DNREC Shares Information on Delaware City Refining Repair Work and Air Monitoring

^{DNREC is advising the public about planned Delaware City refinery repairs that could temporarily increase sulfur dioxide emissions. /DNREC photo}

Delaware City Refining Company (DCRC) has notified the Delaware Department of Natural Resources and Environmental Control (DNREC) it will begin repairs on equipment at its coker carbon monoxide boiler that will cause it to shift from a primary pollution control process to a secondary emissions control. This change to the alternative process means that the facility will be emitting sulfur dioxide at a significantly higher level than normal. This is the same shift to secondary emissions control that happened for 17 days in May-June 2025 while the facility undertook repairs.

DNREC will monitor the situation and fully expects that these increased emissions – which are expected to last for four weeks – will exceed the limits of the facility’s permits and will be assessed for violation and penalties.

For the Delaware City community, DNREC is providing the following information and guidance during this event:

The use of the secondary pollution control process will result in increased sulfur dioxide being released from the facility’s “stack” high in the air, so that it disperses into the atmosphere. Any concern for public health impact would occur if conditions caused the sulfur dioxide to be increased at ground level. A facility can have increased emissions and exceed its permit and still have ambient air readings at ground level remain in the green, or good, range.
DNREC and the public can monitor sulfur dioxide readings at ground level at two DNREC-maintained air monitoring stations in the Delaware City area located east of the refinery on Route 9 and west of the refinery near Lums Pond. That data, updated hourly, is continuously available at de.gov/airdata. Those two stations are part of a statewide network of 11 air monitoring stations for various pollutants.
The U.S. Environmental Protection Agency health standard for sulfur dioxide is 75 parts per billion in the ground level air, when people with asthma or other breathing related issues are advised to limit time outdoors or wear masks to reduce exposure. During the May-June 2025 refinery increased emissions, the highest hourly measurement at DNREC’s Delaware City monitor during the incident was 29.6 parts per billion, and most hourly values over the 17 days were 2 parts per billion or less.

As a result of a DNREC order from a previous incident finalized this week, the refinery has acquired fenceline sensors to measure air quality on the edges of the refinery property and to make that data publicly available. The refinery has indicated four of those sensors are being immediately put into place to begin operations and provide air quality readings; however, the publicly accessible website for those readings has not been completed. DNREC is urging the refinery to complete that website as soon as possible to share information during this period, and until the website is available, also to publicly report out the results on a regular basis until it does.

The public can expect to see notice of these increased emissions from the refinery posted on DNREC’s Delaware Environmental Release Notification System (DERNS), available at de.gov/derns, which provides reports about environmental releases statewide, from small fuel spills to significant air emissions.
After the repairs are complete, DNREC will assess the total level of increased sulfur dioxide emissions for violation and potential penalty. The May-June increased emissions, along with a number of other incidents, resulted in DNREC assessing a $300,000 penalty to DCRC, the maximum allowed by law for those violations. That penalty has been appealed by the refinery to the state Environmental Appeals Board.

Over the last year, DNREC has also been working to expand air quality monitoring and public access to information in and around Delaware City. The Clean Air Council will be installing two community air sensors and partnering with local organizations to engage the community, funded in the state bond bill through efforts of Rep. Melissa Minor Brown and Sen. Nicole Poore, along with DNREC. Through a grant from the Community Environmental Project Fund, the Department is funding additional community-scale air quality sensors to measure sulfur dioxide, nitrogen oxides, particulate matter 2.5, volatile organic compounds and hydrogen sulfide in residential corridors affected by industrial and traffic sources at three locations, including a home in Delaware City.

As part of an Environmental Improvement Project funded through Delaware City Refining enforcement, a PurpleAir sensor to measure particulate matter was deployed at Rose Hill Community Center last week. In addition, DNREC ordered the refinery to install the fenceline sensors following a butane leak in November, has coordinated with the Delaware National Guard and Delaware Emergency Management Agency on possible emergency sensor deployment locations and has begun the regulatory process to require permanent fenceline sensors at some industrial facilities.

DNREC will continue to monitor the refinery’s repair work closely, compare the company’s information with state air monitoring data and keep the public informed as new information becomes available.

About DNREC
The Delaware Department of Natural Resources and Environmental Control protects and manages the state’s natural resources, protects public health, provides outdoor recreational opportunities and educates Delawareans about the environment. The DNREC Division of Air Quality monitors and regulates all emissions to the air. For more information, visit the website and connect with DNREC on YouTube, Facebook, X or LinkedIn.

Media contacts: Michael Globetti, michael.globetti@delaware.gov; Nikki Lavoie, nikki.lavoie@delaware.gov

DNREC Demands Delaware City Refinery Install New Fenceline Air Sensors After Volatile Compound Release

Delaware City Refining Company offices in Delaware City. DNREC has demanded the refinery install fenceline monitors at the facility after a recent release of volatile organic compounds (VOCs) including butane and related compounds produced by the refinery /DNREC photo

The Delaware Department of Natural Resources and Environmental Control (DNREC) has issued an order demanding the Delaware City Refining Company (DCRC) quickly install fenceline sensors at the Delaware City refinery after the facility revealed that a recent release of butane and related compounds was significantly more extensive than initially reported. Butane and the related compounds that were released are flammable volatile organic compounds (VOCs) produced at the refinery.

The Department’s demand follows a release initially reported by the refinery through the Delaware Environmental Release Notification System (DERNS) on Thursday, Nov. 27 as having lasted for less than two hours that afternoon. The company later notified DNREC that the release occurred over approximately 19 hours, from 9 p.m. on Wednesday, Nov. 26 through 4 p.m. on Thursday, Nov. 27.

The Delaware Division of Public Health (DPH) has indicated to DNREC that – based on the information provided – there was likely no threat to public health when the release occurred and no long-term concern. Regardless, DNREC believes additional air monitoring by the refinery is needed given that the incident occurred for a significant period before refinery operators were aware of it, and that DNREC, DPH and the public had no opportunity at the time to evaluate potential impacts from the release while it continued.

Under the expedited order, DNREC demands that DCRC begin operating a real-time fenceline air sensor system 70 days after the order is issued. The system will measure VOCs at the facility’s property line, send alerts when levels rise above a set limit sharing that information with DNREC and the public. If the system detects a release above the limit, the refinery will be required to identify the source and begin corrective action. The parent company of DCRC, PBF Energy, is required to operate similar equipment at its refineries in California.

“Unfortunately, the refinery has had three significant environmental incidents this year and was not aware of this most recent release for some time,” said DNREC Secretary Greg Patterson. “While DNREC has been working toward additional community monitors, demanding that the refinery quickly install fenceline sensors is a step that we believe is now necessary. But it is not the end of our response to ensure future releases can be detected sooner and the public can see the data directly.”

DCRC could choose to appeal the fenceline sensor order to the state Environmental Appeals Board. The Delaware City refinery has also received DNREC Notices of Violation for emissions releases in March and May-June this year, with penalty assessments for these violations still pending.

Butane is an odorless, colorless gas used in aerosol sprays, lighters and some industrial work. The gas released by the refinery contained the same odorant used in natural gas so it could be detected by smell. After being contacted by DNREC, the Division of Public Health (DPH) reported there is no public health threat from this incident. When butane is released outdoors, it quickly spreads out into the air. Because it spreads out so fast outside, it does not lower oxygen levels and does not cause breathing problems, skin irritation or eye irritation for people nearby. DNREC’s Division of Air Quality modeling conducted this week indicates the release was carried east toward the Delaware River on Nov. 26 and 27 and concentrations at the property line and beyond were below occupational health exposure standards, suggesting low risk to ambient air quality in the Delaware City area.

Butane’s main safety concern is that it’s very flammable. Health problems from butane usually happen only in confined, tightly closed or poorly ventilated spaces. In those situations, large amounts can push out oxygen – but that does not happen in open air.

DNREC’s expedited action in demanding that the refinery install fenceline sensors is an initial step in a larger enforcement and rulemaking effort in response to this latest release incident. DNREC is also preparing a broader regulation, expected to be proposed in 2026, that would require expanded fenceline monitoring at refineries and other large facilities. When proposed, that rule will go through the state’s public process, including public comment and a public hearing.

State rules also require the refinery to send DNREC a detailed written report within 30 days of the incident. Once the report is received, DNREC will review it in full and may pursue additional enforcement actions.

DNREC has worked in 2025 with the support of Gov. Matt Meyer, House Speaker Melissa Minor Brown and state Senator Nicole Poore to address refinery issues and expand monitoring in the Delaware City area.

DNREC is also working to install an instrument to measure total VOCs at the department-operated monitoring station located on Route 9, downwind of the Delaware City refinery, to provide additional information.

The DNREC Order can be found on the DNREC website.

Media contact: Michael Globetti, michael.globetti@delaware.gov; Nikki Lavoie, nikki.lavoie@delaware.gov

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Speaker Minor-Brown, Sen. Poore, Gov. Meyer, DNREC Announce Funding for New Air Monitoring Near Delaware City Refinery

The General Assembly, Governor Matt Meyer and the Department of Natural Resources and Environmental Control (DNREC) will fund new community air monitoring around the Delaware City refinery.

Funding just added to the proposed Fiscal Year 2026 Bond Bill at the request of House Speaker Melissa Minor-Brown and Sen. Nicole Poore, along with matching funds from DNREC’s air program, will go to a proposal by the nonprofit Clean Air Council (CAC) for air monitoring and community involvement. The CAC proposal had been awarded grant money by the U.S. Environmental Protection Agency in October 2023, but the EPA canceled the grant in March 2025.

The project, now being funded by the state, will add air monitoring at community locations to be selected by the CAC, and build an understanding of air quality and disaster response among area residents through robust outreach.

“The air we breathe affects everything: our health, our environment and our futures. People deserve to know what’s in the air around them, and reliable monitoring systems and access to real-time information will help them do that,” said Speaker Melissa Minor-Brown. “I know from conversations with community members how alarming it was to see the federal funding for air quality monitoring around the Delaware City Refinery cut earlier this year. And in light of recent events, it’s even more clear how urgently this monitoring is needed. Thank you to everyone who has been vocal about this issue — your tireless advocacy for our community has been vital in helping us to work with DNREC and secure state funding to continue this important work.”

“The recent incident at the Delaware City Refinery has encouraged us to explore preventative measures that prioritize the health and safety of all Delawareans,” said Sen. Nicole Poore. “In addition to the introduction of the Pollution Accountability Act, brought forth in legislation by Rep. Lambert, this air monitoring system will provide another tool to ensure clean air for people living and working in our community. We must keep the health of our constituents as our top priority, and these steps will be vital in maintaining a safe environment for all.”

“The health of Delawareans is non-negotiable, and that means ensuring our air is safe for everyone to breathe,” said Governor Matt Meyer. “By funding this initiative, we’re taking meaningful steps to expand air monitoring across our communities, increase transparency and empower residents with critical information. I want to thank DNREC, Speaker Minor-Brown, Sen. Poore and our legislative partners for working together to protect the health and well-being of Delawareans.”

“DNREC currently operates an air monitoring station near Delaware City to check for air issues caused by the refinery, with the measurements publicly available in real-time,” DNREC Secretary Greg Patterson said. “The Clean Air Council grant proposal addresses recent community requests for additional monitoring in the area, as well as for tools that will help the community understand air issues.”

$250,000 of the project cost is included in the FY26 Bond Bill, which must be passed by the General Assembly and signed by Gov. Meyer in the coming week. DNREC will consult with the CAC and fund the balance.

Media contacts: Michael Globetti, michael.globetti@delaware.gov; Nikki Lavoie, nikki.lavoie@delaware.gov

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DNREC Shares Public Information Sources About Environmental Releases, Air Quality in Light of Refinery Incident

The Delaware Department Natural Resources and Environmental Control (DNREC) has been monitoring the ongoing incident at the Delaware City Refinery as a result of equipment failure first reported on May 26. There are two DNREC tools available to the public that provide information on this and other incidents.

The Delaware Environmental Release Notification System (DERNS), available at de.gov/derns, provides reports from DNREC about environmental releases statewide, from small fuel spills to significant air emissions.

For the current refinery incident, as of 3 p.m. May 31, there have been seven DERNS reports posted with information about the substances and quantities that have been released, along with standard information from public health sources about possible health effects.
The main pollutant released in this incident has been sulfur dioxide.

DNREC maintains an air monitoring station east of the refinery on Route 9, part of a statewide network of air monitors. The daily and hourly data measuring a number of pollutants from the statewide network and from the Route 9 monitor are available from the Air Quality Monitoring Network link at de.gov/airdata.

For the current refinery incident, as of 3 p.m. May 31, the highest recorded daily average sulfur dioxide level at the Route 9 station has been 2.5 parts per billion on May 26 compared to a health standard of 75 parts per billion. (As of 3 p.m. May 31, the May 31 daily average is showing at 7.33 parts per billion, but this is only for part of the day so is not a complete daily average).
The highest hourly measurement during this incident is 25 parts per billion for 6 am May 31, and most hourly values since the incident occurred have been at 2 parts per billion or less.
The Route 9 air monitoring station only measures for sulfur dioxide and particulate matter 2.5, and does not have data for other substances measured at other DNREC air monitoring stations.
Time periods in the Route 9 data plots where there is no measurement displayed for sulfur dioxide are where the measurement was below the minimum detection limit.

The current sulfur dioxide and other emissions are beyond the limits of the facility’s permits and will be assessed for violation and penalties. A list of environmental violations issued by DNREC is at de.gov/violations.

Fines from environmental violations go in part to the Community Environmental Project Fund, which funds environmental projects by organizations in communities near where violations occur. A history of CEPF-funded projects is at de.gov/cfpf

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About DNREC
The Delaware Department of Natural Resources and Environmental Control protects and manages the state’s natural resources, protects public health, provides outdoor recreational opportunities and educates Delawareans about the environment. For more information, visit the website and connect with @DelawareDNREC on Facebook, Instagram, YouTube, X (formerly known as Twitter) or LinkedIn.

Media Contacts:
Nikki Lavoie: nikki.lavoie@delaware.gov; Michael Globetti: michael.globetti@delaware.gov

DNREC, Delaware City Refining Company, LLC agree to penalty settlements on refinery’s outstanding air violations

DOVER – The Department of Natural Resources and Environmental Control (DNREC) announced today that it has signed a settlement agreement with the Delaware City Refining Company, LLC (DCRC) over pending air quality permit appeals and violations concerning the company’s Delaware City refinery. Terms of the settlement agreement call for DCRC to pay an administrative penalty of $950,000, while DNREC through the agreement will provide public notice of proposed changes to the Regulation 1102 permits under appeal by DCRC. Once DNREC issues revised air permits, DCRC has agreed in the settlement to dismiss its permit appeals.

This settlement agreement covers air quality violations at the Delaware City refinery from the June 2010 restart through October 31, 2018, including the violations addressed in the July 24, 2013 Notice of Administrative Penalty Assessment and Secretary’s Order (2013-A-0022). The agreement additionally covers air quality violations through July 2019 related to the refinery’s Coke Storage and Handling Complex.

The settlement agreement can be found on the DNREC website at https://dnrec.alpha.delaware.gov/secretarys-orders/enforcement/.

Media contact: Michael Globetti, DNREC Public Affairs, 302-739-9902

Vol. 49, No. 190