Leaking underground fuel tanks threaten to contaminate drinking water, lakes, streams and homes across Iowa as environmental officials change rules to speed up detection and cleanup.
There are about 6,200 leaking underground storage tanks in the state — and more than 1,500 are considered ongoing contamination risks. Some of the leaking tanks have been problems for more than 15 years. Almost 820 are labeled high-risk.
State officials say they are trying to devise new rules so that the most hazardous sites, which often take years to clean up because of bureaucratic red tape and legal wrangling, can be addressed faster.
See where they are: Click here to search a map and database to see how many of the state’s 6,200 leaking underground tanks are near you.
The state’s backlog is down about 30 percent from five years ago, according to statistics from the Environmental Protection Agency, but about 20 leaking tanks deemed in need of action are on school property.
“We are taking enforcement action against those who don’t fix (leaks),” said Elaine Douskey, who supervises the underground storage tank program with the Iowa Department of Natural Resources. “We are staying after them.” Left undetected, leaking tanks can cause big problems, as residents in Climbing Hill, an unincorporated town of less than 150 people in Woodbury County in northwest Iowa, discovered.
They learned almost 18 years ago that two underground tanks, including one that belonged to a school, contaminated five residential drinking water wells and one public supply well that belonged to a restaurant. State officials provided bottled water for almost nine years and then switched the town to filtration systems before homeowners received new wells around 2004, said Rochelle Cardinale, an environmental coordinator with the DNR.
Routine tests show the new wells are safe, but some residents still question whether lingering contamination will someday taint that water supply, too.
“I’m worried about where that contamination might go,” said Gary Little, who works and lives with his family in the Barn, a local cafe.
Longtime residents are also concerned about developing cancer, he said. “They don’t know how long they’ve been drinking that stuff.”
People who ingest or breathe high concentrations of chemicals released from a tank could wind up with leukemia, kidney damage, nervous system disorders and other ailments, according to state public health officials.
A report by the Iowa Department of Public Health estimates Climbing Hill residents were exposed to chemicals, including benzene, for a year or two before the leak was detected. That wasn’t long enough to put them at greater risk for getting cancer, the report states.
The Climbing Hill leaks are still labeled high-risk; there is still benzene in the soil. In high enough concentrations, benzene can cause leukemia.
The site might be downgraded because the wells have been removed, Cardinale said. The department isn’t sure how much longer it will have to monitor the area, she said.
The high-risk designation means a leak could expose people to dangerous chemicals. It doesn’t mean contamination has already occurred.
Challenges exist in finding, tracking tanks that leak
DNR officials know how many leaks there are, but say they don’t keep track of how many times leaking tanks have tainted drinking water, polluted lakes or streams, or seeped into basements in Iowa.
Douskey said the agency’s data on the leaks have that detail, but the only way to tally up that data is to review each file manually.
However, the agency does respond quickly to reports of suspected contamination – either in the water or the air, which sometimes is the first clue there is a leak nearby, Douskey said.
One example is from February 2006, when employees at a day care in Shelby said tap water smelled like gasoline. The likely culprit was a plastic water line running past a gas station. The day care moved and the lines were replaced.
But without evidence of contamination, it’s not readily apparent to residents whether a leaking underground storage tank near them poses a hazard because each site is different, Douskey said. Soil composition, the size of the tank, the depth of nearby wells, the age and extent of the leak, and the groundwater table all factor into where pollutants are likely to spread and whether they present a risk to the public.
“If I lived right next door to a gas station, I would be curious whether they have a plume under that site,” Douskey said, adding that anyone can view the agency’s records on leaking tanks for more information.
If a leak occurs in clay soil, it could stay on the site forever and never be a problem, but a leak in sandy soil travels farther, she said. But even if it spreads, that doesn’t mean it’s a risk, she added.
Leaking gasoline tanks can also present the risk of fire and explosion because vapors travel.
When a leak is detected, state officials inform residents and businesses within 100 feet of the affected area, and they take soil, water and air samples if they suspect any contamination, Cardinale said.
Cardinale said it’s unusual for a leak to travel much beyond 400 feet, or about a city block. The leak could spread farther if it’s near a municipal well that pumps lots of water and can pull contaminants in.
Tracing contamination, cleanup can take years
It took 14 years for officials to figure out how to handle the Climbing Hill contamination. That case was extreme, but cases sometimes linger several years while agencies and owners decide what to do, Cardinale said.
The agency and the industry admit it often takes far too long to take action, and both sides are trying to implement new methods to speed up detection and cleanup. Aided by new federal laws, state regulators also have more tools to guarantee that tank owners comply.
Some of the changes include:
• Devising a better way to measure the actual potential spread of contamination, which could downgrade some sites where the current risk might be overstated, although industry officials and the DNR are currently at odds over how to do this.
• Using inspectors from third-party companies to check all tanks every two years. State inspectors had such a backlog that some sites went five years without an inspection.
• Shutting down gas stations or fueling facilities that don’t comply by preventing fuel trucks from filling the stations’ tanks, in accordance with a federal law that went into effect last year.
• Requiring all new tanks to have enhanced safety measures, leak detection devices and an extra outer shell. Traditional steel tanks, prone to corrosion, have been replaced with specially coated Fiberglas tanks resistant to gasoline, diesel and ethanol.
• Bringing all parties together at once, especially for high-risk sites that need more attention.
“If we know it’s high-risk, we decided it’d be best to get everybody at the table at the same time,” Douskey said. “That seems to have cut the time down significantly.”
Jeff Hove, regulatory affairs manager of the Petroleum Marketers and Convenience Stores of Iowa, agreed. “Especially if it’s a newer release, you’re going to see it move forward immediately,” he said.
But about three-fourths of the remaining cleanup work in Iowa must be funded by taxpayers.
Evaluating a leak requires rounds of monitoring and testing to figure out how far contamination has spread. It’s a problem if pollutants reach private drinking water wells, city water supplies, sewer lines, lakes or streams, or seep into basements as a chemical vapor.
If the current property owners didn’t install the tank — or knew nothing about it when they bought the land — finding out who is responsible adds another hurdle.
Debating whether to excavate the soil, remove the tank, extract vapors or take other action turns into back-and-forth between government agencies and site owners, Hove said.
“It can be a really long process,” Hove said. “Sometimes the regulator will say, ‘Well, industry’s dragging their feet.’ And industry says, ‘We did our report and sent it in 12 months ago and it hasn’t been reviewed by DNR yet.’ ”
Eastern Iowa school district spends thousands on site
In the meantime, some site owners simply watch and wait. Near an elementary school in Lowden, a town of about 800 residents some 40 miles northwest of Davenport, inspectors test six groundwater samples each year.
Leaks from an old fuel oil tank used to heat the school’s boiler are in proximity to a city drinking water well. That means the site has been labeled high-risk, even though the tank was removed in 2004 and the tests show contaminant levels falling within allowable ranges, said Mary Jo Hainstock, superintendent of the North Cedar Community School District.
The district spent about $14,200 in 2004 to have the tank removed and has been paying $1,300 to a private company each year since for the tests.
“It’s thousands of dollars,” she said. “But when you want to do things right, it’s really not an option not to do it.”
The district hopes the state will reclassify the site soon, although Hainstock is prepared to wait up to a year for her district’s application to be reviewed.