Laserfiche WebLink
8.B. - Page 60 <br /> MM HYD 1-3: All exposed or disturbed soil surfaces would be watered at least twice daily to <br /> control dust as necessary. <br /> MM HYD 1-4: Stockpiles of soil or other materials that can be blown by the wind would be <br /> watered during the dry season to prevent wind erosion. Stockpiles of soil or <br /> other materials shall be covered during the wet season to prevent stormwater <br /> pollution runoff. <br /> MM HYD 1-5: All trucks hauling soil, sand, and other loose materials would be covered and <br /> all trucks would be required to maintain at least two feet of freeboard. <br /> MM HYD 1-6: The construction site would be swept daily to minimize wind erosion and <br /> reduce water pollution. All paved access roads,parking areas, staging areas <br /> and residential streets adjacent to the construction site would be swept daily. <br /> MM HYD 1-7: Vegetation in disturbed areas would be replanted as quickly as possible. <br /> Post-Construction <br /> Implementation of the proposed project will result in an increase in pollutant loads due to an increase <br /> of impervious surfaces on-site. The project will contribute the same types of stormwater runoff <br /> pollutants as the e�sting development. Street and parking area runoff often carries grease, oil, and <br /> trace amounts of heavy metals into natural drainages. Runoff from landscaping can carry pesticides, <br /> herbicides, and fertilizers. Although the amounts of these pollutants ultimately discharged into the <br /> waterways are unknown, over time they could be substantial. <br /> The existing and proposed square footages of pervious and impervious surfaces are shown on Table <br /> 3,below. The e�sting project site is appro�mately 31,107 sf, of which appro�mately 21 percent is <br /> comprised of impervious surfaces. The proposed project will add/replace 9,760 sf of impervious <br /> surfaces on-site. The remaining 21,347 sf will be open space comprised of pervious surfaces and <br /> landscaping. The project will result in a net increase in impervious surfaces on the site, so <br /> implementation of the proposed project will incrementally increase the amount of runoff and <br /> pollution flowing into the storm drain system. <br /> TABLE 3 <br /> Pervious and Im ervious Surfaces On-Site <br /> Existing/Pre- o Project/Post- o�a Difference o <br /> Site Surface Construction /a /a <br /> �s� Construction (sf) (sf) <br /> Im ervious <br /> Buildin Foot rint 2,090 6.7 6,723 21.6 4,633 14.9 <br /> Parkin /Drivewa s 3,652 11.7 3,037 9.8 -615 -2.0 <br /> Sidewalks/Patios/Paths 741 2.4 0 0 -741 -2.4 <br /> Subtotal 6,483 20.8 9,760 31.4 3,277 10.S <br /> Pervious <br /> Pervious Pavement and <br /> Landsca in 24,624 792 21,347 68.6 -3,277 -10.5 <br /> TOTAL 31,107 100.0 31,107 100.0 <br /> *NOTE: Due to rounding,percentages may not be exact. <br /> 1410 Valota Road Residential Project 48 Initial Study <br /> Redwood City January 2012 <br />