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

Abstract

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'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 ≈ ≈ ≈ ≈ 550 adult females per year, AEL ≈ ≈ ≈ ≈ 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. Ehrler et al.: Cooling Water System Entrainment TheScientificWorldJOURNAL (2002) 2(S1), 81-105

An alarming picture of larval fish assemblages entrained into the cooling system of the Kozienice Power Plant (Poland) revealed by DNA metabarcoding

“…Passive participation in drift makes ELH particularly vulnerable to a number of anthropogenic pressures, including alterations in riverbed morphology resulting in the loss of shallow inshore habitats (Pander et al, 2017), the disruption of longitudinal connectivity (Pavlov et al, 2020), and siltation of coarse bottom substrates from restricted water velocities stemming from damming (Nagel et al, 2020). Anthropogenic pressure also includes entrainment into various water-intake structures, e.g., flow-through cooling systems of power plants (Ehrler et al, 2002;Newbold and Iovanna, 2007; for discussion see Barnthouse, 2013) resulting in considerable loses of drifting newly hatched larvae and fry.…”