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HomeMy WebLinkAboutO&M ManualStormwater Operations and Maintenance Manual Hamilton Crossing Carmel, IN Prepared for: Republic Airways 8909 Purdue Road, Suite 300 Indianapolis, IN 46268 Prepared by: Kimley-Horn and Associates, Inc. 250 East 96th Street, Suite 580 Indianapolis, Indiana 46240 Contact: Connor Strege, PE I affirm, under penalties for perjury, that I have taken reasonable care to redact each Social Security number in this document, unless required by law. – Connor Strege Prepared on: December 7, 2023 Water Quality BMPs Water Quality Best Management Practices (BMPs) are vegetative, structural, and other measures that reduce or eliminate pollutants that might otherwise be carried by surface runoff. Potential pollutant sources include litter from patrons and automobile fluids on the pavement including heavy metals, oil, grease, and alcohols. The stormwater for the site drains via sheet flow to a proposed storm network that flows through a proposed aquaswirl before it outlets into a wet detention pond. Wet detention ponds are designed with outlet control structures that slow the release of the stormwater. This allows pollutants and sediment to settle out prior to stormwater leaving the detention area. BMPs for Hamilton Crossing will include: Stormwater Retention Basin Aquaswirl Structure Stormwater Inlet Structures Stormwater Vault Topsoil, seed, and mulch on all unpaved disturbed areas See Attachment A for a BMP Location Map for this project. BMP Owner Contact Information and Billing Contact Name: Republic Airways Contact: Scott Durgin Address: 8909 Purdue Road, Suite 300 Business Phone Number: 317-484-6000 Party Responsible The BMP owner agrees to pay all the fees required by the City of Carmel, including annual inspection fees, and/or any additional fees required. Routine inspections are the responsibility of the BMP owner. Maintenance is also the responsibility of the owner. The City of Carmel must be notified of any changes in BMP ownership, major repairs, or BMP failures in writing within 30 days. The letter should be addressed to: Storm Water Program Carmel Engineering Dept. One Civic Square Carmel, IN 46032 In the event that the City of Carmel finds a BMP in need of maintenance or repair, the City of Carmel will notify the BMP owner of the necessary maintenance or repairs and give the BMP Owner a timeframe for completing the maintenance or repairs. If the maintenance or repairs are not completed within the designated timeframe, the City shall perform the repairs or maintenance and bill the BMP Owner the actual cost of the work. Submittal of annual inspection reports to the City of Carmel Engineering are due one year after construction is completed, with subsequent reports due each year within the same month of the initial report, any deficiencies found during the inspections should be addressed, and the BMP owner faces enforcement action from the City if the inspection report is not received within the month it is due, if there are deficiencies which were not included in the report, or if any deficiencies included in the report are not addressed in a timely manner. Material Handling Disposal of waste from maintenance of drainage facilities shall be conducted in accordance with federal, state, and local regulations. Removed sediment must be handled and disposed of in the garbage as solid waste. Water should be disposed of in a sanitary sewer after oils are removed using oil absorbent materials or other mechanical means. Used oil absorbents should be recycled or disposed according to the manufacturer’s instructions. Safety Work inside underground structures requires special OSHA-required confined space equipment and procedures. The most practical option to perform maintenance or repairs is to contract with a sewer- cleaning contractor Storm Structure Maintenance and Inspection Storm structures on site are identified within the construction plans set. Storm structures are set at storm sewer pipe connections. Unless you have OSHA approved training and equipment, never enter a manhole. Inspection and maintenance of all storm structures is required per the table below. Storm Structure Maintenance and Inspection Inspection All inlet castings should be inspected every 6 months and after each major rainfall event. More frequent inspections should be performed in areas where there is higher potential for trash or litter and during the fall when leaves are present on the ground. Check the frame and lid for cracks and wear, such as rocking lids or lids moved by traffic. Storm structures and the surrounding areas should be inspected annually for pollutants such as leaks from dumpsters, minor spills, and oil dumping. Take action to have the pollutant source removed. Cleaning Clean structures when there is a blockage of a water flow path or when sediment depth reaches 10% of the pipe diameter. Cleaning should be performed in a way that ensures removed sediment and water is not discharged back into the storm sewer. Materials Handling Disposal of waste from maintenance of drainage facilities shall be conducted in accordance with federal, state, and local regulations. Removed sediment must be disposed in the garbage as solid waste. Water should be disposed of in a sanitary sewer after oils are removed using oil absorbent materials or other mechanical means. Used oil absorbents should be recycled or disposed according to the manufacturer's instructions. Repairs Repair all security and access features so they are fully functional. This includes locking lids, covers, and ladder rungs. Replace broken parts or lids that rock or are moved by traffic. Stormwater Vault Maintenance and Inspection The stormwater vault detains runoff prior to discharging offsite. The stormwater vault allows sediment from incoming runoff to settle and remain within the vault while the runoff is slowly released at a designed limited rate. The bottom of the vault will be 2” of #8 stone on 6” of #8 stone wrapped in a geotextile fabric. The vault floor will help with the accumulation of sediment. Maintenance is necessary for stormwater vault to operate as designed on a long-term basis. There will be two access points to the underground detention vault in the floor of the parking garage. The pollutant and sediment removal capabilities of the vault will decrease if the vault is not properly monitored and maintained. The bottom of the vault should be regularly checked to ensure the outlet structure is clear of debris and cleaned if excessive sediment accumulation occurs. The underground detention vault should be inspected and maintained per the table below. An inspection checklist can be found in the Appendix. Underground Detention Vault Maintenance and Inspection Maintenance Activity Frequency Clean and remove debris from inlet and outlet structure Monthly and after large rainfall events As needed afterwards during dry periods. Inspect stone floor and repair eroded areas Monthly (initially). Semiannually. Inspect for damage especially at control structure, sediment accumulation Annual inspection Remove litter and debris Monthly. As needed. At a minimum, the vault should be inspected and maintained once per year and after every large rain event. An inspection checklist can be found in the Appendix B. Storm Sewer Maintenance and Inspection Storm sewer pipes convey stormwater. Pipes are built from many materials and are sometimes perforated to allow stormwater to infiltrate into the ground. Storm pipes are cleaned to remove sediment or blockages when problems are identified. Storm pipes must be clear of obstructions and breaks to prevent localized flooding. Storm sewer maintenance and inspection required per the table below. Storm Sewer Maintenance and Inspection Inspection Pipes are difficult to inspect requiring special equipment and training. Usually, if a problem occurs the owner needs to call a sewer or plumbing contractor to inspect, repair or clean pipelines. Cleaning Clean pipes when sediment depth is greater than 10% of the pipe diameter. When cleaning a pipe, minimize sediment and debris discharges from pipes to the storm sewer. Install downstream debris traps (where applicable) before cleaning and then remove material. Generally, use mechanical methods to remove root obstructions from inside storm sewer pipes. Do not put root-dissolving chemicals in storm sewer pipes. If there is a problem, remove the vegetation over the line. Materials Handling Sediment and debris from pipes should be disposed in the garbage as solid waste. Pick out any rocks first. Repairs Repair or replace pipes when a dent or break closes more than 20 percent of the pipe diameter. Repair or replace pipes damaged by deterioration. AquaswirlTM Structure An AquaSwirlTM Concentrator is a swirl concentrator that removes pollutants from stormwater. These pollutants include anything that is significantly heavier or lighter than water. Such pollutants include sediment and oil from parking lots, Styrofoam cups and food packaging, cigarette butts, and other debris. The AquaSwirlTM will also remove any heavy metals or nutrients (phosphorous and nitrates) that will bond to the sediment and organic material that the AquaSwirlTM removes. The AquaSwirlTM is a one-piece plastic, or Fiberglass Re-enforced Plastic (FRP), structure that includes a cast iron frame and cover. The cover of the AquaSwirlTM has the company logo on it to make it easy to find for maintenance. The opening has a 30” diameter to provide easy access for maintenance from grade level. There should never be a need for someone to enter the AquaSwirlTM. It is designed so that inspection and maintenance can be easily conducted from grade level. Because AquaSwirlTM’s collect pollutants, they need to be inspected and cleaned periodically.The owner of the property where an AquaSwirlTM is installed is responsible for maintaining the system and the associated cost. Wet and Dry Detention Basin Maintenance and Inspection The wet and dry detention basins detain runoff prior to discharging offsite. The wet detention pond allows sediment from incoming runoff to settle and remain within the pond while the runoff is slowly released at a designed limited rate. Maintenance is necessary for both the wet and dry detention pond to operate as designed on a long-term basis. The pollutant and sediment removal capabilities of the ponds will decrease if the ponds are not properly monitored and maintained. The edges of the wet pond should be regularly mowed, checked to ensure the outlet structure is clear of debris and cleaned if excessive sediment accumulation occurs. It is important to ensure that the edges of the wet pond is heavily vegetated with grass to prevent erosion. The pond should be inspected and maintained per the table below. An inspection checklist can be found in the Appendix. Wet and Dry Basin Maintenance and Inspection Maintenance Activity Frequency Clean and remove debris from inlet and Monthly and after large rainfall events outlet structure and mow side slopes As needed afterwards during dry periods. Treat invasive vegetation, diseased trees and shrubs As needed. All should be inspected twice per year for evaluation. Inspect rip rap area and repair eroded areas Monthly (initially). Semiannualy. Planting soils, wetland plant management and harvesting Annually Inspect for damage especially at control structure, sediment accumulation Annual inspection Remove litter and debris Monthly. As needed. Monitor sediment accumulations and remove sediment when the pool volume has become reduced significantly, or the pond becomes eutrophic 10 to 20 years or after 25% of the permanent pool volume has been lost At a minimum, the basin should be inspected and maintained once per year and after every large rain event. An inspection checklist can be found in the Appendix B. Turf Vegetative Coverage All non-paved areas that are not landscaped shall be vegetated to prevent erosion and sediment buildup in storm sewer facilities onsite or downstream of the project site. Seed shall be reapplied as required to establish healthy, dense coverage. Riprap at Pipe Outlets Stormwater drainage will flow out of the storm sewer pipes and across stone riprap pads. The riprap areas will slow the water velocity to avoid soil erosion. Riprap shall be added or repaired if erosion or scour is observed. The following Operation & Maintenance (O & M) procedures are the specific responsibilities for the owner. Refer to the Tabular Maintenance Schedule included in Attachment B of this report for maintenance requirements. Right of Entry This Operation and Maintenance Manual is submitted to the City with the intent to ensure the longevity and adequate functioning of the BMPs owned by Republic Airways. By submitting this Operation and Maintenance Manual to the City of Carmel with plans to construct said BMPs, the BMP owner noted above grants personnel from the City of Carmel the right to enter the development to inspect and maintain the BMP. The BMP owner noted above agrees to follow and abide by the inspection schedule and maintenance activities listed in this manual. The BMP owner noted above is responsible for any additional maintenance and/or repair activities to maintain the function and longevity of the BMPs. Owner Acknowledgement Signature Date Printed STATE OF _______________) ) SS: COUNTY OF ____________ ) BEFORE ME THE UNDERSIGNED NOTARY PUBLIC, IN AND FOR THE SAID COUNTY AND STATE, PERSONALLY APPEARED _____________________ AND ACKNOWLEDGED THE EXECUTION OF THE FORGOING INSTRUMENT AS THEIR VOLUNTARY ACT AND DEED. WITNESS MY HAND AND NOTARY SEAL THIS _____ DAY OF ____________________, 2021. SIGNATURE: _____________________PRINTED NAME: ___________________ MY COMMISSION EXPIRES: ______________COUNTY OF RESIDENCE: _______________ Owner Acknowledgement Agreement (“Agreement”) For good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned owner (“Owner”) hereby submits this Operation and Maintenance Manual (“Manual”) to the City of Carmel, Indiana (“City”) as a written acknowledgement of Owner’s warranty and agreement to institute, maintain, and follow the water quality Best Management Practices (“BMPs”) listed below, and to follow and abide by the inspection schedule and maintenance activities listed in this Manual. The Owner also hereby agrees to provide, at Owner’s cost, all additional maintenance, repair, and/or replacement services reasonably necessary to maintain the function and longevity of the BMPs from and including the date this Agreement is executed by Owner to and including the date on which a new Agreement is filed with the City by another party who assumes all the obligations and responsibilities of Owner as set forth herein. BMPs: Stormwater Retention Basin, Aquaswirl Structure, Stormwater Inlet Structures, and Stormwater Vault. Topsoil, seed, and mulch on all unpaved disturbed areas. Owner Acknowledgement Signature Date Printed STATE OF _______________ ) ) SS: COUNTY OF ____________ ) BEFORE ME THE UNDERSIGNED NOTARY PUBLIC, IN AND FOR THE SAID COUNTY AND STATE, PERSONALLY APPEARED _____________________ AND ACKNOWLEDGED THE EXECUTION OF THE FORGOING INSTRUMENT AS THEIR VOLUNTARY ACT AND DEED. WITNESS MY HAND AND NOTARY SEAL THIS _____ DAY OF ____________________, 2021. SIGNATURE: _____________________PRINTED NAME: ___________________ MY COMMISSION EXPIRES: ______________COUNTY OF RESIDENCE: _______________ List of Attachments Attachment A: BMP Location Map Exhibit Attachment B:Construction Site Inspection and Maintenance Logs Attachment A: BMP Location Map 24.07'8.75'10.00'5.00'5.00'10.00'10.00'5.00'10.00'21.35'21.80'6.26'7.43'3.64'10.00'5.00'5.00'10.00'10.00'5.00'10.00'21.35'21.80'6.26'7.43'3.64'U.S. 31U.S. 31WEST CARMEL DRIVEPENNSYLVANIA AVEPENNSYLVANIA AVE5.00'10.00'5.00'5.00'10.00'5.00'EXISTING HOTEL±13,812 SFFFE: 862.39PROPOSED HOTELEXPANSION±15,150 SFFFE: 862.39PROPOSED BUILDING 1± 51,827 SFFFE = 862.40FUTUREBUILDINGFUTUREBUILDINGFUTUREBUILDINGGARAGEBUILDING±35,050 SFFFE: 862.0024.07'8.75'10.00'5.00'5.00'10.00'10.00'5.00'10.00'21.35'21.80'6.26'7.43'3.64'10.00'5.00'5.00'10.00'10.00'5.00'10.00'21.35'21.80'6.26'7.43'3.64'PROPOSEDHEADQUARTERSFFE = 862.40December 07, 2023 0'80'40'NORTHHAMILTON CROSSING O&M EXHIBIT CARMEL, IN December 07, 2023 HAMILTON CROSSING O&M EXHIBIT CARMEL, IN Attachment B: Inspection and Maintenance Checklist Plan View SCALE 1:40 Elevation View SCALE 1:40 Projected View SCALE 1:70 2733 Kanasita Drive, Suite 111, Chattanooga, TN 37343 Phone (888) 344-9044 Fax (423) 826-2112 www.aquashieldinc.com Structure #: Drawn By: Scale: Date: OFlores Rvwed Rvw. Date U.S. Patent No. 6524473 and other Patent Pending Aqua-SwirlŠ XCelerator Standard Detail As Shown 2/25/2021 el. Varies Inlet/Outlet Invert el. Varies el. Varies Grade (Rim) el. Varies XC-4 CCW XC-4 STD Aqua-SwirlŠ Polymer Coated Steel (PCS) Stormwater Treatment System 12 in [305 mm] Manhole Frame & Cover Detail For Non-Traffic Areas Only NTS 48 in [1219 mm] Min. Gravel Backfill Concrete Wrap Compressible Expansion Joint Material to a minimum 1/2-inch [13 mm] thickness around top of riser to allow transfer of inadvertent loading from manhole cover to concrete slab. Riser Soil Cover Frame 1/2 in [13 mm] 1/2 in [13 mm] Place small amount of concrete [3,000 psi [20 MPa] (min)] to support and level manhole frame. DO NOT allow manhole frame to rest upon riser. Backfill (90% Proctor Density) 8 in [203 mm] 4 1/2 in [114 mm] Unless other traffic barriers are present, bollards shall be placed around access riser(s) in non-traffic areas to prevent inadvertent loading by maintenance vehicles. Manhole Frame & Cover Detail For Traffic Loading Areas NTS Cover Frame 48 in [1219 mm] Min. Backfill (90% Proctor Density) 3,000 psi [20 MPa] (min) Concrete #4 [13 mm] Rebar @ 6 in [152 mm] Each Way 30 in [762 mm] Riser 1/2 in [13 mm] 4 1/2 in [114 mm] 14 in [356 mm] 1/2 in [13 mm] Thick Expansion Joint Material If traffic loading (HS-25) is required or anticipated, a 4-foot [1.22 m] diameter, 14-inch [356 mm] thick reinforced concrete pad must be placed over the Stormwater Treatment System Riser to support and level the manhole frame, as shown. The top of riser pipe must be wrapped with compressible expansion joint material to a minimum 1/2-inch [13 mm] thickness to allow transfer of wheel loads from manhole cover to concrete slab. Manhole cover shall bear on concrete slab and not on riser pipe. The concrete slab shall have a minimum strength of 3,000 psi [20 MPa] and be reinforced with #4 [13 mm] reinforcing steel as shown. Minimum cover over reinforcing steel shall be 1-inch [25 mm]. Top of manhole cover and concrete slab shall be level with finish grade. Please see accompanied Aqua-SwirlŠ specification notes. See Site Plan for actual System orientation. Approximate dry (pick) weight: 2000 lbs [900 kg]. Backfill shall extend at least 18 inches [457 mm] outward from Swirl Concentrator and for the full height of the Swirl Concentrator (including riser) extending laterally to undisturbed soils. (See MH Detail Below) 1 1 As an alternative, 42 in [1067 mm] diameter, HS-20/25 rated precast concrete rings may be substituted. 14 in [356 mm] thickness must be maintained. XC-4 inlet/outlet pipe size ranges up to 27 in [686 mm]. XC-4 chamber height may vary up to 99 in [2515 mm], depending on inlet/outlet pipe size. Orientation may vary from a minimum of 90ƒ to a maximum of 180ƒ. Clockwise or counterclockwise orientation as needed. 2 3 3 2 66 in [1676 mm] 66 in [1676 mm] P27 in [P686 mm] 2 Octagonal Base Plate P54 in [P1375 mm] 99 in [2515 mm] Varies Varies 5 [127 mm] MH Frame P30 in [P762 mm] Band Coupler by Manufacturer. (as needed) Riser Manhole Frame and Cover by Manufacturer. (See Details) Rim elevations to match finish grade. 57 in [1448 mm] Pipe coupling by Contractor. 12 in [305 mm] long Stub-out by Manufacturer. Pipe coupling by Contractor. 12 in [305 mm] long Stub-out by Manufacturer. 4 4 P54 in [P1372 mm] Optional inlet orientations available (See note 4) P27 in [P686 mm] 180ƒ Lifting Lugs Backfill Bedding Undisturbed soil 18 in [457 mm] 6 in [152 mm] Lifting Lugs Storm Sewers and Storm Structures Operation, Maintenance, and Management Inspection Checklist Project: Location: Date: Time: Inpsector: Title: Signature: Visual evidence of broken or cracked frame or casting? Clear of debris? Debris within structure? 2. Condition of Frame and Casting 1. Structural Condition Any indications of structural failure? Pipes are clear of debris? Storm Structures Maintenance Item Satisfactory / Unsatisfactory Comments Storm Sewers 1. Structural Condition & Capacity CommentsSatisfactory / UnsatisfactoryMaintenance Item Indications of deformed or sagging pipes? Surcharges onsite to indicate a blockage? Maintenance Standards derived from the Washington State Department of Ecology’s Stormwater Management Manual for Eastern Washington (September 2004). Page 5 Maintenance Standards Conveyance Systems (Pipes and Ditches) Maintenance Code Type Conditions When Maintenance Is Needed 1 Sediment Sediment or debris exceeds 20% of pipe diameter or 20% of debris barrier openings. Accumulated sediment that exceeds 20% of the design depth of the ditch. 2 Trash & Debris Trash and debris accumulated in pipe or ditch. Visual evidence of dumping 3 Vegetation Vegetation reduces movement of water through pipes. Excessive vegetation that reduces free movement of water through ditches. 4 Water Quality Any evidence of oil, gasoline, contaminants or other pollutants. Water flowing in pipes or ditch during dry weather – report as potential illicit discharge concern. 5 Water Flow Impeded water flow due to vegetation or sediment (use appropriate code from above). Standing water in the pipe or swale between storm events. 6 Erosion Erosion damage over 2 inches deep where cause is still present or there is potential for continued erosion. Native soil is visible beneath the rock lining of a conveyance ditch. 7 Cover/Frame/ Grate N/A 8 Structure Debris barrier/trash rack is missing or not attached to pipe. Debris barrier/trash rack bars are bent by more than 3 inches. Debris barrier/trash rack bars are loose or rust is causing 50% deterioration to any part of the barrier. 9 Damaged Pipes Protective coating is damaged or rust is causing more than 50% deterioration to any part of pipe. Any dent that decreases the flow area by more than 20% or puncture that impacts performance. 10 Mosquito Vector Breeding Suitable habitat exists for mosquito production (e.g. standing water for more than 72 hours in areas accessible to mosquitoes.) 11 Other 12 Could Not Locate Field inspectors are unable to locate the pipe or ditch. Maintenance Standards derived from the Washington State Department of Ecology’s Stormwater Management Manual for Eastern Washington (September 2004). Page 6 Maintenance Standards Drywells Maintenance Code Type Conditions When Maintenance Is Needed 1 Sediment Sediment depth exceeds 2 feet or impedes flow from inlet pipes. 2 Trash & Debris Trash or debris exceeds 2 feet or impedes flow from inlet pipes. Trash or debris blocks more than 1/3 of any inlet or outlet pipe. Dead animals or vegetation that generate odors and cause complaints or dangerous gases (e.g., methane). 3 Vegetation Vegetation growing in inlet/outlet pipe joints that is more than six inches tall. Root systems entering drywell. 4 Water Quality Any evidence of oil, gasoline, contaminants or other pollutants. Water flowing into drywell during dry weather – report as potential illicit discharge concern. 5 Water Flow Facility does not drain within 72 hours. Impeded water flow due to vegetation or sediment (use appropriate code from above). 6 Erosion N/A 7 Cover/Frame/ Grate Cover is missing or only partially in place. One maintenance person cannot remove lid after applying normal lifting pressure. Frame separated by more than ¾ inch from top slab. Frame not securely attached. Locking mechanism cannot be opened by one maintenance person with proper tools. Bolts into frame have less than 1/2 inch of thread. 8 Structure Top slab with holes larger than 2 square inches or cracks wider than 1/4 inch. Grout at inlet/outlet pipes has separated or cracked wider than ½ inch and longer than one foot. Settlement has created a safety, function, or design problem. Field inspector judges that structure is unsound. 9 Damaged Pipes Inlet piping damaged or broken and in need of repair. 10 Mosquito Vector Breeding Suitable habitat exists for mosquito production (e.g. standing water for more than 72 hours in areas accessible to mosquitoes.) 11 Other 12 Could Not Locate Field inspectors are unable to locate the drywell. Wet and Dry Basin Operation, Maintenance, and Management Inspection Checklist Project: ___________________________________________________________________________ Location: ___________________________________________________________________________ Date: _________________________________________ Time: _____________________________ Inspector: _________________________________________ Title: ____________________________ Signature: _____________________________________ □ Annual Inspection □ Rain Event (>3”) Satisfactory/ Maintenance Item Unsatisfactory Comments 1. Embankment Healthy vegetation with at least 85% ground cover. No signs of erosion on embankment. No animal burrows. Embankment is free of cracking, bulging, or sliding. Embankment is free of woody vegetation. Embankment is free of leaks or seeps. 2. Wet and Dry Basin Areas Healthy vegetation with at least 85% ground cover. No undesirable woody vegetation Low flow channels clear of obstructions No evidence of sediment and/or trash accumulation Sediment Accumulation <1’ (Maintenance required if greater) Length of time for standing water <48 hrs (Maintenance required if longer) Satisfactory/ Maintenance Item Unsatisfactory Comments 3. Condition of Outfall into Wet and Dry Basin No riprap failures No evidence of slope erosion or scouring Storm drain pipes are in good condition, with no evidence of non-stormwater discharges Endwalls/Headwalls are in good condition Stormwater Underground Detention Vault Operation, Maintenance, and Management Inspection Checklist Project: ___________________________________________________________________________ Location: ___________________________________________________________________________ Date: _________________________________________ Time: _____________________________ Inspector: _________________________________________ Title: ____________________________ Signature: _____________________________________ □ Annual Inspection □ Rain Event (>3”) Satisfactory/ Maintenance Item Unsatisfactory Comments 1. Structure Structure is free of cracking, bulging, or sliding. Structure is free of leaks or seeps. 2. Stormwater Vault Areas Incoming and outgoing storm sewers are free of obstructions No evidence of sediment and/or trash accumulation Sediment Accumulation <1’ (Maintenance required if greater) Length of time for standing water <48 hrs (Maintenance required if longer) 3. Condition of Outfall into Storm System No riprap failures No evidence of gravel erosion or foundation scouring Storm drainpipes are in good condition, with no evidence of non-stormwater discharges Concrete pads are in good condition