New Search
03/07/95 09:45 V503 224 7820 WOODWARD -CLYDE <br /> management (Chapter 9). This manual is recommended for staff reviewing plans for <br /> development along waterways. <br /> C u ruction Site Controls - - - <br /> There are a number of references available with guidance regarding practices to <br /> reduce erosion and other pollutant discharges from construction sites. The two most <br /> extensive appear to be the Stormwater Management Manual for the Puget Sound <br /> Basin - Chapter 11 -2 (1992) and the California Storm Water Best Management Practice <br /> Handbook for Construction Activity (March 1993). We recommend that the City <br /> consider including guidance for construction site controls in the interim guidance <br /> notebook as well. <br /> Site Planning and Source Controls <br /> It is recommended that the City consider including a section in the interim guidance <br /> notebook on site planning techniques and use of structural and non - structural source <br /> controls to reduce potential for stormwater pollution. It is important for the City staff <br /> to have a good working knowledge of these concepts, because there may be times <br /> when the City staff can work with the permit applicant early in the process to <br /> configure /design the site in a way that reduces the amount of runoff discharged or <br /> maintains the quality of the runoff. Here are some examples: <br /> • Incorporate stormwater quality facilities into the landscaping requirements by <br /> designing parking medians as flow - through filters or depressed swales, rather <br /> than planted mounds. <br /> • Design the building(s) so that runoff from roof downspouts is routed to grassed <br /> swales for pre - treatment prior to discharge to the storm drain system or a <br /> drywell. <br /> • Grade the site so that no minimal runoff enters loading/unloading areas, such as <br /> loading docks. In loading areas, consider installing catchbasins with filter <br /> inserts to trap spilled materials. <br /> • Design new residential subdivisions with minimal impervious (e.g., paved) <br /> areas. <br /> As an added benefit, these innovative water quality -based site designs can reduce the <br /> amount of conventional pipe, catchbasins, and curb and gutter needed for the project, <br /> thus potentially making the project more cost- effective. <br /> S \945042na \task0200 \onsite controls \techmem.ck 15 <br />