HomeMy WebLinkAbout20070081 Ver 2_More Info Received_20070720 (2)KELLER ENVIRONMENTAL
ENVIRONMENTAL CONSULTANTS
7921 Haymarket Lane, Raleigh, NC
(919)844-7437
Fax (919)8447438
LETTER OF TRANSMITTAL
TO: NC Division of Water Quality
WE ARE SENDING YOU THE FOLLOWING:
^ Pre-construction Notification (PCN) ^ Plans
® Documents ^ Other
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DATE: July 20, 2007 ~~ ; ~ ~. ~ ~~ ~' al~,~ ~
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ATTENTION: DWQ EXPRESS TEAM `~`~~ ~ ~ d,:d
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RE: Cedar Ridge O & M Manual ~~~~'~:'~~~,~~~?'S~~~k c.~tJ~~i i~y°
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^ Maps ^ Specifications
THESE ARE TRANSMITTED AS CHECKED BELOW:
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COPIES DATE DESCRIPTION
1 Cedar Rid e O & M Manual
Remarks:
THANK YOU! ~a~
Recd By: Signed
STORMWATER
OPERATION & MAINTENANCE MANUAL
AND BUDGET
FOR BIO RETENTION AREAS
IN
CEDAR RIDGE SUBDIVISION
PHASES 2, 3, 4 & 5
Prepared by:
Aiken & Yelle Associates, PA
3755 Benson Drive
Raleigh, NC 27609
~.kp ~'1-no$t V~
OPERATIONS AND MAINTENACE MANUAL
SECTION I- INTRODUCTION:
This manual establishes procedures for maintenance and operation of stormwater in
accordance with the guidelines as set forth in the NCDWQ Stormwater Management
Design Manual. The NCDWQ rules require that stormwater devices be inspected
annually and that they be maintained in accordance with this document. Any repairs that
become necessary as a result of periodic inspections shall be completed within thirty (30)
calendar days of filing the report unless written approval of and extension is obtained
from the Town of Rolesville or NCDWQ.
The storm water management plan for this site consists of only water quality Bio
Retention areas. The Bio Retention areas are to serve as a bio-filtration to reduce the
nitrogen loading from the proposed impervious surface.
This development will be developed in four phases as approved by the Town of
Rolesville as depicted on the preliminary site plan on file in the Town of Rolesville
Planning Department. All phases 1 will be developed in accordance with construction
drawings entitled "Cedar Ridge Subdivision", prepared by Aiken & Yelle Associates,
PA, dated July 9, 2007 and approved by Town of Rolesville Central Engineering
Division. Therefore the water quality Bio Retention areas will also be installed by
phases. The Bio Retention areas to be constructed by phases are as follows:
A. Phase 2
Phase 2 of this development plan includes the construction of one (1) water quality
Bio Retention area as shown on the "Cedar Ridge Subdivision- Phase 2, 3, 4 and 5
Construction Drawings", prepared by this firm, dated 07/09/07.
Bio Retention area #1 will be constructed within a public drainage easement on Lot
111 of the proposed subdivision. More specifically the Bio Retention area will be
located down stream from storm sewer manhole #73. The Bio Retention surface area
required is be 800 SF (approx. 81 feet in length and 16 feet in width) with side slopes
of 3 (H): 1'(V) and a depth of 1 foot.
B. Phase 3
Phase 3 of this development plan includes the construction of one (1) water quality
Bio Retention area as shown on the "Cedar Ridge Subdivision- Phase 2, 3, 4 and 5
Construction Drawings", prepared by this firm, dated 07/09/07.
Bio Retention area #11 will be constructed on Lots 65 & 66 of the proposed
subdivision. More specifically the Bio Retention area will be located down stream
from storm sewer manhole #2 (SMH#2). The Bio Retention surface area required is
Page 2 of 14
1,100 SF (aprox. 50 feet in length and 28 feet in width) with side slopes of 3 (H):
1'(V) and a depth of 1 foot.
C. Phase 4
Bio Retention area #2 will be constructed within a designated open space area
proposed for this subdivision. More specifically the Bio Retention area will be
located down stream from storm sewer manhole #61B (SMH#61B). The Bio
Retention surface area will be 1,500 SF (approx. 62 feet in length and 35 feet in
width) with side slopes of 3 (H): 1'(V) and a depth of 1 foot.
Bio Retention area #3 will be constructed within a designated open space area
proposed for this subdivision. More specifically the Bio Retention area will be
located down stream from storm sewer manhole #64 (SMH#64). The Bio Retention
surface area will be 400 SF (approx. 38 feet in length and 12 feet in width) with side
slopes of 3 (H): 1'(V) and a depth of 1 foot.
Bio Retention area #4 will be constructed within a public drainage easement on Lot
100 of the subdivision. More specifically the Bio Retention area will be located down
stream from storm sewer manhole #57 (SMH#57). The Bio Retention surface area
will be 1,600 SF (approx. 140 feet in length and 12 feet in width) with side slopes of
3 (H): 1'(V) and a depth of 9 inches.
Bio Retention area #5 will be constructed within a public drainage easement on Lot
94 of the subdivision. More specifically the Bio Retention area will be located down
stream from storm sewer manhole #51 (SMH#51). The Bio Retention surface area
will be 1,000 SF (approx. 60 feet in length and 22 feet in width) with side slopes of 3
(H): 1'(V) and a depth of 1 foot. -
Bio Retention area #6 will be constructed within a public drainage easement on Lot
87 of the subdivision. More specifically the Bio Retention area will be located down
stream from storm sewer manhole #40 (SMH#40). The Bio Retention surface area
will be 600 SF (approx. 38 feet in length and 17 feet in width) with side slopes of 3
(H): 1'(V) and a depth of 1 foot.
Bio Retention area #7 will be constructed within a public drainage easement on Lot
80 of the subdivision. More specifically the Bio Retention area will be located down
stream from storm sewer manhole #33 (SMH#33). The Bio Retention surface area
will be 1,050 SF (approx. 56 feet in length and 24 feet in width) with side slopes of 3
(H): 1'(V) and a depth of 1 foot.
Bio Retention area #8 will be constructed within a public drainage easement on Lot
70 of the subdivision. More specifically the Bio Retention area will be located down
stream from storm sewer manhole #24 (SMH#24). The Bio Retention surface area
will be 1,300 SF (approx. 69 feet in length and 21 feet in width) with side slopes of 3
(H): 1'(V) and a depth of 1 foot.
Page 3 of 14
Bio Retention area #9 will be constructed within a designated open space area
proposed for this subdivision. More specifically the Bio Retention area will be
located down stream from storm sewer manhole #13 (SMH#13). The Bio Retention
surface area will be 675 SF (approx. 44 feet in length and 18 feet in width) with side
slopes of 3 (H): 1'(V) and a depth of 1 foot.
Bio Retention area #10 will be constructed within a designated open space area
proposed for this subdivision. More specifically the Bio Retention area will be
located down stream from storm sewer manhole #10 (SMH#10). The Bio Retention
surface area will be 400 SF (approx. 35 feet in length and 14 feet in width) with side
slopes of 3 (H): 1'(V) and a depth of 1 foot.
D. Phase 5
Bio Retention area #12 will be constructed within a public drainage easement on Lot
156 of the subdivision. More specifically the Bio Retention area will be located down
stream from storm sewer manhole #38 (SMH#38). The Bio Retention surface area
will be 625 SF (approx. 52 feet in length and 14 feet in width) with side slopes of 3
(H): 1'(V) and a depth of 1 foot.
SECTION II- WATER QUALITY BIO RETENTION AREA MAINTENANCE
REQUIREMENTS:
1. Watering: Plants should be selected to be tolerant of the bioretention facility's
particular conditions. Watering should not be required after establishment
(about 2 to 3 years). However, watering may be required during prolonged dry
periods after plants are established.
2. Erosion Control: Inspect flow entrances, ponding area, and surface overflow areas
periodically. Replace soil, plant material, and/or mulch in areas where erosion
has occurred. Erosion problems should not occur with proper design except
during extreme weather events. If erosion problems do occur, the following
issues should be re-assessed: flow volumes from the contributing drainage area
and bioretention size; flow velocities and gradients within the bioretention
facility; flow dissipation and erosion protection methods in the pretreatment and
in-flow areas. If sediment is deposited in the bioretention facility, immediately
determine the source, remove excess deposits, and correct the problem.
3. Plant Material: Depending on plants selected and aesthetic requirements,
occasional pruning and removal of dead plant material may be necessary.
Replace all dead plants. However, if specific plants consistently have a high
mortality rate, assess the cause and replace with appropriate species. Periodic
weeding is necessary until groundcover plants are established. Weeding should
become less frequent if an appropriate plant density has been used.
4. Nutrients and Pesticides: The soil media and plant material should have been
Page 4 of 14
selected for optimum fertility, plant establishment, and growth within the
particular conditions of each bioretention facility. Nutrient and pesticide inputs
should NOT be required and will degrade the pollutant processing capability of
the bioretention facility, as well as contribute to additional pollutant loading to
receiving waters. By design, bioretention facililities are typically specified in
watersheds where phosphorous and nitrogen levels are often elevated.
Therefore, these should not be limiting nutrients with regard to plant health. If
in question, have the soil analyzed for fertility.
5. Mulch: Replace mulch annually in bioretention facilities where heavy metal
deposition is likely (e.g., drainage areas that include commercial/industrial uses,
parking lots, or roads). In residential or other settings where metal deposition is
not a concern, replace or add mulch as needed to maintain a 2 to 4 inch depth at
least once every two years.
6. Soil media: Soil mixes for bioretention facilities are design to maintain long-term
fertility and pollutant processing capability. Estimates from metal attenuation
research indicates that metal accumulation should not present a toxicity concern
for at least 20 years in bioretention facilities (USEPA 2000). Further, replacing
mulch where heavy metal deposition is likely provides an additional factor of
safety for prolonged bioretention performance. If in question, have soil analyzed
for fertility and pollutant levels.
When the filtering capacity diminishes substantially (e.g., when water ponds on the
surface for more than 12 hours), remedial actions must be taken. One possible problem
is that underdrain pipe systems can become clogged. Annual flushing through pipe
cleanouts is recommended to facilitate unclogging of the pipes without disturbing the
bioretention areas. If the water still ponds for more than 12 hours, the top few inches of
material should be removed and replaced with fresh material. The removed sediments
should be disposed of in an acceptable manner (e.g., landfill). If that does not solve the
problem, more extensive rebuilding is required.
Examples of When to Perform Maintenance
Thin Mulch in the Bioretention Cell
^ Remove top layer of fill media when the pool does not drain quickly. The pool is
designed to drain within 12 hours.
Operation and Maintenance procedures:
- Immediately after the bioretention cell is established, the plants will be watered
twice weekly if needed until the plants become established (commonly six
weeks).
-Snow, mulch or any other material will NEVER be piled on the surface of the
bioretention cell.
-Heavy equipment will NEVER be driven over the bioretention cell.
-Special care will be taken to prevent sediment from entering the bioretention cell.
- Once a year, a soil test of the soil media will be conducted.
After the bioretention cell is established, I will inspect it once a month and within 24
Page 5 of 14
hours after every storm event greater than 1.0 inches. Records of inspection and
maintenance will be kept in a known set location
and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
~nsoection ana iviamtenance rrovisi~n5 ~u~ ~wiC~Ciiuvii r~~a~
BMP element Potential problems How to remediate the
roblem
The entire BMP Trash/debris is present Remove the trash/debris
The perimeter of the Areas of bare soil and/or Regrade the soil if
bioretention cell erosive gullies have necessary toremove the
formed. gully, and then plant
.aground cover and water
until it isestablished.
Provide lime and aone-
time fertilizer a lication.
The inlet device: pipe, zThe pipe is clogged (if Unclog the pipe. Dispose
stone verge or swale applicable). of the sediment off-site.
The pipe is cracked or
otherwise damaged (if
applicable).
Erosion is occurring in
the
swale (if applicable).
Stone verge is clogged or
covered in sediment (if
applicable)
Replace the pipe.
Regrade the swale if
necessary to smooth it
over and provide erosion
control devices such as
reinforced turf matting or
riprap to avoid future
problems with erosion.
Remove sediment and
clogged stone and
replace with clean stone.
_~:_. _
'ns ection and Maintenance Nrovisions for tsioretention Hreas c~nunueu
BMP element::: Potential problems How to remediate the
problem
Page 6 of 14
The pretreatment area Flow is bypassing Regrade if necessary to
pretreatment area route all flow to the
and/or gullies have pretreatment area.
formed. Restabilize the area
after radin
Sediment has Search for the source of
accumulated to a depth the sediment and
greater than three remedy the problem if
inches. possible. Remove the
sediment and restabilize
the retreatment area.
Erosion has occurred. Provide additional
erosion protection such
as reinforced turf
matting or riprap if
needed to prevent future
erosion roblems.
Weeds are present Remove the weeds,
preferably by hand.
The bioretention cell: Best professional Prune according to best
Vegetation practices professional
show that pruning is practices.
needed
to maintain optimal plant
health.
Plants are dead, Determine the source of
diseased or~ theproblem: soils,
dying. hydrology, disease, etc.
Remedy the problem
and replace plants.
Provide aone-time .
fertilizer application to
establish the ground
cover if a soil test
indicates it is necessa
Tree stakes/wires are Remove tree stake/wires
present (which can kill the tree if
six months after not removed).
plantin .
Page 7 of 14
The bioretention cell: Mulch is breaking down Spot mulch if there are
soils and mulch or only random void areas.
has floated away. Replace whole mulch
layer if necessary.
Remove the remaining
much and replace with
triple shredded hard
wood mulch at a
maximum depth of three
inches.
The bioretention cell: Soils and/or mulch are .Determine the extent of
soils and mulch clogged with .sediment. the clogging-remove and
replace either just the
top layers or the entire
media as needed.
Dispose of the spoil in
an appropriate off-site
location. Use triple
shredded hard wood
mulch at a maximum
depth of three inches.
Search for the source of
the sediment and
remedy the problem if
possible
An annual soil test Dolomitic lime shall be
shows that - applied as
pH has dropped or recommended per the
heavy soil test and toxic soils
metals have shall be removed,
accumulated in disposed of properly and
the soil media. replaced
with new lantin media.
The underdrain system Clogging has occurred Wash out the underdrain
(if applicable system
The drop inlet Clogging has occurred Clean out the drop inlet.
Dispose of the sediment
off-site.
The drop inlet is Repair or replace the
damaged drop inlet.
The receiving water Erosion or other signs of Contact the NC Division
damage have occurred of Water Quality 401
at the outlet. Oversight Unit at 919-
733-1786.
Page 8 of 14
SECTION V: OPERATION
A. Record Keeping
Operation of the storm water maintenance device should include recording of the
following:
• Annual Inspection Reports- Inspections should be conducted. A
professional engineer or his/her representative should conduct the
inspection. Reports should be kept on file with the Homeowner's
Association and a copy given to the Central Engineering Division of the
Town of Rolesville.
• Observations- All visual observations should be recorded. Where periodic
visual inspections are performed following significant rainfall events (2"
of rainfall in 24 hours or greater event), these inspections should be logged
into the Periodic Inspections, Operation & Maintenance Form in Section
X of this manual.
• Maintenance- Written reports of maintenance and/or repairs should be
recorded on the Periodic Inspections, Operation & Maintenance Form in
Section X of this manual.
B. Other Operational Procedures
The Owner's Association should maintain a complete and up-to-date set of plans
(as-built drawings) and all changes made to the storm water maintenance devices
over time should be recorded on the as-built plans.
SECTION VI: BUDGET
A. Annual Budget- Water Quality Bio Retention areas 1-12
Annual Inspection & Report
Registered Engineer 1 visit @ 8hrs/visit x $90/hour= $ 800.00
Miscellaneous Visits=
$ 500.00
Maintenance Cost for mowing, seeding fertilizing
And trash removal (2xs annual) $ 600.00
Sediment cost removal (every 5 years) annualized cost $ 600.00
Total Annual Budget (Water Quality Grass Lined Bio Retention areas=
$2,500.00
Page 9 of 14
Water Quality Grass Line Bio Retention
B, Total of Construction Cost for
areas.
Water ualit Bio Retention areas _ $ 72000.00
@ $6,000/peT _ $ 332.00
$ 0.501LF $ 72332.00
Bio Retention areas 12 =
664 LF Sub-total
Seedin
ter Quality Grass Line Bio Retention areas:
Total Constructio0n Cost for Wa
$72,332.0
of14
WATER QUALITY BIO RETENTION AREA INSPECTION CHECKLIST
CEDAR RIDGE SUBDIVISION SUBDIVISION
1NSPECTOR/(S): DATE:
WEATHER: TIME:
q WATER QUALITY BIO RETENTION AREA ACTION
U
~ aw.
v "'
x z
Ud
CHECK/CIRCLE
CONDITION NOTED
OBSERVATION
a
x
z
°z
x
aQ.
~
x
~
z
~ H
F
W
~
Bio Retention area # Location:
Vegetation
Erosion
Sediment
Trash
Bio Retention area # Location:
Vegetation
Erosion
Sediment
Trash
Bio Retention area # Location:
Vegetation/ cover
Erosion
Sediment
Trash
Bio Retention area # Location:
Vegetation/ cover
Erosion
Sediment
Trash
Bio Retention area # Location:
Vegetation/ cover
Erosion
Sediment
Trash
Bio Retention area # Location:
Vegetation/ cover
Erosion
Sediment
Trash
GENERAL COMMENTS, SKETCHES & FIELD MEASUREMENTS:
Page 11 of 14
CEDAR RIDGE SUBDIVISION SUBDIVISION
WATER QUALITY BIO RETENTION AREAS
PERIODIC INSPECTION, OPERTIAON AND MAINTENANCE REECORDS
RAIN WEATHER GENERAL
DATE TIME (in.) CONDITIONS OBSERVATIONS OR RECORDED BY
COMMENTS
DATE MAINTENANCE PERFORMED COMMENTS RECORDED BY
Page 12 of 14
MAINTENANCE AGREEMENT
Project: Cedar Ride Subdivision
Responsible Parry: Cedar Ridge Subdivision Homeowners' Association
Address: 8804 Albright Drive
Raleigh North Carolina
919-614-1733
I. Monthly Inspection-
A. Visual inspection for signs of erosion after cone-inch or more rainfall event
over a 24-hour period to determine if any appreciable damage occurred which
would require repair to the stormwater device.
B. Remove thrash and debris from inlets and outlets, emergency spillways and
Bio Retention areas.
II. Quarterly Inspections and Maintenance:
A. Same as the monthly described above.
III. Semi-Annually and Maintenance:
A. Same as quarterly inspection
B. Grassing and mowing as required. Mowing as needed when grass is over 8"
tall.
C. Reseed or re-vegetate disturbed vegetative areas.
IV. Annual Inspection and Maintenance:
A. Same as quarterly and semi-annual inspections.
B. Registered Engineer inspects and confirms that the stormwater devices are
operating properly and are in good physical condition. A copy of the
inspection reports in Section X of this report shall be submitted to the Central
Engineering Department of the Town of Rolesville. The date set as a deadline
to perform this annual inspection is one year after the date the as-built
drawings were first certified to the Town of Rolesville.
C. Sediment shall be removed if it is impeding the water flow..
Page 13 of 14
V. General Maintenance:
A. Mowing of Bio Retention areas according to the season. Maximum grass
height of 4-6 inches.
B. In case the ownership of the Impoundment transfers, the current owner shall
within thirty (30) days of transfer of ownership, notify the Town of Rolesville
Engineering Department, Stormwater Management Division of such
ownership transfer.
C. This property and impoundment is also subject to the Stormwater Operation
and Maintenance Manual and budget filed relative to this project.
D. All trash and debris removal should occur as needed. The pond should be
inspected for trash and debris monthly.
I, t2obert t~alc-nco ,for ~CdsC I~~d~a~t L,crrJC~e~~~+ne~F'll~ hereby
acknowledge that I, or my assigns, are the financially responsible party for
maintenance of these water quality Bio Retention areas. I or my assigns will perform
the maintenance as outlined in this document.
Signature: Date: 6
Company/Partnership: CCd4f ~tc~t ~..,~~ I~<,~I ~e~ t,LC
I, ~+b` ~ .. i D~ , a Notary Public for the State of GJdt~LP_ ,County
of ~y~~.~ L-,d,r„t ~„Q, do hereby certify that ~ ablfk 'Q e1 an G o Personally
appeared before me this day of , 20 0?, and acknowledge the due
execution of the foregoing instrument.
Witness my hand and official seal,
(SEAL)
KELLY E. PIERCE
NOTARY PUBLIC
WAKE COUNTY, N.C.
My Commission Expires 4-18-2012.
Notary
My commission expires ~ ' .~ 0102.,
Page 14 of 14