This is an Administrative Compliance Order pursuant to the SDWA issued to the Solano Irrigation District for violations at the Gibson Canyon drinking water system. The violations involve exceedances of the running annual average MCL for total trihalomethanes for the 4th quarter of 2004 and the first quarter of 2005. There is also a violation of the running annual average MCL for haolacetic acids for the 4th quarter of 2004. The Order directs SID to submit a compliance plan within 3 weeks of receiving the AO and to return to compliance no later than September 30, 2006.