One of the oldest federally-recognized hazardous waste sites is right here in Louisville. And more than 20 years after the government declared it was no longer a top priority, the site is still contaminating groundwater flowing into the Ohio River, according to the Environmental Protection Agency.

Lees Lane Landfill began its long, sordid life as a sand and gravel quarry in southwest Louisville. Somewhere around 1948, owners got the idea to fill that big, gaping hole with other people’s trash and industrial waste — about 200,000 tons worth.

Today, the garbage pile is leaching arsenic and lead into the Ohio River, according to the EPA’s latest review.

A lot has been done to clean up the site. Back in the 1970’s, methane and other toxic landfill gases seeped into nearby homes in Riverside Gardens, causing flash fires, cancer-causing chromium polluted groundwater and roughly 400 drums lay scattered around the banks of the Ohio River, among other problems.

The EPA said that’s mostly fixed, but there’s still exposed waste (mostly rusty scrap metal and tires), gases rising out of the landfill, on-site pollution… and then there’s the groundwater.

Now, state and federal officials say the site currently protects both human health and the environment, including groundwater. However, the review does note the site needs “groundwater and land use controls” to protect human health in the long-term.

Only about four acres of the 112-acre landfill have a clay cap to prevent water from mixing with the waste and picking up hazardous chemicals. Lees Lane is also inside the city’s 100-year floodplain and has been inundated at least twice, once in 1997 and again last year.

Typically, water in the ground beside a river ends up flowing into the river.

EPA project manager Donna Seadler said she’s not certain why the EPA decided not to clean up the groundwater, but it’s likely because no one is drinking the water.

“So no one is drinking the groundwater at the site. It is going to the river, but no one is drinking the groundwater,” Seadler said.

While presumably no one is drinking groundwater from the landfill, approximately five million people get their drinking water from the Ohio River — including people in Louisville (though the city’s intake is upriver from the site). But because that water is treated before it comes out of the faucet, Seadler said it doesn’t present any health risks.

Jason Flickner, Lower Ohio River Waterkeeper director said officials often expect the massive amount of water flowing through the Ohio River to dilute the pollution.

“The pathway to the Ohio River is probably the way they actually want this to go because they don’t want that pathway to extend back into the community and contaminate wells,” Flickner said.

It’s this philosophy that has previously led the EPA to rank the Ohio among the country’s most polluted rivers, he said.

“Everything we have put into the river is affecting everybody downstream of us, and so what we need to think about is them, as well as hoping that everyone upstream of us is thinking about what they’re putting in the river and sending downstream to us,” he said.

The groundwater pollution at Lees Lane landfill has likely gone on for decades, since people first dumped trash in the quarry.

In 2012, wells testing groundwater at the site found levels of the cancer-causing chemical arsenic above federal limits for drinking water. At its worst, arsenic levels were 38 times federal limits. Meanwhile, the data revealed lead contamination at levels as high as 130 parts per billion.

The worst pollution is showing up in groundwater closest to the Ohio River.

“If you’re showing groundwater contamination, especially in an area like this where you are getting infusion from the Ohio River, especially with the flooding we’ve seen over the recent years, there’s a great amount of concern,” Flickner said.

The pollution coming from the landfill is nothing new for the community of Riverside Gardens.

Originally built as a resort community to escape urban Louisville in the first half of the 20th century, the neighborhood has become a hotbed of environmental degradation.

Besides the landfill, neighbors battled coal ash from the Cane Run power plant (before it converted to natural gas) and cancer-causing volatile organic compounds wafting over from Rubbertown — the city’s corridor of chemical plants.

Over the last few years, the Kentucky Department for Environmental Protection has collected soil and air samples around the site. Regulators have determined neighbors in Riverside Gardens are safe from the landfill’s contamination so long as they don’t walk onto the site, said Energy and Environment Cabinet spokesman John Mura.

“The results of these extensive analyses give a picture of a legacy site that still has contamination within the bounds of the property, but for which there is no indication of immediate or near-term exposure,” Mura said in an email.

Courtesy EPA

However, trespassing at the site remains a problem. The site is pretty easy to access, especially along the Louisville Loop. People are riding ATVs and dirt bikes over the old landfill, scarring the cap and increasing the chances of pollution escaping. Others roam the nearby woods camping and hunting.

That’s something that hasn’t thrilled any of the government agencies involved.

Metropolitan Sewer District oversees the day to day operations of the landfill. They mow, monitor gas levels, maintain signage and check to make sure the most dangerous parts of the landfill are covered, said MSD site administrator Heather Dodd.

She said the district has put up bigger barriers and fences, but that it’s had mixed effectiveness.

“We have tried to put up fencing to keep people out, to limit trespassing, and that doesn’t seem to be terribly effective when people cut through the fence,” Dodd said.