The Library

Small Municipal Separate Storm Sewer System Controls Get Tightened Another Notch

This article was originally published in the June 2009 edition of the Chester County Bar Association's monthly newsletter "New Matter."

On April 4, 2009, the Pennsylvania Department of Environmental Protection (“PaDEP”) issued a request for comment on revisions to PAG-13 (39 Pa.B. 1749). PAG-13 is the National Pollution Discharge Elimination System (“NPDES”) general permit for stormwater discharges from small Municipal Separate Storm Sewer Systems (“MS4s”), and the permit authorizes the discharge of stormwater from the pipes and conveyances of municipalities. The deadline for comments is July 6, 2009.

This action is part of the process by which the regulatory agencies are gradually tightening control over the discharge of storm water from municipal stormwater pipes and conveyances, to the waters of the Commonwealth. Many Chester County municipalities (e.g., Tredyffrin Township, West Chester Borough, etc.) own and manage storm water discharge systems that serve various portions of their communities.

These systems, in most cases, collect rainwater runoff and then convey and discharge the flows to the rivers and streams of the Commonwealth.

However, inadequately managed stormwater carries all manner of pollutants (pesticides, fertilizers, oils, gasoline, etc.) from the land surface into streams, rivers, ponds and lakes, and is a cause of stream bank erosion, stream bank scouring, sedimentation, habitat destruction, water pollution and water quality degradation. In addition, when stormwater is conveyed away from land, it is no longer available for infiltration into the local aquifers, thus leaving inadequate groundwater supplies for use as stream base flow during times of drought.

Thus far, the agencies have not required that conventional water treatment controls be implemented to clean these flows prior to discharge, but many environmental lawyers think this is coming, given the difficulties the agencies have experienced in trying to achieve the federal Clean Water Act goals for “fishable, swimmable” streams and rivers.

Instead of conventional water treatment controls (like settling basins, aeration basins and chemical addition), the PAG-13 uses “narrative” (as opposed to “numerical”) standards, and requires municipalities to design a stormwater management program comprised of six minimum control measures (e.g., public education, public participation, post-construction runoff controls, etc.).

In order to provide the legal mechanisms to control stormwater discharges, PAG-13 requires that the municipality adopt the model municipal storm water ordinance (or an equivalent ordinance enacted under the authority of the Pa Stormwater Management Act). This model ordinance is available on the Department’s website. PAG-13 provides that if the model ordinance is not adopted, then the municipality may not use PAG-13, and must apply for an individual NPDES permit (often a much more difficult and time consuming process).

The revised PAG-13 proposes some interesting changes, particularly in areas where the receiving streams will be subject to TMDLs (“total maximum daily load”) limits. The TMDL program is implemented when receiving streams need additional discharge controls in order to reduce incoming pollution from point sources (of which MS4s are one source).

The revised PAG-13 requires municipalities to implement two additional control measures (such as, disconnection of impervious areas, construction of infiltration/recharge facilities, tree planting, stormwater basin retrofitting, restoration of stream banks, establishment of new stream buffers, and installation of  green infrastructure), and to obtain pollutant reductions consistent with the TMDL.

This latter requirement likely is the rub. We think that the control measures, in many cases, will not achieve the pollution reductions “consistent” (whatever that means) with the TMDL requirements. In this event, we think the agencies will require additional “numeric” measures in the next permit round. How this will be funded is anybody’s guess.

For more information, please contact John R. Embick at 215.829.9900 or jembick@thorpreed.com.

This Thorp Reed & Armstrong, LLP article is prepared in summary form and is not to be construed as legal advice or opinion on any specific fact or circumstance. We do not assume any responsibility to revise the Communiqué if there are subsequent changes in the law.

June 2009