CLINTON — Thanks to constant vigilance and monitoring, water contamination — the result of years of improper disposal of chemicals from Hill Air Force Base — is slowly being done away with, says a representative from Hill.
At a recent city council meeting, Jarrod Case, HAFB representative from the Environmental Restoration Branch of the 75th Civil Engineer Group, presented an annual update on the disposal efforts regarding a groundwater contamination plume.
Underground water contamination has been a problem for a number of communities surrounding the base for nearly 30 years, he said.
Actually, the contamination has been going on for many decades, but it wasn’t until 1987 that groundwater contamination was discovered in Clinton.
“Since its beginning, HAFB has been used as an aircraft maintenance facility. When World War II ended in 1945, Hill processed planes for storage, but aircraft maintenance once again began with the Korean War in the early 1950s and again during the Vietnam War in the 1960s and 1970s,” Case said.
Aircraft maintenance is a messy job, he said.
Engines and other parts were cleaned and degreased, paint was removed and reapplied to aircraft, and anti-corrosion coatings were removed and reapplied to airframes and parts. These processes used thousands of gallons of chemicals, Case said.
Back then, unlike today when the use and disposal of chemicals is closely tracked and regulated, there were no regulations for the disposal of chemicals, so the chemicals were usually disposed of in pits and trenches.
No one at that time knew how this would affect the environment and future generations, Case said.
Since then, he said, two contamination plumes have been discovered in Clinton, and the primary chemical found in them is trichloroethene, or TCE.
The northern plume is from HAFB to approximately 1300 West in Clinton, and the southern plume originates from the Tooele Army Rail Shop, or TARS, on HAFB to about 900 West.
Case said the two systems in place to treat the TARS plume have caused the plume to shrink. Contamination levels are naturally declining as anticipated and are carefully monitored to ensure continued progress.
It is important to note that all military bases have this problem, Case also said.
It’s also important for the public to know that the base contamination does not affect local drinking water supplies, he said.
Clinton’s drinking water comes from deeper aquifers: the Sunset aquifer, which is 250 to 400 feet belowground, the Delta aquifer, which is 500 to 700 feet belowground, and mountain reservoirs.
It does not come from the contaminated shallow groundwater aquifer.
Case added that maximum depth of TCE contamination in the groundwater ranges from 35 to 85 feet below the ground surface depending on where you are. (The plume is deeper on the base and becomes more shallow as you move away from the base into Sunset and Clinton.)
In addition, the deep drinking water aquifers are separated from the shallow contaminated groundwater by numerous clay layers that prevent contamination from moving down.
Because chemicals can evaporate and move into homes from the groundwater below, Case said, the Air Force provides free air sampling and, if necessary, free vapor removal systems.
Anyone who wants more information or needs testing may call Barbara Fisher, HAFB representative in Public Affairs, at 801-775-3652.
Councilwoman Joanne Hansen said she had the sampling done and was impressed with the professionalism, care and concern shown by those who came to her home to perform the test.
Case said the Air Force will complete a five-year review this year, as required by environmental cleanup laws. This review is done by a third party to verify that treatment systems and ongoing studies are protecting human health and the environment, and are meeting cleanup goals.
The public will have the opportunity to participate in this review later this year.