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HomeMy WebLinkAboutSW3231001_O&M Agreement/Plan_20231219 Operation & Maintenance Agreement Project Name: McBride Subdivision Project Location: Hemby Bridge, North Carolina Cover Page Maintenance records shall be kept on the following SCM(s). This maintenance record shall be kept in a log in a known set location. Any deficient SCM 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 SCM(s). The SCM(s) on this project include (check all that apply & corresponding O&M sheets will be added automatically): Infiltration Basin Quantity: Location(s): Infiltration Trench Quantity: Location(s): Bioretention Cell Quantity: Location(s): Wet Pond Quantity: 1 Location(s): N: 499525.56 ; E: 1508098.59 Stormwater Wetland Quantity: Location(s): Permeable Pavement Quantity: Location(s): Sand Filter Quantity: 1 Location(s): N: 499408.77 ; E: 1509311.42 Rainwater Harvesting Quantity: Location(s): Green Roof Quantity: Location(s): Level Spreader - Filter Strip Quantity: Location(s): Proprietary System Quantity: Location(s): Treatment Swale Quantity: Location(s): Dry Pond Quantity: Location(s): Disconnected Impervious Surface Present: No Location(s): User Defined SCM Present: No Location(s): Low Density Present: No Type: I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed for each SCM above, and attached O&M tables. I agree to notify NCDEQ of any problems with the system or prior to any changes to the system or responsible party. Responsible Party: Scott Widener Title & Organization: Division President, DRB Group NC, LLC Street address: 227 West Trade St, Ste 400 City, state, zip: Charlotte, NC, 28202 Phone number(s): 704-200-9730 Email: swidener@drbgroup.com Signature: Date: I, , a Notary Public for the State of County of , do hereby certify that personally appeared before me this day of and acknowledge the due execution of the Operations and Maintenance Agreement . Witness my hand and official seal, Seal My commission expires STORM-EZ 8/22/2023 Version 1.5 O&M Agreement Page 1 of 7 Wet Pond Maintenance Requirements Important operation and maintenance procedures: Immediately after the wet detention basin is established, the plants on the vegetated shelf and - perimeter of the basin should be watered twice weekly if needed, until the plants become established (commonly six weeks). No portion of the wet pond should be fertilized after the initial fertilization that is required to establish - the plants on the vegetated shelf. _ Stable groundcover will be maintained in the drainage area to reduce the sediment load to the wet pond. If the pond must be drained for an emergency or to perform maintenance, the flushing of sediment - through the emergency drain will be minimized as much as possible. _ At least once annually, a dam safety expert will inspect the embankment. Any problems that are found will be repaired immediately. The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. After the wet pond is established, it will be inspected quarterly and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance shall be kept in a known set location and shall be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. SCM element: Potential problem: How to remediate the problem: The entire wet pond Trash/debris is present. Remove the trash/debris. The perimeter of the wet Areas of bare soil and/or Regrade the soil if necessary to remove the gully, plant ground pond erosive gullies have cover and water until it is established. Provide lime and a one- formed. time fertilizer application. The inlet pipe is clogged Unclog the pipe. Dispose of the sediment off-site. (if applicable). The inlet pipe is cracked or otherwise damaged (if Repair or replace the pipe. The inlet device applicable). Erosion is occurring in the Regrade the swale if necessary and provide erosion control swale (if applicable). devices such as reinforced turf matting or riprap to avoid future problems with erosion. Sediment has accumulated to a depth Search for the source of the sediment and remedy the problem greater than the original if possible. Remove the sediment and dispose of it in a location design depth for sediment where it will not cause impacts to streams or the SCM. storage. The forebay Erosion has occurred. Provide additional erosion protection such as reinforced turf matting or riprap if needed to prevent future erosion problems. Weeds are present. Remove the weeds, preferably by hand. If pesticide is used, wipe it on the plants rather than spraying. Wet Pond Maintenance Requirements (Continued) SCM element: Potential problem: How to remediate the problem: Sediment has accumulated to a depth Search for the source of the sediment and remedy the problem greater than the original if possible. Remove the sediment and dispose of it in a location design sediment storage where it will not cause impacts to streams or the SCM. depth. The main treatment area Algal growth covers over Consult a professional to remove and control the algal growth. 50% of the area. g Cattails, phragmites or other invasive plants cover Remove the plants by wiping them with pesticide (do not spray). 50% of the basin surface. Best professional practices show that pruning is needed to Prune according to best professional practices. maintain optimal plant health. The vegetated shelf Determine the source of the problem: soils, hydrology, disease, Plants are dead, diseased etc. Remedy the problem and replace plants. Provide a one- or dying. time fertilizer application to establish the ground cover if a soil test indicates it is necessary. Weeds are present. Remove the weeds, preferably by hand. If pesticide is used, wipe it on the plants rather than spraying. Shrubs have started to Remove shrubs immediately. grow on the embankment. Evidence of muskrat or Consult a professional to remove muskrats or beavers and beaver activity is present. repair any holes or erosion. The embankment A tree has started to grow Consult a dam safety specialist to remove the tree. on the embankment. An annual inspection by an appropriate professional shows that Make all needed repairs immediately. the embankment needs repair. Clogging has occurred. Clean out the outlet device and dispose of any sediment in a gg g location where it will not cause impacts to streams or the SCM. The outlet device The outlet device is damaged. Repair or replace the outlet device. Weeds or volunteer trees Remove the weeds or trees. are growing on the mat. Floating wetland island (if applicable) The anchor cable is damaged, disconnected or Restore the anchor cable to its design state. missing. Wet Pond Maintenance Requirements (Continued) SCM element: Potential problem: How to remediate the problem: Erosion or other signs of damage have occurred at Repair the damage and improve the flow dissipation structure. the outlet. The receiving water Discharges from the wet pond are causing erosion Contact the local NCDEQ Regional Office. or sedimentation in the receiving water. Wet Detention Pond Design Summary Wet Pond Diagram WET POND ID FOREBAY MAIN POND BMP 1 Permanent Pool El. 636.5 1 Permanent Pool El. 636.5 Temporary Pool El: 637.27 Temporary Pool El: 627.7 Pretreatment other Clean Out Depth: 5.5 Clean Out Depth: 5.5 than forebay? No Sediment Removal El 631 Sediment Removal El 631 Has Veg. Filter? No Bottom Elevation: 630 Bottom Elevation: 630 ATTACH ADDITIONAL SHEETS IF NECESSARY Sand Filter Maintenance Requirements Important operation and maintenance procedures: - Manage the drainage area to reduce the sediment load to the sand filter. - Clean out the sedimentation chamber or forebay whenever sediment depth exceeds six inches. - At least once a year, skim the sand media - Replace the sand filter media whenever it fails to function properly after maintenance. After the sand filter is established, it shall be inspected quarterly and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance shall be kept in a known set location and shall be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. SCM element: Potential problem: How to remediate the problem: Entire sand filter Trash/debris is present. Remove the trash/debris. Adjacent pavement (if Sediment is present on the Sweep or vacuum the sediment as soon as possible. applicable) pavement surface. Areas of bare soil and/or Regrade the soil if necessary to remove the gully, plant ground erosive gullies have cover and water until it is established. Provide lime and a one- The perimeter of the sand formed. time fertilizer application. filter Vegetation is too short or Maintain vegetation at an appropriate height. too long. The structure is clogged. Unclog the structure and dispose of sediment in a location where The flow diversion it will not cause impacts to streams or the SCM. structure (if applicable) Make any necessary repairs or replace if the damage is too much The structure is damaged. for repair. The inlet pipe is clogged (if Unclog the pipe and dispose of sediment in a location where it applicable). will not cause impacts to streams or the SCM. The inlet pipe is cracked or otherwise damaged (if Repair or replace the pipe. applicable). The inlet device Regrade the swale if necessary and provide erosion control Erosion is occurring in the devices such as reinforced turf matting or riprap to avoid future swale (if applicable). problems with erosion. Stone verge is clogged or Remove sediment and clogged stone and replace with clean covered in sediment (if applicable). stone. Sediment has accumulated Search for the source of the sediment and remedy the problem if to a depth of greater than possible. Remove the sediment and dispose of it in a location six inches. where it will not cause impacts to streams or the SCM. Sediment chamber (forebay) Provide additional erosion protection such as reinforced turf Erosion has occurred. matting or riprap if needed to prevent future erosion problems. Weeds are present. Remove the weeds, preferably by hand. If a pesticide is used, wipe it on the plants rather than spraying. Sand Filter Maintenance Requirements (continued) SCM element: Potential problem: How to remediate the problem: Sand chamber and Water is ponding on the Check to see if the collector system is clogged and flush if underdrain collection surface for more than 24 necessary. If water still ponds, remove the top few inches of filter system hours after a storm. bed media and replace. If water still ponds, then consult an appropriate professional. Clogging has occurred. Clean out the outlet device and dispose of sediment in a location gg g where it will not cause impacts to streams or the SCM. The outlet device The outlet device is Repair or replace the outlet device. damaged. Erosion or other signs of damage have occurred at Repair the damage and improve the flow dissipation structure. the outlet. The receiving water Discharges from the sand filter are causing erosion or Contact the local NCDEQ Regional Office. sedimentation in the receiving water.