In a legal victory for the California Building Industry Association (CBIA), the California  Superior Court, County of Sacramento on Dec. 23 ruled against the state’s Construction General Permit for its Numeric Effluent Limits (NELs) for turbidity (amount of sediment) and pH (acidity) in stormwater discharges.

The court invalidated the numeric effluent limits because the state failed to identify a technology that could consistently meet them.

The State Water Resource Control Board imposed the NELs in its General Permit for Stormwater Discharges Associated With Construction and Land Development Activities.

The court’s ruling — in California Building Industry Association, et al. v. State Water Resources Control Board — shows that the board did not have enough actual performance data from construction sites to support the Numeric Effluent Limits.

California is one of the few states to have adopted an NEL for turbidity and pH in its building permit.

The California builders argued that the state’s inability to establish an attainable turbidity value from performance data for available technologies left builders with no reasonable assurance that the technology they chose to control sediment discharges would be able to achieve the required turbidity NEL.

The decision in California could have ramifications for the Environmental Protection Agency’s current efforts to develop Numeric Effluent Limits.

The EPA has yet to identify a technology that can consistently meet any set numeric value across all conditions and soil types and is hoping to gather performance data from the public that will enable it to develop an NEL for turbidity.

A related story in this issue of Nation's Building News looks at the EPA's latest effort to obtain data on construction stormwater discharges.

For more information, email Ty Asfaw at NAHB, or call her at 800-368-5242 x8124.