2) Department of Public health and safety monitors the measures taken to clean-up drinking water were effective. Trihalomethanes (THMs) at 12 counties drinking water compared before clean-up, 1 week later and 2 weeks after clean-up. Test whether clean-up system effected the THMs of drinking water. County Trihalomethanes Before Clean-Up Week 1 Week 2 21.1 19.2 18.4 24.1 22.3 21.2 14.1 12.9 12.9 18.1 17.8 17.3 15.4 15.1 14.9 16.2 15.1 15.8 7.4 7.2 6.8 7.5 6.7 6.1 14.2 13.6 13.1 10 21.3 20.9 20.4 11 9.5 9.8 9.2 12 11.9 10.5 10.1