1.1.1  Incident Category CERCLA incident category: Inactive Production Facility  1.1.2  Site Description 1.1.2.1 Site Location

The Site is located at, and in the area of, 1205 East 7^th Street, Atlantic, Cass County, Iowa. The approximate coordinates of the Site are latitude 41.403718° North and longitude 94.995763° West. The Site is a former dry cleaning facility, which has since been turned into a parking lot for an adjacent commercial building. 

The City of Atlantic has a population of 7,008 (U.S. Census Bureau 2012) and is located in Cass County, Iowa, approximately 45 miles northeast of Council Bluffs and 75 miles west of Des Moines. Land use in the area of the Site is a mixture of commercial and residential. The City of Atlantic Municipal Utility well field is located adjacent to Troublesome Creek. 

1.1.2.2 Description of Threat

Analytical results from samples collected by the Iowa Department of Natural Resources (IDNR) indicate that hazardous substances have been released into the environment at the Site.  Tetrachloroethene (PCE) and its degradation products, including trichloroethene (TCE), are hazardous substances as defined in CERCLA section 101(14), 42 U.S.C. § 9601(14), and as designated in 40 CFR § 302.4.  PCE has been detected in one city municipal well at concentration levels that exceed the EPA’s Maximum Contaminant Levels (MCL) of 5 micrograms per liter (µg/L).  Concentrations of PCE as high as 170 µg/L have been found in one city municipal well.   

1.1.3     Removal Preliminary Assessment/Removal Site Inspection Results Preliminary assessment site activities from August 1982 to February 2, 2012 are taken from written reports.

August 1982 During a water quality survey conducted by IDNR in August of 1982, PCE was detected in municipal well AMU-7 at concentrations as high as 170 µg/L. Subsequent sampling in August 1984 by IDNR showed an increase in PCE concentrations at AMU-7, with levels as high as 260 µg/L.  As a result, AMU-7 was disconnected from the municipal water supply system and has been continuously pumped to provide hydraulic control to the remaining municipal wells. August 1982 to November 1987 Groundwater from AMU-7 was pumped into Buttermilk Creek in an attempt to restrict migration of the PCE to other municipal wells.  In December 1987, the discharge from AMU-7 to Buttermilk Creek was rerouted to the 3^rd street sanitary sewer line for treatment at the city’s public owned treatment works (POTW). August 1987The EPA conducted a soil gas survey to delineate the approximate extent of PCE contamination.  Analytical results suggested the source area was just south of East 7^th Street, about 250 feet east of the former dry cleaner and Iowa Department of Transportation (IDOT) materials testing lab (Table 1).  The report stated that a release of PCE likely occurred at the Site and migrated through surface runoff and groundwater flow to this topographic low.  In addition, the migration from the Site may have followed the storm sewer system along the southern side of East 7^th Street. 1988The EPA assessed the Site using the Hazardous Ranking Score (HRS) model.  Two pathways were scored (groundwater and surface water).  The overall site score was 26.14. In August 1988, IDNR conducted follow-up investigations of PCE contamination to better define the source.  Thirty-four soil gas samples and ten soil samples were collected for analysis.  The sampling focused on the area of the Site and the source area identified during the 1987 EPA investigation.  The investigation confirmed the level of PCE contamination originally detected 250 feet east of the Site.  However, significantly higher PCE levels were detected in soil gas near the Site (greater than 10,000 parts per million (ppm).  Based on these findings, IDNR concluded that the silty, clayey soil beneath the Site is the predominant source of PCE contamination impacting the groundwater.  The soils appear to be contaminated to at least 20 feet below grade (fbg).  IDNR recommended installing groundwater monitoring wells to better define the extent of the PCE contamination near the suspected source. October 2002In October 2002, EPA field activities included 13 soil borings to depths ranging from 23 to 36 fbg, and the installation of three groundwater monitoring wells.  The soil borings were advanced around the previously identified source area.  PCE was identified in soil from two Geoprobe borings and soil from one monitoring well boring.  Groundwater samples were collected from the three monitoring wells.  Analytical results can be found in Table 3.  Monitoring wells locations can be found in document section.   May 2003On May 13, 2003, the EPA collected water samples from Monitoring Wells (MW) MW-1, MW-2 and MW-3 and Atlantic Municipal Utility wells (AMU) AMU 6 & 7.  The monitoring wells were sampled using a standard bailer and passive diffusion bags (PDBs).  Analytical results as high as 4,300 µg/L for PCE was found in MW-2.  Analytical results can be found in Table 3.  July 2003The EPA collected water samples from MW-1, MW-2 and MW-3 and AMU 6 & 7 on July 29, 2003.  Samples were collected using bailers and with PDBs.  Analytical results show PCE concentrations as high as 5,300 µg/L in MW-2 (Table 3).  
 June 2005The EPA and the Environmental Response Team (ERT), with support from the Response Engineering and Analytical Contract (REAC), performed a hydrogeologic investigation of the Site.  The primary purpose of this investigation was to define the nature and extent of groundwater contamination, upgradient of the AMU-7 well, for assessing the applicability of installing a permeable reactive barrier (PRB) for groundwater treatment and protection.  As part of the investigation, six boreholes were installed about 150 feet upgradient of AMU-7. PCE was reported in water samples from all six borings, with the highest concentration of 446 µg/L in the boring farthest east.  Also, the breakdown product TCE was detected in groundwater samples from each boring.  The eastern extent of the plume near the well field was not delineated in this investigation and remains undefined.  Following the investigation, preliminary cost estimates to install a PRB were calculated.  The total costs for this remedial technology were prohibitive to implement under the removal program.

December 2011The EPA collected groundwater samples and performed a HRS evaluation in December 2011.  In addition, groundwater samples were collected from nine active municipal wells and from AMU-7 that is now off line and pumped to the POTW. Analytical results for PCE as high as 2,500 µg/L were found in MW-2 and in AMU-7 PCE results were 87 µg/L (Table 3). The results of the HRS showed a site score of 50 on the groundwater pathway.

February 2012 to July 2012 
OSC Susan Fisher became the OSC of record for the Site on February 3, 2012.

OSC Fisher met with Jon Martens , AMU, and  Keith Wilken, Iowa Department of Natural Resources (IDNR) - Atlantic field office, to discuss the history of the Site on July 11, 2015.

OSC Fisher also met with Rolling Hills Bank & Trust in Atlantic, Iowa on July 11, 2015 to discuss access to the commercial building parking lot to collect future soil and groundwater samples. 
 OSC Fisher talked to property owners to obtain access to their properties to collect groundwater samples in October 2012.  

2.0    Current Activities

2.1    Operations

2.1.1    Narrative –

                              Situation

            2.1.1.1 Current situation

On September 27, 2012, OSC Fisher and the EPA START contractor mobilized to the site.  Proposed sample locations were flagged so the various utility providers could clear the locations.

On October 1, 2012, OSC Susan Fisher, OSC John Frey, Lorenzo Sena (EPA ENSV), and two EPA START contractors mobilized to the site.  The purpose of the site visit was to use the Geoprobe Membrane Interface Probe (MIP) to better delineate the vertical and horizontal extent of contamination at the site.  Fifteen locations were previously flagged in the parking lot where Monitoring Well (MW) 2 is located.  A Geoprobe was used at each location to advance a MIP tool through the subsurface soil to obtain a continuous log of chlorinated volatile organic compounds (VOCs) in soil, and to collect electrical conductivity (EC) results as well (MIP and EC logs found in document section).

On October 3, 2012, MIP logging was completed.  Each MIP log was evaluated and the depth showing the greatest response was notated.  On October 3 and 4, 2012, the Geoprobe was used to collect soil cores at each MIP location.  A soil sample was collected at each MIP location where the greatest response was notated.  Soil samples were collected using discrete interval sampling with the Geoprobe. (Table 2 shows soil sample results, soil sample locations can be found in document section).

Groundwater samples were also collected on October 3 through 5, 2012.  Samples were collected from 12 temporary wells installed with the Geoprobe (Temporary Well Locations map can be found in document section).  Groundwater samples were also collected from three city wells (AMU-6. AMU-10, and AMU-11) and one piezometer belonging to Atlantic Municipal Utilities.  The groundwater samples were collected to further delineate the contamination plume in the vicinity of the municipal water supply wells (Table 3 groundwater sample results).

On January 3, 2013 a meeting was held with Bill Pedicino, EPA Region 7 Hydrogeologist, Ann Jacobs, EPA Region 7 toxicologist, Demetra Salisbury, EPA Counsel for the Site, START Contractor for the project, and OSC Fisher.  The purpose of the meeting was to discuss vapor intrusion sub-slab screening levels and indoor air removal action levels.  Removal action levels can be found in the document section.

2.1.2    Response activities to date

No removal actions have been performed to date.

2.1.3    Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)

                                No PRPs have been identified.
 

AMU              Atlantic Municipal Utilities

ATSDR          Agency for Toxic Substance Disease Registry

CFR               code of federal registration

CERCLA        Comprehensive Environmental Response, Compensation, and Liability Act of 1980

DCE              dichloroethene

EC                 electric conductivity
EPA              Environmental Protection Agency

ERRS            Emergency and Rapid Response Services

ERT               Environmental Response Team

fbgs              feet below grade surface

HRS              Hazard Ranking Score

IDNR             Iowa Department of Natural Resources

IDOT              Iowa Department of Transportation

MCL              Maximum Contaminate Level

MIP               membrane interface probe

MW               monitoring well

OSC              On Scene Coordinator

PCE              Tetrachloroethene

PDB              passive diffusion bags

PID                photoionization detector

POTW            Public Owned Treatment Works

ppm              parts per million

PRB              Permeable Reactive Barrier

PRP              Potential Responsible Party

RAL               removal action level

REAC            Response Engineering and Analytical Contract

SB                 soil boring

START           Superfund Technical Assessment & Response Team

TCE               Trichloroethene

TOC               total organic carbon

µg/L      Micrograms per Liter
µg/kg    microgram per kilogram
µg/m³    microgram per cubic meter
VOCs   volatile organic compounds

PCE (Tetrachloroethylene):           

•       A man-made chemical that is widely used for dry cleaning clothes.

•       It evaporates easily into the air.

•       a colorless liquid with a mild, chloroform-like odor - has a sharp, sweet odor 

TCE (Trichloroethylene):

•       Used to remove grease from fabricated metal parts and in the production of some textiles.

•       PCE degrades to TCE under certain circumstances.

•       A colorless or blue liquid with a chloroform-like odor - has a sharp, sweet odor

For more information about these chemicals go to: http://water.epa.gov/drink/contaminants/basicinformation