The Solicitor of the Interior Department has just released this memo, which sets forth the Solicitor's opinion as to the nature and extent of the Service's power to exclude otherwise qualifying areas from critical habitat under Section 4(b)(2) of the Act, 16 U.S.C. s. 1533(b)(2). The exclusion power has long been a source of litigation, for both sides of the ideological spectrum—the Right complaining about the Service's underestimation of economic impacts, and the Left complaining about the Service's overestimation of impacts as well as existing conservation measures.
In the days to follow, more analysis will be posted on the meaning of the memo, but from a first-blush review, the most interesting position staked out in the memo is the assertion that, when determining whether to exclude an area from the designation on the basis of economic costs, the Service may not take into account coextensive costs, i.e., costs that would fully occur even in the absence of the designation. This position is in some tension with the Tenth Circuit's decision in New Mexico Cattle Growers.