What are leaking underground storage tanks and how are they being cleaned up?
For more than a decade, some residents of the small Canob Park neighborhood of Richmond, Rhode Island, drank and bathed in tap water contaminated by gasoline leaking from storage tanks buried beneath gas stations a few hundred feet from their homes. They spent years fighting oil companies, dealing with the daily misery of boiling most of their water and wondering if there would be lasting damage to themselves and their children.
The Canob Park disaster sparked a national outcry in the 1980s to clean up and regulate the thousands of underground tanks across the United States that store petroleum, fuel oil and other hazardous chemicals. It’s a program that continues today, with the tanks a major cause of groundwater contamination even after more than half a million sites have been cleaned up.
___
EDITOR’S NOTE: This article is a collaboration between The Associated Press and The Uproot Project.
___
According to the Environmental Protection Agency, nearly half of Americans rely on groundwater for their drinking water, and it’s not just well water that’s at risk. Although a city’s water supply is treated and processed to ensure it meets federal standards, contaminants from gas leaks can still collect on the way to the tap. In some cases, this can happen when the water comes from an unregulated source (some cities get their drinking water from a mixture of surface and groundwater) or through burst pipes.
For private wells, which are not regulated by the government, the homeowner has the responsibility to treat and filter the water.
Environmental experts say even a pinprick-sized hole in an underground tank can send 100 gallons of fuel into the ground per year, contaminating soil and water. Spills can also destroy habitats and kill wildlife. According to the latest EPA data, about 81 million people live within a quarter mile of an underground storage tank that has experienced at least one leak.
Most tanks were made of steel in the mid-1980s and are likely to rust over time. Modern tanks are made of fiberglass, which is more resistant to corrosion, but all tanks sooner or later begin to leak, said Dr. Kelly Pennell, professor of environmental engineering and water resources at the University of Kentucky. The cylindrical tanks typically hold tens of thousands of liters of fuel.
Detecting leaks is not easy, she says.
“If a gas station has been in business for 10 or 15 years, you might not be able to detect those small leaks,” says Dr. Pennell. “You don’t lose 1,000 liters a day – you lose drops – but over time they matter.”
Leaks can form chemical plumes that move through groundwater and turn into vapor that rises through cracks in the foundation of homes and businesses. Those fumes can contain cancer-causing chemicals, including benzene, an ingredient in gasoline. And they pose the risk of fire and explosion. When contamination was found in Canob Park, the local fire chief sampled drinking water at one of the gas stations and said it was “almost flammable.”
Cleaning up groundwater contamination is expensive, said Anne Rabe, director of environmental policy at the New York Public Interest Research Group, a nonprofit that focuses on environmental issues including leaking underground storage tanks.
“You really need to do extensive testing to determine when these underground storage tanks are leaking and take immediate action or every week it spreads and spreads, and that increases the cost of remediation,” Rabe said.
More than 516,000 spills have been cleaned up since Congress directed the EPA to begin regulating underground tanks in 1984, but more than 57,000 known sites still await a full cleanup, the EPA said.
The average cost to clean up a site is $154,000, according to the Association of State and Territorial Solid Waste Management Officials, an organization that serves as a liaison between state and territorial programs for leaking underground storage tanks and the EPA. But those costs can be much higher or lower depending on how much work is required.
Tank owners are expected to take out insurance and pay cleaning costs, but this does not always happen. A trust fund that receives money from a gas tax helps — it currently has about $1.5 billion — but the program costs states and the federal government about $1 billion a year on top of the fund.
Although leaking underground storage tanks are located in almost every city in the US, those living closest to these locations tend to be in lower-income communities with a higher proportion of minorities, according to the EPA.
The EPA requires owners and operators of underground storage tanks to install approved leak detection equipment and test these systems regularly. But they are not waterproof. There are different types of systems, and each type can miss a leak or its size. Unions suggest building a system that uses more than one leak detection method, but that doesn’t always happen and sometimes the method chosen may not be the best for a particular tank. And owners may not maintain them properly.
Complying with the regulations would cost tank owners and operators a total of $160 million per year – or about $715 per facility per year – according to the EPA in 2015. But it would mean less taxpayer money needed for cleanups, the agency said.
Some of the properties that have been cleaned up since the program’s inception received funding from federal and state brownfield programs, which encourage the cleanup and reuse of contaminated or potentially contaminated sites.
The EPA announced a historic $315 million investment in the brownfields program last year, with most of the money coming from the bipartisan infrastructure deal that President Joe Biden signed more than two years ago.
___
The Associated Press’ climate and environmental reporting receives funding from several private foundations. AP is solely responsible for all content. Find AP’s Standards for Working with Charities, a list of supporters, and funded coverage areas at AP.org.