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Olin Corporation (Macintosh Plant)

Olin Corporation (Macintosh Plant)
EPA ID: ALD008188708
Location: Macintosh, Washington County, AL
Congressional District: 01
NPL Status: Proposed: 09/08/83; Final 09/21/84
Project Manager
Site Repository:
Mcintosh Town Hall
Commerce St.
P.O. Box 385
Mcintosh, AL 36553
Documents:About Adobe Portable Document Format

Site Background:
The Olin Corporation McIntosh Plant site is located approximately 1 mile east-southeast of the town of McIntosh, in Washington County, Alabama.  The Olin main plant and associated properties cover approximately 1,500 acres.  From 1952 until 1982 Olin produced chlorinated organic pesticides, chlorine, caustic soda and sodium hypochlorite at the site.  Presently, Olin produces chlorine, caustic soda, sodium hypochlorite and blends and stores hydrazide compounds at the site.  Releases of mercury and organic chemicals have contaminated the shallow groundwater beneath the site.  Discharges of wastewater containing mercury have contaminated wetlands adjacent to the Tombigbee River.  Approximately 500 people live in the area of the site.  Everyone in the area utilizes groundwater as a source of drinking water

Cleanup Progress: Threat Mitigated by Physical Clean-up Work
The Olin McIntosh plant is both a Resource Conservation and Recovery Act (RCRA) facility and a National Priority List (NPL) site. Starting in 1984, Olin has clean closed 9 RCRA hazardous waste management units at the site. One RCRA unit has been closed with waste left in place. In 1987, Olin started treating contaminated groundwater. In 1990, under a Superfund Administrative Order on Consent, Olin removed from the site 11,407 tons of hexachlorobenzene contaminated soil.

On December 16, 1994, the Agency issued the Record of Decision (ROD) for the final clean up of Operable Unit One (the 60-acre main plant area). On June 8, 1995, Olin agreed in a Consent Decree to develop the remedial design and conduct the remedial action for the plant area. When this Decree was presented to the U.S. District Court, District Judge W.B. Hand ruled that the Superfund law is not retroactive and in this case was unconstitutional. Judge Hand dismissed the government's complaint and denied the motion to enter the Decree.

On July 26, 1996, the Agency issued a RCRA Section 7003 Administrative Order requiring Olin to develop a remedial design for the plant area. On March 25, 1997, the U.S. Eleventh Circuit Court of Appeals reversed Judge Hand's decision.

The final Remedial Design for Operable Unit One (OU-1) was approved on September 29, 1998. The construction for the Remedial Action for OU-1 began during the spring of 2000 and was completed in August 2001.

The first five year review of the OU-1 remedy was conducted in 2005 and the Five Year Report was issued in early 2006.  This review found the OU-1 remedy to be protective of human health and the environment.  A copy of the report can be found in the site repository. 

Olin has implemented the OU-1 remedy. Work at OU-2 is ongoing. In 1994 and 1995, Olin collected additional data to better assess ecological risks and more adequately evaluate remedial alternatives for OU-2. These data were incorporated into a 1995 Ecological Risk Assessment and a 1996 OU-2 FS.  The ecological risk assessment for OU-2 identified potential ecological risks associated with OU-2 sediments. The constituent of concern in sediments and biota is mercury. Inorganic mercury undergoes methylation in sediments to form the more biologically active methylmercury.

In 2006, Olin constructed a berm with a gate around OU-2 as a full-scale treatability study. The treatability study’s intent is to trap flood waters with suspended solids from the Tombigbee River during flood events to enhance sedimentation in OU-2, thereby enhancing natural capping of the sediments. Various media samples will be collected over the three-year ESPP evaluation period to assess the effectiveness of the enhanced sedimentation as a remediation alternative. Olin will also conduct additional treatability studies to achieve remedial cleanup objectives.

For information about the contents of this page please contact Brenda Lane

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