HOW ARE WE CARING FOR HARBOR ISLAND?
Restoring a Natural Area
Restoration Plan Overview
Harbor Island has a history of industrial use and waste disposal dating back almost 100 years. The Island was built using city trash, dredge materials, and coal ash from the J.B. Sims Plant, Units 1 and 2. The Island was also home to other industrial uses before a power plant was ever built there.
To prevent disruption and potential contamination of the Grand River from coal ash materials deposited on the Sims site more than 35 years ago (and potentially from the City dump material this ash lays on in certain areas), GHBLP plans to stabilize, cap and monitor these materials.
A Challenging History
Harbor Island was not much of an island 100 years ago; it was more a delta of the Grand River that our community made into an island. Prior to the construction of J.B. Sims power plant, Grand Haven used portions of this site and other areas on the Island as a city dump for decades. River dredge materials were placed in other locations on the Island. Historical photos attest that the island had numerous other industrial uses including coal storage, distribution, and ash disposal for industries and homes in the area. When the coal plant was built in 1960, local leaders planned to use coal ash from Units 1 & 2 as “beneficial fill.”
“Ash fill from the steam plant will gradually eliminate the marshy areas on the island. Additional fill will be provided by the city dump, the boundaries of which can be shifted. ‘Made’ land of this character has infinite possibilities.”
– Grand Haven Tribune, February 7, 1958
Needless to say, more environmentally responsible practices for the handling of ash and trash have evolved since then.
About Coal Ash
The process of combusting coal to produce steam and generate electricity leaves behind a byproduct of coal ash. Also called “coal combustion residuals” (or CCR), these materials contain contaminants like mercury, cadmium and arsenic. Before environmental regulations evolved, coal ash was thought to be safe for use as a local fill material, which is how operators of Units 1 and 2 disposed of it – they used it to fill low areas surrounding the power plant. By the time GHBLP constructed Unit 3 (and retired Units 1 and 2) in the early 80s, new regulations meant that ash was only stored temporarily in a regulated on-site “impoundment” until being disposed responsibly at a licensed landfill. The impoundments used for Unit 3 have now been cleaned out of any remaining ash and will be properly closed.
When operators captured and removed fly ash, bottom ash, scrubber residues or other ash from Unit 3, the materials were first pumped into a clay lined surface holding area or “impoundment” (basically a pond or reservoir to retain the fine ash particles) until much of the water could be removed and the solid material taken to a licensed landfill. There is an additional “legacy” impoundment area used historically for Units 1 & 2 on the Sims site as well. This area, which was not engineered or lined, was used until the early 1980s when Unit 3 began operations.
Understanding the Scope of Cleanup
In preparation for the 2018 decision to schedule J.B. Sims for closure, GHBLP hired Golder Associates, a nationally recognized environmental engineering firm, to evaluate and recommend the appropriate closure of the coal ash handling impoundments along with other associated environmental issues that may arise in the demolition of the plant and the necessary remediation of the Sims site. Golder has extensive experience with environmental remediation and mitigation projects in Michigan and across the nation, including many coal fired facilities much larger than Sims.
Unit 3 Impoundments
The resulting plans called for cleaning and closing the Unit 3 ash impoundments by the end of 2020. These impoundments, engineered and built in the early 1980’s, as two separate above ground clay lined ponds were used to collect and temporarily store ash until it could be removed and disposed of at a licensed landfill. This clean-up is now complete.
Golder is reviewing analytical testing conducted following the cleanup to confirm that the ash was properly removed from the impoundment. The results will be submitted to the Michigan Department of Environment, Great Lakes, and Energy for review.
Units 1 & 2 Impoundment
The older ash impoundment shared by Units 1 & 2 was not engineered and predated environmental regulations applicable to newer impoundments such as the one used since Unit 3 became operational. This legacy impoundment was essentially a low spot on the Island used to hold ash until it could be relocated on the Island and used as fill.
Given the record high water elevations of the Grand River, this depression is now flooded with water, making the removal of any remaining ash in the impoundment difficult, requiring substantial dewatering efforts. Additionally, the ash in this impoundment lies directly on trash from the City Dump in some areas. The ash historically used for making more land on the island adds to the complexity considering state and federal ash regulations were not written for a site like Harbor Island with multiple pasts uses.
Both Golder and the GHBLP are concerned with the protection of the Grand River during dewatering and closure activities, particularly in these circumstances. This work could disturb and then potentially release materials that have been stable in place for over 40 years. With these concerns, Golder recommended collecting and analyzing water samples at three sampling points where groundwater from Harbor Island intercepts the surface waters of the Grand River. The results of these analysis indicate current conditions on the site have insignificant impacts on the Grand River.
Based on the favorable test results gathered during the 4-month study period, Golder recommended submitting to the State a request to approve a “mixing zone” allowed by Michigan law that would require continued long-term monitoring of the surrounding waters. Golder is also evaluating a program that would stabilize and minimize material disturbances to continue protection of surrounding surface waters. This program includes both capping the legacy ash impoundment and stabilizing the island fill. This more comprehensive approach solves multiple concerns from both the historical ash used as fill and the former trash dump rather than confining actions to only address the limited ash in the impoundment. This capping and stabilization approach has historically been accepted and used in other industrial applications.
A Holistic Approach
The Board of Light and Power is committed to responsibly addressing the most pressing issues at Harbor Island for the protection of the environment and our community. Currently, regulators are mostly focused on remediation of ash impoundments, but with the history of mixed uses on the island, it will be critical to think holistically about island contamination, changing water levels and the surrounding Grand River.
With the guidance of Golder Associates and our community’s best interests in mind, we are working with the Environmental Protection Agency and Michigan Department of Environment, Great Lakes and Energy to determine the best path forward.
Access to the complete documentation on this process is available to the public. We encourage community stakeholders to review this information to best understand the complicated cleanup efforts underway.