Stewarts Laundry, Salina, Kansas

State Coalition for Remediation of Drycleaners Site Profiles

Description
Historical activity that resulted in contamination.

In 1991 & 1992, KDHE conducted a two-phase Expanded Site Inspection(ESI) to evaluate if the Salina PWS site was a possible candidate for the National Priority List. In November 1991, KDHE collected groundwater samples using a hydraulic direct-push probe at the Stewarts Laundry. Field analytical results indicated the presence of PCE at 12.2 ug/L. The conclusion of a RI/FS was that the most likely source of PCE identified resulted from inappropriate storage or disposal of PCE containing waste solvents from the former Stewarts Laundry.

Remediation Status: In groundwater monitoring

Contaminants
Contaminants present and the highest amount detected in both soil and groundwater.

Contaminant	Media	Concentration (ppb)	Nondetect
Tetrachloroethene (PCE)	groundwater
Trichloroethene (TCE)	groundwater

Site Hydrology

Deepest Significant Groundwater Contamination:		62ft bgs
Plume Size:		Plume Length: 1,200ft Plume Width: 300ft Plume Thickness: 30ft
Average Depth to Groundwater:		35ft

Lithology and Subsurface Geology

		Silt Depth: 0-5ft bgs 5ft thick Conductivity: 0.00035ft/day Gradient: 0.001ft/ft
		Clay Depth: 5-12ft bgs 7ft thick
		Sandy silt Depth: 12-25ft bgs 13ft thick
		Clay Depth: 25-32ft bgs 7ft thick
		Med/coarse-grained sand mixed with some gravel Depth: 32-65ft bgs 33ft thick

Pathways and DNAPL Presence

Groundwater

Sediments

Soil

DNAPL Present

Remediation Scenario

Cleanup Goals:

Reduce PCE groundwater contamination to below MCL of 5 mg/L; reduce soil contamination below KDHE RSK level of 180 µg/kg.

Technologies

In Situ Soil Vapor Extraction

Why the technology was selected:
SVE system was chosen for the relatively low cost to address the PCE concentrations in the vadose zone and presence of buildings and utilities.

Date implemented:
June 1, 1998

Final remediation design:
The final design consisted of two SVE wells bored at 8.5 inch diameter. SVE-1 was installed to a depth of 29.68 feet BGS and SVE-2 to a depth of 29.95 feet BGS. Each well consisted of 4 inch ID schedule 40 PVC screen and casing. Each well was completed with 10 feet of 0.020 inch machine slotted screen and the filter pack consisted of 10-20 sand. Subsurface piping consisted of 2 inch ID schedule 40 PVC with flexible tubing connected to the header system within the equipment enclosure. The venting blower was an EG&G Rotron Model DR454R72 blower powered by a 1.5 horespower, 230-260 volt, 3-phase motor with a design capacity of 90 cubic feet per minute at 30 inches of water.

Results to date:
Sampling conducted for three years following the remediation startup indicated significant reduction in groundwater solvent concentrations. PCE concentrations rebounded within the first 2 months, but then significantly decreased. PCE concentrations have slightly fluctuated, but remained consistently lower than the concentrations found up through the first two months of remediation. Measurements recorded within the last year reveal PCE concentrations ranging from 4-17.6 ppm. Most of the recent measurements show PCE concentrations just above the MCL, at 6 ppm. The SVE system removed a total of 101.1 pounds of VOCs after approximately 2.5 years of remediation activities.

Next Steps:
Long-term monitoring since low-level PCE plume is captured by PWS wells. PWS wells are being treated by a municipal-size packed tower air stripper system funded by KDHE and operated by the City of Salina.

Cost to Design and Implement:
16,113

Costs

Cost for Assessment:		12,974
Cost for Operation and Maintenance:		17,174
Total Costs for Cleanup:		46,221

Lessons Learned

Source area was reduced by the SVE system. Multiple PWS wells are contaminated by several gas stations and dry cleaners. The PWS wells pump the water to a dual packed tower air stripper system at the water treatement plant. The $1.2 million system was paid for by the Kansas Dry Cleaning Program and Leaking Underground Storage Tank Program, but operated by the City of Salina.