I saw a movie more than ten years ago about people in a town somewhere in Southern California getting sick and dying from drinking water that has been contaminated with parasites! The scientist and engineers thought they got the problem solved by replacing the filtration system and there was still parasites getting through the water filtration system! Then they stumbled upon the idea to come up killing the parasites and purifying the water by making a using a powerful ozone generator. I wonder if this is the movie i saw years ago(?) I only saw the movie once. I clearly remember the movie ends where they used the ozone generator and the water came out clear of parasites! Is this the movie??

ThirstA chemical engineer struggles to find a way to kill a deadly parasite that has infiltrated a town's water supply.Let's face it: 'Thirst' is an extremely silly film, and there's a few too many movements in the plot that would have absolutely no chance of occurring in that thing called the real world (a world which I'm sure seems alien to Hollywood at times). But while 'Thirst' is very nearly mediocre, I already feel like I'm raining on the parade of the film, as it's just too hard not to become marginally interested in the mayhem that ensues. 'Thirst' is a very run-of-the-mill production, even for a television movie, but it gets by thanks to its sheer energy. It's a small guilty pleasure, but there's some downright irritating acting from a sizeable portion of the cast here, and this partially bulldozes the arid thrills of 'Thirst'.~ 6/10 ~

Thirst was a fast paced medical thriller about an all too possible threat to one of earth's most precious resources - water. All the characters are sympathetic, with the notable exception of the Mayor (there are those who would happily force cryptosporidium infected water down his throat) and the subject is handled realistically. The actors, both male and female are convincing in their roles, particularly Adam Arkin who plays Robert Miller.A movie well worth seeing

Thirst seemed to be just another disaster movie. Our hero of the story, knowing the extreme danger and threat to the welfare of his family, should have gotten them out of town before the quarantine. The plant manager was incompetent as far as politics are concerned. Why didn't he know where the $15,000,000 went? The mayor was the biggest joke of the entire movie. A liar, a swindler, a finger pointer from the beginning. Sounds like another true politician to me. He should have been run out of town on a rail.