For more than 25 years, Walter Hang has helped local governments, engineers and homeowners make sense of hazardous waste. To do that, he digs into the enormous data vault maintained by the US Environmental Protection Agency (EPA) and pinpoints information that is useful for his clients to assess the health and financial risks from nearby industrial properties and toxic waste sites.

Hang, who runs Toxics Targeting, now fears this trove of knowledge will become more difficult to access as the EPA’s newly minted chief, Scott Pruitt, begins a broad rollback of regulations and shrinks the agency’s staff. President Trump has vowed to weaken the EPA, contending that its rules for protecting public health stifle business development. The Trump administration has already eliminated or buried some information on EPA websites and moved to muzzle agency employees.

What Trump doesn’t acknowledge is that EPA data isn’t just an enforcement tool. The agency employs more scientists than any other government agency except Nasa. Decades of work by those scientists have generated valuable information about air and water pollution, chemical toxicity and hazardous waste cleanup. This information has enabled businesses to develop new products and services – and create jobs in the process.

No one has estimated the financial benefits of making EPA data easily accessible to the private sector. But anecdotal evidence shows it plays a significant role in many billion-dollar industries, from lending and real estate to renewable energy development and auto designs and manufacturing. For example, chemical companies use the data to come up with less toxic compounds for dyeing textiles.

Banks won’t loan money to a property developer without ensuring that the land is free of contamination, which can be an expensive liability. They rely on pollution data from the EPA, says Hang, who compiles the information into reports for companies in real estate development and transaction.

“We are trying to make sure we get as much data as we can, and we’re trying to make sure we don’t have data gaps,” Hang says.

Hang isn’t alone in worrying about access. Several campaigns, carried out mostly by university professors and students, to download and secure EPA data have sprung up since the November election. One of the first of such efforts began not in the US but in Canada. Matt Price, a history professor at the University of Toronto, helped organize “guerrilla archiving” events in December. Offering free pizza and coffee, these events recruited a small army of volunteers who began downloading EPA data to secure servers.

Price says he and his colleagues sprang into action after experiencing their own “war on science” by former Canadian prime minister Stephen Harper, a conservative who slashed funding for science and ended important environmental monitoring projects. Price and others stepped up to preserve Canadian environmental data during that crisis.

“We probably focused immediately on the EPA because of the extremely hostile language that came out of the Trump campaign around the EPA,” says Price. “We have put a kind of faith in the state as the long term guarantor of the integrity of scientific data. I think that faith may be misplaced.”

Many companies rely on the agency’s data to build products that tackle some of the biggest health and environmental problems. They sign research and development agreements with the EPA, which provides technical assistance in return for a share of any sales a company generates as a result.

EPA had 97 such contracts active in 2015, which yielded $232,318 in royalties for the agency. The previous year, 129 contracts produced royalties of $438,786.

Aclima, a San Francisco company that develops air-quality sensors and software, is working with the EPA to improve the devices’ sensitivity in detecting pollution. EPA air pollution data, gathered for decades at a regional scale, serves as an important reference and quality check for the company. Aclima has partnered with Google to collect air quality data by putting its mobile sensors on the StreetView cars that Google uses to create its maps. It plans to offer the resulting data to the public later this year.

Aclima CEO Davida Herzl says the EPA’s air pollution data plays a “foundational” role in everything the company does. “Anytime we lose information that is important to public health, that is a concern,” Herzl says. “It would be a massive blow to the business community in ways that aren’t always discussed. Innovation and private sector research is happening on top of that foundation of science that EPA has been developing for over 30 years now.”

Even businesses that are set to benefit from Trump’s plan to loosen environmental regulations are worried about losing access to EPA data, which they need for complying with state or local laws and for their own internal accounting of efficiency and performance, says Gretchen Goldman, research director at the Center for Science and Democracy, a program at the Union of Concerned Scientists.

The American Gas Association, which represents natural gas distribution utilities, recently notified members to download any EPA data they need in case it is removed from the agency’s website. Pam Lacey, the association’s chief regulatory counsel, says gas utilities use EPA data and other online resources to track methane emissions, a potent greenhouse gas. The data shows distributors have cut methane emissions by 74% since 1990.

“They continue to do more work and they’d like to be able to keep the data that demonstrates what they’ve done and what they’re doing on an ongoing basis,” Lacey says. “Also, some companies have their own internal goals for sustainability, and they would want to use that official EPA data.”

None of the EPA data has been restricted or eliminated yet, say the scientists involved in the data backup campaigns, but they aren’t taking any chances. Their concern stretches beyond protecting existing EPA data, however. Major budget cuts, if implemented, means the agency may be unable to collect new data.

EPA officials within the Trump administration did not respond to a request for comment.

“Their goal is to defund programs that gather data,” says Jared Blumenfeld, former administrator of EPA Region 9 (California, Nevada, Arizona and Hawaii), who left the agency in May 2016. “It’s much, much harder in a digital age to get rid of data. It’s a lot easier to not fund science so you don’t have the data in the first place.”