The State of Iowa is gradually building information on the quality of public water supplies in the state. Dennis Alt oversees the effort for the Iowa Department of Natural Resources and compiled the latest report covering 1999. He says they don’t have enough data to give a long-term grade, but he says recent information is positive. Alt says nitrate and coliform bacteria are the two biggest sources of contamination for Iowa’s public water supplies. The state keeps track of those suppliers who provide water to 25 or more people. He says the number of public water supplies with contamination problems decreased from 198 in 1998 to 172 in 1999.There are several environmental factors that can affected the amount of contamination, so you can’t say there’s been a long-term improvement. One thing Alt does know is that contamination problems in Iowa haven’t been deadly. There have been no deaths attributed to public water systems for at least 20 years.Water suppliers are required by federal officials to take regular samples of their product to test for problems. Alt says 83-percent of the water suppliers did NOT have any major monitoring violations in 1999. Alt says 95-percent of those who failed to take the samples at the proper time did correct the problem with follow-up samples. Alt says Iowa has a good supply of water. He says it’s tough to make comparisons to other states.as some states rely more on surface water supplies, which Iowa does not. He says surface water supplies are more prone to contamination and make it tougher on those states to comply.