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Stormwater Pollution Prevention Plan <br /> performance standard for acute toxicity is no statistically significant difference in <br /> survival between the control and 100 percent chemically treated stormwater. <br /> Acute toxicity tests shall be conducted with the following species and protocols: <br /> ' ■ Fathead minnow, Pimephales promelas(96 hour static-renewal test, <br /> method: EPA/600/4-90/027F). Rainbow trout, Oncorhynchus mykiss <br /> (96 hour static-renewal test, method: EPA/600/4-90/027F) may be used <br /> as a substitute for fathead minnow. <br /> Daphnid, Ceriodaphnia dubia, Daphnia pulex, or Daphnia magna (48 hour <br /> static test, method: EPA/600/4-90/027F). <br /> ' All toxicity tests shall meet quality assurance criteria and test conditions in the most recent <br /> versions of the EPA test method and Ecology Publication#WO-R-95-80, Laboratory Guidance <br /> and Whole Effluent Toxicity Test Review Criteria. <br /> 1 Bioassays shall be performed on the first five batches and on every tenth batch thereafter, or as <br /> otherwise approved by Ecology. Failure to meet the performance standard shall be immediately <br /> reported to Ecology. <br /> Discharge Compliance: Prior to discharge, each batch of treated stormwater must be <br /> ' sampled and tested for compliance with pH and turbidity limits. These limits may be <br /> established by the water quality standards or a site-specific discharge permit. Sampling and <br /> testing for other pollutants may also be necessary at some sites. Turbidity must be within <br /> 5 NTUs of the background turbidity. Background is measured in the receiving water, upstream <br /> from the treatment process discharge point. pH must be within the range of 6.5 to 8.5 standard <br /> units and not cause a change in the pH of the receiving water of more than 0.2 standard units. <br /> It is often possible to discharge treated stormwater that has a lower turbidity than the receiving <br /> water and that matches the pH. <br /> ' Treated stormwater samples and measurements shall be taken from the discharge pipe or <br /> another location representative of the nature of the treated stormwater discharge. Samples <br /> used for determining compliance with the water quality standards in the receiving water shall not <br /> be taken from the treatment pond prior to decanting. Compliance with the water quality <br /> standards is determined in the receiving water. <br /> Operator Training <br /> Each contractor who intends to use chemical treatment shall be trained by an experienced <br /> contractor on an active site for at least 40 hours. <br /> IStandard BMPs <br /> Surface stabilization BMPs should be implemented on site to prevent significant erosion. All <br /> sites shall use a truck wheel wash to prevent tracking of sediment off site. <br /> ' 17 16580.006.doc <br />