20190889 Ver 2_O&M Agreement_20191106

NNSWESTC OTT, SMALL
& AS SOCTATES
ENGINEERING I PLANNING I CONSULTING
RFC8,4eOIDENNDWR
NOV 0 6 2019
g* Rew11rces
Date: October 31, 2019
�ifting Sact"
To: Chonticha McDaniel From: Victoria Waldron Small, PE
Division of Water Resources Westcott, Small & Associates, PLLC
401 Stormwater Engineer 125 S. Elm Street, Suite 606
Greensboro,NC 2740
We are sending you® attached ❑ under separate cover the following items:
❑ Shop Drawings ❑ Estimate ❑ Disk
❑ Prints ❑ Specifications ® Other
❑ Contracts ❑ Copy of Letter
#COPIES I DRAWING NO DESCRIPTION DISPOSITION
I Operation & Maintenance For Your Use
Agreement or GSC Zoo
Expansion
REMARKS:
cc: File
125 S.Elm Street,Suite 606•Greensboro,North Carolina 27401 •phone:[phone] •web:www.wsaaeng.com
i

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A ,M

Operation & Maintenance Agreement
Project Name: Greensboro Science Center Zoo Expansion
Project Location: 4301 Lawndale Dr., Greensboro, NC
Cover Page
Maintenance records shall be kept on the following BMP(s). This maintenance record shall be kept in a log in a known set location.
Any deficient BMP elements noted in the inspection will be corrected, repaired, or replaced immediately. These deficiencies can
affect the integrity of structures,safety of the public,and the pollutant removal efficiency of the BMP(s).
The BMP(s)on this project include(check all that apply&corresponding O&M tables will be added automatically):
Bioretention Cell Quantity: 0 Location(s):
Dry Detention Basin Quantity: 0 Location(s):
Grassed Swale Quantity: 0 Location(s):
Green Roof Quantity: 0 Location(s):
Infiltration Basin Quantity: 0 Location(s):
Infiltration Trench Quantity: 0 Location(s):
Level SpreaderA/FS Quantity: 1 Location(s): STP-100 at Flamingo Building
Permeable Pavement Quantity: 0 Location(s):
Proprietary System Quantity: 0 Location(s):
Rainwater Harvesting Quantity: 0 Location(s):
Sand Filter Quantity: 0 Location(s):
Stormwater Wetland Quantity:RNo
Location(s):
Wet Detention Basin Quantity: Location(s):
Disconnected Impervious Area Present: Location(s):
User Defined BMP Present: Location(s):
I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed for
each BMP above, and attached O&M tables. I agree to notify NCDENR of any problems with the system or prior to any changes to
the system or responsible party.
'Responsible Parry: Butch Shumate
Title&Organization: Facililties Manager City of Greensboro
Street address: PO Box 3136
City,state, zip: Greensboro, NC 27402
Phone number(s): 336-412-5794
Email: [e-mail]
Signature: trCCa.4 Date:
I, )e r I Ru firc�r,d a a rd— a Notary Public for the State of d(+K O!j rw
County of C?1.t l Grd do hearby certify that �U,ILL►VGk 5ku MkiLTe-
personally appeared before me this 3��� day of Dch Ix r and
acknowledge the due execution of the
/O�perations/aril Maaiin-tenance A r ement .
Witness my hand and official seal,
�DTARy
— o.wiaa —
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Seal ///llltl\\\ My commission expires
STORM-EZ 9/23/2019
Version 1.4 O&M Manual Page 1 of 3

Level Spreader-Vegetated Filter Strip/Restored Riparian Buffer Maintenance Requirements
Important maintenance procedures:
Immediately after the filter strip is established, any newly planted vegetation will be watered twice weekly if
needed until the plants become established (commonly six weeks).
- Once a year,the filter strip will be reseeded to maintain a dense growth of vegetation
- Stable groundcover will be maintained in the drainage area to reduce the sediment load to the vegetation.
Two to three times a year, grass filter strips will be mowed and the clippings harvested to promote the growth of
thick vegetation with optimum pollutant removal efficiency.Turf grass should not be cut shorter than 3 to 5 inches
and may be allowed to grow as tall as 12 inches depending on aesthetic requirements (NIPC, 1993). Forested
filter strips do not require this type of maintenance.
- Once a year,the soil will be aerated if necessary.
- Once a year,soil pH will be tested and lime will be added if necessary.
After the filter strip is established, it will be inspected quarterly and within 24 hours after every storm event greater than 1.0 inch
(or 1.5 inches if in a Coastal County). Records of operation 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.
BMP element: Potentialproblem: How to remediate theproblem:
The entire BMP Trash/debris is present. Remove the trash/debris.
The perimeter of the BMP Areas of bare soil and/or Regrade the soil if necessary to remove the gully,and then plant a
erosive gullies have formed. ground cover and water until it is established. Provide lime and a one-
time fertilizer application.
Vegetation is too short or too Maintain vegetation at a height of approximately six inches.
long.
The flow splitter device(if The flow splitter device is Unclog the conveyance and dispose of any sediment off-site.
applicable) clogged.
The flow splitter device is Make any necessary repairs or replace if damage is too large for repair.
damaged.
The inlet device The pipe is clogged. Unclog the pipe. Dispose of the sediment off-site.
The pipe is cracked or Replace the pipe.
otherwise damaged.
Erosion is occurring in the Regrade the swale if necessary to smooth it over and provide erosion
swale. control devices such as reinforced turf matting or riprap to avoid future
problems with erosion.
Stone verge is clogged or Remove sediment and replace with clean stone.
covered in sediment(if
applicable).
I
STORM-EZ 9/2 312 01 9
Version 1.4 O&M Manual Page 2 of 3

LS-VFS/Restored Riparian Buffer Maintenance Requirements(Continued)
The swale and the level lip The swale is clogged with Remove the sediment and dispose of it off-site.
sediment.
The level lip is cracked, Repair or replace lip.
settled, undercut,eroded or
otherwise damaged.
There is erosion around the Regrade the soil to create a berm that is higher than the level lip, and
end of the level spreader that then plant a ground cover and water until it is established. Provide lime
shows stormwater has and a one-time fertilizer application.
bypassed it.
Trees or shrubs have begun tc Remove them.
grow on the swale or just
downslope of the level lip.
The bypass channel Areas of bare soil and/or Regrade the soil if necessary to remove the gully,and then reestablish
erosive gullies have formed. proper erosion control.
Turf reinforcement is Study the site to see if a larger bypass channel is needed (enlarge if
damaged or ripap is rolling necessary). After this, reestablish the erosion control material.
downhill.
The filter strip Grass is too short or too long Maintain grass at a height of approximately three to six inches.
(if applicable).
Areas of bare soil and/or Regrade the soil if necessary to remove the gully,and then plant a
erosive gullies have formed. ground cover and water until it is established. Provide lime and a one-
time fertilizer application.
Sediment is building up on the Remove the sediment and restabilize the soil with vegetation if
filter strip. necessary. Provide lime and a one-time fertilizer application.
Plants are desiccated. Provide additional irrigation and fertilizer as needed.
Plants are dead, diseased or Determine the source of the problem: soils, hydrology, disease, etc.
dying. Remedy the problem and replace plants. Provide a one-time fertilizer
application.
Nuisance vegetation is Remove vegetation by hand if possible. If pesticide is used, do not
choking out desirable species. allow it to get into the receiving water.
The receiving water Erosion or other signs of Contact the NCDENR local Regional Office, or the 401 Oversight Unit
damage have occurred at the at 919-733-1786.
outlet.
STORM-EZ 9/2 312 0 1 9
Version 1.4 O&M Manual Page 3 of 3