7805 40TH AVE W 2022-05-12 - Laserfiche WebLink

Table 3—pH-Modifying Sources ❑ None ® Bulk cement ® Cement kiln dust ® Fly ash ] Other cementitious materials ® New concrete washing or curing waters ® Waste streams generated from concrete grinding and sawing V1 Exposed aggregate processes Dewatering concrete vaults ❑ Concrete pumping and mixer washout waters ❑ Recycled concrete ❑ Recycled concrete stockpiles ❑ Other(i.e., calcium lignosulfate) [please describe: ] Stormwater runoff will be monitored for pH starting on the first day of any activity that includes more than 40 yards of poured or recycled concrete, or after the application of"Engineered Soils" such as,Portland cement treated base,cement kiln dust,or fly ash. This does not include fertilizers. For concrete work, pH monitoring will start the first day concrete is poured and continue until 3 weeks after the last pour. For engineered soils,the pH monitoring period begins when engineered soils are first exposed to precipitation and continue until the area is fully stabilized. Stormwater samples will be collected daily from all points of discharge from the site and measured for pH using a calibrated pH meter,pH test kit,or wide range pH indicator paper. If the measured pH is 8.5 or greater,the following steps will be conducted: 1. Prevent the high pH water from entering storm drains or surface water. 2. Adjust or neutralize the high pH water if necessary using appropriate technology such as CO2 sparging(liquid or dry ice). 3. Contact Ecology if chemical treatment other than CO2 sparging is planned. Page 120