HomeMy WebLinkAboutSP201500032 Study 2015-12-22Re- Store'N Station — Phase II — Water Usage Analysis dated 12/8/2015
1. Water usage for existing development (Phase 1):
a. Attached is the Commissioning Report —Water and Wastwater Systems for TM55B —1 done
by Old Dominion Engineering dated Feb 2, 2015. It states that for period Sept 12, 2014 to
October 23, 2014, the average water usage was confirmed to be 204.4 gallons per day. For
period October 23, 2014 to January 28, 2015, the average water usage was confirmed to be
243.4 gallons per day. The usage during the commissioning of the septic system reflects the
first few months of the store opening. This period had less than the ultimate anticipated
customer activity but does provide confirmation of the flows that were treated at that time.
This report also provides the instructions for reading the water meter. After 6 months, the
store achieved the anticipated customer activity.
b. Attached is the water meter log sheets for the period 9/9/2014 through 1211115 which is a full
year ( 52 weeks) plus 9 weeks into the second year of data. The actual readings are
provided with the date of the reading. Written in the right side margin is the actual gallons per
week/ gallons per day. The first 26 weeks of operation (9/9/14-3/10/15) average was 250
gpd. The second half of the year of operation (3/17/15-9/17/15) average was 408 gpd. The
first 9 weeks of the 2nd year of operation average was 232 gpd.
c. Analysis of actual Phase I data: In the months of June and July 2015, there was a seven
week period (6/9 — 7/21) of higher meter readings. It was determined that the uninformed
employees had been washing the sidewalk with the water house instead of broom cleaning as
should have been done. Once this was corrected, the meter readings reflected water usage
in the more normal range of 346 to 400 gpd. For purposes of this analysis, the higher
average of 408 gpd is being used without factoring in the most recent couple month with the
average of 232 gpd. All of this information does prove that the existing development can
operate at a fraction of the water allowed for this site. The actual water usage is in the range
of 25 to 14% of 1,625 gpd.
FUTURE ANALYSIS: For purposes of this analysis, the higher average of 408 gpd is being
used which is 25% of the allowable water usage of 1,625 gpd. This leave 75% or 1,217 gpd
available to serve the Phase it expanded development.
A. The existing water usage for the 2,775sf convenience /retail store is proven with meter
reading data (see above). The Phase II expansion water usage projections are presented
below. It should be noted that calculations below may not completely reflect the high
efficiency toilets (HET's) with 1.28 gallons per flush and the urinals flushes of 0.1 gallons per
flush that are have been and will be installed. The two stage flush toilets now available even
offer a greater measure of water conservation and will likely be installed in the 6 restrooms
required by code (1 each tenant unit —1 st floor, 1 retail auto, 1 auto shop, 2/3 to serve the 2nd
floor office space — total 6). In addition as typical in any commercial restroom (As in the
County Office Bldg), the use of electronic auto timers valves on the hand wash sinks which
provides a 3 — 6 second flow for hand washing saves even more water. Therefore, these
calculations are higher than the anticipated water use so conservative. For instance the
additional space being added to the existing convenience store that will increase the square
footage from 2,775 sf to 5,497 sf will be served by the existing restroom facilities. Therefore,
minimal additional water usage is anticipated. Regardless the new space is counted below in
both calculations.
B. The analysis below is based upon two different design manuals:
1. USEPA Onsite Wastewater Treatment Systems Manual -
Table 3 — 4 (attached) This table incorporates the effect of the 1994 EPA Act that
limited toilets to 1.6 gpf — see note below the table.
The most applicable category now tnat the site will nave convernenceiretan, office, tenant
rental spaces, and auto shop repair- the Shopping Center category reflects a mixture of uses. The
category uses the number of employees (occupants) which is a reasonable basis for this type analysis.
The table indicates a volume of 10 gpd per employee and 2 gpd per parking space to calculate the
r)roiected wastewater caoacity flow rates for commercial sources = water consumotion.
USE
12,818 X 51.2 - 76.8/1,OOOSF
EMPLOYEES
CONVENIENCE/RETAIL
EXISTING OPERATIONS
Included in meter data
16,022 SF X.8 to get ultimate
ADD FOR DRIVE THRU
2
RETAIL TENANT SPACES
2 PER RENTAL STORE X 2
4
AUTO RETAIL
2 COUNTER PEOPLE
2
AUTO REPAIR SHOP
4 MECHANICS
4
OFFICE USE — 9,175SF x.8
1 EMPLOYEE /200 NET SF
37
Total employees
49
CALCULATE WATER USAGE. 49 Employees x 10 gpd /employee = 490 gpd
106 spaces x 2 gpd /space = 212 gpd
The projected water usage based upon employees in Phase II is 702 gpd.
Peak usage for Phase I is 534 gpd added to this projection = 1,236 gpd. This is only 76% of the 1,625
gpd allowed. Using the average of 408 gpd the projected is 1,110 gpd or 68% of the allowable 1,625
gpd.
2. Second approach using Virginia Department of heaitn 12 VAC 5- 690.Waterworks
Regulations — Capacity of Waterworks states the design capacity "shall exceed the
maximum daily water demand of the system ". This table incorporates a safety factor to
meet this requirement. Page with table is attached. This regulation was adopted well
before 1994 (around 1980) and has not been updated from when toilets used 3.5, 5, 7
gallons per flush (gpf).
Shopping Centers, per 1,000 sf of ultimate floor area usage is 200 — 300 gpd.
Service Stations, per vehicle served — 10 gallons
To calculate the Shopping Center ultimate floor area = net usable area 0.80 factor is used.
To adjust the water usage to take into account that these water consumption rates were adopted in
1980. The 1994 EPA Act federal regulation limited the amount of water per flush for toilets to a maximum
of 1.6 gpf or 1.28 gpf for HET's (high efficiency toilets). When comparing the medium older flush toilet
water volume of 5.0 gpf to the HET of 1.28 gpf — the HET uses 25.6% of the water consumption. (No
adjustment is being made for the modern urinals which use 0.1 gpf when water consumption was 1.0
gpf which saves 90% on water usage)
Therefore, the 10 gpd per vehicle adjusted for installing HET's will be 2.56 gpd.
The shopping center consumption of 200 — 300 ood is adiusted to be 51.2 — 76.8 gad.
Shopping center including office
12,818 X 51.2 - 76.8/1,OOOSF
656 gpd — 984 gpd
and retail is a total of
16,022 SF X.8 to get ultimate
floor area = 12,818 sf
excludes auto shop & tire
Auto repair shop
4 bays x .5 car /hr x 8 hrs /day
41 gpd
= 16 cars per day x 2.56 gpv
TOTAL GPD
RANGE OF 697 —1025 GPD
The peak usage of Phase I is 534 gpd added to this range = 1231 —1559 gpd
This is 93 to 96% of the 1,625 gpd allowed. Using the average of 408 gpd the projected is 1,105 -1433
gpd or 68% 88% of the allowable 1,625 gpd.
In conclusion, both the USEPA and the Virginia Department of Health, Waterworks Regulations provide
a reasonable basis for analysis and both include a safety factor for the design of wastewater systems.
The results based upon these calculations for the Phase II expansion are fairly close. Using the
USEPA manual — the average is 68% of the allowable 1,625 gpd. Using the VDH manual, the average is
68 — 88% of the allowable 1,6245 gpd. Both converge at the 68% level with the VDH manual (which is
the most out of date) giving a range. Therefore, the projected water usage is approx. 1,110 gpd or 68%
of the 1,625 gpd allowed.
It should be acknowledged that water conservation is both an important environmental concern and cost
saving measure and all new plumbing fixtures are subject to the USEPA regulations to reduce water
consumption. The property owner in this case is very aware of the mandate to operate under the limit
of 1,625 gpd which is all the system can physically withdraw from the well with the flow device limitation
in place. The water withdrawal cannot be exceeded. These projections are to confirm that it is
reasonable to allow for this property to be developed as proposed and not exceed the by -right limit for
HC use in the rural areas of 400 gallons per day per acre limit.
Attachments.
Water meter reading log - 8 sheets
USEPA design Manual sheet — 1 page
VDH design Manual sheet — 1 page
Old Dominion Engineering
February 2, 201
Jeff Sprouse
Jeffries II, LLC
P.O. Box 910
Crozet, VA 22932
SUBJECT: TM 5513 -1 - COMMISSIONING REPORT - WATER AND
WASTEWATER SYSTEMS
Property: TM 5513-1, 6099 ROCKFISH GAP TPKE Crozet, VA 22932 4.06 Acres
The convenience store started operations at the end of third quarter 2014. The
wastewater treatment system was commissioned and started up from September 12, 2014
until October 23, 2014. Multiple visits were made to test and adjust the system during
that time period. Process treatment systems had to be optimized to compensate for the
lower influent wastewater flow rates from the store to keep effluent limits within permit
guidelines and ensure plant survival in the recirculating vegetative gravel filter. Despite
the lower flow rates encountered all systems operated within effluent tolerances.
The VDH permitted effluent strength limits are:
• BOD5 < 30 mg /I
• TSS < 30 mg /l
• TN < 25.5 mg/l
Fourth quarter sample results were all within compliance:
• BODs <2 mg/1
• TSS = 2 mg/1
• TN = 3.68 mg/1
The fourth quarter inspection report and sample results have been submitted to VDH. A
copy of the Field Abbreviated Inspection Certification is provided.
The VDH mandatory monitoring requirements of the system are:
• Quarterly Inspections
o The next inspection is due first quarter 2015
• Once per Year Sample for BODs, TSS, and TN
o The next round of compliance samples are due fourth quarter 2015
Water Usage
The water usage was monitored during the commissioning period (September 12, 2014 to
October 23, 2014). The average water usage during that time was 204.4 gallons per day.
It would be anticipated that peak water usage would exceed the average water usage.
However, both the wastewater system and water system have flow equalization
components which serve to dampen the withdrawal of water from the aquifer and the
ultimate release of treated effluent back into the soil.
To obtain a longer term view of the water usage we read the water meter again on
January 28, 2015. The average water usage from the end of the commissioning period
(October 23, 2014) to January 28, 2015 was 243.4 gpd. It is recommended to have the
staff read the water meter once per week to develop long term weekly averages of water
usage. A water meter reading guide and log sheet template is attached for your use.
The letter serves to confirm that the water usage (and withdrawal) is less than the
maximum permitted amount of 1,624 gpd.
. 1,'�,, OF vrR� I
V,
Sincere y,
Michael Craun PE
Old Dominion Engineering
2036 Forest Drive • Waynesboro, VA 22980
PHONE (540) 942 -5600 • FAX (540) 213 -0297
Thousands
Ten
Thousands
Hundr&
Thousan
Millions
Meter Reading Guide
Meter Reading
0,035,112.4
Ones
Tenths
Tens
Hundreds
d
Water Meter Lo
TM 55 B -z g
6099 ROckflsh Gap Turnpike Crozet, VA 22,932
Date Time Water Meter Reading
(gallons) Name
12.3
OD
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ol
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Water Meter Log
TM 55 B-1
6099 Rockfish Gap Turnpike Crozet, VA 22932
213
Date Time Water Meter Reading +
(gallons) Name 1_
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a hr o o • ..
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Water Motor Log
TM 56 B-1
6099 Rodfth Gap Tumpike Crozet, VA 22932
Date
Time
Water Meter Reading
Name
(gallons)
A
t
0
Zc- r
7112
-10
I
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016
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13
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t (i 10 72-36
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"Pr 10 CUUV 1 : aCVM UL1J Uun1111U11 t11U111CCK111b ultu- CA0 -UCw7 / rr. 1
T" 394 yPW et Bldg eleter flow tlatss item ootrutteldel soliroa�
'8o1eesyatee>taeninparole thenZDpeople milt to ngdeted w%W U8EPA3CWu V Undergrmind huecwn Cants! (UkC) Pmgmm. See
tNV1 wwA* Lq%ftb*M*lefird br monitbrleafon.
' Theea dde trlrl&p "1tt Ot W nt 10ft<11er m ptyig *11b l u U.S. E=W Pok;y Ad (EPACT) d 1994.
�r� D�gcnel d erafamagve werltevia subwrrTace wallbwabr iMlM40on syyferde r8 ttar+ned by Class V UIC re91>ierinrls b protect grolend wafer. See
tr Mplhwwape�iDfihn4lormmkdoftisliom
SDUw Crites Errs TchdM oglacm,1996,
3.3.3 Varla #iy of wastewater flow
Variability of wastewater flow is usually dwracter-
ixcd by daily and !warty minimum and maximum
flows and instantaneous pestle flows tbat occur
during the day. The intcmuttent oect nwme of
individual wastewater- generating activities can
eresu large variations in wastewater flows from
residential or nommidential establishments- This
variability can affect. gravity -fed onsile systems by
potentially causing hydraulic.overioads of the
system during peals Sow condetions_ Figure 3 -3
illustrates the routine fluctuations in wastewater
flows for a typical residential dwelling,
Wastewater flow can vary significantly from day to
day. Minimtmo hourly flows of zero are typical feu
FIgttne 3.3. Dally indowwater use paltlern for 91,091e4smity residence
tat 4
� 3
� l
1
e` 2
s
OL a
T _ TOILET D - DISH 1MMN
L - LAUNDRY w- WATER 90M UM
9 - 8ATH 78HOWER 0 - OTHER
T -4v-4p, T
9 N 3 8 9 1MI
TIME Of DAY
Source: Univer%4 of V Mccnsin,1970
USM Ow* iffisomfor Tisatmem Syabrns Msrnral 8-7
(J's, E.--PA
Flan, P&MAhrnitNlalr
Fbwr titaraliraWft
Foollilly
Urdt
._RM40
--
Ai"d
Passerlw
2-4
3
9 -16
11
Apu mmet h wo
?rraDn
4(1-SD
50
15o -300
190
Aulomobile service station`
Vehlclese ved
8-15
12
30-57
45
ElrQigyae
9-15
13
34-57
49
Sat
Customs,
1-6
3
4-19
11
Effooyee
t0-16
13
35-61
49
Baebil+g house
Person
25-80
40
95-230
150
Dspartnwtstane
Tolat room
400 -60D
5C
t,S00 -2,300
1,900
Emp"M
8-15
10
80-57
36
Etas!
ot"M
4040
50
150-9%
190
Empkyree
6-13
14
34-49
38
Industdal00ding (senhary waste only3
Employee
7 -18
13
25-61
49
uundry0all -MMON)
MWANre
45044
590
1,70¢ -2-W
2,100
wash
45-55
50
179-210
190
CaAce
Employee
7 -f8
13
26:-81
49
Public fee"
use
3--6
5
11-23
19
Res"UMM (fth "at)
Meal
2-4
3
6--15
11
Conven"Mal
CuslDrner
8-10
9
3036
34
Shot! older
Ctkolrtar
3-8
6
11 -30
23
Bartel Wsip
Customer
2--4
3
8-15
11
MOPPINIMW
Employee
7 -13
110
26-49
38
Parking space
1 -3
2
4--11
8
- T?Mpgr—
Seal
2-4
3
8-15
11
'8o1eesyatee>taeninparole thenZDpeople milt to ngdeted w%W U8EPA3CWu V Undergrmind huecwn Cants! (UkC) Pmgmm. See
tNV1 wwA* Lq%ftb*M*lefird br monitbrleafon.
' Theea dde trlrl&p "1tt Ot W nt 10ft<11er m ptyig *11b l u U.S. E=W Pok;y Ad (EPACT) d 1994.
�r� D�gcnel d erafamagve werltevia subwrrTace wallbwabr iMlM40on syyferde r8 ttar+ned by Class V UIC re91>ierinrls b protect grolend wafer. See
tr Mplhwwape�iDfihn4lormmkdoftisliom
SDUw Crites Errs TchdM oglacm,1996,
3.3.3 Varla #iy of wastewater flow
Variability of wastewater flow is usually dwracter-
ixcd by daily and !warty minimum and maximum
flows and instantaneous pestle flows tbat occur
during the day. The intcmuttent oect nwme of
individual wastewater- generating activities can
eresu large variations in wastewater flows from
residential or nommidential establishments- This
variability can affect. gravity -fed onsile systems by
potentially causing hydraulic.overioads of the
system during peals Sow condetions_ Figure 3 -3
illustrates the routine fluctuations in wastewater
flows for a typical residential dwelling,
Wastewater flow can vary significantly from day to
day. Minimtmo hourly flows of zero are typical feu
FIgttne 3.3. Dally indowwater use paltlern for 91,091e4smity residence
tat 4
� 3
� l
1
e` 2
s
OL a
T _ TOILET D - DISH 1MMN
L - LAUNDRY w- WATER 90M UM
9 - 8ATH 78HOWER 0 - OTHER
T -4v-4p, T
9 N 3 8 9 1MI
TIME Of DAY
Source: Univer%4 of V Mccnsin,1970
USM Ow* iffisomfor Tisatmem Syabrns Msrnral 8-7
(J's, E.--PA
Virginia Department of Health Revised December 14, 2006
12 VAC 5 -590, Waterworks Regulations Pro, I q 0l
The following shall be considered when selecting processes to achieve treatment
goals:
A. The quality and variability of the source water.
B. Possible future changes in the quality of the source.
C. Water quality goals, including the growing desire of the public for better water.
D. When removal of contaminants for which BAT hels been specified is necessary,
processes classified as BAT.shall be employed.
, E. When treatment technique requirements have been established in lieu of MCLs,
processes specified by such requirements shall be employed.
G F. POE or POU devices shall not be utilized for long -term compliance with PMCLs.
Such devices may be considered for short term, interim use, as a condition of a
variance or exemption issued by the commissioner.
12 VAC 5- 590 -690. Capacity of waterworks.
esi n aci of the waterwork shall exceed the maximum daily water
demand of the system. aterw –b—Ms s a normally be designed on the following basis of
water consumption. If deviations are made, they shall be based on sound engineering
knowledge substantiated in the designer's report and approved by the division.
A. Dailv water consumption rates (annual daily water demand):
E47
Dwellings, per person
100 gpd
High schools with showers, per person
16 gpd
Elementary schools without showers, per
person
14 gpd
Boarding schools, per person
75 ggd
Motels at 65 gallons per person, minimum
per room
130 gpd
Trailer courts at three persons per trailer,
per trailer
300 gpd
Restaurants, per seat
50 gpd
Interstate or through highway restaurants,
per seat
180 gpd
Interstate rest areas per person
5 g2d
Service stations, per vehicle served
10 gpd
nes,r —per person, er eight-hour shift
15 -35 gpd
Shopping centers, per 1,000 s .ft. of ultimate floors ace
200 -304 gpd
Hospitals, per bed
300 gpd
Nursing homes, per bed
240 gpd
Home for the aged, per bed
100
Md
Doctor's office in medical center
500
Qd]
Part III Article 1 - 2
Well Certification Report
Restore N Station
6115 Rockfish Crap Tumpike
Crozet, VA
4.06 acres
TM 55B-1
Albemarle County
Old Dominion Engineering
June 26, 2012
Well Construction Certification
6/26/2012
The well was installed by Matheny Well Drilling and Pump Service on May 3 and May 4
2012. The well construction was supervised by Michael Craun PE. The well was logged
by Steve Gooch CPG. The well driller's completion report and the CPG well log are
attached to this certification. The well was installed in the location designated on the
permit. This engineer's certification serves as verification of the well installation and log.
Notes:
1. The well yields were measured using the stopwatch and bucket technique. The
water bearing zone at 400'-405' was in excess of 50 gpm. The intended use of the
property will require I gpm average.
2. The installation of the casing and cement grouting were observed by Joshua
Kirtley VDH. The VDH Inspection is on file at Albemarle County VDH. An
email confirmation is attached to this certification.
3. The well was permitted as a H B well but was constructed to IIB standards. Prior
to converting the well to a non community IIB well, the following items will need
to be completed:
a. Submit application to Office of Drinking Water VD14 (ODW VDH) in
Lexington, VA.
b. Laboratory testing of water quality samples as required by ODW VDH.
c. 48 hour well drawdown test.
I hereby certify that on 513/W12 qnd 5/4/2012, I, or an employee under my direct supervision, inspected this well construction. The
well has been in;(12
led mp in accordance with the construoiion permit 101-08-0497 and is in compliance with the Private
Well RegulutiunaY 30 seq) and the plans and specifications for the proj wt.
PE signature: Date: +� Z
Print Name: C N � s
Page 1 of I Old Dominion Engineering • 2036 Forest Drive Waynesboro, VA 22980.540-942-5600 - olddomeng@ntelos.net
John Y. Gooch, P.E. �OC�Z Steve Gooch, C.P.G.1A.O.S.E.
Jyg@gooch-eng.comspg@gooch-eng.com
434
Matthew P. Gooch, P.E. Phone ) 293-7449
mpg@gooch-eng.com �s� .r g� _r" 4C_ Fax (434) 293-5137
1821 Broadway Street Charlottesville, Virginia 22902 www.gooch-eng.com
Water Well
ReStore'N Station
Crozet, Virginia
Well Data
Depth — 425 ft.
Depth to bedrock —15 ft.
Static Water Level — 40 ft.
Yield — 50 gpm+*
Casing — 0-5411.
Grout— 2-54 ft.
Water Bearing Zones
1) 100-105 ft. -- 5 gpm
2) 400-405 ft. — 50 gpm+**
** estimated by well driller
Well ug
Depth Material Description
(ft.)
4-15 Soil and weathered rock
15-425 Granodiorite (Blue Ridge Complex)
COMMONWEAUM OF VIRGINIA
UNIFORM WATER WELL COMPLETION REPORT
Owner I. r"I r i'' Tn
Address 4A.'
Phone
WELL DATA
GENERAL INFOR ATION
Dri l ling Method
Depth to bedrock T /
Static IWatcr Level
Well Disinfected (Y orri)
Total Depth of Weil
Length of test
Natural tlo ,
Amount used
RECEIVED JUN 2 0 2012
1-11Mnp ID
VDI[ Permit
V%VCB PActmit
County rL2('�►'t_
GROAT
Prom �_ _ To
Fiore Hole Size
Type
Method ► iA eA li 3
CASING
From n To
Material _�
Weight/Schedu le 21
Datc Completed
Yieid_4j'0 } (GPM)
Stab;lized Nater Lev -0
Disinrccthint used
Private Well: Domestic ✓ AgririuRural Industrial Monitoring
Public well: Community Non Community _
DRILLERS LOG, �111�
Depth De—wriptiunorFormaiion or sediment Remarks r1
woe
Grp.
f6o _ GPM
�Y
q00'.1 40S 5b+ GPM
1 certify that the infbrination contained here is true and that this well was installed :nod constrctcd in accordance with
the permit and further that the well complies with all applicable state and local regulations, ordinances and laws.
Name Motherly 1Vell Drilling & Pump Service, hic.
Address 2797 Kacey Lone
Afton, VA 22920
Phono# 50•4564949
Drillers ,. noun; license #2719004083
171rte:J Eieitrescating Virginia Contractors License Numhe,• {117282
KE: weir t°ompienon atatement Ke ,tore iv btanon http://webmail.ntelos.neVsrclprinter friendly_bottom.php?passed_Cnt.,.
From: "Kirtley, Joshua (VDH)" <Joshua.Klrtley@vdh.virginia.gov>
Subject: RE: Well Completion Statement Re Store N Station
Date: Mon, June 25, 2012 11:48 am
7o: "oiddomeng@ntelos.net" <olddomeng@nteios.net>
Mike:
Good morning. Hope you're doing well.
Attached is the information that you requested for Re Store N Station. Please review and let me know if you have any questions.
would also like to mention that i performed an inspection an the grouting procedure on 04 May 2012. At that time, I confirmed
that the well contained 54' of casing and that the well was pump grouted to the surface with Portland cement.
Josh
Josh Kirtleyl Environmental Health Specialist, Senior
Thomas Jefferson Health District I Albemarle County, Virginia
1138 Rose Hill Drive I Charlottesville, VA 22903
434-972-6289
Old Dominion Engineering
August 25, 2014
Jeff Sprouse
Jeffries II, LLC
P.O. Box 910
Crozet, VA 22932
SUBJECT: TM 5511-1- VERIFICATION OF WATER WITHDRAWAL RATE
FROM WELL
Property: TM 55B-1, 6099 ROCKFISH GAP TPKE Crozet, VA 22932 4.06 Acres
The maximum allowable water withdrawal rate from the well at the Restore N Station
convenience store is 1,624 gallons per day based upon the 400 gallons per acre
Albemarle County restriction. A 1 gallon per minute dole control valve and a tamper
proof meter were installed in order restrict the water withdrawal from the well and to
monitor the actual rate of water withdrawal. On 8/25/2014 Old Dominion Engineering
(ODE) performed an inspection of the installation to ensure compliance with the
specifications/county requirements and to test the actual water withdrawal rate.
Installation Certification
The 1 gpm dole flow control valve was installed correctly. The Dole flow control valve
is a non adjustable flow regulator which limits the flow of water from the well to 1 gallon
per minute (1,440 gallons per day). These valves are typically used to prevent a low
water yielding well from excessive water withdrawal. Dole flow control valves are
guaranteed to operate within 15% of the stated flow rate. The flow rate varies due to
manufacturing tolerances and water temperature.
A 518" Sensus SRII Tamper Proof Water Meter was installed.
The water storage tank was installed so as to require an 8" float differential between the
on/off floats (548 gallons minimum per fill cycle).
Certification Test
The actual performance of the dole control valve was tested to ascertain the actual water
withdrawal rate from the well. The test conducted was a cumulative flow test with water
meter and time readings taken at increasing duration throughout the test. The test was
conducted for one hour and 42 minutes. The water meter dial is calibrated to .1 gallon
increments. Readings during the test were interpolated to the closest .05 gallon
increment. Each test reading was extrapolated to a daily flow by multiplying the gallons
per minute by 1440 minutes per day. The overall rate was calculated to determine the
"extended flow rate" rating of the dole control valve.
Cumulative Flow Test Results
Meter Reading
(gallon)
Elapsed Time
(minutes)
Ogallons
A Time
(minutes)
Flow
(gallonsiminute)
Extrapolated Flow
(gallons/day)
2
0
6.4
4
4.4
4
1.10
1584
7.5
5
1.1
1
1.10
1584
9.6
7
2.1
2
1.05
1512
13.9
11
4.3
4
1.08
1548
17.1
14
3.2
3
1.07
1536
21.2
18
4.1
4
1.03
1476
27.55
24
6.35
6
1.06
1524
35.9
32
8.35
8
1.04
1503
46.2
42
10.3
10
1.03
1483
56.4
52
10.2
10
1.02
1469
66.65
62
10.25
10
1.03
1476
76.9
72
10.25
10
1.03
1476
107.45
102
30.55
30
1.02
1466
Overall
105.45
102
1.03
1489
All test readings during the cumulative flow test were less than 1,624 gpd extrapolated.
The peak flow rate decreased from 1.1 gpm to 1.03 gpm after about 42 minutes. The
extended flow rate of the dole control valve assembly installed was 1.03 gpm which
correlates to a maximum available daily withdrawal rate of 1,489 gallons per day from
the well. The assembly meets the requirement to limit the water withdrawal to less than
1,624 gallons per day.
Sincere y,
Michael Craun PE
Old Dominion Engineering
2036 Forest Drive • Waynesboro, VA 22980
PHONE (540) 942-5600 • FAX (540) 213-0297