Norge's Cleaners, Hays, Kansas

State Coalition for Remediation of Drycleaners Site Profiles

Description
Historical activity that resulted in contamination.

The Former Norge’s Cleaners was identified as the source of a perchloroethylene (PCE) release that impacted PWS wells in 1984. The facility is located in a commercial district and the contaminant plume extends beneath residential and commercial areas. Kansas Dept. of Health and Environment (KDHE) also identified contamination resulting from two downgradient drycleaners: Former Royal T Drycleaner and Former Suburban Cleaners. KDHE treated the three areas as one site, because the PCE contaminant plumes commingled. KDHE conducted site investigations in 1994-1997 and began SVE remediation in 1997 and Dual Phase Extraction in 1999. A downgradient municipal packed tower air stripper system was also installed in 1999.

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

Contaminant	Media	Concentration (ppb)
Tetrachloroethene (PCE)	groundwater	3,500,000 ppb
Tetrachloroethene (PCE)	soil	24,000 ppb
Trichloroethene (TCE)	groundwater	15,000 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:		50ft bgs
Plume Size:		Plume Length: 7,920ft Plume Width: 1,500ft
Average Depth to Groundwater:		48ft

Lithology and Subsurface Geology

		Silts and clays, with interbedded sand layers, 6 inches to 3 ft in thickness Depth: 0-35ft bgs 35ft thick Conductivity: 1.2ft/day Gradient: 0.052ft/ft
		Poorly sorted sand layer with fine to coarse gravel and caliche Depth: 35-40ft bgs 5ft thick
		silty clay Depth: 40-57ft bgs 17ft thick
		bedrock Depth: 57ft bgs

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:
Initial SVE system was chosen for the relatively low cost to address the high PCE concentrations in the vadose zone and presence of buildings and utilities. A dual phase extraction system was installed to enhance the SVE system by lowering the water table to pull out additional vapors via SVE. The Kansas Drycleaning Program was also able to purchase some used equipment from the Kansas LUST Program for a very reasonable cost.

Date implemented:
SVE - 1997 Dual Phase Extraction - 1999

Final remediation design:
SVE - four SVE wells. Dual phase extraction system - 4 groundwater extraction/SVE wells in conjunction with two of the four existing SVE wells. Each extraction well was designed to remove five gallons per minute (gpm) for treatment by a shallow tray air-stripper system. The tray stripper was designed to reduce 3,000 µg/L influent concentrations to less than 3 µg/L effluent concentration. Groundwater is treated and discharged to a sanitary sewer. Sequestering agent is used to prevent fouling. In March 2001 a groundwater extraction well (PWS-20WTA) was installed. A packed tower air stripper paid for by the DFRTF and the UST trust fund treats the water before entering the plant.

Results to date:
Source area: 95% reduction of PCE in groundwater monitoring wells downgradient of the remediation system. SVE removal - 2,000+ lbs of VOCs. The shallow tray air stripper has reduced 3,300 µg/L influent concentrations to less than 3 µg/L. Over 36 lbs of VOCs has been removed from the groundwater run through the tray stripper.

Next Steps:
Some cross-gradient wells remain contaminated at original levels indicating some source area remains contaminated.

Cost to Design and Implement:
SVE - $28,550Dual Phase - $69,835

Ex Situ Air Stripping

Date implemented:
SVE - 1997 Dual Phase Extraction - 1999

Next Steps:
Some cross-gradient wells remain contaminated at original levels indicating some source area remains contaminated.

Cost to Design and Implement:
SVE - $28,550Dual Phase - $69,835

Ex Situ Pump and Treat

Date implemented:
Dual Phase Extraction - 1999 Groundwater Extraction Well - March 2001

Next Steps:
Some cross-gradient wells remain contaminated at original levels indicating some source area remains contaminated.

Cost to Design and Implement:
SVE - $28,550Dual Phase - $69,835

Costs

Cost for Assessment:		$52,035
Cost for Operation and Maintenance:		SVE only - $9,573 / 7 months; Dual Phase - $73,232 / 72 months
Total Costs for Cleanup:

Lessons Learned

1. Lowering of the water table allowed a much larger zone for SVE to remove soil gas vapors and greatly enhanced the SVE effectiveness.
2. Source area removal under buildings was extremely difficult to reach with SVE in silt/clays.
3. Jet pumps were used in extraction wells due to anticipated fines in the formation. Piping runs of 50-200 ft and did not work well with the jet pumps. The pumps tended to lose their prime, and as a result, lost pumping ability.
4. Improper contruction caused problems on certain well heads. Better oversight and installation could have prevented additional unneeded maintenance.
5. Sensaphone SCADA 3000 (a Supervisory Control and Data Acquisition system) was used at this site. This was one of the first SCADA 3000 units used in the field, and caused problems due to being located too close to the electrical panel. Electromagnetic fields generated from motor starters caused electrical disturbance which deleted SCADA programming.
6. Sequestering agent pump was not tied into the SCADA shut-down sequence. As a result, sequestering agent continued to pump following shut-down and plugged the piping and tray stripper.
7. Dual phase extraction system was very successful in the area influenced by the extraction wells. Additional wells are needed to capture additional source area.