The genesis of Tri-TAC in helping to formulate environmental policy and  providing technical support began in the early 1970s when Tri-TAC was  formed to advise the State Water Resources Control Board on regulations  pertaining to the California Clean Water Bonds. Since that time, the scope  of Tri-TAC's interests have diversified to encompass broader water quality  and ecosystem protection issues, biosolids management issues, air quality  management issues, and cross media transfer issues.  Tri-TAC is broken into three technical committees (Air Committee, Land Committee, and Water Committee) to address a large number of issues each year.

Tri-TAC's membership includes representatives appointed by the three  sponsoring associations and other at-large members drawn from small and  large wastewater agencies and consultants. The membership is balanced to  provide technical expertise and perspectives from both the northern and  southern parts of the state. Thus, Tri-TAC's members consist of a broad  cross-section of the wastewater community representative of most of the  sewered population of California.