ORD 1971 - Laserfiche WebLink

stormwater Design Requirements 53. The project shall comply with the Alameda Countywide NPDES Permit #CA50029831, a copy of which is available at the City offices. The following requirements shall be incorporated into the project: a) The project developer shall submit a final grading and drainage plan prepared by a licensed civil engineer depicting all final grades and on-site drainage control measures including bio-swales. Irrigated bio-swales shall be redesigned as needed to the satisfaction of the City Engineer to optimize the amount of the storm water running off the paved surface that enters the bio-swale at its most upstream end. This plan shall be subject to the review and approval of the City Engineer prior to the issuance of any building permits. b) In addition to natural controls the project developer may be required to install a structural control, such as an oil/water separator, sand filter, or approved equal (in the parking lot) (on the site) to intercept and pretreat storm water prior to reaching the storm drain. The design, locations, and a schedule for maintaining the separator shall be submitted to the City Engineer/Chief Building Official for review and approval prior to issuance of building permits. The structural control shall be cleaned at least twice a year: once immediately prior to October 15 and once in January. The project developer shall enter into a maintenance agreement for the oil/water separator. c) The project developer shall submit sizing designs criteria to treat stormwater runoff at the time of plan submittal. d) Landscaping shall be designed to minimize irrigation and runoff, promote surface infiltration where appropriate, and minimize the use of fertilizers and pesticides that can contribute to stormwater pollution. 1) Structures shall be designed to discourage the occurrence and entry of pests into buildings, thus minimizing the need for pesticides. 2) Where feasible, landscaping shall be designed and operated to treat stormwater runoff. In areas that provide detention of water, plants that are tolerant of saturated soil conditions and prolonged exposure to water shall be specified. Soil shall be amended as required. 3) Plant materials selected shall be appropriate to site specific characteristics such as soil type, topography, climate, amount and timing of sunlight, prevailing winds, rainfall, air movement, patterns of land use, ecological consistency and plant interactions to ensure successful establishment. 9