The order to evacuate an Indiana public-housing complex contaminated with lead came more than three decades after the problem first emerged. Here's a look at key events:
" 1906: What would become the U.S. Smelter and Lead Refinery, or USS Lead, begins operation in East Chicago, Indiana. For 79 years, a copper smelter, lead refinery and secondary lead smelter operated on the site just south of the West Calumet Housing Complex. The U.S. Environmental Protection Agency now says the plant is a likely source of lead contamination throughout neighboring residential areas.
" 1972: The West Calumet Housing Complex is built on the site of the old Anaconda Lead Products facility. Years later, evidence emerges that houses were built on top of toxic demolition debris from the plant.
" 1985: The Indiana Department of Environmental Management samples some residential properties near the USS Lead site and finds elevated lead levels in residential yards. Health officials also find high lead levels in blood screenings on dozens of children in the area.
" 1985: The USS Lead plant closes.
" 1993: The EPA begins cleanup of the USS Lead site. Within a few years, all of the buildings are demolished, with contaminated materials buried in a capped landfill.
" JANUARY 2008: An internal EPA memo notes that the conditions present "an imminent and substantial endangerment to the public health, welfare, and the environment." Later that year, the EPA hauls away more than 1,800 tons of lead-contaminated soil at around a dozen residential properties.
" APRIL 2009: The USS Lead site, the housing complex and hundreds of private homes are added to the EPA's national priorities list of Superfund sites.
" JULY 2012: The EPA proposes a remediation plan that calls for removing up to 2 feet of contaminated soil from properties and replacing it with clean soil. The agency estimates 723 of the 1,271 properties in the area will require cleanup. Mayor Anthony Copeland says a more extensive cleanup is needed, warning the EPA plan would leave East Chicago with a "wasteland."
" JUNE 16, 2016: After receiving detailed soil sampling data, Copeland says in a June 16 letter to the EPA that it's clear soil removals in 2008 and 2011 were "incomplete and ineffective," but he nonetheless presses the EPA to immediately begin the new excavation.
" JULY 2016: The EPA circulates flyers to residents with information on ways of protecting themselves from lead exposure. The mayor sends letters to housing complex residents advising them to relocate temporarily. But two days later, the city housing authority proposes demolishing the complex.
" SEPTEMBER 2016: Federal vouchers to help residents pay rent at new homes go into effect.
This story has been automatically published from the Associated Press wire which uses US spellings