(a) General: The storm water system, including storm water management practices for storage, treatment and control, and conveyance facilities, shall be designed to prevent structure flooding; to maintain predevelopment runoff patterns, flows, and volumes; by ensuring compliance with all performance standards set forth in the most recent edition of the Tnembull County Drainage and Erosion and Sedimentation Control Manual.
(b) Storm Water Conveyance Design Criteria: All storm water conveyance practices shall be designed to the storm drainage systems requirements as set forth in the most recent edition of the Trumbull County Drainage and Erosion and Sedimentation Control Manual, to convey storm water to allow for the maximum removal of pollutants and reduction in flow velocities.
(c) Storm Water Quality Control: All storm water quality control practices shall be designed utilizing the post-construction storm water quality control method and recommended post-construction best management practices as set forth in the most recent edition of the Trumbull County Drainage and Erosion and Sedimentation Control Manual and shall meet the following general performance standard:
(1) Criteria for the Acceptance of Alternative post-construction BMPs: The applicant may request approval from the City of Hubbard Engineer for the use of alternative structural post-construction BMPs if the applicant shows to the satisfaction of the City of Hubbard Engineer that these BMPs are equivalent in pollutant removal and runoff flow/volume reduction effectiveness to those listed in the most recent edition of the Trumbull County Drainage and Erosion and Sedimentation Control Manual. If the site is greater than five (5) acres, or less than five (5) acres but part of a larger common plan of development or sale which will disturb five (5) or more acres, prior approval from the Ohio EPA is necessary. To demonstrate the equivalency, the applicant must show:
A. The alternative BMP has a minimum total suspended solid (TSS) removal efficiency of 80 percent, using the Level II Technology Acceptance Reciprocity Partnership (TARP) testing protocol.
B. The water quality volume discharge rate from the selected BMP is reduced to prevent stream bed erosion, unless there will be negligible hydrologic impact to the receiving surface water of the State. The discharge rate from the BMP will have negligible impacts if the applicant can demonstrate one of the following conditions:
1. The entire water quality volume is recharged to groundwater.
2. The development will create less than one acre of impervious surface.
3. The development project is a redevelopment project with an ultra-urban setting, such as a downtown area, or on a site where 100 percent of the project area is already impervious surface and the storm water discharge is directed into an existing storm sewer system.
The storm water drainage system of the development discharges directly into a large river of fourth order or greater or to a lake, and where the development area is less than 5 percent of the water area upstream of the development site, unless a Total Maximum Daily Load (TMDL) has identified water quality problems in the receiving surface water of the State.
(d) Storm Water Quantity Control: The Comprehensive Storm Water Management Plan shall describe how the proposed storm water management practices are designed to meet the post-construction storm water quantity control method requirement as set forth in the most recent edition of the Trumbull County Drainage and Erosion and Sedimentation Control Manual for storm water quantity control for each watershed in the development:
(e) Storm Water Management on Redevelopment Projects: Comprehensive Storm Water Management Plans shall be designed to the requirements as set forth in the most recent edition of the Trumbull County Drainage and Erosion and Sedimentation Control Manual.
(Ord. 11-10. Passed 4-19-10.)