Section 316(b) of the Clean Water Act: Cooling Water Intake Structure Regulations

Consequences for Maryland Power Plants

There are 12 existing power generating facilities in Maryland that have permits allowing for cooling water withdrawals greater than 50 mgd and which would potentially be covered by the Phase II rule. All of these facilities had 316(b) demonstration studies conducted in the late 1970's or early 1980's and all were eventually found to be in compliance with Maryland’s 316(b) requirements. In order to attain compliance, some facilities were required to conduct additional studies to determine the extent of their entrainment and impingement (E&I) impacts and one (Chalk Point) was required to mitigate its impacts. As an EPA-delegated state, in the late 1970s Maryland developed and implemented regulations of cooling water withdrawal and intakes in accordance with EPA guidance on implementation of Clean Water Act Section 316b provided at that time. Code of Maryland Regulations (COMAR) 26.08.03.04-05 establishes procedures for determining adverse environmental impacts due to impingement and entrainment at cooling water intake structures, relative to determination of BTA for minimizing these impacts. These regulations were based on scientific and technical knowledge of the factors influencing the type and magnitude of impacts expected to occur, and followed a logical conceptual framework. The basic elements of that framework include: the evaluation of entrainment impact to a specified level of biological significance; i.e., representative important species (RIS) and spawning and nursery areas of consequence for the RIS a determination of the significance of the entrainment impact that is based on the extent to which the direct effects of the CWIS impact the viability of the RIS population and/or the ecosystem necessary to support its life history functions; the direct effect of the cooling water intake (i.e., the number of fish impinged or entrained) is not the major focus of our regulations; it is the consequence of that effect to the biological entity of concern, whether at the species or the ecosystem level, that establishes what actions the state will take a determination of BTA for impingement based on a simple cost/benefit analysis, comparing the value of fish lost to impingement to the cost for intake restructuring When the Phase II rule is finalized, Maryland will be required to modify COMAR 26.08.03.04-05 to ensure that Maryland’s regulations are consistent with federal regulations. Many of the concepts incorporated by EPA into the new proposed rule could have substantial consequences to the types of cooling water intakes that would be legal for power generating facilities in Maryland, which would be of significance to both the owners of the facilities as well as electricity consumer s in the state. For this reason, Maryland, as represented by Maryland Departments of Environment and Natural Resources, provided extensive comments to EPA on the proposed Phase II rule in August 2002. In the proposed rule, EPA identified a number of issues for which it solicited comments. Maryland provide comments on many of these issues, including, for example, the manner in which cumulative impacts should be evaluated, how ecosystem-level impacts should be accounted for, whether restoration measures should be considered only as a supplement to technology or operational measures or as compensation for adverse impacts of the cooling water system, and the manner in which economic costs and benefits of intake modifications should be assessed. In addition to the specific portions of the proposed rule for which EPA sought comment, Maryland identified a number of issues which were not specifically addressed in the proposed rule that are of particular importance to our state, including for example, the use of out-of-kind mitigation (e.g., creation of anadromous fish passage as compensation for the loss of forage fish due to entrainment) and the frequency with which NPDES permits should be reviewed. The overall view expressed in Maryland’s comment letter to EPA is that the state continues to believe that a sequential approach to impact assessment is a good generic approach to the issues involved. The steps in such a sequence are: quantify the direct effects of the cooling water withdrawal, establish the biological entities that may be at risk, and assess the significance of the direct effects for causing adverse harm to the target entity . Thus, the State of Maryland presented their view that the State’s existing 316(b) CWIS regulations have been and continue to be protective of the environment and the State’s natural resources and suggested that the Phase II rule include the option of a State’s existing regulations being accepted as satisfying 316b requirements. The State’s letter also strongly supported a site-specific approach for determining BTA to minimize Adverse Environmental Impacts (AEI), and the view that AEI should be considered at the species or ecosystem-effects levels and not be simply based on the numbers of organisms entrained and impinged. EPA’s current Phase II schedule calls for final action by February 2004. The extent to which Maryland’s comments will have been taken into account will become evident at that time.

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