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1. Designed with accepted engineering_practices and in accordance with part d. (Permanent Stormwater Management System Design Criteria). 2. Designed so that discharges from the project during and after construction activities do not cause a violation of state water quality standards, including nuisance conditions, erosion in receiving channels or on downslope properties, or a significant adverse impact to wetlands caused by inundation or decrease of flow. 3. Treat the water quality volume on any project where the sum of the new impervious surface and the fully reconstructed impervious surface equals one or more acres. 4. For construction activity (excludinglinear near projects), water quality volume must be calculated as one(1) inch times the sum of the new and the fully reconstructed impervious surface. 5. For linear projects, water quality volume must be calculated as the larger of one (1) inch times the new impervious surface or one-half(0.5) inch times the sum of the new and the fully reconstructed impervious surface. Where the entire water guality_volume cannot be treated within the existing right-of-way, a reasonable attempt to obtain additional right-of-way, easement, or other permission to treat the stormwater during the project planning_process must be made. Volume reduction practices must be considered first, as described in Section 3.b.vi. Volume reduction practices are not required if the practices cannot be provided cost effectively. If additional right-of-way, easements, or other permission cannot be obtained, the owner/operator of construction activity must maximize the treatment of the water quality volume prior to discharge from Arden Hill's MS4. 6. Volume reduction practices e.g., infiltration or other) to retain the water quality volume on-site must be considered first when designing the permanent stormwater treatment system. Wet sedimentation basins and filtration systems are not considered volume reduction practices. If infiltration is prohibited, as described in Part d.i.14. (Infiltration System), other volume reduction practices, a wet sedimentation basin, or a filtration basin may be considered. C. Post Long-term Maintenance 1. The Permitee must enter into a long-term maintenance agreement with the City of Arden Hills that documents all responsibilities for long-term operation and maintenance of stormwater treatment practices that are not owned or operated by the City of Arden Hills. At a minimum, the long-term maintenance agreement must include provisions that: (i) Allow the City of Arden Hills to conduct inspections of structural stormwater BMPs not owned or operated by the City of Arden Hills,perform necessary maintenance, and assess costs for those structural stormwater BMPs when the City of Arden Hills determines the owner of that structural stormwater BMP has not ensured proper function; (ii) Are designed to preserve the City of Arden Hills right to ensure maintenance responsibility, for structural stormwater BMPs not owned or operated by the Page 2 of 7