CHELSEA — A developer is digging up and replacing thousands of pounds of contaminated soil at a parking lot near the High Line, to clear the way for future development.
The entire block between West 17th and 18th streets from 10th to 11th avenues was home to a 19th century gas processing plant, which left the underlying soil contaminated by industrial byproducts including coal tar.
HLP Properties, a division of Edison Properties, began extensive work last week to dig up the dirty soil and replace or stabilize it in sections that are as much as 7 feet deep.
"We're remediating the site, cleaning it up...to prepare it for future development," HLP executive Anthony Borelli said.
The company hopes to eventually build a mixed-use structure with ground-floor commercial space and residential units on the upper floors, Borelli said. The height of the building has not yet been determined, Borelli said.
Borelli declined to give the cost of the remediation project.
In the 1800s, the West Chelsea block housed 18th Street Gas Works, which made heating and cooking gas from lumps of coal, leaving the waste products behind, HLP said.
The eastern part of the site, which is closest to the High Line, contains less contaminated soil, which means HLP will only have to remove about 3 feet of soil. But further west, the company will have to dig deeper and either take away the coal tar, mix it with cement to stabilize it or install an underground barrier wall to contain the coal tar plus contaminated groundwater.
Borelli said the work will be continually monitored to make sure nearby air, water and soil are not contaminated, and that a website will contain detailed updates.
"We set our measures to be very conservative, so at the first indication of something unusual, it will trigger an electronic signal or one of our staff people will become aware of it and we'll immediately address the concern," he said.
The project will take about a year, with the first phase, including work under the High Line, set to be complete by the end of the year.
After the work is done, it will likely be another few years before anything is built, the company said. In the meantime, the block will continue to be used as a parking lot.
