HomeMy WebLinkAboutWPO200700062 Calculations 2007-07-27 APPROVED
by the Albemarle County
Community Development Department
Date ._.._._ . C G3C 2 c,)0
file: We()' .- 00 .
EROSION AND SEDIMENT CONTROL NARRATIVE
FOR
LAUREL PARK LANE
July 27, 2007
LOCATION:
Block C7, C8, C9
Hollymead Town Center
Rio District, Albemarle County, Virginia
OWNER:
Virginia Land Company
195 Riverbend Drive
Charlottesville Virginia 22911
(434) 979 -8181
PREPARED BY:
Dominion Development Resources, LLC
172 South Pantops Drive
Charlottesville VA, 22911
(434) 979 -8121
F: (434) 979 -1681
A. MINIMUM STANDARDS (MS):
All applicable Virginia Erosion and Sediment Control Regulations and Minimum
Standards shall be adhered to during all phases of construction. These include, but
are not limited to the following:
1. STABLIZATION OF DENUDED AREAS:
Permanent or temporary soil stabilization shall be applied to bare areas within four
days after final grade is reached on any portion of the site. Temporary soil
stabilization shall be applied within four days to denuded areas that may not be at
final grade, but will remain dormant or undisturbed for longer than 30 days.
Permanent stabilization shall be applied at areas that are to be left dormant for
more than 1 year.
2. STABILIZATION OF SOIL STOCKPILES:
During construction of the project, soil stockpiles shall be stabilized or protected
with sediment trapping measures. The applicant is responsible for temporary
protection and permanent stabilization of all soil stockpiles on site as well as soil
intentionally transported from the project site.
3. PERMANENT VEGETATIVE COVER
A permanent vegetative cover shall be established on denuded areas not
otherwise permanently stabilized. Permanent vegetation shall not be considered
established until a ground cover is achieved that, in the opinion of the County
Inspector, is uniform and mature enough to survive to inhibit erosion.
4. TIMING & STABILIZATION OF SILT TRAPPING MEASURES:
Sediment basins and traps, perimeter dikes, sediment barriers and other
measures intended to trap sediment shall be constructed as a first step in any land
disturbing activity and shall be made functional before upslope land disturbance
takes place.
5. STABILIZATION OF EARTHEN STRUCTURES:
Stabilization measures shall be applied to earthen structures such as dams, dikes
and diversions immediately after installation.
6. SEDIMENT TRAPS AND BASINS:
A sediment basin shall control surface runoff from disturbed areas that is
comprised of flow from drainage areas greater than or equal to three acres. The
sediment basin shall be designed and constructed to accommodate the anticipated
sediment loading for the land disturbing activity. The outfall device or system
device shall take into account the total drainage area flowing through the disturbed
area to be served by the basin.
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7. CUT AND FILL SLOPES:
Cut and fill slopes shall be designed and constructed in a manner that will
minimize erosion. Slopes that are found to be eroding excessively within one year
of permanent stabilization shall be provided with additional slope stabilizing
measures until the problem is corrected.
8. CONCENTRATED RUN -OFF DOWN CUT OR FILL SLOPES:
Concentrated runoff shall not flow down cut or fill slopes unless contained within
an adequate temporary or permanent channel, flume, or slope drain structure.
9. WATER SEEPS FROM A SLOPE FACE:
Whenever water seeps from a slope face, adequate drainage or other protection
shall be provided.
10. STORM SEWER INLET PROTECTION:
All storm sewer inlets that are made operable during construction shall be
protected so that sediment -laden water cannot enter the conveyance system
without first being filtered or otherwise treated to remove sediment.
11. STABILIZATION OF OUTLETS:
Before newly constructed stormwater conveyance channels are made operational,
adequate outlet protection and any required temporary or permanent channel lining
shall be installed in both the conveyance channel and receiving channel.
12. WORK IN LIVE WATERCOURSES:
When work in a live watercourse is performed, precautions shall be taken to
minimize encroachment, control sediment transport and stabilize the work area to
the greatest extent possible during construction. Nonerodible material shall be
used for the construction of causeways and cofferdams. Earthen fill may be used
for these structures if armored by nonerodible cover materials.
13. CROSSING A LIVE WATERCOURSE:
When a live watercourse must be crossed by construction vehicles more than
twice in any six month period, a temporary stream crossing constructed of
nonerodible materials shall be provided.
14. APPLICABLE REGULATIONS:
All applicable federal, state and local regulations pertaining to working in or
crossing live watercourses shall be met.
15. STABILIZATION OF BED AND BANKS
The bed and banks of a watercourse shall be stabilized immediately after work in
the watercourse is completed.
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16. UNDERGROUND UTILITIES:
Underground utilities shall be installed in accordance with the following standards
in addition to other criteria:
a. No more than 500 linear feet of trench may be opened at one time.
b. Excavated material shall be placed on the uphill side of trenches
c. Effluent for dewatering operations shall be filtered or passed through approved
sediment trapping device, or both, and discharged in a manner that does not
adversely affect flowing streams or offsite property.
d. Material used for backfilling trenches shall be properly compacted in order to
minimize erosion and promote stabilization.
e. Restabilization shall be accomplished in accordance with these regulations.
f. Applicable safety regulations shall be complied with.
17. CONSTRUCTION ACCESS ROUTES:
Where construction vehicle access routes intersect paved public roads, provisions
shall be made to minimize the transport of sediment by vehicular tracking onto
paved surfaces. Where sediment is transported on to a public road surface, the
road shall be cleaned thoroughly at the end of each day. Sediment shall be
removed by shoveling or sweeping and transported to a sediment control disposal
area. Street washing shall be allowed only after sediment is removed in this
manner. This provision shall apply to individual Tots as well as to larger land
disturbing activities.
18. TEMPORARY E &S CONTROL MEASURE REMOVAL:
All temporary erosion and sediment control measures shall be removed within 30
days after final site stabilization or after temporary measures are no longer
needed, unless otherwise authorized by the local program authority. Trapped
sediment and the disturbed soil areas resulting from the disposition of temporary
measures shall be permanently stabilized to prevent further erosion and sediment.
19. ADEQUACY OF RECEIVING CHANNELS:
Properties and waterways downstream from the development site shall be
protected from sediment deposition, erosion and damage, due to increases in
volume, velocity and peak flow rates of stormwater runoff for the stated frequency
storm of 24 -hour duration.
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B1. PROJECT DESCRIPTION:
The purpose of this project is to construct Laurel Park Lane in Block C9 of
Hollymead Town Center. Laurel Park Lane will connect future portions of Meeting
Street and Timberwood Blvd. Total area of disturbance is 0.96 acres.
B2. EXISTING SITE CONDITIONS:
The site is currently vacant with existing deciduous brush and grass, on the
undisturbed portion.
B3. ADJACENT AREAS:
Commercial areas bound the property on all sides. Future Timberwood Blvd. and
Meeting Street are to the West and South.
B4. SOIL DESCRIPTIONS:
According to the Albemarle County Soils Survey conducted by the United States
Department of Agriculture Soil Conservation Service, the primary soil types that
may be disturbed during this scope of work and the primary soils that have been
placed from off -site borrow areas have been identified as the following:
1. Elioak Clay Loam, (28C3), 7 to 15 percent slopes
These soils are deep, strongly sloping, and well- drained. Permeability and
available water capacity are moderate. Surface runoff is rapid. The hazard
of erosion is severe, and past erosion has reduced the range of moisture
content for good workability. Hydrologic Group C soil, with a 0.28 K- Factor.
B5. CRITICAL AREAS:
There are no critical areas on this site.
B6. EROSION AND SEDIMENT CONTROL MEASURES:
Unless otherwise indicated, all erosion and sediment control practices will be
constructed and maintained according to the minimum standards and
specifications as set forth in the Virginia Erosion and Sediment Control Handbook,
latest edition. The minimum standards of the Virginia Erosion and Sediment
Control Regulations shall be adhered to unless otherwise waived or approved by
variance.
TEMPORARY CONSTRUCTION ENTRANCE (CE) — 3.02
An asphalt pad shall be constructed at the entrance of the project site to provide a
means of removing sediment from the tires of construction vehicles leaving the
work site. The Contractor shall remove any mud from the existing road surface by
means of sweeping and shoveling. A power washer and portable water supply will
be provided should the tracking of mud become a problem.
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DUST CONTROL (DC) — 3.39
A variety of methods are available to prevent surface and air movement of dust
from exposed soil surfaces and reduce the presence of airborne substances which
may present health hazards, traffic safety problems or harm animal or plant life.
SILT FENCE (SF) — 3.05
Silt fencing will be installed as a first step in construction activities. Location and
details are shown on the plans.
INLET PROTECTION (IP)
Block and gravel inlet protection, or wire mesh drop inlet protection shall be
constructed to prevent sediment laden runoff from entering the storm sewer
systems. Locations and details for the inlet protection are shown on the plans.
B7. PERMANENT AND TEMPORARY STABILIZATION:
SURFACE ROUGHENING — 3.29
Disturbed areas to be seeded and mulched shall be left in a roughened condition
to help decrease runoff velocities and aid in the establishment of vegetation.
TOPSOILING — 3.30
Topsoil may be stripped from the area to be graded and stockpiled for later use.
All stockpiles which will be left dormant for more than 30 days shall be temporarily
seeded. Topsoil stockpile location shall be coordinated with the County of
Albemarle Engineering Department, and shall be protected with silt fencing.
TEMPORARY SEEDING — 3.31
Temporary soil stabilization shall be applied within 4 days to denuded areas that
may not be at final grade, but will remain dormant (undisturbed) for longer than 30
days and less than 1 year. This includes, but is not limited to areas such as soil
stockpiles. Seeded areas shall be limed when necessary at a rate of 2 tons per
acre, and fertilized at a rate of 600 lbs. per acre of 10 -20 -20 (10 lbs. per 1,000
square feet) or equivalent. A Temporary Seeding Schedule is shown on the
attached plan.
PERMANENT SEEDING — 3.32
A perennial vegetative covering shall be established on disturbed areas within 4
days of being brought to final grade on areas not otherwise protected. Selection of
the seed mixture shall depend on the time of year it is to be applied according to
the Permanent Seed Schedule as shown on the drawing. Seeded areas shall be
limed when necessary at a rate of 2 tons per acres, and fertilized at a rate of 1,000
lbs. per acre of 10 -20 -10 (10 lbs. per 1,000 square feet) or equivalent.
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MULCHING — 3.35
All seeded areas shall be mulched with straw immediately following seeding
operations. Straw mulch shall be applied at a rate of two tons per acre.
SOIL STABILIZATION BLANKETS AND MATTING — 3.36
Soil stabilization matting shall be applied in the conveyance areas of the designed
diversions to help reduce velocities and aid in the establishment of vegetation. A
detail showing the proper materials and installation is shown on the plan.
B8. SOIL STOCKPILES AND BORROW AREAS
A soil stockpile shall be created on site if necessary.
B9. OFF -SITE ACTIVITIES
No offsite activities are proposed for this project.
B10. STORM WATER MANAGEMENT:
Stormwater management shall be provided by the stormwater facility currently
located at the intersection of Timberwood Blvd. and Route 29 South.
B11. MAINTENANCE SCHEDULE:
A program of maintenance for the erosion and sediment controls specified in this
narrative and shown on the plans are recommended as follows:
1. The contractor shall have a Responsible Land Disturber ( "RLD "), on the site
throughout the period during which the site is under construction. The "RLD" shall
maintain a daily erosion and sediment control log demonstrating that erosion and
sediment control measures are being closely monitored and deficiencies are
being quickly repaired. The "RLD" shall assure that all control measures are
being maintained in optimal condition. The log shall be made available for
inspection by the Program Authority at any time during regular business hours.
2. Prior to construction contractor shall schedule an on -site meeting with a flocculant
block supplier and site inspector to determine if the use of flocculants is
appropriate for the site and soil conditions.
3. The Site Superintendent or his representative shall make a visual inspection of all
erosion and sediment controls on a daily basis until the site is stabilized and
especially after a heavy rainfall to assure that all controls are in place and that
none have been damaged. Any damaged control shall be repaired prior to the end
of each workday to include reseeding if necessary.
5. Gravel outlets shall be checked regularly for sediment buildup that may prevent
drainage. Controls shall be inspected and repaired after each rainfall and cleaned
if sediment has accumulated to half of the device's original height.
6. All earthen structures such as diversion dikes and berms shall be checked daily
during construction for breaching by equipment. Repairs shall be made
immediately.
7. Silt fences shall be checked after each rainstorm to assure they have not fallen or
become clogged with silt. All repairs shall be made immediately.
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8. All seeded areas shall be inspected regularly to see that good stand is
maintained. Areas will be refertilized and reseeded as necessary.
9. After construction operations have ended and disturbed areas have been
stabilized, all berms and sediment - trapping devices may be removed. After
removal, the ground shal be restored to its natural or proposed condition to
include establishment of permanent vegetation. Removal of any control is
contingent upon approval of the County Inspector.
10. The developer shall reserve the right to install, maintain, remove and /or convert to
permanent stormwater management facilities (where applicable) all erosion
control measures required by this plan regardless of the sale of any lot.
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