Clark County Natural Resources Council v. Clark County

MEMORANDUM **

In its complaint, the Clark County Natural Resources Council identified three dozen or so variances between the County’s code, as revised, and the PSB Manual, each of which the Council contends violates the equivalency requirement of the County’s discharge permit. Washington’s Department of Ecology wrote that the revised code meets the requirements of the County’s discharge permit. Ecology’s one-page letter acknowledged that there were “differences” between the revised code and the PSB Manual but found that “these differences do not affect the ‘equivalency’ of the ordinances.” The district court concluded that Ecology’s interpretation of its own term — “equivalent to” — was entitled to “great deference,” and therefore declined “to perform a meticulous review of [the County’s] [c]ode revisions and compare them to the [PSB Manual].” The district court agreed with Ecology’s equivalency determination but did not otherwise discuss its reasonableness.

We have previously held that a state agency’s interpretation of a state-issued NPDES permit is entitled to “substantial deference.” 1 However, Ecology’s determination that the County’s revised code is “equivalent to” the…