But despite the potential risks ranges pose to their surroundings, they receive little oversight from the federal government. The Environmental Protection Agency does not regulate range design or maintenance. (It does circulate a best practices guide to managing lead from gun ranges.) According to the Times investigation, as of 2014, the Occupational Safety and Health Administration had only inspected 201 gun ranges nationwide. Of those inspected, 86 percent had a lead-related violation.

In many cases, ranges only confront the problem of toxic debris when so much has accumulated that it attracts the attention of local government or outside activists. (Ranges that shoot directly into or near bodies of water are at a higher likelihood of environmental litigation or government action, for example, due to laws protecting wetlands from hazardous waste.) Faced with the prohibitive costs of a massive cleanup, some ranges are forced to close, leaving taxpayers with the bill. As a result, fights over lead decontamination can be contentious, and in some cases have attracted the interest of the National Rifle Association. As reported earlier this week, Marion Hammer, one of the gun group’s most powerful lobbyists, has twice intervened on behalf of a Florida gun range facing high expenses involving environmental concerns.

A similar case raged for the past year in California’s San Francisco Bay. In 1963, the Chabot Gun Club opened an outdoor range on land leased from the East Bay Regional Parks District, just south of Oakland. The facility sat within the watershed of nearby Lake Chabot, a back-up reservoir for drinking water. This March, the Parks District voted not to renew the club’s lease after examining the cost of complying with a new state rule that would require updating the range’s stormwater drainage at a cost of more than $265,000. But the bigger challenge was remediating 50 years worth of lead leftover in the hillside that provided the range’s earthen backstop.

The district initially estimated that removing the lead would cost $1.6 million. By the time of the vote, that quote grew to as much as $20 million. Taxpayers would bear any costs the club couldn’t afford. A group of several hundred people organized by the NRA and the California Rifle and Pistol Association showed up to the Parks District’s meeting to try to sway the vote. Advocates for the club contended the estimated cleanup cost was inflated by officials determined to close the facility from the outset.

In fact, a review of other range clean ups shows the estimated bill for the Chabot to be in line with going rates. Just across the Bay, the city of San Francisco is shelling out $22 million for a cleanup at the site of the former Pacific Rod and Gun Club, which for 80 years operated a trap shooting range on the shores of Lake Merced. Until 1994, the club allowed lead shot, much of which remains in the soil. To ensure the property is safe for any future use, the city will have to replace four feet of topsoil over 11 acres. The city could have faced a far steeper remediation bill had it decided to remove the shot that had also accumulated on the lakebed. It opted not to take that step.