The final phase of the soil cleanup at the Lake Ontario Ordnance Works site off Balmer Road in Porter begins Monday.
The Army Corps of Engineers announced Wednesday that the $600,000 project should be completed in September.
Project manager Brent LaSpada said the 1-acre lot contains TNT and lead left over from an explosives factory that existed on the site more than 75 years ago.
Remediation began last year by stripping away two to three feet of fill above ground level and a foot of topsoil resting on a clay layer. LaSpada said the removed material will be sent to the Modern Disposal landfill in Lewiston.
Jacob A. Zdrojewski, a Corps outreach specialist, said the acre contains no radioactive material. All the nuclear waste from the World War II atomic bomb project and postwar atomic production is now housed in the Niagara Falls Storage Site, which is considered separate from the LOOW site.