Toxic organic compounds and heavy metals dumped at the site have percolated into the ground water and leached into lakes and streams in the surrounding area.
During the period from 1958 until 1971, the landfill accepted 46,000 barrels of chemicals, containing approximately 2.7 million US gallons (10,000 m3) of industrial waste, that were placed in trenches that had been excavated in the gravel pit.
[4] A follow-up study by medical investigators released in 1997 reviewing details of 9,000 children born to parents living near the dump site found clear evidence of a link to the toxic chemicals and a significant drop in birth weight and a risk of pre-term delivery that was twice as high as normal.
The study also found that after the dump was closed and cleanup began, birth weights increased until they were higher than those from surrounding areas in the most recent data.
[3] In March 1994, Rohm and Haas reached a settlement with the United States Department of Justice under which the firm would address its liability for the materials it dumped there by spending an estimated $50 million to clean up the landfill site.
[5] The cleanup project [6] was estimated to have run in excess of $100 million by 1995, with the majority of costs paid by the companies that had material dumped at the site.
[7] About 90,000 tons of contaminated soil was removed from the off-site areas temporarily stored at the site of a former stock car race track in Pitman and later sent to a properly lined landfill.