On Nov. 14, the Water Environment Federation (WEF) filed comments on the U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers’ (Corps) Waters of the United States proposed rule. WEF supports EPA’s intent in protecting the nation’s waters while providing input on how the proposed rule may be clarified. WEF comments focus on key definitions important to utilities as well as recommendations for improving exemptions meaningful to municipalities. WEF worked with a number of its member associations and compiled an extensive set of targeted comments. Here are some of WEF’s comments as they relate to stormwater and watersheds.

The proposed rule does not change the existing regulatory language regarding the explicit exclusion of waste treatment systems designed to meet Clean Water Act requirements. However, WEF states that the exemption should specifically include municipal separate storm sewer system infrastructure and stormwater runoff controls, and there is widely held agreement in the sector on this point.

EPA and the Corps do not intend for traditional stormwater practices or green infrastructure facilities to be considered jurisdictional Waters of the U.S., but the lack of language explicitly outlining the exclusion of these systems leaves the rule open for interpretation. To clarify that waters associated with stormwater infrastructure are not considered Waters of the U.S., WEF suggests that specific terms, such as “stormwater control measures” or “best management practices,” be integrated into the regulations and clearly exempted. The rule also should further define the systems to which the exemption applies and could include man-made structures and devices as well as treatment measures used to improve water quality, reduce stormwater volume, control flow rate and flooding, convey stormwater, or any combination of these purposes.

For the first time, the proposed rule seeks to define what constitutes a “tributary” under the Clean Water Act. The proposed rule potentially expands the number of waters subject to federal jurisdiction. Specifically, the proposed rule defines ‘‘tributary’’ as a water “physically characterized by the presence of a bed and banks and ordinary high water mark…which contributes flow, either directly or through another water…” to a water of the U.S. This definition of tributary could potentially increase the number of man-made ditches and conveyance facilities considered waters of the U.S. WEF calls for further clarification on the definition of a tributary, particularly as it applies to green infrastructure. While green infrastructure is not mentioned in the proposed rule, the tributary definition and its potential impacts on ditches could inadvertently affect green infrastructure adoption.

As the proposed rule relates to stormwater and wet weather issues, WEF asks how EPA intends to establish applicable, defensible water quality standards and monitoring requirements at claimed pollutant sources, such as ephemeral stream areas under short-term wet weather conveyance conditions.

The proposed rule also mentions that certain stormwater conveyance facilities, previously considered nonpoint sources, could be considered point sources. This would imply that some total maximum daily load determinations involving both point source waste load allocations and nonpoint source load allocations may have to be reexamined and reissued as a result of the proposed rule. WEF suggests that connectivity factors separately distinguish short-term wet weather impacts from long-term effects. The EPA also should describe how established water quality standards are to be addressed in a meaningful, defensible manner at the pollutant source.

For more on Waters of the U.S. as it relates to stormwater, read the November feature on “Defining Waters of the U.S. and the Effects on Stormwater,” and view the recording of the WEF webinar “Viewpoints: Potential Impacts of Waters of the U.S. Rulemaking on Stormwater Infrastructure.” Also check out a report on the proposed rule by the Local Government Advisory Committee’s Protecting America’s Waters Workgroup.