High levels of four toxic chemicals have been found leaking into groundwater surrounding Bountiful's municipal dump and contaminating waters of the Great Salt Lake.
A private consulting firm told the City Council Wednesday night that ground-water analyzed from test wells in and around the Bountiful Sanitary Landfill has high levels of toxic lead, selenium, benzene and vinyl chloride.Control of the landfill, located in West Bountiful and formerly called Bay Area Refuse Disposal Landfill, changed from seven South Davis County cities to Bountiful when Bountiful refused to join a special service district that constructed a garbage-burning plant in Layton.
Steven Johnson, hydrogeologist with James. M. Montgomery Consulting Engineers Inc., told the council that the levels of lead and selenium were only slightly greater than those allowed by federal drinking water standards. Levels of benzene and vinyl chloride, however, "totally demolished" the standards, he said.
"Water is escaping from the landfill at about three gallons per minute . . . This is no way to run a landfill," Johnson said with a little humor noting that a much greater amount of contaminated water was expected to be escaping.
While officials have known that chemicals have been leaking from the 25-year-old landfill for years, this is the first real measurement of its effects on the environment. Aquifers in the area are not connected to any residential water use.
Good news from the tests showed that aquifer pressure on the opposite side of the landfill from the lake is preventing the contaminated water or landfill leachate from moving in that direction and is keeping water out of refuse.
"A significantly higher groundwater pressure minimizes chance that it comes in contact with refuse," Johnson said.
However, rainfall and surface moisture have created a bubble of contaminated water within the landfill are that is siphoned into nearby Barton Creek. Also, a layer of clay that sits about 10 feet under the landfill has diverted water directly into the lake rather than contaminating deeper aquifers, Johnson said.
"It minimizes the flow of contaminated water downward because it acts as a liner," he said.
To stop the leachate leaking in anticipation of new EPA landfill standards, Montgomery engineer Bob Ramsey is recommending the city consider building a slurry wall between the landfill and the lake. Ramsey has also suggested that Barton Creek be lined or diverted, that a clay cover be installed over the site to keep rain out of buried trash and install a dewatering system that pumps the leachate away from groundwater.
Such remediation projects, however, are likely to be held up because of funding. A $1.6 million cleanup fund budgeted by the former landfill board is being held up by legal negotiations between member cities of the former special service district that governed the landfill. Those affected are Farmington, Centerville, West Bountiful, Wood Cross and North Salt Lake.
A major sticking point is whether or not the cities will continue to be liable for environmental problems caused by the landfill. About 110 acres of land contain buried trash.
For the past 2 1/2 years, Bountiful has been stacking garbage on top of the ground and covering it rather than burying it. The process, said City Manager Tom Hardy, helps prevent the creation of more ground water problems. The city hopes to continue to use the landfill for another 20 to 30 years.