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Sep-20-2009 18:25printcomments

El Toro Marines Question TCE Usage

EPA reported that Trichloroethylene (TCE) was discontinued at MCAS El Toro in the mid-1970s. Marine veterans dispute this story.

The air traffic control tower at El Toro
The air traffic control tower at the now-closed El Toro Marine Corps Air Station in Orange County, California.
Photos by Bonnie King, Sean King and Tim King

(IRVINE, Calif.) - Reports from the 1980s and 90s indicate usage of TCE, even though the “official” word is that it was not used. 1,1,1-TRICHLOROETHANE or methyl chloroform or TCA, a less toxic chemical solvent, was also used at El Toro.

Who’s telling the truth about TCE usage at former MCAS El Toro? The practice of using TCE at former MCAS El Toro was reported to be discontinued by the Environmental Protection Agency in the mid-1970s. Emails from Marine veterans who were stationed at El Toro in the 1980s and 1990s question the veracity of the EPA report.

TCE is a carcinogen and was widely used by the military and industry for decades without regard for sound environmental practices. A TCE plume now spreads from El Toro into Orange County for miles.

El Toro was placed on the National Priority List (EPA Superfund) and officially closed in July 1999. Reports from Marines on the base in the 1980s and 1990s indicate use of TCE, even though the “official” word is that it was not used.

An email from a Senior Staff NCO challenged the EPA official story: "You say that these chemicals were only used until the mid 1970's but I know for a fact that they were used up until the early 1990's. How do I know because we used them OFTEN.”

“As you said they were a degreaser and an outstanding one at that. They were also used for hydraulic contamination testing and keeping hydraulic components and equipment clean. When I was with VMA(AW)-121 and MALS-11, we would use the stuff daily (1-5 gallons).”

“I think the hangers that you are referring to are the KC-130 hangers on the west end of the base. I do know of a Marine that spent most of his career in that hanger and died of cancer soon after retiring (months), the VA/USMC claimed not military related.”

“We took up a big collection in the squadron/KC-130 community to help his family pay for medical bills.”

TCE was used to degrease motor vehicles on base in the 1980s. An El Toro Marine reported that: “I was stationed at El Toro from 1987-1989 with MWSS-373 support squadron. We Marines used a lot of degreaser to clean the military vehicles. I lived on the base, need to get on the list to find out the symptoms of TCE exposure. MWSS-37 was located very close to where I worked. My wife was there from 86-90 has had numerous health issues including unexplained headaches and sleep disorder as well as neurological including MS.”

Although officially banned on base, TCE was "kept out of sight" and used as a degreaser according to this Marine: “I was an enlisted ordnance man with VMA - 214 Black Sheep Squadron from 1985-88. I loaded heavy munitions on the A4-M Sky Hawk and when these aircraft would return after dropping the bombs, we were required to break down and clean either the 'MER' or 'TER' ejection racks. Part of this cleaning process consisted of "secretly" soaking certain parts in a solvent that came in 5 gallon green cans with yellow lettering stating that it was TCE."

He says he was told that they were not to get caught using this solvent because it was not an authorized cleaning agent, only soap and water were officially authorized.

"The 5 gallon cans were always kept out of sight until I poured them into a 55 gallon drum that was cut in half, length ways and mounted in a welded frame. The parts would stay in the solvent for 24 hours then I had to remove them by hand and place them into 5 gallon buckets filled with soap and water, take them into the hangar and scrub them. I cannot count the times that I did that process but I spent many hours with my arms, elbow deep in that solvent. I remember being amazed at how quickly the solvent would evaporate off my arms when I brought them out of the soaking drum.”

From another El Toro Marine, “I am suffering from Idiopathic Pulmonary Fibrosis and was stationed at El Toro from 1981 to 1984. I worked with in Hanger 2, H&MS-13. We used the chemicals in question on a regular basis to clean the parts of the aircraft weaponry and other aircraft parts. There were no warning signs that the chemicals used were dangerous nor were there PPE to protect us at that time. The doctors are still trying to determine the extent of the disease. I hope that I will be able to live another five years.”

EPA conducted on-site reviews with active and retired personnel in July 1994. Among the subject discussed were the types of chemicals used in operations.

EPA reported that: “The VOCs at Site 24 may have come from solvents containing TCE and PCE that were used at Site 24 until approximately 1975 [emphasis added].”

EPA Site 24 was the primary source for the TCE plume spreading off base into Orange County. Marine transport aircraft--heavy users for organic solvents--were position in this area for decades.

How can you explain the significant differences in dates in TCE usage? EPA relied on interviews of military and civilian workers on the base. El Toro kept no documentation of TCE usage or other records to rely on. An interview of military and civilian personnel makes sense, provided the right questions are asked. Memory is tricky, especially with the passage of time. However, it’s hard to believe that the “collective memories” of professionals were off by a magnitude of twenty years.

One obvious question not asked by EPA was, “If El Toro stopped using TCE in the mid-1970s, then what was the substitute solvent?” Soap and water or SOS pads are not going to get the job done.

There’s no information in the “EPA Final Record of Decision - OU-2A Site 24, Former MCAS El Toro,” dated April 2006, that anyone asked this question. Was there a substitute for TCE?

In fact, the answer is “yes.” EPA’s list of contaminants of concern (CoC) for El Toro showed that 1,1,1-trichloroethane or TCA was listed as a CoC. CoCs are chemical substances found at the site that the EPA has determined pose an unacceptable risk to human health or the environment.

A chemical consultant advised that TCA was widely used as a substitute for TCE in the 80s since it was not banned by EPA and had a “lower toxic profile” than TCE.

As it turned out TCA was later banned by the 1987 Montreal Protocol because it was found to deplete the ozone layer.

TCA was reported by EPA to be in the groundwater throughout the base and in the soil and groundwater under Site 24, the source area for the TCE plume spreading into Orange County and the area were Marine C-130s transports (4 engine turbo prop aircraft) were maintained.

So evidence indicates that both TCE and TCA were used on the base.

I can’t explain why TCE would continue to be used when TCA, a “less toxic” substitute, was available. TCE had a reputation for being an excellent cleaning solvent.

The Marines who worked on the base in the 80s and 90s were intimately familiar with operations. TCE or TCA may just be a case of pick your poison. As a Marine veteran, I put my money on the Marines who worked on aircraft at El Toro in 80s and 90s. Others may have a different opinion.

Are Marine veterans confusing TCE with TCA? I seriously doubt that. The drums were clearly marked. It was OK to use TCA at one point, but not TCE. When TCE was used, it had to be hidden from sight. You don’t forget those kinds of things.

The really sad part of this is that Marines who are seriously ill from cancer and other medical conditions linked to TCE exposure at El Toro, now have to wage battle with the VA to obtain disability compensation. Unfortunately, this is not a level playing field and many will lose the fight.

A 1993 El Toro photo (see below) shows C-130s parked on the MWSG-37 tarmac. These aircraft had to be maintained, which meant that parts had to be degreased.

El Toro Marine veterans with first hand knowledge of TCE usage on the base are encouraged to email me at: .

Here is a list of the articles that have been generated on the contamination of the former Marine Base at El Toro and at Camp Lejeune, North Carolina:

Follow this link to all of our stories about the Marine Corps and TCE

Bob O’Dowd is a former U.S. Marine with thirty years of experience on the east coast as an auditor, accountant, and financial manager with the Federal government. Half of that time was spent with the Defense Logistics Agency in Philadelphia. Originally from Pennsylvania, he enlisted in the Marine Corps at age 19, served in the 1st, 3rd, and 4th Marine Aircraft Wings in 52 months of active duty in the 1960s. A graduate of Temple University, Bob has been married to Grace for 31 years. He is the father of two adult children and the grandfather of two boys. Bob has a blog site on former MCAS El Toro at This subject is where Bob intersected with Bob served in the exact same Marine Aviation Squadron that Salem-News founder Tim King served in, twenty years earlier. With their combined on-site knowledge and research ability, Bob and Tim and a handful of other ex-Marines, have put the contamination of MCAS El Toro on the map. The base is highly contaminated with TCE, trichloroethelyne. You can email Bob O’Dowd, Environmental and Military Reporter, at this address:

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Timothy October 25, 2019 10:28 am (Pacific time)

Just read this. I wonder if some confusion exists between TCE and TCTFE. As a Marine trained in El Toro but stationed in Cherry Point from 1992-1996, I’ve heard of TCTFE referred to as “Trike” (TCE). They both are cleaning solvents, both came in similar 5 gallon containers. We used TCTFE for patch tests on hydraulic systems and for degreasing. TCTFE was also later phased out (by P-D-680 which itself was largely phased out) but we had some limited quantities that we held on to for a couple of years. My personal experience would have me believe that TCE was phased out and confused with TCTFE.

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