Diamond Alkali was largely responsible for contamination leading to the creation of a Superfund Site in the Ironbound section of Newark, New Jersey.
Between 1951 and 1969, Diamond Alkali in Newark produced approximately 700,000 US gallons (2,600,000 L; 580,000 imp gal) of the herbicide Agent Orange.
[3] In 1986, the Diamond Shamrock Corporation agreed to pay $150,000 for a canvas tarpaulin to cover 3 acres (12,000 m2) of the contaminated area.
[9] The Diamond Shamrock Corp. (Painesville Works) site is an 1,100-acre former chemical manufacturing facility in Lake County, Ohio.
However, the presence of chromate wastes in the landfill cell made it necessary to continue long term monitoring, inspection, and reporting for this area.
The closure consisted of installing sheet piling along the Grand River and an impermeable clay cap placed over all the waste areas.
[13] In 2006, the potentially responsible parties upgraded and repaired the clay cap at Operable Unit #16, and improved some of the drainage at and around the site.