Washington State First to Require Low Impact Stormwater Management Techniques

In the first decision of its kind in the nation, Washington’s Pollution Control Hearings Board (“Board”) recently ordered Washington state’s largest local governments to use “low-impact development” (“LID”) techniques to control stormwater “where feasible.” The order applies to the cities of Seattle and Tacoma, Clark County, King County, Pierce County, and Snohomish County, local governments encompassing western Washington’s most populous areas. It decides a challenge to the Washington Department of Ecology’s (“Ecology”) Phase I Municipal Stormwater General Permit (“Phase I Permit”).

The decision specifically addresses Phase I Permits only, but Ecology regulates stormwater discharges under several other separate general permits, including the Industrial Stormwater General Permit, the Construction Stormwater General Permit, and the Phase II Municipal permits. The Board’s reasoning for requiring LID could also apply to these other permits.

The Board’s order leaves a number of unanswered questions, including when the LID requirements will take effect, how they will apply to individual sites and projects, how Ecology will define and apply the “where feasible” standard, and who will determine whether a permittee has met the LID requirement. If the Board’s order stands, it may require local governments to revise their building and land use codes. In the meantime, the decision creates a fair amount of uncertainty for Western Washington local governments and developers trying to navigate between the Board’s requirement to use LID for stormwater management and the as yet unanswered questions that continue to limit the scope of applying such techniques.

LID and Stormwater

Most stormwater runoff collected in municipal separate storm sewers and discharged to surface waters is now required to have a permit under the federal Clean Water Act (“CWA”). [1] In the 1990s, the Environmental Protection Agency (“EPA”) enacted stormwater regulations that established a two phase (Phase I and Phase II) municipal stormwater permit program. Ecology is delegated the authority by EPA to implement the CWA and permit municipal stormwater discharges in Washington state and by the State under the Washington Pollution Control Act (“WPCA”)[2] and Ecology’s Water Quality Regulations.[3] Those regulations make it illegal to discharge pollutants to “waters of the State” without a permit. EPA has identified stormwater discharges as a major source of pollution for all waterbody types in the United States[4] and Ecology has in turn identified stormwater runoff as the state’s largest source of urban water pollution.[5]

LID utilizes design techniques that allow stormwater to infiltrate close to its source to mimic the way water moved through the landscape before it was developed. Traditional approaches to stormwater management typically involve hard infrastructure, such as curbs, gutters, and piping. LID-based designs, in contrast, comprise a set of site design approaches and small-scale stormwater management practices that use natural drainage features or engineered swales and vegetated contours to infiltrate, convey, and treat stormwater runoff.[6] EPA touts these practices as effective means of removing nutrients, pathogens, and metals from stormwater, and reducing the volume and intensity of stormwater flows.[7]

Municipal Stormwater Permits in Washington

Effective February 16, 2007, Ecology revised its existing Phase I Municipal Stormwater General Permit. At the same time, Ecology issued new Phase II Municipal Stormwater General Permits impacting 100 cities, 13 counties, and other entities and, for the first time, requiring them to regulate discharges from their stormwater systems. The new Phase I and II Municipal Stormwater permits require municipalities and other public entities to adopt ordinances or otherwise develop and implement stormwater management systems that include, at minimum: public education and outreach; public participation; illicit discharge detection and elimination; stormwater runoff control from new development, redevelopment, and construction sites; and pollution prevention.[8]

Environmental groups appealed the new Phase I and II permits, arguing that they are not sufficiently protective of the environment.[9] Cities, counties, and other Phase I and II permittees also appealed the permits, contending that they are overly protective and unduly burdensome.[10] The Phase II suit is still partially pending before the Board. The Board’s decision on the Phase I suit does, however, provide guidance on how the Board may decide the Phase II suit. For more on Ecology’s Phase I and II Permits see Washington State Issues New Stormwater Permit Rules Affecting 100 Cities, 13 Counties, Marten Law Group Environmental News (February 21, 2007).

The Board’s Decision

The environmental group’s major argument against the Phase I Permit was their contention that traditional structural engineered stormwater management practices are inadequate to address municipal stormwater and that Ecology should have also required the Phase I permittees to use LID practices on a broader and more comprehensive scale.[11] In the Phase I Permit, Ecology chose to regulate the rate at which stormwater is released from management systems.

Ecology staff who developed the Phase I permit, as well as a number of stormwater experts who testified before the Board, agreed in part with the environmental appellants and concluded that “a combination of aggressive use of LID techniques, best conventional engineering techniques to manage high flows … and land use actions to preserve a high percentage of native land cover, are necessary to reduce pollutants in stormwater to the maximum extent, and to preserve water quality.”[12]

The Board concluded that the Permit must require municipalities to employ broader use of LID at the parcel and subdivision level.[13] The Board stopped short, however, of concluding that the Permit must, at this time, require use of LID at the basin and watershed level.[14] The Board held that the Permit is generally valid but partially modified the Permit to require, rather than simply allow, LID “where feasible.”[15]

The Board also addressed whether requiring increased LID under the Phase I Permit would conflict with Washington’s Growth Management Act (“GMA”)[16] or Shoreline Management Act (“SMA”)[17] or usurp local government’s land use regulatory authority under either Act.[18] The Board concluded that Ecology may require use of LID as a water quality management tool without conflicting with or violating the GMA or SMA.[19]

The City of Seattle is similarly revising its Stormwater Code to require all single-family residential development projects and certain other development projects to implement “green infrastructure technologies” for stormwater control.[20] Such technologies include porous pavement, green roofs, and cisterns. Seattle is one of the first cities in the country to require LID technologies which incorporate green infrastructure. For more on Seattle’s Code revisions see J. Kray, A Perfect Storm(water), Marten Law Group Environmental News (March 19, 2008).

The Board’s decision goes beyond the EPA’s or Ecology’s stormwater rules or permits, which have encouraged but do not require the use of LID and may require developers to comply with other laws in order to fully utilize or apply LID techniques.[21] For example, for one LID technique – rainwater harvesting – Washington has a de facto exemption from its water laws but requires a permit to harvest any more than modest water amounts. Ecology has, therefore, proposed but not yet enacted a rule that clarifies its historical permit exception for capturing, storing, and using small rainwater amounts. The proposed rule would also create a process for permitting larger rainwater harvesting projects, and define the threshold at which such permits are required. For more on rainwater harvesting see J. Kray, A Box of Rain – States Take a Closer Look at Rainwater Harvesting, Marten Law Group Environmental News (July 23, 2008).

Local governments may need to revise their codes to permit LID techniques. As the Board acknowledged, “[t]o fully incorporate LID principles into this system will require [local governments to] review, consider, and in some instances modify, … existing zoning and building regulations that create obstacles to the use of LID.”[22] For example, local government codes and ordinances related to road width, curbs and gutters, vegetation clearing, and parking spaces may make it difficult to utilize certain LID techniques.[23]

Finally, the Board’s Order leaves much up to Ecology. Concluding that portions of the Phase I Permit are invalid, the Board remanded it to Ecology to modify the Permit and require LID consistent with the Order and “where feasible.” Ecology will, however, have substantial discretion to determine where LID is feasible and the scientific, economic, and practical standards against which to measure feasibility. Until Ecology completes that process, parties responsible for or governed by the Phase I permit will not have the certainty they need about the extent to which LID is required for development and redevelopment projects.

Conclusion

None of the parties have indicated whether they plan to appeal the Board’s decision. The appeal deadline will run on September 8, 2008. If the Board’s decision stands, larger local governments in Western Washington will now have to incorporate LID techniques into their planning and codes. For developers, municipalities, regulators, and others outside Washington, the decision is worth noting as it suggests a trend toward requiring wider use of methods that allow stormwater to percolate into the ground rather than run through a pipe into streams, rivers, and larger water bodies such as Puget Sound.

For more information on stormwater management and Marten Law Group’s water quality and water resources practices please contact Jeff Kray.