Moreover, as Professor May indicates, citizen enforcement of the federal environmental statutes has tended to emphasize the CWA. As he notes, almost all citizen suits noticed between 1978 and 1983 were CWA citizen suits, and, as was true of government enforcement efforts, a significant portion of environmental citizen suits since 1983 have been CWA citizen suits—about 39% of all environmental citizen suits filed in 1994 were CWA citizen suits, 43% in 1995, 38% in 1996, and 38% in 1997.143 When one looks only at pollution-related (non-wildlife) citizen suits, moreover, the percentages are even higher: CWA citizen suits accounted for 41% of all pollution-related citizen suits in 1994, 46% in 1995, 46% in 1996, and 49% in 1997.144 Significantly more CWA citizen suits are filed every year than citizen suits under any other single federal environmental statute.145

143. John Scalia, Bureau of Justice Statistics, U.S. Dep’t of Justice, Federal Enforcement of
Environmental Laws 1997, at 7 (1999), available at http://www.ojp.usdoj.gov/bjs/pub/pdf/feel97.pdf.
144. Id.
145. Id. In the years 1994-1997, citizens filed 223 to 254 CWA citizen suits each year. Id. In contrast, citizens filed only 130 to 157 Comprehensive Environmental Response, Compensation, and Liability Act suits per year, only 94 to 136 RCRA suits per year, 16 to 28 CAA suits per year, and 24 to 36 wildlife suits (under several statutes) per year. Id.