Mill River, Fairfield, CT
The estuarine portion of the Mill River in Fairfield, CT, consists of two water body segments. Segment CT-W1_005 is located from the mouth of Southport Harbor (parallel to Willow Street) upstream to Harbor Road in Fairfield. Segment CT-W1_006 begins at the Harbor Road crossing on the Mill River and continues upstream to the Sturges Road crossing of the river.
What’s New? Exide/Mill River Cleanup
What’s New? Exide/Mill River Cleanup
Within these segments, the Mill River is classified as a Class SA surface water body. In accordance with the Connecticut Water Quality Standards, as a Class SA water body, the Mill River should support a healthy aquatic and wildlife community, support recreational activities and be a resource for fishing and shellfishing. However, data for the water body indicates that these uses are not currently attained. For this reason, the estuarine portion of the river has been identified as impaired for aquatic life uses, recreation and shellfishing.
Section 303(d) of the federal Clean Water Act requires states to develop a Total Maximum Daily Load Analyses or an equivalent plan to identify the cause and sources of the impairments, set environmental goals to resolve the impairments, and implement the necessary changes. The causes of the impairments have been identified as bacteria, lead, and chromium. Information is provided below for each of these pollutants to identify the necessary pollutant reductions needed, and activities in support of those reductions.
One cause of the shellfishing impairment within the Southport Harbor is elevated concentrations of bacteria. A Total Maximum Daily Load analyses has been established by CT DEEP, and approved by EPA, to identify potential sources of bacteria to the water body, and set pollution load reductions necessary to restore sanitary quality, within the water body, such that shellfishing uses could be restored. The TMDL for this portion of the Mill River is part of the Statewide Bacteria TMDL and is specifically addressed within the Appendix for Estuary 4: Westport-Fairfield.
The lead contamination within the Mill River was evaluated as part of human and ecological risk assessments conducted by the Exide Group Incorporated, as required by CT DEEP. Risk assessments have shown that lead in the sediments is impacting the recreational use of the river due to risks from direct contact with sediments containing lead, as well as accumulation into fish and shellfish tissues, which could pose a risk to people who might eat the fish and shellfish.
In response to the contamination, a fish consumption advisory has been established recommending that people not eat Blue Crab from the Mill River estuary. The risk assessments also demonstrated that the aquatic life and avian communities were at risk, due to exposure to lead.
The Exide Group Incorporated is under order to remediate the lead contamination associated with the former Exide Battery Manufacturing facility which was located on the banks of the Mill River. The upland portion of the cleanup has occurred and the company is preparing to conduct remedial activities to address the sediment contamination.
Exide/Mill River Cleanup Project
Project Updates from Exide:
Sediment Remedial Action Plan
On October 3, 2013 the Department issued the following three documents:
1. Approval of Exide’s July 2013 Remedial Action Plan for Lead Impacted River Sediments , Mill River Study Areas I-V, Former Exide Battery Facility, 2190 Boston Post Road, Fairfield
2. DEEP's Responses to Public Comments on the Remedial Action Plan for Lead Impacted Sediments , Mill River Study Areas I-V, The Former Exide Battery Facility Project, Fairfield, Connecticut
Attachment IX – Public Comment Letters (comments 1 - 45)
Exide Group Incorporated Sediment Remedial Action Plan Revision: Dated July 2013
Discharge Monitoring Reports for the Exide Project Permit # CT0030651 are available on EPA’s website The reports are listed under the heading: Regulatory Interests.
Minor NPDES Permit Modification, dated September 17, 2014, Associated with the Improvements to the Wastewater Treatment System
Minor NPDES Permit Modification, dated November 5, 2014, associated with odor control and mitigation measures
OLISP General Permit
OLISP General Permit, Approval of Registration - October 2013
OLISP Modification Approval Letter - July 2014
CT DEEP is currently working with Superior Plating Company to evaluate and address chromium related issues within the Mill River
Content last updated on October 23, 2019