PA DEP Proposes Anti-degradation Policy for On-lot Septic Systems

March 2013Articles In the Zone

On February 8, 2013, the Pennsylvania Department of Environmental Protection (PA DEP) delivered a presentation to the Sewage Advisory Committee highlighting a proposed new policy addressing the use of on-lot septic systems in High Quality (HQ) and Exceptional Value (EV) watersheds.

PA Chapter 93 anti-degradation regulations provide special protection for HQ and EV watersheds as part of PA DEP’s federally-approved water quality standards program. And the draft policy is intended to address the issue of siting on-lot septic systems in these special protection watersheds primarily for new residential development.

Septic systems are considered nonpoint pollutant sources because they do not add pollutants to surface water through a pipe or similar conveyance. Chapter 93 requires that water quality in HQ and EV waters be protected and maintained. Namely, the PA DEP must “assure that cost-effective and reasonable best management practices (BMPs) for nonpoint source control are achieved.”

While septic systems are inherently protective of surface water quality when properly designed, operated and maintained, nitrates can pose potential concern in groundwater and drinking water wells.

A 2011 Environmental Hearing Board (EHB) decision, Pine Creek Watershed Assoc. v. PA DEP (EHB Docket No. 2009-168-L, Nov. 10, 2011), brought the issue to a head. In Pine Creek, PA DEP approved the use of septic systems in a small residential development in an EV watershed (Pine Creek in Berks County). The approval was appealed to the EHB on the basis that water quality in Pine Creek would not be properly maintained and protected under Chapter 93 anti-degradation requirements.

PA DEP relied primarily on a groundwater plume analysis using a model developed to design constructed wetlands to assert that nitrate would not reach the creek because the natural wetland present on the site would effectively remove the pollutant.

The EHB ruled in November 2011, that the wetland model relied upon by PA DEP was not appropriate. As such, PA DEP’s approval of the plan was rescinded.

The Pine Creek decision established a legal and scientific standard that is extremely difficult to meet, thereby jeopardizing any future development using septic systems in HQ and EV watersheds.

Through its proposed draft policy, PA DEP is attempting to implement a BMP approach for septic systems to maintain and protect water quality in HQ and EV watersheds.

Some of the BMPs outlined by the proposed draft policy include limiting on-lot system density to one-acre lot minimums; offering credit for the setback distance of the septic system from the river or stream; use of riparian buffers; use of a permeable reactive barrier; and use of denitrifying technologies with septic systems.

The proposed draft policy has not yet been published in the PA Bulletin but merely presented to the SAC for input and feedback from the advisory committee.