AP A data center and its backup diesel generators built by the Markley Group loom over a ballpark and residential neighborhood June 30 in Lowell, Mass.

LOWELL, Mass. (AP) — Eileen Castle’s swimming pool, one of the only ones for blocks around, was once a refuge for neighborhood children on hot summer days.

But even as temperatures soared this week, Castle, 82, said she won’t be filling the pool — not with the data center behind her house buzzing with the sound of its industrial air conditioners and its backup diesel generators belching fumes at unexpected times.

“I think about the air quality, the water, what effects it has on the kids in the area,” she said on her front stoop as children whirred past on bicycles.

Hot weather of the kind sweeping the eastern U.S. drives up electricity demand for data centers, adding to their strain on power grids and worsening air quality for surrounding areas. The impact on communities like the racially diverse Sacred Heart neighborhood in Lowell, Massachusetts underscores why the artificial intelligence industry is feeling so much heat over the fast-sprouting facilities.

Around the country, data centers have been blamed increasingly for a host of environmental ills. Some tech industry figures say the facilities have become lightning rods for concerns over broader economic and societal changes posed by the AI boom.

But on sweltering days, it’s hard not to see the effects on Castle’s neighborhood, which the state has designated as facing higher environmental and health risks because of a population that’s been historically excluded from political decision-making.

“It’s majority low-income and working family, family members who are working hard every day to just try to put food on the table,” said state Rep. Tara Hong, a Democrat who represents a heavily Cambodian American district in Lowell, a city of about 115,000 people northwest of Boston. “It’s an inclusive place there and that data center is just smack in the middle of everything.”

DATA CENTERS REQUIRE MORE RESOURCES TO COPE WITH HEAT WAVES

A heat wave is “almost the worst situation for data center operation,” said Shaolei Ren, a professor at the University of California, Riverside, who has studied AI’s environmental toll.

A data center’s racks of computer servers run hot and there are two ways to keep them running without interruption, Ren said: refrigeration-based cooling, which is energy-intensive, and evaporative cooling, which is water-intensive.

Some data centers will turn to backup diesel generators as a “preventative measure” to mitigate the likelihood of an outage, Ren said. If the grid is highly stressed, grid operators will sometimes ask data centers to turn on their generators as “the last line of defense,” Ren said.

Diesel emissions can have harmful effects on human health, even with short-term exposure. If too many diesel generators are fired up during heat waves, Ren said that could be “a disaster for the local air quality.”

The operator of the Lowell data center, the Markley Group, said it has planted more than 2,000 trees nearby to improve air quality. CEO Jeff Markley said in a statement to The Associated Press that the company has switched on generators in an emergency only a handful of times.

“They are not run proactively or continuously; they engage only during an actual power disruption to keep critical systems online, plus brief weekly testing of about five minutes per unit, run one generator at a time,” he said.

AS SERVERS HEAT UP, SO DO TENSIONS

Tensions ran so high in Lowell last week that police officers temporarily detained a 14-year-old girl who spoke out of turn at a city-led community forum on data center zoning.

“I’m not hurting anyone,” the girl shouted after police officers escorted her from a middle school auditorium. “We just don’t want data centers!”

A coalition of data center opponents is increasingly clashing with electricians employed by Markley and other data center backers who say the facility boosts Lowell’s ties to the tech industry.

Criticized for calling police to the contentious meeting and later asking an officer to remove the girl, Lowell Mayor Erik Gitschier, whose office is nonpartisan, told local talk radio station WCAP he didn’t know her age at the time and defended his efforts to try to bring decorum to a topic he said deserves debate.

“It was warm out,” he said. “You had people who had definite, passionate positions and they were screaming.”