Regulating Water Intake Structures

Implementing Section 316(b) of the Clean Water Act & s. 283.31(6), Wis. Stats.

Section 316(b) of the federal Clean Water Act requires, and Section 283.31(6), Wisconsin Statutes, allows the Department to require that the location, design, construction, and capacity of intake structures reflect the best technology available (BTA) for minimizing adverse environmental impact. The Department's authority to regulate intake structures is tied to the issuance of Wisconsin Pollutant Discharge Elimination System (WPDES) permits and is found in s. 283.31(6), Wis. Stats:

“Any permit issued by the department under this chapter which by its terms limits the discharge of one or more pollutants into the waters of the state may require that the location, design, construction and capacity of water intake structures reflect the best technology available for minimizing adverse environmental impact.”

For many years, federal 316(b) regulations have been implemented without specific standards in place, on a resource-intensive, site-by-site basis. Following settlement of a lawsuit in the mid-1990’s, USEPA began developing national standards in three phases for regulating Cooling Water Intake Structures (CWIS): Phase I for new facilities, Phase II for existing power plants, and Phase III for new offshore oil and gas extraction facilities.

For more information on EPA's Phase I-III rules, go to: EPAPhases.htm

WDNR Guidance for Evaluating Cooling Water Intake Structures (February 2005). Additional guidance is provided here which describes the 3 Phases of USEPA's 316(b) rules. This document provides WDNR staff guidance regarding the information needed to evaluate the potential impacts of a cooling water intake structure (CWIS) and to determine whether BTA is being used (or proposed) to minimize adverse environmental impacts.

Intake Structures Not Addressed in 316(b) - The Need for BPJ

The federal rules described above spell out 316(b) requirements for new facilities (Phase I), large, existing power plants (Phase II), and offshore oil and gas extraction facilities (Phase III). However, there are a number of facilities that are not specifically addressed by these rules, including:

USEPA did not include uniform national standards for non-Phase II existing facilities. Instead, they said they “will continue to rely on [the NPDES] program, which implements section 316(b) for these facilities on a case-by-case, best professional judgment (BPJ) basis.” USEPA has emphasized that all facilities, including those not specifically addressed in the rules, must be evaluated for 316(b) compliance. For those facilities not addressed in Phase I, II, or III rules, states are required to make a BTA determination using BPJ.

Additional guidance was needed to address BPJ decision-making, because of challenges which have resulted in the suspension of some parts of the 316(b) regulations and the application of BTA to other (non-Phase I, II & III) facilities with intake structures. The following guidance was written in an attempt to clarify what WDNR staff need to do when reissuing a permit to a facility that has an existing surface water intake structure, but that does not fall under the federal Phase I-III 316(b) regulations.

Guidance for Evaluating Intake Structures Using Best Professional Judgment (BPJ) [PDF 87KB]

If you have any questions regarding the WDNR's intake structure guidance or this website, please email Kari Fleming.