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States May Set Thermal Effluent Standards Stricter Than Federal Clean Water Act Standards

February 11, 2010

The Vermont Supreme Court recently affirmed issuance of a variance allowing the Vermont Yankee Nuclear Power Station to increase the temperature of its summer cooling water discharges. The Supreme Court agreed with the environmental plaintiffs in In re Entergy Nuclear Vermont Yankee Discharge Permit[1] that states may set thermal effluent standards stricter than the federal CWA standards contained in Clean Water Act (CWA) Section 316(a),[2] but upheld a variance issued by the state of Vermont from the stricter state thermal effluent requirements.

Entergy’s Thermal Effluent

Entergy operates the Vermont Yankee Nuclear Power Station, a boiling water nuclear reactor located on the Connecticut River in Vernon, Vermont. Nuclear and fossil-fuel plants generate electricity by heating purified water to create steam. The steam is used to drive turbines, which in turn drive the generators that produce electricity. Steam that has passed through the turbines must be condensed, requiring Entergy to remove heat and cool the station. The Vermont Yankee facility utilizes a cooling water system in which water drawn from the Connecticut River flows to the plant and removes heat as it travels through the condenser. Such a facility can discharge heated water in one of two ways: (1) through closed cycle cooling, in which the heated cooling water is circulated in cooling towers and mechanically cooled or; (2) through a “once through” open cycle cooling, in which the heated cooling water is discharged into the river where it mixes with the river water and dissipates. Water discharged from the plant is warmer than the water taken in, and the temperature difference may be large enough to affect aquatic life. Such thermal discharges are regulated under the federal Clean Water Act (CWA). [3]

The Entergy Variance and American Shad

In 2003, ANR issued an amended National Pollution Discharge Elimination System (NPDES) discharge permit allowing Entergy to bypass Vermont Yankee’s cooling towers, increase its thermal discharge, and raise the temperature of a portion of the Connecticut River known as the “Vernon Pool” by 1ºF between June 16 and October 14 each year. The period of the temperature increase ANR granted Entergy overlaps with the spawning season for the American shad, an anadromous species of fish native to the Connecticut River and the focus of a major recovery effort. Adult shad spawn in the Connecticut between April and July. Juvenile shad remain in the river until August or September before beginning their journey to the Atlantic Ocean. River temperature has a bearing on both spawning and rearing success, which in turn determines the productivity and viability of the shad population in the Connecticut River. The reach of the Connecticut River affected by this discharge is designated as a “coldwater fishery” under Vermont Water Quality Standards (VWQS). These standards specify that “[t]he total increase from the ambient temperature due to all discharges and activities shall not exceed 1ºF.”[4]

Procedural History

Plaintiff Watershed Council appealed the Vermont Environmental Court's decision granting in part and denying in part Entergy Nuclear Vermont Yankee's (Entergy) request for a permit amendment under the CWA. Entergy and ANR cross-appealed the Environmental Court’s decision to impose monitoring and additional temperature conditions on the amended permit. The Vermont Supreme Court affirmed ANR’s decision to grant Entergy a variance but reversed the additional conditions the Environmental Court sought to impose on Entergy.

CWA Section 316(a)

Thermal pollution occurs when any process increases or decreases ambient water temperature sufficiently to harm fish, plants, or other aquatic organisms. Under the CWA, thermal effluent – such as cooling water discharged during open cycle cooling – is a pollutant, and facilities wishing to discharge thermal effluent into a water source must apply for a NPDES permit.[5] The CWA’s statutory scheme embraces a cooperative federalism approach to environmental regulation and carves out a joint role for federal and state oversight and enforcement.[6]

CWA Section 316(a) allows a thermal discharger to obtain a thermal effluent variance by demonstrating that less stringent thermal effluent limitations would still protect aquatic life.[7] A substantial portion of U.S. steam electric generating capacity operates under Section 316(a) variances.

To receive a Section 316(a) variance, a discharger must demonstrate to the appropriate regulatory agency that alternative thermal limits will not cause significant harm to the aquatic life in the receiving waters. The effort required to make this case varies greatly, depending on state requirements and the site-specific potential for impacts. In nearly all cases, however, the demonstration involves extensive evaluation of potential impacts and characterization of local aquatic populations. A regulatory agency can reject a demonstration or ask the discharger to study certain issues in more detail.

CWA Section 316 sets forth specific criteria used to evaluate the discharge of heat (as opposed to other pollutants) in the NPDES permit context.[8] Under this section, a permit applicant may apply for a variance from otherwise applicable thermal discharge limitations if the applicant can demonstrate that it will nonetheless “assure the protection and propagation of a balanced, indigenous population of shellfish, fish, and wildlife.[9] EPA refers to this standard as “BIP.” The “BIP” standard is generally more flexible than the numeric temperature criterion for a waterway.

It is this type of thermal variance request that was the subject of the permit amendment before the Vermont Supreme Court. Section 316(a) demonstrations are comprehensive studies which include evaluation of historical data and predictive impact modeling. The review and evaluation of these demonstrations is coordinated by the appropriate state regulatory agency, the U.S. Fish and Wildlife Service, and any interested basin compacts or interstate basin commissions. A successful 316(a) demonstration results in alternative thermal effluent limitations for a specific discharger, but does not change the water quality standards for the receiving water body.

The Entergy Decision

The Watershed Council contended that, among other arguments, the Environmental Court erred in failing to: “analyze the appropriate ‘body of water’; require the necessary demonstration under § 316(a); consider ‘cumulative effects’ of the discharge; require Entergy to demonstrate that prior discharges have not caused ‘prior appreciable harm’ to the ecosystem; and consider appropriate representative important species.”[10] The Court held that “[g]iven the statutory and regulatory language set forth in the CWA, the applicable body of water is only that which is affected by Entergy's thermal plume.”[11] The Court further held that the Environmental Court properly considered Entergy’s “entire history,” took into account the cumulative effects of Entergy’s discharge when affirming the permit amendment, and that its conclusion Entergy met the BIP standard was supported by the evidence.[12] The Supreme Court also found that the Environmental Court’s conclusion that there was no evidence that Entergy’s thermal effluent discharges prior to the permit amendment was not clearly erroneous. Finally, the Court rejected the Watershed Council’s arguments that the Environmental Court failed to consider additional cold water species of fish, such as brook trout, brown trout, and rainbow trout, among the nine “representative important species” (RIS) Entergy identified in its 2004 Section 316(a) demonstration project performed in support of the variance application. As to this latter issue, the Court found the Watershed Council’s experts’ arguments that the RIS favored warm water species at the expense of more sensitive cold water species to be without merit.

The Watershed Council also argued that “the Environmental Court was required to apply the Vermont Water Quality Standards (VWQS) to the proposed permit amendment, and that it failed to do so.” The Supreme Court agreed with the Watershed Council that the VWQS are applicable to a thermal variance application, but concluded that the Environmental Court correctly applied these standards to Entergy’s variance. On this point, the Court held that “Federal requirements for the content of state water quality standards represent a floor; state standards may, therefore, be stricter.”[13] The Court did not interpret the CWA’s thermal discharge variance provisions “as completely obliterating the standards set forth in the VWQS.” Because federal regulations promulgated under the CWA[14] make explicit reference to the applicable state thermal effluent standards and thus incorporate those standards into the variance analysis, the Court held that the VWQS standards apply to Entergy’s variance application.[15]

The Vermont Supreme Court’s holding stands for the proposition that state water quality standards apply even under a Section 316(a) thermal variance process. States may impose thermal effluent requirements stricter than would be required under the federal CWA Section 316(a) standard alone.[16] In this case, however, the court held that states may also waive those requirements, and held that Vermont had properly done so.

For more information on water quality issues, please contact Jeff Kray or any other member of Marten Law’s Water Quality practice group.

[1] ___ A.2d ___, 2009 WL 4878507 (Vt.), 2009 VT 124.

[2] Id.

[3] Id.

[4] Id..

[5] 33 U.S.C. § 1342; see also 40 C.F.R. § 122.2 (defining pollutant as including “heat”).

[6] See 33 U.S.C. § 1251(b).

[7] ___ A.2d ___, 2009 WL 4878507 (Vt.), 2009 VT 124.

[8] 33 U.S.C. § 1326.

[9] 33 U.S.C. § 1326(a); 40 C.F.R. § 125.71(c).

[10] ___ A.2d ___, 2009 WL 4878507 (Vt.), 2009 VT 124.

[11] Id.

[12] Id.

[13] Id., citing 33 U.S.C § 1370; 40 C.F.R. § 131.4(a); see also In re Town of Sherburne, 154 Vt. 596, 601 n. 6, 581 A.2d 274, 277 n. 6 (1990) (noting that “[b]ecause state regulations may impose more rigorous standards than the federal counterparts, state agencies should first look to the state regulations for guidance”); Natural Res. Def. Council, Inc. v. EPA, 859 F.2d 156, 174 (D.C.Cir.1988) (noting that “[i]n fashioning its guidelines … EPA endeavored to reconcile the competing objectives of regulatory uniformity and state autonomy by establishing a floor for … state enforcement authority, while ensuring that states have the maximum possible independence”).

[14] 33 U.S.C. § 1326(a).

[15] ___ A.2d ___, 2009 WL 4878507 (Vt.), 2009 VT 124.

[16] Id.

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