Stormwater Management Operation and Maintenance Manual Feb 2026 resubmissionrcd 2 26

below are the Preventative and Corrective Maintenance Procedures to be performed on a routine basis: 1. Preventive Maintenance Procedures: The purpose of Preventative Maintenance is to maximize the effectiveness of the stormwater management aspects of the basin so that it remains operational and safe as often as practicable and to minimize the need for emergency or corrective maintenance. These procedures are as follows: a) Removal and Disposal of Trash/Debris and Sediment: All stormwater management components expected to receive and/or trap debris and sediment must be inspected for clogging and excessive debris and sediment accumulation at least four times annually as well as after every storm exceeding one inch of rainfall. Such components may include the basin, stormwater conveyance network (piping & inlet), and outlet control structure. These stormwater management components shall be visually inspected for the accumulation of excessive sediment as well as damage in the form of cracking, erosion, and rutting. Sediment build-up within the stormwater conveyance network shall be removed with the use of flushing. Sediment-laden water is to be captured with the use of a pipe plug, or approved equal, prior to the basin and simultaneously pumped out with the use of a pump with a sediment bag. Sediment should be disposed of in accordance with all applicable local, state, and federal regulations. Removal of trash and debris will prevent possible damage to trash racks and outlet structure openings and eliminate potential mosquito breeding habitats. Debris and trash must be properly hauled off the site and transferred to an approved disposal site. The basin should also be evaluated for excessive deposition of sediment. Accumulated sediment should be removed utilizing light-weight equipment to avoid soil compaction before it threatens the storage volume of the basin. Before de-sedimentation activities are performed, consideration should be given to evacuating all standing water from the basin. This may be accomplished by clearing any blocked openings of the outlet structure or by mechanical means (pumping). Disposal of discharged water and sediment must comply with all local, county,

be accomplished by clearing any blocked openings of the outlet structure or by mechanical means (pumping). Disposal of discharged water and sediment must comply with all local, county, state, and federal regulations. Only suitable disposal sites should be utilized. If stable soil conditions exist on site, sediment deposition should not be an excessive maintenance issue. Should a recurrent stabilization situation develop, the inspector should identify the upstream sources of sediment and recommend required stabilization measures. Access has been provided for inspection and maintenance of the basin and its components. Mavis Tire Supply, LLC February 2026 DEC# 1956-24-04187 3