a threat to water quality because they do not introduce any invasive species from outside the Great Lakes. EPA has properly rejected this argument, noting that Lakers can spread or more rapidly distribute invasive species already present, in the Great Lakes. Id. at 501. 16 . Federal regulation permits such limits to be expressed narratively if the calculation of numeric limits is "infeasible.” 40 C.F.R. § 122.44(k)(3). 17 . EPA also claims general prohibitions can be BMPs, citing 40 C.F.R. § 122.2, but does not offer an example of something as general as the WQBEL standard being found to be a BMP. As discussed herein, the EPA’s charac-terizationis inconsistent with regulations that require WQBELs to "ensure compliance.” 40 C.F.R. § 122.4(d); see Auer, 519 U.S. at 461, 117 S.Ct. 905 (<HOLDING>). 18 . EPA’s response is that petitioners’
holding interpretation may not be inconsistent with regulation holding that where a regulation could not fairly be read to have spoken at all on an issue an agencys proposed interpretation of the regulation as it pertained to that issue was not a reasonable interpretation of the regulation holding that courts should defer to agencys interpretation of its own regulations if not plainly erroneous or inconsistent with the regulation holding that a secretarys interpretation of a departments regulation is controlling unless plainly erroneous or inconsistent with the regulation holding that deference is owed to an agencys interpretation of its own categorical exclusion regulations so long as that interpretation is not plainly erroneous or inconsistent with the regulation