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e. The Permittee may discontinue sampling at discharge points in areas of the <br /> project where the Permittee no longer has operational control of the construction <br /> activity. <br /> 4. Sampling and Analysis Methods <br /> a. The Permittee performs turbidity analysis with a calibrated turbidity meter <br /> (turbidimeter) either on site or at an accredited lab. The Permittee must record <br /> the results in the site log book in nephelometric turbidity units (NTUs). <br /> b. . The Permittee performs transparency analysis on site with a 13/4-inch-diameter, <br /> 60-centimeter (cm)-long transparency tube. The Permittee will record the results <br /> in the site log book in centimeters (cm). <br /> Table 4: Monitoring and Reporting Requirements <br /> -Parameter knit ` nalytical Method Sampling . '! .Benchmark Phone .. <br /> Frequency Value Reporting <br /> Trigger Value '. <br /> Turbidity NTU SM2130 Weekly, if 25 NTUs 250 NTUs <br /> discharging <br /> Transparency cm Manufacturer Weekly, if 33 cm 6 cm <br /> instructions, or discharging <br /> Ecology guidance <br /> 5. Turbidity/Transparency Benchmark Values and Reporting Triggers <br /> The benchmark value for turbidity is 25 NTUs or less. The benchmark value for <br /> transparency is 33 centimeters (cm). Note: Benchmark values do not apply to <br /> discharges to segments of water bodies on Washington State's 303(d) list <br /> (Category 5) for turbidity, fine sediment, or phosphorus; these discharges are <br /> subject to a numeric effluent limit for turbidity. Refer to Special Condition S8 for <br /> more information. <br /> a. Turbidity 26—249 NTUs, or Transparency 32—7 cm: <br /> If the discharge turbidity is 26 to 249 NTUs; or if discharge transparency is <br /> less than 33 cm, but equal to or greater than 6 cm, the Permittee must: <br /> i. Review the SWPPP for compliance with Special Condition S9 and make <br /> appropriate revisions within 7 days of the date the discharge exceeded the <br /> benchmark. <br /> ii. Immediately begin the process to fully implement and maintain <br /> appropriate source control and/or treatment BMPs as soon as possible, <br /> addressing the problems within 10 days of the date the discharge <br /> exceeded the benchmark. If installation of necessary treatment BMPs is <br /> not feasible within 10 days, Ecology may approve additional time when <br /> the Permittee requests an extension within the initial 10-day response <br /> period. <br /> Construction AStor°tanvater°General Perinit <br /> Page 17 <br />