SWA000109_Stormwater Report_20210707 (6)

STRONGROCK
L N G I N E L R I N G G R O U P
June 30, 2021
RE: Project name: Highland Ridge Subdivision
County: Wake
City: Angier
Address: Kennebec Road
Plan Type: New/Residential
State 1 Construction Sequence:
Strong Rock Engineering Group, PLLC
PO Box 99552
Raleigh, NC 27624
984.200.1932 (p)
Company License # P-2166
1. Obtain all approvals and permits necessary to begin and complete the project these approvals
and permits include, but are not limited to the following: subdivision approval, site design, zoning,
special use permit, etc, approval of designs for streets. Utilities, etc, erosion control plan approval
and grading permit, zoning compliance permit, driveway permit from ncdot. The approval and
permits must be obtained before the disturbance begins so that work will not be interrupted or
delayed due to the lack of approved plans.
2. Schedule and hold a pre -construction conference prior to beginning any land -disturbing
activities. This conference should be attended by a representative of the financially responsible
party and/or the general contractor, grading sub -contractor, erosion control sub -contractor.
3. Contractor to stake out the limit of disturbance and tree protection fencing. No disturbance is to
take place beyond the limit of work shown on the erosion control plan.
4. Clear the area necessary to gain access to and install the initial erosion control devices along the
perimeter of the site.
5. Clear and grub site and stockpile topsoil. Place silt fence around stockpiles.
6. Contractor to install temporary diversion berms and sediment basins per the sediment and
erosion control plan, initiate mass earthwork operations after all basins, berms, swales, silt fence
& other specified measures are installed.
7. Provide temporary groundcover for diversion ditches and sediment traps/basins within 3 days
of completion.
8. Temporary sediment basins and diversion berms and swales are to be constructed prior to each
phase of grading and modified as necessary to function.
9. Slopes are to be established as soon as practical before utility installation.
10. Contractor shall seed and stabilize all steep slopes (greater than 2h: Iv) within 7 days, 10 days
for moderate slopes (3h: Iv or greater) and within 14 calendar days everywhere else (state law
2009-486).
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11. Provide all disturbed areas with ground cover in accordance with note 910 after completion of
any phase of clearing, grubbing or grading, the seeding, seedbed preparation, mulch and/or rolled
erosion control product installation must be in accordance with the seeding schedule provided in
this s&e plan.
12. Temporary sediment basins shall be inspected at least once a week and within 24 hours of the
end of a storm with a rainfall amount of 1 inch or greater. Clean the sediment basin when sediment
accumulation exceeds one half the wet storage capacity of the basin or when the depth of available
pool is reduced to 18 inches, whichever is achieved first. Keep mud and debris off the public street
at all times. If mud or debris is tracked from the site use a shovel and broom to remove it
immediately. If mud and debris are not kept off the street, enforcement action (revoking the gracing
permit and/or a stop work order) may be taken.
13. Sediment and erosion controls shall be inspected at least once a week and within 24 hours of
the end of a storm with a rainfall amount of 1 inch or greater.
14. The sediment and erosion control plan shall be modified by the contractor at the direction of
the engineer and the city's designated representative as necessitated by changing site conditions.
If it is determined during the course of construction that significant sediment is leaving the site
despite proper implementation and maintenance of the approved erosion control plan, the person
responsible for the land -disturbing activity is obligated to take additional protective action.
15. The site should be kept clean of loose debris, litter, and building materials such that none of
these materials enter waters or wetlands.
16. After completion of any phase of clearing, grubbing or grading, land left exposed shall be
planted or otherwise provided with temporary ground cover, devices, or structures sufficient to
restrain erosion within the applicable time period according to note 910. The seeding, seedbed
preparation, mulch and/or rolled erosion control product installation must be in accordance with
the seeding schedule provided in this s&e plan
17. Construction will be phased and staged seeding and mulching will be utilized.
18. Contact the demlr Raleigh regional office at least 48 hours prior to commencing the land -
disturbing activity. The contact number is [phone]. (15 a ncac 04b.106(b))
19. "Erosion and sediment control (e&sc) permit and a certificate of coverage(coc) must be
obtained before any land disturbing activities occur." the coc can be obtained by filling out the
electronic notice of intent (e-noi) form at deq.nc.gov/ncg01. Please note, the e-noi form may only
be filled out once the plans have been approved. A copy of e&sc permit, the coc, and a hard copy
of the plan must be kept on site, preferably in a permit box, and accessible during inspection.
20. "When the project is complete, the permittee shall contact demlr to close out the e&sc plan."
after demlr informs the permittee of the project close out, via inspection report, the permittee shall
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visit deq.nc.gov/ncg01 to submit an electronic notice of termination(e-not). A $100 annual general
permit fee will be charged until the e-not has been filled out.
21. Contractor shall track the slopes.
22. "Perimeter measures must be left in place until all upland areas are permanently stabilized.
After site is permanently stabilized, remove all temporary erosion control measures and provide
permanent seeding where temporary measures have been removed and ground cover is not
adequate. Sediment basins may not be removed or converted to permanent bmps until all upland
areas are permanently stabilized."
23. "Per npdes requirements, a rain guage, self -inspection records, permit, certificate of coverage,
and s&e plan are required to be maintained on site and accessible during inspection. It is
recommended that these items be placed in a permit box at the beginning or entrance of project."
(ncg01 part iii sections a )
24. Dewatering at any basins shall be continuously monitored
25. Continue to stage 2.
State 2 Construction Sequence:
1. Continue mass grading from stage 1.
2. As the site is brought up to grade, the contractor shall raise and/or relocate all diversion ditches
to maintain a positive sediment laden flow to all sediment basins similarly, sediment basin
embankments shall be raised with grading activities if/and when necessary.
3. Install sanitary sewer system beginning at pump station and continuing upstream. At all stream
crossing locations, for installation of sanitary sewer, use the construction in the dry method. Place
the spoil stockpile on the upstream side of the trench during sanitary sewer installation.
4. Install storm collection system as site is brought to final grace beginning with main trunk lines
that convey runoff to the sediment basins.
5. Install approved inlet protection as inlets are installed temporary erosion control measures are
to remain until such measures have been approved for removal by the environmental engineer.
Additional measures may be required by the inspector to the routing of the storm drainage system
and field conditions.
6. Maintain erosion control measures weekly and after each rain event throughout construction.
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7. Stabilize graded areas as they are brought to final grade temporarily. Seed and mulch denuded
areas per the Durham county unified development ordinance sec. 12.10. 4(b).
8. As site areas are brought to final grade and stabilized and/or storm pipe collection system is
installed and conveys drainage to permanent basins, remove temporary sediment basins treating
those areas and the associated temporary diversion ditches. Call Durham country S&E office for
an inspection of site prior to removing temporary sediment basins and diversion ditches
9. Continue to stage 3
State 3 Construction Sequence:
1. Continue mass grading from stage 2.
2. At stream crossing locations, add silt fence above the top of the wall as shown on plan after the
wall is installed.
3. Complete installation of proposed storm pipe collection system. Install approved inlet protection
as inlets are installed.
4. As storm pipe collection system is completed, install the scm wet ponds with dimensions
modified for use during stage 3. Remove all other temporary sediment basins. Call ncdeq office
for an inspection of site prior to removing temporary sediment basins,
5. Maintain erosion control measures weekly and after each rain event throughout construction.
6. Stabilize graded areas as "they are brought to final grade. Temporarily seed and mulch denuded
areas per the Durham county unified development ordinance sec. 12.10.4(8).
7. As site areas are brought to final grade and stabilized convert scm's 1-5 to the scm wet ponds
with their permanent dimensions (per approved plans by ncdeq).
8. At the conclusion of building or if land -disturbing activity is stopped for more than 14
consecutive calendar days, permanent vegetative cover shall be installed in accordance with this
S&E plan.
9. Once site is stabilized request final approval by erosion control officer.
11. Construction will be phased and staged seeding and mulching will be utilized.
12. Contractor to dewater temporary basin prior to removal and /or conversion to a permanent
structure. Contractor to pump the water into the silt bag while dewatering the pond.
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13. Dewatering any basins shall be continuously monitored.
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