1622 E MARINE VIEW DR WHOLE SITE 2022-02-01

water. Both untreated stormwater storage requirements, and adequate post- . treatment flow control must be achieved. The post -treatment flow control pond's revised dimensions must be entered into the WWHM and the WWHM must be run to confirm compliance with the flow control requirement. Maintenance Monitoring: At a minimum, the following monitoring shall be Standards conducted. Test results shall be recorded on a daily log kept on site. Additional testing may be required by the NPDES permit based on site conditions. Operational Monitoring: • Total volume treated and discharged. • Flow must be continuously monitored and recorded at not greater than 15-minute intervals. • Type and amount of chemical used for pH adjustment. • Amount of polymer used for treatment. • Settling time. Compliance Monitoring: • Influent and effluent pH, flocculent chemical concentration, and turbidity must be continuously monitored and recorded at not greater than 15-minute intervals. pH and turbidity of the receiving water. Biomonitoring: 0 Treated stormwater must be non -toxic to aquatic organisms. Treated stormwater must be tested for aquatic toxicity or residual chemicals. Frequency of biomonitoring will be determined by Ecology. Residual chemical tests must be approved by Ecology prior to their use. If testing treated stormwater for aquatic toxicity, you must test for acute (lethal) toxicity. Bioassays shall be conducted by a laboratory accredited by Ecology, unless otherwise approved by Ecology. Acute toxicity tests shall be conducted per the CTAPE protocol. Discharge Compliance: Prior to discharge, treated stormwater must be sampled and tested for compliance with pH, flocculent chemical concentration, and turbidity limits. These limits may be established by the Construction Stormwater General Permit or a site -specific discharge permit. Sampling and testing for other pollutants may also be necessary at some sites. pH must be within the range of 6.5 to 8.5 standard units and not cause a change in the pH of the receiving water of more than 0.2 standard units. Treated stormwater samples and measurements shall be taken from the discharge pipe or another location representative of the nature of the treated stormwater discharge. Samples used for determining compliance with the water quality standards in the receiving water shall not be taken from the treatment pond prior to decanting. Compliance with • the water quality standards is determined in the receiving water. Volume H— Construction Stormwater Pollution Prevention - August 2012 4-117