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HomeMy WebLinkAboutNCS000429_MS4 Operation and Maintenance Plan Draft_20220224Wit- W CIASTONI NC �i-ctitPlace. G;vt tPeople. "c° ,:rrPromise. Municipal Separate Storm Sewer Operation and Maintenance Plan Draft Description This plan serves as guide for maintaining the operation of post constructed Stormwater Control Measures (SCMs) on sites that are required to meet stormwater controls as determined by Section 14 of the City of Gastonia's MuniCode. All designs for SCMs are to follow the latest NC Stormwater Design Manual as provided by NC Department of Environmental Quality. The As -Built documents provided once construction of the SCMs are complete should also contain the Operation and Maintenance of plan for any and all SCMs (and best management practices) associated with maintaining the Stormwater Control Measures. Inspection Procedure and Authority Site inspections should be conducted regularly throughout the year to ensure that SCM is functioning during various climatic occurrences. Outcome reports should be provided to the manager or owner of each SCM and should be held on site to ensure the integrity of the SCM is maintained. 3rd party reports are encouraged, as a good faith effort by the site manager, but official inspections are to be performed by staff who have received certification through NC State Universities SCM Maintenance and Inspection program and are in good standing. The following forms provided by NCSU are to be used as the the appropriate method to inspect and manage the SCMs on each site. Additional Considerations When performing inspections, it is also pertinent to examine the inlets, outlets and drainage area to the SCMs. To ensure that the most effective maintenance is being considered, it is also important to ensure that no additional contributions of impacts are accelerating the maintenance frequency, there by impairing the overall function of the SCM. SCM Inspection & Maintenance Forms Table of Contents Bioretention Inspection and Maintenance Agreement................................................................. Page 1 Dry Extended Detention Basin Inspection and Maintenance Agreement .................................. Page 5 Filter Strip, Restored Riparian Buffer and Level Spreader I & M Agreement ............................. Page 9 Permeable Pavement Inspection and Maintenance Agreement ................................................. Page 12 Sand Filter Inspection and Maintenance Agreement.................................................................... Page 15 Stormwater Wetland Inspection and Maintenance Agreement ................................................. Page 18 Wet Detention Basin Inspection and Maintenance Agreement .................................................. Page 22 These forms are available on-line at: https://deg.nc.gov/about/divisions/energy-mineral-land-resources/ energy-mineral-land-permit-guidance/stormwater-bmp-manual/forms Permit Number: (to be provided by DWQ) Drainage Area Number: Bioretention Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will 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 removal efficiency of the BMP. Important 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 hours after every storm event greater than 1.0 inches (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: Potentialproblems: How I will remediate theproblem: 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 necessary to bioretention cell erosive gullies have formed. remove the gully, and then plant a ground cover and water until it is established. Provide lime and a one-time fertilizer application. The inlet device: pipe, The pipe is clogged (if Unclog the pipe. Dispose of the stone verge or swale applicable). sediment off -site. The pipe is cracked or Replace the pipe. otherwise damaged (if applicable). Erosion is occurring in the Regrade the swale if necessary to swale (if applicable). smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid future problems with erosion. Stone verge is clogged or Remove sediment and clogged covered in sediment (if stone and replace with clean stone. applicable). Form SW401-Bioretention O&M-Rev.3 Page 1 of 4 BMP element: Potentialproblems: How I will remediate theproblem: The pretreatment area Flow is bypassing Regrade if necessary to route all pretreatment area and/or flow to the pretreatment area. gullies have formed. Restabilize the area after grading. Sediment has accumulated to Search for the source of the a depth greater than three sediment and remedy the problem if inches. possible. Remove the sediment and restabilize the pretreatment area. 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. The bioretention cell: Best professional practices Prune according to best professional vegetation show that pruning is needed practices. to maintain optimal plant health. Plants are dead, diseased or Determine the source of the dying. problem: soils, hydrology, disease, etc. Remedy the problem and replace plants. Provide a one-time fertilizer application to establish the ground cover if a soil test indicates it is necessary. Tree stakes/wires are present Remove tree stake/wires (which six months after planting. can kill the tree if not removed). The bioretention cell: Mulch is breaking down or Spot mulch if there are only random soils and mulch has floated away. void areas. 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. Soils and/or mulch are Determine the extent of the clogging clogged with sediment. - 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 shows that Dolomitic lime shall be applied as pH has dropped or heavy recommended per the soil test and metals have accumulated in toxic soils shall be removed, the soil media. disposed of properly and replaced with new planting media. Form SW401-Bioretention O&M-Rev.3 Page 2 of 4 BMP element: Potentialproblems: How I will remediate theproblem: The underdrain system Clogging has occurred. Wash out the underdrain system. (if applicable) The drop inlet Clogging has occurred. Clean out the drop inlet. Dispose of the sediment off -site. The drop inlet is damaged Repair or replace the drop inlet. The receiving water Erosion or other signs of Contact the NC Division of Water damage have occurred at the Quality 401 Oversight Unit at 919- outlet. 733-1786. Form SW401-Bioretention O&M-Rev.3 Page 3 of 4 Permit Number: (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Project name: BMP drainage area number: Print name: Title: Address: Phone: Signature: Date: Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. 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 forgoing bioretention maintenance requirements. Witness my hand and official seal, SEAL My commission expires Form SW401-Bioretention 1&M-Rev. 2 Page 4 of 4 Permit Number: (to be provided by DWQ) Drainage Area Number: Dry Extended Detention Basin Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will 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 removal efficiency of the BMP. The dry extended detention basin system is defined as the dry detention basin, outlet structure, pretreatment including forebays and the vegetated filter if one is provided. This system (check one): ❑ does ❑ does not incorporate a vegetated filter at the outlet. This system (check one): ❑ does ❑ does not incorporate pretreatment other than a forebay. Important maintenance procedures: — The drainage area will be managed to reduce the sediment load to the dry extended detention basin. — Immediately after the dry extended detention basin is established, the vegetation will be watered twice weekly if needed until the plants become established (commonly six weeks). — No portion of the dry extended detention pond will be fertilized after the first initial fertilization that is required to establish the vegetation. — I will maintain the vegetation in and around the basin at a height of approximately six inches. — Once a year, a dam safety expert will inspect the embankment. After the dry extended detention basin is established, it will be inspected once a quarter 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 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 I will remediate theproblem: The entire BMP Trash/ debris is present. Remove the trash/ debris. The perimeter of the dry Areas of bare soil and/or Regrade the soil if necessary to extended detention erosive gullies have formed. remove the gully, and then plant a basin ground cover and water until it is established. Provide lime and a one-time fertilizer application. Form SW401-Dry Detention O&M-Rev.3 Page 1 of 4 BMP element: Potentialproblem: How I will remediate theproblem: The inlet device: pipe or The pipe is clogged (if Unclog the pipe. Dispose of the swale applicable). sediment off -site. The pipe is cracked or Replace the pipe. otherwise damaged (if applicable). Erosion is occurring in the Regrade the swale if necessary to swale (if applicable). smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid future problems with erosion. The forebay Sediment has accumulated Search for the source of the and reduced the depth to 75% sediment and remedy the problem if of the original design depth possible. Remove the sediment and (see diagram below). dispose of it in a location where it will not cause impacts to streams or the BMP. Erosion has occurred or Provide additional erosion riprap is displaced. protection such as reinforced turf matting or riprap if needed to revent future erosion problems. Weeds are present. Remove the weeds, preferably by hand. If pesticides are used, wipe them on the plants rather than spraying. The main treatment area Sediment has accumulated Search for the source of the and reduced the depth to 75% sediment and remedy the problem if of the original design depth possible. Remove the sediment and (see diagram below). dispose of it in a location where it will not cause impacts to streams or the BMP. Revegetate disturbed areas immediately with sod (preferred) or seed protected with securely staked erosion mat. Water is standing more than Check outlet structure for clogging. 5 days after a storm event. If it is a design issue, consult an appropriate rofessional. Weeds and noxious plants are Remove the plants by hand or by growing in the main wiping them with pesticide (do not treatment area. spray). Form SW401-Dry Detention O&M-Rev.3 Page 2 of 4 BMP element: Potentialproblem: How I will remediate theproblem: The embankment Shrubs or trees have started Remove shrubs or trees to grow on the embankment. immediately. Grass cover is unhealthy or Restore the health of the grass cover eroding. - consult a professional if necessary. Signs of seepage on the Consult a professional. downstream face. Evidence of muskrat or Use traps to remove muskrats and beaver activity is present. consult a professional to remove beavers. An annual inspection by an Make all needed repairs. appropriate professional shows that the embankment needs repair. The outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment off -site. The outlet device is damaged Repair or replace the outlet device. The receiving water Erosion or other signs of Contact the NC Division of Water damage have occurred at the Quality 401 Oversight Unit at 919- outlet. 733-1786. 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. When the basin depth reads When the basin depth reads Sediment Removal feet in the main pond, the sediment shall be removed. feet in the forebay, the sediment shall be removed. BASIN DIAGRAM ill in the blanks) --------------T- m plue, Bottom Elevatioi 25 /o Sediment Storage FOREBAY Temporary Pool Elevation Pool emP D ora Sediment Removal Elevation Volume Bottom Elevation 1 25% MAIN POND Form SW401-Dry Detention O&M-Rev.3 Page 3 of 4 Permit Number: (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Project name: BMP drainage area number: Print name: Title: Address: Phone: Signature: Date: Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. 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 forgoing dry detention basin maintenance requirements. Witness my hand and official seal, SEAL My commission expires Form SW401-Dry Detention O&M-Rev.3 Page 4 of 4 Permit Number: (to be provided by DWQ) Drainage Area Number: Filter Strip, Restored Riparian Buffer and Level Spreader Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will 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 removal efficiency of the BMP. 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 I will remediate theproblem: The entire filter strip Trash/ debris is present. Remove the trash/ debris. system The flow splitter device The flow splitter device is Unclog the conveyance and dispose (if applicable) clogged. of anysediment off -site. The flow splitter device is Make any necessary repairs or damaged. replace if damage is too large for repair. Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 1 of 3 BMP element: Potentialproblem: How I will remediate theproblem: The Swale and the level The swale is clogged with Remove the sediment and dispose lip sediment. of it off -site. 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 end of the level spreader that that is higher than the level lip, and shows stormwater has then plant a ground cover and bypassed it. water until it is established. Provide lime and a one-time fertilizer application. Trees or shrubs have begun Remove them. to grow on the swale or just downslo e of the level lip. The bypass channel Areas of bare soil and/or Regrade the soil if necessary to erosive gullies have formed. remove the gully, and then reestablish proper erosion control. Turf reinforcement is Study the site to see if a larger damaged or ripap is rolling bypass channel is needed (enlarge if downhill. necessary). After this, reestablish the erosion control material. The filter strip Grass is too short or too long Maintain grass at a height of if applicable). approximately three to six inches. Areas of bare soil and/or Regrade the soil if necessary to erosive gullies have formed. remove the gully, and then plant a ground cover and water until it is established. Provide lime and a one-time fertilizer application. Sediment is building up on Remove the sediment and the filter strip. restabilize the soil with vegetation if 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 dying. problem: soils, hydrology, disease, etc. Remedy the problem and replace plants. Provide a one-time fertilizer application. Nuisance vegetation is Remove vegetation by hand if choking out desirable species. possible. If pesticide is used, do not allow it to get into the receiving water. The receiving water Erosion or other signs of Contact the NC Division of Water damage have occurred at the Quality local Regional Office, or the outlet. 401 Oversight Unit at 919-733-1786. Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 2 of 3 Permit Number: (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Project name: BMP drainage area number: Print name: Title: Address: Phone: Signature: Date: Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. 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 forgoing filter strip, riparian buffer, and/or level spreader maintenance requirements. Witness my hand and official seal, SEAL My commission expires Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 3 of 3 Permit Number: (to be provided by DWQ) Drainage Area / Lot Number: Permeable Pavement Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will 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 removal efficiency of the BMP. Important operation and maintenance procedures: — Stable groundcover will be maintained in the drainage area to reduce the sediment load to the permeable pavement. — The area around the perimeter of the permeable pavement will be stabilized and mowed, with clippings removed. — Any weeds that grow in the permeable pavement will be sprayed with pesticide immediately. Weeds will not be pulled, since this could damage the fill media. — Once a year, the permeable pavement surface will be vacuum swept. — At no time shall wet sweeping (moistening followed by sweeping) be allowed as a means of maintenance. — There shall be no repair or treatment of Permeable Pavement surfaces with other types of pavement surfaces. All repairs to Permeable Pavement surfaces must be accomplished utilizing permeable pavement which meets the original pavement specifications. — Concentrated runoff from roof drains, piping, swales or other point sources, directly onto the permeable pavement surface shall not be allowed. These areas must be diverted away from the permeable pavement. Initial Inspection: Permeable Pavements shall be inspected monthly for the first three months for the following: BMP element: Potentialproblem: How to remediate theproblem: The perimeter of Areas of bare soil and/or In the event that rutting or failure of the groundcover the permeable erosive gullies have occurs, the eroded area shall be repaired immediately pavement formed. and permanent groundcover re-established. Appropriate temporary Erosion Control measures (such as silt fence) shall be installed in the affected area during the establishment of permanent groundcover, and any impacted area of permeable pavement is to be cleaned via vacuum sweeping. The surface of the Rutting / uneven This indicates inadequate compaction of the pavement permeable settlement base / sub -base. If rutting or uneven settlement on the pavement order of'h inch or greater occurs, permeable pavement shall be removed and base / sub -base re -compacted, smoothed, and permeable pavement shall then be re- installed. Base and sub -base compaction shall be monitored by a licensed geotechnical engineer to ensure that infiltration capacity of base and sub -base are not compromised by compaction and smoothing processes. The pavement does not Vacuum sweep the pavement. If the pavement still dewater between storms, does not dewater, consult a professional. or water is running off. Form SW401-Permeable Pavement O&M-Rev.3 Page 1 of 3 Permit Number: (to be provided by DWQ) Drainage Area / Lot Number: The permeable pavement will be inspected once a quarter 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 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 perimeter of the Areas of bare soil and/or erosive Regrade the soil if necessary to remove permeable pavement gullies have formed. the gully, and then plant a 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 3 to 6 long. inches remove clippings). The surface of the Trash/debris is present. Remove the trash/debris. permeable pavement Weeds are growing on the Do not pull the weeds (may pull out surface of the permeable media as well). Spray them with pavement. pesticide. Sediment is present on the Vacuum sweep the pavement. surface. The structure is deteriorating or Consult an appropriate professional. damaged. Damaged areas of the pavement shall be removed and repaired. The pavement does not dewater Vacuum sweep the pavement. If the between storms. pavement still does not dewater, consult a professional. Permanently clogged pavement shall be removed and repaired. Form SW401-Permeable Pavement O&M-Rev.3 Page 2 of 3 Permit Number: (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Project name: BMP drainage area or lot number: Print name: Title: Address: Phone: Signature: Date: Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. 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 forgoing permeable pavement maintenance requirements. Witness my hand and official seal, SEAL My commission expires Form SW401-Permeable Pavement O&M-Rev.3 Page 3 of 3 Permit Number: (to be provided by DWQ) Drainage Area Number: Sand Filter Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will 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 removal efficiency of the BMP. Important maintenance procedures: — The drainage area will be carefully managed to reduce the sediment load to the sand filter. — Once a year, sand media will be skimmed. — The sand filter media will be replaced whenever it fails to function properly after vacuuming. The sand filter 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 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 I will remediate theproblem: The entire BMP Trash/debris is present. Remove the trash/debris. The adjacent pavement Sediment is present on the Sweep or vacuum the sediment as (if applicable) pavement surface. soon as possible. The perimeter of the Areas of bare soil and/or Regrade the soil if necessary to sand filter erosive gullies have formed. remove the gully, and then plant a 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 long. approximatel six inches. The flow diversion The structure is clogged. Unclog the conveyance and dispose structure of any sediment off -site. The structure is damaged. Make any necessary repairs or replace if damage is too large for repair. The pretreatment area Sediment has accumulated to Search for the source of the a depth of greater than six sediment and remedy the problem if inches. possible. Remove the sediment and dispose of it in a location where it will not cause impacts to streams or the BMP. 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 a pesticide is used, wipe it on the plants rather than spraying. Form SW401-Sand Filter O&M-Rev.3 Page 1 of 3 BMP element: Potentialproblem: How I will remediate theproblem: The filter bed and Water is ponding on the Check to see if the collector system underdrain collection surface for more than 24 is clogged and flush if necessary. If system hours after a storm. water still ponds, remove the top few inches of filter bed media and replace. If water still ponds, then consult an expert. The outflow spillway Shrubs or trees have started Remove shrubs and trees and pipe to grow on the embankment. immediately. The outflow pipe is clogged. Provide additional erosion protection such as reinforced turf matting or riprap if needed to prevent future erosion problems. The outflow pipe is damaged. Repair or replace the pipe. The receiving water Erosion or other signs of Contact the NC Division of Water damage have occurred at the Quality 401 Oversight Unit at 919- outlet. 733-1786. Form SW401-Sand Filter O&M-Rev.3 Page 2 of 3 Permit Number: (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Project name: BMP drainage area number: Print name: Title: Address: Phone: Signature: Date: Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. 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 forgoing sand filter maintenance requirements. Witness my hand and official seal, SEAL My commission expires Form SW401-Sand Filter O&M-Rev.3 Page 3 of Permit Number: (to be provided by DWQ) Drainage Area Number: Stormwater Wetland Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will 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 removal efficiency of the BMP. Important maintenance procedures: — Immediately after the stormwater wetland is established, the wetland plants will be watered twice weekly if needed until the plants become established (commonly six weeks). — No portion of the stormwater wetland will be fertilized after the first initial fertilization that is required to establish the wetland plants. — Stable groundcover will be maintained in the drainage area to reduce the sediment load to the wet detention basin. — Once a year, a dam safety expert will inspect the embankment. After the wet detention pond is established, I will inspect it once a month 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 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 I will remediate theproblem: 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 necessary to wetland erosive gullies have formed. remove the gully, and then plant a 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 long. approximately six inches. The inlet device: pipe or The pipe is clogged (if Unclog the pipe. Dispose of the swale applicable). sediment off -site. The pipe is cracked or Replace the pipe. otherwise damaged (if applicable). Erosion is occurring in the Regrade the swale if necessary to swale (if applicable). smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid future problems with erosion. Form SW401-Wetland O&M-Rev.3 Page 1 of 4 BMP element: Potentialproblem: How I will remediate theproblem: The forebay Sediment has accumulated in Search for the source of the the forebay to a depth that sediment and remedy the problem if inhibits the forebay from possible. Remove the sediment and functioning well. dispose of it in a location where it will not cause impacts to streams or the BMP. 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 a pesticide is used, wipe it on the plants rather than spraying. The deep pool, shallow Algal growth covers over Consult a professional to remove water and shallow land 50% of the deep pool and and control the algal growth. areas shallow water areas. Cattails, phragmites or other Remove the plants by wiping them invasive plants cover 50% of with pesticide (do not spray) - the deep pool and shallow consult a professional. water areas. Shallow land remains flooded Unclog the outlet device more than 5 days after a immediately. storm event. Plants are dead, diseased or Determine the source of the dying. problem: soils, hydrology, disease, etc. Remedy the problem and replace plants. Provide a one-time fertilizer application to establish the ground cover if a soil test indicates it is necessary. Best professional practices Prune according to best professional show that pruning is needed practices. to maintain optimal plant health. Sediment has accumulated Search for the source of the and reduced the depth to 75% sediment and remedy the problem if of the original design depth possible. Remove the sediment and of the deep pools. dispose of it in a location where it will not cause impacts to streams or the BMP. Form SW401-Wetland O&M-Rev.3 Page 2 of 4 BMP element: Potentialproblem: How I will remediate theproblem: The embankment A tree has started to grow on Consult a dam safety specialist to the embankment. remove the tree. An annual inspection by an Make all needed repairs. appropriate professional shows that the embankment needs repair. Evidence of muskrat or Use traps to remove muskrats and beaver activity is present. consult a professional to remove beavers. The micropool Sediment has accumulated Search for the source of the and reduced the depth to 75% sediment and remedy the problem if of the original design depth. possible. Remove the sediment and dispose of it in a location where it will not cause impacts to streams or the BMP. Plants are growing in the Remove the plants, preferably by micropool. hand. If a pesticide is used, wipe it on the plants rather than spraying. The outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment off -site. The outlet device is damaged Repair or replace the outlet device. The receiving water Erosion or other signs of Contact the NC Division of Water damage have occurred at the Quality 401 Oversight Unit at 919- outlet. 733-1786. Form SW401-Wetland O&M-Rev.3 Page 3 of 4 Permit Number: (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Project name: BMP drainage area number: Print name: Title: Address: Phone: Signature: Date: Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. 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 forgoing stormwater wetland maintenance requirements. Witness my hand and official seal, SEAL My commission expires Form SW401-Wetland O&M-Rev.3 Page 4 of 4 Permit Number: (to be provided by DWQ) Drainage Area Number: Wet Detention Basin Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will 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 removal efficiency of the BMP. The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if one is provided. This system (check one): ❑ does ❑ does not incorporate a vegetated filter at the outlet. This system (check one): ❑ does ❑ does not incorporate pretreatment other than a forebay. Important 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 detention pond should be fertilized after the first initial fertilization that is required to establish the plants on the vegetated shelf. — Stable groundcover should be maintained in the drainage area to reduce the sediment load to the wet detention basin. — If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain should be minimized to the maximum extent practical. — Once a year, a dam safety expert should inspect the embankment. After the wet detention pond is established, it should be inspected once a month 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 should be kept in a known set location and must be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. BMP element: Potentialproblem: How I will remediate theproblem: The entire BMP 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 detention basin erosive gullies have formed. remove the gully, and then plant a 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 long. approximately six inches. Form SW401-Wet Detention Basin O&M-Rev.3 Page 1 of 4 Permit Number: (to be provided by DWQ) Drainage Area Number: BMP element: Potentialproblem: How I will remediate theproblem: The inlet device: pipe or The pipe is clogged. Unclog the pipe. Dispose of the swale sediment off -site. The pipe is cracked or Replace the pipe. otherwise damaged. Erosion is occurring in the Regrade the swale if necessary to swale. smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid future problems with erosion. The forebay Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design depth for possible. Remove the sediment and sediment storage. dispose of it in a location where it will not cause impacts to streams or the BMP. 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. The vegetated shelf Best professional practices Prune according to best professional show that pruning is needed practices to maintain optimal plant health. Plants are dead, diseased or Determine the source of the dying. problem: soils, hydrology, disease, etc. Remedy the problem and replace plants. Provide a one-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. The main treatment area Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design sediment possible. Remove the sediment and storage depth. dispose of it in a location where it will not cause impacts to streams or the BMP. Algal growth covers over Consult a professional to remove 50% of the area. and control the algal growth. Cattails, phragmites or other Remove the plants by wiping them invasive plants cover 50% of with pesticide (do not spray). the basin surface. Form SW401-Wet Detention Basin O&M-Rev.3 Page 2 of 4 Permit Number: (to be provided by DWQ) Drainage Area Number: BMP element: Potentialproblem: How I will remediate theproblem: The embankment Shrubs have started to grow Remove shrubs immediately. on the embankment. Evidence of muskrat or Use traps to remove muskrats and beaver activity is present. consult a professional to remove beavers. A tree has started to grow on Consult a dam safety specialist to the embankment. remove the tree. An annual inspection by an Make all needed repairs. appropriate professional shows that the embankment needs repair. The outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment off -site. The outlet device is damaged Repair or replace the outlet device. The receiving water Erosion or other signs of Contact the local NC Division of damage have occurred at the Water Quality Regional Office, or outlet. the 401 Oversight Unit at 919-733- 1786. 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. When the permanent pool depth reads sediment shall be removed. When the permanent pool depth reads shall be removed. Sediment Removal feet in the main pond, the feet in the forebay, the sediment BASIN DIAGRAM ill in the blanks) ------ --- - Volume Bottom Elevati0 -ft Min. Sediment Storage FOREBAY Permanent Pool Elevation Pool Sediment Removal Elevation Volume Bottom Elevation MAIN POND 1-ft Storage Form SW401-Wet Detention Basin O&M-Rev.3 Page 3 of 4 Permit Number: (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Project name: BMP drainage area number: Print name: Title: Address: Phone: Signature: Date: Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. 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 forgoing wet detention basin maintenance requirements. Witness my hand and official seal, SEAL My commission expires Form SW401-Wet Detention Basin O&M-Rev.3 Page 4 Of 4