommodate a third pump. The higher
capacity booster pump will likely require a generator upgrade for backup power at the pump
5-8 TIMMONS GROUP -• *' *%
WATER FACILITIES PLAN - UPDATE CHAPTER 5
house. The increased flow and pressure output required for the 500 GPM pump will require
higher initial capital and ongoing operational costs, but the recurring operational costs would
not be fully realized because it is assumed that the pump's full capacity would be
infrequently utilized.
The recommended location for new ground storage tank(s) for domestic and external
fire protection demands is near the existing pump house. It is possible, although not
recommended, to locate new ground storage and pumping equipment elsewhere in the
system. This Update specifically evaluated locations in the northern portion of the Estate near
Keswick Hall where the elevations are higher. Establishing a new tank location away from
the existing pump house would require a new building adjacent to the tank to house pumping
equipment and controls. The two existing booster pumps would need to remain in service at
the existing pump house to deliver source water to the system for refilling the new tank;
increasing operational costs and maintenance requirements associated with additional pumps.
A SCADA (Supervisory Control and Data Acquisition) system would also need to be
implemented so monitoring and control signals could be communicated between distant
water infrastructure components.
Water quality also becomes a concern when the water source and storage are on
opposite ends of the distribution network. It is challenging to cycle enough water through the
remote tank to maintain the required disinfectant residual without producing undesirable
disinfection byproducts. A chlorine monitoring system would be recommended for any
remote tank or for any system configuration with a total storage volume that far exceeds the
minimum effective storage required to satisfy the maximum daily domestic demands. The
same constraints apply when recommending a mixing system inside of a storage tank. Active
or passive mixers are installed to prevent potable water from stratifying into layers of
fluctuating water quality. Many utility owners will also implement flushing programs that
consist of opening one or more hydrants at the extents of the distribution system to discharge
any older, stagnant water and circulate better quality water in its place.
5-9 TIMMONS GROUP -• *' *%
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
Consideration should be given to the size and number of new tanks for scenarios that
include combined domestic and fire protection storage. Ground storage tanks come in
varying sizes with incremental standard volumes available over the range of storage options
evaluated for Keswick. It is not required, but could be advantageous to allocate the required
storage volume between two or more ground storage tanks for redundancy within the
distribution system. If one tank needs to be taken out of service for maintenance then it
would not compromise the entire system operation, otherwise temporary storage may need to
be established during maintenance procedures. Maintenance intervals vary between tank
style, material, use, and potentially at the discretion of the governing VDH Office of
Drinking Water.
Depending on the condition of existing storage tanks currently in service at Keswick,
they could potentially remain active or get decommissioned as part of the system
improvements. At least one of the existing ground storage tanks was recently taken out of
service for cleaning and rehabilitation. A professional inspection and condition assessment of
each existing storage tank is recommended to determine the viability of its continued use.
ELEVATED STORAGE
An elevated storage tank is another option for storage capacities provided for external
fire protection, depending on the height required to pressurize the system. This structure
would ideally be located near the existing pump house so water from the wells would be
disinfected, pumped into the elevated tank and then distributed to the system. Booster pumps
would remain in the pump house, but only for the purpose of filling the tank. Their capacity
would need to be approximately equal to the permittable safe well yield, which is a lower
flow rate compared to the minimum required booster pumping capacity, reducing operational
costs. The property adjacent to the pump house, previously identified for its access to the
Everona Limestone formation, also has an area of land with elevations approximately 40 feet
higher than the pump house itself. Constructing a tank at that location would reduce the
required tank height, in turn reducing construction and future maintenance costs.
5-10 TIMMONS GROUP .•'':'%
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
It is possible to locate the elevated tank elsewhere in the system, but not
recommended. This Update specifically evaluated locations in the northern portion of the
Estate near Keswick Hall where the elevations are higher. It would then become more
challenging to cycle through the volume of water in a tank that is "floating" on the system;
meaning that the tank provides flow and pressure to the system, but also relies on system
flow and pressure to replenish its volume. Water quality deteriorates proportionately with
water age so again, disinfection monitoring, mixing systems, and a regimented flushing
program would be recommended. An elevated tank has the benefit of requiring significantly
less pumping equipment than systems comprised of ground storage and booster pumps.
Elevated storage provides consistently reliable flow and pressure to the distribution network
even when power is lost.
U5.5.3 RETROFITTING EXISTING SYSTEM
To maximize the effectiveness of the new external fire protection capabilities, fire
hydrants will need to be retrofitted to the existing water system in the existing developed
areas of Keswick. According to the Albemarle County Service Authority Regulations,
generally, fire hydrants shall be placed no closer than 40 feet nor further away than 400 feet
from all major structures and no fire hydrant shall be more than 800 feet from any other
hydrant measured along the centerline of the road. Per these requirements, the schematic
shown on the following page has been prepared to demonstrate the approximate location of
the existing fire hydrants (in blue) and where new fire hydrants should be retrofitted to the
existing system (in red). The locations shown are approximate and should be field verified
during design.
5-11 TIMMONS GROUP --`*%
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
�aII
1 3tn�
g 33 8ys,C� S�y� iypip @' � �1 �•
5-12 TIMMONS GROUP .••':••.
WATER FACILITIES PLAN - UPDATE CHAPTER 5
U5.6 IRRIGATION
The original Water and Wastewater Facility Plan completed in 2000 identified
irrigation demands as the controlling factor of system capacity. The plan Update completed
in 2007 acknowledged that switching the golf course irrigation from the domestic system to a
pond supplied system and curtailing residential irrigation considerably reduced the projected
storage requirements. Residential irrigation provisions were not explicitly requested as an
objective of this Update, but while evaluating options for system improvements, a summary
of available alternatives would not be complete without addressing the concept of residential
irrigation. It is recommended that residential irrigation remain a prohibited use of the potable
water supply.
Groundwater is a valuable natural resource that is subject to seasonal fluctuations in
recharge and everchanging aquifer dynamics. The previous Facility Plan calculated
residential irrigation demands at approximately 120,000 GPD. Placing that additional
demand on the groundwater supply could have negative local affects on aquifer quality and
performance, which is a risk that is not recommended considering Keswick Hall and Golf
Club and the surrounding subdivision are dependent on the aquifer for potable water.
U5.7 SUMMARY
According to the VDH Waterworks Regulation 12VAC5-590-520, once the water
production of a community waterworks such as Keswick reaches 80% of the rated capacity
of the waterworks for any consecutive three-month period, the owner shall cause plans and
specification to be developed for expansion of the waterworks to include a schedule for
construction. The current permitted capacity of the existing water system is 76,000 GPD,
setting the 80% threshold at 60,800 GPD. There are no known capacity violations to date,
however for example, July 2017 saw an average water production of 58,103 GPD. It appears
inevitable that water production will exceed the current 80% capacity threshold of the
existing system as development occurs. An analysis of the projected demands in section U2.2
5-13 TIMMONS GROUP -• *' *%
WATER FACILITIES PLAN - UPDATE CHAPTER 5
shows the maximum daily demand exceeding the current 80% capacity threshold with the
implementation of Phase IA. It is recommended to commission a water system design
simultaneously with the renovation efforts to remain in compliance with state regulations.
There are a variety of infrastructure combinations that would meet Keswick's current
needs. A supply alternative must be selected to meet the immediate need for internal fire
protection. A supply alternative must also be selected to meet the ultimate domestic
demands. Additional infrastructure would need to be added to the system to provide external
fire protection capabilities throughout the subdivision. If external fire protection is a high
priority, then the economical choice would be to upgrade the system to accommodate
domestic demands and external fire protection demands with a single project. Consideration
should be given to the planned renovation and expansion schedule, budget constraints, and
enduring vision of the Estate.
A list of recommended water system improvements is presented below with key
directives. A more detailed list of critical project components and the engineer's opinion of
probable construction costs (OPCC) for each are provided in Appendix A. Each alternative is
based in large part on assumptions made from planning level details of proposed renovation
and expansion activities. Reasonable assumptions were made as to the project intent based on
the evaluated information provided. Furthermore, reasonable assumptions were made as to
how the authorities having jurisdiction will interpret and apply regulations, codes,
ordinances, etc., but the actual project requirements determined during design by the
authorities having jurisdiction may vary from the assumptions presented herein. The
engineer's OPCC is based on best judgment, experience, and being qualified professionals
generally familiar with the construction industry. Because the engineer has no control over
the cost of labor, materials, equipment, services furnished by others, or over competitive
bidding or market conditions, the engineer cannot guarantee that actual construction costs
will not vary from the OPCC presented. The OPCC provided do not include costs for
financing, property, or easement acquisition services. The following OPCC are presented in
2017 dollars and costs should be adjusted in subsequent years.
5-14 TIMMONS GROUP --`*%
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
U5.7.1 WATER SYSTEM IMPROVEMENT ALTERNATIVES
Base Improvement WI: Dedicated Internal Fire Protection
- Implement immediately
Add 500 GPMHose Stream Flow for 60 minutes
OR
Add 1, 000 GPM ISO/IFC Fire Flow for 60 minutes
Base Improvement W2: Domestic System
- Design during renovation, construct as part of Phase 2 expansion
Base Improvement W3: External Fire Protection (EFP)
- Future upgrade upon completion of Base Improvement W2
Alternate Improvement W4: Domestic + EFP, Ground Storage
- Replaces Base Improvements W2 and W3
- Adheres to Base Improvement W2 implementation schedule
- Not to be combined with Alternate Improvement W5
Alternate Improvement W5: Domestic + EFP, Elevated Storage
- Replaces Base Improvements W2 and W3
- Not to be combined with Alternate Improvement W4
Refer to the detailed OPCC in Appendix A.
$696,000
+$50, 000
+$79, 000
$421,000
$622, 000
$825,000
$2,186, 000
5-15 TIMMONS GROUP .••':••.
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
U5.7.2 CONCLUSION
In accordance with the proposed phasing and the project schedule, Base Improvement
WI: Dedicated Internal Fire Protection should be implemented immediately in preparation
for the renovation and expansion work.
According to the projected demands and proposed phasing of renovation and
expansion plans, the current permitted capacity of the existing water distribution system is
adequate to support Phase IA and Phase 113. The minimum required upgrades to meet the
future maximum daily domestic demands at buildout conditions are contained in Base
Improvement W2: Domestic System. This Update recommends executing Base Improvement
W2 in conjunction with the Phase 2 expansion.
Base Improvement W3: External Fire Protection represents the OPCC in 2017 dollars
to add provisions to the distribution system in the future (after the Base Improvement W2
upgrades are complete) to accommodate the assumed external fire protection demand.
External fire protection capabilities are not currently provided by the existing distribution
system, but previous infrastructure projects have already made improvements to the system
in anticipation of providing external fire protection. A cost benefit could be realized by
replacing Base Improvement W2 and Base Improvement W3 with a single project.
Alternate Improvement W4: Ground Storage or Alternate Improvement W5: Elevated
Storage could take the place of Base Improvement W2 and Base Improvement W3 if priority
is given to providing external fire protection throughout the subdivision at the same time
upgrades are going to occur to increase domestic capacity. This would achieve the vision of
encompassing the entire subdivision with a higher level of water service and improved life
and property safety with capacity to meet future buildout domestic demands and assumed
external fire protection demands. Alternate Improvement W4 would be recommended over
Alternate Improvement W5 for its lower capital cost and shorter construction time, although
operational costs would be higher and maintenance would be more intensive.
5-16 TIMMONS GROUP .••':••.
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
The types and magnitude of future water demands at Keswick will require additional
supply, storage, and pumping capacities and waterline upgrades. Base Improvement WI must
be implemented immediately, Base Improvement W2 must be implemented in conjunction
with Phase 2. It is recommended to implement Base Improvement W3 as soon as feasibly
possible. Alternate Improvement W4 or Alternate Improvement W5 would replace Base
Improvement W2 and Base Improvement W3. The external fire protection alternative selected
will need to consider construction sequencing, capital costs, operation and maintenance costs,
and reliability. As the proposed renovation and expansion project progresses with each phase,
the recommendations given in this report should be revisited to confirm adherence with the
design being commissioned and revised to suit evolving project needs.
5-17 TIMMONS GROUP .•'':'%
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
U5.8 PHOTOS OF EXISTING WATER SYSTEM
Photo W 1 — Well Pump House and Ground Storage Tank.
Photo W2 — Well Meters.
5-18 TIMMONS GROUP
WATER FACILITIES PLAN - UPDATE CHAPTER 5
Photo W3 — Pump House Interior.
Photo W4 — Booster Pumps.
5-19 TIMMONS GROUP .••':••.
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
Photo W5 — Hydropneumatic Tank.
5-20 TIMMONS GROUP .•,':'%
WASTEWATER FACILITY PLAN
CHAPTER 6
CHAPTER 6
WASTEWATER FACILITIES PLAN - 2017 UPDATE
U6.1 PERMIT MODIFICATIONS
The buildout demands of Keswick will require additional wastewater system
infrastructure. The infrastructure can be divided into two portions, the collection and
conveyance of the raw wastewater, and the treatment and discharge of wastewater.
The National Pollutant Discharge Elimination System (NPDES) Permit Program
regulates point sources that discharge pollutants to waters of the United States. Virginia
Department of Environmental Quality (VDEQ) is authorized to enforce and regulate the
program for Virginia. VDEQ's Sewage Collection and Treatment (SCAT) regulations
establish discharge limits and conditions for discharge for each point source. The Keswick
Sewage Treatment Plant (STP) is regulated under permit number VA0085979 and was last
reissued on March 1, 2016. As permits must be reissued every five years, the current permit
will expire February 28, 2021.
Keswick STP has two permitted outfalls, 001 and 004. Outfall 001 discharges to
Carroll Creek, which is tributary to the James (Middle) River Basin. Outfall 004 discharges
to the lower end of Broadmoor Lake, which has been used for onsite irrigation of the golf
course. Water for golf course irrigation is withdrawn downstream of Outfall 004 from
Paradise Lake. Any upgrades to the wastewater infrastructure discussed herein do not
consider discharge to Outfall 004. Additional treatment upgrades to the Keswick STP may
be necessary to meet permit limits for water reuse. Evaluation of those requirements falls
outside the scope of this analysis.
Keswick STP has a two -tiered flow permit. The design flow for the current STP is
permitted at 0.060 million gallons per day (MGD), or 60,000 gallons per day (gpd). When
necessary, the higher permitted tier has a design flow of 0.099 MGD, or 99,000 gpd. The
STP is currently operating under the limits set forth for the lower, 0.060 MGD, flow tier.
6-1 TIMMONS GROUP
WASTEWATER FACILITY PLAN CHAPTER 6
The higher flow tier limits will be triggered when the 95% capacity reopener is reached. The
95% capacity reopener states that when the monthly average influent flow to the wastewater
treatment facility reaches 95 percent of the design capacity authorized in the permit for each
month of any three consecutive month period then a written notice and plan of action for
ensuring continued compliance with the permit must be submitted to VDEQ. So when the
influent flow to the STP has a monthly average daily flow of at least 57,000 gpd for three
consecutive months, this 95% capacity reopener would apply.
The higher flow tier permitted discharge limits are similar to the current discharge
limits with the exception of nitrogen and phosphorus. The 60,000 gpd effluent limits do not
set a limit for total nitrogen or total phosphorus. The 99,000 gpd effluent limits for total
nitrogen are 8.0 mg/L and are 1.0 mg/L for total phosphorus, both on a monthly average.
The addition of these nutrient limits will affect the treatment methods for the Keswick STP
as discussed in Section U6.2.
U6.2 TREATMENT IMPROVEMENTS
As development will continue to occur at Keswick, it is expected the higher flow tier
will be required in the future. To continue to meet the effluent limits at the higher expected
flows, several upgrades and modifications to the Keswick STP are proposed. First, a
determination of the expected buildout wastewater flows must be estimated. Wastewater
treatment capacity is typically selected to meet average demands, as permitting and effluent
requirements are primarily based on monthly averages. Table U6-1 presents the projected
wastewater flows on an average daily basis. The existing average daily demand is based on
the new data compiled and presented in Section U2.1. The flow factors (gpd/unit) used are
based on Table 3 of SCAT 9VAC25-790-460. This table and section of the SCAT describes
the contributing flow estimates to be used as a design basis. The buildout projected average
daily flow is 69,431 gpd. Applying a 30% safety factor to the design, the Keswick STP
should be upgraded to a 90,000 gpd facility at buildout.
6-2 TIMMONS GROUP
WASTEWATER FACILITY PLAN
CHAPTER 6
Table U6-1: Projected Wastewater Flow
Projected Average Daily Flow (Gallons)
Average
Phase
Description
Count
Unit
GPD
Notes
GPD/Unit
Existing
Average Daily Demand
37,351
Average daily well production
from 01/2015-07/2017
POOL Bar and
20
seat
50
1,000
SCAT Regulations 50 gpd
Restrooms
average per restaurant seat
SCAT Regulations 300 gpd
Cafe/Retail
600
S.F.
0.3
180
average per 1,000 sq. ft. of
retails ace
Villa Crawford
10
Seat
50
500
SCAT Regulations 50 gpd
Bar Addition
average per restaurant seat
Phase 'A
Net Spa Treatment
4
Room
60
240
2 treatments per room, 30
Rooms
gallons per treatment
Reduce Key
Average daily flow of 270 gpd
Count
-5
Key
270
-1,350
per unit as determined in the
2007 stud
Phase lA Subtotal
570
Phase 1A Total Demand
37,921
Average daily flow of 270 gpd
Hotel Wing
43
Key
270
11,610
per unit as determined in the
2007 stud
Phase 113
Phase 1B Subtotal
11,610
Phase 1B Total Demand
49,531
Event Barn
6,500
S.F.
0.5
3,000
1 event per day, 200 people per
event, 15 gallons per person
Phase 2
Phase 2 Subtotal
3,000
Phase 2 Total Demand
52,531
Clubhouse
Restaurant
30
Seat
50
1,500
SCAT Regulations 50 gpd
Phase 3
Ex anion
average per restaurant seat
Phase 3 Subtotal
1,500
Phase 3 Total Demand
54,031
Single Family
Average daily flow of 200 gpd
Residences
77
House
200
15,400
per unit as determined in the
2007 stud
Future
Future Subtotal
15,400
Future Total Demand
69,431
As the 95% capacity reopener for the 99,000 gpd permit tier is 94,050 gpd, the permit
is adequate for the projected buildout wastewater flows. If changes are made to the Keswick
facilities plan and buildout flows increase beyond 99,000 gpd, modifications to the permit
would have to be pursued through VDEQ. This would necessitate a permit with a design
flow greater than 0.1 MGD, which may trigger additional operational and/or monitoring
6-3 TIMMONS GROUP
WASTEWATER FACILITY PLAN CHAPTER 6
requirements, and therefore potentially increase operating costs. For example, for permits
with design flows greater than 0.1 MGD and using advanced waste treatment methods,
VDEQ SCAT 9VAC25-790-300 recommends the plant to be manned 16 hours each day, as
opposed to 8 hours each day for equivalent plants with design flow less than 0.1 MGD.
It is also understood that the roof drainage for some of the buildings onsite are
directly tied to the sanitary collection system. Elimination of these direct inflow connections
will decrease flows to the STP. Additionally, should it be necessary, an infiltration study
may be pursued to determine if any aging infrastructure in the collection system is allowing
groundwater to infiltrate into the pipes. Identification and rehabilitation of these segments of
pipes would also reduce flows to the STP.
The Wastewater Facilities Plan performed by Timmons in 2000 concluded that while
the exact effluent limits were not yet known at the time, the existing treatment process would
be capable of achieving the new effluent limits. However, on December 29, 2010, the U.S.
Environmental Protection Agency established the Chesapeake Bay Total Maximum Daily
Load (TMDL). The TMDL is a historic and comprehensive "pollution diet" to restore clean
water in the Chesapeake Bay and the region's streams, creeks, and rivers. This regulation
affected the permit limits for Keswick STP as it is located within the Chesapeake Bay
watershed. Therefore, more advanced treatment upgrades will be required than were
recommended in the 2000 Plan.
While the treatment upgrades are recommended based on an average daily flow,
Keswick experiences a significant seasonality of water use due to Inn operations. Their
average daily demands during summer peak months are higher than the non -peak month
average daily demands. However, as presented in Table U6.2 and Figure U6.1, these
summer peak month demands have not been reflected in the wastewater flows over the past
two and one-half years of operation (30 months). Therefore, using average daily flows to
size and design STP upgrades is a reasonably conservative basis.
Additionally, section 9VAC25-790-830 of SCAT states:
6-4 TIMMONS GROUP
WASTEWATER FACILITY PLAN
CHAPTER 6
"Flow equalization shall be provided upstream of biological treatment works
designed to process a mean daily flow of 0.1 mgd or less that are permitted with ... a total
phosphorus of less than 2 mg/l. "
As the proposed plant would fall under this category, a flow equalization basin for the
STP is recommended. The EQ basin would be sized for one-third of the design flow, or
30,000 gallons. Within the treatment train, the tank would be placed after the headworks, but
before the biological process. Pumping to the EQ tank from the headworks would be
required. Further analysis of the plant's hydraulic profile is needed to determine conveyance
requirements from the EQ tank to the aeration basin. As presented in Figure U6.1, the plant
occasionally experiences a maximum daily flow up to 2.5 times greater than the average
daily flow. The flow equalization tank will serve to shave off the peak flows and store the
volume for treatment during lower flow periods.
Table U6-2: Historical Wastewater Flows
Historical Monthly - Average Daily Flow (Gallons)
Date
Average Daily
Flow
Maximum Daily Flow
February 2015
24,000
47,000
March 2015
20,000
28,000
April 2015
44,000
88,000
May 2015
42,000
105,000
June 2015
28,000
40,000
July 2015
31,000
51,000
August 2015
32,000
57,000
September 2015
28,000
38,000
October 2015
27,000
62,000
November 2015
36,000
91,000
December 2015
27,000
43,000
January 2016
37,000
93,000
February 2016
30,000
58,000
March 2016
52,000
106,000
April 2016
25,000
43,000
May 2016
25,000
33,000
June 2106
52,000
94,000
July 2016
30,000
60,000
6-5 TIMMONS GROUP
WASTEWATER FACILITY PLAN CHAPTER 6
August 2016
28,000
37,000
September 2016
28,000
43,000
October 2016
24,000
36,000
November 2016
26,000
36,000
December 2016
28,000
42,000
January 2017
30,000
50,000
February 2017
22,000
66,000
March 2017
17,000
27,000
April 2017
22,000
34,000
May 2017
28,000
48,000
June 2017
42,000
88,000
July 2017
29,000
42,000
Figure U6.1- Historical Wastewater Flows
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sa�oav
Z 40X0
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Oct•14 ]an-15 Aprr15 Jul-15 Oct.15 Ian -If) Apr-16 Jul•16 Oct•16 Jan•17 Apr•17 Jul-17 Oct•17
Date
#Average Deily Flow +Max DaiN FIo1,v
The existing 60,000 gpd wastewater treatment facility is configured as a dual "train"
30,000 gpd plant. The treatment facility consists of the following units: screening, activated
sludge, secondary clarification, coagulation, flocculation, sand filtration, UV disinfection,
cascade aeration, chlorination, dechlorination, sludge holding, and drying beds. Chlorination
and dechlorination apply only to the wastewater that is discharged through outfall 004, since
6-6 TIMMONS GROUP
WASTEWATER FACILITY PLAN CHAPTER 6
that outfall feeds a lake used for irrigation and has more stringent bacteria limits. A
schematic of the treatment process is shown below.
Figure U6-2: Keswick STP Process Schematic
UV Post
Aeration Clarifier Aera
Tank Tank Sand tion Creek
Filter
Screening
and Pump
Station
Aeration � Clarifier Sand
Tank Tank Filter
To upgrade the plant to a 90,000 gpd capacity system, modifications to several unit
processes will be required. Current capacities and sizes for most of the unit processes were
not available for review at the time of this study. Therefore, general planning level
recommendations are given for unit process upgrades. The recommended upgrades assume
all existing infrastructure has not reached the end of its useful life, nor will it reach the end of
its useful life before the upgrades are completed. An evaluation of existing plant
infrastructure should be performed to plan for any rehabilitation/replacement costs.
Wastewater flows by gravity through the bar screen before being pumped to the
aeration basins. The headworks pump station pumping equipment should be upgraded to
meet projected peak hourly flows. The pump station will pump flows to a Rotary Drum
Screen to be located on the EQ tank.
A 30,000 gallon EQ tank would require interior dimensions of approximately 20'L x
20'W x 12'SWD (side water depth). A small concrete pad would be positioned adjacent to
the EQ tank for two blowers to provide air to the EQ tank. Two submersible pumps in the
EQ tank are recommended to transfer flow from EQ to the biological process.
6.7 TIMMONS GROUP
WASTEWATER FACILITY PLAN
CHAPTER 6
As the 0.099 MGD flow tier requires an effluent limit of 8 mg/L for total nitrogen, the
extended aeration system must be modified to a biological nutrient removal (BNR) system.
The most economical alternative of transforming the existing extended aeration system to a
BNR system is with a Modified Ludzack-Ettinger (MLE) process. The MLE process adds an
anoxic basin before the aeration basin to transform nitrate to nitrogen gas. As nitrate is a
portion of total nitrogen, the MLE process reduces the total nitrogen content of the effluent.
Several piping modifications will also be required to establish the MLE process. The return
activated sludge (RAS) line will have to be re-routed to the front of the proposed anoxic
basin. An additional internal recycle line will have to be installed from the aerobic basin to
the anoxic basin. An internal recycle pump for each treatment train will also be required.
Exact size of the basins will be determined during design, once typical influent mass loading
rates are known. To meet the recommended 90,000 gpd capacity, a third treatment train
(including a secondary clarifier) with a capacity of 30,000 gpd and utilizing the MLE process
would be constructed.
Available space on site would host the new EQ tank, third treatment train, and anoxic
basins. Certain wastewater manufacturers can provide a single tank structure to house all
three of the new basins. This will efficiently utilize limited available space.
The 0.099 MGD flow tier also requires an effluent limit of 1 mg/L for total
phosphorus. A BNR process for removing phosphorus is not recommended for the Keswick
STP. This is because a BNR process for phosphorus removal requires stricter operational
attention than is typically provided for small scale treatment plants such as Keswick STP.
Additionally, due to the potential seasonal changes in wastewater quantity and quality,
maintaining the required microbial populations for phosphorus removal could prove overly
difficult. Therefore, chemical removal of phosphorus is recommended.
The existing coagulation/flocculation system and sand filters are a viable alternative
for phosphorus removal (and further nitrogen removal). The existing chemical pumps and
storage would have to be upsized for buildout flows. Additional sand filters would be
required to meet buildout flows. The existing building appears to have adequate space for
6-8 TIMMONS GROUP
WASTEWATER FACILITY PLAN CHAPTER 6
the installation of additional filters. Alternatively, other filtration methods may be employed,
such as two -stage filtration, deep -bed upflow continuous backwash filters, or cloth media
disk filters. Phosphorus, after being coagulated and flocculated in larger particles, would be
filtered out from the final effluent.
Upgrades to the UV disinfection system, cascade aeration structure, and sludge
storage are recommended at the buildout flows. Additional analysis of the site electrical and
SCADA is recommended to determine if the existing systems have available capacity for the
upgrade power requirements and controls.
As the projected average daily flows for Phase 1A, Phase 1B, Phase 2, and Phase 3
upgrades shown in Table U6.1 are less than the existing plant capacity of 60,000 gpd, no
improvements to the STP are recommended in conjunction with the renovation and
expansion plans for Keswick Hall & Golf Club. Because of the change in permit limits above
60,000 gpd, it is recommended to move forward with all of the system upgrades after
completion of Phase 3 and before a maximum of 14 single family residences are built.
Phase 2 improvements project an average daily flow of approximately 52,500 gpd,
which is within 10% of the 57,000 gpd for the 95% capacity reopener. Once Phase 2 has
been constructed and is in operation, an evaluation of wastewater flows should be performed
to determine the probability of Phase 3 flows triggering the capacity reopener. Additionally,
once Phase 3 is implemented, if seasonal peak daily flows stress the STP beyond its capacity,
moving forward with the recommended upgrades may be considered.
U6.3 COLLECTION SYSTEM
Since the 2000 Facilities Plan, the sanitary sewer collection system was expanded to
the eastern portions of the Keswick subdivision. Approximately 17,000 linear feet of pipe
was installed.
The collection system must be able to handle the projected buildout wastewater
flows. The required capacity for sewers is based on peak hourly flows. For small flows (less
6-9 TIMMONS GROUP
WASTEWATER FACILITY PLAN CHAPTER 6
than a million gallons per day, MGD), the peak hour condition is commonly determined from
the calculation:
Required Capacity in MGD = (3.5) (Average Daily Flow in MGD) 0.807
Based on a design flow of 90,000 gpd, the peak hourly flow (and required pipe
capacity) is 0.50 MGD. These flows will occur in the trunk sewers leading directly to the
treatment facility, while lower flows will occur in branch lines.
The existing sewers at Keswick are generally 8-inch diameter, the minimum required
by Virginia Department of Health (VDH). Installed at the minimum slope allowed by VDH,
8-inch lines are capable of carrying at least 0.54 MGD. At slightly steeper slopes (such as
that of the "trunk" sewers leading directly to the existing wastewater plant), 8-inch lines are
easily capable of carrying the maximum total peak flows anticipated. There are two small
portions of the collection system (see existing sewer map in Chapter 1) unable to be served
by gravity, instead there are existing low pressure sewer networks comprised of individual
grinder pump stations at each affected lot. The pump stations manifold into a common force
main which discharges into the gravity system. Therefore, it is assumed that all sewer lines in
the Keswick collection system are adequate for the projected flows.
U6.4 SUMMARY
The existing wastewater collection and treatment system is readily expandable to
meet the required ultimate demands of the Estate. The existing STP would require upgrades
to the headworks, pump station, coagulation/flocculation system, filters, UV disinfection, and
cascade aeration structure. Additionally, a new Flow EQ tank would be required. The
extended aeration process would be converted to an MLE process and a third treatment train
would be installed. The existing collection system linework is already sized sufficiently to
carry ultimate peak flows.
A more detailed list of critical project components and the engineer's opinion of probable
construction costs (OPCC) for each are provided in Appendix A. The engineer's OPCC is
6-10 TIMMONS GROUP
WASTEWATER FACILITY PLAN CHAPTER 6
based in large part on assumptions made from planning level details of proposed renovation
and expansion activities. Reasonable assumptions were made as to the project intent based on
the evaluated information provided. Furthermore, reasonable assumptions were made as to
how the authorities having jurisdiction will interpret and apply regulations, codes,
ordinances, etc., but the actual project requirements determined during design by the
authorities having jurisdiction may vary from the assumptions presented herein. The
engineer's OPCC is based on best judgment, experience, and being qualified professionals
generally familiar with the construction industry. Because the engineer has no control over
the cost of labor, materials, equipment, services furnished by others, or over competitive
bidding or market conditions, the engineer cannot guarantee that actual construction costs
will not vary from the OPCC presented. The OPCC provided do not include costs for
financing, property, or easement acquisition services. The following OPCC are presented in
2017 dollars and costs should be adjusted in subsequent years.
The engineer's OPCC to upgrade the STP to 90,000 GPD capacity is $1,859,000. Refer to
the detailed OPCC in Appendix A.
6-11 TIMMONS GROUP
WASTEWATER FACILITY PLAN
CHAPTER 6
U6.5 PHOTOS OF EXISTING STP
Photo WW1 — Headworks.
Photo WW2 — Aeration Tank.
6-12 TIMMONS GROUP . ':'•.
WASTEWATER FACILITY PLAN CHAPTER 6
Photo WW3 — Coagulation and Flocculation.
Photo WW4 — Sand Filters.
v-
1w
N
4o
6-13 TIMMONS GROUP . ':'•.
WASTEWATER FACILITY PLAN CHAPTER 6
Photo WW5 — UV Disinfection.
Photo WW6 — Cascade Aeration.
6-14 TIMMONS GROUP . ':'•.
TABLE OF CONTENTS
APPENDIX A
OPINION OF PROBABLE CONSTRUCTION COSTS
TIMMONS GROUP .••':••.
Keswick Hall & Golf Club December 1, 2017
Water and Wastewater Facilities Plan - 2017 Update
Base Improvement W1 - Dedicated Internal Fire Protection
30,000 Gallon Ground Storage Tank
and 500 gpm Diesel -Driven Fire Pump
Probable Construction Cost
Item
Description
Quantity Units
Unit $
Total Cost
1
Mobilization
1 LS
$15,000
$15,000
2
20' x 20' Precast Concrete Building
1 LS
$60,000
$60,000
3
Building Foundation
1 LS
$10,000
$10,000
4
Building Setting
1 LS
$10,000
$10,000
5
18' X 16' Bolted Steel Tank with
1 LS
$90,000
$90,000
Insulation and Heater
6
Tank Foundation and Site Prep
1 LS
$20,000
$20,000
7
Skid Mounted 500 gpm Diesel Pump
1 LS
$60,000
$60,000
(with Controls, Piping, and Valves)
8
Pump Skid Setting
1 LS
$5,000
$5,000
9
Interior Piping, Valves and Installation
1 LS
$20,000
$20,000
10
Telemetry and Instrumentation
1 LS
$10,000
$10,000
11
Electrical & Mechanical
1 LS
$40,000
$40,000
12
Site Prep, Grading, and E&S
1 LS
$20,000
$20,000
13
Site Piping and Isolation Valves
1 LS
$20,000
$20,000
14
Control Valve and Vault
1 LS
$15,000
$15,000
15
4" D.I. Tank Supply Pipe
100 LF
$55
$5,500
16
8" D.I. Fire Waterline
700 LF
$85
$59,500
17
Connect to Ex. Waterline
4 Ea.
$7,500
$30,000
Sub -total
$490,000
Construction Contingency
15%
$73,500
Total Probable Construction Cost
$563,500
Professional Services Prior to Construction
Design Engineering
10.0%
$56,350
Geotechnical Engineering
1.5%
$8,453
Utility
Location and Survey (See Note #1)
0.0%
$0
Wetland Delineation / Environmental Assessment / Permitting (See Note #2)
0.0%
$0
Easement Acquisition
and Easement Plats (See Note #2)
0.0%
$0
Legal and Owner Administration
5.0%
$28,175
Sub -total
$92,978
Professional Services During Construction
Construction Administration / Construction Observation
5.0%
$28,175
Materials Testing
1.0%
$5,635
Construction Survey
1.0%
$5,635
Sub -total
$39,445
Total Probable Project Cost
$696,000
Notes:
1. Already completed.
2. Not anticipated or included.
3. The above project costs do no include financing or property or easement purchase costs.
Keswick Hall & Golf Club December 1, 2017
Water and Wastewater Facilities Plan - 2017 Update
Base Improvement W1 - Internal Fire Protection + 500 gpm Hose Stream
60,000 Gallon Ground Storage Tank
and 1,000 gpm Diesel -Driven Fire Pump
Probable Construction Cost
Item
Description
Quantity Units
Unit $
Total Cost
1
Mobilization
1 LS
$15,000
$15,000
2
20' x 20' Precast Concrete Building
1 LS
$60,000
$60,000
3
Building Foundation
1 LS
$10,000
$10,000
4
Building Setting
1 LS
$10,000
$10,000
5
24' X 18' Bolted Steel Tank
1 LS
$110,000
$110,000
(with Insulation and Heater)
6
Tank Foundation
1 LS
$20,000
$20,000
7
Skid Mounted 1,000 gpm Diesel Pump
1 LS
$65,000
$65,000
(with Controls, Piping, and Valves)
8
Pump Skid Setting
1 LS
$5,000
$5,000
9
Interior Piping, Valves and Installation
1 LS
$20,000
$20,000
10
Telemetry and Instrumentation
1 LS
$10,000
$10,000
11
Electrical & Mechanical
1 LS
$40,000
$40,000
12
Site Prep, Grading, and E&S
1 LS
$20,000
$20,000
13
Site Piping and Isolation Valves
1 LS
$20,000
$20,000
14
Control Valve and Vault
1 LS
$15,000
$15,000
15
4" D.I. Tank Supply Pipe
100 LF
$55
$5,500
16
12" D.I. Fire Waterline
700 LF
$100
$70,000
17
Connect to Ex. Waterline
4 Ea.
$7,500
$30,000
Sub -total
$525,500
Construction Contingency
15%
$78,825
Total Probable Construction Cost
$604,325
Professional Services Prior to Construction
Design Engineering
10.0%
$60,433
Geotechnical Engineering
1.5%
$9,065
Utility
Location and Survey (See Note #1)
0.0%
$0
Wetland Delineation / Environmental Assessment / Permitting (See Note #2)
0.0%
$0
Easement Acquisition
and Easement Plats (See Note #2)
0.0%
$0
Legal and Owner Administration
5.0%
$30,216
Sub -total
$99,714
Professional Services During Construction
Construction Administration / Construction Observation
5.0%
$30,216
Materials Testing
1.0%
$6,043
Construction Survey
1.0%
$6,043
Sub -total
$42,303
Total Probable Project Cost
$746,000
Notes:
1. Already completed.
2. Not anticipated or included.
3. The above project costs do no include financing or property or easement purchase costs.
Keswick Hall & Golf Club December 1, 2017
Water and Wastewater Facilities Plan - 2017 Update
Base Improvement W1 - Internal Fire Protection + 1,000 gpm ISO/IFC Fire Flow
90,000 Gallon Ground Storage Tank
and 1,500 gpm Diesel -Driven Fire Pump
Probable Construction Cost
Item
Description
Quantity Units
Unit $
Total Cost
1
Mobilization
1 LS
$15,000
$15,000
2
20' x 20' Precast Concrete Building
1 LS
$60,000
$60,000
3
Building Foundation
1 LS
$10,000
$10,000
4
Building Setting
1 LS
$10,000
$10,000
5
26' X 24' Bolted Steel Tank
1 LS
$125,000
$125,000
(with Insulation and Heater)
6
Tank Foundation
1 LS
$20,000
$20,000
7
Skid Mounted 1,500 gpm Diesel Pump
1 LS
$70,000
$70,000
(with Controls, Piping, and Valves)
8
Pump Skid Setting
1 LS
$5,000
$5,000
9
Interior Piping, Valves and Installation
1 LS
$20,000
$20,000
10
Telemetry and Instrumentation
1 LS
$10,000
$10,000
11
Electrical & Mechanical
1 LS
$40,000
$40,000
12
Site Prep, Grading, and E&S
1 LS
$20,000
$20,000
13
Site Piping and Isolation Valves
1 LS
$20,000
$20,000
14
Control Valve and Vault
1 LS
$15,000
$15,000
15
4" D.I. Tank Supply Pipe
100 LF
$55
$5,500
16
12" D.I. Fire Waterline
700 LF
$100
$70,000
17
Connect to Ex. Waterline
4 Ea.
$7,500
$30,000
Sub -total
$545,500
Construction Contingency
15%
$81,825
Total Probable Construction Cost
$627,325
Professional Services Prior to Construction
Design Engineering
10.0%
$62,733
Geotechnical Engineering
1.5%
$9,410
Utility
Location and Survey (See Note #1)
0.0%
$0
Wetland Delineation / Environmental Assessment / Permitting (See Note #2)
0.0%
$0
Easement Acquisition
and Easement Plats (See Note #2)
0.0%
$0
Legal and Owner Administration
5.0%
$31,366
Sub -total
$103,509
Professional Services During Construction
Construction Administration / Construction Observation
5.0%
$31,366
Materials Testing
1.0%
$6,273
Construction Survey
1.0%
$6,273
Sub -total
$43,913
Total Probable Project Cost
$775,000
Notes:
1. Already completed.
2. Not anticipated or included.
3. The above project costs do no include financing or property or easement purchase costs.
Keswick Hall & Golf Club December 1, 2017
Water and Wastewater Facilities Plan - 2017 Update
Base Improvement W2 - Domestic System
Groundwater Well, 18,000 Gallon Ground
Storage Tank, and 250 gpm Booster Pumps
Probable Construction Cost
Item
Description
Quantity
Units
Unit $
Total Cost
1
Mobilization
1
LS
$15,000
$15,000
2
6" Class I I B Groundwater Well Drilling
600
VF
$35
$21,000
3
Well Testing and Disinfecting
1
LS
$7,500
$7,500
4
4" Vertical Turbine Submersible Well
1
LS
$10,000
$10,000
Pump with Controls
5
3" Sch. 40 Riser Pipe and Valves
550
VF
$30
$16,500
6
3" D.I. Dishcarge Pipe and Installation
100
LF
$50
$5,000
7
11' X 28' Horizontal Welded Steel Tank
1
LS
$35,000
$35,000
8
Tank Setting
1
LS
$10,000
$10,000
9
Tank Heater
1
LS
$5,000
$5,000
10
Tank Saddles
1
LS
$10,000
$10,000
11
Pipe Heat Trace and Insulation
1
LS
$10,000
$10,000
12
Instrumentation
1
LS
$10,000
$10,000
13
250 gpm Electric Booster Pumps
2
Ea.
$7,500
$15,000
14
Booster Pump Installation and Startup
1
LS
$10,000
$10,000
15
Interior Piping and Valves
1
LS
$5,000
$5,000
16
Electrical
1
LS
$50,000
$50,000
17
Site Prep, Grading, and E&S
1
LS
$20,000
$20,000
18
Site Piping and Isolation Valves
1
LS
$20,000
$20,000
Sub -total
$275,000
Construction
Contingency
15%
$41,250
Total Probable Construction Cost
$316,250
Professional Services Prior to Construction
Design Engineering
10.0%
$31,625
Geotechnical Engineering
2.0%
$6,325
Geophysical Survey
5.0%
$15,813
Utility
Location and Survey
3.0%
$9,488
Wetland Delineation / Environmental
Assessment / Permitting
1.0%
$3,163
Easement Acquisition
and Easement Plats (See Note #1)
0.0%
$0
Legal and Owner Administration
5.0%
$15,813
Sub -total
$82,225
Professional Services During Construction
Construction Administration / Construction Observation
5.0%
$15,813
Materials Testing
1.0%
$3,163
Construction Survey
1.0%
$3,163
Sub -total
$22,138
Total Probable Project Cost
$421,000
Notes:
1. Not anticipated or included.
2. The above project costs do no include financing or property or easement purchase costs.
3. It is assumed that the existing generator is adequate to support pump upgrade.
4. It is assumed that no modifactions to the pump house structure will be required.
5. It is assumed that no additional water treatment will be required.
Keswick Hall & Golf Club
Water and Wastewater Facilities Plan - 2017 Update
Base Improvement W3 - External Fire Protection
30,000 Gallon Ground Storage Tank and 500 gpm
Booster Pump in Existing Pump House
December 1, 2017
Probable Construction Cost
Item
Description
Quantity Units
Unit $
Total Cost
1
Mobilization
1 LS
$15,000
$15,000
2
18' X 16' Bolted Steel Tank
1 LS
$50,000
$50,000
3
Active Mixer
1 LS
$20,000
$20,000
4
Tank Foundation and Site Prep
1 LS
$20,000
$20,000
5
500 gpm Electric Booster Pump
1 Ea.
$15,000
$15,000
6
Booster Pump Installation and Startup
1 LS
$10,000
$10,000
7
Interior Piping and Valves
1 LS
$10,000
$10,000
8
Telemetry and Instrumentation
1 LS
$10,000
$10,000
9
Electrical
1 LS
$50,000
$50,000
10
Generator Upgrade
1 LS
$40,000
$40,000
11
Site Prep, Grading, and E&S
1 LS
$20,000
$20,000
12
Site Piping and Isolation Valves
1 LS
$20,000
$20,000
13
Retrofit Hydrants to System
17 Ea.
$8,500
$144,500
Sub -total
$424,500
Construction Contingency
15%
$63,675
Total Probable Construction Cost
$488,175
Professional Services Prior to Construction
Design Engineering
10.0%
$48,818
Geotechnical Engineering
1.5%
$7,323
Utility Location and Survey
3.0%
$14,645
Wetland Delineation / Environmental
Assessment / Permitting
1.0%
$4,882
Easement Acquisition
and Easement Plats (See Note #1)
0.0%
$0
Legal and Owner Administration
5.0%
$24,409
Sub -total
$100,076
Professional Services During Construction
Construction Administration / Construction Observation
5.0%
$24,409
Materials Testing
1.0%
$4,882
Construction Survey
1.0%
$4,882
Sub -total
$34,172
Total Probable Project Cost
$622,000
Notes:
1. Not anticipated or included.
2. The above project costs do no include financing or property or easement purchase costs.
3. It is assumed that the existing generator is adequate to support pump upgrade.
4. It is assumed that no modifactions to the pump house structure will be required.
5. It is assumed that no additional water treatment will be required.
Keswick Hall & Golf Club December 1, 2017
Water and Wastewater Facilities Plan - 2017 Update
Alternate Improvement W4 - Domestic + External Fire Protection, Ground Storage
Groundwater Well, 50,000 Gallon Ground
Storage Tank, Booster Pump Upgrades
Probable Construction Cost
Item
Description
Quantity
Units
Unit $
Total Cost
1
Mobilization
1
LS
$15,000
$15,000
2
6" Class I I B Groundwater Well Drilling
600
VF
$35
$21,000
3
Well Testing and Disinfecting
1
LS
$7,500
$7,500
4
4" Vertical Turbine Submersible Well
1
LS
$10,000
Pump with Controls
$10,000
5
3" Sch. 40 Riser Pipe and Valves
550
VF
$30
$16,500
6
3" D.I. Dishcarge Pipe and Installation
100
LF
$50
$5,000
7
22' X 18' Bolted Steel Tank
1
LS
$75,000
$75,000
8
Active Mixer
1
Ea.
$20,000
$20,000
9
Tank Foundation and Site Prep
1
LS
$20,000
$20,000
10
500 gpm Electric Booster Pump
1
Ea.
$15,000
$15,000
11
250 gpm Electric Booster Pumps
2
Ea.
$7,500
$15,000
12
Booster Pump Installation and Startup
1
LS
$20,000
$20,000
13
Interior Piping and Valves
1
LS
$15,000
$15,000
14
Telemetry and Instrumentation
1
LS
$10,000
$10,000
15
Electrical
1
LS
$60,000
$60,000
16
Generator Upgrade
1
LS
$40,000
$40,000
17
Site Prep, Grading, and E&S
1
LS
$20,000
$20,000
18
Site Piping and Isolation Valves
1
LS
$20,000
$20,000
19
Retrofit Hydrants to System
17
Ea.
$8,500
$144,500
Sub -total
$549,500
Construction
Contingency
15%
$82,425
Total Probable Construction Cost
$631,925
Professional Services Prior to Construction
Design Engineering
10.0%
$63,193
Geotechnical Engineering
1.5%
$9,479
Geophysical Survey
3.0%
$18,958
Utility
Location and Survey
3.0%
$18,958
Wetland Delineation / Environmental
Assessment / Permitting
1.0%
$6,319
Easement Acquisition
and Easement Plats (See Note #1)
0.0%
$0
Legal and Owner Administration
5.0%
$31,596
Sub -total
$148,502
Professional Services During Construction
Construction Administration / Construction Observation
5.0%
$31,596
Materials Testing
1.0%
$6,319
Construction Survey
1.0%
$6,319
Sub -total
$44,235
Total Probable Project Cost
$825,000
Notes:
1. Not anticipated or included.
2. The above project costs do no include financing or property or easement purchase costs.
3. It is assumed that no modifactions to the pump house structure will be required.
4. It is assumed that no additional water treatment will be required.
Keswick Hall & Golf Club December 1, 2017
Water and Wastewater Facilities Plan - 2017 Update
Alternate Improvement W5 - Domestic + External Fire Protection, Elevated Storage
Groundwater Well, 100,000 Gallon
Elevated Storage Tank
Probable Construction Cost
Item
Description
Quantity Units
Unit $
Total Cost
1
Mobilization
1 LS
$15,000
$15,000
2
6" Class I I B Groundwater Well Drilling
600 VF
$35
$21,000
3
Well Testing and Disinfecting
1 LS
$7,500
$7,500
4
4" Vertical Turbine Submersible Well
1 LS
$10,000
Pump with Controls
$10,000
5
3" Sch. 40 Riser Pipe and Valves
550 VF
$30
$16,500
6
3" D.I. Dishcarge Pipe and Installation
100 LF
$50
$5,000
7
0.1 MMG x 200' EWST Including
1 LS
$1,200,000
$1,200,000
Foundation and Painting
8
Active Mixer
1 Ea.
$20,000
$20,000
9
Telemetry and Instrumentation
1 LS
$10,000
$10,000
10
Electrical
1 LS
$30,000
$30,000
11
Site Prep, Grading, and E&S
1 LS
$20,000
$20,000
12
Site Piping and Isolation Valves
1 LS
$20,000
$20,000
13
Retrofit Hydrants to System
17 Ea.
$8,500
$144,500
Sub -total
$1,519,500
Construction Contingency
15%
$227,925
Total Probable Construction Cost
$1,747,425
Professional Services Prior to Construction
Design Engineering
10.0%
$174,743
Geotechnical Engineering
0.6%
$10,485
Geophysical Survey
1.0%
$17,474
Utility Location and Survey
1.0%
$17,474
Wetland Delineation / Environmental
Assessment / Permitting
0.5%
$8,737
Easement Acquisition
and Easement Plats (See Note #1)
0.0%
$0
Legal and Owner Administration
5.0%
$87,371
Sub -total
$316,284
Professional Services During Construction
Construction Administration / Construction Observation
5.0%
$87,371
Materials Testing
1.0%
$17,474
Construction Survey
1.0%
$17,474
Sub -total
$122,320
Total Probable Project Cost
$2,186,000
Notes:
1. Not anticipated or included.
2. The above project costs do no include financing or property or easement purchase costs.
3. It is assumed that no additional water treatment will be required.
Keswick Hall & Golf Club December 1, 2017
Water and Wastewater Facilities Plan - 2017 Update
WWTP Upgrade to 90,000 gpd
Probable Construction Cost
Item
Description
Quantity Units
Unit $
Total Cost
1
Mobilization
1 LS
$50,000
$50,000
2
Electrical and Controls
1 LS
$100,000
$100,000
3
Site Prep, Grading, and E&S
1 LS
$50,000
$50,000
4
Maintenance of Service
1 LS
$10,000
$10,000
5
Site Piping and Valves
1 LS
$15,000
$15,000
6
Headworks Screening:
1 LS
$44,995
$44,995
CleanTek RotoSieve - Equipment
7
CleanTek RotoSieve - Installation
2 WK
$10,000
$20,000
8
Headworks PS Upgrade
1 LS
$50,000
$50,000
9
Dutchland Precast Tank for:
1 LS
$600,000
$600,000
EQ Tank, Third Treatment Train,
Pre -Anoxic Tanks
10
MILE Internal Recycle Pumps for
2 Ea.
$10,000
$20,000
Existing Trains
11
MILE Piping Modifications for Existing
2 Ea.
$5,000
$10,000
Trains
12
Coag/Floc Chemical Pumps
2 Ea.
$5,000
$10,000
13
Coag/Floc Storage
1 LS
$2,500
$2,500
14
Filter Upgrade: Aqua -Aerobic 2 Disk
2 Ea.
$55,000
$110,000
MiniDisk - Equipment
15
Aqua -Aerobic MiniDisk - Install
3 WK
$10,000
$30,000
16
Filter Piping Modifications
1 LS
$5,000
$5,000
17
UV Disinfection Upgrade
1 LS
$50,000
$50,000
18
Cascade Aeration Upgrade
1 LS
$50,000
$50,000
19
Sludge Storage Upgrade
1 LS
$75,000
$75,000
Sub -total
$1,302,495
Construction Contingency
15%
$195,374
Total Probable Construction Cost
$1,497,869
Professional Services Prior to Construction
Design Engineering
10.0%
$149,787
Geotechnical Engineering
0.6%
$8,987
Utility Location and Survey
1.0%
$14,979
Wetland Delineation / Environmental
Assessment / Permitting
0.5%
$7,489
Easement Acquisition and Easement Plats (See Note #1)
0.0%
$0
Legal and Owner Administration
5.0%
$74,893
Sub -total
$256,136
Professional Services During Construction
Construction Administration
/ Construction Observation
5.0%
$74,893
Materials Testing
1.0%
$14,979
Construction Survey
1.0%
$14,979
Sub -total
$104,851
Total Probable Project Cost
$1,859,000
Notes:
1. The above project costs do no include financing or property or easement purchase costs.
TABLE OF CONTENTS
APPENDIX B
WATER AND WASTEWATER FACILITIES PLAN - NOVEMBER 3, 2000
TIMMONS GROUP .••':••.
WATER AND WASTEWATER
FACILITIES PLAN
For
",-a
KESWICK ESTATES
& SUBDIVISION
November 3, 2000
Prepared by
I
Engineers • Surveyors • Planners • Landscape Architects • Environmental Scientists
Geographic Information Systems Consultants • Construction Managers
711 N. Courthouse Road • Richmond, Va. 23236-4099
WATER AND WASTEWATER
FACILITIES PLAN
For
KESWICK ESTATES
& SUBDIVISION
A
4TH Qv
0 `
/ 0
O BRI,%N R. HOUSTON
QUALITY ASSURANCE
STATEMENT
A Quality Control and Assurance review has
been performed on this document in accord-
ance with the TIMMONS Quality Plan. The
undersigned states that this document has
been checked and reviewed in a manner
/U No.31127 ,
0
s
Ilksxoxaz. AVDale
V�, Vb.�004W/
commensurate with the level of detail
for the type of submittal indicated below.
Brian R. Houston
Projec! Manager
t 13/oo
FINAL
Type of Submittal
Prepared By:
Checked By.
Reviewed By:
BRH, FBV
BRH, FBV
BRH, FBV
November 3, 2000
Prepared by
�' TABLE OF CONTENTS
TABLE OF CONTENTS
EXECUTIVE SUMMARY
CHAPTER I — INTRODUCTION
1.1 Purpose..............................................................................................................1-1
1.2 Scope..................................................................................................................1-1
CHAPTER 2 — DEMANDS
2.1 Domestic Demands............................................................................................2-1
Table 2-1: Current Daily Domestic Water Consumption
Table 2-2: Projected Daily Domestic Water Consumption
2.2 Irrigation Demands............................................................................................2-4
Table 2-3: Current Daily Water Consumption (with Irrigation)
Table 2-4: Projected Daily Water Consumption (with Irrigation)
CHAPTER 3 — EXISTING WATER SYSTEM
3.1 History...............................................................................................................3-1
Figure 3-1: Supply Timeline
Photograph 3-1: Eastern Supply (Old)
Photograph 3-2: Eastern Supply (Current)
Photograph 3-3: Wells No. I and 3
Photograph 3-4: Well No. 2
3.2 Sources...............................................................................................................3-3
Figure 3-2: Typical Cone of Influence
Figure 3-3: Well Locations
Table 3-1: Well Characteristics
3.3 Supply Infrastructure..........................................................................................3-7
Figure 3-4: Water System Schematic
3.4 Distribution Infrastructure..................................................................................3-8
Figure 3-5: Existing Water System
CHAPTER 4 — EXISTING WASTEWATER SYSTEM
4.1 History...............................................................................................................4-1
4.2 Collection System..............................................................................................................4-2
Figure 4-1: Wastewater Collection System
4.3 Treatment System...............................................................................................4-3
Table 4-1: Design Capacity Computations
Figure 4-2: Keswick STP Process Schematic
Photograph 4-1: Aeration Tanks
Photograph 4-2: Sand Filter
TOC-I
TIMMONS=
Iff TABLE OF CONTENTS
CHAPTER 5 — WATER FACILITIES PLAN
5.1
General...............................................................................................................5-1
5.2
Source Options...................................................................................................5-1
5.2.1 Wells -Only Supply
Figure 5-1: Everona Limestone Location
5.2.2 Pond -Supplied Irrigation
5.3
Storage & Pumping............................................................................................5-5
5.4
Linework............................................................................................................5-7
Figure 5-2: Club Drive Waterline Replacement Alternative
5.5
Summary & Recommendations..........................................................................5-9
5.5.1 Supply (Domestic & Irrigation) Alternatives
5.5.2 Fire Protection Alternatives
5.5.3 Conclusion
CHAPTER 6 WASTEWATER FACILITIES PLAN
6.1 Treatment........................................................................................................... 6-1
6.2 Linework............................................................................................................6-2
Figure 6-2: Future Collection System Development
6.3 Summary & Recommendations..........................................................................6-4
TOC-2
TIMMONS=
EXECUTIVE SUMMARY
EXECUTIVE SUMMARY
This Study was commissioned to determine Keswick's ultimate future water and
wastewater demands, and the infrastructure improvements and additions required to support
those demands. Based on existing per -unit demands for various uses and the projected
quantity of each type of use at Keswick's buildout, ultimate domestic water capacity
requirements were calculated at 101,000 gallons per day (gpd). The addition of residential
irrigation demands results in an irrigation season demand of 217,000 gallons. Although
wastewater treatment capacities are typically based on average day, the seasonality of
Keswick's demands warrant design for peak month, for a 110,000 gpd capacity.
The existing well -supplied water system relies on the high yielding Everona
Limestone geologic formation which passes through the easternmost corner of the Estate
property. The system is adequately designed for continued expansion of the Inn and
appurtenant uses as well as the subdivision, however additional infrastructure will be
required in order to meet ultimate demands. Based on cost considerations, the recommended
alternative for domestic and residential irrigation supply is expansion of the existing well
field, which will require the purchase of additional property overlying the Everona
Limestone geologic formation. Based on the need to provide adequate (1,000 gallon per
minute) fire suppression capacity throughout the distribution system, elevated or pressurized
storage in the northern portion of the Estate is recommended. Provision of such eliminates
the need for any significant upgrades to the distribution system or the addition of pumping
capacity. Including construction of waterlines in currently undeveloped portions of the
subdivision, estimated total costs of the recommended water system upgrades are
approximately $855,000, and are itemized as follows:
® TIMMONS
`FL EXECUTIVE SUMMARY
• Source: Five new wells ................................... 5 @ $25,000 ........ $125,000
• Linework: 4-inch from expanded wellfield ............ $35,000 .......... $35,000
• Linework: Future 8-inch and Upgrade 4-inch ...... $210,000 ........ $210,000
• Pressure or Elevated Storage: 70,500 P-allons....... $375,000 ........ $375,000
TOTAL CONSTRUCTION COST ......................................................... $745,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (15%)..... $110,000
TOTAL PROJECT COSTS............................................................... $855,000
The existing wastewater treatment system is an adequately designed dual "train"
60,000 gpd facility. The addition of a new 50,000 gpd train and the upgrade of the existing
facility's headworks and final treatment components will permit the facility to process
projected ultimate flows. Keswick's ultimate peak wastewater flows do not exceed the
capacity of a minimum -sized and minimum -sloped sewer, so continued adherence to the
Virginia Department of Health's design requirements for sewers will ensure provision of
adequate linework capacity. Including expansion of the collection system into future
development areas, the costs of the required wastewater system upgrades are estimated at
$1,185,000, itemized as follows:
• Treatment: Add 50,000 gpd train ................................................. $350,000
• Headworks: Upgrade for 110,000 gpd capacity ............................. $80,000
• Final Treatment: Upgrade for 110,000 gpd capacity ...................... $50,000
• Linework: Future 8-inch sewers...................................................$550,000
TOTAL CONSTRUCTION COST ...................................................... $1,030,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (15%)..... S 155,000
TOTAL PROJECT COSTS............................................................ $1,185,000
TIMMONS=
>10t INTRODUCTION
1.1 PURPOSE
CHAPTER I
INTRODUCTION
1.1 PURPOSE
Keswick's recent plans for expansion of the Inn and its appurtenant buildings has
required a revisitation of design criteria for the water and wastewater systems serving it. The
existing systems were sized without the benefit of foreknowledge of the now planned
improvements or of the extent of domestic and residential irrigation demands. Determination
of the additional capacity requirements is necessary as a first step in planning the utility
infrastructure necessary to support the desired development.
As these systems were not designed for the now -planned ultimate buildout scenario of
the Estate, they must be reevaluated and where deficiencies are identified, a plan must be
established for their upgrade to meet demands. This document serves as that plan - a guide
and a basis of design for future upgrades and expansion of the systems.
1.2 SCOPE
The scope of this Study is as follows:
• Evaluate existing domestic and residential irrigation demands and based on them,
provide estimates of future capacity requirements for both water and wastewater
systems.
• Examine the existing systems to determine deficiencies, if any, as related to their
ability to meet the projected ultimate demands.
db TIMM NS=
INTRODUCTION 1.2 SCOPE
• Evaluate alternatives for upgrade or additions to the existing systems to meet
projected ultimate demands, and make recommendations.
• Provide cost estimates for the recommended upgrades and additions.
1-2
:.10 DEMAND PROJECTIONS
2.1 DOMESTic DEMANDS
CHAPTER 2
DEMAND PROJECTIONS
1 2.1 DOMESTIC DEMANDS
In order to determine the requirements of the ultimate water supply, storage, and
distribution, and wastewater collection, treatment, and disposal facilities, accurate estimates
of ultimate demands must be made. In many cases, demand estimates must be based on
accepted standard values for each type of connection to the systems. In a case where existing
demands are representative of the types of demands ultimately anticipated, actual per -
connection demands for existing uses can be extrapolated to determine ultimate case
demands. The latter is the methodology utilized for this study.
The first step of the analysis is determination of existing per -connection demands for
the various types of uses. To this end, billing records were provided for the period between
July 1998 and February 2000 for both Estate and residential demands. These water billing
records were evaluated on two bases: Peak month, and average day.
Table 2-1 summarizes the analysis for existing demands. Average domestic use
water billings totaled approximately 443,000 gallons per month. Another 50,000 gallons per
month is estimated for unmetered (and therefore unbilled) demands at the golf course
maintenance and wastewater treatment facilities, for a total of 493,000 gallons per month.
Current (as of February 2000) average daily demand is therefore estimated at 16,425 gallons
per day (gpd).
III ® TIMMONS=
R DEMAND PROJECTIONS
2.1 DOMESTIC DEMANDS
Tahle 2-1 • riirrPnt naiiv nnmestlr Watar ('nncumntinn
Peak Month - qal per
Avera a Month -gal per
Location
Units
month da d•unit
month qpd d•unit
Notes
Inn
48
380,000
12,667
293
286,500
9,550 284
Per Unit values based on 90% booking during Peak
Month and 70 % booking on Average
Clubhouse
111,000
3,700
66,950
2,232
Pavilion
42,500
1,417
15,600
520
Administration
7,200
240
2,290
76
Subtotal - Inn &
Peak Month total is based on highest month of
Associated Uses
501,700
16, 723
371,340
12, 378
combined uses, and does not equal sum of peak
individual uses.
Maintenance
100,000
3,333
50,000
1,667
These Flows are currently unmetered, and are therefor
estimates only
Residences
12
122,240
4,075
340
71,406
2,380
200
Peak Month occurred with 12 residences filled,
Average over study period was 11 9 residences
Peak Month total is based on highest month of
Total Flow
686,321
22,877
492,746
16,425
combined uses + est, maintenance demand, and does
not equal sum of peak individual uses
Peak Day
26,280
Peaking Factor of 160% applied to average day; Peak
Day / Average Day of Peak Month - 115%
Note: Table I data is extracted from water billing data for the period between July 1998 and February 2000, except as otherwise noted.
In domestic -only systems, peak day demand is typically estimated at 1.6 times
average day, which for the above average daily demand is calculated as 26,280 gpd. Due to
the seasonality of Keswick's demands, this value was cross-checked against the peak month
conditions between July 1998 and February 2000. August 1998 domestic use water billings
totaled approximately 586,000 gallons. The addition of an estimated 100,000 gallons for the
unmetered golf course maintenance and wastewater treatment demands results in a peak
month of 686,000 gallons, or 22,877 gpd. The fact that the peak month's average day
demands are only 87% of the calculated peak day serves to confirm the validity of the peak
day calculation.
Projections for future demands were evaluated based on unit values determined from
Table 2-1 applied to buildout development plans for the Inn and Subdivision. The resulting
demand estimates are provided in Table 2-2, including a projected peak day demand of
101,265 gallons. The peak month calculation is also provided as a cross-check against peak
TIMMONS=
ff. DEMAND PROJECTIONS
2.1 DOMESTIC DEMANDS
day calculation. Peak month estimates in Table 2-2 are conservative, since the total is
calculated as the sum of all individual peaks. Individual peaks should not be expected to
occur simultaneously, so total peak is expected to be somewhat less than that indicated.
Even so, the estimated peak month's average day demands are still significantly less than
those estimated for peak day, so the calculated peak day value is considered valid.
Tah/e 2-2- Prniected Daily Dnmestir_ Water Cnnsumntinn
Peak Month - at per
Avera a Month - al Per
Location
Units
Notes
month
day
d•unit
month
gpd
d•unit
Inn
76
601,236
20,041 •
293
485,640
16,188
284
Totals based on 90% booking during Peak Month and
(targeted) 75 % booking on Average
Cottages
47
371,817
12,394•
293
300.330
10,011
284
see note for Inn
Clubhouse
222,000
7,400 .
133,890
4,463
All demands doubled for proposed
Pavilion
106,275
3,543 •
39,000
1,300
All demands multiplied by 2 5 for proposed
Day Spa
30,000
1,000
30,000
1,000
20 persons /day @ 50 gpd per person
(Year-round)
Proposed Pool
(Seasonal)
45,000
1,500 •
22,500
750
150 persons /day @ 10 gallons per person max
Average 200 people for 4 events / week at 3 gallons
Banqueting Facility
54,000
1,800
28,800
960
per person per meal (assumed 3 meals per day
served); Peak 7 events / week
Administration
14,400
480
4,560
152
All demands doubled for proposed
Subtotal - Inn &
444,728
48,158
1,044,720
34,824
Total peaks are estimated as the sum of individual
Associated Uses
peaks, which usually do not occur simultaneously
Maintenance
100,000
3,333
50,000
1,667
No increase from current
Residences
134
1,366,800
45,560
340
804,000
26,800
200
Total FIOW
2,911,528
97, 051
1,898,720
63,291
Total peaks are estimated as the sum of individual
peaks, which usually do not occur simultaneously
Peak Day
101,265
Peaking Factor of 160 % applied to average day
MUG TIMMnNS_
f DEMAND PROJECTIONS
2.2 IRRIGATION DEMANDS
2.2 IRRIGATION DEMANDS
In most domestic supply systems, residential irrigation comprises only a very small
part of the total demands. However, in exclusive subdivisions such as Keswick Estates,
irrigation demands can be quite significant. Dedicated irrigation metering and corresponding
separate billing records suggest a strong likelihood that this situation will prevail at Keswick.
Although only four irrigation meters were installed (among fifteen residences) before
February 2000, monthly irrigation -only demands had already exceeded 150,000 gallons
during three separate months significantly more than even the monthly domestic peak of all
fifteen residences.
Table 2-3: Current Dailv Water Consumption (with Irriaation)
Peak Month - aal
Der
A'vera a Month - cat Der
Location
Units
Notes
month
day
d-unit
month
QDd
I d-unit
Inn
48
380,000
12,667
293
286,500
9.550
284
Per Unit values based on 90% booking during Peak
Month and 70 % booking on Average
Clubhouse
111,000
3,700
66.950
2,232
Pavilion
42.500
1,417
15.600
520
Administration
7,200
240
2,290
76
Subtotal - Inn &
Peak Month total is based on highest month of
501,700
16, 723
371,340
12, 378
combined uses, and does not equal sum of peak
Associated Uses
individual uses.
Maintenance
100,000
3,333
50,000
1,667
These flows are currently unmetered, and are therefore
estimates only
Residences
12
122,240
4,075
340
71,406
2,380
200
Peak Month occurred with 12 residences filled;
Average over study period was 11 9 residences
Residential
4
161,630
5,388
1,347
Not Applicable
Irrigation
Peak Month total is based on highest month of
Total Flow
835,940
27,865
492,746
16,425
combined uses + oat maintenance demand, and does
not equal sum of peak individual uses.
Peak Day
26,280
Peaking Factor of 160% applied to average day; Peak
Day I Average Day of Peak Month = 108
Note: Table I data is extracted from water billing data for the period between July 1998 and February 2000, except as otherwise noted
TIMMONS
1 JW� DEMAND PROJECTIONS 2.2 IRRIGATION DEMANDS
Due to the absolute seasonality of irrigation demands, their addition into average
monthly flows does not produce a meaningful design criteria, as there is no readily
identifiable period during which even nearly average irrigation demands occur. Rather, peak
irrigation demands are added to peak domestic demands to determine total irrigation season
(May to September) demands. During the off-season (typically October to April), total
demands are not expected to significantly exceed average domestic -only demands.
Table 2-3 shows the addition of irrigation demands to Table 2-1, and identifies total
current monthly irrigation season demands as over 836,000 gallons.
The determination of future irrigation demands requires speculation as to the
propensity of future residents to significantly utilize in -ground irrigation systems. While it is
Keswick's goal to provide sufficient capacity to allow any and all residents to install and use
such systems, design to this end would likely result in a significantly oversized and
underutilized system, unnecessarily inflating its costs. Although only about 30% of existing
residents (four out of fifteen) use such systems, it is estimated that as many as two-thirds of
the buildout development's residents may ultimately use them, so irrigation demands are
applied to 89 out of a total 134 planned lots for demand estimates. In addition, the per -
connection average irrigation demand is significantly inflated by the unusually high
requirements of one of the existing residences evaluated (which during the irrigation season
demanded from 2'h to 6 times the average of the other three irrigated residences). These
factors result in a significantly conservative estimate of use. Table 2-4 shows the addition of
the resulting irrigation demand estimates to Table 2-2, and indicates total irrigation season
demands at over 6.5 million gallons. Due to the conservatism factors discussed above, and
since peak season irrigation demands will likely be spread out fairly evenly over the course
of any given peak season month, the average day of the peak month represents a fair estimate
of peak day demands, at about 217,000 gallons.
TIMMONS=
fff DEMAND PROJECTIONS
2.2 IRRIGATION DEMANDS
Table 2-4: Proiected Dailv Water Consumption (with Irriaation)
Peak Month - qal per
Avera a Month - qal per
Location
Units
Notes
month
day
d•unit
month
d
d•unit
Inn
76
601,236
20.041
293
485,640
16,188
284
Totals based on 90 % booking during Peak Month and
(targeted) 75 % booking on Average
Cottages
47
371,817
12.394
293
300,330
10,011
284
See note for Inn
Clubhouse
222,000
7,400
133.890
4,463
All demands doubled for proposed
Pavilion
106,275
3,543
39,000
1.300
All demands multiplied by 2.5 for proposed
Day Spa
30.000
1,000
30,000
1,000
20 persons / day @ 50 gpd per person
(Year-round)
Proposed Pool
45,000
1,500
22,500
750
150 persons / day @ 10 gallons per person max
(Seasonal)
Average 200 people for 4 events / week at 3 gallons
Banqueting Facility
54,000
1.800
28,800
960
per person per meal (assumed 3 meals pei day
served); Peak 7 events / week
Administration
14,400
480
4,560
152
All demands doubled for proposed
Subtotal - Inn &
1,444,728
48158
1,044,720
34824
Total peaks are estimated as the sum of individual
Associated Uses
,
,
peaks, which usually do not occur simultaneously
Maintenance
100.000
3,333
50,000
11667
No increase from Current
Residences 134
1,366,800
45,560
340
804,000
26,800
200
Residential
89
3,596,268
119,876
1,347
Not Applicable
Assumed that two-thirds of residences will regularly
Irrigation
use in -ground irrigation systems.
Peak Month total is based on highest month of
Total Flow
6,507,796
216,927
1,898,720
639291
combined uses, and does not equal sum of peak
individual uses.
• 49 TlM111nIV.ti'
EXISTING WATER SYSTEM
3.1 HISTORY
CHAPTER 3
EXISTING WATER SYSTEM
3.1 HISTORY
The Keswick Estate water system has matured over the years into a quality system for
delivering drinking water to the residents and guests. The original development of the
Country Club during the 1970's consisted of a water system that was located on the western
portion of the property. Multiple wells delivered water to a single tank located near the 17th
fairway to serve the Country Club.
Figure 3-1 - Supply Timeline
Western Eastern
Supply Supply
1970 1980
1990
Phase 1
Phase 2
Expansion
Expansion
Start
Start
1985
1991
2000
In the mid 1980's, the owner of the Country Club commissioned Roudabush, Greene
& Gale, Inc., to develop a plan for expanding the uses of the 500+ acre property. The
expansion included plans for adding homesites and additional buildings. As a part of this
work, Schnabel Engineering Associates was contracted to identify sources of drinking water
TIMMONS—
if EXISTING WATER SYSTEM 3.1 HISTORY
capable of meeting the increased demands of the development. In 1985, Schnabel presented
their findings, identifying two new well sites on the eastern edge of the property.
These wells would deliver the necessary quantity of water to meet the needs of the 26
farm lots, 80 clustered dwellings, and 44 single-family lots planned at the time. It was
decided to abandon the western water sources and tanks due to their unreliability and
detrimental effect on neighboring properties. A new well field was then created on the
eastern edge of the property in 1986. Supporting structures, including a well house, tanks,
and piping were added to deliver the water to the users.
A third well was added to the water supply system in December 1990, in anticipation
of expanding the system to include more homesites. This homesite expansion was started
towards the end of 1991. This second phase extended piping throughout the developed
portions of the property. This work was substantially complete by the end of 1992.
Construction of a new well house was begun in 1997. This was necessary due to a
failing foundation under the well house. This resulted in the treatment and storage facilities
moving across the road to their current location. At that time, several upgrades were made to
the system at the recommendation of Environmental System Service, Ltd. (ESS) in a report
prepared by them in 1994.
Photograph 3-1 Photograph 3-2
a..
Eastern Supply (Old)
Eastern Supply (Current)
3-2
` r, EXISTING WATER SYSTEM 3.2 SOURCES
In 1999, proposals were requested to complete a third phase of expansion of the water
system. Schematic alignments of the piping were developed by Roudabush, Gale and
Associates. However, due to the impending sale of the property to Orient -Express Hotels,
Inc., development and implementation of a third phase was abandoned.
Photograph 3-3
Wells No. 1 and 3
3.2 SOURCES
Well No. 2
Photograph 3-4
Keswick Estate has two distinct sources of water. Wells provide domestic supply,
while lakes furnish water to irrigate the golf course and grounds of the Inn. To understand
the source and quality of water from the wells it is important to understand the geology of the
Estate. There are two geologic formations located in the Keswick area. The majority of the
region is underlain by the Loudoun Formation (also known as the Candler Formation), while
an approximately 3,000-foot wide band known as the Everona Limestone Formation
traverses the region from southwest to northeast, encompassing the easternmost corner of the
Keswick Estate. Deep wells constructed within these formations draw water from fractures
• TIMMMV.
UEXISTING WATER SYSTEM 3.2 SOURCES
within the bedrock, which are recharged through the infiltration of rain into the overlying
soils or water from exposed bedrock fractures (as may occur in streambeds or elsewhere). In
limestone formations, fractures are typically more predominant and more transmissive than
in other types of formations. Over long periods of time, erosion in limestone from
groundwater flow can be expected to improve groundwater flow, while this does not
typically occur in other types of bedrock. The primary source of recharge in the Keswick
area is from the eastern slopes of the Blue Ridge Mountains to the northeast.
Four existing wells identified by Schnabel in 1985, which are located in the Everona,
have yields of 20, 42, 50, and 39 gallons per minute (gpm), respectively, or an average of 38
gpm. Nearby wells constructed in the Loudoun (36 identified in Report 1) have average
yields of only 6 gpm, with less than 15% exceeding a 10 gpm yield.
Well pump testing performed in 1985 and again in 1990 provided several evidences
of a significant supply of water in the Everona. As indicated above, yields of known existing
wells in the aquifer are quite good for the type of construction (rock well) and location
(Albemarle). In addition, pump test data demonstrated a steep but localized cone of
influence. During a continuous 72-hour pumping of the Keswick Well #3 in 1990,
drawdown in nearby (less than 500 feet away) Well #s 1 and 2 were recorded as no more
than 2.9 and 4.8 feet respectively, although water level fell 263 feet in #3. This is
demonstrated in Figure 3-4. Only 27 minutes after pumping ceased, #3's water level had
risen 235 feet, indicating readily available recharge water in the aquifer.
The work performed by Schnabel provides significant evidence that development of
additional wells in the Everona would impact only wells located within a small radius, and
that even those impacts would be minimal. Outside of Keswick Estates, the area's
development is anticipated to be confined to low density (large lot) residential uses. Since
such development requires only minimal well yields sparsely located, it is highly unlikely
that Keswick Estates would either impact or be impacted by additional development in the
area.
TIMMONS=
'M' EXISTING WATER SYSTEM
3.2 SOURCES
Figure 3-2 — Typical Cone of Influence
,.3A0o FED - I')
Cone of —
Influence
Keswick Estate Well
#2 (Loudoun)
The three wells on the Keswick property that are being used are located in the
southeast corner of the property. The permitted capacity of these wells is 73,520 gallons per
day. However, this could be increased to 82,300 gallons per day with the upgrade of the
pump in Well 93 to frilly utilize the well's safe yield capacity. Table 3-1 identifies the
characteristics of each well.
3-5
• TIMMONS=
1� EXISTING WATER SYSTEM
bz:.rrsr.-rra
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Table 3-1 — Well Characteristics
Well
Depth
Aquifer
Pump
Well
Motor
(Feet)
Rate
Yield
Size
(GPM)
(Safe)
(HP)
One
305
Everona
50.6
50.6
5
Two
247
Loudon
21
13.3
3/4
Three
305
Everona
28
39
3
4DT1,11,110lyi' 1
M` EXISTING WATER SYSTEM
3.3 SUPPLY INFRASTRUCTURE
The dependability of this system is adequate. Operations personnel observed the
pumping of brown water during the summer of 1999, which indicates that at least one of the
wells was reaching its capacity to deliver water to the system. However, this was observed
during an extreme summer drought.
Development of the Estate and Subdivision can continue to a significant extent
without improvements to the current system. The existing permitted capacity is sufficient to
supply average daily demands of up to 45,950 gallons (73,520 = 160%), which could
encompass all anticipated Estate expansion plus 47 residences. This is determined using
estimates of 34,824 gpd Estate demands plus 1,667 gpd Maintenance plus 47 residences @
200 gpd each equals 45,891 gpd. Upgrades of the existing system to fully utilize existing
well yields would allow average daily demands of up to 51,450 gallons (82,320 = 160%), or
all Estate development plus 74 residences. Additional well capacity would be required only
for the development of the remaining 60 residential lots.
3.3 SUPPLY INFRASTRUCTURE
Once the water enters the well house, sodium hypochlorite (a disinfectant), is added.
The watcr thcn flows into cithcr of two 18,000 gallon storagc tanks. Thcsc tanks arc locatcd
directly to the north of the well house. Each tank was cleaned and repainted in 1998 when
the well house was built. An alarm system was also installed to alert operations personnel to
problems while the facility is unstaffed. As water is demanded, it is taken from the 18,000
gallon storage tanks and pumped into a 6,000 gallon pressurized (hydropneumatic) tank.
Two pumps, Jacuzzi Model No. 20DB2-T, deliver about 200 gallons per minute to the
pressure tank to keep system pressures between 80 and 105 pounds per square inch. Figure
3-4 is a schematic of the water supply infrastructure.
3-7
10 TIMMONS-
Iff EXISTING WATER SYSTEM
3.4 DISTRIBUTION INFRASTRUCTURE
Figure 3-4 — Water System Schematic
Wells 18,000 gal pum s Pressure Tani
Storage p 6,000 gallons
Tanks
Add Sodium
Hypochlorite r`
18,000 gal
Storage Pumps
Tanks
3.4 DISTRIBUTION INFRASTRUCTURE
The Estate's distribution network consists primarily 6-inch polyvinyl chloride (PVC)
piping with 1-inch service taps to the homesite meter boxes. PVC is a typical piping material
that is economical and provides long lasting performance. Distributions systems that use
PVC are often inexpensive to modify and easy to maintain. Figure 3-5 generally outlines the
piping system that serves the Estate.
Distribution systems are usually designed as loops as shown in the figure. By looping
the system, several benefits are realized. First, it reduces the occurrence of pressure
fluctuations in the system. It also allows leaks to be isolated and repaired without disrupting
service to a large number of customers. Another benefit is to keep the water fresh, and
eliminate stale water from sitting in the pipe at dead ends, by keeping it circulating.
Em
• TIMMONS=
7= EXISTING WATER SYSTEM 3.4 DISTRIBUTION INFRASTRUCTURE
Figure 3-5 - Existing Water System
A comparison of the water production and billing records for Keswick between
August 1998 and March 2000 indicated average daily system losses of as much as 37,000
gallons per day. While this issue should continue to be monitored, recent discussions with
ESS personnel indicate that an open hose bibb was identified at the wastewater treatment
plant at the end of April 2000, and as of May 1st, water production has been reduced by
approximately 20,000 gallons per day. A portion of the remaining discrepancy between
� 7'1,ti1:11 �)1V ti
19 EXISTING WATER SYSTEM 3.4 DISTRIBUTION INFRASTRUCTURE
production and billing values is attributable to the golf course maintenance building and the
wastewater treatment plant, facilities whose demands are unmetered.
1I AD TIMMONS=
FR EXISTING WASTFWATFR SYSTEM
4.1 HISTORY
CHAPTER 4
EXISTING WASTEWATER SYSTEM
4.1 HISTORY
Design of the Keswick wastewater system was necessitated by the expansion of the
Estate's amenities during the late 1980's. It was decided to construct a central facility to
provide wastewater treatment and abandon the septic tank systems that were being used at
the time. Benefits of the central facility included elimination of odors and runoff from failing
septic tanks and drainfields. The system that exists today was developed over a four year
period. The treatment plant and first phase of the sanitary sewers were constructed in 1991.
The most recent additions to the system included service to the additional homesites along
Club Drive. Currently all the developed homesites have sanitary sewer service available.
Improvements will be required to serve additional homesites and the planned improvements
to Keswick Hall and its supporting amenities.
The Keswick Sewage Treatment Plant was constructed in 1991. The plant was
originally permitted to treat 60,000 gallons per day. Due to the low use of the facility's
permitted treatment capacity, the plant permit was reduced to 40,000 gallons per day. This
allowed a reduction in staffing and reporting requirements to the Virginia Department of
Environmental Quality (DEQ), resulting in significant cost savings to the plant's owners.
During the 20 month period between August 1998 and March 2000, the treatment plant's
average daily flow was 19,000 gallons. The original capacity of 60,000 gpd would be
available after re -permitting through DEQ.
4-1
TMMMON3
t�l i EXISTING WASTEWATER SYSTEM 4.2 COLLECTION SYSTEM
4.2 COLLECTION SYSTEM
Keswick's wastewater is collected by a network of gravity sewers conveying flow to
the treatment plant. As currently installed, the collection system requires very little
Figure 4-1 - Wastewater Collection System
Moff TI�I JWONS=
M EXISTING WASTEWATER SYSTEM
4.3 TREATMENT SYSTEM
maintenance or attention from Keswick maintenance staff. The system consists of
approximately 3.5 miles of 8-inch pipe, with an additional 3.2 miles already planned to serve
the ultimate buildout. Figure 4-1 illustrates the existing system.
4.3 TREATMENT SYSTEM
Constructed in 1991, the Keswick Estate treatment facility is an extended aeration
activated sludge plant. The plant was designed to treat 60,000 gallons per day of wastewater,
based on the expected uses shown in Table 4-1 below.
Table 4-1: Design Capacity Computations
Gallons per Gallons
Use Day
48
Guest Rooms
130
6,240
75
Seat Restaurant
50
3,750
100
Residential Lots
400
40,000
144
People at Golf Clubhouse
15
2,160
64
Seat Snack Bar
50
3,200
200
People at Swimming Pool
10
2,000
Total =
57,350
The extended aeration process is generally considered to be very reliable and
effective method of treatment for domestic wastewater. A basic schematic of the Keswick
STP is shown in Figure 4-2, including other treatment units that support the biological
treatment process, including a screening facility and a pump station that pumps the flows to
the top of the aeration tank to begin the biological treatment.
,, � TIMMONS=
Rl' EXISTING WASTEWATER SYSTEM
4.3 TREATMENT SYSTEM
Screening
and Pump
Station
Figure 4-2 Keswick STP Process Schematic
i� Post
Clarifier Aera
Aeration Tank Sand tion
Tank Filter
Aeration 1—� Clarifier 1—�
Sand
Tank Tank Filter
Creek
Photograph 4-1 shows the aeration tank, clarifiers and the digester. Photograph 4-2
shows the sand filter located inside the plant's filter building.
Photograph 4-1 Photograph 4-2
Aeration Tanks
Sand Filter
• TIMMONS- 1
�1 ij WATER FACILITIES PLAN
5.2 SOURCE OPTIONS
CHAPTER 5
WATER FACILITIES PLAN
5.1 GENERAL
The buildout domestic and irrigation demands of the Keswick Estate and Subdivision
will require additional water system infrastructure. Furthermore, the minimal level of fire
protection currently provided throughout the existing system merits discussion of related
infrastructure improvements. This Chapter addresses those needs, including supply, storage
and pumping, and linework. Where options are available, the implications, requirements,
and critical cost components of each are presented, with recommendations made at the end of
the Chapter. Total costs (in year 2000 dollars) of each suitable combination of alternatives
are included in Section 5.5.
5.2 SOURCE OPTIONS
5.2.1 WELLS -ONLY SUPPLY
The existing supply of three wells with a permitted capacity of 73,520 gallons per day
(gpd) will not be sufficient to meet even the ultimate domestic -only peak day demands of
101,265 gpd. Although minor modifications to one of the three well pumps would increase
available source supply, an additional well would still be required to raise permitted capacity
to meet projected domestic demands.
5-1
TIMMONS=
tiij WATER FACILITIES PLAN 5.2 SOURCE OPTIONS
The permittable capacity of well supplies in terms of daily demands is governed by
the Virginia Department of Health's (VDH) Waterworks Regulations. Essentially, those
Regulations require one gallon per minute (gpm) of well yield for every 800 gallons per day
of water to be supplied. For domestic -only demands (peak month) of 101,265, a total well
yield of 127 gpm is required, 35 gpm greater than currently available. This deficit could be
reduced to 24 gpm with the upgrade of Well #3's pump, but would still require an additional
well. With the addition of residential irrigation demands (for a total demand of about
217,000 gpd), a total well yield of 272 gpm would be required, 180 gpm greater than
currently available.
According to Environmental Systems Services (ESS), a fourth well has previously
been planned in the area immediately surrounding the existing pump house near Route 616.
However, no specific action has been taken regarding its construction. It is believed that the
minimal 30 gpm yield required of a fourth well for ultimate domestic demands would be
readily achievable, and it's impacts on the existing Estate wells would likely be insignificant.
The same is not true for the wells required to meet irrigation and domestic demands
combined. In reports prepared between 1985 and 1991 by Schnabel Engineering, four wells
in the Everona Limestone formation were identified, averaging a yield of 38 gpm. Assuming
new wells in the vicinity of Keswick would yield similar flows, five additional wells would
be required. Due to the limited extent of the high -yielding Everona Limestone aquifer on
Keswick property, a well field including eight wells (three existing plus five additional)
would be very compact and would likely have a significantly reduced per -well yield, as each
well would exert a significant drawdown influence on the others.
The necessary additional yield may be attainable using the full width of the Everona
Limestone band. Therefore, the best -advised expansion of the existing well field to meet
irrigation demands would be expansion across, or perpendicular to the aquifer. As the
Estate's wells currently span the entire portion of the aquifer located on Estate property,
purchase of and expansion onto property to the east or southeast not currently owned by the
Estate would be recommended, where significant additional yields (similar to those of the
5-2
Tom' WATER FACILITIES PLAN 5.2 SOURCE OPTIONS
existing Well #s 1 and 3) could be anticipated. Further subsurface analysis of the aquifer
would be required to confirm this, including test drilling and pump testing. The cost of
construction of new wells meeting the requirements of VDH for public water supply is
estimated at $25,000 each. Figure 5-1 illustrates the portions of the limestone band both
within and outside of Estate property.
Figure 5-1 — Everona Limestone Location
L
te ar'
o�
VV
0
TIN irf
The primary drawback to well supplies is reliability, particularly during drought
conditions. As indicated in Chapter 3, the Keswick wells were significantly impacted during
the drought of 1999 (even though they marginally maintained adequate supply), and the same
can be expected during future such events. While admittedly rare, these events must be taken
into account when evaluating the necessity for a reliable source of supply. If wells are to be
used for irrigation supply, it would be advisable to implement and strictly enforce a plan for
water conservation during severe dry spells.
5-3
TIMMONS=
WATER FACILITIES PLAN
5.2 SOURCE OPTIONS
5.2.2 POND -SUPPLIED IRRIGATION
As an alternative to continued use of wells for residential in -ground irrigation system
demands, the existing ponds on Carroll Creek could feed a separated irrigation -only system
distributing a non -potable water supply throughout the subdivision. Daily residential
irrigation demands estimated in Chapter 2 (Table 2-4) total approximately 120,000 gallons,
which is more than one-third of the total used in -season for irrigation of the golf course.
Mitigation of this significant impact on golf course irrigation supply would be necessary
during very dry seasonsl, and could be at least partially accomplished by supplementing with
the wastewater treatment plant's treated effluent. Since average projected domestic water
demands (the volume of which will be reflected in the wastewater plant's effluent flow) total
approximately 63,000 gallons per day, only this amount of augmentation of the golf course
irrigation supply could be planned. Given the worst case residential irrigation demand of
approximately 120,000 gallons, the worst case net impact on irrigation supply would be
57,000 gallons per day. However, the conservatism factors included in the irrigation demand
calculations of Chapter 2 suggest that the actual impact would be much less, possibly even
netting out to a benefit.
So-called re -use supply for irrigation demands, even for areas with free public access,
is more common in western portions of the IJnited States than in Virginia. However, there
are a significant number of existing and planned re -use applications in the Commonwealth
for irrigation of golf courses and other non-public areas, and VDH has established criteria
through a "working memorandum" for their design and operation. Specific bacteriological
effluent quality standards apply, depending upon the level of treatment at the wastewater
plant and dilution at the irrigation supply. Discharge into one of the ponds a significant
distance upstream from the golf course irrigation withdrawal point would lessen the
restrictions on treatment and operation. In addition, particular attention must be paid to the
application of potentially nutrient -rich wastewater effluent to golf course grasses. However,
Keswick's current Golf Course Superintendent is experienced with wastewater reuse.
E[IFT-IMMONSL-7
`�'1T ; WATER FACILITIES PLAN 5.3 STORAGE & PUMPING
Since wastewater effluent irrigation of golf courses, but not of residential properties,
is accepted practice in the Commonwealth such a residential irrigation system should be
supplied from a point upstream of the discharge of wastewater. At Keswick, this could be
accomplished by pumping treated effluent to the head of Paradise Lake, which supplies a
golf course irrigation supply pump station. Supply for the residential irrigation system could
be withdrawn from Lake Broadmoor, upstream of the wastewater discharge.
The greatest potential drawback to a separated pond -fed residential irrigation supply
would be cost. A certain level of treatment would be advisable for the irrigation supply,
consisting primarily of filtration to remove sediments or solids which may damage or reduce
the life of irrigation system components. Following this treatment, pressurized storage and a
separate distribution system throughout the subdivision would be necessary. Therein lies the
greatest cost, as approximately five miles of separate irrigation -only waterline would be
required. Construction costs of a new six-inch diameter network of mains is estimated at
approximately $650,000. However, an option including upgrade of certain portions of the
existing potable distribution system is discussed in Section 5.4, which if selected would
significantly reduce this cost by enabling the conversion of already -constructed waterlines to
irrigation -only use.
5.3 STORAGE & PUMPING
Although the well pump rates are currently the limiting factor for the system's
capacity, storage and booster pumping capacities are only slightly higher. With projected
ultimate peak day domestic consumption at 101,265 gpd, upgrade to these components will
be required as well.
Based on the Regulations, storage and pumping requirements are established by
simple calculations. Storage must be equivalent to 50% of design capacity, and pumping
capacity (from non -pressurized storage into the distribution system) is based on the formula:
0 TI.MMONS
Fff" WATER FACILITIES PLAN
5.3 STORAGE & PUMPING
Pump Rate = (11.4) (Design Capacity / 400) 0.544
For the 101,265 gpd design capacity, a minimum of approximately 51,000 gallons of storage
must be provided, and pumping capacity must be at least 232 gpm. To meet these
requirements, an additional 13,000 gallons of non -pressurized storage must be provided, and
the existing 200 gpm booster pumps must be upgraded. Estimated construction costs for
these improvements would not be expected to exceed $30,000.
If residential irrigation demands are also supplied from the system, a permitted
capacity of 217,000 gpd will be required in order to satisfy VDH criteria. The result would
be the addition of 70,500 gallons of non -pressurized storage (for a total of 108,500 gallons),
and upgrade of the booster pumps to 351 gallons per minute. Estimated construction costs
for these upgrades may approach $100,000.
However, the above discussion does not address fire protection supply. In many
municipalities, design requirements for subdivisions served by a public water system include
a minimum 1,000 gpm available fire flow, which provides excellent property and life
protection, and can result in reduced insurance premiums. In order to meet this demand for
an extended period of time, either adequate booster pump capacity, or pressurized or elevated
(water tower) storage must be provided. If this issue is to be addressed at Keswick by
pumping, a separate 1,000 gpm fire service pump (at a construction cost of $50,000 to
$75,000) could be provided in addition to the upgrade of the existing pumps for domestic
service. Elevated or pressurized storage of at least 70,500 gallons, strategically located
within Estate property, would simultaneously address additional storage and pumping needs
for domestic, residential irrigation, and fire flow demands. Depending on location,
construction cost of an elevated tank would range from $275,000 to $450,000, with a higher
tank site favoring lower cost of construction. Pressurized storage of 70,500 gallons could
carry costs similar to the middle to upper range of an elevated tank, and would require a
larger parcel of land and additional mechanical components. These issues must be balanced
with aesthetic concerns.
T / MMONS=
Iff` WATER FACILITIES PLAN 5.4 LINEWORK
5.4 LINEWORK
Linework limitations at Keswick are primarily related to fire protection. Even with
residential irrigation demands being met through the existing 6-inch and 4-inch diameter
piping network, normal system pressures can easily be maintained above 40 psi at the highest
and most remote point — the Inn itself. However, no more than 500 to 600 gpm can be
supplied to the most remote (northernmost) residential lots without reducing residual
pressure at the Inn to below 20 psi, the lowest design value allowed by the VDH Regulations.
A typical 6-inch waterline carrying 1,000 gpm will lose over 35 psi of pressure for
every 1,000 feet of line due to pipe friction, assuming elevation differences are negligible.
For this reason, dead-end 6-inch mains are rarely extended further than 1,000 feet when
considering fire protection. In looped systems where one-half of the fire demand can be met
from each of two directions, a friction loss of only 10 psi per 1,000 feet occurs. Smaller
mains are generally unsuitable for these demands and as such, the 1,800 linear feet of 4-inch
water main along Fairway Drive between Club Drive and Paradise Lake is recommended for
replacement.
To determine the necessary upgrades to provide the desired level of fire protection, a
computer model of the system was prepared, including the addition of the previously
proposed (by Roudabush & Gale) 8-inch waterline through the yet undeveloped eastern
portion of the Estate, and the replacement of the Fairway Drive waterline (mentioned above)
with 8-inch line. Various combinations of upgrades were then modeled in order to determine
the least -cost approach. The result was the replacement of the Club Drive waterline, with 10-
inch diameter line between the source and its southern intersection with Fairway Drive, and
with 8-inch diameter line from there to the Inn, as illustrated in Figure 5-2. Total
construction cost of this Club Drive waterline replacement is estimated at $300,000.
However, if a separated irrigation supply is provided, this alternative would make available
13/4 miles of the existing 6-inch distribution system for non -potable uses, saving over
$200,000 of the costs of that system.
• TIMMONS=
�� WATER FACILITIES PLAN
5.4 LINEWORK
One significant factor contributing to the system's current inability to meet the
desired demands is the elevation differences between the existing supply and more
importantly, the existing pumps and pressurized storage. Elevations at the pump house are
sixty or more feet below those at the Inn. This alone results in a 26 psi pressure differential
between the two locations, which is added to any pipe friction losses. Locating pumping
and/or storage in the higher northern portion of the Estate would result in elevational
Figure 5-2 — Club Drive Waterline Replacement Alternative
Inn
Upgrade
611 to 811
upgrade
6"toSol
Waterlines
Existing
Future -----
upgrade
Scale in Miles
S 1/4 1/2
North
Upgrade
4" to S"
611
p
6„ ° 1`
\ 11
I�
\upgrade
6" to 1 on
Well Field
TIMMV
Ift` WATER FACILITIES PLAN 5.5 SUMMARY & RECOMMENDATIONS
differences offsetting a significant portion of friction losses associated with fire flows, and
would reduce required line sizes. In fact, beyond the future 8-inch waterline addition and the
replacement of the 1,800-foot length of 4-inch Fairway Drive waterline, no distribution
system upgrades would be required.
5.5 SUMMARY & RECOMMENDATIONS
In summary, there are a variety of infrastructure combinations that would meet
Keswick's future demands. A supply alternative must be selected to meet domestic and
irrigation demands. The provision of 1,000 gpm fire flows throughout the Estate and
Subdivision would require additional infrastructure.
The combinations presented herein are listed below, with approximate total
construction costs. Supply alternatives do not in themselves provide sufficient (1,000 gpm)
fire protection. Fire Protection alternatives include both recommended supply system
coupled with additional infrastructure to meet 1,000 gpm fire demands. Regardless of the
alternative selected, both the future addition of an 8-inch waterline in the yet undeveloped
portion of the subdivision, and the replacement of the 1,800-foot length of Fairway Drive
waterline are recommended. Based on the anticipated alignment of the future waterline, its
construction cost is estimated at $150,000. Construction of the Fairway Drive waterline
replacement could be expected to cost approximately $60,000. A line item for these costs is
included in the construction costs for the alternatives that follow.
5-9
'I�' WATER FACILITIES PLAN
5.5 SUMMARY & RECOMMENDATIONS
5.5.1 SUPPLY (DOMESTIC AND IRRIGATION) ALTERNATIVES
Alternative S-1: Well -Supplied
• Source: Five new wells...................................5 @ $25,000 ........ $125,000
• Storage: 70,500 gallons .......................................... $90,000 .......... $90,000
• Pumping: Upgrade 200 to 351 gpm.................2 @ $10,000.......... $20,000
• Linework: 4-inch from expanded wellfield ............ $35,000 .......... $35,000
• Linework: Future 8-inch and Upgrade 4-inch ...... $210,000........ $210,000
TOTAL CONSTRUCTION COST ......................................................... $480,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (15%)....... $70,000
TOTAL PROJECT COSTS*............................................................. $550,000
* Does not include the cost of purchasing additional wellfield property
Alternative S-2: Pond -Supplied Irrigation
• Domestic Source: One new well ..................... I @ $25,000 .......... $25,000
• Dom. Storage: 13,000 gallons ................................ $20,000 ..........
$20,000
• Dom. Pumping: Upgrade 200 to 232 gpm......... 2 @ $5,000 ..........
$10,000
• Dom. Linework: 2-inch from fourth well ................. $5,000............
$5,000
• Dom. Linework: Future 8-inch, Upgrade 4-inch..
$210,000 ........
$210,000
• Irrigation Treatment: Filtration System ..................
$80,000..........
$80,000
• Irrig. Storage: 10,000 gallons pressurized .............. $30,000..........
$30,000
• Irrig. Pumping: Dual pumps ............................2 @ $25,000 ..........
$50,000
• Irrig. Linework: 6-inch network ........................... $650,000 ........ $650,000
TOTAL CONSTRUCTION COST ......................................................
$1,080,000
ADD ENGINEERING. ADMINISTRATIVE & CONTINGENCIES (15 %)
..... $160,000
TOTAL PROJECT COSTS*.......................................................... $1,240,000
* Does not include the costs associated with augmenting golf course irrigation supply
with wastewater treatment plant effluent.
Clearly, the provision of irrigation supply through the existing well system is the most
cost-effective method of supply. The conversion of the existing 6-inch Club Drive and 4-
inch Fairway Drive waterlines to non -potable use would reduce Alternative S-2's
construction costs by approximately $235,000, but would still leave a $430,000 project cost
differential between the two alternatives. In addition, a well supply permits the gradual
expenditure of the most costly item of construction - the wells themselves. As demands
5-10
`R[-" WATER FACILITIES PLAN
5.5 SUMMARY & RECOMMENDATIONS
increase, additional wells may be added to meet them. If irrigation demands never reach the
conservative values estimated in Chapter 2, fewer wells may ultimately be required, further
reducing the Alternative's costs.
5.5.2 FIRE PROTECTION ALTERNATIVES
Alternative F-1: Fire Pump at Existing Pump House
• Pumping: 1,000 gpm fire service ............................ $75,000 .......... $75,000
• Linework: Upgrade Club Drive waterline ............ $300,000 ........ $300,000
• Alternative S-1: Well Supply ................................ $480,000 ........ $480,000
TOTAL CONSTRUCTION COST ......................................................... $855,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (15%)..... $130,000
TOTAL PROJECT COSTS............................................................... $985,000
Alternative F-2: Northern Fire Pump with Storage
• Pumping: 1,000 gpm fire service ............................ $75,000 .......... $75,000
• Storage: Northern 70,500 gallons ................... (incl. in S-1)................... $0
• Storage: Northern 6,000 gallons pressurized.......... $20,000 .......... $20,000
• Northern Domestic Pumping: Dual Units ........ 2 @ $30,000 .......... $60,000
• Alte, native .S-1: Well Supply ................................ $480,000 ........ $480,000
TOTAL CONSTRUCTION COST ......................................................... $635,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (15%)....... $95,000
TOTAL PROJECT COSTS............................................................... $730,000
TIMMONS=
ff.' WATER FACILITIES PLAN 5.5 SUMMARY & RECOMMENDATIONS
Alternative F-3: Northern Elevated or Pressurized Storage
• Pressure or Elevated Storage: 70,500 gallons....... $375,000 ........ $375,000
• Alternative S-1: Well Supply ................................ $480,000 ........ $480,000
• Less Storage: 70,500 gallons ............................ $90,000.......... $90,000
• Less Pumping: Upgrade 200 to 351 gpm... 2 a, $10,000 .........-$20,000
TOTAL CONSTRUCTION COST ......................................................... $745,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (15%)..... $1 10,000
TOTAL PROJECT COSTS............................................................... $855,000
Between Alternatives F-2 and F-3, the $125,000 savings (17% of the lower estimate)
is significant however, the increased operation costs associated with the less expensive
capital project must be considered. A non -pressurized 70,500 gallon supply would be
located adjacent to the northern fire pump, in order to supply sufficient water to manage
extended duration fire events. This non -pressurized supply would be fed from the already -
pressurized distribution system. Returning this water back into the system would require re -
pumping, thereby increasing energy costs by an estimated $3,000 per year. In addition, this
system would contain five pumps (two southern and two northern domestic supply pumps,
and one fire pump), versus only two for Alternative F-3, resulting in added regular
maintenance and repair costs. Most significantly, elevated or pressurized storage would
provide a reliable supply for all types of demands that would not depend upon significant
electrical or mechanical components.
5.5.3 CONCLUSION
The types and magnitude of future water demands at Keswick will require additional
supply, storage and/or pumping capacity, and linework additions and upgrades. In order to
permit the most cost-effective approach to meeting supply requirements, purchase of
additional property overlying the Everona Limestone formation is recommended. This will
I We TIMMONS
I ij WATER FACILITIES PLAN
5.5 SUMMARY & RECOMMENDATIONS
permit the continued and incremental expansion of the existing well field as demands
increase.
Rather than significantly upgrading linework to provide adequate (1,000 gpm)
fireflow throughout the system, additional storage requirements of 70,500 gallons should be
provided on the north end of the system. Elevating or pressurizing this storage will eliminate
the need for additional pumping, but aesthetic concerns must be evaluated.
As future development occurs, new waterlines should be constructed to permit
adequate (1,000 gpm) fireflow to all areas, which will generally require 8-inch diameter
lines. For the same reason, the existing length of 4-inch waterline on Fairway Drive should
be upgraded to 8-inch.
' Discussions with Keswick's Golf Course Superintendent indicate that during 1999's drought, a reduction in
golf course irrigation frequency was required to maintain adequate supply, even without any residential use of
the existing ponds. A complete watershed hydrology analysis, which is beyond the scope of this study, would
be required to exactly determine the effects of residential property irrigation from the golf course irrigation
supply.
NOVA TIMMONS=
1
WASTEWATER FACILITIES PLAN 6.1 TREATMENT
CHAPTER 6
WASTEWATER F+'ACILITIES PLAN
6.1 TREATMENT
Wastewater treatment capacity is typically selected to meet average demands, as
permitting and effluent requirements are primarily based on monthly averages. At Keswick
however, the significant seasonality of water use associated with Inn operations requires
capacity to meet peak month demands. Wastewater treatment facilities must also be
designed to continually operate at not more than 95% of design capacity, since three
consecutive months of operation above this value triggers the Department of Environmental
Quality's (DEQ) requirement for a compliance action plan. Therefore, based on peak month
demands of approximately 101,265 gallons (from Table 2-2), a capacity of not less than
110,000 gallons per day (gpd) is recommended. An additional factor of safety is provided in
this recommendation, as peak month water demand estimates also include residential
irrigation (for those residents without separate irrigation meters), which is not returned to the
sewers.
The existing 60,000 gpd wastewater treatment facility is configured as a dual "train"
30,000 gpd plant, with biological treatment cells, clarifiers, filters, and sludge storage all
duplicated. To expand the plant to a 110,000 gpd capacity, a third train at 50,000 gpd
capacity could be provided by the addition of another biological treatment cell, clarifier,
filter, and sludge holding basin. The expansion would also require the upgrade of the
unduplicated components of the existing system, including the influent headworks and
pumping station, and the ultraviolet disinfection system. While the plant was not originally
designed for such an upgrade, the site is adequately sized (although not ideal) to support the
necessary expansion.
6-1
ff WASTEWATER FACILITIES PLAN 6.2 UNEWORK
Permitting for an expanded capacity is currently under way. ESS has recently
submitted to DEQ a renewal application for the plant's Virginia Pollutant Discharge
Elimination System (VPDES) permit, and has requested tiered permitting for a capacity up to
100,000 gpd. Although exact effluent limits will not be known until after the permit is
issued, it is anticipated that the existing treatment process will be capable of achieving the
new effluent limits.
6.2 LINEWORK
Required capacity for sewers is based on peak hour flows. For small flows (less than
a million gallons per day MGD), the peak hour condition is commonly determined from the
calculation:
Required Capacity in MGD = (3.5) (Average Daily Flow in MGD) 0,807
For Keswick's average daily flows of 63,291 gpd or 0.063 MGD (from Table 2-2), a required
capacity of 0.38 MGD is calculated. If, as with treatment capacity, it is assumed that
projected peak month flows will represent a summer's average month, the 101,265 gpd (or
0.101 MGD) average results in a required capacity of 0.55 MGD. These flows will occur in
the trunk sewers leading directly to the treatment facility, while lower flows will occur in
branch lines.
The existing sewers at Keswick are generally 8-inch diameter, the minimum required
by the Virginia Department of Health (VDH). Installed at the minimum slope allowed by
VDH, 8-inch lines are capable of carrying at least 0.54 MGD. At slightly steeper slopes
(such as that of the "trunk" sewers leading directly to the existing wastewater plant), 8-inch
lines are easily capable of carrying the maximum total peak flows anticipated. Therefore, all
sewer lines in the Keswick collection system are adequate for the projected flows.
6-2
TIMMONS=
WASTEWATER FACILITIES PLAN 6.2 LINEWORK
As with water system development, future expansion of the sewer collection system
will be required as the currently undeveloped eastern portions of the subdivision are opened.
Also as with the water system, Roudabush and Gale have previously proposed alignments for
the future sewers. Figure 6.2 illustrates these alignments, which total approximately 17,000
linear feet.
Figure 6-2 — Future Collection System Development
40'I'1"wr19OXs
WASTEWATER FACILITIES PLAN
6.3 SUMMARY & RECOMMENDATIONS
6.3 SUMMARY & RECOMMENDATIONS
The existing wastewater collection and treatment system is readily expandable to
meet the required ultimate demands of the Estate. A parallel 50,000 gpd treatment train can
be constructed on the facility's existing site, along with upgrades to the undersized
headworks and final treatment components.
Existing collection system linework is already sized sufficiently to carry ultimate
peak flows. Continued expansion of the system to meet minimum standards of VDH will
automatically guarantee sufficient capacity in future development areas.
Costs of future upgrades (in year 2000 dollars) are estimated as follows:
• Treatment: Add 50,000 gpd train ................................................. $350,000
• Headworks: Upgrade for 110,000 gpd capacity ............................. $80,000
• Final Treatment: Upgrade for 110,000 gpd capacity ......................$50,000
• Linework: Future 8-inch sewers ................................................... $550,000
TOTAL CONSTRUCTION COST ...................................................... $1,030,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (15%)..... $155,000
TOTAL PROJECT COSTS............................................................ $1,185,000
TIMMONS=
TABLE OF CONTENTS
APPENDIX C
WATER FACILITIES PLAN 2007 UPDATE - NOVEMBER 2, 2007
TIMMONS GROUP
WATER FACILITIES PLAN
2007 UPDATE
For
KESWICK ESTATES
& SUBDIVISION
November 2, 2007
Prepared by
•'
TIMMONS GROUP .•:'•.
WATER FACILITIES PLAN
2007 UPDATE
For
KESWICK ESTATES
& SUBDIVISION
Oi
WESLEY G.
HUNNIUS
Lic. No. 040151
QUALITY ASSURANCE
STATEMENT
A Quality Control and Assurance review has
been performed on this document in accord-
ance with the TIMMONS Quality Plan. The
undersigned states that this document has
been checked and reviewed in a manner
commensurate with the level of detail
for the type of submittal indicated below.
Wes Hunnius
Pro/ecl Manager
11 /2/07
Wb
Prepared By: Checked By: Reviewed By:
WGH WGH WGH
November 2, 2007
Prepared by
•
TIMMONS GROUP .•
'�••.
TABLE OF CONTENTS
TABLE OF CONTENTS
CHAPTER 1 — INTRODUCTION
ULIPurpose................................................................
U1.2 Scope...................................................................
CHAPTER 2 — DEMAND PROJECTIONS
....................................
....................................
U2.1 Domestic Demands..............................................................................................2-1
U2.2 Irrigation Demands.............................................................................................. 2-1
Table U2-3: Current Daily Water Consumption (with Irrigation)
Table U24: Projected Daily Water Consumption (with Irrigation)
CHAPTER 5 — WATER FACILITIES PLAN
U5.1 General................................................................................................................. 5-1
U5.2 Source Options.....................................................................................................5-1
U5.2.1 Wells -Only Supply
U5.3 Storage & Pumping..............................................................................................5-2
U5.5 Summary & Recommendations...........................................................................5-3
U5.5.1 Supply (Domestic Including Existing Irrigation)
U5.5.2 Fire Protection Alternatives
U5.5.3 Retrofitting Existing System
U5.5.4 Conclusion
TOC-1 TIMMONS GROUP.--*;;*-.
INTRODUCTION
CHAPTER 1
INTRODUCTION - UPDATE
U1.1 PURPOSE
CHAPTER 1
It has been several years since the completion of the last Water and Wastewater
Facilities Plan. Changes have continued to occur in the existing and proposed water
infrastructure and demands at Keswick Estate since the preparation of the Water and
Wastewater Facilities Plan (Plan), prepared by Timmons Group in November 2000 and the
subsequent updates completed in 2004 and 2005. As additional phases of development are
currently being constructed and planned, specific plans need to be made regarding the supply
and fire suppression alternatives to be employed. The 2000 Plan presented various
alternatives for domestic and fire suppression supply through buildout development. With
the changes in the supply (contamination and subsequent closing of Well # 3 and addition of
Well # 4), the alternatives presented require review. Additionally, fire suppression remains a
primary goal for the future of the Estate. It is understood that the fire storage system is
planned to be located adjacent to the Energy Center, on the Hunt Club Side. This Update
will evaluate the pressurized and non -pressurized (ground) storage for the fire suppression
system relative to capitol and future maintenance costs.
U1.2 SCOPE
The scope of this Study is as follows:
• Re-evaluate existing and proposed demands and based on them, provide updated
estimates of future capacity requirements for the water system.
• Re-examine the existing water system to determine deficiencies, if any, as related
to their ability to meet the projected ultimate demands.
1-1 TIMMONS GROUP .--*;;*.
INTRODUCTION
CHAPTER 1
• Re-evaluate alternatives for upgrade or additions to the existing water system to
meet projected ultimate demands, and make recommendations.
• Re-evaluate fire suppression alternatives to meet projected needs and make
recommendations.
• Provide updated cost estimates for the recommended upgrades and additions.
1-2 TIMMONS GROUP .-"Z*.
lff t DEMAND PROJECTIONS - UPDATE CHAPTER 2
CHAPTER 2
DEMAND PROJECTIONS - UPDATE
U2.1 DOMESTIC DEMANDS
For the January 2001 through July 2004 period previously analyzed the average
domestic use water billings totaled approximately 475,000 gallons per month which
increased approximately 7% from the numbers used in the 2000 study. As in the original
study, another 50,000 gallons per month is estimated for unmetered (and therefore unbilled)
demands at the golf course maintenance and wastewater treatment facilities, for a total of
approximately 525,000 gallons per month. Based on the new data, the average daily
(domestic only) demand is therefore estimated at 17,467 gallons per day (gpd) which is up
slightly from the 16,425 gpd in the 2000 study. This increase can be attributed to an increase
in use at the Clubhouse, Pavilion, Administration and the addition of the Pool and Staff
Housing. The average domestic usage for the Inn and Residences has decreased. These
numbers are listed under Average Month in Table U2-3.
U2.2 IRRIGATION DEMANDS
Since the 2000 study, Keswick has made several changes to the irrigation policy as it
relates to irrigation at the Inn and individual residences. First, the supply for the Inn
irrigation system has been switched from the domestic water system to the surface water
supply system used to irrigate the golf course. Second, new irrigation systems are no longer
allowed at individual residences with the exception of drip irrigation on flower beds, which
represents a small demand. The five residential irrigation meters which existed prior to this
change in policy have been allowed to remain, however all residents have been asked to
reduce water use for irrigation.
This change in the irrigation policy has had a significant effect on the daily water
consumption throughout the typical irrigation season (May to September). The Inn has seen
2-1 TIMMONS GROUP . ':'•.
DEMAND PROJECTIONS - UPDATE CHAPTER 2
a reduction of approximately 50,000 gallons per month and individual residences with
irrigation systems have also seen a decrease in usage for irrigation. However, the switch to
surface water irrigation for the Inn represents a permanent reduction while at least a portion
of the decrease in residential irrigation use is attributable to better than average rainfall since
2002.
Table U2-3 summarizes the analysis for existing demands, including irrigation, based
on the January 2001 through July 2004 period analyzed.
Table U2-3: Dailv Water Consumntion (with Irrigation)
Location
Units
Peak Month
- al r
Avera a Month - al r
Notes
month
dayd-unit
month
d
d-unit
Inn
48
390,000
13,000
301
270,000
9,000
268
Per Unit values based on 90% booking during Peak
Month and 70 % booking on Average
Clubhouse
136,000
4,533
75,000
2,500
Pavilion
107,400
3,580
20,000
667
Administration
8,300
277
4,200
140
Pool
35,170
1,172
11,000
367
Staff Housing
18,650
622
14,500
483
Subtotal - Inn &
Peak Month total is based on highest month of
Associated USES
695,520
23,164
394,7I10
13,157
combined uses, and does not equal sum of peak
individual uses.
Maintenance
100,000
3,333
50,000
1,667
These flows are currently unmetered, and are lherelor
estimates only
Residences
14
121,380
4,186
299
79,321
2,644
1 182
Peak Month occurred over a 29 day period with 14
residences filled; Average over study period was 14.5
residences
Residential
Irrigation
5
185,730
6,191
1,238
Not Applicable
Based on 5 irrigation meters
Peak Month total is based on highest month of
Total Flow
907,730
30,258
524,021
17,467
combined uses + cal. maintenance demand, and does
not equal sum of peak individual uses
Peak Day
27,948
Peaking Factor of 160% applied to average day
rvorer r gore oara rs e+naueo rrom warer owuny uma ror m penoa oerween jarwaryeuur ano jury zuu4, except as olnenvtae noted.
Due to the absolute seasonality of irrigation demands, their addition to average
monthly flows does not produce a meaningful design criteria, as there is no readily
identifiable period during which even nearly average irrigation demands occur. Rather, peak
irrigation demands are added to peak domestic demands to determine total irrigation season
2-2 TIMMONS GROUP .•'':'%
V DEMAND PROJECTIONS - UPDATE CHAPTER 2
demands. During the off-season (typically October to April), total demands are not expected
to significantly exceed average domestic -only demands.
At the time the 2000 study was completed it was assumed that as many as two-thirds
of the buildout development's residents may ultimately use residential irrigation systems.
With the change in the irrigation policy, there has been a significant change in that
projection. If no new residential irrigation systems are allowed, the only residential irrigation
demand will come from the five existing irrigation meters and will not represent a large
demand in the overall development.
As in the 2000 study, projections for future demands were evaluated based on unit
values determined from Table U2-3 applied to buildout development plans. The resulting
demand estimates are provided in Table U2-4. Despite a small decrease in domestic use (182
gpd vs. 200 gpd in 2000) from residences as shown in Table U2-3, 200 gpd is used to project
domestic demands in Table U2-4 since it is a more realistic factor for the long term.
Similarly, despite a decrease in domestic irrigation use (1238 gpd vs. 1347 gpd in 2000), the
original number is used in Table U2-4 since it is likely more realistic for the long term.
One significant change included in this update is the projected decrease in the
domestic demands at the golf course maintenance and wastewater treatment facilities.
Currently there are plans to utilize clean effluent water from the wastewater treatment facility
for non potable uses at both the golf course maintenance and wastewater treatment facilities.
This "reuse" of water will result in a significant decrease in the amount of water used and
therefore the projected average demand has been decreased to 10,000 gallons per month.
As shown in Table U2-4, total irrigation season demands of 3.0 million gallons per
month with the average day of the peak month at about 99,785 gallons are projected for
buildout. The 2000 projections, which included 89 residential irrigation meters, were 6.5
million gallons per month with the average day of the peak month estimated at 217,000
gallons. As compared to the 2000 domestic -only projections (just over 2.9 million gallons
per month) the new total projections, which include the five existing irrigation meters, are
essentially equal.
2-3 TIMMONS GROUP .--*;;*.
DEMAND PROJECTIONS - UPDATE
Table 2-4: Proiected Dailv Water Consumption (with Irrigation)
CHAPTER 2
Peak Month
- gal per
Avera a Month • a! er
Location
Units
Notes
month
day
d•unit
month
gpd
I d•unit
Inn
48
390,096
13,003
301
289,440
9,648
2gg
Totals based on 90% booking during Peak Month and
(targeted) 75 % booking on Average
Cottages
75
609,525
20,318
301
452,250
15,075
268
See note for Inn
Clubhouse
272,010
9,067
133,890
4,463
Projections unchanged from 2000 Study
Pavilion
268,500
8,950
39,000
1,300
Projections unchanged from 2000 Study.
Day Spa
(Year-round)
30,000
1,000
30,000
1,000
Projections unchanged from 2000 Study
Pool
35,160
1,172
22,500
750
Projections unchanged from 2000 Study
Based on new information, the 2000 projections were
Administration
16,620
554
8,400
280
incorrect All demands doubled for future growth
based on new information
Staff Housing
37,320
1,244
28.980
966
This demand didn't existing in 2000 All demands
doubled for future growth
Subtotal - Inn &
1,659,231
55,308
1,004,460
33 48Y
Total peaks are estimated as the sum of individual
Associated Uses
peaks, which usually do not occur simultaneously
Reduced projected demand of Wastowalor Treatment
Maintenance
20,000
667 0
10.000
333
Plant and I Facility due to plans to reuse
water from the plant effluent
Residences
124
1,112,280
37,076
299
744,000
24,800
200
200 GPD per unit based on orignal study.
Residential
Irrigation
5
202,050
6,735
1,347
Not Applicable
Irrigation demand per unit unchanged from 2000 Study.
Peak Month local is based on highest month of
Total FIOW
2,993,581
99,785
1,75a,460
58r615
combined uses, and does not equal sum of peak
individual uses.
2-4 TIMMONS GROUP .'-':•%
WATER FACILITIES PLAN - UPDATE
CHAPTER 5
WATER FACILITIES PLAN - UPDATE
U5.1 GENERAL
CHAPTER 5
As stated in the original study and subsequent updates, the buildout demands of
Keswick will require additional water system infrastructure. Additionally, the minimal level
of fire protection currently provided throughout the existing system merits discussion of
related infrastructure improvements. This update to Chapter 5 addresses the items which
have changed based on the new usage data including supply, storage and pumping. Where
options are available, the implications, requirements, and critical cost components of each are
presented, with recommendations made at the end of the Chapter. Total costs of each
suitable combination of alternatives are included in Section U5.5.
U5.2 SOURCE OPTIONS
U5.2.1 WELLS -ONLY SUPPLY
With the changes in the supply since the last report update (contamination and
subsequent closing of Well # 3 and addition of Well # 4) the existing supply has increased
(100 GPM vs. 92 GPM). However, the existing supply of three wells with a permitted
capacity of 73,520 gallons per day (gpd) will not be sufficient to meet the ultimate domestic
daily demands plus existing irrigation (peak month) of 99,785 gpd. Therefore, an additional
well will be required to raise permitted capacity to meet projected demands.
The permittable capacity of well supplies in terms of daily demands is governed by
the Virginia Department of Health (VDH) Waterworks Regulations. Essentially, the
regulations require one gallon per minute (gpm) of well yield for every 800 gallons per day
of water to be supplied. For the ultimate projected domestic daily demands plus existing
5-1 TIMMONS GROUP .••';;*%
IN WATER FACILITIES PLAN - UPDATE CHAPTER 5
irrigation (peak month) of 99,785 gpd, a total well yield of 125 gpm is required, 25 gpm
greater than currently available.
In previous discussions with Keswick and Environmental Systems Services (ESS), a
fifth well has been preliminarily planned in the area immediately surrounding the existing
pump house near Route 616. The discussions included drilling a test well near the pump
house to determine a yield and evaluate potential impacts on the existing Estate Wells. This
approach is recommended however, at this time no specific action has been taken regarding
its construction.
Based on current demand projections, if the fifth well is constructed and found to be
of sufficient capacity, the expansion of the well field east and southeast of the Estate's
property would not be required as stated in the 2000 study. However, if the Estate wishes to
secure future additional water sources, acquisition of the adjacent property, currently owned
by Wendell Wood, is recommended since evidence suggests the Everona Limestone
formation underlies the adjacent property. However, further subsurface analysis, including
test drilling and pump testing would be required to confirm this.
U5.3 STORAGE & PUMPING
Although the well pumping rates are currently the limiting factor for the system's
capacity, storage and booster pumping capacities are only slightly higher. With projected
domestic daily demands plus existing irrigation (peak month) consumption at 99,785 gpd,
upgrade to these components will be required as well.
Based on the VDH Waterworks Regulations, storage and pumping requirements are
established by simple calculations. Storage must be equivalent to 50% of design capacity,
and pumping capacity (from non -pressurized storage into the distribution system) is based on
the formula:
Pump Rate = (11.4) (Design Capacity / 400) 0.544
5-2 TIMMONS GROUP
WATER FACILITIES PLAN - UPDATE CHAPTER 5
For the updated 104,252 gpd design capacity, a minimum of approximately 50,000 gallons of
storage must be provided, and pumping capacity must be at least 230 gpm. To meet these
requirements, an additional 14,000 gallons of non -pressurized storage must be provided, and
the existing 200 gpm booster pumps must be upgraded. Costs associated with these upgrades
are listed under Alternative S-1.
In the 2000 study, the projected domestic plus irrigation demands were the
controlling factor in determining storage requirements. With the deletion of future additional
irrigation demands, fire protection (if it is to be provided) would be the controlling factor.
Under these conditions, approximately 60,000 gallons of available fire suppression storage
would be required. This storage could be configured as ground storage (non -pressurized)
with a fire pump or pressurized storage. The previous report updates have included the
following four alternatives for fire suppression:
• Alternative F-1: Fire Pump and Ground Storage at Existing Pump House
• Alternative F-2: Northern Electric Powered Fire Pump and Ground Storage
• Alternative F-3: Northern Pressurized Storage
• Alternative F-4: Northern Elevated Storage
However, Alternatives F-1 and F-4 have been eliminated as possibilities and have not been
included in this update and a new alternative, Alternative F-5: Northern Diesel Powered Fire
Pump and Ground Storage, has been added.
U5.5 SUMMARY & RECOMMENDATIONS
In summary, there are a variety of infrastructure combinations that would meet
Keswick's future demands. A supply alternative must be selected to meet the ultimate
domestic demands. The provision of 1,000 gpm fire flows throughout the Estate and
Subdivision would require additional infrastructure.
5-3 TIMMONS GROUP .••':'%
WATER FAcmrrms PLAN - UPDATE
CHAPTER 5
The combinations presented herein are listed below, with approximate total
construction costs. Supply alternatives do not in themselves provide sufficient (1,000 gpm)
fire protection. Fire protection alternatives include both recommended supply system
coupled with additional infrastructure to meet 1,000 gpm fire demands.
U5.5.1 SUPPLY (DOMESTIC INCLUDING EXISTING IRRIGATION) ALTERNATIVE
Alternative S-1: Well -Supplied
• Source: One new well......................................1 @ $35,000........... $35,000
• Source Water Study..........................................1 @ $30,000........... $30,000
• Ground Storage: 14,000 gallons (Non -pressurized) ..... $55,000........... $55,000
• Pumping: Upgrade 200 to 230 gpm.................2 @ $15,000........... $30,000
TOTAL CONSTRUCTION COST..........................................................$150,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (-15%) .....$25.000
TOTAL PROJECT COSTS.................................................................$175,000
U5.5.2 FIRE PROTECTION ALTERNATIVES
Alternative F-2: Northern Electric Powered Fire Pump and Ground Storage
• Pumping: 1,000 gpm fire service ............................. $70,000........... $70,000
• Ground Storage: 60,000 gallons (Non-pressurized)...$165,000.........
$165,000
• Pressure Storage: Northern 6,000 gallons
................ $30,000...........
$30,000
• Northern Domestic Pumping: Dual Units
........ 2 @ $209000...........
$409000
• Sitework....................................................................$30,000...........$30,000
• Electrical...................................................................$609000...........$609000
• 20'x20' Building (Precast Concrete) ........................
$40,000...........
$40,000
• 300 kW Genset / 400A ATS...................................
$155,000.........
$155,000
• Telemetry System (Radio) ........................................
$259000...........
$25,000
• Alternative S-1: Well Supply ..................................
$175,000.........
$175,000
• Less Ground Storage: 14,000 gallons
................ $55,000.........
-$559000
• Less Pumping: Upgrade 200 to 230 gpm
... 2 @ $15,000.........
-$30,000
TOTAL CONSTRUCTION COST..........................................................$705,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (-15%)
...$105.000
TOTAL PROJECT COSTS.................................................................$810,000
5-4 TIMMONS GROUP .--*;;*.
V WATER FACILITIES PLAN - UPDATE
Alternative F-3: Northern Pressurized Storage
CHAPTER 5
• Pressure Storage: 60,000 gallons ........................... $600,000......... $6009000
• Pumping: 1000 GPM Booster Pump (35 HP) ........... $259000........... $259000
• Sitework....................................................................$309000...........$30,000
• Electrical...................................................................$359000...........$359000
• 12'xl4' Building (Precast Concrete) ........................ $259000........... $259000
• 100 kW Genset / 200A ATS................................... $1109000......... $1109000
• Alternative S-1: Well Supply .................................. $1759000......... $1759000
• Less Ground Storage: 14,000 gallons ................ $559000......... -$559000
• L-ess Pumping: Upgrade 200 to 230 gpm...2 @ $15,000.........-$30,000
TOTAL CONSTRUCTION COST..........................................................$9159000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (-15%) ...$135.000
TOTAL PROJECT COSTS..............................................................$1,050,000
Alternative F-5: Northern Diesel Powered Fire Pump and Ground Storage
• Pumping: 1,000 gpm diesel fire service ................. $135,000.........
$135,000
• Ground Storage: 60,000 gallons (Non -pressurized) ... $165,000.........
$165,000
• Pressure Storage: Northern 6,000 gallons
................ $309000...........
$309000
• Northern Domestic Pumping: Dual Units
........ 2 @ $209000...........
$409000
• Sitework....................................................................$309000...........$309000
• Electrical...................................................................$409000...........$409000
• 20'x2O' Building (Precast Concrete) ........................
$40,000...........
$409000
• Telemetry System (Radio) ........................................
$259000...........
$259000
• Alternative S-1: Well Supply ..................................
$175,000.........
$1759000
• Less Ground Storage: 14,000 gallons
................ $55,000.........
-$559000
• Less Pumping: Upgrade 200 to 230 gpm...2
@ $15,000.........
-$30,000
TOTAL CONSTRUCTION COST..........................................................$595,000
ADD ENGINEERING, ADMINISTRATIVE & CONTINGENCIES (-15%) .....$90.000
TOTAL PROJECT COSTS.................................................................$685,000
In comparison of all three fire supply alternatives, Alternative F-5 is by far the least
expensive although, like the other alternatives, it will require proper maintenance to remain
in proper working order and therefore operational costs must also be considered. As
discussed in previous versions of this report, the non -pressurized storage (included in
Alternative F-2 and now Alternative F-5) would be fed from the already -pressurized
5-5 TIMMONS GROUP .-**:*.
V WATER FACILITIES PLAN - UPDATE CHAPTER 5
distribution system and returning this water back into the system would require re -pumping,
thereby increasing energy costs. In addition, both Alternatives F-2 and F-5 would contain
five pumps (two southern and two northern domestic supply pumps, and one fire pump),
versus only three for Alternative F-3, resulting in added regular maintenance and repair costs
for those alternatives. However when comparing the high capitol cost of Alternative F-3 to
the relatively small increase in operation and maintenance costs associated with the others,
Alternatives F-2 and F-5 become more favorable. Furthermore, since Alternative F-5 has the
lowest capitol cost and will provide more reliable operation, since it requires less mechanical
equipment than Alternative F-2, it may be the best option for Keswick to select.
U5.5.3 RETROFITTING EXISTING SYSTEM
To maximize the effectiveness of the new fire suppression system, fire hydrants will
need to be retrofitted to the existing water system in the existing developed areas of Keswick.
According to the Albemarle County Service Authority Regulations, generally, fire hydrants
shall be placed no closer than 40 feet nor further away than 400 feet from all major structures
and no fire hydrant shall be more than 800 feet from any other hydrant measured along the
centerline of the road. Per these requirements, the schematic shown on the following page
has been prepared to show the approximate location of the existing fire hydrants (in green),
where the new fire hydrants are proposed in Section IX (in blue) and where new fire hydrants
should be retrofitted to the existing system (in red). The locations shown are approximate
and should be field verified.
In addition to new fire hydrants, a connection will need to be made between the
existing water system and the existing fire suppression system at the Inn (Hall and
Clubhouse). Currently the fire suppression system at the Inn is designed to pull water from
the swimming pool to supply the system during a fire event. Once a new fire protection
alternative is constructed, the system at the Inn will need to be modified to take advantage of
the new system. This will include a connection between the water system and the Inn and the
abandonment of the existing connection to the pool.
5-6 TIMMONS GROUP .--*W*.
WATER FACILITIES PLAN - UPDATE
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CHAPTER 5
5-7 TIMMONS GROUP .--*:.%
IT, WATER FACILITIES PLAN - UPDATE CHAPTER 5
U5.5.4 CONCLUSION
The types and magnitude of future water demands at Keswick will require additional
supply, storage and/or pumping capacity, and linework additions and upgrades. As future
development occurs, new waterlines should be constructed to permit adequate (1,000 gpm)
fire flow to all areas, which will generally require 8-inch diameter lines. To provide
adequate (1,000 gpm) fire flow throughout the system, additional storage requirements of
60,000 gallons should be provided on the north end of the system and fire hydrants shall be
retrofitted to the existing system. The fire protection alternative selected will need to
consider capitol costs, operation and maintenance costs and reliability.
5-8 TIMMONS GROUP .••':••.
TIMMONS GROUP .••""%
1001 Boulders Parkway
Suite 300
Richmond, VA 23225
(804) 200-6500 • FAX 560-1431
TIMMONS GROUP .--"*"•
1001 Boulders Parkway
Suite 300
Richmond, VA 23225
(804) 200-6500 • FAX 560-1431