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Data centers are putting new strain on California’s grid. A new report estimates the impacts

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Friday, November 14, 2025

In summary A new report estimates that California’s data centers are driving increases in electricity use, water demand and pollution even as lawmakers stall on oversight. California is a major hub for data centers — the facilities that store and transmit much of the internet. But just how much these power-hungry operations affect the state’s energy use, climate and public health remains an open question for researchers. A new report released this week by the environmental think tank Next 10 and a UC Riverside researcher attempts to quantify that impact — but its authors say the report is only an estimate without harder data from the centers themselves. “We are just making these reports pretty much in the dark — since there’s almost zero information,” said Shaolei Ren, an AI researcher at UC Riverside and co-author of the report. “We have extremely little information about data centers in California.” Ren and his coauthors conclude that between 2019 and 2023, electricity use and carbon emissions by California data centers nearly doubled, while on-site water consumption slightly more than doubled. Much of the increases were attributable to the electricity required to run artificial intelligence computations. But many of the report’s estimates, including its health impacts, are based on limited data — a key issue researchers said they encountered repeatedly when crafting the report. The report underscores a growing tension in the industry: advocates who support clean energy and experts who study energy demand agree the days of steady, flat energy use at data centers are over, but there’s far less consensus on just how sharply electricity demand will climb. “In very simple terms, a lot of the uncertainty comes from: what is our life going to look like with AI in the next five years, 10 years, 20 years — how integrated is it going to become?” said Maia Leroy, a Sacramento-based advocate who focuses on clean energy and the grid.  “Are we reaching a point where the use is going to plateau, or is it going to continue?” Experts say more transparency is essential to better understand what resources data centers demand in California. Liang Min, who manages the Bits and Watts Initiative at Stanford University, says the state should improve its forecasts for energy demand to support clean energy goals. Min, who investigates AI’s growing strain on the electric grid, told CalMatters that demand at power centers rises in rapid, unpredictable phases and can shift quickly with each new generation of hardware. The California Energy Commission, which plans for energy use and the growth in demand, “can play a pivotal role,” in understanding and adapting to the demands of AI. As demand grows, policy responses lag In Sacramento, efforts to add transparency and guardrails around data centers have struggled this year. California lawmakers shelved most consumer and environmental proposals aimed at data centers, even as they approved a plan to regionalize California’s power grid to help meet demand from the sector. They set aside two bills focused on curbing data centers’ energy use — one requiring operators to disclose their electricity use and another that offered clean power incentives. Gov. Gavin Newsom vetoed a separate proposal that would have required data center operators to report their water use, even after the bill was weakened. In the end, Newsom — who has often highlighted California’s dominance in the artificial intelligence sector — signed only one measure, allowing regulators to determine whether data centers are driving up costs. Mark Toney, who leads The Utility Reform Network and supported the transparency measure, has questioned whether data centers justify the costs they’re pushing onto ratepayers. He warned of the centers’ “voracious consumption of energy and water, increased carbon emissions, and jacking up ratepayer bills.” Hard facts about data centers are tough to find in California because most rent out power, cooling and floor space to other companies, said Ren, the UC Riverside researcher. Such colocation facilities don’t run their own servers or technology, so they report less information publicly than data centers built by major tech companies in other states. While estimates vary, California has the third-most data centers in the country, after Texas and Virginia. DataCenterMap, a commercial directory that tracks data centers worldwide, lists 321 sites across the state. More in California are expected in coming years. The centers operate around the clock and often rely on diesel backup generators to maintain service during power failures — a practice that adds both greenhouse gases and local air pollutants. They also consume energy and water depending on their cooling methods. Rising data-center demand, and rising questions F. Noel Perry, the businessman and philanthropist who founded Next 10, said his organization’s report shines light on what is fundamentally a black box. “To solve a problem, we have to understand what the problem is,” he said.  “We’ve seen the proliferation of data centers in California, in the U.S. and across the world — and we also are seeing major implications for the environment,” Perry told CalMatters. “The real issue has to do with transparency — and the ability of elected officials and regulators to create some rules that will govern reductions in emissions, water consumption.” The report estimated that data centers used 10.8 terawatt-hours of electricity in 2023, up from 5.5 terawatt-hours in 2019, accounting for 6% of the nation’s total data center energy use. Unless growth is curbed or better managed, the report’s authors project demand could rise to as high as 25 terawatt-hours by 2028, equal to the power use of roughly 2.4 million U.S. homes. Carbon emissions from the sector nearly doubled during the same period, climbing from 1.2 million to 2.4 million tons, researchers estimated, while on site water use grew from 1,078 acre feet in 2019 to 2,302 acre feet in 2023. That’s enough to meet the annual water needs of almost seven thousand California households. The report’s authors also estimated the public health costs from air pollution associated with data centers have potentially risen, from $45 million in 2019 to more than $155 million in 2023, with the burden expected to reach as high as $266 million by 2028. Most of those costs stem from indirect pollution produced by fossil-fueled power plants that supply the grid. But authors pointed out that regions dense with data centers — particularly Santa Clara County, home to Silicon Valley — could face higher localized risks from diesel backup generators. Dan Diorio, vice president of state policy for the Data Center Coalition, said the report exaggerates the impact of backup diesel generators, which are tightly regulated and rarely used in California, minimizing their contributions to air pollution. Data centers don’t control the water used in electricity generation, said Diorio. Since those water impacts don’t happen on site, it’s not fair to blame that on the centers themselves.  “It paints a skewed picture of this critical 21st-century industry,” Diorio said in a statement. Diorio said the report also overlooks how cooling technology varies by region and has become more efficient in recent years. But the authors say their findings underscore the need for uniform reporting standards for data centers’ energy and water use. The report said California should establish ongoing local monitoring and review of data centers — and make the findings public. Ren, the UC Riverside researcher, said that California’s cleaner grid and stricter pollution rules are helping blunt some environmental impacts of data centers already. “California — versus the national average — is doing a better job due to the cleaner grid,” he said.

A new report estimates that California’s data centers are driving increases in electricity use, water demand and pollution even as lawmakers stall on oversight.

Yellow and red cables are plugged into large black shelfs of computer machinery as a person works in the background.

In summary

A new report estimates that California’s data centers are driving increases in electricity use, water demand and pollution even as lawmakers stall on oversight.

California is a major hub for data centers — the facilities that store and transmit much of the internet. But just how much these power-hungry operations affect the state’s energy use, climate and public health remains an open question for researchers.

A new report released this week by the environmental think tank Next 10 and a UC Riverside researcher attempts to quantify that impact — but its authors say the report is only an estimate without harder data from the centers themselves.

“We are just making these reports pretty much in the dark — since there’s almost zero information,” said Shaolei Ren, an AI researcher at UC Riverside and co-author of the report. “We have extremely little information about data centers in California.”

Ren and his coauthors conclude that between 2019 and 2023, electricity use and carbon emissions by California data centers nearly doubled, while on-site water consumption slightly more than doubled. Much of the increases were attributable to the electricity required to run artificial intelligence computations. But many of the report’s estimates, including its health impacts, are based on limited data — a key issue researchers said they encountered repeatedly when crafting the report.

The report underscores a growing tension in the industry: advocates who support clean energy and experts who study energy demand agree the days of steady, flat energy use at data centers are over, but there’s far less consensus on just how sharply electricity demand will climb.

“In very simple terms, a lot of the uncertainty comes from: what is our life going to look like with AI in the next five years, 10 years, 20 years — how integrated is it going to become?” said Maia Leroy, a Sacramento-based advocate who focuses on clean energy and the grid.  “Are we reaching a point where the use is going to plateau, or is it going to continue?”

Experts say more transparency is essential to better understand what resources data centers demand in California.

Liang Min, who manages the Bits and Watts Initiative at Stanford University, says the state should improve its forecasts for energy demand to support clean energy goals. Min, who investigates AI’s growing strain on the electric grid, told CalMatters that demand at power centers rises in rapid, unpredictable phases and can shift quickly with each new generation of hardware.

The California Energy Commission, which plans for energy use and the growth in demand, “can play a pivotal role,” in understanding and adapting to the demands of AI.

As demand grows, policy responses lag

In Sacramento, efforts to add transparency and guardrails around data centers have struggled this year. California lawmakers shelved most consumer and environmental proposals aimed at data centers, even as they approved a plan to regionalize California’s power grid to help meet demand from the sector. They set aside two bills focused on curbing data centers’ energy use — one requiring operators to disclose their electricity use and another that offered clean power incentives.

Gov. Gavin Newsom vetoed a separate proposal that would have required data center operators to report their water use, even after the bill was weakened. In the end, Newsom — who has often highlighted California’s dominance in the artificial intelligence sector — signed only one measure, allowing regulators to determine whether data centers are driving up costs.

Mark Toney, who leads The Utility Reform Network and supported the transparency measure, has questioned whether data centers justify the costs they’re pushing onto ratepayers.

He warned of the centers’ “voracious consumption of energy and water, increased carbon emissions, and jacking up ratepayer bills.”

Hard facts about data centers are tough to find in California because most rent out power, cooling and floor space to other companies, said Ren, the UC Riverside researcher. Such colocation facilities don’t run their own servers or technology, so they report less information publicly than data centers built by major tech companies in other states.

While estimates vary, California has the third-most data centers in the country, after Texas and Virginia. DataCenterMap, a commercial directory that tracks data centers worldwide, lists 321 sites across the state. More in California are expected in coming years.

The centers operate around the clock and often rely on diesel backup generators to maintain service during power failures — a practice that adds both greenhouse gases and local air pollutants. They also consume energy and water depending on their cooling methods.

Rising data-center demand, and rising questions

F. Noel Perry, the businessman and philanthropist who founded Next 10, said his organization’s report shines light on what is fundamentally a black box. “To solve a problem, we have to understand what the problem is,” he said. 

“We’ve seen the proliferation of data centers in California, in the U.S. and across the world — and we also are seeing major implications for the environment,” Perry told CalMatters. “The real issue has to do with transparency — and the ability of elected officials and regulators to create some rules that will govern reductions in emissions, water consumption.”

The report estimated that data centers used 10.8 terawatt-hours of electricity in 2023, up from 5.5 terawatt-hours in 2019, accounting for 6% of the nation’s total data center energy use. Unless growth is curbed or better managed, the report’s authors project demand could rise to as high as 25 terawatt-hours by 2028, equal to the power use of roughly 2.4 million U.S. homes.

Carbon emissions from the sector nearly doubled during the same period, climbing from 1.2 million to 2.4 million tons, researchers estimated, while on site water use grew from 1,078 acre feet in 2019 to 2,302 acre feet in 2023. That’s enough to meet the annual water needs of almost seven thousand California households.

The report’s authors also estimated the public health costs from air pollution associated with data centers have potentially risen, from $45 million in 2019 to more than $155 million in 2023, with the burden expected to reach as high as $266 million by 2028.

Most of those costs stem from indirect pollution produced by fossil-fueled power plants that supply the grid. But authors pointed out that regions dense with data centers — particularly Santa Clara County, home to Silicon Valley — could face higher localized risks from diesel backup generators.

Dan Diorio, vice president of state policy for the Data Center Coalition, said the report exaggerates the impact of backup diesel generators, which are tightly regulated and rarely used in California, minimizing their contributions to air pollution. Data centers don’t control the water used in electricity generation, said Diorio. Since those water impacts don’t happen on site, it’s not fair to blame that on the centers themselves. 

“It paints a skewed picture of this critical 21st-century industry,” Diorio said in a statement.

Diorio said the report also overlooks how cooling technology varies by region and has become more efficient in recent years.

But the authors say their findings underscore the need for uniform reporting standards for data centers’ energy and water use. The report said California should establish ongoing local monitoring and review of data centers — and make the findings public.

Ren, the UC Riverside researcher, said that California’s cleaner grid and stricter pollution rules are helping blunt some environmental impacts of data centers already.

“California — versus the national average — is doing a better job due to the cleaner grid,” he said.

Read the full story here.
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Railroad company appeals water pollution fine after train crash into Oregon river

The Department of Environmental Quality fined the railroad company $81,600 after the January crash.

The railroad company whose trestle collapsed earlier this year, derailing a train into the Marys River in Corvallis, has appealed a fine for water pollution stemming from the incident, denying state officials’ versions of events.Included in the Department of Environmental Quality penalty notice that fined Portland & Western Railroad $81,600 fine was an order that the company inspect all its water crossing trestles for safety concerns and formulate a process for evaluating and prioritizing repairs, modifications or replacement.‘Reckless disregard’In January, the train bridge spanning Avery Park and Pioneer Park gave way under a 19-car freight train carrying pelletized fertilizer, dropping one railcar into the Marys River and leaving another partially in the water.The derailment spilled 199 tons of urea into the river over nine days, according to the DEQ. Urea, which can be synthesized or harvested from animal urine and is used in fertilizer, both sinks and dissolves in water.DEQ alleges the derailment was caused by reckless disregard on the part of Portland & Western Railroad Inc., issuing a civil penalty of $81,600 to the company in a notice made public Friday, Dec. 19.Several attempts, by email and phone, to reach railroad officials went unanswered.The appealPortland & Western Railroad filed an appeal the same day, according to a document provided by the DEQ. The agency initially reported that it wasn’t sure the appeal was filed by the established deadline.The company has requested a hearing with the agency over the penalty and denies several of the DEQ’s findings outlined in the notice.In its appeal, the company denies that the Jan. 4 incident “had a significant adverse impact on human health and the environment.” It also denies that railcars continued to release urea into the river through Jan. 12, as the DEQ alleges.Furthermore, Portland & Western Railroad denies the “characterization of and the related factual allegations regarding the condition of the bridge.” It also denies how the state characterized the railroad’s actions with respect to ”the inspection, maintenance and operation of the bridge.”In its defense, the Portland & Western Railroad appeal claims the bridge failure was an “act of God/Nature,” saying river flooding generated unusually high and fast-flowing water at the time and was a significant contributing factor to the collapse.The state has said urea can pollute water by introducing excessive nitrogen that promotes algal blooms, depletes dissolved oxygen and disrupts aquatic ecosystems. When it breaks down into ammonia, it can be toxic to aquatic organisms.Precipitating event?In May 2022, the trestle caught fire and took nearly nine hours to extinguish. Witnesses reported hearing explosions, possibly from propane tanks at a homeless encampment under the bridge.At the time, a spokesperson for Portland & Western Railroad Inc. said the structure had been “inspected thoroughly” and repairs were made before rail traffic resumed.The DEQ says the company in fact made only “minor repairs” at the trestle damaged in the 2022 fire and ”continued running freight trains over it” rather than replacing it.“Given the threat to human health, safety and the environment posed by a train accident involving freight such as chemicals, disregarding that risk constituted a gross deviation from the standard of care a reasonable person would observe in that situation,” the DEQ said in the penalty notice.As such, the state is demanding Portland & Western reinspect every trestle over a body of water in Oregon.However, in the appeal the railroad company is denying that it operates approximately 478 miles in Oregon. The railroad was bought by Genesee & Wyoming Inc. in 1995 but still uses the Portland & Western name locally.

The U.S. is committed to cleaning up Tijuana River pollution. Will California follow through?

San Diego leaders are calling on California to take stronger action to address the ongoing environmental crisis caused by sewage and industrial pollution flowing from the Tijuana River.

In summary San Diego leaders are calling on California to take stronger action to address the ongoing environmental crisis caused by sewage and industrial pollution flowing from the Tijuana River. As Tijuana River sewage has contaminated neighborhoods in southern San Diego County, the federal government has pledged two-thirds of a billion to clean it up.  Now local lawmakers are calling on California to step up the fight against cross-border pollution, and one introduced a bill this week to revisit air quality standards for noxious gas from the river. State Sen. Catherine Blakespear held a joint hearing of the Senate Environmental Quality Committee and the Assembly Environmental Safety and Toxic Materials Committee in San Diego Thursday to explore how the state can help solve the problem. “California has long been a national leader in environmental stewardship and policy making,” Blakespear said at the hearing. “But what is happening in the Tijuana River Valley is an international environmental disaster that undermines everything that California stands for.” The hearing at Scripps Institution of Oceanography in La Jolla, convened scientists and civic leaders to discuss how failed infrastructure, industrial waste and decades of neglect created the environmental disaster, and what it will take to fix it. “Due to its international nature, we know the federal government must take the lead,” Blakespear said. “Still, there is much that the state and local governments can do.” After decades of stalemate, action on Tijuana River pollution is speeding up. The U.S. Environmental Protection Agency on Monday announced a new agreement with Mexico to plan for wastewater infrastructure to accommodate future population growth in Tijuana. On Wednesday State Sen. Steve Padilla introduced a bill to update state standards for hydrogen sulfide, a noxious gas with a rotten egg smell that’s produced by sewage in the river. Residents in the area complain of headaches, nausea and other ailments when hydrogen sulfide reaches high concentrations. The bill would require the California Air Resources Board to review the half-century-old standard and tighten it if needed. State Lawmakers also aim to improve conditions for lifeguards and other workers exposed to pollution, and hold American companies accountable for their role in contamination of the river. County officials will conduct an extensive health study to measure effects of Tijuana River pollution, and are making plans to remove a pollution hot spot in Imperial Beach. Ongoing, chronic pollution Sewage spills in south San Diego County became common in the early 2000s, sickening swimmers and surfers at local beaches. Then the aging wastewater plants failed, sending hundreds of millions of gallons of raw sewage into the ocean. Last year Scripps researchers found that the river is harming nearby communities by releasing airborne chemicals including hydrogen sulfide gas, which smells like rotten eggs. “The sewage flowing into San Diego County’s Coastline is poisoning our air and water, harming public health, closing beaches, and killing marine life,” Blakespear said.  San Diego officials have successfully lobbied for federal investment to upgrade aging wastewater treatment plants. They also introduced faster water quality testing and surveyed residents to understand health issues.  Paula Stigler Granados, a professor of public health at San Diego State University, said studies of people living near the Tijuana River found “more scary stuff,”  with 45% experiencing health problems, 63% saying pollution disrupted their work or school and 94% of respondents reporting sewage smells at home.  “Children are waking up sick in the middle of the night,” she said. “This is an ongoing, chronic exposure, not a one-time event.” A section of the Tijuana River next to Saturn Boulevard in San Diego on Nov. 21, 2025. Photo by Adriana Heldiz, CalMatters Water samples revealed industrial chemicals, methamphetamine, fentanyl, restricted pesticides, pharmaceuticals and odor-causing sulfur compounds, she said. “This is absolutely a public health emergency,” Stigler Granados said. “I do think it is the biggest environmental crisis we have in the country right now.” That sense of urgency isn’t universal. Last year Gov. Gavin Newsom declined requests by San Diego officials to declare a state of emergency over the border pollution problem, saying it “would have meant nothing.” Over the last two years State Sen. Steve Padilla has introduced legislation to fund improvements to wastewater treatment, limit landfill construction in the Tijuana River Valley and require California companies to report waste discharges that affect water quality in the state, but those bills failed. He said the problem is overlooked in this border area, with its low-income and working class population. “This is one of the most unique and acute environmental crises in all of North America,” Padilla said. “It is underappreciated simply because of where it is occurring.”  Tijuana River solutions This year the U.S. repaired the failing South Bay International Wastewater Treatment Plant and expanded its capacity from 25 million to 35 million gallons of wastewater per day. In April, Mexico repaired its Punta Bandera plant near the border, reducing sewage flows into the ocean. But the Imperial Beach shoreline has remained closed for three years, and residents still complain of headaches, nausea, eye irritation and respiratory ailments from airborne pollution. That problem is worst at a point known as the Saturn Blvd. hot spot in Imperial Beach, where flood control culverts churn sewage-tainted water into foam, spraying contaminants into the air. “When the water is polluted you can close the beach,” said Kim Prather, an atmospheric chemist at Scripps, who identified the airborne toxins. “But you can’t tell people not to breathe.” Community members feel forgotten by state leaders as they face chronic air pollution and years of closed beaches because of contaminated wastewater from the Tijuana River, said Serge Dedina, executive director of the environmental organization WildCoast and former Imperial Beach mayor. “What they say is ‘how come California doesn’t care about us?’” Dedina said. As federal authorities plan expansions to the South Bay International Wastewater Treatment Plant that will boost its capacity to 50 million gallons per day, local and state leaders have their own action plan. A top priority for Aguirre is removing culverts at the Saturn Blvd. hot spot that cause airborne pollution. “That’s low hanging fruit that we don’t need to depend on the federal government to fix,” Aguirre said. She hopes to get funding for that project from Proposition 4, the state environmental bond that voters passed earlier this year. It dedicates $50 million to cleaning up degraded waterways, including the Tijuana River and New River, which flows into the Salton Sea.  The county is also planning a health study that would include physiological measurements to determine the health effects of Tijuana River pollution. “What we’re working on is how are we going to take real, hard medical data and follow a cohort of people who live in this environment, so we can understand what is happening in their bodies,” Aguirre said. “What is happening to children and seniors? What is in their bloodstreams?” San Diego County has distributed about 10,000 home air purifiers to households near the Tijuana River, but Aguirre wants to provide devices to all 40,000 homes in the affected area. Dedina said his organization is removing waste tires that are exported to Mexico and wash back into the Tijuana River Valley. “My lesson here is we need to stop the sediment, the tires, the trash, the toxic waste, the sewage,” he said. In addition to his bill updating hydrogen sulfide standards, Padilla said he’s exploring legislation to regulate pollution created by California companies operating through maquiladoras in Mexico. He wants to work with Mexico “to put some pressure on them to basically clamp down on American companies that are licensed to do business here in California. Blakespear said she wants to protect lifeguards and other public workers exposed to pollution. Whether the solution is creating environmental standards for international businesses or funding costly infrastructure, lawmakers acknowledge that the binational nature of the problem makes it tough to solve. “The complexity around it being an international issue and being a federal issue has added to the difficulties about who should act,” Blakespear said.

Air Pollution Linked To Autoimmune Diseases Like Lupus, Arthritis, Experts Say

By Dennis Thompson HealthDay ReporterWEDNESDAY, Dec. 17, 2025 (HealthDay News) — Air pollution might play a role in people’s risk for developing...

By Dennis Thompson HealthDay ReporterWEDNESDAY, Dec. 17, 2025 (HealthDay News) — Air pollution might play a role in people’s risk for developing autoimmune diseases like lupus and rheumatoid arthritis, a new study says.People exposed to particle air pollution had higher levels of anti-nuclear antibodies, a characteristic marker of autoimmune rheumatic diseases, researchers recently reported in the journal Rheumatology.“These results point us in a new direction for understanding how air pollution might trigger immune system changes that are associated with autoimmune disease,” senior researcher Dr. Sasha Bernatsky, a professor of medicine at McGill University in Canada, said in a news release.For the study, researchers collected blood samples from more than 3,500 people living in Canada’s Ontario region, looking at their levels of anti-nuclear antibodies.Anti-nuclear antibodies are produced by the immune system as part of an autoimmune disease. These antibodies mistakenly target the body’s own cells and tissues.The team compared those blood test results to people’s average exposure to particle pollution, based on air pollution tracking data for their home address.People with the highest levels of exposure to air pollution were 46% to 54% more likely to have high levels of anti-nuclear antibodies, the study found.Fine particle pollution involves particles that are 2.5 microns wide or smaller, according to the U.S. Environmental Protection Agency. By comparison, a human hair is 50 to 70 microns wide.“These fine particles in air pollution are small enough to reach the bloodstream, potentially affecting the whole body,” Bernatsky said.She stressed that such pollution is not just a problem for big cities.“Air pollution is often seen as an urban problem caused by traffic, but rural and suburban areas experience poor air quality too,” Bernatsky said, pointing to wildfires that choke the sky with smoke.The results underscore why standards to reduce air pollution are important, she concluded.“Even though air quality is overall better in Canada than in many other countries, research suggests there is no safe level, which is why Canadian policymakers need research like ours,” Bernatsky said.SOURCES: McGill University, news release, Dec. 15, 2025; Rheumatology, Oct. 22, 2025Copyright © 2025 HealthDay. All rights reserved.

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