The Niagara Chemical site occupies 2 acres west of the intersection of Commerce Street and Adams Avenue near downtown Harlingen. Liquid and dry pesticides were formulated at the plant from 1946 to 1962, and pesticide blending and storage continued until 1968.
The plant was shut down and the buildings were razed in 1970, leaving only concrete slab foundations on the site. Three 10,000-gallon underground storage tanks were removed before the TCEQ began remedial investigations.
Superfund Registry and Investigation
On January 16, 1987, the Niagara Chemicals site became one of ten listed on the state Superfund registry. In 1987, the TCEQ entered into an agreed order with potentially responsible parties (PRPs) to conduct the remedial investigation and feasibility study.
During the remedial investigation, soil and groundwater at the site were found to be contaminated with arsenic and organochlorine pesticides at concentrations requiring remedial action.
In 1996, the TCEQ entered into another agreed order with the PRPs to conduct the remedial design and remedial action. The selected remedy consisted of removing and disposing of contaminated soils off-site and monitoring for chemicals of concern in groundwater.
The soil remedial action was completed in 1998. The PRP continued monitoring until groundwater conditions achieved the objectives set forth in the 1996 agreed order. The TCEQ deleted the site from the state Superfund registry in September 2013.
Cleanup is complete. The site needs no additional state Superfund environmental response actions.