MichCon Cleanup Site

Some more background and detail:

Also along on the walk were Sandi Smith, Jane Lumm and John Hieftje, Matt Naud, Sumedh Bahl and a few other staff members, members of the North Main task force and the Environmental Commission. Hosts for the event were representatives of DTE/MichCon, the engineering firm and the contractor. All members of Council were invited, as were all members of the task force and the commission.

The “men in vests” photo shows John Hieftje (at left) standing behind David Santacroce, chair of the North Main task force. The project manager for the remediation was describing the efforts to keep any ground water from hitting the river, and the benefits to a really dry summer (the work was much easier).

The tree where the red-tailed hawk was perched will stay, as will several other landmark trees. Others have been removed. These trees have absorbed some of the pollution, and will be ground up and disposed of in an environmentally appropriate way. 

The project includes removing some deeply polluted soil. In some places, the soil removal will go as deep as 12 feet. Since the water table through this site is usually about 2 feet below grade, the engineers are planning for some serious retaining walls. The photo “muddy hole” photo shows a hole they were digging while we were there. It was about 6 feet deep, and filling up with water (I could watch the water run into the excavation). The water table is lower than usual, so they are just beginning to reach water.  

The next step is to remove any ground water as they work, and run it though a purifying system prior to releasing it into the storm sanitary sewer. The staff showed us the holding tanks and explained how the hydrocarbons would be removed and the water tested for purity before it was released. The hose coils will be linked and used to take the water from the purifying system to the storm sanitary sewer.

We walked all the way to the western edge of the site and looked at (and smelled) the outflow from the Allen Creek. In the “reflection” photo, you can see shadows of Matt Naud gesturing to Jane Lumm as he talks about the flow from the Allen Creek (which has colored this water an interesting shade) and about the need to work on the storm sewer infrastructure and identify any pollutants that are still entering the system – so they can be eliminated. “Another reflection” shows the dam with two gates open.  You can see the color of the water change from the river channel to the Allen Creek outflow.

The white foam in the photo of the muddy hole is a biologically-created material – fully biodegradable, even edible! – that is used to stabilize soil. It will also be sprayed on the materials being removed from the site, to keep them in the trucks rather than blowing in the wind.
The contractor and DTE have monitoring wells around the site to check on the pollutants. They also have some computer-assisted equipment that monitors air quality, so any volatiles unexpectedly released will cause alarms and alerts.
So, water, air and soil are all being monitored, cleaned and properly dealt with (treatment or removal) in an environmentally effective manner. The process will help ensure that this site is safely remediated.

Sabra, did anyone happen to mention if fungi mycorrhizae were considered for treatment of the soil?

Thanks to Dave for fixing my error (red lined, above).

Re #3: The MichCon staff didn’t discuss why this option was selected, or what other options had been considered, either at their (several) presentations to the City or during this tour. Although I know that soil fungi can digest hydrocarbons and help remediate spills, I don’t know enough about this site and it’s problems — some over 80 years old — to guess whether mychorrhizae would have been a viable option.

This site reminds me of the old Cliffs Dow site along the shore of Lake Superior in Marquette. Based on the extensive and expensive ongoing remediation work on that site, I would strongly urge the city never to buy this land.

Ed, without looking into it, my guess is that the chemicals that Dow left behind are a different matter than the (mostly?) hydrocarbon compounds that are in the soil at the MichCon site, but it would be worth the effort to get more details.

The Cliffs Dow site in Marquette was the site of a plant that turned wood into chemicals; the Ann Arbor MichCon site turned coal into manufactured gas. So there will be differences. I just know that the smell of creosote lingers a long, long time.

Kudos on the work of that new Chron’ reporter!

I did a little quick browsing after the mention of mycorrhizae. These are fungi which are obligately symbiotic (or one could say “parasitic” since they take carbohydrate from the plant) with green plants, most often woody plants. Some are very species-specific. That is why mushroom hunters often know to look under certain tree species for some mushrooms (many mushrooms are the fruiting bodies of mycorrhizal fungi).

My browsing turned up a couple of sites where mycorrhizal inoculation of soil was promoted to improve nutrient availability for plants, as I would expect. (Mycorrhizae make some mineral nutrients, especially phosphorus, more available to the host plant.) But I didn’t see any claims that these fungi can be used for cleanup of pollutants. Since they are obligate parasites, it seems an odd choice.

Vivienne, so a Web search for Paul Stamets. He did a TED talk on it and probably has info on his web site.

Steve, he has a number of TED talks. I listened to part of the one called “Six ways mushrooms can save the world” but couldn’t sit through all of it. He seems to be something of a fabulist. “The mycelium is sentient” “Fungi are the earth’s internet.” Admittedly in my previous life as a fungal physiologist I took a more reductionist approach, but I’d like to see some peer-reviewed study of any claim he makes.

Great photos, and thanks for all the extra details in the comments. I have gone kayaking through the Cascades a couple of times in the past month, and noticed the hydrocarbon-ish smell. It will be interesting to note how much worse it gets before they are done.

The term you are looking is “Mycoremediation” and one of the best species of fungi for use as a catalyst is Pleurotus ostreatus or commony known as oyster mushrooms [link].

A few links that will provide information: [video]
[link] [link]

Thanks for the pointer to Pleurotus. This is a “white rot” wood-rotting fungus. White rot fungi secrete enzymes that can degrade lignin because they attack polycyclic and phenolic residues. (So the rotted wood looks white with the lignin gone.) Also, they are primarily not parasitic. It makes sense that they might be useful in degrading pollutants.