The stench of cow feces, urine and ammonia forces residents to keep windows and doors closed in parts of California’s agricultural region. Some people constantly use air purifiers at home to combat odors and, they say, fight air-related illnesses.
“We have a lot of health issues in this community and most of them are respiratory issues,” Beverly Whitfield said amid the dairies of Pixley, a small town in Tulare County. She thinks her allergies, those of her adult son and others are causing respiratory problems. are linked to pollution from neighboring dairies.
Industrial-scale dairy farms are already among the biggest polluters in the San Joaquin Valley, a major agricultural region in the United States with poor air quality. Today, residents like Whitfield worry about methane digesters, which can turn manure into a cleaner biofuel than traditional fuels like gasoline, and could worsen health problems. Biofuel experts say digesters can reduce air pollution.
Home to approximately 1.7 million cows, California is the nation’s top dairy producer and a major contributor of methane. Cow burps and manure emit a powerful planet-warming gas, which, over a shorter period of time, is much more potent than carbon dioxide.
In recent decades, digesters that convert manure and other organic waste into biogas to generate electricity or power vehicles have become widespread across the country.
This figure is expected to increase since waste management practices such as digesters became eligible for funding from the Inflation Reduction Act – President Joe Biden’s legislation to combat climate change.
Most digesters are found in dairies that capture methane from cow manure lagoons and turn it into biofuel. Liquid cow manure is typically stored in a covered digester where microbes from the animals’ digestive systems produce gases. The gas is then cleaned and compressed into a liquid fuel that can be used as an energy source.
Over the past decade, about 120 digesters have been built in California and about 100 more are in the works. But a technology hailed as a cost-effective way to help the state meet its methane emissions reduction goals has become controversial.
Environmental justice organizations say most low-income Latino communities face pollution from nearby digesters and want California to stop providing financial incentives for more. Critics also say state policies favor industrial dairies, reinforcing unsustainable animal agriculture.
Rebecca Wolf, of the environmental group Food and Water Watch, said the state encourages dairies to continue running large, already polluting operations. “You’ll never stop polluting” with this system in place, she said.
Dairies say the state’s financial program plays an important role. “There has to be a financial incentive to give up some of your land to operate these systems,” said dairy farmer Brent Wickstrom, whose digester recently came online.
Supporters point to the technology’s effectiveness in mitigating climate change. AgSTAR, sponsored by the Environmental Protection Agency and the U.S. Department of Agriculture, estimates that manure-based digesters have reduced greenhouse gas emissions by more than 10 million tons of carbon dioxide equivalent in 2022. This roughly represents annual greenhouse gas emissions of more than 2 million tonnes. passenger vehicles.
Supporters note that methane biofuels reduce pollution by replacing fossil fuels like gasoline with cleaner fuel.
“This technology reduces odors and some local air pollutants,” said Sam Wade, public policy director for the Coalition for Renewable Natural Gas. “At the same time, it reduces greenhouse gas emissions.”
People living near dairies complain of flies and strong odors.
“You don’t want the doors open because you’re afraid of all the smells,” said Whitfield, whose family left the doors open when they moved to Pixley in the 1970s. “Everything’s changed now with the dairies.”
Some dairies claim that digester covers that cover the manure reduce odors. “If anything, it should retain some of that smell instead of producing more of it,” said Wickstrom, the Merced County dairy farmer.
Studies have shown that people living near large dairies may experience fatigue, breathing problems, burning eyes and runny noses if the odors are concentrated enough. A 2017 study by the University of Wisconsin found that digesters can increase ammonia emissions by up to 81%. Ammonia can form fine particles that can enter the lungs and bloodstream. Long-term exposure to the coins has been linked to heart and respiratory problems.
“Reducing greenhouse gas emissions is a good thing, but we also need to think about the impact on human health,” said lead author Michael A. Holly, associate professor at the Green Bay campus.
California air regulators said the Midwest study does not necessarily apply to that state’s different weather conditions and digester types. They added that studies are underway to understand the effects of digesters on ammonia emissions.
A recent study funded by the California Air Resources Board found that dairy waste emissions from the San Joaquin Valley contributed little to ozone and fine particulate matter concentrations.
“The air quality implications are virtually zero, and we can actually make a decision about whether to adopt digesters based on greenhouse gas emissions,” said Michael Kleeman, principal investigator of study and professor at the University of California, Davis. “There is already so much excess ammonia in agriculturally rich regions that (digesters) will not significantly influence air quality.”
Maria Arevalo, a 74-year-old activist and former farm worker, believes her asthma and sleep apnea are linked to pollution from dairies near her home in Pixley. She sleeps with a machine to help her breathe. Just like his son, 34 years old, and his grandson, 11 years old.
Her neighborhood often smells of ammonia, she said, but many families can’t afford air conditioning and open windows to let in the breeze. “These dairies should not be located in areas where there are communities.”
In his town of around 4,000 inhabitants, there are more cows than people. According to the Nonprofit Leadership Counsel for Justice and Accountability, Pixley’s 26 dairies house approximately 140,000 cows. Nine of them have digesters operating on farms with thousands of animals, according to AgSTAR.
Recently, 15 members of Congress wrote to oppose USDA’s decision to make certain large-scale agricultural practices, such as roofs and covers of waste management facilities, eligible for federal funding.
“The storage of hundreds of thousands of gallons of liquid manure … pollutes the air and water of surrounding communities,” they said. “This manure storage system, by nature unsustainable, is only further reinforced by… digesters.”
Researchers found that nearly 40% of methane emissions linked to human activity come from livestock and agriculture. The EPA estimates that each cow can produce 154 to 264 pounds (about 70 to 120 kilograms) of methane per year.
In California, supporters see digesters as important in helping the state meet its climate goals and as a source of renewable natural gas for vehicles.
Biomethane improves the air in cities “because trucks don’t emit a lot of emissions when they run on natural gas,” said Eric McAfee, CEO of renewable fuels and biochemicals company Aemetis.
Joey Airoso, who has had a digester on his 2,900-cow farm since 2018, found that odors decreased and the nitrogen-rich leftovers could be used as fertilizer for crops. “It’s a big problem for the environment because it reduces additional nitrogen input,” he said.
Colin Murphy, of the Policy Institute for Energy, Environment and the Economy at UC Davis, said that while digesters have benefits, they don’t solve air pollution “or make life more pleasant for people.” proximity”.
Some Valley residents who have complained of odors and breathing problems say they have been told to move. But many lived in small rural towns long before dairies arrived – and moving isn’t always financially feasible.
“Where are you going to move?” You don’t have money to move,” said Whitfield, the Pixley resident with allergies.