Jones Street Remediation

2020 Dredging Remediation Objectives

The objectives of dredging activities are to:

• Remove sediment from the Manistee River to address potential impacts from historical MGP operations.
• Complete the work in a manner that is protective of people living and working in the vicinity of the site.

2020 Dredging Remediation Design

In accordance with Natural Resources and Environmental Protection Act, Part 201 of Michigan’s environmental regulations, Consumers Energy is planning to implement a remediation project to address sediment potentially impacted by historical MGP operations through dredging. The remediation work will be completed along approximately 1,400 feet of the Manistee River (500 feet upstream and 900 feet downstream of the US-31 Bridge). The remediation activities planned will include:

• Pre-construction activities (e.g., site clearing, staging equipment, support area construction).
• Installation of soil erosion and sedimentation controls on land, and turbidity curtains and absorbent booms in the river.
• Dredging approximately 16,000 cubic yards of sediment.
• Removing water from the sediment, then treating and discharging water from the sediment through an approved workplan or permit.
• Disposing of sediment in an approved landfill offsite.
• Installing clean backfill in the river outside of the navigational channel.
• Installing armoring along the bank in the project reach to protect the ISS monolith completed in 2018 and 2019.
• Restoration work on land in areas disturbed by the work.

2020 Dredging Remediation Permitting

The project will require permits from federal, state and local agencies. Anticipated permits to be submitted for the site are listed below:

• Joint Permit Application
• Water Treatment
• Soil Erosion and Sedimentation Control

2020 Dredging Remediation Schedule and Updates

Mobilization and site preparation activities are scheduled to begin in spring 2020; dredging is scheduled between late April and June, with any necessary backfilling also in June to July; bank restoration and upland restoration of 2018-2019 ISS work in July and August; and, final site restoration and demobilization anticipated in September.

ISS Remediation Objectives

The objectives of the remediation activities are to:

• Address the potential direct contact exposure pathway for MGP-related impacts.
• Address MGP constituents in soil that may impact groundwater venting to the river.
• Complete the work in a manner that is protective of people living and working in the vicinity of the site.

After the remediation work is completed on the site and along the riverbank, the site and adjacent area will be returned to pre-remediation land uses.

ISS Remediation Design

In accordance with Natural Resources and Environmental Protection Act (NREPA) Part 201 of Michigan’s environmental regulations, Consumers Energy plans to implement a remediation project to address soil impacted by historical MGP operations using a remedial technology commonly known as In Situ Stabilization/Solidification (ISS). ISS involves encapsulation and/or destruction of MGP impacts within a solid material. Solidification is accomplished by mechanical processes and by a chemical reaction between the impacted material and solidifying reagents to form a low-permeability solid. Stabilization is a reaction with chemical amendments to change the form of contaminants to reduce its mobility.

The remediation activities planned for the former Manistee MGP are generalized in the sequence diagrams below and will include:

• Removal of equipment from onsite treatment shed and demolition.
• Installation of soil erosion and sedimentation controls.
• Mechanically excavate the top 15-feet (approximately 22,000 cubic yards) at the site and temporarily stockpile for reuse as backfill material (pending confirmation from testing).
• Implementing ISS to treat and solidify approximately 49,000 cubic yards of upland and bank soils.
• Disposing of any impacted groundwater and soil in an approved landfill offsite.
• Installing armoring along the bank in the project reach to protect the ISS monolith.
• Restoring the remediation area.

ISS Remediation Permitting

The project will require permits from federal, state and local agencies. Permits that have been submitted for the site are listed below:

• Joint Permit Application
• Soil Erosion and Sedimentation Control

ISS Remediation Schedule and Updates

Site preparation activities are scheduled to begin in spring 2018 and will include clearing trees and shrubbery from the site, installing security fencing around the work area, installing soil erosion and sedimentation control measures which includes sheet pile cofferdam in the river, establishing traffic control measures for vehicle and pedestrian traffic (if necessary), and mobilization of equipment. Excavation and ISS activities are planned between May and September 2018. Site restoration activities are to be substantially completed in fall 2018.