Correspondence/Rebuttal pubs.acs.org/est
Comment on “Wildlife and the Coal Waste Policy Debate: Proposed Rules for Coal Waste Disposal Ignore Lessons from 45 years of Wildlife Poisoning”
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of the AFS replacement costs for small fish are far below $1 per fish. As an example of another methodological flaw, L&S double count the replacement cost of harvestable sport fish. For example, L&S estimate the replacement cost for all dead fish for incident #12 (Melton Hill Reservoir) in their Ecological Damages category and then use 20% of that estimate for the replacement cost of dead harvestable sport fish in their Recreational Damages category. Consequently, the replacement cost for dead harvestable sport fish is double counted.
INTRODUCTION emly and Skorupa present estimates of fish and wildlife damages for 22 releases of coal combustion waste (CCW) from surface impoundments or landfills.1 They claim that the 22 incidents caused $2.31 billion in damages. Lemly & Skorupa (L&S) also estimate that future CCW incidents will cause an additional $3.85 billion in damages over the next 50 years. In this Comment I summarize several serious flaws in L&S’s assessment of fish and wildlife damages, which indicate that they have substantially overstated such damages. I provide more detail on these and other flaws in a separate report.2
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ERRORS IN TABLE 2 Table 2 in L&S’s article provides a breakdown of the damages for the 22 CCW incidents on an annual basis. They use the 75th percentile of the annual damages between 1967 and 2010 to project damages into the future over the next 50 years, which is the $3.85 billion estimate at the bottom of Table 2. L&S provide two justifications for using the 75th percentile of their annual damages in their projection of future damages. First, they claim that the ecological damages began earlier and extended longer than their injury period for most of the CCW incidents. Second, they focus mostly on damages to fish for most of the CCW incidents, excluding damages to other aquatic organisms and birds. Thus, L&S conclude that their damage estimates are underestimates, and “the 75th percentile is a reasonable and conservative number for use in projecting future [damages].”1 At least one CCW incident (#17, Martins Creek) had a much shorter damage period than in L&S’s assessment and a shorter damage period is likely for at least two other incidents.2 Furthermore, the flaws in L&S’s assessment, which I discuss in more detail in ref 2, do not support their conclusion that they have underestimated damages for the 22 CCW incidents. Even if it was appropriate for L&S to use the 75th percentile of their annual damages, their projection of $3.85 billion in future damages has two serious flaws. First, the $3.85 billion is not a present value, it is approximately 50 times the 75th percentile estimate of annual damages (i.e., $76.97 million). If the 75th percentile estimate was a present-value measure of annual damages, which it is not, then the present value of those annual damages over 50 years would be $1.98 billion using a 3% discount rate (about half of L&S’s estimate). A 3% discount rate is commonly used in present-value calculations when assessing natural resource damages under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Oil Pollution Act (OPA).4 Second, it is not appropriate to use an average measure of annual damages over a long period of time (e.g., 1967−2010) while ignoring a clear trend in annual damages. I converted L&S’s annual damages in their Table 2 into present value terms
LACK OF SUPPORT ON SOME DAMAGES L&S estimate aesthetic damages and “stress and anxiety” damages for some CCW incidents, but they provide no evidence in their Supporting Information that such damages actually occurred. Furthermore, L&S estimate such damages by assuming that 20% of the population living within 30 miles of the release site experienced the damages, but they provide no support or rationale for those assumptions − they are arbitrary.
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METHODOLOGICAL FLAWS ON SOME DAMAGES There are methodological flaws in several of L&S’s damage categories. For example, they estimate damages for dead fish resulting from CCW incidents by multiplying the number of dead fish times a replacement cost of $1 per fish. L&S estimate the number of dead fish as one-half of the preincident standing crop of fish times the number of years of greatest toxicity in the damage period. Thus, if there are 10 years of high toxicity following an incident, then the number of dead fish in the L&S assessment is 5 times the preincident standing crop of fish. In addition to providing no technical support for this approach to estimating dead fish over time, L&S’s approach is inconsistent with American Fisheries Society guidelines for estimating fish kills following contaminant releases.3 Furthermore, it is unlikely that the number of dead fish over 10 years could be 5 times the preincident standing crop of fish, because this multiple suggests relatively high annual reproduction rates for fish purportedly exposed to highly toxic substances on a continuing basis. Even if L&S’s estimate was accurate, most of the fish killed in years 2 through 10 would be less than 2 years old. The replacement cost for such young fish would be relatively small, as explained below L&S obtain their replacement cost of $1 per fish from the American Fisheries Society (AFS).3 There are several economic reasons that replacement costs may overstate damages.2 Even if replacement costs are the proper measure of damages, the AFS replacement costs vary substantially by species and the size of fish, but L&S do not estimate the number of dead fish by species or size. Therefore, the L&S estimate of dead fish cannot be matched to the AFS replacement costs. Furthermore, most © 2013 American Chemical Society
Published: April 18, 2013 11365
dx.doi.org/10.1021/es304745z | Environ. Sci. Technol. 2013, 47, 11365−11366
Environmental Science & Technology
Correspondence/Rebuttal
and calculated average annual damages for five-year increments from 1970−2010.2 After peaking in the early 1980s, average annual present-value damages have fallen consistently over the last 30 years. Such a trend should be taken into account when projecting annual damages into the future. For example, the present value of damages over 50 years using the average annual damages for the last 10 years is just 38% of L&S’s projection.
Richard W. Dunford*
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Environmental Economics Services, Raleigh, North Carolina 27607, United States
AUTHOR INFORMATION
Corresponding Author
*Phone: 919-827-3360; e-mail:
[email protected]. Notes
The author declares the following competing financial interest(s): Funding for this Comment was provided by the Utility Solid Waste Activities Group. However, the conclusions in the Comment are the author’s.
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REFERENCES
(1) Lemly, A. Dennis; Joseph, P. Skorupa Wildlife and the coal waste policy debate: proposed rules for coal waste disposal ignore lessons from 45 years of wildlife poisoning. Environ. Sci. Technol. 2012, 46 (16), 8,595−8,600. (2) Dunford, R. W. A Critical Review of the 2012 Lemly & Skorupa Article in Environmental Science & Technology: Final Report; Environmental Economics Services: Raleigh, NC, 2012. (3) Investigation and Monetary Values of Fish and Freshwater Mussel Kills, Special Publication 30; Southwick, R. I., A. J. Loftus, Eds.; American Fisheries Society: Bethesda, MD, 2003. (4) Discounting and the Treatment of Uncertainty in Natural Resource Damage Assessment, Technical Paper 99-1; National Oceanic and Atmospheric Administration, Damage Assessment Center: Silver Spring, MD, 1999.
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dx.doi.org/10.1021/es304745z | Environ. Sci. Technol. 2013, 47, 11365−11366
