Lawmaker slams Delaware refinery that will increase emissions during repairs: "Extremely unacceptable"
A New Castle County, Delaware, refinery is starting repairs that a state agency warns will increase emissions beyond permitted levels and could impact local air quality.
Delaware City Refining Company is repairing its coker carbon monoxide boiler, a device that captures emissions and converts toxic carbon monoxide into carbon dioxide.
During the repair process, the boiler at the Delaware City facility will begin emitting sulfur dioxide at a significantly higher level. The increased emissions will last for about four weeks, and state officials say this could result in fines and penalties.
The Delaware Department of Natural Resources and Environmental Control says it will be monitoring the situation, and there may be no impact on public health because the sulfur dioxide will be released from the facility's smokestack, high in the air.
There would be concern if sulfur dioxide were detected in the ground-level air. DNREC will monitor ground-level air quality at two sites near the refinery: one to the east and one to the west. Data will be posted online.
After a butane leak in November 2025, the refinery was ordered to install air quality sensors along its property line and set up a website for the public to monitor those readings.
The refinery increased emissions of sulfur dioxide in May-June 2025 during a previous repair, and during that time, the highest measurement of sulfur dioxide was 29.6 parts per billion. Most measurements were 2 parts per billion or less, DNREC said.
The U.S. Environmental Protection Agency's health standard for sulfur dioxide pollution is 75 parts per billion in the ground-level air. At that level, people with breathing issues are advised to limit time outdoors or wear masks when outdoors to limit exposure.
The refinery company, a subsidiary of PBF Energy, received a $300,000 penalty from DNREC, the maximum allowed by law, for last year's increased emissions and other violations.
Delaware House Speaker Rep. Melissa Minor-Brown, whose district includes the refinery, attributed the repairs and upcoming increased emissions to the company's decisions to "delay necessary maintenance despite clear warnings and opportunities to act sooner."
"It is so incredibly disappointing — and extremely unacceptable — that the Delaware City refinery has once again put our community in harm's way," Minor-Brown said in part in a statement. "I'm looking at this situation not only as a lawmaker, but as a parent raising my children just a few miles away. Families in our community deserve to feel safe in their homes and confident that their health and safety are being protected - period, end of story."
Sulfur dioxide has an acrid, burning smell like a lit matchstick and can be threatening to humans in high concentrations.