Clean Water Act Sections 316 (a) & (b

CEC staff provides in-depth knowledge of CWA Section 316 and a broad experience base in performing the tasks related to the complexities of the ruling. CEC owns and operates the equipment required for the extensive assessment and field studies associated with 316 studies.

CEC staff provides in-depth knowledge of CWA Section 316 and a broad experience base in performing the tasks related to the complexities of the ruling. CEC owns and operates the equipment required for the extensive assessment and field studies associated with 316 studies.

Section 316(a) of the Clean Water Act (CWA) allows for a variance from applicable thermal limitations to surface water if the permittee can demonstrate that the balanced indigenous community of aquatic organisms is protected and maintained.

Section 316(b) of the CWA requires the determination of whether the withdrawal of cooling water causes or has the potential to cause adverse environmental impacts on aquatic populations and communities.

Section 316(a) Services

CEC staff has worked closely with utility clients and regulatory agencies in obtaining 316(a) variances for the temperature limitations imposed on cooling water discharges. Typically, the 316(a) demonstration includes the following components: characterization of the generating station and its operation; characterization of the receiving waterbody: selection and description of representative important species (RIS); hydrothermal assessment; and biothermal assessment.

Hydrothermal Assessment: CEC has the field equipment (e.g., boats, thermistors, current meters) needed to collect the time series of temperature, current speeds, and other data at several locations in the waterbody.

As described above, CEC also has the hydrographic equipment to measure the bathymetry of the waterbody within the vicinity of a generating station.  IN-situ moorings can also be established to continuously measure a variety of parameters (e.g., temperature, DO). The field survey data can then be used in the calibration and verification of the models (e.g., CORMIX, RMA-10) selected to calculate the fate and transport of the thermal discharge in the water body under different station operations and waterbody conditions (i.e., seasons, stream flows).

Biothermal Assessment: CEC has personnel familiar with EPA's approach to addressing 316(a) that is based on draft guidance manuals (1975, 1977), prior practices and recent ecological risk assessment guidance (1997, 1998). Typically, the process includes a review of regulatory standards/ criteria; evaluation of the vulnerability of different biotic categories; selection of RIS; predictions of biothermal impact based on predictive and retrospective evaluations; and an evaluation of whether the BIC is protected and maintained.

Section 316(b) Services

CEC staff is experienced in producing the environmental information and reports that will be needed by utilities in their 316(b) filings to federal and state regulatory agencies.

Typically, the review process is initiated by the agency reviewing the National Pollutant Discharge Elimination System (NPDES) permit renewal application for a generating station, which would include a Comprehensive Demonstration Study (CDS) with associated reports and/or plans for most facilities or in some cases a Technology Installation and Operation Plan (TIOP). The CDS may include the following: a proposal for data/information collection; physical data to characterize the source waterbody and cooling water intake structure (CWIS) design and operation data; impingement mortality and entrainment characterization study information; design and construction (D&C) technology plan; restoration measures; site-specific economic evaluations; and a verification monitoring plan, as appropriate.

CEC staff can produce reports that clearly identify existing or proposed technology, operational or restoration measures that may be used for a station to demonstrate that the best technology available (BTA) is employed to satisfy regulatory requirements. We have the capability to produce the biological data/information required for the 316(b) filings. The economic and engineering aspects of the 316(b) work will be subcontracted to a consultant acceptable to the client.

CEC realizes that it is important to produce reports that are concise, clear, documented, and factually correct in order to facilitate and expedite the subsequent regulatory and public review process.

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