About the Site

The Diamond Shamrock Chemical Company began operations in 1912 under the name Diamond Alkali. Over the facility’s 65-year operation, the company produced chemicals and other products including: soda ash, caustic soda, coke, sodium bicarbonate, cement, chlorine, chlorinated hydrocarbons, sodium dichromate, chromic acid, magnesium, and chlorowax. These products were either sold for profit or utilized by Diamond Alkali/Diamond Shamrock in its manufacturing processes.


Hazardous and solid wastes were disposed of on site at various locations. Soda ash process waste was disposed of in large waste lakes (soup ponds). This liquid waste was allowed to evaporate leaving behind a solid white residue. As of November 1995, the residue could still be seen on the surface of one of the former waste lakes located on the south side of the Grand River. Wastes disposed of in these lakes mostly included calcium chloride, calcium carbonate, and salt and limestone impurities. Lesser amounts of other wastes may also be present.



During the summer of 1977, Diamond Shamrock closed its remaining operations in Painesville. Activities after this point included preliminary site investigations to determine the impact chrome leachate was having on the Grand River. From 1977 through 1982, Diamond Shamrock “capped” one of the waste lakes (the chromate lagoon) with clay and vegetation. This activity, as well as follow-up monitoring, was performed under an Administrative Consent Order between U.S. EPA and Diamond Shamrock.

During March 1984, Ohio EPA completed the first of several Preliminary Assessments for portions of the site. This was the first step in moving the Diamond Shamrock site toward inclusion on the National Priorities List (NPL).

From March 1984 through May 1993, Ohio EPA and U.S. EPA conducted further investigations to support the NPL proposal. In May 1993, Diamond Shamrock was officially proposed for the NPL.

On February 20, 1995, Ohio EPA, under a cooperative agreement with U.S. EPA, began negotiations for a Remedial Investigation/Feasibility Study with 33 Potentially Responsible Parties (PRPs). The PRPs included successors to Diamond Shamrock and current and former owners of former Diamond Shamrock property. These orders were signed by the Painesville PRP Group and others and were journalized by the State of Ohio on September 27, 1995. Following journalization, Ohio EPA formally requested that the site not be finalized on the National Priorities List (Superfund) by U.S. EPA.

For information on the current status of the site, click here.