Our Insights

The Shape of Water Law

May 6, 2020

Emily J. Dupraz and William E. Taylor │ Pierce Atwood, LLP

This article was originally published in Currents, POWER’s quarterly Environmental newsletter.

There have been several recent and significant legal changes to the Clean Water Act (CWA), its implementing rules and the manner in which the law has been previously administered that environmental professionals should review.

First, the definition of “waters of the United States” (WOTUS) has been narrowed. Other significant changes include: a revision to the 401 water quality certification regulation; a Supreme Court decision that determined that the release of pollutants to groundwater could be subject to the CWA’s permitting scheme; and new interpretations of temperature total maximum daily load (TMDL) regulations.

Waters of the United States

In January 2020, the U.S. Environmental Protection Agency (EPA) issued a final rule revising the definition of WOTUS. The rule narrows the definition by excluding ephemeral waterbodies and wetlands that are not adjacent to other jurisdictional waters. The rule is likely to affect mining, construction, agriculture and aggregate industries. Publication of the rule followed a series of lawsuits challenging the prior rule.

It is anticipated that the definitional change will have the most impact in western states where water flow is not continuous year-round. Opponents of the new rule have argued that it would reduce jurisdiction over thousands of miles of streambeds and millions of acres of wetlands. However, it is unlikely to have that great of an effect because many states have adopted or may adopt rules that are more protective.

401 Water Quality Certification Regulations

On August 8, 2019, EPA issued a proposed rule relating to Section 401 of the CWA. CWA Section 401 requires that applicants seeking a federal license or permit that may result in a discharge into WOTUS also obtain a state certification that the discharge complies with state water quality standards. Existing water quality certification regulations had not been updated in nearly 50 years.

Key proposed changes are: establishing one year as the statutory reasonable period of time for certifying authorities to act on a certification request, clarifying that the start of the statutory timeline for certification review begins upon receipt by the certifying authority of a “certification request” and requiring that supporting information be provided for each condition imposed by the State (e.g., a statement explaining why the condition is necessary).

Federal Regulation of Discharges to Groundwater

The Supreme Court recently held, for the first time, that discharges into groundwater which ultimately convey into a navigable water, could be governed by the CWA’s permitting requirements. Relying on CWA’s statutory purpose of protecting the nation’s waterways, the Supreme Court held that a CWA permit is required for a direct discharge—or its “functional equivalent”—of pollutants into a navigable water.

The Supreme Court’s decision settles a disagreement between the federal courts and the EPA. The Fourth and Ninth Circuits held that discharges into groundwater could be governed by the CWA.

In April 2019, EPA took a contrary position and issued an interpretive statement clarifying that releases of pollutants to groundwater are categorically excluded from the CWA’s permitting requirements, regardless of whether that groundwater is hydrologically connected to surface water. The Supreme Court’s expansion of CWA jurisdiction will have major impacts in many states where discharges to groundwater were not previously regulated.

TMDL Regulations

The Ninth Circuit recently held that EPA has a non-discretionary duty to issue a temperature TMDL for the Columbia and Snake Rivers because the states of Washington and Oregon had failed to do so. The Columbia and Snake Rivers are habitats for several species of salmon and trout, which require cold water temperatures for their survival. Over the years, the water temperatures in the rivers have increased due to dams and point-source discharges, which is significant given that EPA considers “heat” to be a pollutant for issuing TMDLs. Though the extent of its impact is still underdetermined, this decision sets a precedent by which EPA might be required to establish TMDLs for other pollutants where states have failed to act.


While there will always be shifts in policy or regulatory emphasis resulting from new pollutants (i.e., PFAS), new environmental conditions (i.e., ocean acidification) or administrative needs (i.e., water quality trading and integrated planning), the changes summarized above are fundamental, structural changes to the CWA that alter long-standing interpretations of both law and rule.

As such, environmental professionals should take note of these changes and reevaluate their expert advice in light of these new legal interpretations.

About the Authors:

Emily Dupraz provides counsel on environmental and land use matters including permitting, compliance, enforcement, and litigation support.  Her broad environmental practice spans the Clean Air Act, Clean Water Act, CERCLA, EPCRA, and their state equivalents, as well as other statutes and rules related to endangered species, natural resources, hazardous and solid waste, and local zoning.



Since joining Pierce Atwood’s Environmental Group in 1984, William “Bill” Taylor has devoted his legal practice to matters related to water law, waste discharge, stormwater and natural resource licensing, compliance counseling, rulemaking, auditing and enforcement. He regularly represents clients before local, state, and federal administrative agencies.