Results from St. Paul Minnesota

St. Paul had been using a blended phosphate product to get below the action level for lead without success. In early 2000, the existing contract ended and a new vendor was selected. In May 2000, the old product was shut off and feed of the new product began. The new product evidently had a slightly different formulation, for shortly after initiating use of the new product, there were coliform outbreaks throughout the city. The phosphate product was shut off. Disinfectant levels were increased and bacterial control was reestablished. After approximately three weeks, the phosphate product was reintroduced. Again, the bacterial control was lost, so once again the phosphate product was shut off.

In October 2000, feed of AS-8150 was initiated.

Because it failed to meet the EPA action level for lead, St. Paul had been replacing lead service lines. Under this program, St. Paul was charged with replacing 1650 lead service lines per year. The cost to replace a lead service line in St. Paul ranges from $1,800 to $2,000. Replacing 1650 lines would cost approximately $3 million. This program is designed to last 14 years, so the total cost to St. Paul for lead service line replacement would be approximately $42 million.

A round of compliance samples was taken in December 2000, and the action level was met. A second compliance round of samples was collected in April 2001, again with passing results. After passing a second consecutive round, the Minnesota Department of Health was able to write a letter relieving St. Paul of the obligation of lead service line replacement. Not having to replace lead service lines saves St. Paul in excess of $2.5 million per year. A very significant benefit is not being required to conduct education programs advising residents of precautions to take with drinking water to avoid large amounts of lead. A third compliance round was collected in November 2001 with passing results.

St. Paul, MN 90th percentile graph, 1992 to 2004

St. Paul, MN full optimization graph, 1992 to 2004

Results from other water districts

Hibbard School, Rexburg, ID

This school in Eastern Idaho has its own well that provides drinking water for the school. The lead levels measured from the drinking fountains were as high as 120 PPB. This was the worst of all situations because little children were drinking water with high lead levels. ASI determined the treatment of the school could be done in a different fashion since it was not in use during non-school hours. Therefore treatment was initiated by mixing 4 ounces of AS-8150 into 40 gallons of water and pumped into the distribution system. At this concentration, the solution is quite turbid. Drinking fountains and faucets were operated until the turbid water came out, and then shut off.

The solution was allowed to sit overnight. Early the next morning we opened the faucets and drinking fountains to purge the system. Clear water quickly returned. Treatment was initiated at a maintenance dosage level of 0.2PPM of AS-8150. Six months later, samples were taken and the results were very encouraging- 4of 6 drinking fountains had non-detectable levels of lead, one had 5 PPB and the other had 7 PPB.

Northfork Homeowners Association, Rexburg, ID

This small housing development with 16 connections had elevated levels of lead and copper in their water. They had been threatened with fines by the Idaho Department of Environmental Quality. We initiated treatment and the lead levels were significantly reduced. The copper levels took a longer time, but were brought under control.

Beeline Water Association, Bonners Ferry, ID

This small system in Northern Idaho monitors two houses The results had been 78 and 65 PPB prior to treatment, and were non-detectable and 6 PPB with 9 months of AS-8150.