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New Hampshire Department of Environmental Services

Site Summaries

Chlor-Alkali Facility (Former)
Contact: Drew Hoffman (603) 271-6778

The former Chlor-Alkali facility was historically located on a parcel approximately 4.6 acres in size on the east bank of the Androscoggin River just downstream of the Sawmill Dam in Berlin, New Hampshire.

From 1898 to the 1960s, chlorine, caustic soda and hydrogen were produced using electrolytic cells in “cell houses” on the property. Diaphragm and possibly mercury cells produced chlorine for use in the manufacture of paper at the adjacent pulp mill. Most of the onsite structures were razed and buried on site in the 1960s. The property is currently vacant and owned by the bankrupt Pulp and Paper of America, LLC.

Since 1997, various site investigations have determined that there is soil contaminated with mercury at concentrations above DES’s soil standards. Site groundwater also exceeds the Ambient Groundwater Quality Standards for mercury, lead, arsenic, carbon tetrachloride, chloroform, and dichloromethane (methylene chloride). Elemental mercury has been observed in the bedrock fissures along the Androscoggin River located directly adjacent to the site.

There is currently a fish consumption advisory for the Androscoggin River from Berlin downstream to the Maine border due to elevated concentrations of dioxins (DES fact sheet on “Mercury and Other Pollutants in Fish”). All populations are advised against consuming any fish from this portion of the river. People who disregard the advisory and eat fish caught in this segment of the river could be exposed to contaminant levels that exceed safe eating guidelines.

In 1999, Crown Vantage Paper Company, in preparation for sale of said property to Pulp and Paper of America, conducted closure activities intended to isolate contamination at the site from the surrounding environment. The remaining cell house building was demolished and disposed on-site, a slurry wall was constructed on two sides of the property, and an impermeable cap was constructed over most of the property to inhibit rain from percolating into the area containing demolition debris and other contaminated media. However, water continues to flow from a drainage pipe from the capped area to the river, indicating that groundwater seepage into the capped area is still occurring. Attempting to address the mercury seeping through bedrock fractures into the Androscoggin River, grout was injected into some of the fractures and visible mercury was collected from the river and its bank. Despite these response activities, mercury continued to be found in the Androscoggin River adjacent to the site.

Between 1999 and 2006, the New Hampshire Department of Environmental Services removed approximately 140 pounds of mercury and mercury-containing debris and sediments from the river and its banks.

The city of Berlin established a Reuse Planning Committee in December 2007, as a result of a redevelopment grant awarded by EPA, to evaluate the reasonably anticipated future use(s) for the site that are intended to enhance the evaluation of remedial alternatives for the site. The committee findings were summarized in a December 2008 final report suggesting that the anticipated future use at the site would be light commercial combined with recreation/heritage corridor functions.

The site was listed on the National Priorities List (Superfund) in September 2005, making cleanup activities eligible for federal funding. The first stage of the Superfund process, the remedial investigation (RI), began in September 2006, with EPA conducting limited sediment and surface water sampling in the Androscoggin River. EPA held an RI-kickoff meeting with their selected Remedial Action Contractor, Nobis Engineering Inc., in July 2007.  However, the full-scale RI field activities did not begin until summer 2009, and concluded in 2012.  The RI Report was finalized in March 2014.  A public meeting was held in Berlin on May 29, 2014 to present the findings of the RI. 

The Feasibility Study Report, which utilizes the data collected in the RI and associated risk assessment to evaluate a range of remedial options for the site, is forthcoming following the collection of additional characterization data that will help to refine the feasibility and costs of remedial options involving off-site disposal.

NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

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