Perhaps the most well-known example of ground water
contamination in the lower Portneuf Valley is the trichloroethylene (TCE) plume in the
southern valley and in the vicinity of the old County landfill. A similar chlorinated
solvent, perchloroethylene (PCE), is the cause of Chubbuck's water quality problems. Both
originate from disposal on the land surface, and find their way to the water table where
they are then carried by the movement of ground water.
Due to the rapid rate of ground
water flow in the southern valley aquifer (up to 50 feet per day), the TCE plume at one
time was advancing and affecting water quality in downstream wells at the rate of a mile
per year. Several wells have been closed because their concentrations of TCE exceed safe
limits; some remain closed, others have reopened. The plume still extends the length of
the southern valley, but remediation is underway. |