Carousel Cleaners, Oregon City, Oregon

State Coalition for Remediation of Drycleaners Site Profiles

Description
Historical activity that resulted in contamination.

Carousel Cleaners is an active retail dry cleaner located in Oregon City, Clackamas County, Oregon (NW ¼, Section 38, Township 2S, Range 2E). The site topography and surface gradient are relatively flat. Several residences and commercial businesses are located within the immediate vicinity of the site. The site is bounded by an apartment complex to the east, a vacant lot to the north, and a small business park to the south. In July 1999, soil and groundwater samples were collected at the site as part of a preliminary site investigation. PCE was detected in soil boring samples from 35 to 1,010,000 micrograms per kilogram (ug/kg). The location with 1,010,000 ug/kg of PCE is adjacent to the back door to the dry cleaning facility. PCE was also detected, at 0.7 ug/L, in a groundwater sample collected from the facility industrial supply well completed in the deep basalt aquifer. The supply well is on the south side of the property approximately 100 feet downgradient of the primary source area.

Remediation Status: In active remediation

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

Contaminant	Media	Concentration (ppb)	Nondetect
Tetrachloroethene (PCE)	groundwater	25,700 ppb
Tetrachloroethene (PCE)	soil	7,000,000 ppb

Site Hydrology

Deepest Significant Groundwater Contamination:		150ft bgs
Plume Size:		Plume Length: 100ft Plume Width: 50ft
Average Depth to Groundwater:		15ft

Lithology and Subsurface Geology

		silt Depth: 0-30ft bgs 30ft thick Gradient: 0.002ft/ft
		fractured basalt Depth: 30ft bgs

Pathways and DNAPL Presence

Groundwater

Sediments

Soil

DNAPL Present

Remediation Scenario

Cleanup Goals:

Final cleanup goals yet to be established. Likely cleanup goals for groundwater and soil will be based on vapor intrusion modeling, and protection of deep aquifer at the MCL of 5ppb for PCE.

Technologies

In Situ Bioremediation

Why the technology was selected:
Vendor funding of field scale demonstration project for the biological amendment products (BioRem H10). SVE was subequently identified as an IRAM for soil based on pilot testing where significant contaminant reduction was observed.

Date implemented:
Pilot Study initiated in spring 2001, and terminated in winter 2003 after 2 years of testing.

Final remediation design:
Biorem Pilot Study: For the vadose zone treatment, trenches were cut along the perimeter, and in the center, of the 15 by 15-foot area to be treated located next to back door. The trenches were spaced so that no more than a 5-foot gap exists between any two trenches. The trenches were cut to a depth of 5-feet BGS, approximately 1-foot above the zone of greatest contamination. For the saturated zone, one new injection well and one existing monitoring well used for injection of biological amendments into the aquifer.

Results to date:
BioRem H-10 has been demonstrated to degrade PCE without generation and accumulation of more toxic daughter products, namely TCE and vinyl chloride.

Cost to Design and Implement:
$60,000 for all technologies

In Situ Soil Vapor Extraction

Date implemented:
SVE system completed in August 2005.

Final remediation design:
SVE System: four 20-foot long, 2" horizontal wells (4.5 feet deep); four vertical wells to 30 feet, screened 5-30 feet. Water table (seasonal) at 15 -20 feet bsl.

Next Steps:
SVE performance report will be evaluated to assess system effectiveness. Initial performance report due April 2006.

Cost to Design and Implement:
$60,000 for all technologies

Costs

Cost for Assessment:		$101,000
Cost for Operation and Maintenance:		$55,000
Total Costs for Cleanup:

Lessons Learned

1. Site investigations need to be more comprehensive. Significant source material in vadose zone should have been addressed initially through alternative means than biological amendment flushing (e.g. SVE or removal)

Contacts

MArk Pugh, Project Manager
DEQ Northwest Region
2020 SW 4th Avenue, Suite 400
Portland, OR 97201
E-mail: Pugh.Mark@deq.state.or.us
Phone: (503)229-6662
Fax: (503)229-6945

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U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

State Coalition for Remediation of Drycleaners Site Profiles