Two multimetric indices have been developed to help address fish community (reservoir fish assemblage index [RFAI]) and individual population quality (sport fishing index [SFI]) in Tennessee River reservoirs. The RFAI, with characteristics similar to the index of biotic integrity (IBI) used in stream fish community determinations, was developed to monitor the existing condition of resident fish communities[1,2,3]. The index, which incorporates standardized electrofishing of littoral areas and experimental gill netting for limnetic bottom-dwelling species, has been used to determine residential fish community response to various anthropogenic impacts in southeastern reservoirs.The SFI is a multimetric index designed to address the quality of the fishery for individual resident sport fish species in a particular lake or reservoir[4]. The SFI incorporates measures of fish population aspects and angler catch and pressure estimates. This paper proposes 70% of the maximum RFAI score and 10% above the average SFI score for individual species as &#x201C;screening&#x201D; endpoints for balanced indigenous populations (BIP) or adverse environmental impact (AEI). Endpoints for these indices indicate: (1) communities/populations are obviously balanced indigenous populations (BIP) indicating no adverse environmental impact (AEI), or are &#x201C;screened out&#x201D;; (2) communities/populations are considered to be potentially impacted; and (3) where the resident fish community/population should be considered adversely impacted. Suggestions are also made concerning how examination of individual metric scores can help determine the source or cause of the impact.

Gary D. Hickman

Mary L. Brown

Proposed Methods and Endpoints for Defining and Assessing Adverse Environmental Impact (AEI) on Fish Communities/Populations in Tennessee River Reservoirs

A study to determine the effects of entrainment by the Diablo Canyon Power Plant (DCPP) was conducted between 1996 and 1999 as required under Section 316(b) of the Clean Water Act. The goal of this study was to present the U.S. Environmental Protection Agency (EPA) and Central Coast Regional Water Quality Control Board (CCRWQCB) with results that could be used to determine if any adverse environmental impacts (AEIs) were caused by the operation of the plant&#x2019;s cooling-water intake structure (CWIS). To this end we chose, under guidance of the CCRWQCB and their entrainment technical working group, a unique approach combining three different models for estimating power plant effects: fecundity hindcasting (FH), adult equivalent loss (AEL), and the empirical transport model (ETM). Comparisons of the results from these three approaches provided us a relative measure of confidence in our estimates of effects. A total of 14 target larval fish taxa were assessed as part of the DCPP 316(b). Example results are presented here for the kelp, gopher, and black-and-yellow (KGB) rockfish complex and clinid kelpfish. Estimates of larval entrainment losses for KGB rockfish were in close agreement (FH is approximately equals to 550 adult females per year, AEL is approximately equals to 1,000 adults [male and female] per year, and ETM = larval mortality as high as 5% which could be interpreted as ca. 2,600 1 kg adult fish). The similar results from the three models provided confidence in the estimated effects for this group. Due to lack of life history information needed to parameterize the FH and AEL models, effects on clinid kelpfish could only be assessed using the ETM model. Results from this model plus ancillary information about local populations of adult kelpfish suggest that the CWIS might be causing an AEI in the vicinity of DCPP.

C.P. Ehrler

J.R. Steinbeck

E.A. Laman

J.B. Hedgepeth

J.R. Skalski

D.L. Mayer

A Process for Evaluating Adverse Environmental Impacts by Cooling-Water System Entrainment at a California Power Plant

Equivalent loss models encompass a variety of life table-based approaches that can be used to convert age- and life stage-specific estimates of entrainment and impingement loss to a common, easily understood currency. This common currency can be expressed in terms of numbers of individuals, yield to the fishery, or biomass to the ecosystem. These models have at least two key uses in the Section 316(b) assessment process: screening for adverse environmental impact (AEI) and determination of environmental benefits associated with intake alternatives. This paper reviews the various forms of equivalent loss models, their data input requirements, and their assumptions and limitations. In addition, it describes how these models can be used as a second-level screening tool as part of the assessment of the potential for AEI. Given their relative simplicity and ease of use, equivalent loss models should prove to be an important tool in the arsenal of impact assessment methods for Section 316(b).

William Dey

Use of Equivalent Loss Models Under Section 316(b) of the Clean Water Act

This paper develops a comparative framework for policy proposals involving fish protection and Section 316(b) of the Clean Water Act (CWA). Section 316(b) addresses the impingement and entrainment of fish by cooling-water intake structures used principally by steam electric power plants. The framework is motivated by examining the role of adverse environmental impacts (AEIs) in the context of Section 316(b) decision making. AEI is mentioned in Section 316(b), but not defined. While various AEI options have been proposed over the years, none has been formalized through environmental regulations nor universally accepted. Using a multiple values approach from decision analysis, AEIs are characterized as measurement criteria for ecological impacts. Criteria for evaluating AEI options are identified, including modeling and assessment issues, the characterization of ecological value, regulatory implementation, and the treatment of uncertainty. Motivated by the difficulties in defining AEI once and for all, a framework is introduced to compare options for 316(b) decision making. Three simplified policy options are considered, each with a different implicit or explicit AEI approach: (1) a technology-driven rule based on a strict reading of the 316(b) regulatory text, and for which any impingement and entrainment count as AEI, (2) a complementary, open-ended risk-assessment process for estimating population effects with AEI characterized on a site-specific basis, and (3) an intermediate position based on proxy measures such as specially constructed definitions of littoral zone, sensitive habitat, or water body type. The first two proposals correspond roughly to responses provided, respectively, by the Riverkeeper environmental organization and the Utility Water Act Group to the U.S. Environmental Protection Agency (EPA)&#x2019;s proposed 316(b) new facilities rule of August 2000; the third example is a simplified form of the EPA&#x2019;s proposed August 2000 new facilities rule itself. The simplified policy positions are compared using the three dimensions of the comparative policy framework: (1) the role of CWA philosophy or vision, such as the use of technology-forcing rules, (2) regulatory policy implementation, and (3) the role for scientific information and the knowledge base. Strengths and weaknesses of all three 316(b) policy approaches are identified. The U.S. EPA&#x2019;s final new facilities rule of November 2001 is briefly characterized using the comparative policy framework and used to further illustrate the approach.

John Kadvany

Comparing Clean Water Act Section 316(b) Policy Options

Initially, regulation of cooling water intakes under &#x00A7;316(b) was extremely conservative due to the rapid increase predicted for generating capacity, and to the uncertainty associated with our knowledge of the effects of entrainment and impingement. The uncertainty arose from four main sources: estimation of direct plant effects; understanding of population regulatory processes; measurement of population parameters; and predictability of future conditions. Over the last quarter-century, the uncertainty from the first three sources has been substan-tially reduced, and analytical techniques exist to deal with the fourth. In addition, the dire predictions initially made for some water bodies have not been realized, demonstrating that populations can successfully withstand power plant impacts. This reduced uncertainty has resulted in less conservative regulation in some, but not all venues. New York appears to be taking a more conservative approach to cooling water intakes. The conservative approach is not based on regulations, but in a philosophy that power plant mortality is an illegitimate use of the aquatic resources. This philosophy may simplify permitting decisions, but it does not further the development of a science-based definition of adverse environmental impact.

John R. Young

William P. Dey

Uncertainty and Conservatism in Assessing Environmental Impact under &#x00A7;316(b): Lessons from the Hudson River Case

Section 316(b) of the Clean Water Act (CWA) requires that &#x201C;the location, design, construction, and capacity of cooling water intake structures reflect the best technology available for minimizing adverse environmental impact.&#x201d; As the U.S. Environmental Protection Agency (EPA) develops new regulations to implement Section 316(b), much of the debate has centered on adverse impingement and entrainment impacts of cooling-water intake structures. Depending on the specific location and intake layout, once-through cooling systems withdrawing many millions of gallons of water per day can, to a varying degree, harm fish and other aquatic organisms in the water bodies from which the cooling water is withdrawn. Therefore, opponents of once-through cooling systems have encouraged the EPA to require wet or dry cooling tower systems as the best technology available (BTA), without considering site-specific conditions.However, within the context of the broader scope of the CWA mandate, this focus seems too narrow. Therefore, this article examines the phrase &#x201C;minimizing adverse environmental impact&#x201d; in a holistic light. Emphasis is placed on the analysis of the terms &#x201C;environmental&#x201d; and &#x201C;minimizing.&#x201d; Congress chose &#x201C;environmental&#x201d; in lieu of other more narrowly focused terms like &#x201C;impingement and entrainment,&#x201d; &#x201C;water quality,&#x201d; or &#x201C;aquatic life.&#x201d; In this light, BTA for cooling-water intake structures must minimize the entire suite of environmental impacts, as opposed to just those associated with impingement and entrainment. Wet and dry cooling tower systems work well to minimize entrainment and impingement, but they introduce other equally important impacts because they impose an energy penalty on the power output of the generating unit. The energy penalty results from a reduction in plant operating efficiency and an increase in internal power consumption. As a consequence of the energy penalty, power companies must generate additional electricity to achieve the same net output. This added production leads to additional environmental impacts associated with extraction and processing of the fuel, air emissions from burning the fuel, and additional evaporation of freshwater supplies during the cooling process. Wet towers also require the use of toxic biocides that are subsequently discharged or disposed. The other term under consideration, &#x201C;minimizing,&#x201d; does not equal &#x201C;eliminating.&#x201d; Technologies may be available to minimize but not totally eliminate adverse environmental impacts.

John A. Veil

Markus G. Puder

Debra J. Littleton

Nancy Johnson

A Holistic Look at Minimizing Adverse Environmental Impact Under Section 316(b) of the Clean Water Act

Maryland&#x2019;s cooling-water intake and discharge regulations, the Code of Maryland Regulations (COMAR) 26.08.03, stem from Sections 316(a) and (b) of the Clean Water Act (CWA). COMAR 26.08.03.05 and litigative and administrative rulings stipulate that the location, design, construction, and capability of cooling-water intake structures must reflect the best technology available (BTA) for minimizing adverse environmental impacts (AEIs), providing that the costs of implementing the BTA are not wholly disproportionate to the expected environmental benefits. Maryland law exempts facilities that withdraw less than 10 million gallons/day (MGD) and less than 20% of stream or net flow by the intake. If not exempt, BTA must be installed if the cost of doing so is less than five times the value of fish impinged annually. Through site-specific studies and the use of a Spawning and Nursery Area of Consequence (SNAC) model applied to Representative Important Species, several power plants were evaluated to determine if they have had an adverse effect on spawning and nursery areas of consequence. Examples of application of the Maryland law to a number of power plants in the state are presented, together with the outcome of their evaluation.

Richard McLean

William A. Richkus

Stephen P. Schreiner

David Fluke

Maryland Power Plant Cooling-Water Intake Regulations and their Application in Evaluation of Adverse Environmental Impact

It is sometimes argued that, from an ecological point of view, population-, community-, and ecosystem-level endpoints are more relevant than individual-level endpoints for assessing the risks posed by human activities to the sustainability of natural resources. Yet society values amenities provided by natural resources that are not necessarily evaluated or protected by assessment tools that focus on higher levels of biological organization. For example, human-caused stressors can adversely affect recreational opportunities that are valued by society even in the absence of detectable population-level reductions in biota. If protective measures are not initiated until effects at higher levels of biological organization are apparent, natural resources that are ecologically important or highly valued by the public may not be adequately protected. Thus, environmental decision makers should consider both scientific and societal factors in selecting endpoints for ecological risk assessments. At the same time, it is important to clearly distinguish the role of scientists, which is to evaluate ecological effects, from the role of policy makers, which is to determine how to address the uncertainty in scientific assessment in making environmental decisions and to judge what effects are adverse based on societal values and policy goals.

Elizabeth M. Strange

Joshua Lipton

Douglas Beltman

Blaine D. Snyder

Scientific and Societal Considerations in Selecting Assessment Endpoints for Environmental Decision Making

About this journal

The Scientific World Journal publishes original research and review articles&nbsp;covering a wide range of subjects in science, technology, and medicine.

Journal profile

Meet the editorial board

The Scientific World Journal maintains an Editorial Board of practicing researchers from around the world, to ensure manuscripts are handled by editors who are experts in the field of study.

Editor spotlight

Submit your proposal

Do you think there is an emerging area of research that really needs to be highlighted? Or an existing research area that has been overlooked or would benefit from deeper investigation? Raise the profile of a research area by leading a Special Issue.

Special Issues

Author guidelines

Editorial board

Databases and indexing

title

The Scientific World Journal publishes original research and review articles covering a wide range of subjects in science, technology, and medicine.

description

https://images.hindawi.com/journals/tswj/tswj.banner.jpg

twitter:card

twitter:description

twitter:site

twitter:title

twitter:url

twitter:image

The Scientific World Journal | Hindawi

The Scientific World Journal

This Issue is now open for submissions.
Papers are published upon acceptance, regardless of the Special Issue publication date.