The nitrogen dioxide detectors kept displaying troubling results: High levels of the air pollutant in kitchens across Montgomery County.

Residents and community advocacy groups formed a coalition to investigate — and found that levels were high everywhere, from newly renovated households to churches and schools. Their “citizen science” campaign aimed to document a relatively little-known public health risk lurking in the intimate spaces where people cook.

Now the Beyond Gas DC coalition, armed with a database of findings and a newly passed state law that requires Maryland utility providers to begin experimenting with geothermal energy projects, sees an opportunity to reduce air pollution in thousands of homes across Maryland.

“We’re pro-breathing,” said Joelle Novey, director of Interfaith Power and Light’s DMV branch, a nonprofit climate advocacy organization that is co-leading the campaign. The message, she said, has gained traction with communities of varying backgrounds, all sharing a common desire to safeguard their families.

The 2024 state law, named the WARMTH Act, calls on Baltimore Gas and Electric Company and Washington Gas Light Company to develop pilot programs that would incorporate geothermal energy — collected underground from the Earth’s natural heat — in low-and-moderate income communities.

BGE has two proposals in the works.

Geothermal energy could help replace natural gas, which during the combustion process forms nitrogen dioxide. Especially in poorly ventilated spaces, the indoor air pollutant has been linked to asthma and other respiratory illnesses.

Washington Gas Light’s project, proposed at the Northwest Park Apartments and the Victory Oaks senior living facility in Montgomery County, would encompass about 230 apartments and 10 single-family homes located off of New Hampshire Avenue and Interstate-495.

The plan calls for the construction of 180 vertical boreholes in the area, as well as a 10,000-foot ambient temperature loop that connects the buildings and 2,750 feet of service lines and indoor geothermal heat pumps. The project also converts the gas oven ranges at the 180 apartments at Northwest Park to electric.

On Tuesday, the Maryland Public Service Commission, which oversees utility providers, will begin considering whether to approve the Washington Gas Light initiative. Already, questions about the project’s expense — which could amount to as much as $70 million and be borne by that utility’s ratepayers — have loomed large.

“The Commission should approve the proposals, if at all, only with significant modifications that would reduce costs,” Maryland People’s Counsel David S. Lapp said in written comments submitted to the Public Service Commission. The Maryland Energy Administration also told the PSC it is concerned about the cost to ratepayers.

Over the last year, gas and electric rate increases — tied to both escalating supply costs and delivery charges that include expenses such as high-end equipment and pricey construction projects— have outraged consumers who are struggling to keep up with their bills.

The cost of the geothermal pilot, if approved, would get spread among Washington Gas Light’s roughly 1.1 million customers, where its impact would be relatively small per bill. But consumer advocates and elected officials say these purchases add up and must be weighed carefully before winning approval.

Members of the Beyond Gas coalition urged the commission to consider the upside. And, with tax credits, state assistance and other rebates, they said, the cost of the project would likely be lower than the estimates suggest.

“How about the cost of health?” said one community organizer who helped lead the nitrogen dioxide testing and trained others to do it, too. She asked The Banner not to identify her for fear of retaliation.

Of the more than 660 homes tested by coalition members, 63% recorded a nitrogen dioxide reading over the federal standard for one hour of outdoor exposure, according to the group’s findings. They’ve begun distributing portable electric induction cooktops and finding creative ways to communicate about the risks in multiple languages.

Silver Spring’s Northwest Park community, among the places where the pilot project would take place, is home to many immigrant families who earn less than the $154,700 area median income. Many school-aged children live in the complex.

Two school parents, who asked not to be identified for fear of retaliation, said they believe such renovations at home could lead to better outcomes for kids at school.

Both have heard concerns from school staff about frequent absenteeism, much of which, they said, has been linked to health problems and doctor’s appointments. Eventually, they began to see a clearer link between students’ exposure to nitrogen dioxide and their respiratory health.

“As a parent, it caught my attention,” one of the parents said, through an interpreter, about the link between student absences and indoor air pollution. They soon learned how to test the gas levels in neighbors’ homes and communicate about the risks.

To sweeten the deal during door knocking, the two parents sometimes offer to make tortillas from homemade dough while they collect their data. Originally from El Salvador, both are wont to cook for their families — papusas, beans and steamy arroz con leche, or rice pudding, are household favorites.

It’s a vibrant, food-centric culture that often demands use of the stovetop. Nitrogen dioxide, or NO2, is among the predominant chemicals released from burning gas and is considered a pulmonary irritant, according to the National Institutes of Health. The U.S. Environmental Protection Agency generally considers anything above 100 parts per billion averaged over one hour as unsafe.

Members of Beyond Gas noted that the risks are disproportionately spread across low-income communities and renters who can’t afford to upgrade their appliances.

The Silver Spring apartments where the pilot program would be applied are some of the area’s most affordable housing, said Tanushree Dutta Isaacman, lead organizer at Action in Montgomery, an interfaith social justice group. She noted that years of use have caked the kitchen exhaust fans in oil and grease, making ventilation difficult.

She also pointed out that Northwest Park Apartments and Victory Oaks’ property managers have voiced support for the initiative, too, calling the pilot a potential “model” for the rest of the state. The property managers support the utility company’s proposal.

The NIH says that homes with poor ventilation can carry serious respiratory health risks for those who use gas stoves, particularly related to asthma and wheezing. After a December 2022 paper documented the link between childhood asthma and gas stove use, a U.S. Consumer Product Safety commissioner warned that the appliance could be banned. A swift public backlash, forged along political lines, and countless memes, ensued. The commission later walked back the comment.

Researchers, government officials and climate advocates in Maryland have embraced the WARMTH Act, calling it an important step to achieve the state’s goal of reducing greenhouse gas emissions and eventually reaching net zero emissions. The switch to electrification and renewable energy, they said, would result in consumer cost savings and help allay health hazards.