While the 316(b) language has been criticized for its lack of detail, the
site-specific nature of many fish population impacts may imply that any
comprehensive definitions of BTA and AEI will be equally generic. Hence
for 316(b), the scientific problem of assessing the impacts on fish of entrainment and impingement may depend, in part, on local AEI definitions. The
scientists involved in modeling, therefore, may be implicitly or explicitly
tasked with both characterizing AEI and helping decide how best to assess
it on a site-specific basis. A decision analysis approach in which values,
endpoints, and associated measures and decision criteria are identified and
developed on a site-specific basis may be preferable to approaches that
assume no need for further learning (Gregory et al. 1993). Such an approach is also consistent with a broader perspective, that ecological decision making almost always depends on local biological context (National
Research Council 1986). At the same time, industry proponents of a
flexible, site-specific 316(b) approach (Utility Water Act Group 2000) have
to recognize that a rule stating “take a local, risk-based approach” implies
an open-ended process and has its own risks.
A final factor contributing to site-specific assessments of entrainment and
impingement is that 316(b) determinations occur in a regulatory setting. In
this setting, the rules of engagement are dictated by lawyers who are likely
to respond differently than scientists to perceived advocacy opportunities.
Given that retrofitted natural-draft cooling towers can cost more than $100
million, the economics of BTA causes the assessments to be contentious,
litigated, and increasingly complex as cases remain unresolved for long
periods of time. The cumulative effect of the above site-specific factors
accounts for the surprising variety and uses of modeling approaches. We
see this variety as a virtue, reflecting local decision-making practices. Such
flexibility can be open to abuse, but the EPA’s role also can be to monitor
decision-making practices to ensure global fairness and integrity. Clearly,
such a role is needed if detailed 316(b) regulations resist codification, as
they have for decades.
3.5 Decision Making and EPA’s
Ecological-Risk-Assessment Process
To increase the effectiveness of science and modeling as part of the 316(b)
decision-making process, it would be constructive if assessments adhered to
an accepted overall risk assessment process. This recommendation means
that an adequate process would be defined for posing appropriate scientific
questions and for being able to adaptively learn from the answers. It does
not mean that all data, modeling choices, and other steps in the process
are determined in advance. The EPA ecological-risk-assessment process
provides such a framework (Figure 3.4). Alternative approaches are used
in other countries and by other organizations within the United States.
60
Webb Van Winkle and John Kadvany
site-specific nature of many fish population impacts may imply that any
comprehensive definitions of BTA and AEI will be equally generic. Hence
for 316(b), the scientific problem of assessing the impacts on fish of entrainment and impingement may depend, in part, on local AEI definitions. The
scientists involved in modeling, therefore, may be implicitly or explicitly
tasked with both characterizing AEI and helping decide how best to assess
it on a site-specific basis. A decision analysis approach in which values,
endpoints, and associated measures and decision criteria are identified and
developed on a site-specific basis may be preferable to approaches that
assume no need for further learning (Gregory et al. 1993). Such an approach is also consistent with a broader perspective, that ecological decision making almost always depends on local biological context (National
Research Council 1986). At the same time, industry proponents of a
flexible, site-specific 316(b) approach (Utility Water Act Group 2000) have
to recognize that a rule stating “take a local, risk-based approach” implies
an open-ended process and has its own risks.
A final factor contributing to site-specific assessments of entrainment and
impingement is that 316(b) determinations occur in a regulatory setting. In
this setting, the rules of engagement are dictated by lawyers who are likely
to respond differently than scientists to perceived advocacy opportunities.
Given that retrofitted natural-draft cooling towers can cost more than $100
million, the economics of BTA causes the assessments to be contentious,
litigated, and increasingly complex as cases remain unresolved for long
periods of time. The cumulative effect of the above site-specific factors
accounts for the surprising variety and uses of modeling approaches. We
see this variety as a virtue, reflecting local decision-making practices. Such
flexibility can be open to abuse, but the EPA’s role also can be to monitor
decision-making practices to ensure global fairness and integrity. Clearly,
such a role is needed if detailed 316(b) regulations resist codification, as
they have for decades.
3.5 Decision Making and EPA’s
Ecological-Risk-Assessment Process
To increase the effectiveness of science and modeling as part of the 316(b)
decision-making process, it would be constructive if assessments adhered to
an accepted overall risk assessment process. This recommendation means
that an adequate process would be defined for posing appropriate scientific
questions and for being able to adaptively learn from the answers. It does
not mean that all data, modeling choices, and other steps in the process
are determined in advance. The EPA ecological-risk-assessment process
provides such a framework (Figure 3.4). Alternative approaches are used
in other countries and by other organizations within the United States.
60
Webb Van Winkle and John Kadvany