News of Riverton, Lander and Fremont County, Wyoming, from the Ranger's award winning journalists.
More monitor wells drilled to check contamination from city-owned lot
Feb 18, 2014 - By Alejandra Silva, Staff Writer
Traffic through the 300 block of East Main Street in Riverton was restricted Tuesday as groundwater contamination testing continued as part of the Storage Tank Program Riverton 2 Remediation.
The project being conducted by the Wyoming Department of Environmental Quality is tied to the field work and sampling that began in December related to the vacant lot on 422 E. Main St. that is now owned by the city.
Bright orange cones blocked off the south side of Main Street between Broadway Avenue and East Fifth Street to allow URS Corporation of Salt Lake City to drill and install three soil gas monitoring wells.
The wells will help determine whether groundwater possibly contaminated with chlorinated solvents evaporated to the soil above 422 E. Main St. and created vapor intrusion problems at the properties south of the vacant lot. A permit issued by the city to URS stated that two wells are to be installed on the south side of Main Street in the parking area, next to the curb and another on the west side of the 5th Street East, next to the curb.
Permit technician with the city, Kristi Petersen said Inberg Miller Engineers are performing the well drilling and work could continue into Wednesday.
The job was complicated Tuesday when drillers broke a water line supplying the building at 417 E. Main St. The water line's location had not been marked properly before drilling.
Repairing the break will require removal of thick, hard concrete installed during the 2004 Main Street rebuild. The fix could take a couple of days.
Petersen added that water use precautions for property owners on Main Street were not requested from URS, therefore no notice was passed on of Tuesday's work. But the broken line could require a temporary shutoff when the repaired line is tied into the main.
In groundwater sampling done in the past, DEQ reports said chlorinated solvents were found in groundwater samples taken from the former dry cleaning operation that was on that vacant lot, which also was the location of a gasoline station in the past. DEQ said additional testing would confirm those findings.
The city took ownership of the lot and paid more than $81,000 last year to demolish the former Daisy Cleaners building and perform asbestos removal. The DEQ's Storage Tank Program also helped with petroleum contamination.