Containing harmful contaminants and adjacent to an urban area of Newark and the Passaic River, the site of a former manufactured coal gas plant was in need of remediation.
Over the years, the by-products of the coal gasification process (including coal and tar) had leached into the ground and contaminated both the water and soil. This concerned residents because the area was to be re-developed by the United States Army Corps of Engineers (USACE) as a public green-space for the city of Newark.
Conti was hired to restore the property and performed state of the art remediation techniques to remove Market Street’s contaminants. The team constructed three reinforced steel cofferdams at measurements of approximately 85 feet long, 365 feet long and 200 feet long. When combined with a dewatering system of shallow and more than 100-foot deep wells, piezometers and five tiers of internal bracing, the cofferdams allowed excavation to depths of 60 feet right next to the river. Conti also protected twin active gas mains with 30-inch diameters using 344 cubic yards of jet grout. Once excavated, Conti blended the contaminated soil with clean soil and cement kiln dust and transported it to thermal desorption facilities where it met strict acceptance criteria.
Conti performed 56,810 safe work hours with no lost time accidents and completed the project on schedule. The client re-developed this major riverfront site for the City of Newark and congratulated Conti for a job well done, expressing his satisfaction at having worked with such a professional team.