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Hazardous Waste Cleanup: Solvay USA Incorporated (Formerly: Rhodia Incorporated) in Morrisville, Pennsylvania

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Cleanup Status

On September 12, 2016, EPA issued the Agency’s Final Decision and Response to Comments to select the Final Remedy for the Solvay USA Inc. facility.   The Final remedy includes the following components:

In addition, the Final Remedy requires, on an annual basis, the then current owner shall submit to EPA a written certification stating whether or not the groundwater and land use restrictions are in place and being complied with.

  •  Soil - The final remedy for the Facility soils consists of:
    • No further action for Areas 1, 2, 9, and Former Manufacturing Area 
    • Remediate Areas 5 and 10 to residential standard by capping these areas 
    • Maintenance and inspections of the existing engineered clay cap over area 6 and the caps over areas 5 and 10 
    • Develop a Post-Remediation Care Plan to verify that the caps remain effective in preventing exposure to soil contaminants beneath the caps.
    • Remediate the Non-Residential Area to non-residential standard by removing the arsenic-impacted soil around sample A6-01 and compliance with and maintenance of land use restrictions to prohibit residential uses of the area.
  • Groundwater -  The Final Remedy for the Facility groundwater consists of:
    • Groundwater at the Facility shall not be used for portable purposes 
    • No new wells shall be installed on Facility property in areas where caps or building foundations acting as caps are required by this Final Remedy.

Cleanup Background

On May 13, 2011, Rhodia, Inc. (Rhodia) submitted a Notice of Intent to Remediate (NIR) to the Pennsylvania Department of Environmental Protection (PADEP) to enter the Facility into PADEP’s Land Recycling Program (Act 2). As part of the NIR submittal, Rhodia indicated the intent to enter the Site into the “One Cleanup Program.” The One Cleanup Program was created through a Memorandum of Agreement (MOA) between EPA Region 3 and PADEP dated April 2004 and is intended to promote collaboration between EPA and the State for the investigation and remediation of contaminated hazardous waste sites.

In January 2012, ARCADIS U.S., Inc (ARCADIS) submitted a Remedial Investigation Work Plan (RIWP). Following EPA and PADEP comments and subsequent responses, the RIWP was approved on February 2, 2012.& The RIWP was implemented between February and May 2012.

In August 2012, ARCADIS submitted a Remedial Investigation Report (RIR) for EPA and PADEP’s review. The data collected during the RI has been used in conjunction with historical data to characterize the potential sources and the nature and extent of constituents of concern (COCs) and to identify and evaluate current and future potential exposure pathways.

In a November 27, 2012 correspondence from PADEP to Rhodia, PADEP provided its approval of the RIR in accordance with the provisions of Act 2, in addition to EPA’s approval of the RIR under the federal Resource Conservation and Recovery Act (RCRA).

In a January 10, 2013 correspondence, EPA provided questions and comments to Rhodia on the information presented in the RIR. EPA and PADEP will be meeting with Rhodia in late January 2013 to discuss EPA’s comments and questions, next steps and remediation of the Site.

Site Investigation Background

In 1979, PADEP required Stauffer to prepare and execute a preliminary investigation of groundwater beneath the Site in response to the closure of onsite landfills.  The preliminary investigation indicated that dissolved arsenic was present in the groundwater at a maximum concentration of 29,400 micrograms per liter (ug/l) detected at a monitoring well near Area 6.  This well consistently contained the highest concentrations of arsenic as it was located near the arsenic sulfide burial site.

Between 1981 and 1994, additional interim investigations of groundwater at the Site were conducted.The results from each of the interim investigations showed that the groundwater beneath the Site was contaminated with aresic.  It was also determined that there are two aquifers present in the region. The shallow water table is encountered from approx. Fourteen to 60 feet below ground surface (bgs).The deep aquifer is present from approx. 130 to 170 bgs. The two aquifers are separated by two distinct clay confining layers.

Shallow groundwater flows toward Biles Creek along the southern edge of the property and to the Delaware River along the eastern edge of the property. Shallow groundwater appears to discharge to Biles Creek and the Delaware River.

In May 1999, ARCADIS G&M initiated remedial investigation activities at the Facility. The investigation was conducted consistent with the PADEP Land Recycling Program (Act 2) to request a release of liability from the PADEP for arsenic that had been historically detected in Facility groundwater.

On August 14, 2001, PADEP approved a non-use aquifer designation for the Facility, as well as for three adjacent properties owned by USX Corporation and WMI Properties; a portion of a property located in Trenton, New Jersey where a sewage plant operated; and the Delaware River.  Groundwater within the described area is not used for drinking or agricultural purposes and the described area does not intersect a radius of ½ mile from a community water supply well or an area designated as a Zone 2 wellhead protection area.

The Act 2 Final Report was approved by PADEP in a letter dated May 22, 2002.

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Site Description

Interactive map of Solvay USA Incorporated (Formerly: Rhodia Incorporated), Morrisville, PA

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The Facility is located in Falls Township, Bucks County, Pennsylvania and occupies approximately 40 acres of a larger 90-acre property.  The 50 acres of the property that is not occupied by the facility are wooded and have not been used for industrial operations or waste management activities.  The Site is bordered to the north by commercial properties, to the south by Biles Creek and vacant property, to the east by the Delaware River, and to the west by wooded areas and Pennsylvania Avenue, and is fenced to restrict access.   

The Facility was operated as an inorganic chemical production facility from 1948 until December 2001 and has had several different owners/operators, beginning with Victor Chemical in 1948.  Stauffer Chemical bought the property in the mid-1960s and subsequently sold it to Rhône-Poulenc Basic Chemicals (Rhône-Poulenc) in 1987.  In 1997, Rhône-Poulenc transferred its chemical assets, including the Morrisville Facility, to Rhodia, Inc. (Rhodia) and spun Rhodia off as a separate company in 1998. Operations were discontinued at the Facility in late 2001 and, in early 2002, Rhodia began to demolish buildings down to concrete slabs.

The Facility remained dormant from late 2002 through 2008. In 2008, demolition was re-initiated and the remaining buildings were razed.  The only building currently remaining onsite is the former office building.   

The primary chemical produced at the Facility was phosphoric acid. The main raw material for the production of phosphoric acid is phosphorus, which contains trace amounts of arsenic. Certain wastes from the production process were treated and disposed in onsite acid-waste ponds and landfills from 1948 through 1979.  There are 10 defined waste disposal areas, primarily in the southern portion of the site.  The wastes disposed in these areas include phosphorus pentasulfide (P2S5), sodium phosphates, and arsenic sulfide. Other wastes were stored in 55-gallon drums and shipped off-site for disposal.

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Contaminants at this Facility

Arsenic is the primary constituent of concern at this facility. The groundwater contains arsenic above the Safe Drinking Water Act Maximum Concentration Limit (MCL) of 50 ug/l, which is a health-based standard for drinking water. The groundwater flows toward Biles Creek and the Delaware River. At the property boundary near the Delaware River, analysis shows arsenic concentrations up to 537 ug/l. At the boundary near Biles Creek, the arsenic levels are below the MCL.

Although additional surface and subsurface soils sampling must be completed, information collected to date indicates the subsurface soils are contaminated with arsenic. The wastes reportedly placed in these landfills had hazardous levels of arsenic, and the groundwater samples taken directly beneath one of the landfills showed arsenic levels at 12,000 ug/l.

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Institutional and Engineering Controls at this Facility

To ensure that groundwater at the Site is not used as a source of drinking water and that the property is not used for residential purposes in the future, EPA will be working with PADEP and Rhodia to implement institutional controls and place land and resource use restrictions on the property in the form of an Environmental Covenant.

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Land Reuse Information at this Facility

The Site is currently vacant except for the former office building. The future anticipated use for the site is industrial and/or commercial use. The site is not anticipated to be used for residential purposes.

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Site Responsibility at this Facility

RCRA Corrective Action activities at this facility have been conducted under the direction of EPA Region 3 with assistance from PADEP.

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