13 2026 02 12 Crestmont CC Stormwater O and M Manual

rated to meet heavy-duty H-20 traffic loading requirements. Precast storm manhole structures and inlet box sizes are to be sized to accommodate the largest proposed pipe connections, and polypropylene steps shall be provided for maintenance access. Precast concrete headwalls are proposed at the outfall pipe to Small-Scale Bioretention Basin 1 (SSBB-1) and at an outfall pipe to Small-Scale Bioretention Basin 2 (SSBB-2). Precast concrete outlet control structures are proposed at the small-scale bioretention basins and the porous asphalt pavement system. 5.0 INSPECTION AND MAINTENANCE PROCEDURES The owner is responsible for maintenance identified in the maintenance manual and shall maintain a detailed log of all preventative and corrective maintenance for the structural stormwater system measures incorporated into the design of the development, including a record of all inspections and copies of all maintenance-related work orders. The owner is to evaluate the effectiveness of the maintenance plan at least once per year and adjust the plan as needed. Maintenance and inspection access to all proposed stormwater BMPs shall be maintained at all times. All components of the stormwater management measures must be readily accessible; trees, shrubs, and ornamental grasses must be pruned or trimmed as necessary to maintain access, and areas adjacent to these BMPs shall be made clear during scheduled maintenance activities to allow for ease of access for maintenance vehicles. 5.1 Preventative Maintenance Measures The frequency and type of preventative maintenance prescribed is adopted from the New Jersey Best Management Practices Manual. 5.1.1 Conveyance Networks The conveyance systems, including inlets, manholes, and pipes are expected to receive and/or accumulate debris and sediment. These systems shall be inspected for clogging and sediment accumulation at least bi-annually, and shall be inspected for trash and debris removal at least quarterly, and may require cleaning to prevent the loss of discharge capacity storage volume. Sediment removal should take place when all runoff has drained from the pipe networks and the systems are reasonably dry. Disposal of debris, trash, sediment, and other waste material should be done at suitable disposal/recycling sites and in compliance with all applicable local, state, and federal waste regulations.

s, trash, sediment, and other waste material should be done at suitable disposal/recycling sites and in compliance with all applicable local, state, and federal waste regulations. 5

All structural components must be inspected for cracking, subsidence, breaching, wearing and deterioration at least annually. The conditions of surrounding and above lying materials shall be inspected for evidence of potential failures or deterioration. Two people may be needed to perform routine maintenance of the conveyance systems. The routine equipment expected to be utilized for the maintenance tasks may include a jet vacuum vehicle, shovels, lighting equipment and a wheelbarrow or truck for the hauling off of debris. All inspections and maintenance operations shall be documented and logged. All documentations and logs shall be retained for future review. 5.1.2 Small-Scale Bioretention Basins The small-scale bioretention basins shall be inspected for sediment accumulation at least quarterly, and shall be inspected for trash and debris removal at least quarterly. The bottom elevation and design storage volume of each basin must be maintained in order to maintain adequate capacity; sediment and debris build-up shall be removed upon inspection. The basins and associated riprap aprons should be inspected for signs of erosion at least quarterly, and after each major rainfall event in excess of 2 inches. Structural components associated with the outlet control structure, including any trash racks, should be inspected at least annually. The underdrain collection piping shall be inspected at least annually for any sediment or debris build-up, and shall be jet-vacuum cleaned if necessary. Bioretention basins planted with ornamental grasses, shrubs, and trees shall be inspected at least quarterly for plant health. Dead vegetation shall be re-planted during the spring and fall growing seasons in order to maintain a minimum 90% of healthy plants at any time in order to continue promoting adequate uptake of pollutants via the root systems. Leaves and other vegetative debris shall be raked and collected on an as-needed basis in order to maintain adequate basin storage volumes. Meadow mix seeding is utilized along the bottom and embankment sides of the proposed bioretention basins. After the first growing season, and if the meadow mix seeding is well established, the meadow mix native vegetation shall be mowed only once annually in order to promote sustained growth. If the meadow mix is not fully established, the meadow mix areas shall be supplemented with

ed, the meadow mix native vegetation shall be mowed only once annually in order to promote sustained growth. If the meadow mix is not fully established, the meadow mix areas shall be supplemented with additional seeding to ensure re-establishing all meadow mix areas. The annual maintenance mowing shall be done in late winter during the month of March. 6

5.1.3 Porous Pavement Systems All components of the porous asphalt pavement system should be inspected at least twice annually unless otherwise noted. The perforated HDPE underdrain system should be inspected for clogging and jet-cleaned as necessary to remove sediment. The porous asphalt layer should be inspected for clogging at least quarterly, and after each major rain event in excess of 2 inches, for signs of clogging, sediment build-up, and weed growth. Sediment be removed and jet-cleaned as necessary, in order to maintain adequate permeability for runoff to percolate into the storage bed below. The underdrain collection piping shall be inspected at least annually for any sediment or debris build-up, and shall be jet-vacuum cleaned if necessary. 5.2 Corrective Maintenance Measures Depending on many factors, such as the performance of preventative maintenance actions, weather, or unexpected incidents, corrective maintenance requirements may not be precisely anticipated. Corrective maintenance is required on an emergency or non-routine basis to correct problems or malfunctions and to restore the components of the stormwater management system to its intended operations and safe conditions. Standing water within the proposed basins more than 72 hours after a storm event has ended is a sign that there is inadequate infiltration and/or discharge through the outlet control structure is occurring. The outlet control structure orifice openings, soil media layer, and underdrain collection piping within bioretention basins shall be inspected for sediment build-up, clogging, or debris and corrected immediately. The outlet control structure and sand layer within infiltration basins shall be inspected sediment build-up, clogging, or debris and corrected immediately. Sediment, debris, and trash which threaten the discharge capacity and storage volume of a stormwater facility should be removed immediately and properly disposed of in a timely manner, Equipment and personnel must be available to perform the removal work on short notice. Disposal of debris, trash, sediments and other waste material should be done at suitable disposal/recycling sites and in compliance with all applicable local, state and federal waste regulations. The lack of an available disposal site should not delay the removal of trash, debris, and sediment. Temporary storage shall be utilized

with all applicable local, state and federal waste regulations. The lack of an available disposal site should not delay the removal of trash, debris, and sediment. Temporary storage shall be utilized until and approved disposal site is available. Structural damage to precast structures, pipes, and trash racks must be repaired promptly. Equipment, materials and personnel must be available to perform these repairs on short notice. The immediacy of the repairs will depend upon the nature of the damage and its effects on the 7

safety and operations of the facility. The analysis of structural damage and the design and performance of structural repairs should only be undertaken by qualified personnel. All corrective maintenance operation shall be documented and logged. All documentation and logs shall be retained for future review. 6.0 ESTIMATED COST FOR MAINTENANCE PROCEDURES Storm Sewer Conveyance Systems sediment removal by jet vacuum truck (2-man crew) performed annually: $6,000 per session X 1 = $6,000.00 annual cost (if required) Bioretention basin preventative maintenance performed annually: $5,000 per session X 1 = $5,000.00 annual cost (if required) Porous Asphalt Pavement System sediment removal by jet vacuum truck (2-man crew) performed annually: $10,000 per session X 1 = $10,000.00 annual cost (if required) Trash and Debris removal by manual labor (2-man crew) performed Bi-annually $1,000.00 per session X 2 = $2,000.00 annual cost Total = $23,000.00 annual cost (if required) \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Reports\Stormwater\2026-02-12 SWM Report\O&M\Eagle Rock Stormwater O&M Manual.docx 8

DRAWINGS

OVAL RD EAGLE ROCK AVE VE ELA UR LA 2/12/2026 Langan Engineering and Environmental Services, LLC 300 Kimball Drive Parsippany, NJ 07054 T: 973.560.4900 F: 973.560.4901 www.langan.com NJ Certificate of Authorization No. 24GA27996400 © 2024 Langan Date: 3/4/2026 Time: 18:10 User: tgreen Style Table: Langan.stb Layout: CG101 Document Code: 101049802-0102-CG101-0102

OVAL RD EAGLE ROCK AVE VE E LA A UR L 2/12/2026 Langan Engineering and Environmental Services, LLC 300 Kimball Drive Parsippany, NJ 07054 T: 973.560.4900 F: 973.560.4901 www.langan.com NJ Certificate of Authorization No. 24GA27996400 © 2024 Langan Date: 3/4/2026 Time: 18:12 User: tgreen Style Table: Langan.stb Layout: CG102 Document Code: 101049802-0102-CG101-0103