Thousands of us drive past it every day. It started as a hole in the ground in 1954, it is actually two landfills stacked on top of each other, and the public has even been invited to tour it by bus.
Part 1 of a four-part Eyes on EB series.
Come up Edgeboro Road toward the river and you’ll see it long before you get there.
There’s a hill out in that direction. A big one — green, graded, oddly smooth-sided — sitting in a part of town that is otherwise as flat as a parking lot. River lowlands, marsh grass, warehouses, truck terminals. And then this.
Most of us pass it without a second thought. We know the one-sentence answer: it’s the landfill. And then we keep driving.
But that one-sentence answer turns out to be almost comically incomplete. What’s out there isn’t a hill, and it isn’t really a landfill either. It’s an engineered structure, built up in measured layers across seven decades, sitting on top of an older landfill that closed a long time ago. It’s wrapped in monitoring equipment, wired with hundreds of gas wells, and piped under the Raritan River. And it began, of all things, as a hole in the ground.
So what exactly are we looking at?
I found out mostly by accident.
Years ago I signed up for one of the public open houses at the landfill on Edgeboro Road. You get on a bus, they drive you through the facility, somebody talks the whole way.
I want to be honest about my expectations. I figured I’d be polite for forty minutes and then go get lunch.
Instead I found the whole thing genuinely fascinating, and remarkably thorough. But the part that stuck with me wasn’t the machinery or the scale of the place. It was the people who work there.
They were extraordinarily professional. And my clear personal impression — and I want to be careful to call it that, because it’s an impression and not a measurement — was that these were people who actually cared about protecting the environment. Not in a corporate-brochure way. In a “let me explain to you why this matters” way.
They talked about why proper waste handling matters. Why different materials belong in different places. That inappropriate material does sometimes show up at the gate, occasionally concealed on purpose, and that there’s a whole process for catching it. They seemed a little bit annoyed about that last part, which I found reassuring.
That was one afternoon, one person’s impression, a while ago now. It is not evidence about how the facility operates. But it is the reason I eventually went looking for the documents — and the documents turned out to be far more interesting than I expected.
What this series is, and what this part isn’t
This is Part 1 of a four-part Eyes on EB series about the Edgeboro Road landfill.
There is too much here for one article. Genuinely. We spent a long time in state permits, engineering reports, legislative hearing transcripts, county budgets and municipal bond documents, and the story kept getting bigger.
So here’s the plan. This installment answers the simplest question: what exactly is that thing? What are you looking at when you come up Edgeboro Road and there’s a landscape feature where a landscape feature has no business being?
Part 2 will explain how it got so big — and the answer is not the one I assumed. Part 3 covers the part of the story that surprised me most: one Edgeboro landfill genuinely did close, on a legal deadline, and a second one was built on top of it. Part 4 brings it to the present — the disputes, the money, and the question of what happens when the mountain stops growing.
This part is deliberately not trying to tell the whole history. It’s trying to make the rest of it make sense.
It started as a hole
Here’s the detail I like best, and it’s the one that reframes everything.
Before there was a mountain, there was a pit.
A 1987 engineering evaluation prepared for Middlesex County and the Middlesex County Utilities Authority puts it plainly: “Prior to 1954, a sand and gravel quarry owned by the Herbert Sand Company had been operating on a portion of this site.” The same report records that “The Edgeboro landfill has been operating as a sanitary landfill since 1954.”
So the mound began as somebody digging material out of the ground. Then, starting in 1954, material started going back in.
For its first quarter-century, it was a private operation. On January 12, 1979, Edgeboro Disposal, Inc. received a Certificate of Approval from the New Jersey Department of Environmental Protection to operate as a sanitary landfill.
What happened after that is Part 2’s story.
What you’re actually looking at
The active facility is the Middlesex County Landfill, at 53 Edgeboro Road, owned and operated by the Middlesex County Utilities Authority — the MCUA, the same authority that runs the regional wastewater treatment plant in Sayreville.
Some numbers, using only figures our sources actually support:
The site is 315 acres. That number is remarkably stable — the 1987 evaluation gives the site as 315 acres, and MCUA gave the same total in a 2024 public information session. What’s changed is how much of it is under waste. In 1987 the breakdown was 233 acres of designated fill area, 57 acres of leachate treatment ponds and 25 acres of scales and receiving area. In 2024 MCUA described 247 acres of landfill contained within those 315 acres, with the remainder serving as environmental buffer.
Height is where people get tripped up, including us, so let’s be precise about two different things at once.
The permitted ceiling has been raised four times over the site’s life — but not all four belong to the same landfill. The older, private landfill was permitted to 87 feet, later revised to roughly 110 feet. The current county landfill was permitted to 165 feet in 2000, and to its present 220 feet in 2016.
And every one of those figures is above mean sea level — not height above the ground you’re standing on. The site sits in the Raritan and South River lowlands, so the two measures are closer here than they’d be elsewhere, but they are not the same thing, and no source we found gives a height above grade. Anyone who tells you the mound is “220 feet tall” is doing arithmetic the record doesn’t support.
By MCUA’s own account it takes in about 500,000 tons of waste a year, serving all 25 Middlesex County municipalities and over 800,000 residents, six days a week. In January 2026 the authority reported an average of 252 trucks and 1,714 tons a day.
Two landfills, not one
This is the thing that most changes how you see the site, and it’s worth slowing down for.
What looks like one mound is really two landfills from two different eras, stacked.
Underneath is the older, privately owned landfill — the one that operated from 1954. It is closed and capped. On top of and beside it is the active MCUA landfill, which opened on February 5, 1992, after six months of construction.
The federal government has a term for this arrangement. In a 2010 news release, the U.S. Environmental Protection Agency described “this piggyback landfill design, in which MCUA landfill space is constructed on top of the capped Edgeboro landfill.”
Locally, people had already coined their own word for it. At a New Jersey Senate Environment Committee hearing held in South River in May 1993, a legislator testified that “Edgeboro Landfill has the distinction of being the nation’s only double-decker landfill.” We should flag that fairly: that was a legislator’s assertion in testimony, not a verified fact, and we haven’t been able to confirm the “nation’s only” part. But “double-decker” is what people around here were calling it thirty-three years ago, and it’s a good description of what’s physically there.
One warning that will save you confusion for the rest of the series: the name doesn’t tell you which landfill anyone means. In state regulation and in MCUA’s own municipal disposal contracts, the active county facility is also called “the Edgeboro Landfill.” When you see the name in a document, check the date and the described owner.
How and why the old one closed and the new one opened is Part 3. It is a better story than “they said it would close and it didn’t,” which is the version I half-expected to find and which turns out not to be what happened.
How you actually build a landfill
Modern landfills are not holes you throw things into. They’re engineered containers, built in stages, and the specifications are written into the state permit.
Working from the Solid Waste Facility Permit issued by NJDEP for the county landfill, here’s roughly what’s under the waste, from the bottom up:
- three feet of compacted clay, or an approved soil-bentonite equivalent
- a 60-mil high-density polyethylene secondary liner
- 18 inches of sand containing perforated pipes — this is the leak detection layer, whose entire job is to catch anything that gets through the liner above it
- an 80-mil HDPE primary liner
- 18 inches of sand containing larger perforated pipes — the leachate collection layer
Leachate is simply the liquid that percolates through a landfill. The permit requires that the liquid sitting on the liner never exceed one foot deep, which is why the collection layer matters. At Edgeboro, collected leachate is pumped from three drainage areas into the MCUA trunk sewer and treated at the wastewater plant in Sayreville. It doesn’t go into a stream. It goes into the sewer system, like everything else.
The landfill opened in 1992 with three of these lined cells. By 2010 there were nine.
The daily rhythm
The permit gets specific about how filling actually happens, and reading it explains a lot about what you see from the road.
There can be no more than two working faces at a time — the exposed area where trucks are actually tipping. Each face is limited to 150 feet wide, or 15,000 square feet of exposed area. Waste gets compacted in two-foot layers. A day’s lift, including cover, can’t exceed 12 feet. The slope of the working face can’t be steeper than three feet horizontal for every one foot vertical.
Then there’s cover, which is the part I’d never thought about:
- Six inches of material over all exposed waste by the end of every working day
- Twelve inches on anything that will sit exposed longer than 24 hours
That’s why the mound looks like a graded earthwork rather than a dump. It’s covered at the end of every working day. Christine Sullivan, an environmental advocate who took the public tour in 2023 and wrote about it, put it simply: “The landfill is capped nightly.”
When an area is finished for good, it gets a final cap — six layers, including a textured 60-mil HDPE geomembrane, a sand drainage layer, filter fabric, and a foot of vegetative soil on top. That’s what turns a working face into the green slope you see from Route 18.
What gets checked at the gate
This is the part the employees told me about on that bus, and it’s also the part I was most able to verify afterward — which is exactly why I’m separating the two.
The state permit requires the operator to maintain a program for detecting and preventing disposal of hazardous and other unauthorized waste. Its specific requirements include:
- “random inspection of incoming loads”, with inspections recorded
- “training of facility personnel to recognize regulated hazardous waste”
- any truck suspected of hauling hazardous waste is “stopped and inspected”
- “continuous visual monitoring of the discharged waste” — someone is watching what comes out of the truck
- suspect material may not be returned to whoever sent it; it must be segregated, stored securely, and NJDEP notified immediately through its Environmental Action Line
- and the operator must record the name of the hauler suspected of delivering it
MCUA’s own public fact sheet adds that inspectors check for proper waste classification, out-of-county waste, recyclables and banned materials, and that certain industrial waste requires laboratory analysis and pre-approval before it can be brought in at all.
The permit’s list of what’s prohibited is its own kind of education: sewage sludge, bulk liquids and semi-liquids, septic tank clean-out waste, untreated regulated medical waste, hazardous waste, leaves, and anything designated as recyclable under the county recycling plan.
One clarification there, because it matters later in this series: that prohibition is on sewage sludge being buried as waste. Separately, and controversially, a sludge-derived product was for years used as cover material at Edgeboro under a state consent order — which is a different thing entirely, and which became the subject of a serious public fight. That’s Part 4.
None of that proves my impression of the people. It does confirm that the procedures they described to me are real, required, and written down — and that catching concealed material is part of the job, not a story told to visitors.
For what it’s worth, I’m not the only one who came away from that tour impressed. Sullivan, writing in June 2023 as co-chair of a group called Getting Past Plastics — an outside environmental advocate, unconnected to me and not employed by MCUA — described “the landfill’s staff of 30 (many with advanced degrees)” working six days a week, and called it “a highly professional tour.” Hers is an advocate’s opinion column rather than a piece of reporting, and its enthusiasm is her own. But she’s independent, she went, and she reached a similar conclusion.
Gas, wells and a pipeline under the river
Decomposing waste produces methane. A landfill this size produces a lot of it, and the gas has to be captured for safety, odour control and environmental protection.
By MCUA’s account there are roughly 350 gas wells in the mound, connected by piping, feeding a collection system. The gas travels about seven miles by pipeline — running under the Raritan River — to a cogeneration facility in Sayreville, where it generates up to 17 megawatts of electricity that powers the authority’s wastewater treatment plant. Some of the methane is also processed and sold as renewable biomethane.
Notably, the system collects gas from the active landfill and from a closed one. The old landfill underneath is still producing, and still connected.
Beyond the gas system, the permit requires an extensive monitoring regime:
- quarterly methane surveys around the perimeter, checking for off-site gas migration
- quarterly leachate sampling
- quarterly inclinometer readings — instruments that measure whether the mound is moving
- an annual topographic survey of the whole landfill
- a minimum 150-foot setback and a 50-foot buffer zone from the toe of the slope, with that buffer dedicated as open space
MCUA reports 44 groundwater monitoring wells across the site.
Why the groundwater gets watched so closely
The geology under the mound explains a lot.
The 1987 evaluation describes the layers: decades of fill, then organic tidal marsh — silt, clay and peat — originally up to 35 feet thick and since “consolidated to a thickness of four to five feet by the weight of the overlying landfill.” The mound is slowly squeezing the marsh beneath it. Below that sits the Farrington Sand, part of an aquifer the report notes “is used extensively in Middlesex County as a source of groundwater.”
Then the twist. Public water-supply pumping in the region, which the report traces back to 1877, gradually reversed the natural direction of groundwater flow. Water that once drained toward the Raritan and South Rivers now moves inland — so the groundwater, in the engineers’ words, “appears to now transport any contamination towards” the well field doing the pumping. Whatever happens on this site doesn’t simply wash out to the river.
The same report found elevated readings in wells downgradient of the landfill. It listed six possible causes — among them the landfill, older waste outside the containment wall, an adjacent sanitary sewer, and the rivers themselves — and concluded that “The level of information available is insufficient to determine the exact source(s).”
It’s worth being precise about what those readings measured: organic loading, not toxic chemicals. A separate NJDEP memorandum from 1986, testing for priority pollutants, reported “no significant pollution in any of the well water tested.” Both results are in the record. Neither settles the question.
What came after the 1980s — including the odour disputes longtime residents remember vividly — is Part 4.
Birds, deer, and an open house
Here’s something I didn’t expect.
The landfill has a documented wildlife population. Sullivan’s 2023 account reports that the East Brunswick Environmental Commission identified 19 different bird species on the site, including falcons and ospreys nesting there, along with deer.
And that isn’t accidental. The state permit requires implementation of a Wildlife Mitigation and Landscaping Plan, prepared by the engineering firm Malcolm Pirnie in November 1989, to be carried out as sections of the landfill are closed and capped. The habitat is a permit condition with a design behind it, drafted before most of the current mound existed.
There’s one more thing on the property that surprises people: East Brunswick’s own recycling and composting operation is on the Edgeboro Road campus. The township runs a Class B and C recycling center there, redesignated by NJDEP in 2021. Some of what you put at the curb doesn’t just go past the landfill. It stops on the same site.
And some of this has been shown to the public firsthand. The tour I took wasn’t a one-off. MCUA has run public open houses periodically and has offered tours to school groups. For a Saturday morning in June 2026, the authority advertised a tour running about 40 minutes, billed as “an inside look at how the Middlesex County Landfill safely manages nearly 4 million pounds of waste every day,” with a new requirement that guests be age 7 or older.
That’s the authority’s own promotional material, so take the framing as theirs. But the tour is real, and worth taking if the chance comes around again. Forty minutes, and you’ll never drive past that mound the same way again.
What East Brunswick gets
One last number, because it’s the hinge into everything that follows.
East Brunswick is paid to host this. In its adopted 2026 budget, MCUA lists $4,537,000 in host community benefits to the Township of East Brunswick — money the town has been receiving in some form since 1985 under a 1985 state law providing host community benefits to municipalities where a solid waste facility is sited.
It’s a little more complicated than one line item, and the township books it in more than one place, which we’ll untangle in Part 4. But the round number people use — about $4.5 million a year — is close enough to be going on with.
Which raises a question worth holding onto: how did one township end up hosting the disposal site for all 25 municipalities in Middlesex County?
NEXT: PART 2 — How Edgeboro Got So Big
Here’s what I assumed before we started: that at some point East Brunswick, or a company operating here, made a decision to build a very large regional landfill.
That is not what the record shows.
In 1976 Edgeboro took in a few hundred thousand tons of waste a year. Ten years later it was taking millions. Somewhere in between, other landfills in Middlesex County stopped operating — one of them very suddenly — and enormous volumes of waste began arriving on Edgeboro Road, from places well beyond East Brunswick and, in a meaningful share, from beyond New Jersey entirely.
Middlesex County went to court to stop it.
Part 2 is the story of how that happened, who decided it, and why the mountain grew upward.
THE SERIES
- PART 1 — What Is That Mountain on Edgeboro Road? — Current installment
- PART 2 — How Edgeboro Got So Big — Coming soon
- PART 3 — The Landfill That Actually Did Close — Coming soon
- PART 4 — The Fights, the Money and What Happens When the Mountain Stops Growing — Coming soon
Eyes on EB builds its reporting from original records. This installment draws on the 1987 Edgeboro Landfill Evaluation prepared for Middlesex County and the MCUA; the NJDEP Solid Waste Facility Permit for the Middlesex County Landfill; NJDEP permit filings and public notices; MCUA budgets, public information materials and monthly reports; a 2010 U.S. EPA news release; the transcript of a 1993 New Jersey Senate Environment Committee hearing; and a 2023 first-person account of the public tour. Where our sources disagree, we’ve said so.
