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J t <br /> Table 3— pH-Modifying Sources <br /> None <br /> Bulk cement <br /> Cement kiln dust <br /> Fly ash <br /> Other cementitious materials <br /> New concrete washing or curing waters <br /> Waste streams generated from concrete grinding and sawing <br /> Exposed aggregate processes <br /> Dewatering concrete vaults <br /> Concrete pumping and mixer washout waters <br /> Recycled concrete <br /> Other(i.e., calcium lignosulfate) <br /> List and describe BMPs: Concrete Handling (BMP C151); Concrete Washout Area (BMP <br /> C154); High pH Neutralization Using CO2 (BMP C252); pH Control for High pH Water (BMP <br /> C253) <br /> All concrete washout waters shall be vacuumed while the work is actively occurring to prevent <br /> migration off-site, and shall not remain on existing asphalt or concrete surfaces. The washout <br /> waters shall be disposed of in a manner that does not violate surface water or groundwater <br /> quality standards. <br /> Installation Schedules: BMPs relating to pH-modifying sources shall be implemented as <br /> necessary. <br /> Inspection and Maintenance plan: BMPs relating to pH-modifying sources shall be inspected <br /> and maintained as necessary. <br /> Responsible Staff: TBD—Construction Erosion Control Lead <br /> CESCL shall adjust pH of stormwater if monitoring determines that discharge is outside the <br /> range of 6.5 to 8.5 su. <br /> CESCL shall obtain written approval from the City of Redmond and from Ecology before using <br /> chemical treatment with the exception of CO2 or dry ice to modify pH. <br /> Concrete trucks must not be washed out onto the ground, or into storm drains, open ditches, <br /> streets, or streams. Excess concrete must not be dumped on-site, except in designated <br /> concrete washout areas with appropriate BMPs installed. <br /> Page 117 <br />