So the town's water gets infected, people drink it and start going crazy. The film starts brilliantly with a crazy guy walking onto a baseball pitch holding a shotgun. Its very tense, but sadly very shortlived. After that, the film is just cliche after cliche right to the end. I lost count of the number of times one of the main characters is saved from death right at the last second (to prove I'm not making it up - here's four examples straight away: his wife on the bed in the 'hospital', in the room with the knife in his hand, his wife in the truck with the revolver, the part in the truck garage).
After the first couple of times, all the tension is lost, in a film that needs tension to keep us gripped. It's not a zombie film, but does borrow from a lot of the techniques used. The sad thing is, without the tension its all just a bit laughable. The most cringeworthy part is the very end with the satellite zooming out (I won't spoil it, but you will be able to predict what will happen after about 20 minutes anyway). I'd recommend borrowing this, but be warned that you're not going to witness anything beyond average.