Christine Troxell of Barry Isett Engineers opened Allen Township’s Board of Supervisors meeting July 10 with a briefing on the township’s proposed MS4 plan.

The MS4 plan is a requirement from the state to control stormwater discharge. The township is in the last year of its five-year National Pollutant Discharge Elimination System (NPDES) permit, and the permit is up for renewal. The Environmental Protection Agency delegated the authority to issue NPDES permits in Pennsylvania to the state Department of Environmental Protection (DEP). MS4 is a plan to reduce stormwater pollution and is a subset of the NPDES permit.

The goal of the new program is to reduce sedimentation by 10 percent and reduce phosphorus by 5 percent. Sediment is said to clog waterways and is usually in runoff from hard surfaces like roadways. Too much phosphorus in the water can disrupt the ecology of a stream and is usually in runoff from stream banks.

Allen Township has four waterways designated by the DEP as impaired. Impaired means they are below Class A standards. The waterway focuses of the MS4 application are the Lehigh River and the Hokendauqua, Dry Run and Catasauqua creeks.

To meet the permit requirements, Barry Isett Engineers developed a list of Best Management Practices (BMPs) to achieve the goals. Most of the projects are in place and need improvements to achieve the goals of the program.

The Lehigh River is measured as having 51,000 pounds of sediment and 74 pounds of phosphorus per year. To meet the new requirements, a rain garden is proposed along Eisenhower Drive. An alternate is to put a rain garden along the towpath.

Hokendauqua Creek measures in at 475,000 pounds of sediment. Phosphorus is not a measurable problem. The proposal to reduce sedimentation includes improvements to the bioswale at Horwith Drive. An option is to improve the bioretention area along Twin Brook Road.

Dry Run Creek measures 407,000 pounds of sediment. Phosphorus is not a measurable problem. The proposal is to improve the Walker Drive basin. An option is to improve the Willow Ridge retention basin. There is also an option to install rain gardens in Howertown Park at Atlas Road and along Route 329.

Catasauqua Creek measures sediment around one million pounds per year. The improvements, along with options, include the Catasauqua High School bioswale, Grube Park rain garden, improvements to drainage along Bullshead Road, bioretention area on Seiple property along the Nor-Bath Trail and a riparian buffer on the Fuller property.

More details and information are available on the Allen Township website, allentownship.org. There is a 30-day comment period open to the public.

The FedEx Ground warehouse property and the proposed warehouse on Lot 5 also have stormwater requirements included in the NPDES permits. NPDES permits are required any time a project disturbs more than an acre of ground.