There is a vast field in the town of Middlesex, fenced off with barbed wire. “Do Not Enter” signs are posted along the fence. The trees have been stripped away, and the field barely seems to support the grass that grows there.

The 9.6-acre field is an artifact of World War II, when it was part of the Manhattan Project, the top-secret program that created the atomic bomb. The field, at 239 Mountain Avenue, was used to test component materials, such as uranium, thorium and beryllium. But while the bomb was created in a four-year fury of action, and rapidly dropped on the Japanese cities of Hiroshima and Nagasaki, cleanup of the New Jersey site has taken decades.

Lingering Contamination

A chain-link fence was first erected around the then-radioactive site 70 years ago, in 1946. Radioactive waste lay behind it for decades. But over the past 17 years, two 20-foot piles of dirt were removed, abandoned buildings were demolished, and the soil was deemed clean.

Yet there are still signs of water contamination – so the field remains fenced off from public use.

“It has never been the prettiest thing to look at, but at least now it just looks like a field and not a dump,” said a neighbor who asked not to be identified.

The last published test in 2010 found traces of lead and radioactive contaminants in nearby water-testing wells. The U.S. Army Corps of Engineers, which is now responsible for site cleanup, and the office of Middlesex Mayor Ronald DiMura, both declined comment.

But the U.S. Environmental Protection Agency is conducting a groundwater investigation, and using that information to generate a feasibility assessment. It plans to undertake another study in 2017.

The Corps assumed responsibility for site remediation from the EPA 20 years ago.

Initially, area residents were worried that the change in agencies would slow progress. But within two years, the Corps carted away the dirt, demolished some contaminated buildings and added the site to the federal Superfund list.

“As far as I’m concerned I never had any problems with them,” said resident Clem Ianiero, who has lived in a house abutting the field for nearly 45 years.

The fence in his backyard is simply the continuation of the chain-link fence that surrounds the area. It is the house he grew up in, and now owns.

Ianiero remembers when the field and its former buildings first came under investigation. In late 1970s, large amounts of soil, almost 5 feet deep, were removed from all five homes bordering the area.

“We would have to use a ladder to get to the front door,” Ianiero recalled.

He credits the authorities for putting all the soil back, laying down a new sidewalk and seeding the grass in his yard. Whenever the Corps needed to use his land, or to drive over it, the agency would offer to pay his father for the usage. The fence that surrounds his home, which continues into the front yard, was offered in exchange for allowing the agency to remove the trees on the property.

“This entire area used to be full of trees, but now you look around, and there isn’t even one on the block,” he pointed out.

The Middlesex Sampling plant was built in 1943. The covert facility sampled, stored and tested various chemical ores for the Manhattan Project. Its primary focus was uranium testing. By 1950, the sampling plant was still involved in the shipment and storage of bars of uranium, thorium and beryllium. It wasn’t until 1967 when activities here were terminated, and decontamination began.

Decontamination guidelines were much less strict back then. The expectation of the time called for eradication to levels “as low as reasonably achievable.” Thus the area was cleared for unrestricted use, and in 1968 was used as a training ground for the U.S. Marine Corps.

A Radioactive Surprise

Not until 1980, when radioactive material was identified here, did the U.S. Department of Energy designate the land a cleanup site. Upon further investigation, waste was also found to have contaminated the Middlesex Municipal Landfill. Identified materials were transported back to the sampling plant, compacted into two huge dirt piles, wrapped in polyethylene sheaths and placed on top of a large concrete slab.

“I remember coming home from deployment one day, and just seeing two huge piles of dirt and tires. It looked more like a dump than anything else,” recalled another resident whose property abuts the site.

This was the first sign that the cleanup project had started: two 20-foot high piles of radioactive dirt formed in 1986. The piles weren’t removed until 1999.

Next came the demolition of the remaining sampling plant buildings and the concrete slab, in 2005, and simultaneous remediation efforts of contaminated soil and wastewater.

Ianiero recalled how his house would shake during building demolition, as the Corps pounded away at the 3-foot thick concrete walls and floor. He tells this more as a story than a complaint.

Soil remediation was officially finished in 2009. However, the final report still speaks of concerns.

The last soil excavation survey listed two samples as potentially “left in the ground”: one contained the chemical compound Benzo (k) fluoranthene, and the other an amount of lead above regulation criteria.

There are over a dozen testing wells sprouting from the ground of the ex-sampling plant. There is even an underground well, on the street next to a sewer drain.

The well on Ianiero’s property was found to be contaminated. So the Corps paid to connect his home to the town water supply.

The Corp’s project’s management division wrote in a letter to the New Jersey Department of Environmental Protection in reaction to the findings: “Given the extent of the removal action performed and the volume of contaminated material removed at the [Middlesex Sampling Plant] site, and the fact that we only have one slightly elevated lead exceedance that was not remediated and the lead sampling results from survey area 17, we view this to be de minimis.”

The letter also mentions an “attached map” which indicates in “red-highlighted samples or locations” where sample results exceed a measure known as “non-residential direct contact soil cleanup criteria,” or RDCSCC, but may not have been excavated.

When request was made for this map, Corps officials maintained that all material could be found at the Middlesex Public Library. But the map could not be found. Nor was it attached to the published final report.

The letter concludes by requesting the state DEP’s concurrence on the issue, and recommendation that no future action take place. The DEP approved the completion of the soil remediation project.

The Middlesex Sampling Plant site is getting closer to its goal of unrestricted use, but remains on the list of Superfund sites for groundwater contamination.

Although contamination questions linger, Ianiero isn’t worried about any impact on his health.

In the corner of his property, on the edge of the former sampling plant, there’s a small garden. When asked if he had any concerns about how close it was to the one-time radioactive site, he laughed, mentioning how big his tomatoes grow.

This story was awarded third prize in the 2016 New Jersey Student Environmental Reporting Contest,  part of the  Geraldine R. Dodge Foundation-funded collaborative reporting project Dirty Little Secrets: New Jersey’s Toxic Legacy.