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Comments and Suggested Changes to the Construction Stormwater General Permit June 4 th 2008 Presented by the Active Treatment Systems Workgroup. ATS Workgroup. Applauds the SWRCB for this process. Who, What, Why Who makes up the ATS Workgroup ProTech General Contracting Services
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Comments and Suggested Changesto theConstruction Stormwater General PermitJune 4th 2008Presented by theActive Treatment Systems Workgroup
ATS Workgroup Applauds the SWRCB for this process.
Who, What, Why • Whomakes up the ATS Workgroup • ProTech General Contracting Services • Clear Creek Systems • Clear Water Compliance Services • HaloSource • What we are presenting • Why ATS is beneficial on construction sites
What we are presenting • History of ATS Regulation • CA CVRWQCB Guidance Document • WA DOE Technical Review Committee • Final Draft GCP guidelines - positive • Safeguarding with automated monitoring • Trained and certified operators • Residual testing for chemical additives
What we are presenting continued • ATS Feasibility • Influent/Effluent Data with Percent Reduction • Economic Feasibility • ATS Capabilities • Recommendations
Aquatic Impacts of Turbidity Source: http://www.lakeaccess.org/russ/turbidity.htm
Mortality, Reproduction and Behavioral and the Impact of Suspended Solids Lethal Effects - Mortality Rainbow Trout – (Acute) 200 mg/L for 24 hr leads to 5% mortality in fry Rainbow Trout – (Chronic) 21 mg/L for 48 days leads to 62% reduction in egg-to-fry survival Chinook Salmon – (Acute) 82k mg/L for 6 hr leads to 60% mortality of juveniles Chinook Salmon – (Chronic) 488 mg/L for 8 days leads to 50% mortality of smolts Sublethal Effects - Reproduction CutthroatTrout – 35 mg/L for 2 hr leads to feeding ceased, cover sought Coho Salmon – 300 mg/L for 1 hr leads to feeding ceased Behavioral Effects – Modified Behaviors Whitefish – 0.7 mg/L for 1 hr leads to overhead cover abandoned Arctic Greyling – 100 mg/L for 1 hr leads to avoidance response C.P. Newcombe,. and D.D. MacDonald. 1991. Effects of Suspended Sediments on Aquatic Ecosystems. North American Journal of Fisheries Management 11:72-82. 1991
Aquatic Impacts of Turbidity Source: Newcombe, 2003, in OR DEQ 2005
Recommendations • 1000 NTU NEL should be reduced • Example: • Consider a 500 gpm flow at 1000 NTU, 8 hours a day for a 5 day week. Assume 1000 NTU = 1000 mg/L TSS (this is a conservative assumption). • 500 gpm x 60 min x 8 hrs x 5 days = 1.2 Million gal per week • 1000 mg/L x 3.8 L/gal = 3800 mg/gal • 1.2 M gal x 3800 mg/gal = 4560 kg or about 10,000 lbs • Assume a sediment density of 60 lbs/ft3 • 10,000 lbs/60 lbs/ft3 = 167 ft3 • This equals around 2 Cubic Yards of sediment/week or a standard dump truck per month.
Recommendations • Attachment J should be removed • Attachment E, page 1, 3.a • Current: “Active Treatment Systems will be designed and approved by qualified personnel: CPESC, CPSWQ, registered civil or other professional engineers with a minimum of 10 years demonstrated construction stormwater treatment system design experience. ” • Recommendation:…”CPESC, CPSWQ, registered civil engineer, professional engineer, or others with a minimum”…
Recommendations • Attachment E, page 1.3.d • Current: “The discharger shall install and operate their ATS using personnel with either a minimum of five years construction storm water experience or are licensed contractors specifically holding a California Class A Contractors license.” • Recommendation: “The ATS installation and operation firm shall have five years construction storm water experience or be licensed contractors specifically holding a class A contractors license and all operational personnel must meet minimum training criteria listed herein.”
Why ATS beneficial on construction sites • Turbidity Reduction • And other contaminants associated • Dirty Water vs. Watery Dirt • ATS is in addition to traditional BMP measures • Allows year round construction • Aquatic Life • Going Forward • New and Innovative Technologies