New Corps Of Engineers Plan - Use Mix Of Coal Ash & Lime To Repair Levees Along Mississippi

[hatrack]

Residents from up and down the Mississippi River came to St. Louis on Thursday to question a federal proposal that would use toxic coal ash to strengthen levees, a move that environmental groups say poses a threat to the region's main waterway.

Earlier this year, the Army Corps of Engineers announced that it was exploring the possibility of injecting a mixture of lime and coal ash — a by-product of coal combustion containing heavy metals — into 11 levees along the river, including two in the St. Louis area. The levees were built from the 1930s to 1950s from local clay, but in the last 50 years they have weakened, making the levees unstable and causing more than 800 reported slides. The plan recommended by the corps would inject a slurry of lime and coal ash into the levee slopes to stabilize them. Corps engineers say the mixture is particularly suited for filling in cracks that have formed over the decades.

But environmental groups are questioning the process, saying that putting a known toxic material into levees close to a major waterway is too risky. At a public hearing Thursday in downtown St. Louis, many underscored their worries. "I've seen a lot of yesterday's solutions that are today's problems," said Tom Ball, addressing the group. "... If this turns out to be toxic in the long run, how do we get it back?"

The coal ash and lime injection method has been effectively used to strengthen levees along a 17-mile stretch of river near Memphis, Tenn., for the last 15 years. "When the ash mixes with lime, it becomes a cement product," said Jessica Bush, a corps engineer. "... We believe it will hold the toxic material inside of it." But corps engineers acknowledged Thursday that they didn't know whether any water quality testing had been done in the Memphis area to determine whether toxic materials had gotten into the water. "When a levee breaks, this can contaminate the water," said Catherine Edmiston, of Abingdon, Ill., in Montgomery County. "... That's the water supply for many, many people."

EDIT

http://www.stltoday.com/news/local/metro/article_1478b824-1a68-5ffc-981f-239e0f9a121f.html

[Dogmudgeon]

1. "You put the lime in the coal ash, and patch it all up!"

:evilgrin:

So instead of a quick release of toxic metals (including uranium), they get a slow release.

I could understand them using this on dry land. What possessed them to use it in water?

--d!

[hatrack]

2. Well, it's usually dry land, except when the river rises . .

Then it gets a bit more . . . uh, damp.

[AtheistCrusader]

6. It's supposedly less water-permeable than most brick materials.

In addition to being incredibly strong, like high compression concrete.

Leaching might not BE an issue. (this was proposed in the days following Katrina, in a couple publications I read)

[n2doc]

3. Ye gads! Who the heck came up with this idea?

Engineers- Good at what they do but absolutely ignorant of anything that can't be calculated or modeled from a set of equations. Jessica Bush (ironic name) Sounds like someone with no real world experience.

[whistler162]

5. The wiki entry is interesting regarding Fly Ash.

http://en.wikipedia.org/wiki/Fly_ash

Might be a new use for old technology.

[BrightKnight]

4. They want to dump millions of tons of radioactive and very toxic waste in St. Louis

along the Mississippi River. This sounds like a superfund site. A failed levee would be an environmental disaster and a public safety nightmare. They have no Idea if it will leech heavy metals into the Mississippi River now or 50 years from now. What happens when they need to remove, repair, or replace it.

[XemaSab]

7. 'Cause throwing shit at it worked so well with the oil spill

:P

[madokie]

8. Fly ash is one of the ingredients in most concrete

when you order concrete from the redi-mix companies unless you specify that you want straight sack concrete you will be getting concrete that has fly ash in the mix. There used to be a redi-mix plant near here that didn't use any fly ash in their mix but they've long gone out of business. Back a few years ago, (ten or so) there was a cement shortage and during that time the redi-mix plant we used sent us concrete that was mixed with fly ash only. We were putting it in a footing and two days later when we were setting the forms for the floor the mix they sent us was still pretty soft. In that I mean you could still push a 16 penny nail into it by your hand without a hammer needed. It eventually set up and got hard as a rock but it took quite a few days before it did. None of us finishers liked finishing concrete made with fly ash in the mix but many times we didn't have any say in it. Fly ash is also use in tightening up the soil used in road beds too, sometimes. Most times they use lime for that purpose but in some cases they use fly ash.