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HomeMy WebLinkAboutSW3180905_O&M Agreement/Plan_20210712Operation & Maintenance Agreement Project Name: Project Location: Twin Lakes Union County, 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 & cc Infiltration Basin Quantity: Infiltration Trench Quantity: Bioretention Cell Quantity: Wet Pond Quantity: Stormwater Wetland Quantity: Permeable Pavement Quantity: Sand Filter Quantity: Rainwater Harvesting Quantity: Green Roof Quantity: Level Spreader - Filter Strip Quantity: Proprietary System Quantity: Treatment Swale ��Yassed S�1iAIQ� Quantity: Dry Pond Quantity: Disconnected Impervious Surface Present: User Defined SCM Present: Low Density Present: nding O&M sheets will Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Location(s): Type: ne aaaeo automaucaii rner m 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: Title & Organization: Street address: City, state, zip: Phone number(s),: Dennis W. Moser, MAI President - Twin Lakes Farm, LLC 231 Post Office Drive, Suite B8 Indian Trail, NC 28079 704-576-0022 Idmoser@themosergroupinc.com Sign Cc Date: I, e4i � e �--� �— , a Notary Public for the State of v ty County of _61fA1,41c,/ , do hereby certify th �e�f) es Ztt - /;tc5&.,01 personally appeared before me this 1p — day of .�G�ly and ZO Z/ acknowledge the due execution of O erations and Maintenan Agreement. Witness my hand and official seal ert, RAENAE H NOTARY F Stanfy Q North Ca My commission Expi Sea! ITTLE Aprl! 16, 2022 My commission expires !Z- L6_ 2,Z STORM-EZ 7/2/2021 Version 1.5 O&M Agreement Page 1 of 9 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. 5CM 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 (if Unclog the pipe. Dispose of the sediment off -site. applicable). The inlet pipe is cracked The inlet device or otherwise damaged (if Repair or replace the pipe. 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 design depth for sediment location where it will not cause impacts to streams or the SCM. The forebay storage. 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. SCM element The main treatment area The vegetated shelf The embankment The outlet device Floating wetland island (if applicable) Wet Pond Maintenance Requirements (Continued) 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 design sediment storage location where it will not cause impacts to streams or the SCM. depth. Algal growth covers over Consult a professional to remove and control the algal growth. 50% of the area. Cattails, phragmites or Remove the plants by wiping them with pesticide (do not other invasive plants cover 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. 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. 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. gg g Clean out the outlet device and dispose of any sediment in a location where it will not cause impacts to streams or the SCM. The outlet device is Repair or replace the outlet device. damaged. Weeds or volunteer trees Remove the weeds or trees. are growing on the mat. The anchor cable is damaged, disconnected or Restore the anchor cable to its design state. missing. Wet Pond Maintenance Reauirements (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. Discharges from the wet The receiving water pond are causing erosion Contact the local NCDEQ Regional Office. or sedimentation in the receiving water. WET POND ID 1 Pretreatment other No than forebay? Has Veg. Filter? Yes Wet Detention Pond Design Summary Wet Pond Diagram FOREBAY Permanent Pool El. 628 Temporary Pool El: 629.62 Clean Out Depth: 6 Sediment Removal El 622 Bottom Elevation: 621 ATTACH ADDITIONAL SHEETS IF NECESSARY MAIN POND Permanent Pool El. 628 Temporary Pool El: 629.62 Clean Out Depth: 6 Sediment Removal El 622 Bottom Elevation: 621 Low Density Maintenance Requirements Important maintenance procedures: The drainage area to the vegetated conveyance or vegetated receiving area will be carefully managed to reduce the sediment load to the vegetated conveyance or vegetated receiving area. After the initial fertilization to establish the grass in the vegetated conveyance or the vegetated receiving area, fertilizer will not be applied to the vegetated receiving areas. The vegetated conveyance or vegetated receiving area will be inspected quarterly. 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. 5CM element: Potential problem: How to remediate the problem: Vegetation is too short or Maintain grassed vegetation such that the swale or vegetated Vegetation too long. area does not erode during the peak flow from the 10-year storm Trash/debris is present. Remove the trash/debris. Areas of bare soil and/or Regrade the soil if necessary to remove the gully, and then re - Vegetated receiving erosive gullies have sod (or plant with other appropriate species) and water until formed. established. Provide lime and a one-time fertilizer application. areas Trees and/or other woody Remove the trees and woody vegetation from the swale, vegetation are present in regrade the swale if necessary and re-establish grass as shown the swale. on the approved plans. Trash/debris is present. Remove the trash/debris. Areas of bare soil and/or Regrade the soil if necessary to remove the gully, and then re - erosive gullies have sod (or plant with other appropriate species) and water until formed. established. Provide lime and a one-time fertilizer application. Sediment covers the grass Remove sediment and dispose in an area that will not impact Vegetated conveyances / at the bottom of the swale. streams or SCMs. Re -sod if necessary. swales I roadside ditches (other than curb The side slope is steeper Regrade the slopes to the permitted configuration per the outlet swales) than the approved approved plan and reestablish vegetation. If as -built or existing configuration. conditions do not allow the slopes to be regraded, contact the applicable permitting agency. Determine the source of the problem: soils, hydrology, disease: Grass is dead, diseased or etc. Remedy the problem and replace plants. Provide a one - dying. time fertilizer application to establish the ground cover if necessary. Trees and/or other woody Remove the trees and woody vegetation from the vegetated vegetation are present in conveyance, regrade the vegetated conveyance if necessary the vegetated and re-establish grass as shown on the approved plans. ,conveyance. The longitudinal slope Regrade to meet the permitted longitudinal slope as shown on exceeds 5%. the approved plans. Curb outlet swales or The swale profile does not Regrade the swale to the approved profile as shown on the vegetated areas match the approved detail. approved plans. The length of the swale or Extend the swale to achieve the 100-foot minimum length. If as vegetated area is less built or existing conditions do not allow the slopes to be than 100 feet. regraded, contact the applicable permitting agency. Clogging has occurred. Clean out the outlet device. Dispose of the sediment off -site. The outlet device (if applicable) The outlet device is damaged Repair or replace the outlet device. Erosion or other signs of damage have occurred at Repair the damage and improve the flow dissipation structure. the outlet. Discharges from the site The receiving water are causing erosion or sedimentation in the Contact the local NCDEQ Regional Office. receiving water. Treatment Swale Maintenance Requirements Important operation and maintenance procedures: The drainage area of the grassed swale will be carefully managed to reduce the sediment load to the grassed swale. After the initial fertilization to establish the grass in the swale, fertilizer will not be applied to the treatment swale. The grassed swale will be inspected quarterly. 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. 5CM element: Potential problem: How to remediate the problem: Trash/debris is present. Remove the trash/debris. Areas of bare soil and/or Regrade the soil if necessary to remove the gully, re -sod (or erosive gullies have plant with other appropriate species) and water until formed. established. Provide lime and a one-time fertilizer application. Sediment covers the grass Remove sediment and dispose in an area that will not impact at the bottom of the swale. streams or SCMs. Re -sod if necessary. The entire length of the swale Vegetation is too short or too long. Maintain grassed vegetation such that the swale or vegetated area does not erode during the peak flow from the 10-year storm Determine the source of the problem: soils, hydrology, disease Grass is dead, diseased or etc. Remedy the problem and replace plants. Provide a one - dying. time fertilizer application to establish the ground cover if necessary. Trees and/or other woody Remove the trees and woody vegetation from the treatment vegetation are present in swale, regrade the treatment swale if necessary and re - the treatment swale. establish grass as shown on the approved plans. Clogging has occurred. Clean out the outlet device. Dispose of the sediment off -site. The outlet device (if The outlet device is damaged Repair or replace the outlet device. applicable) 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 treatment swale are causing erosion or Contact the local NCDEQ Regional Office. sedimentation in the receiving water.