Tensions among agencies involved in the cleanup of a massive gasoline pipeline spill on tribal lands south of Durango bubbled up Tuesday during a public forum.
La Plata County hosted the forum – the first of its kind – in which representatives from Enterprise Products, the Southern Ute Indian Tribe and a Colorado agency clashed over the estimated volume of the fuel leak and presented conflicting interpretations about whether ground contamination is on the move.
The discussion also hinted at behind-the-scenes disagreements about monitoring strategies, including the adequacy of wells installed near the southern edge of the plume.
In 2024, a rupture occurred in the 18.5-mile section of Houston-based Enterprise Products Mid-America Pipeline that runs across the SUIT reservation. It sent tens of thousands of gallons of fuel spilling into the environment and resulted in multiple families being displaced from their homes.
Cleanup efforts have been ongoing, with SUIT, the Colorado Department of Public Health and Environment and the Environmental Protection Agency working alongside Enterprise to aid and monitor the remediation work.
The forum on Tuesday marked the first time since the spill Enterprise made a public appearance to answer questions from the broader La Plata County population. The company has been conducting meetings among homeowners affected by the spill.
It was also the first time the state representative and tribal representatives were publicly available to answer questions.
The Board of County Commissioners moderated the question-and-answer session that featured questions submitted in advance to the county and were edited for clarity before being presented. The questions addressed public health, groundwater contamination, private wells, agricultural and environmental impacts, cleanup efforts and the long-term safety of the pipeline.
The central dispute remains how much gasoline was released into the environment.
The tribe estimates the spill exceeded 200,000 gallons, while Enterprise stands by the estimated 97,000 gallons.
The tribe commissioned its own analysis of the spill using consultants hired to independently evaluate the release and cleanup effort.
The state will not conduct an independent spill-volume analysis, despite uncertainty surrounding the estimate, said Patrick Cummins, the director of environmental health and protection for CDPHE.
The state has asked Enterprise to provide a substantive response to the tribe’s consultant report by July 31.
Federal regulators recognize the possibility that the actual spill volume exceeded 97,000 gallons. The Environmental Protection Agency reviewed the competing estimates and suggested the true volume may fall somewhere between Enterprise’s estimate and the tribe’s estimate of roughly 207,000 gallons, Cummins said.
Enterprise officials maintained that their calculation is the most accurate and argued that the precise volume released is less important than the ongoing remediation effort.
The company’s estimate is based on metered product volumes entering and leaving the pipeline, combined with operational data from the time of the release. Enterprise argued that those measurements are more reliable than estimates derived from soil sampling and groundwater data, the methodology used by the tribe's consultant.
“I kind of liken it to if I’ve got a 5-gallon can of diesel and I’m carrying it around, I drop it off and I spill it on the ground,” said Graham Bacon, Enterprise’s chief operating officer. “Some scientist comes in and picks out some pieces of dirt, runs it in the lab and tells me I have a 10-gallon spill, but I knew I only had a 5-gallon bucket.”
Mark Hutson, environmental program director for SUIT, pushed back on the analogy. He said Enterprise’s estimate has increased several times since the spill was discovered – from about 19,000 gallons to 37,000 gallons and later to roughly 97,000 gallons – changes he said occurred largely at the behest of the tribe.
Hutson also argued that the tribe’s consultants employed a more sophisticated methodology than the analogy suggested.
“I’d like to give Fern (a consulted hydrogeologist) just a little bit more time to explain her analogy, and that’s the scientific method,” Hutson said.
The method involved three date sets; a large soil data set with 1,300 samples, and one of the largest soil sampling efforts HRS has ever conducted; analysis of the thickness of the free floating gasoline in wells, and visible staining of soils and other field observations as additional evidence of where gasoline has migrated.
Those three data sets were then combined to produce a three‑dimensional shape in the ground that represents where gasoline exists and in what concentration range.
Regarding the migration of the gasoline plume, SUIT consultants estimated the plume is moving about 8 to 10 feet per day and pointed to recent low-level detections south of the main plume as evidence, although Cummins said CDPHE disagreed.
Current data shows a slower, more complex picture influenced by seasonal irrigation and groundwater levels, he said.
Still, Hutson urged the public to consider findings from independent consultants hired by the tribe. He noted that he wants at least two full irrigation and groundwater cycles before drawing conclusions about plume behavior.
Enterprise said the main plume has largely stalled within an irrigated field north of a “sentinel” well line, though low‑level detections to the south are being tracked and additional treatment systems are in place if needed.
Attendees also fielded questions regarding impacts on agriculture and surface water. Enterprise said benzene – a highly flammable organic compound and known carcinogen present in crude oil – has not been detected in the Mason ditch.
The Animas River close to the site of the initial leak remains clear of any gasoline related contaminants.
The cleanup timeline remains unclear, although Enterprise executives said they will continue work “until it’s cleaned up.” The company is prepared to spend $100 million on response and remediation.
jbowman@durangoherald.com
