Why 23 Billion Gallons of New Jersey Sewage Flow Into Rivers Every Year

Jul 22

6 min read

Every time it rains hard in Newark, Camden, Jersey City, or eighteen other older New Jersey cities, something happens that most residents never think about: raw sewage starts flowing directly into the nearest river. Not from a broken pipe or a system malfunction. This is the system working exactly as designed, because these cities still run on sewer pipes built more than a century ago to carry stormwater and sewage through the same tunnel. When heavy rain overwhelms that shared pipe, the mixture has nowhere to go but into the Passaic, the Delaware, the Hackensack, or Newark Bay.

New Jersey's combined sewer systems dump more than 23 billion gallons of untreated sewage and stormwater into the state's waterways every year. Fixing this problem is now underway, decades behind schedule and likely to take decades more.

How a Sewer System Is Supposed to Work

Most sewer systems built after the mid-twentieth century use two separate networks of pipes. One carries sewage from toilets, sinks, and drains straight to a treatment plant, where it's cleaned before release into a river or bay. The other carries stormwater runoff from streets and roofs into local waterways, untreated but also mostly free of anything dangerous since it's just rain.

Twenty-one older New Jersey cities never made that switch. Their systems combine both types of waste in a single pipe, a design that made sense when it was built in the late 1800s and early 1900s, since running two separate pipe networks through a dense city cost more than anyone was willing to spend. On a dry day, that combined pipe carries sewage to a treatment plant just like a modern separated system does. The trouble starts when it rains. A heavy storm can send far more water into the pipe than the treatment plant can process. Engineers built a relief valve into the design called a combined sewer overflow, a point where the pipe simply discharges directly into a nearby river once it hits capacity, sewage included. Without that release valve, the excess water would back up into basements and streets across the city instead. The overflow point is the intentional compromise. It protects homes by sending the mess into the river instead.

New Jersey has 210 of these overflow points across its 21 combined-sewer cities, each one a spot where an old design decision is still shaping water quality more than a century later.

Where the System Breaks Down Today

The core problem with combined sewers isn't really about pipes failing. It's about a design built for a smaller, drier city now serving a much larger and increasingly wet one. Storms have grown heavier as the climate has changed, and the pipes weren't sized for that. In cities like Camden, roughly 220 million gallons of combined sewage and stormwater overflow into the Delaware and

Cooper Rivers each year, according to county officials tracking the outflow.

Underneath that structural mismatch sits a second problem: the pipes themselves are old. Jersey City's Municipal Utilities Authority spent years releasing untreated sewage into the Hackensack River, the Hudson River, Newark Bay, and Penhorn Creek because it wasn't properly maintaining its combined system, according to a Justice Department Clean Water Act settlement. The fix required more than $52 million in infrastructure investment and repairs to roughly 25,000 feet of sewer line, along with a $375,000 civil penalty. Pipes that have sat underground for a century develop cracks, root intrusion, and joint failures independent of whatever else is going on with stormwater capacity, and every one of those problems adds more points where the system can fail.

The health and environmental cost of all this falls hardest on people who live near the rivers these systems empty into. Bacteria levels spike after storms, closing beaches and making waterways unsafe for fishing or swimming for days at a time. The neighborhoods closest to these outfalls also tend to be lower-income, so the burden of a Victorian-era engineering decision lands disproportionately on communities that had no say in how the system was built.

The Fixes Being Built Now

Some solutions focus on separating what should never have been combined in the first place. Camden County's $400 million initiative, approved for its first phase over roughly ten years, will physically split Pennsauken's combined system into two, sending stormwater straight to the Delaware River and sewage to treatment, at a cost of about $200 million for that piece alone. It's expensive because it means digging up streets and laying an entirely new pipe network, but it eliminates the overflow problem in that section permanently rather than managing around it.

A cheaper approach relies on green infrastructure: rain gardens, permeable pavement, and roadside plantings designed to soak up stormwater before it ever reaches the sewer pipe. Newark has installed dozens of these sites across the city, each one built to catch runoff from a specific block or intersection and let it filter into the ground rather than adding volume to an already strained pipe. Green infrastructure doesn't fix the underlying pipe, but it reduces how often the pipe actually overflows, since less water shows up in the first place.

For fixing the pipes themselves, engineers increasingly use a technique called cured-in-place pipe lining, which lets crews rehabilitate a sewer line without digging up the street above it. A resin-soaked liner gets inserted into the existing pipe, inflated to press against the walls, then hardened in place, creating a new pipe within the old one. It's a fraction of the cost of full replacement and can be done street by street without the years of disruption that trenching would require.

None of these approaches works alone. New Jersey's regional Long Term Control Plans, the formal roadmaps each utility must file with the state to bring its combined sewer system into compliance, typically combine all three: some physical separation where it's most cost-effective, green infrastructure to reduce volume everywhere else, and pipe rehabilitation to keep the existing system functioning in the meantime.

The Policy Fight Underneath the Pipes

New Jersey's Department of Environmental Protection has required each of the state's 21 combined-sewer utilities to submit a Long Term Control Plan laying out exactly how they'll bring overflows into compliance with the Clean Water Act. As of 2026, six of the seven regional plans have been finalized. That sounds like progress, and it is, but the plans themselves stretch 30 to 40 years into the future, a timeline utilities say is necessary to spread the cost across generations of ratepayers rather than hitting anyone with an unmanageable bill all at once.

That financing question is where most of the real fighting happens. Fixing New Jersey's combined sewer problem will cost billions of dollars, and under state law, the utilities running these systems recover that money through rates charged to the households and businesses they serve. Cities with combined sewers tend to also be some of New Jersey's poorer communities, which creates a direct tension: the places least able to absorb a rate increase are the same places required to pay for a fix to a problem their own infrastructure never should have had in the first place. Some funding flows through the New Jersey Infrastructure Bank, which offers below-market loans for water projects, but demand for that financing consistently outpaces the state's capacity to provide it.

There's also a harder governance question sitting underneath the money. Federal Clean Water Act enforcement, like the consent decree that forced Jersey City's hand, can push a utility to act faster than its own long-term plan calls for. That creates a mismatch between the deliberate, decades-long timeline utilities have built into their compliance plans and the more urgent pace that court orders or public pressure can demand. Nobody has fully resolved which pace actually governs, and utilities are left managing both timelines simultaneously.

What's Still Unresolved

New Jersey's combined sewer overflow problem is a known quantity now in a way it wasn't a decade ago. Every affected utility has a plan, most of those plans are finalized, and money is moving toward green infrastructure, pipe separation, and rehabilitation projects across the state. What's not resolved is whether 30 to 40 year timelines are actually fast enough, given that climate change is intensifying the storms these systems have to handle in the meantime. It's also not resolved who ultimately bears the cost of fixing a nineteenth-century engineering shortcut that current residents didn't create and can't easily afford. Every heavy rainstorm between now and whenever these plans finish is another reminder that the fix is still decades away.

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