The cleanup of an old dump found during roadwork along Elm Creek Park Reserve received the largest of 20 cleanup grants funded by the Hennepin County Board.

The Goose Lake Road dump project was awarded $735,000 of the $2.4 million in Environmental Response Fund grants approved by the board in late January.

The money will be used to excavate and remove dump material containing four metals: mercury, lead, arsenic and selenium, said John Evans, a senior environmentalist for the county.

The century-old dump was found under a portion of a mile stretch of Goose Lake Road that is being rebuilt north of 109th Street along the Champlin-Dayton border.

Mercury is the primary concern because tests found levels considered unsafe, though not hazardous, by the state Pollution Control Agency, Evans said.

Debris with the mercury at that level is barred from Minnesota landfills, so it will be sent to an Iowa landfill.

Tests of the other three metals found some at levels not acceptable for property used for residential or recreational purposes, he noted. Most of the dump had lower-level contamination that can be accepted by Minnesota landfills, Evans said. It's not known yet if any contaminants leached into nearby Goose Lake, he added.

Last year workers unearthed a half-dozen vehicle batteries and brake parts, glass bottles with stoppers, roofing debris and other junk in the landfill, which was recovered with dirt until cleanup work resumes in May.

Three other projects received large grants:

• Methane venting from a dump under an unnamed Excelsior park near Oak Street and Beehrle Avenue: $303,600.

• Removal of contaminated soil for East Bank Mills, an office and residential development at 300 2nd St. SE. in Minneapolis: $283,800.

• Removal of petroleum and other contaminants to redevelop a 14-acre Wayzata Center shopping mall near Lake Street and Superior Boulevard: $249,900.

The response grants, funded by a county mortgage registry and deed tax, pay for assessment and cleanup of polluted sites. Priority is given to projects involving green space, affordable or moderately priced housing, and economic development.

Jim Adams • 612-673-7658