Friday, March 27, 2009

Water Dissolves Schedules

Up north near the source of the Mississippi River, up around Fargo, it's apparently flooding or close to flooding. Down at the south end of the river, my territory, swamp-thing country, incessant rains are flooding us out, too.

As I've mentioned, I'm managing the removal of about 10,000 tons of creosote-contaminated soil from a site in Jena, Louisiana. Although it's probably the largest project of this kind that I've ever managed, I wasn't there this week, but the work is going on without me. On my last day on site, back on Friday the 13th, it rained, and that rain continued through the weekend. Long story sort, the hole that we had excavated filled up with 100,000 gallons of rainwater. The picture above is from Monday the 16th.

We scratched our heads wondering where all that water came from. Sure, it rained hard, but enough to fill a 100,000-gallon excavation? A rainy weekend usually doesn't fill a swimming pool. Some water probably entered the hole by overland flow, despite our efforts to divert that flow with berms, and some might have entered through soil seepage and a rising water table. Whatever - we still had a lot of water to get rid of.

The sewer authority wouldn't take it (we asked), and we couldn't discharge it to surface water without a permit (not that it would have been a good idea, anyway, because of the contamination). The landfill was willing to accept it, but they would have to mix it with flyash to solidify it before they could dispose of it, making the landfill option prohibitively expensive.

We wound up mixing the water ourselves with the soil that we were shipping to the landfill anyway - not enough to make it a runny, soupy mess, but enough to get rid of it by so many gallons per truckload. After a week of pumping, mixing and hauling, we had managed to get rid of all the water and we filled the hole back up with clean fill.

However, while we were doing this, the rest of the crew was excavating another area of the property. This provided us more soil for mixing and also kept the project progressing. However, rain hit again this week, and despite even more vigilant precautions (berms, diversion ditches, plastic sheet covers, etc.), now the new hole has an additional 100,000 gallons of water.

One step forward and one step back. The rain came down so hard - and for so long - that the crew was forced to stop work for three days. We won't know the full extent of damage until we return on Monday. I'm going back there personally to assess the damage.

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