Nordhorn Lake is comprised of three cells that flow from the right (east) to the left (west).  The cells total 3.8 acres, holding 8,282,568 gallons of pH 3.5 water. (Enlarge Plan - Acrobat® Reader format)

	Engineers traveled over all the lakes using a depth finder and GPS (Global Positioning System) gear to produce the contour, acreage and volume maps.
Engineers Measure Lake Depth
		Neutralization of Cell #1 began in April 2001 using calcium hydroxide slurry donated by Airgas of Evansville Indiana.  The tanker truck delivers 5,000 gallons of slurry, produced as a waste product from acetylene gas production, which has pH of 12.3 and 3,500 ppm of alkalinity.  This cell had a pH of 7.35 and 18 ppm alkalinity by October 2001.
Tanker truck delivering slurry	Slurry flowing into lake
Slurry plume	Slurry plume close-up
	Project advisor, Jack Nawrot, Senior Scientist at the Cooperative Wildlife Research Lab at Southern Illinois University at Carbondale, Illinois, describes the project to Pride Graff, head reporter of the Petersburg Press Dispatch.
Jack Nawrot and Pride Graff
		To neutralize AMD draining into Cell #2, a ground water recharge trench was excavated.  Large rock rip rap was added, 25 tons of Code L, a commercial source of alkalinity, along with 15 tons of calcium hydroxide (acetylene waste) was added to the trench.   A trail was improved to support tanker traffic for the eventual addition of calcium hydroxide slurry from Airgas.    When Cell #2 becomes alkaline, water will be pumped from Cell #2 into Cell #3, thereby minimizing land disturbances to the aesthetically pleasing lake cells.
ground water recharge trench	Limestone rock
More neutralizing material	Neutralizing Material in place