378,000 Gallons of Gasoline Leaked Into a Pennsylvania Neighborhood While the Company Handed Out Gift Cards

The Leak They Tried to Call “Maintenance”

On March 3, 2025, Monroe Energy—through its wholly owned subsidiary MIPC, LLC (Monroe Interstate Pipeline Company)—returned Tank 708 to active service at the Chelsea Tank Farm in Aston, Pennsylvania. The tank had been pulled offline in July 2024 after internal corrosion was discovered. It measured approximately 144 feet by 58 feet and had a capacity of roughly 151,111 barrels. It was installed in 1951. It was 74 years old.

Within hours of being returned to service, gasoline began leaking from a manmade hole in the floor of the tank. The leak would continue for nine months.

By the time Monroe Energy finally disclosed the situation to federal regulators and the public in December 2025, at least 9,000 barrels—378,000 gallons—of gasoline had been discharged into the underlying soil, bedrock, and groundwater. The contamination plume migrated off the Tank Farm property and into the surrounding residential neighborhood, where families like Brian and Michelle Mielnik and their four children (ages 8, 12, 14, and 16) were living their lives, unaware that the air they were breathing and the water beneath their homes had been poisoned.

The Chelsea Tank Farm is located in a high-consequence area as defined by the Pipeline and Hazardous Materials Safety Administration (PHMSA). It is surrounded by residential homes. It contains 12 hazardous-liquid breakout tanks with a total storage capacity of approximately 1.7 million barrels. Monroe Energy uses these facilities to store, distribute, and transport jet fuel and gasoline refined at their Trainer Refinery in Delaware County, which they then ship into Philadelphia County for consumption.

This is a story about what happens when a corporation that markets itself as an industry leader in “safety, health, and environment” as its “first value” rushes a corroded 74-year-old tank back into service without ensuring it is safe to operate. It is a story about a family whose children played in a basement contaminated with benzene while the company knew and said nothing. It is a story about gift cards distributed under the guise of goodwill while an environmental catastrophe unfolded in silence.

The Non-Financial Ledger: What the Numbers Cannot Measure

Brian and Michelle Mielnik own and reside at 5917 Chichester Avenue in Aston, Pennsylvania, together with their four minor children. Their property is one of nine homes located along the fence line of the Chelsea Tank Farm. It is one of the closest residences to Tank 708.

Since March 2025, the Mielniks watched vegetation on their property die without knowing the reason. Throughout the spring and summer of 2025, they occasionally smelled gasoline from their property. They observed bright lighting and loud activity at the Tank Farm behind their home during this period. They did not know what was happening.

In August 2025, Monroe Energy’s representatives began appearing at their doorstep on a weekly basis to distribute gift cards, apologizing for “the use of light plants and other equipment” related to “maintenance work.” The Mielniks accepted the cards and thought nothing more of it. They trusted that if something dangerous were happening, someone would tell them.

No one did.

It was not until December 5, 2025—nine months after the leak began—that the Mielniks received a letter from Monroe Energy stating that there had been “an issue” at the Tank Farm. Even then, the letter minimized the contamination and provided no indication that their property or their family might be at risk.

April 30, 2026: The Day Everything Changed

On April 30, 2026—more than a year after the leak began—Monroe Energy’s agents finally began collecting sub-slab soil gas and indoor air samples from the Mielniks’ residence. When the agents arrived, they verbally represented to the Mielniks that the testing results showed “only a small increase in VOCs near the basement” and that this was “nothing to worry about.”

This was false.

In reality, the testing results showed that benzene and VOC levels inside the Mielniks’ home were dangerously high. Monroe Energy withheld those results—purportedly to “review the results with their team”—while the Mielnik family, including their four children, continued to live in and breathe the contaminated air.

May 1, 2026: The Evacuation

The next day, May 1, 2026, Monroe Energy asked the Mielniks to meet at their home “to go over the test results.” That afternoon, a crowd of Monroe Energy personnel descended on the Mielnik property in black SUVs. They swept through the home with handheld meters that registered benzene at concentrations even higher than those previously found. They caulked openings. They set up temporary fans. They told the family they had to leave immediately.

The Mielnik children arrived home from school to a house full of strangers in hazmat-adjacent gear. Plaintiff Brian Mielnik was forced to ask his children to hurriedly pack some clothes and to wait outside while he held back his own fear of what was unfolding. Plaintiff Michelle Mielnik, who had no notice of the meeting, returned home briefly before her afternoon softball coaching obligations and was blindsided by the driveway full of black SUVs and the throng of people overrunning her home.

Monroe Energy instructed the Mielniks to relocate to temporary housing. Air filtration units were delivered to the residence. By then, the Mielniks and their children had already been breathing those dangerous levels of benzene and other VOCs for over a year.

The Blood Tests

After being displaced from their residence, the Mielniks underwent blood testing. Results showed elevated toxin levels consistent with VOC and benzene exposure:

• The Mielniks’ 16-year-old child had elevated alkaline phosphatase levels, which can be associated with exposure to VOCs.
• Two other family members had elevated phenol levels, which can be associated with benzene exposure.

The reviewing physician advised repeat blood testing every three months for one year for five family members, and every six weeks for the child with elevated alkaline phosphatase levels. The physician also informed the Mielniks that because the blood testing was performed several days after the family had already vacated the residence, any benzene exposure that had occurred while they lived there would not be reflected in the results—even if exposure had occurred.

The Mielniks now face a lifetime of medical monitoring, knowing that the carcinogens their children were exposed to may not manifest as disease for years or even decades.

The Contamination in the Ground Beneath Their Home

In April 2026, Monroe Energy installed two groundwater monitoring wells on the Mielnik property. Testing revealed:

• 1.7 feet of free-floating gasoline in monitoring well MW-A1
• 2.1 feet of free-floating gasoline in monitoring well MW-A2

A soil gas sample taken 30 feet from the Mielniks’ residence—under the ground upon which their young children play—tested positive for cyclohexane at 713,000 µg/m³ and n-hexane at 4,300,000 µg/m³, exceeding applicable PADEP screening values.

Sub-slab soil gas monitoring points in two basements of neighborhood residents produced exceedances of PADEP Residential Sub-Slab Soil Gas Vapor Intrusion Screening Values. At the Mielniks’ residence, samples collected on April 30, 2026 detected:

• Benzene at 671 J µg/m³
• Cyclohexane at 571,000 µg/m³
• N-hexane at 500,000 µg/m³

At a nearby residence, samples collected May 4, 2026 detected:

• Benzene at 2,880 J µg/m³
• Cyclohexane at 152,000 µg/m³
• N-hexane at 230,000 µg/m³

Indoor air testing at the Mielniks’ residence detected benzene at 0.987 µg/m³ and n-hexane at 811 µg/m³. Even after a vapor-intrusion mitigation system was installed, benzene, ethylbenzene, and naphthalene persisted in the indoor air. A nearby residence showed similar contamination, with benzene at 3.93 µg/m³.

Monroe Energy has refused to provide the Mielniks with information about monitoring well test results from neighboring properties, claiming that doing so would violate the privacy of those neighbors. As a result, the Mielniks are left in the dark as to the extent of the contamination surrounding them—including in the air, water, and soil to which they are also at risk of exposure.

“Plaintiffs love their home. They thought it would be their forever home, where they would raise their children and grow old together. Unfortunately, Defendants’ Leak has turned Plaintiffs’ idyllic forever home into the site of an environmental catastrophe.”

The Vapor-Intrusion Mitigation System

Because of the air contamination caused by the leak, Monroe Energy installed a vapor-intrusion mitigation system in the basement of the Mielniks’ residence. The system is extremely loud and operates continuously, comparable to a vacuum running 24 hours a day, seven days a week.

Before learning of the contamination, the Mielniks’ children played in the basement. The space served as a gym, workout area, and laundry room. Because of the noise from the mitigation system—and the fear and anxiety caused by worrying that their indoor air could become more contaminated at any moment if the system fails or if the plume continues to move—the Mielniks are no longer able to enjoy or use their basement. They have stopped allowing their children to play there, concerned for their children’s health and worried they might accidentally turn off the mitigation system.

The Mielniks also now limit their own use of the basement, venturing down only to do laundry.

The Property That Will Never Sell

Since the revelation of the leak and subsequent confirmation of contamination, the Mielniks have experienced profound anxiety, fear, emotional distress, and uncertainty regarding the safety of their home, their health, and the wellbeing of their family. They live with the persistent fear that the exposures they have already had to the VOCs released by Monroe Energy’s leak will cause severe and potentially life-long consequences to them or their minor children.

The property itself has been rendered valueless. Who would purchase a home in a remediation zone, where the air, water, and soil contain dangerous and toxic chemicals? Who would ever want to live so close to Monroe Energy’s Tank Farm after Monroe Energy—despite years of advertising themselves as industry leaders in safety and environmental stewardship—allowed such a catastrophic release to occur and go unnoticed for most of a year?

The Mielniks are now trapped. They cannot sell. They cannot leave. And they cannot trust that the home they thought would be their forever home will not kill them.

Societal Impact Mapping: The Poisoning of Aston

Environmental Degradation

The leak from Tank 708 resulted in a significant subsurface contamination plume that has migrated off the Tank Farm and into the surrounding residential neighborhood. Monroe Energy’s own investigation has confirmed gasoline-related impacts to soil, air, and groundwater across the affected area.

As of July 7, 2026, 110 groundwater monitoring wells have been installed across the Tank Farm and surrounding neighborhood. Of those, 50 wells have been found to contain measurable light non-aqueous phase liquid (LNAPL)—visible free-floating gasoline—including wells on residential properties adjoining the Tank Farm.

Monroe Energy conducted low-flow groundwater sampling for 53 monitoring wells that did not contain LNAPL. Of those 53, petroleum-related contaminants—including benzene and other gasoline-related VOCs—were found in 20 monitoring wells at concentrations above the applicable Act 2 Groundwater Medium-Specific Concentrations (MSCs) and/or Vapor Intrusion Screening Values for Groundwater (SVs).

Four private drinking water wells within 1,000 feet of the Tank Farm’s western boundary have confirmed detections of gasoline-related volatile organic compounds, including BTEX compounds.

Exterior near-source soil gas sampling at the Mielniks’ property detected cyclohexane at 713,000 µg/m³ and n-hexane at 4,300,000 µg/m³, exceeding applicable PADEP screening values. Ambient air samples collected from locations along the Tank Farm’s perimeter fence line on May 29, 2026 showed levels of naphthalene and isopropanol above EPA risk-based chronic screening levels.

As of July 7, 2026, only 69,464 gallons of LNAPL have been recovered—a mere fraction of the 378,000 gallons that Monroe Energy admits to having released. The plume has not been fully delineated, and new contamination continues to be encountered in recently installed monitoring wells on offsite residential properties, despite ongoing recovery efforts.

All of the evidence available suggests that the contamination plume is immense and is continuing to migrate. As it migrates, more and more residents will be directly exposed to the toxic chemicals released by Monroe Energy’s leak.

Public Health

The gasoline released by the leak contains highly toxic and carcinogenic VOCs and chemicals, including:

• Benzene: A known human carcinogen according to both the International Agency for Research on Cancer (IARC) and the U.S. Environmental Protection Agency (EPA). Benzene exposure can result in cancer, disruption of hematopoiesis (the body’s production of blood), suppression of the immune system, and skeletal and neurodevelopmental defects.
• BTEX compounds (benzene, toluene, ethylbenzene, and xylenes): Volatile aromatic hydrocarbons commonly found in gasoline and petroleum products. BTEX compounds are often primary contaminants of concern in the remediation of oil or gasoline spills due to their high volatility, mobility, and toxicity.
• N-hexane: A highly volatile neurotoxic chemical derived from crude oil. Short-term exposure can impact the central nervous system; longer-term exposures are associated with polyneuropathy, muscular weakness, vision impairments, and fatigue.
• Cyclohexane: A highly volatile chemical that can cause severe respiratory and pulmonary symptoms, including pneumonitis. It can break down the fats in skin tissue, causing dry and cracked skin and even burns with repeated or prolonged skin contact.
• Isopropanol, naphthalene, and ethylbenzene: Additional toxic compounds detected in air, soil, and groundwater samples.

Short-term exposure to BTEX compounds can cause nausea, vomiting, headaches, dizziness, rashes, and eye and throat irritation. Long-term exposure can have serious health consequences, including anemia, compromised immune system, bone marrow damage, irreversible hearing loss, liver and kidney damage, pregnancy and fertility complications, and leukemia and other forms of cancer.

The chemicals released from Tank 708 are associated with serious diseases that have long latency periods and may not manifest in exposed individuals for years or even decades. Residents in the surrounding communities will have to closely monitor their health, potentially indefinitely. They have experienced, and will continue to experience, the accompanying fear and anxiety that comes from not being able to trust the safety of the water they drink or the air that they breathe.

Economic Inequality

The release has devastated property values in the area. The contamination is public and will impair the value of all properties in the area and the market interest in what were once desirable properties for the foreseeable future.

Families like the Mielniks—who invested their life savings into homes they believed would be their forever homes—are now trapped. They cannot sell contaminated properties. They cannot afford to abandon their mortgages. And they have suffered extreme diminution to their property values, thus creating additional economic damages and losses that substantially affect their financial security and cause additional stress and anxiety.

Monroe Energy initially promised to “restore and remediate” the impacted properties. At a public meeting on February 4, 2026, Monroe Energy’s COO stated: “We own this problem,” and promised to “make things right.” Later in the same meeting, however, Monroe Energy walked back that promise, stating that the company would clean up only “to the standards that [PADEP] is enforcing.”

This is the language of a corporation that has already decided how little it can get away with paying.