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<br />Chapter 2-Storm Water Pollution Prevention PI/ln <br /> <br />landscaping, reduce the amount of sediment and storm water managem ant controls, and improve <br />the aesthetics of the completed project. <br /> <br />Once the preliminary design is developed, you should prepare a narrativE! description of the nature <br />of the construction activity to include in the Storm Water Pollution P,'evl!ntion Plan. The narrative <br />should provide a brief description of the project including the purpOSEl of the project (the final <br />result); the major soil disturbing activities that will be necessary to c()mplete the project; and the <br />approximate length of time it will take to complete the project. <br /> <br />You might describe the purpose of construction (goal or project result) as one of the following; <br />residential development, commercial, industrial, institutional, office d,avelopment. highway projects, <br />roads, streets, or parking lots, recreational areas, or underground utility. <br /> <br />When you describe soil disturbing activities you might include one or more of the following; <br />clearing and grubbing, excavation and stockpiling, rough grading, final or finish grading, preparation <br />for seeding or planting, excavation of trenches, demolition, etc. <br /> <br />The description of the construction activity does not need to address indoor construction activities <br />that will not have any affect on the Quality of storm water. For examplEI, it is not necessary to <br />describe the construction of indoor wiring for a building in the narrative if the wiring will not be <br />installed until after the building is enclosed. <br /> <br />2.1.3 Prepare Site Map <br /> <br />When the site plan is complete for your construction project, the inform etion should be transferred <br />onto the pollution prevention plan site map (Note: the construction !iite plan and the Storm Water <br />Pollution Prevention Plan site map can be the same map). At this ph.ese in the Storm Water <br />Pollution Prevention Plan development, there are three things which c:an be indicated on the site <br />map: the approximate slopes after grading, the drainage pattern, ancl the areas of disturbance. <br />[Note the surface waters should already be indicated on the map (sell S.lction 2.1.1 ).] Appendix C <br />includes an example site map for a Storm Water Pollution Prevention Plan. It may be helpful to <br />refer to this while reading this section. <br /> <br />Approximate Slopes after Grading <br /> <br />It is suggested that you indicate the revised grades on the same topographic map as the existing <br />grades. You should use two separate symbols for existing contours ;end proposed contour (i.e., <br />dashed and solid lines). Topographic maps indicating existing and proposed contours for a site are <br />suggested because it is easy to determine the areas which must be disturbed for regrading. <br /> <br />If you do not prepare a topographic map of the site. then you should examine the proposed plan for <br />the site and indicate on the site map the approximate location, directllon and steepness of slopes. <br />The location and direction of the slope may be indicated by arrows (pointing from high to low) and <br />numbers indicating the degree of slope. Slope is usually expressed a" a ratio of the length it takes <br />to decrease one foot in height, e.g., 3:1 indicates that the slope take:; 3 feet in length to drop one <br />foot in height. <br /> <br />Areas of Soil Disturbance <br /> <br />After indicating the proposed grading on the site map, the next phase is to indicate the entire area <br />which will be disturbed by the construction activity. The suggested method for indicating this area <br />is to draw a "limit of disturbance" line on the site plan. You should draw the limit of disturbance <br /> <br />2-6 <br /> <br />September 1992 <br /> <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />a <br />I <br />I <br />1 <br /> <br />I <br />I <br /> <br />I <br />I <br />I <br />I <br />I <br />