New Harvard University report projects harmful air pollution from proposed Canadys gas plant

A Harvard University study commissioned by an environmental protection group argues that a proposed natural gas plant headed for the South Carolina Lowcountry will have serious health, environmental and financial impacts for Palmetto State residents, while at least one utility company calls the study a “flawed report.”

The recently released report by the Dominici Lab at Harvard University’s School of Public Health —commissioned by the Southern Environmental Law Center (SELC) — claims to reveal the potential health impacts and related costs of air pollution from Santee Cooper and Dominion Energy’s proposed methane gas plant at Canadys, which is located in rural Colleton County along the Edisto River.

In May, S.C. Gov. Henry McMaster signed into law an energy package that permits Dominion Energy and state-owned utility Santee Cooper to partner on a $2.5 billion, 2,000-megawatt natural gas-fired plant expected to be operational by 2030.

To supply this massive new power plant, these S.C. utility partners have contracted with Elba Express Company, LLC (EEC), a Kinder Morgan company, to construct a 71-mile, underground natural gas pipeline from Georgia, across the Savannah River, through Hampton and Colleton counties in lower S.C., in another controversial project that is expected to impact almost 200 property owners.

“It’s critical for decision makers to understand that the proposed Canadys gas plant would negatively impact air quality and increase healthcare costs for South Carolina residents,” said Robby Maynor, SELC Climate Campaign Associate. “This report projects which areas would experience the most pollution, and how far the pollution would travel. I hope it helps people better understand what’s at stake for South Carolinians with this decision.”

According to the Harvard report, “Emissions modeling revealed that more than two million people would be impacted by additional particulate matter exposure from the gas plant, with the plant emitting annually at least 164.3 tons of particulate matter (also called PM_2.5) – a harmful form of air pollution unsafe at any level of exposure,” states an Oct. 22 release from the SELC.

Particulate matter is a byproduct of fossil fuel combustion and can increase the risk of hospitalizations due to heart attack, pneumonia, cardiovascular issues, or, in some cases, stroke or cancer at even low levels of exposure, stated the release.

“Even with conservative estimates, the projected health impacts from this methane gas plant are concerning,” said Kate Mixson, SELC Senior Attorney. “These findings reinforce our call for a more transparent public process that considers the voices and health of nearby communities.”

Colleton County and surrounding counties, which include Hampton, Jasper and Beaufort counties, would face the brunt of the air pollution but it would travel as far as Georgia, the report and the SELC statement claimed, adding that a “disproportionate number of Black community members and less wealthy residents” would face the most severe air pollution.

This pollution could result in up to $28 million in healthcare related costs annually due to increased disease burden on impacted communities, increasing to $36 million annually by 2040 with inflation, indicated the report.

Air pollution is the single largest environmental risk to human health, responsible for millions of premature deaths each year, says the SELC.

Utility company responds to Harvard gas plant report

Mollie Gore, Director of Corporate Communications and External Affairs for Santee Cooper, called the Harvard study a “flawed report.”

“This is a classic example of the scare tactics this organization trades in,” Gore said in a statement to The Hampton County Guardian. “For example, the report uses photos of stacks with emissions that look dramatic, but the visible emissions are likely water vapor and the stacks are part of a coal plant, not a natural gas station. The Canadys plant will be built in full compliance with protective environmental regulations, and we are engaging with the community there so that they have the facts and not scary, misleading pictures.”

In response to a request for comment, Dominion officials submitted an Op-Ed article, which readers can find in next week’s print and online editions.

More from the Harvard pollution report

The report, completed in October 2025, is based on peer-reviewed research by multiple Harvard researchers using similar existing power plants as models, including one power station in Greenville County, S.C.

Here are more highlights from the report:

• Based on conservative assumptions, the Canadys proposed power plant would emit at least 164.3 tons of harmful PM2.5 per year.
• Over 17% of the plant’s PM2.5 emissions will be concentrated in Colleton County, which will also experience the highest concentrations of additional PM2.5. 66% of all additional emissions will affectSouth Carolina. The remaining 34% of additional emissions will affect Georgia (23%) and Florida (11%), although at lower concentrations of PM2.5.
• Dispersion modeling of those emissions reveals that more than 2,095,000 people would be impacted by additional PM2.5 exposure (at least 0.001 µg/m³) in South Carolina, Georgia, and Florida. Of those, more than 7,737 people in Colleton County, South Carolina would be exposed to additional PM2.5 concentrations greater than 0.1 µg/m3 due to the plant.

More about the Southern Environmental Law Center

According to its website, the Southern Environmental Law Center is one of the nation’s most powerful defenders of the environment, rooted in the South. With a long track record, SELC takes on the toughest environmental challenges in court, in government, and in our communities to protect our region’s air, water, climate, wildlife, lands, and people. Nonprofit and nonpartisan, the organization has a staff of 200, including more than 130 legal and policy experts, and is headquartered in Charlottesville, Va., with offices in Asheville, Atlanta, Birmingham, Chapel Hill, Charleston, Nashville, Richmond, and Washington, D.C.