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1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />i <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />flow control must be achieved. The post -treatment flow control pond's revised dimen- <br />sions must be entered into the WWHM and the WWHM must be run to confirm com- <br />pliance with the flow control requirement. <br />Maintenance Standards <br />Monitoring: At a minimum, the following monitoring shall be conducted. Test results <br />shall be recorded on a daily log kept on site. Additional testing may be required by the <br />NPDES permit based on site conditions. <br />Operational Monitoring: <br />• Total volume treated and discharged. <br />• Flow must be continuously monitored and recorded at not greater than 15-minute <br />intervals. <br />• Type and amount of chemical used for pH adjustment. <br />• Amount of polymer used for treatment. <br />• Settling time. <br />Compliance Monitoring: <br />Influent and effluent pH, flocculent chemical concentration, and turbidity must be <br />continuously monitored and recorded at not greater than 15-minute intervals. pH <br />and turbidity of the receiving water. <br />Biomonitoring: <br />Treated stormwater must be non -toxic to aquatic organisms. Treated stormwater must be <br />tested for aquatic toxicity or residual chemicals. Frequency of biomonitoring will be <br />determined by Ecology. <br />Residual chemical tests must be approved by Ecology prior to their use. <br />If testing treated stormwater for aquatic toxicity, you must test for acute (lethal) toxicity. <br />Bioassays shall be conducted by a laboratory accredited by Ecology, unless otherwise <br />approved by Ecology. Acute toxicity tests shall be conducted per the CTAPE protocol. <br />Discharge Compliance: Prior to discharge, treated stormwater must be sampled <br />and tested for compliance with pH, flocculent chemical concentration, and tur- <br />bidity limits. These limits may be established by the Construction Stormwater General <br />Permit or a site -specific discharge permit. Sampling and testing for other pollutants may <br />also be necessary at some sites. pH must be within the range of 6.5 to 8.5 standard units <br />and not cause a change in the pH of the receiving water of more than 0.2 standard units. <br />Treated stormwater samples and measurements shall be taken from the discharge pipe <br />or another location representative of the nature of the treated stormwater discharge. <br />Samples used for determining compliance with the water quality standards in the <br />2014 Stormwater Management Manual for Western Washington <br />Volume 11 - Chapter - Page 403 <br />