LOCKPORT – One block of LaGrange Street may be closed for as long as 18 months as New York State Electric & Gas Corp. performs a state-ordered cleanup of waste that may be more than 160 years old.
The block of LaGrange between Saxton and South Transit streets borders the site of a manufactured gas plant that made gas by baking coal from 1851 to 1927. The site of the plant, about ≥ of an acre, is now covered by a NYSEG electric substation.
The state Department of Environmental Conservation determined that coal tar, as the byproduct from the gas production is known, lies beneath the street.
The tar is about the consistency of motor oil and has been known to seep through the shale and dolomite bedrock in the area to leak into the canal.
The DEC’s 2009 record of decision estimated the cost of the remediation at $11 million.
The street was blocked to traffic Wednesday as the preparation for the work began. NYSEG spokesman Clayton Ellis said the job may last as long as 18 months and that the street will have to be blocked the entire time.
The closing blocks an entrance to a Tim Hortons drive-thru lane at the neighboring Mobil gas station and convenience store. The drive-through remains accessible from the store’s parking lot, however.
“We will certainly do whatever we can to minimize any inconvenience to residents and businesses in the area,” Ellis said.
Some tar-contaminated soils were removed from the convenience store site in 1997, according to a DEC document.
This is the second cleanup of coal tar NYSEG has had to accomplish in Lockport. In 2007-08, NYSEG removed waste at a State Road site, on the opposite side of South Transit Street from the electric substation, after tests showed the tar was leaching through the walls of the Erie Canal.
The canal runs 200 feet west of the substation.
According to a DEC fact sheet issued in November, the cleanup plan requires NYSEG to relocate the control house and 12-kilovolt switch gear at the electric substation before excavation of the coal tar can begin.
The DEC said about 4,000 cubic yards of material will be excavated on the substation property, and 3,200 cubic yards will be removed from beneath LaGrange Street. The waste will be taken away to a thermal destruction facility or a landfill.
Also, 1,200 cubic yards of contaminated sediment will be dug out of the canal after the waterway is drained for next winter.
The asphalt and other clean demolition debris may be used to backfill the trench. Unpaved areas will have at least a foot of fresh soil placed over them.
NYSEG will have to install a wall in the trench down to the bedrock for monitoring purposes and to block any further seepage into the canal.
The bedrock in the affected area lies anywhere from 18 inches to 51 feet below the surface.