Santa Cruz River is Navigable But Broader CWA Issue Unresolved

The Environmental Protection Agency has decided that two segments of the Santa Cruz River are in fact navigable. The issue was left unsettled after the U.S Army Corps of Engineers revoked its original May 30 determination of navigability pending further review. This raised statewide and even national concern that the Corps' action might portend a change in its regulatory approach to the Clean Water Act. Navigable rivers are covered under section 404 of the CWA that ensure stricter enforcement of water quality standards.

In face of the controversy, EPA announced in August that it would consider the Santa Cruz River a "special case" and decide the designation itself. A Dec. 3 letter to the Corps from the Benjamin Grumbles, EPA assistant administrator for water, stated that the river segments should be considered "traditional navigable water" as originally posted on the Corps web site.

A navigable Santa Cruz provides environmental benefits. For example, opponents of the proposed Rosemont mine believe the designation would help restrict the controversial facility that would discharge waste into a tributary of the river. Some see the designation as the means to control development.

The river segments are located south and north of Tucson, with one segment stretching from Tubac to Continental and the other extending from Pima County's Roger Road sewage plant to the Pinal County line. Running year-round with treated sewage effluent, the river segments are bright ribbons in a mostly dry Santa Cruz.

The local issue may have turned out well, but navigability continues to be an unresolved issue at the national level. Defining navigable waters became problematic after a 2006 Supreme Court ruling muddied the navigable water concept, a decision that federal officials have been laboring ever since to incorporate into their rulemaking. The Corps' decision to review its initial Santa Cruz designation reflected this uncertain state of affairs.

Court to Determine if CWA Allows Cost-Benefit Analysis

On Dec. 2 arguments were heard in the U.S. Supreme Court challenging new Environmental Protection Agency regulations requiring power plants to retrofit water intakes to protect aquatic life. Central to the case is Section 316 of the Clean Water Act that states that the design of structures used for cooling water must "reflect the best technology available for minimizing adverse environmental impact."

In 2004, when the EPA proposed rules for existing power plants, the agency allowed operators to request a variance if the compliance cost was significantly greater than resulting environmental benefits. This was in response to an industry concern that the cost to utilities might be far in excess of any environmental gains.

Environmental groups filed suit, claiming that EPA's cost/benefit analysis violated the law by permitting structures that fail to effectively protect aquatic organisms as required by the CWA. A U.S. Court of Appeals essentially agreed, holding that cost could only be taken into account if used to enable a plant operator to apply "a less expensive technology that achieves essentially the same results."

EPA revised the rule in accordance with the decision; utility groups then petitioned the Supreme Court for review saying that the Appeal Court's finding contradicts more than 30 years of EPA's CWA interpretations. They also argued that Supreme Court precedent allows discretion to regulatory agencies to interpret the statutes.

Entergy Corp. v. EPA, 07-588 is considered a major environmental case and the decision, which is expected in the spring, will likely be an issue in the environmental debates expected with the new administration.