Machinery used to fracture shale formations stands at a hydraulic fracking, or fracking, site near Mentone, Tex., on March 2, 2017. (Matthew Busch/Bloomberg)

THE TRUMP administration announced late last month that it was tearing up rules on hydraulic fracturing — better known as fracking — on federal lands. The change satisfies drillers who have long opposed federal regulations on the controversial oil and gas extraction process. But it should alarm everyone else.

Though drillers operating on public lands have in recent years fracked extensively, pumping a cocktail of water and chemicals into wells at high pressure to fracture rock formations and free trapped fuel, the Interior Department has not updated its rules in decades. So President Barack Obama's Interior Department spent several years developing new regulations, ultimately releasing them in 2015, well into Mr. Obama's second term. The lengthy process resulted in standards that struck a thoughtful balance between economic opportunity and environmental safety.

For example, the Obama administration's rules would have required drillers to test carefully the cement they use to seal off their wells, which would help prevent leakage into the subterranean environment. They would have stipulated careful treatment of wastewater flowing back out of the ground after injection, insisting that it be stored in aboveground storage tanks rather than in pits. Given that many of the most disturbing fracking accidents occurred in the handling of wastewater, the need for rules such as these was glaring. The Obama regulations also would have obliged drillers to disclose publicly the chemicals they added to the water they pumped underground.

At the time, these standards failed to enthuse some on the environmentalist left, who want regulations that crack down so hard as to hobble the industry or effectively ban fracking. Instead, the Obama administration insisted that the rules would pose little challenge to the industry, because compliance costs would be extremely cheap — a relatively tiny $11,400 per well.

The Environmental Protection Agency underscored the importance of a well-balanced fracking policy in a major report on fracking's safety profile that the agency released at the end of 2016. The EPA found only scattered evidence of harm to drinking water, which is remarkable given the staggering number of wells drilled in the past decade. The agency nevertheless identified several ways in which fracking jobs could go wrong if improperly managed, along with real-world examples of harm.

The industry and the Trump administration would increase national and local acceptance of fracking if strong federal regulations were in place. Instead, the industry argues that states are already doing an adequate job of regulating fracking, so the behemoth federal government need not slow the drilling approval process with yet more red tape. Yet even if most states have model fracking regulations, that does not obviate the need for a federal backstop guaranteeing a minimum level of regulation across the country. The Obama rules would have deferred to local regulations when states had regulations as strong or stronger than the federal ones.

If Trump administration officials were worried about regulatory redundancy, they should have ensured that the federal authorities were deferring to states when they could. Instead, they quashed a sensible set of rules that would have discouraged accidents and encouraged public confidence in the industry.