The City of Fairfield operates its own laboratory at the water treatment plant to test the water at various stages of the treatment process and in the distribution system. This insures that the water that is produced is safe and of the highest quality. It also fulfills the daily testing requirements of the Ohio Environmental Protection Agency (OEPA), which are reported to OEPA monthly. The laboratory and its two laboratory analysts are certified by the OEPA for chemical and bacterial testing. After initial certifications are received, the laboratory and its staff are required to recertify every three years. All plant operators and relief operators are also certified by the OEPA to run required process control testing.