This is an Admiistrative Order (AO) issued on November 28, 2006 by US EPA Region 9, Water Division, Drinking Water Office, against the US Dept. of the Navy - Naval Air Facility (NAF), El Centro, California, and KRB, Inc., a federal government contractor (KRB, Inc. is operator of the NAF drinking water treatment plant). The present AO was issued for exceeding the total trihalomethanes (TTHMs) standard under the Stage 1 Disinfectant and Disinfection Byproducts Rule. Monitoring results indicate the running annual average for TTHMs is 116 ppb. The current standard in 80 ppb. The water system serves 4000 persons and is located in Imperial County, California. The order requires Respondents to submit a compliance plan by January 31, 2007 and to be in full compliance with the total TTHM standard by December 31, 2007.