Drilling work began in March to install more wells for the Central Chemical Superfund site in Hagerstown's North End, according to the Environmental Protection Agency.
The entire cleanup operation at the former pesticide blending site is running behind schedule after a new groundwater contaminant, dioxin, was discovered in 2018, EPA officials said. Construction of a pump and treatment system for contaminated groundwater, previously scheduled for 2018, began this year.
"The reality is dioxin delayed us a couple years. The good news is we're back on track," said Mitch Cron, one of the EPA officials overseeing the cleanup.
Central Chemical Corp. blended agricultural pesticides and fertilizers at the 19-acre site from the 1930s to the 1980s. Raw pesticides manufactured elsewhere were mixed at the site with inert materials to produce commercial-grade products.
Among the contaminants found in the soil, groundwater, surface water and sediment, as well as in the tissue of fish caught downstream from the site, include arsenic, lead, benzene, aldrin, chlordane, DDD, DDE, DDT, dieldrin, and methoxychlor, the EPA has said in the past.
In 1997, the site was placed on a list for the federal Superfund program, designed to address abandoned hazardous materials sites.