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 1987

The 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.

1988

The 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 2002

In 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 2003

On 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 2003

The 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 2005

The 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 2011

The 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.  

September – October 2012

On October 1, 2012 , the Geoprobe Membrane Interface Probe (MIP) was used to better delineate the vertical and horizontal extent of contamination at the Site.  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 can be found in the document section.)

February 2013

On February 6, 2013, the EPA met with Rolling Hills Bank & Trust.  The meeting was held to discuss vapor intrusion sampling at the bank and commercial building, and collection of additions soil and groundwater samples at the commercial building property.  Rolling Hills Bank & Trust gave access to collect vapor intrusion samples.  Access to collect vapor intrusion samples was also given by 10 other properties in Atlantic in the vicinity of the commercial building parking lot.

On February 12, 2013, the EPA collected 7 indoor air samples and 9 subslab samples. 

March 11 to 13, 2013

On March 11, 2013, the EPA collected soil samples around the commercial building and in the parking lot, and one indoor air sample.  The purpose of collecting soil samples is to further define the horizontal extent of contamination in the soil in the source area.

May 20 to 23, 2013

The EPA installed two deep soil borings in the parking lot of the commercial building to further define the extent of PCE contamination and to log the characteristics of the Dakota Sandstone at the source area.  
 

June 4 - 5, 2013

On June 5, 2013, three additional Geoprobe borings were advanced north of the source area to determine if contaminated soil has extended under the road.  PCE was reported at 61 µg/kg in soil boring (SB) SB-3 at a depth of 23-24 fbgs.  Table 2 shows soil sample results. 

September 2014

 On September 4, 2014, the EPA held a Regional Decision Team (RDT) meeting to discuss a proposed removal action using in situ thermal technology (ISTT) at the Site.  

Five observation wells were scheduled for installation the week of September 15, 2014.  However, drilling activities took longer than anticipated and only three wells were installed the week of September 15, 2014.  The remaining two wells will be installed the week of October 6, 2014.

During the week of September 15 and 22, 2014, OSC Fisher held various meetings with AMU, IDNR, Atlantic City Council and Rolling Hills Bank & Trust to discuss the history of the Site and possible future removal and remedial actions.

October 2014

On October 1, 2014, OSC Fisher and Dave Hoefer, Branch Chief, EPA Regional Counsel, attended the Atlantic City Council meeting at 5:30.  OSC Fisher presented the history of the Site and possible future removal and remedial actions.  OSC Fisher also explained the need for the city to support the listing of the Site on the National Priorities List.  Dave Hoefer explained how the process works and addressed concerns by council members.  The city council voted to support the listing of the Site on the NPL.  The city council requested the Site be named PCE Former Dry Cleaners.

OSC Fisher met with Iowa Department of Transportation (IDOT) to discuss their plans for work on the highway adjacent to the parking lot and the commercial building where the source area is.  IDOT gave the EPA access to collect soil samples underneath the Highway adjacent to the Site.

December 8, 2014

Soil samples were collected from beneath Highway 6 and at the Site.  A map showing sampling locations can be found in the document section.   

2.0    Current Activities

2.1    Operations

2.1.1    Narrative –

                                Situation

            2.1.1.1 Current situation
            

March  - May 2015

March 30, 2015

On March 30, 2015, the EPA and START mobilized to the Site to collect vapor intrusion indoor air and subslab soil gas samples at 10 locations.  Table 4 shows the locations and analytical results.

The highest analytical results were found at 315 Chestnut street. PCE contamination was found as high as 2,300,000 µg/m³ in the sub slab and 550 µg/m³  in the indoor air.  Because 315 Chestnut does not appear to be in the area of the PCE Former Dry Cleaner plume, a new Superfund Site was developed called PCE Chestnut.

March 31, 2015

On March 31, 2015, OSC Fisher met with IDOT regarding the Highway 6 work scheduled for June or July 2015.  The EPA will be removing approximately 5 feet of soil from beneath Highway 6 adjacent to the Site after the top of the highway has been removed.  Plans for the highway work were discussed at the meeting.

April 1 to 14, 2015     No on-site activity.

April 15, 2015

A preconstruction meeting was held at IDOT for the Highway 6 work.  Road construction is scheduled to begin on June 8, 2015.  Bluffs Paving is the contractor doing the work for IDOT, and HDR will be doing the oversight of the construction work for IDOT.  The EPA will excavate and backfill the excavation area.  It is possible to use the soil that is being removed from under the highway in other areas of the construction.  The EPA will make plans to collect verification samples of the soil to confirm it is acceptable to use as backfill.  IDOT does not require compaction rates during backfill activities; soil must be rollered in.  The EPA will be allowed to use an area behind the AMU electric station to stockpile excavated soil before hauling it to the landfill. (The stockpile area will be sampled before use and after use.)  The sewer line that runs north–south under the highway in the PCE-contaminated area will be excavated and replaced.  The sewer is approximately 11 fbg.  The EPA will provide oversight of the investigation and truck the excavated soil off site.

April 16 to May 5, 2015     No on-site activity.
 

May 6, 2015

A second preconstruction meeting was held at IDOT for the Highway 6 work.  OSC Fisher mobilized to the Site for the meeting.  This meeting was to fine tune details of the construction.  The start date will be May 26, 2015.  The first task will be milling the highway.  After the milling work is complete, the east end of the highway will be removed first so EPA excavation activities can begin.  The EPA will need to be on site to begin excavation the first or second week of June. Bluffs Construction will give a more accurate date as we get closer to construction time.  The EPA will have ten days to excavate and backfill their area after excavation begins.

May 7 to 10, 2015     No on-site activity.

May 11, 2015

On May 11, 2015, OSC Fisher and START mobilized to the Site to collect soil samples from beneath Highway 6 west of the area of the highway where the EPA will be excavating.  The purpose of the sampling was to verify the soil for backfill use.  Soil was analyzed for volatile organic compounds (VOCs).  Analytical results showed no detection for VOCs.  A copy of the analytical results can be found in the document section. 

May 12 to 14, 2015     No on-site activity

May 15, 2015

PCE Former Dry Cleaner Action Memorandum was signed on May 15, 2015.

2.1.2    Response activities to date

An Action Memorandum was signed May 15, 2015.

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 (Tetrachloroethene):           

•       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 (Trichloroethene):

•       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