Stop at any gas station in Nevada, and one feature will likely remain the same whether the gas being pumped is in Elko or Las Vegas — the fuel is stored underground.

For most people, underground storage tanks where gasoline is typically stored is typically out of mind and literally out of sight. But of the roughly 14,000 underground storage tanks registered with Nevada authorities — more than 4,600 currently in use — state environmental officials are actively investigating or overseeing cleanups from leaks at nearly 200 sites throughout the state.

From dozens of gas stations scattered around North Las Vegas to ghost towns such as Coaldale, state environmental officials are constantly chipping away at the backlog of leaky or contaminated areas around the storage tanks — between the end of May and beginning of September, the state added 6 new cases including a petroleum park in rural Eureka and five in Clark County.

Clean-up efforts vary depending on the type of soil, location of the spill and if it reaches any groundwater, though state environmental officials stress that the vast majority of leaks don’t reach “catastrophic” levels.

But environmental groups have warned that those clean-up efforts could soon be in jeopardy, given that President Donald Trump’s administration has proposed cutting grant funding for leak prevention and cleanup by nearly half, from $92 million to $47 million dollars per year — even as federal regulations upping standards for the tanks are set to take effect next year.

“When leaking tanks are at risk of leaking harmful chemicals such as oil, gas, benzene and toluene into soil and groundwater, drinking water and soil are fouled, backyards and businesses become dangerous, community health is jeopardized, and economic development is crippled,” the Environmental Defense Fund wrote in an August report.

Although it’s a tiny part of the overall EPA budget, it’s led to concerns of a potential slow down in efforts to clean up the backlog of nearly 70,000 tanks nation-wide that have reported leaks or have lingering residual contamination.

The effects could also be felt sharply in Nevada — the state took in more than $740,000 in federal EPA grants to help fund leak prevention and cleanup during the most recent fiscal year, with funds helping pay for inspectors with the state’s environmental protection agency and several case officers who oversee the cleanups.

Jeff Collins, ‎head of the Nevada Division of Environmental Protection’s Bureau of Protective Action, said that the office’s approximately six case managers who (in addition to other duties) oversee spill cleanups wouldn’t necessarily be at risk of reductions due to a loss in grant funding, but noted that the department didn’t know what kind of cuts Congress would end up making.

“We feel like our case officers and the folks that are working here are never necessarily going be in jeopardy of their position just because there’s one particular grant cut,” he said. “We might have to work a little more lean if there’s a significant cut across the board with grants, but that’s something that we’re going to have to work internally here to understand if that time came.”

In addition to the grant funds, the office (which receives no state funding) pays salaries and ongoing operations through a variety of sources, including hazardous waste tipping fees and the state’s “Petroleum Fund.”

Established in 1989 to comply with the federal government’s first set of regulations on underground storage tanks, Nevada’s Petroleum Fund charges each tank owner an annual $100 invoice and a $0.0075 fee on each gallon of gas refined or imported into the state as a state-managed insurance program to help fund the cost of preventing or cleaning up leaky tanks.

After lawmakers approved a special session bill in 2010, any revenue over $7.5 million in the fund is transferred to the state’s highway fund, dedicated to construction and maintenance of state highways. It’s sent an average of $4 million to the fund every year since then.

The fund has doled out more than $216.3 million to clean up spills or leaks at more than 1,530 sites that have applied for cleanup funds since it was established 28 years ago.

Lawmakers in 2017 approved a measure creating a grant process for rural tank owners who have demonstrated financial need to update their tank infrastructure to comply with federal regulations. A 2015 update to underground tank regulations — the first major revision since 1988 — is scheduled to take effect in October 2018, and gas stations built since April 2016 have already been complying with the new regulations, which require more regular inspections and additional precautions, such as a double-walled “spill bucket” surrounding intake pipes and more regular inspections.

The clean-ups themselves are typically reimbursed through the Petroleum Fund, and vary in cost depending on soil type, level of contamination and if the leaks have reached groundwater reservoirs — a precious resource in water-poor Nevada.

Collins said the primary concern with leaks was over concerns that so-called BTEX compounds (benzene, toluene, ethylbenzene and xylene), chemicals that occur naturally in crude oil and are known cancer-causing agents. He said that clean-up efforts vary in terms of difficulty, from simply removing contaminated soil around a leak to “air sparging,” where clean-up crews inject pressurized air into groundwater deposits, similar to blowing bubbles through a straw in a glass.

“First and foremost, that’s our job, to understand if there’s potential human health risk associated with these releases,” he said.

Kyle Davis, a longtime renewable energy lobbyist and former political director of the Nevada Conservation League, said that leaks from underground storage tanks could threaten groundwater sources relied upon for drinking water throughout the state, but that other concerns such as the state’s Superfund sites and ongoing mining operations loomed larger.

“Those types of things are a bigger concern, because the ability they cause bigger impact, but not to say that underground storage tanks aren’t something to be aware of,” he said. “It’s a legacy issue, that is one that doesn’t come around anymore, but it’s something that we’re going to have to continue to clean up.”