CHIBA -- A plot of land where a condominium is to be built in Inage Ward, Chiba Prefecture, has highly cancerous hexavalent chromium concentrations 2,400 times the environmental standard set by the government, it was learned Aug. 19.

The Environment Agency acknowledged that the chemical concentrations were the worst on record since standards for soil contamination were set in 1991.

According to the Chiba Municipal Government, Maruyama Works Ltd., an agricultural chemical spray maker, had been operating on the site since April.

The company had a plating plant at the factory site using hexavalent chromium from 1960 through 1986, local authorities said.

In compliance with the municipal government's instruction, the company shipped about 3,500 tons of contaminated soil away from the site. Maruyama Works plans to dig out more earth until it reaches a layer where hexavalent chromium levels fall below the environmental standard, the local authorities said.

The company conducted contamination checks throughout the 20,000-sq. meter site starting in April after it moved the plant off the site. It detected 120 mg of hexavalent chromium, or 2,400 times the government standard, from earth dug from 3.5 meters below the 500-sq. meter plating factory site, the authorities said.

The spot is where hexavalent chromium waste water was formerly disposed. The company believes the waste leaked from a disposal tank, the authorities said. The company also acknowledged that hexavalent chromium concentration levels near the factory's waste water outlet were also about 40 times above the environmental standard, they said.

The Chiba Municipal Government tested water samples from about 60 wells around the factory site to check if groundwater had been affected, but no abnormality was detected, they claimed.