Device halts concrete by-product
Representative field tests ‘Slurry King’ in Havasu area

Concrete slurry is the inevitable by-product of most construction projects, formed from a mixture of concrete dust and water. Federal and state environmental regulations call for it to be disposed of safely or recycled, but according to Dave Tomlinson, a field representative for DT Equipment, that’s not often what happens at the end of a construction project.

Opening up a binder, he displayed photo after photo of contractors dumping thousands of gallons of concrete slurry into waterways in California, photos that had been taken clandestinely by environmental activists. “This is how some contractors get rid of their slurry,” Tomlinson said.

The result can be serious harm to wildlife. The lime in concrete is alkaline, and can raise the pH level of water to the 11-13 range, which is highly toxic to fish, birds, insects and plants. A single slurry dump in a stream can kill off all life for years.

Tomlinson was in Lake Havasu City this week testing out a device called the Slurry King, which captures slurry created during concrete cutting and polishing (water is used to cool the blades and control dust). The device creates a closed loop, cleansing the water and recycling it for re-use in concrete cutting. The concrete dust can then be taken to a concrete recycling center and eventually reused for construction.

Tomlinson said he was field-testing the device and gathering input from local contractors. He said it would eventually cost around $30,000.

Most of the contractors he spoke to locally were unaware of the problems associated with slurry dumping. “They didn’t know it was a real issue,” Tomlinson said. “They didn’t even know about the problem of the pH.”

Arizona does not have the same problems with slurry dumping as other, wetter states such as Washington, Oregon and California. But slurry dumped in a wash near the city could easily be swept into the already-stressed Colorado River, causing damage to fisheries and other wildlife.

“It’s really such a straight shot to the lake, it’s really something that should be looked at,” Tomlinson said.

Mark Shaffer, communications director for the Arizona Department of Environmental Quality, said his department would consider improperly disposed of slurry illegal dumping. “That’s an illegal dumping violation,” he said. “Once it solidifies, that would definitely make it a violation.”

Shaffer said that concerns had been raised at a recent forum on illegal dumping in Yuma about contractors cleaning out concrete mixers in washes and other desert areas. The diluted concrete mixture can leave a permanent blight on the landscape, Shaffer said.

“It can create a platform for more illegal dumping,” he said. “People see it, and they think it’s OK to dump there.”

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