Soil Vapor Extraction (SVE) and Monitored Natural Attenuation (MNA) at Three Drycleaner Sites, Various Locations

Site Name:

Multiple (3) Drycleaner Sites - SVE/MNA

Location:

- Aiea Laundry, Naval Station Pearl Harbor, HI
- Dry Clean Inn, Lauderhill, FL
- Former Dollar Cleaners, Lake Worth, FL

Period of
Operation:

- Aiea Laundry, 1996 - 1998
- Dry Clean Inn, June, 2000 - June, 2001
- Former Dollar Cleaners, December, 2001 - April, 2002

Cleanup
Type:

Full scale

Technology:
SVE and MNA
- SVE systems varied by site. One site (Dry Clean Inn) used 2 horizontal extraction wells installed beneath the service doors of the facility and the floor slab near the drycleaning machines. A second site (Former Dollar Cleaners) used 6 wells beneath the floor slab of the facility and an adjacent bay in the strip shopping center. The wells applied a vacuum of 14.5 to 64 inches of water and drew 70 to 98.5 scfm soil vapor at depths from 3 to 4 ft bgs.
- At one site, pump and treat of contaminated groundwater was also conducted. The system was designed to recover diesel fuel and prevent further migration of floating product on the groundwater surface. The system continued operation for an unspecified period of time after the SVE system was shut down.
- Natural attenuation was selected for the groundwater remedy for all three sites due to the low contaminant concentrations present in groundwater and the evidence of active reductive dechlorination (PCE degradation products present).

Cleanup Authority:
State

Contacts:
Varied by site

Contaminants:
Chlorinated Solvents
- Soil contamination consisted of PCE, TCE, cis-1,2-DCE, and vinyl chloride.
Concentrations varied between the sites, ranging from 190 µg/kg to 3,200 µg/kg of PCE
- Groundwater contamination consisted of PCE, TCE, cis-1,2-DCE, trans-1,2-DCE, and vinyl chloride. Concentrations varied between the sites, ranging from 19.9 to 546 µg/L for PCE, 27.4 to 61.9 µg/L for TCE, 63.7 to 127 µg/L for cis-1,2- DCE, 2.6 to 3.81 µg/L for trans-1,2-DCE, and 3.9 µg/L for vinyl chloride.

Waste Source:
Waste and wastewater from drycleaning operations

Type/Quantity of Media Treated:
Soil and Groundwater
Groundwater plume areas ranged from 3,200 ft2 to 8,400 ft2

Purpose/Significance of Application:
Use of SVE and MNA for remediation of chlorinated solvents in soil and groundwater at drycleaner facilities

Regulatory Requirements/Cleanup Goals:
Soil
- For two sites, cleanup goals were based on state regulatory standards which included 0.03 mg/kg leachable PCE. For the third site, the cleanup goal for soil was the U.S. EPA target risk range (actual values not specified).

Groundwater
- Cleanup goals were based on drinking water MCLs, which was specified for 2 sites as 3.0 µg/L for PCE and TCE, 70 µg/L for cis-1,2-DCE, 100 µg/L for trans-1,2-DCE, and 1.0 µg/L for vinyl chloride.

Results:
- All the sites reported that SVE reduced PCE in soils to below cleanup levels.
- Two sites (Dry Clean Inn and Former Dollar Cleaners) reported that contaminant concentrations in groundwater were below cleanup target levels in the last two monitoring events. Both sites received Site Rehabilitation Completion Orders. No information was provided on the results of MNA at the third site.

Cost Factors:
Design and implementation costs for SVE systems ranged from $109,000 to $135,000, and annual O&M costs for SVE systems ranged from $28,000 to $30,000.

Description:
SVE and MNA was conducted at three drycleaner sites contaminated with chlorinated solvents from leaks, spills, or dumping of drycleaning solvents or wastewaters. All three sites reported that SVE reduced PCE concentrations in soil to below cleanup levels. Two sites reported that contaminant concentrations in groundwater had been reduced by MNA to below cleanup levels in the last two monitoring events. Both sites received Site Rehabilitation Completion Orders. Information on groundwater contaminant concentrations for the third site was not provided. Reported design and maintenance costs for SVE ranged from $109,00 to $135,000. Reported O&M costs for SVE systems ranged from $28,000 to $30,000.