The pieces are coming together for a project to try and rid Penobscot River water of its worst mercury contamination. A pilot project could begin later this year if it receives all the necessary permits. Pollution has forced the state to urge consumers to limit their intake of fish taken from the river, which is a particular concern to the Wabanaki people.
"It's a spiritual part of their existence. It's also the source of sustenance, fishing," said Lori Valigra, a reporter at the Bangor Daily News.
Valigra details the clean-up effort in a two-part report. Irwin Gratz spoke with her about the process, which is expected to take years to complete.
Lori Valigra: The biggest amount of mercury came from a plant called HoltraChem, it was making chemicals for the paper industry in Maine. That plant was routinely discharging chemical byproducts into the Penobscot River from the 1960s to early 1970s, until the Clean Water Act came into effect in 1972. HoltraChem went bankrupt and a company called Mallinckrodt, which was one of the owners was ordered to pay for the cleanup by a judge. And it's unusual in that it's a very large settlement. It's $187 million plus another $80 million should there be additional cleanups needed.
Irwin Gratz: What makes cleaning the mercury out of the Penobscot so expensive and difficult?
Two things. One is that it's a tidal river. So the river would normally try to wash sediment and wash it down into the sea. But because it meets the ocean, the ocean is pushing it back up. And so there's an area where there's the sediment is just going back and forth with the tide during the day and that's very hard to isolate and pick that up. So in that particular area of the river, there's a trust called Greenfield Penobscot Estuary Remediation Trust that is coordinating these efforts to clean up the river. And in that area, they're going to dredge it, if they can get the permits to do that. Part of it is that there are a lot of marshy areas. And those areas are very sensitive environmentally. There are a lot of plants in there are a lot of different creatures living there. And it's just difficult to get betwixt in between everything to clean it out. So in certain areas, they're just letting the river go through and capping in certain areas. Capping means putting a layer of several inches of sand over the current sediment to keep it from touching fish or anything else. The Greenfield Trust is doing a pilot study, looking at whether or not these caps actually work. There's concern that they could be disturbed in some way and the mercury re-exposed in the river by ice flows coming down during the spring melt. And so they're looking for an entire year to see what might actually disturb these caps or not.
Is there any time period for how long the cleanup will take?
It could take the river 50 - 80 years to a wash and dilute the mercury. There are other rivers in the nation that were cleaned up in this manner. And they took an average of 10 years. So they're thinking it could be 10 but it could be a little longer, depending on what they find when they go down into the sediments.
Lori Valigra is a reporter with the Bangor Daily News. Her stories on the mercury clean-up in the Penobscot River will run in the newspaper Monday and Tuesday.