*3.3. Interagency Delta Health Aspects Monitoring Program*

The expert panel recommendation was implemented by CDWR in July 1983 with commencement of the Interagency Delta Health Aspects Monitoring Program (IDHAMP) [36–39]. The program, initially established as an 18-month investigation (and subsequently extended), was conducted in cooperation with the U. S. Bureau of Reclamation, the City of Stockton, East Bay Municipal Utility District, Contra Costa Water District, and several SWP water contractors.

Program participants provided funding as well as technical guidance through a standing committee, with participation by other relevant parties such as the California Department of Public Health and the CSWRCB. The program initially focused on monitoring drinking water quality contaminants identified in the expert panel report [35]. Monthly samples were collected from 15 to 18 stations in areas representing urban drinking water diversions, Delta inflows, in-Delta agricultural drainage, in-Delta channels and sloughs, and the Sacramento–San Joaquin River confluence. As analytical methods became more sophisticated, new and previously unidentified water quality concerns emerged and were monitored by the program, including selenium in the San Joaquin River watershed, rice herbicides in the Sacramento River watershed, and insecticides and waterborne pathogenic protozoa (*Giardia* and *Cryptosporidium*) in both watersheds [25].
