General Information

Site Name and Location:		Former Cool City Cleaners Two Rivers, Wisconsin, United States
Description: Historical activity that resulted in contamination.		Cool City Cleaners operated from 1939 to 1982 and is located on a small, steeply sloped property of approximately ½ acre in small town urban setting. Stoddard solvent was used the entire time the dry cleaner operated. In the mid 1950s, PCE solvent was added as another cleaning option until the facility closed in 1982. Both solvents were stored in ASTs or drums. When the dry cleaner closed, the building was renovated for commercial and residential use. The lower level facing the water is a residence and the upper level, facing a busy commercial corridor, is a real estate office. The site is located at the tip of small peninsula at the confluence of two rivers.

Contaminants:

Contaminants: Contaminants present and the highest amount detected in both soil and groundwater (please avoid giving ranges).		Contaminant Conc in GW Conc. in Soil 1,2,4-trimethylbenzene 0.460 mg/L 580 ppm 1,3,5-trimethylbenzene 0.181 mg/L 150 ppm Benzene 0.160 mg/L cis-1,2-Dichloroethene 8.950 mg/L naphthalene 0.133 mg/L Tetrachloroethene (PCE) 0.230 mg/L 8 ppm Trichloroethene (TCE) 0.434 mg/L Vinyl Chloride 0.384 mg/L
Other Contaminants Present: Indicates what other contaminants were found on-site		MTBE (off-site) chloromethane
Deepest Significant Groundwater Contamination:		7-20 feet
Plume Size:		~1/4 acre

Site Hydrology:

Depth to Groundwater:		7 - 14 feet (site on slope)
Lithology and Subsurface Geology:		Soil at the site consists of layers of clay, sand, and silt overlaying a thick clay layer. The shallow water bearing layer is a five-foot sand layer with varying grain sizes and silt content. The site sits on a slope and therefore the depth to the water table ranges from 7 to 14 feet. Groundwater discharges directly to the river at the southern and western boundary of the site. Hydraulic conductivity in the sand layer is approximately 6x10-4 cm/sec. The average linear velocity is about 30 feet/yr.
Conductivity:		6 x 10-4 ft/day
Gradient:

Pathways and DNAPL Presence:

Pathways:		Groundwater Soil
DNAPL Presence:		No

Vapor Intrusion Pathway:

Has the potential for vapor intrusion (VI) been evaluated?		Yes
If the site has been evaluated, how was it evaluated?		Soil vapor and/or Sub-slab vapor sampling Indoor air sampling Compared sample concentration to screening criteria
Results of VI Evaluation:		A completed VI pathway has been indentified
Has a vapor mitigation system been installed?		Yes
Type of Vapor Mitigation System(s):		Sub-slab Depressurization
Additional VI Information:		The vapor intrusion risk to the residence was evaluated via 24-hour time integrated air sampling with SUMMA canisters. Although indoor air levels did not exceed US EPA air screening values, there were elevated solvents detected in sub-slab vapor samples. Therefore a sub slab depressurization system (radon type mitigation system) was installed in the building. Several years of indoor air monitoring after the system was installed showed a steady decrease in indoor air solvent concentrations.

Remediation Scenario:

Cleanup Goals:		To protect human health and the environment while allow succesful reuse of the building. To achieve closure and compliance with Wisconsin Administrative Code Ssandards. The site was first reported to the Wisconsin Department of Natural Resources in 1999 when trimethylbenzenes (TMB) and other volatile organic compounds (VOC) were noted in soil at depths of 8 to 10 feet. Site investigation activities were performed between December 2001 and September 2003 and found varying degrees of PCE and its breakdown products, Stoddard solvent, and other contamination in shallow groundwater. No free phase product was encountered. Petroleum contamination was discovered upgradient and downgradient of the dry cleaner during site investigation activities. MTBE and BTEX contaminants in groundwater at the site were attributed to an off-site source and have co-mingled with the dry cleaning solvents.
Remedy Level:		Full Scale Remedy

Technologies:

Technologies Used:		In Situ: Bioremediation Monitored Natural Attenuation Cap
Other technologies used:		Edible Oil Substate injection
Why the technology was selected:		to enhance reductive chlorination at source area
Date implemented:		September 2007
Final remediation design:		Monitoring for natural attenuation was conducted at the site quarterly and semi-annually for 3 years when a steady increase of 1,2 DCE and TCE was noted in a downgradient well adjacent to the building. The remedial action plan was amended and a carbon enhanced remedy was added. In August 2007, 220 gallons of 60% solution of emulsified edible oil (EOS) substrate were injected into 12 injection wells located within the building and outside of the building spaced about 10 feet apart.

Results and Next Steps:

Results to date:		Subsequent to the injection, five more quarters of groundwater monitoring and gas monitoring were conducted until September 2008. Prior to the injection, TOC concentrations were less that 20 mg/L, ORP readings were generally less than -40 mV, and DO was less than 1 mg/L. It was assumed that reduced conditions were already present due to the off-site PVOC plume passing through the site. At the most impacted monitoring well PCE, TCE, and cis 1,2 DCE dropped significantly after the carbon injection. As expected, ethene and VC increased. The EOS injection increased the TOC to over 100 mg/L but within 1 year, levels dropped back to 20 mg/L. PCE, TCE and cis 1,2 DCE levels also returned to their pre injection levels within one year indicating that all of the EOS had likely been consumed. Monitoring wells nearest the river exhibited low to very low levels of contaminants indicating reductive chlorination was occurring and continues to occur within the site prior to the groundwater discharging into the surface water.
Next Steps:		Pre- and Post- Results of the most impacted monitoring well (MW-2) Contaminant Pre injection (ug/L) Post injection (one year later) ug/L PCE 93.3 38.7 TCE 4,639 434 12 cis DCE 8,900 2,950 12 trans DCE 298 82.4 VC 68 384 Closure was requested for the site in November 2009 and it was granted closure under NR 726 Wisconsin Administrative Code in April 2010. The site is listed in Wisconsins Registry of Closed Remeidiation Sites with residual soil and groundwater contamination. Cap maintenance and continued vapor mitigation system operation and maintenance are part of the permitted closure of the site.

Costs:

Cost for Assessment:		$60,150
Cost to Design and Implement:		EOS injection: $63,421
Cost for Operation and Maintenance:		GW & vapor monitoring, project management, Closure documentation: $49,610
Total Costs for Cleanup:		$173,188

Lessons Learned:

Lessons Learned:

MNA monitoring should be conducted for at least three years to see if conditions change. Health Dept would likely recommend a subslab depressurization system if subslab is impacted but indoor air is not.

Contacts:

Principal Point of Contact:

Annette Weissbach WDNR-Remediation & Redevelopment Program 2984 Shawano Avenue, Green Bay WI 54313-6727 phone: (920) 662-5165 annette.weissbach@wisconsin.gov

Site Specific References:

Site Specific References:

http://dnrmaps.wisconsin.gov/efiles/Ner/Manitowoc/02%20ERP/0236228354/0236228354.pdf

Images:

Images of Site: