Dept. of Environmental Protection

Commonwealth News Bureau
Room 308, Main Capitol Building
Harrisburg PA., 17120



Neil Shader, DEP
DEP Lists Susquehanna River as Impaired for Multiple Uses, Develops New Analytic Methods for Semiannual Impaired Waterways Report
Harrisburg, PA – A new report from the Pennsylvania Department of Environmental Protection (DEP) lists four miles of the Susquehanna River as impaired for recreation. The recreation impairment listing joins an impairment for fish consumption for the Susquehanna River, though the listings are not related to smallmouth bass populations in the river. The report also sets forth a groundbreaking protocol to scientifically assess a large river system.

“DEP has dramatically increased the monitoring efforts of the Susquehanna River, and is developing analytic protocols that set the bar for scientific study of large river systems,” said DEP Acting Secretary Patrick McDonnell. “DEP carefully considered the scientific data in preparing this report, and the additional impaired listings in 2014 and 2016 of the Susquehanna River to the impaired waterways list is the recognition of that increased monitoring.”

The listing comes as part of the 2016 Integrated Water Quality Monitoring and Assessment Report (Integrated Report), which was published in PA Bulletin on July 30, 2016. All 347 miles of Susquehanna River are listed as impaired for fish consumption again on the 2016 Integrated Report. The Integrated Report examines water quality for four main uses (water supply, aquatic life, recreation, and fish consumption) of all of Pennsylvania’s 86,000 miles of streams and rivers and 160,000 acres of lakes and ponds. Waterways that do not meet assessment criteria for any one of those four uses are considered impaired.

“DEP staff have deployed continuous instream monitors to be able to identify potential water quality problems before they rise to the level of impairing the river. This kind of proactive approach will provide critical data going forward,” said McDonnell.

The lower section of the Susquehanna River (from Sunbury to the Maryland state line) was also surveyed recently to evaluate the water contact use which includes swimming. As a result, a four-mile stretch – from the mouth of Conodoguinet Creek to the mouth of Yellow Breeches Creek – is added as impaired in 2016. The recreational impairment designation is a result of high densities of coliform bacteria detected in the river, which indicates the potential for other pathogens in the water. High bacteria densities indicate conditions that might cause sickness from contact with or ingestion of the water.

A number of tributaries to the Susquehanna were also listed as impaired for recreation and aquatic life. Tributaries such as Condodoguinet Creek, Swatara Creek, and Conestoga Creek. In the 2016 Integrated Report, a total of 1,665 miles of tributaries to the Susquehanna River were listed as impaired. The full report and supporting documents can be found here

DEP has developed new sampling methodologies and techniques, which have significantly expanded the agency’s ability to assess waters not only in the Susquehanna but all waterbodies across the Commonwealth. Some of these techniques include emerging contaminant sampling, algal composition and toxicity studies, and deployment of continuous data monitors. DEP will use these methods to formulate assessment methodologies in order to make Aquatic Life Use decisions on the Susquehanna River and other large waters.

report released in late 2015 identified likely causes of population decline in smallmouth bass in the Susquehanna River. DEP continues to explore the connections between endocrine disrupting compounds, parasites, and pathogens to smallmouth bass immune systems to determine the likely cause of smallmouth bass decline. These connections do not contribute to the impairment listing for the Susquehanna River.

“Research into the cause of the smallmouth bass population decline is still underway, but we’ve been able to rule out many possible causes,” said Josh Lookenbill, DEP Environmental Group Manager. “That work continues, and DEP and cooperating agencies have been able to focus on identifying the sources of the endocrine disrupting compounds, as well as trying to identify specific pathogens and parasites that are harming the bass.”

The hot weather that has gripped the central Pennsylvania region in recent weeks along with low river flows can create stressful conditions for the river’s aquatic life, and possibly contribute to increased amounts of algae visible in the river. DEP biologists are closely monitoring the Susquehanna River and tributaries. Additional staff and equipment have been directed to monitor the water quality and aquatic life for as long as these critical hot and dry conditions persist.

The Integrated Report listed 19,900 miles of streams and waterways impaired for at least one of their designated uses. The Integrated Report is issued every two years to the Environmental Protection Agency. A 45-day comment period on the report begins on July 30. To submit comments, please visit