A California court recently struck down the numeric effluent limits (NEL) on turbidity and pH in the statewide General Permit for Stormwater Discharges Associated with Construction and Land Disturbance Activities (CGP). The Sacramento County Superior Court found that the California State Water Resources Control Board (Board) developed technology-based effluent limits (TBEL) – also called numeric effluent limits or NEL –without adherence to the factors outlined in the Clean Water Act (CWA) Section 304(b). The CGP limits are now invalid and unenforceable.
This lawsuit sheds light on the type and specificity of information required to support the imposition of numeric requirements on construction site owners and operators. See California Building Industry Association, et al. v. State Water Resources Control Board, Sacramento County Superior Court Case No. 34-2009-80000338 – click here. Perhaps the two most important paragraphs (pp. 15-16) that explain the court's reasoning are:
The CWA requires the Board, in developing a TBEL, to determine "the degree of effluent reduction attainable through the application of the best conventional pollutant control technology" (BCT)(33 CFR. §§ 1314(b)(4)(A) and 1342(a)(1)). (Because the TBELs challenged in this case limit the conventional pollutants of stormwater turbidity and pH, BCT is the applicable technological standard – per the CWA and associated regulations.) To comply with this CWA requirement, at a minimum, the Board must identify available technologies, gather data characterizing the performance of the technologies under various site conditions, and derive a numeric TBEL or NEL for turbidity consistent with the performance data. The Board cannot properly base a turbidity NEL on theory and inferences drawn from limited or inconclusive studies of BCT performance using best professional judgment.
Until an attainable turbidity value is derived from performance data for available technologies, individual construction projects subject to the turbidity NEL in the CGP are not able to select suitable technologies to carry out their obligations to control sediment discharges with reasonable assurance that the technologies are capable of achieving the turbidity NEL. Moreover, until an attainable turbidity value is derived, the technical aspects and cost-benefits of the BCT cannot be assessed in accordance with the multi-factor analysis required by the CWA.
The Board has until January 31, 2012, to decide whether to appeal the decision. If and when new turbidity and pH numeric limits are adopted, the Board must also determine the appropriate size of a compliance storm event exemption from the effluent limits.
Background
The addition of numeric limits to construction stormwater discharge permits has been an issue of significant concern to the regulated construction community. The CWA prohibits the discharge of sediment from active construction sites without coverage under a U.S. Environmental Protection Agency (EPA) or state-authorized National Pollutant Discharge Elimination System (NPDES) permit. The CWA sets very specific requirements for how numeric limits may be developed and incorporated into NPDES permits.
In 1999, California finalized a general NPDES permit to regulate stormwater runoff from construction sites (CGP). The permit did not include numeric limits, but instead included narrative limits that prescribed best management practices for controlling turbidity and pH in stormwater runoff. In 2009, California revised its CGP to include numeric limits for turbidity and pH for certain high risk construction projects.
Construction Industry Challenge
The California Building Industry Association (CBIA) challenged the numeric limits, arguing that the Board had not supported them with adequate evidence and had failed to evaluate the control technology as required by the CWA. The court agreed with CBIA and ruled that the numeric limits were invalid and unenforceable.
Specifically, the court found that to set a numeric limit, the Board was required to (1) identify available control technologies, (2) collect data characterizing the performance of those control technologies under various site conditions, and (3) set a numeric limit that that is consistent with the performance data. In addition, pursuant to the CWA, the State Board was required to conduct a multi-factor analysis to assess the effectiveness of the control technology.
In establishing the turbidity limit, the Board relied on three scientific studies, but the court decided the studies were limited and inconclusive and did not support the numeric limit. The first study analyzed turbidity levels in waters receiving stormwater runoff. But the study did not address turbidity levels in stormwater discharges—the relevant consideration—and therefore could not provide support for the numeric limit. The second study reported turbidity data from California construction sites; however it did not indicate which management practices were in place at those sites to control stormwater discharges. Thus, the data could not have helped the Board identify an appropriate and achievable numeric limit. The third study did provide performance data for control technologies, but the study only focused on three highway construction sites in Washington. The court found that the study "may not reflect the variety of soil, rainfall, and topography conditions at California construction sites," and therefore could not adequately support the numeric limit.
In establishing the pH limit, the Board relied on a Caltrans study that determined the mean pH of runoff from highway construction sites in California. This study identified the best management practices that were in place, but it did not analyze the effect of the management practices on pH levels. Thus, the study did not provide the required performance data, and the numeric limit had "no demonstrated relationship to management practices."
The court concluded that the turbidity and pH limits were not supported by substantial evidence because the Board did not justify them with performance data for the chosen control technology. Moreover, because there was no performance data, it was impossible for the Board to analyze factors such as the technology's capability to reduce discharges and its relative costs and benefits, as required by the CWA.
For more information, contact Leah Pilconis at pilconisl@agc.org.
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The information presented in this article should not be construed to be formal legal advice by the Associated General Contractors of America. Because of the changing nature of this area of the law and the importance of individual facts, readers are encouraged to seek independent counsel for advice regarding their individual legal issues.