Salina State officials have been scrambling to head off an underground plume of contaminated groundwater inching toward one of the city's public water wells.
City leaders recently discovered the plume originating from the site of a company that fumigated area grain elevators 35 years ago.
Martha Tasker, Salina's utilities director, said their tests showed none of the contamination had gotten into the city's wells.
The Kansas Department of Health and Environment, beginning Oct. 24, plans to start removing about 180 cubic yards of contaminated soil. A large boring machine will dig a series of holes five feet wide and 40 feet deep. The dirt will then be carted off and treated.
"We are going to eliminate as much of the source of the contamination as we possibly can," said Ricky Brunetti, district environmental administrator.
Removing the dirt will take about a week, and then state environmental officials will install equipment to remove contamination from the groundwater.
Tests indicate the plume contains dangerous levels of two chemicals, carbon tetrachloride and 1,2, dichloro-ethane, also called DCA. Both chemicals are often used in grain fumigants and pesticide.
State officials said the safe limit for carbon tetrachloride in drinking water is five parts per billion but that the plume contains 550,000 parts per billion. As for DCA, the safe level is 100 parts per billion but the plume contains 1.7 million parts per billion.
A former employee of the fumigant company told investigators that thousands of gallons of fumigant disappeared overnight from the plant in 1969 or 1970. He said it was believed to have leaked from an aboveground storage tank on the site.
Brunetti said the state will pay for the cleanup, but he said investigators were trying to find people responsible for the leak so they could contribute to the cost.
Salina has become quite knowledgeable on dealing with contaminated groundwater. The city discovered in the early 1990s that a huge plume of contamination from the former Schilling Air Force Base was slowly moving toward downtown. City officials also found that groundwater under downtown itself was contaminated, probably from a combination of dry cleaners, gas stations, electronics manufacturers and other businesses.
The state now requires the city to treat all groundwater it pumps from its well fields to its water plant, which cleans and delivers about 2.5 billion gallons of water a year.