Philadelphia discharges 12.7 billion gallons of raw, diluted sewage into the Delaware River’s watershed each year, with Camden County adding to the mix, according to a new report.
That’s a problem, say the report’s authors at the nonprofit advocacy group PennEnvironment. Philadelphia and Camden border the river, and significant recreational potential is blocked for part of the year because of pollution from both, the authors say.
A waterway can remain unsafe for recreation for up to 72 hours after an overflow. That suggests local waterways could be unsafe for recreation up to 195 days per year, or more than half the year.
Five decades after the Clean Water Act mandated that waterways be made safe for swimming and fishing, combined sewer overflows (CSOs) continue to pollute during wet weather when untreated sewage and runoff surge into nearby creeks and rivers, creating the potential to sicken recreational users.
David Masur, executive director of PennEnvironment, said the group included Camden County in its most recent report “to get a more holistic view.” PennEnvironment’s first report on CSOs in 2023 focused only on Philly.
The pollution “affects the waterway, the environment, and public health,” Masur said. “The river is the border between the two states, and people on both sides use it a lot.”
PennEnvironment acknowledges that both Philly and Camden County have programs to reduce overflows and is calling on federal officials for increased funding to put proper infrastructure into place.
Frequent overflows, high volume in Philly
Roughly 60% of Philadelphia is served by a combined sewer system, which has 164 outfalls — really large metal or concrete openings — that discharge pollution into waterways. A CSO system uses a single pipe to collect and transport sewage from homes and businesses as well as stormwater runoff from streets and sidewalks.
During dry weather, the system can handle the volume before safely releasing it back into the rivers. But during heavy rainfall, the system discharges untreated, though highly diluted, sewage mixed with stormwater directly into waterways.
Despite the Philadelphia Water Department’s ongoing Green City, Clean Waters project — a 25-year plan focusing on green infrastructure to reduce overflows — the frequency and volume remain alarmingly high, the report states.
Overall, CSOs dumped an average of 12.7 billion gallons of raw sewage mixed with polluted stormwater per year into local waterways from 2016 to 2024, the authors of the report stated. They included an online map to show the location of the outfalls and annual overflow.
Half the sewage came from just 10 CSOs.
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Still, the numbers are a slight improvement over the 15 billion gallons a year released into local rivers, as PennEnvironment reported in 2023.
Philadelphia gets its drinking water from the rivers, but the CSOs are downstream of the city’s treatment plants on the Delaware and the Schuylkill.
The report used publicly available data to show that five of six waterways in Philly produced at least one overflow 65 times or more per year on average between 2016 and 2024. Those were the Delaware River, the Schuylkill, and Cobbs, Frankford and Tacony Creeks.
In better news: The average volume of overflow per inch of precipitation declined by about 16% from previous periods, but progress is slow and threatened by increased rainfall and rising sea levels due to climate change, the authors say.
PWD could not be reached for comment.
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Camden County
The report also found persistent overflows in Camden County. The cities of Camden and Gloucester, along with the Camden County Municipal Utilities Authority (CCMUA), operate combined sewer systems that frequently overflow into the Delaware River and its tributaries, including the Cooper River and Newton Creek.
The report found that systems on the Camden County side of the river overflowed into local waterways an average of 76 days per year from 2016 to 2024.
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The highest-frequency outfall for the Cooper River released sewage for an average of 118 days annually during that period.
The Delaware River received sewage overflows for an average of 94 days annually from its highest-frequency outfall.
The authors said gaps in data leave them unable to show the total volume of diluted sewage released from Camden. But they said that the amount of “solids/floatables” collected at each outfall is an indicator a waterway is polluted.
Dan Keashen, a spokesperson for Camden County, said officials have been making strides.
He said that crews recently cleaned 30 miles of pipe and that a $26 million project is underway to physically separate the combined sewer service area of Pennsauken that flows into Camden. Officials are also studying how to better achieve compliance for the largest outfall in the system, a project estimated to cost $40 million to $150 million when complete.
What can be done?
The report concludes that current plans by Philadelphia and Camden County are insufficient to achieve the goal of a clean Delaware River watershed.
The report was written by John Rumpler, clean water director for Environment America, PennEnvironment’s parent organization, and Elizabeth Ridlington, associate director of the Frontier Group, a nonprofit research group that is part of the Public Interest Network, an environmental advocacy organization.
The authors call for officials to accelerate action to end all sewer overflows, set a hard deadline, and find new ways to pay for necessary infrastructure upgrades.
Philadelphia Councilmember Jamie Gauthier, chair of the committee on the environment, called overflows “a public health crisis” and urged PWD’s new commissioner, Benjamin Jewell, to act. She said elected officials in Harrisburg and Washington also need to step up.
PWD is separately under pressure by a new Environmental Protection Agency regulation that seeks to improve the amount of dissolved oxygen in the Delaware by ordering a large-scale reduction of ammonia at the city’s three water pollution control plants. PWD estimates that the price for compliance is $3.6 billion and would cost households an additional $265 annually on their water bills.
The authors of the PennEnvironment report concede the CSO task is daunting. But they say Portland and Boston faced similar situations, invested in infrastructure, and managed to make CSO overflows infrequent. Washington, D.C., they said, is on track to reduce sewage overflows by 96% in 2030.
Hanna Felber, a PennEnvironment advocate, said that PWD needs to use creative funding, such as floating longer-term bonds to finance projects, and that its engineers need to find more creative solutions, such as installing larger stormwater tunnels that flow separately from sewage.
“Unfortunately, our new report on sewage pollution in Philadelphia shows that on far too many days each year, the Philadelphia Water Department’s pipes and sewer systems dump huge volumes of raw sewage into our beautiful waters, harming our environment and depriving the public of a safe place to fish, boat, and float,” Felber said.
