Municipalities Face Specter of New TMDL Rules
By L. Scott Tucker
A significant issue facing municipalities today is the specter of new stormwater end-of-pipe numerical effluent requirements that could be issued by the US Environmental Protection Agency (EPA) and states. EPA is not recommending this action now; however the potential exists and the municipal community remains threatened.
Environmental groups have filed lawsuits to require numerical limits for stormwater, but thus far have failed. This legal assault will probably continue. EPA adopted an interim policy in 1996 that recommends that numerical end-of-pipe limits not be used for stormwater, but the interim nature of the policy makes it just that - interim. An ominous sign, however, is a recent EPA decision to impose numerical effluent limits on a municipal stormwater discharge for Hickey Run in the Washington, D.C., stormwater system.
The Phase I stormwater permitting program for cities over 100,000 has been in effect for several years, and rules were recently promulgated by EPA for Phase II to require all cities and counties in urban areas with populations of more than 50,000 to obtain stormwater permits. Local governments must implement best management practices in order to comply with permit conditions. This can be an expensive unfunded mandate, but local governments at least retain control over the way(s) in which they meet permit conditions. If the rules of the game change, and cities and counties are held to end-of-pipe numeric effluent limits, it will become extremely difficult, if not impossible, to meet the standards. A city cannot have absolute control over the substances that wash off many square miles of cityscape.
Logically, it is difficult to understand why the EPA defines municipal stormwater as a point source of pollution. Rainwater falling on cities and flowing through the local storm drainage system, streams, rivers and lakes creates a diffused or non-point pollution problem that differs fundamentally from point sources of discharge such as public sewage treatment plants. The usual way of permitting point sources is to assign maximum pollutant limits that can be discharged into receiving waters at the end of the discharger's pipe. A large metropolitan area may have thousands of stormwater discharge points. It is impossible for the municipality to know and control the quality of stormwater discharged from every pipe and ditch that flows into streams and lakes. Cities can take steps to mitigate impacts of stormwater runoff, but it will be impossible to eliminate those impacts.
Basically, TMDLs allocate pollutant loads to various pollutant dischargers where water bodies currently are not meeting water quality standards. National Pollutant Discharge Elimination System (NPDES) permits will be used to define and allocate, through an enforceable mechanism, the pollutant load limitation for point sources. Since municipal stormwater is defined as a point source of pollution, local governments are concerned that end-of-pipe limits may be used to regulate and control stormwater systems. This fear has intensified by the recent EPA decision to include a numeric limit for oil and grease discharges of 11.9 lbs. per day for Hickey Run, a tributary of the Anacostia River in Washington, D.C.
The TMDL regulation that EPA recently proposed fails to recognize Congress' original intent to address municipal stormwater differently than traditional point sources. The Clean Water Act requires the reduction of pollutants in municipal stormwater to the maximum extent practicable. The law does not require numeric effluent limitations for stormwater, an issue recently upheld in stormwater litigation in the Ninth Circuit Court of Appeals in the case of the Defenders of Wildlife and The Sierra Club vs. EPA, Case No. 98-71080.
The National Association of Flood and Stormwater Management Agencies (NAFSMA) recently appeared before the House Water Resources and Environment Subcommittee at a hearing on TMDLs. NAFSMA and other organizations such as the National League of Cities (NLC) raised several issues regarding the EPA proposed regulation. One troublesome provision, appearing in proposed changes to NPDES permit regulations that will accompany new TMDL planning regulations, would require new dischargers to waterbodies where a TMDL is required, or existing dischargers that propose to increase their discharges by 20 percent, to provide a 1.5 to 1 offset for these increased loadings.
The offset would require a discharger to find another discharger on the stream to reduce its loading, which would create a trading arrangement. The proposed offset requirement would impose an arbitrary and substantial burden on new and existing dischargers. Applying this concept to municipal stormwater discharges would be difficult if not impossible to achieve. This issue raised so much concern that EPA wrote to the Senate Environment and Public Works Committee and the House Committee on Transportation and Infrastructure that they may drop the offset requirement. Other concerns were raised and EPA suggested they may address some of them in the final rule as well.
The fundamental problem with the TMDL concept will remain, however, because of the continual references to wasteload allocations for stormwater discharges under the TMDL proposal. The EPA claims that it is unreasonable to apply numerical limits to stormwater while it is implementing a TMDL process based on wasteload allocations. NAFSMA and NLC commented before the House Water Resources Subcommittee that there is inadequate knowledge, inexact technology, insufficient resources, and other insurmountable barriers to reasonably assume numerical limits can be met for municipal stormwater systems under any circumstances.
It must be recognized that EPA will keep moving the standards once the regulated community begins consistently to meet the prevailing requirements. The target will keep getting harder and more expensive to achieve. A basic question is "How much is the public willing to pay to achieve the goal of no discharge of pollutants into the nation's waters?"
The public wants clean water. Environmental groups want strict regulations, to control growth and eliminate all pollution sources. Industry wants to minimize costs because of competitive pressures. State and local governments are responsible for getting the job done - which means striking a balance. Local governments want clean water because their citizens want clean water, but they have limited resources and have other responsibilities such as public safety, transportation, fire protection, etc. that they must address.
So where does this leave the municipal community? TMDL remains the next step that will be used to reach closer to the impossible goal of eliminating pollutant discharges. Municipalities will continue to head in that direction until the public believes the waters are "clean enough" and they do not want to pay any more taxes. Clearly, the regulatory climate is evolving from a perspective of environmental protection to environmental perfection.
Author's note
L. Scott Tucker is the Executive Director of the Urban Drainage and Flood Control District, a multi-jurisdictional, special purpose district that addresses drainage and flood control issues in the Denver metropolitan area.