Massachusetts Thermal Discharges regulations & environmental compliance analysis

Massachusetts Thermal Discharges: What you need to know

Governing Law and Regulations

Water quality standards and limitations: 314 Code of Massachusetts Regulations (CMR) 3.11 and 314 CMR 4.03 to 4.06

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Thermal limitations: 314 CMR 4.05 to 4.06

Effluent limitations and variances in permits: 314 CMR 3.10 to 3.11

Water classification: 314 CMR 4.05 (3)

Regulatory Agencies

Massachusetts Department of Environmental Protection (DEP) Bureau of Resource Protection

DEP Bureau of Waste Prevention

U.S. Environmental Protection Agency (EPA) Region 1

See ADDRESSES & CONTACTS for addresses and telephone numbers.

See national section for basic information and federal regulations.

Comparison: State vs. Federal

Rules. Massachusetts has established specific guidelines for thermal discharges into its waters, according to a general state water classification scheme. The Commonwealth's regulations generally follow the federal Clean Water Act (CWA). See the national section THERMAL DISCHARGES for more information about the federal requirements under the CWA.

Administration and enforcement. EPA and DEP share responsibility for the administration and enforcement of the state's thermal discharge regulations.

State Requirements


314 CMR 4.05 to 4.06

For the purpose of applying surface water quality standards in Massachusetts, all state waters are listed and classified. The temperature of the classified state waters may not exceed certain levels, and the rise in the water temperature is limited as described in the Table in this section.

In addition, natural seasonal and daily temperature variations have to be maintained in all classified waters. There cannot be any temperature changes that would impair the use assigned to these classified waters, including site-specific ...

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