Language Translation
  Close Menu

Thermal Effluent Limitations

Executive Summary

A demonstration for alternative thermal effluent limitations, in accordance with Section 316(a) of the Clean Water Act [PDF] and 327 Indiana Administrative Code 5-7 (327 IAC 5-7), should provide the National Pollution Discharge and Elimination System (NPDES) permitting authority, the Indiana Department of Environmental Management (IDEM), with adequate information to establish alternative thermal effluent limitations that will ensure the protection and propagation of a balanced, indigenous community (BIC) in and on the waters into which a thermal discharge is made. The information that IDEM will need in order to authorize alternative thermal effluent limitations in a NPDES permit will be provided by the discharger through the Alternative Thermal Effluent Limitations Application and the required Type I, II, or III Demonstration. The demonstration must be conducted in accordance with IDEM’s guidance document: Guidance for Conducting a Demonstration as a Requirement of a 316(a) Alternative Thermal Effluent Limitation Request [ZIP].

This document contains the guidance necessary for completing an application for alternative thermal effluent limitations, a Type I, II, or III Demonstration, and sampling and monitoring consistent with associated standard operating procedures. The standard operating procedures provide the necessary steps for NPDES dischargers to follow for conducting comprehensive monitoring programs for temperature in a water body, conducting comprehensive monitoring programs to delineate the thermal discharge plume in the receiving water body, and conducting biological community assessments.

Demonstration Types

Type I Demonstration

A demonstration based on field studies conducted to prove the “absence of prior appreciable harm” to the BIC or BIP from a discharge. A Type I Demonstration has many of the same requirements of a Type II Demonstration but focuses on actual field studies rather than literature review to make a determination. Type I Demonstrations can be used by existing dischargers.

Type II Demonstration

A predictive demonstration based on literature, lab, and field studies conducted to assure that proposed ATEL will provide adequate protection and propagation of Representative Important Species (RIS) despite previous harm or lack of historical data and that the RIS adequately represent a BIC or BIP. Type II Demonstrations can be used by new discharger or existing dischargers applying for an ATEL.

Type III Demonstration

A demonstration that is conducted to address low potential impact discharges or when a custom study is necessary to ensure the BIC or BIP would be protected. These studies incorporate many of the features of a Type I and Type II Demonstration. Essentially, this is a term for any demonstration type agreed to by the NPDES discharger and the permitting authority that would not strictly adhere to the protocols established in this guidance for a Type I or II Demonstration.

Regulatory Framework

327 IAC 2-1-6 [PDF] and 327 IAC 2-1.5-8 [PDF] contain the water quality standards for temperature in waters outside of the Lake Michigan Basin and within the Lake Michigan Basin respectively. The water quality based effluent limitations (WQBEL) for temperature included in NPDES permits are based on the water quality standards contained in these rules. 327 IAC 5-5-2 [PDF] contains the technology standards for dischargers in waters within the State. The technology based effluent limitations (TBEL) for temperature included in NPDES permits are based upon the technology standards contained within these rules or as developed under Best Professional Judgment (BPJ) in accordance with 327 IAC 5-5-2. NPDES permits require the discharger to meet the more stringent of the WQBEL or TBEL that is applicable to the discharge.

In accordance with 327 IAC 5-7 [PDF] and Section 316(a) of the Clean Water Act [PDF], NPDES dischargers may request alternative thermal effluent limitations (ATEL) for a discharge based on a demonstration that the proposed effluent limitations for temperature are more stringent than necessary for the protection and propagation of the receiving water body’s balanced, indigenous community (BIC) or balanced indigenous population (BIP) of shellfish, fish, and wildlife in and on the body of water. 327 IAC 5-7 is based on federal regulations (40 CFR Part 125.70 through 125.73) designed to implement Section 316(a) of the Clean Water Act.

Federal Regulations

Federal regulations regarding Section 316(a) are found at 40 C.F.R. Part 125 Subpart H. The federal guidance document available to guide the approach to making a demonstration for an ATEL or for rendering a decision on the appropriateness of a requested ATEL is the Draft Interagency 316(a) Technical Guidance Manual and Guide for Thermal Effects Sections of Nuclear Facilities Environmental Impact Statements. May 1, 1977. U.S. EPA, Office of Water Enforcement, Permits Division, Industrial Permits Branch, Washington D.C. [PDF].

An additional federal guidance document which may be used to guide the approach to making a demonstration for an ATEL is the U.S. EPA. Guidelines for Ecological Risk Assessment. U.S. Environmental Protection Agency, Risk Assessment Forum, Washington, DC, EPA/630/R095/002F, 1998 [PDF].

 Top FAQs