Visitors to the George Rogers Clark National Historical Park may soon see more drilling rigs as an effort to detect possible ground water contamination from a coal gasification plant located there decades ago expands.
A southern Indiana gas and electric company installed monitoring wells back in 2014 to periodically check the ground water and soil for possible contamination.
They've found some, according to park superintendent Frank Doughman, but they haven't yet been able to find the edges of the contaminated area.
“These new wells will reach farther to find those edges,” Doughman said. “So they can find how far this problem could have extended.”
These new wells — which will be marked with 10-inch caps upon completion — will be in areas farther away from the memorial itself, places like the French Commons, site of the Spirit of Vincennes Rendezvous each year, and Pearl City.
The coal gasification plant, Central State Gas, first opened in 1876 and sat right where the national park is now. Owned by what is now Vectren Corp., the plant remained in operation into the 1930s.
The memorial was dedicated in 1936.
The plant created coal compressed gas — which was pumped to area houses to power like gas lights and appliances — long before natural gas became so readily available.
“Oddly enough, it's a process very similar to the coal gasification plant in Edwardsport, only that that system is much cleaner,” Doughman said.
Tar coal sludge was a by-product of the process that was stored in underground tanks, both steel and brick.
Many of the brick ones, Doughman said, were left behind.
The first monitoring wells were drilled in the 1990s, Doughman said, to monitor ground pollution. Sixteen additional wells were then added in 2014 and 2015.
And despite the detection of at least some contamination, Doughman said residents' drinking water hasn't been affected.
Tests of the nearby well field from which Vincennes Water Utilities draws residents’ drinking water have also repeatedly come back clean, likely due to the fact that they are very deep.
Still, Vectren wants to continue monitoring the ground water to be sure.
“The concern is that (the contamination) could get into the city's wells,” Doughman said, “but there has been no indication that that is even close to happening.
“This just isn't something people should worry about.”
So for now, Doughman said they are content to continue monitoring. At some point, however, there could be a major cleanup effort.
“There is still question as to a plan for remediation,” Doughman said. “There is possibility they could go in and remove it.
“Or they could stay with long-term monitoring.”
Once the new wells are drilled — just as with the others drilled in 2014 and 2015 — crews with the utility will come periodically to take samples.
This latest round of wells, he said, will be dug beginning in early April. Drilling will likely continue through the end of July.