Operable Unit 2 (facility and groundwater)
October 2024
EPA is overseeing the environmental investigation at Operable Unit 2 conducted by the parties potentially responsible for the contamination. Operable Unit 2 (OU2) is the name for the former USS Lead facility and the groundwater beneath the USS Lead site and the residential neighborhood. Read more about the agreement or Administrative Order on Consent. (pdf) (2.61 MB)
Contractors working on behalf of the potentially responsible parties installed groundwater monitoring wells in the residential neighborhood in late 2018. These wells and the wells at the former facility were sampled every three months from shortly after. In 2019, soil samples were taken from the non-excavated wetlands on the southern half of facility. Tissue samples from plants and invertebrate animals were collected as part of an ecological assessment in 2019.
Data from 2018 and 2019 sampling efforts were presented to EPA in a draft Remedial Investigation Report in January 2020. The report showed a need for additional soil and groundwater sampling conducted in March and June 2021. October 2024, EPA determined that additional sampling is needed and is reviewing sampling plans.
EPA collected dust and sump water samples in a subset of homes in Zone 3 in response to concerns about groundwater seepage into basements. EPA is not aware of any on-site residences where a site-related risk of exposure to contamination from groundwater seepage exists in the basement.
Groundwater use and basement evaluations determined that groundwater is not used for drinking purposes. All residents are connected to East Chicago municipal water, which uses Lake Michigan as its water source. EPA is not aware of any household use of groundwater in the neighborhood.
EPA decided to first address areas of the site that present the most risk to the public, making the contamination in the residential areas in Operable Unit 1 (OU1) the priority before initiating an investigation at Operable Unit 2. Access to the land area of OU2 is restricted. Risk to the public from OU2 contamination is much lower than OU1.