4.3.4. Targeted Science Studies

With an increasing emphasis on providing decision support for SWP operations since 2006, the MWQI program has commensurately placed a decreasing emphasis on targeted science studies in recent years. In spite of this shift in priorities, several important studies have been conducted by the MWQI program (some in collaboration with outside agencies and/or consultants) during the RTDF years; these are listed chronologically in Table A2 along with relevant citations to illustrate the breadth of study. The MWQI program additionally provided support to two key studies that examined wastewater discharges as sources of NDMA and NDMA precursors in the Delta [22,131].

**Figure 4.** Representative fingerprint charts for Clifton Court Forebay using the DSM2 model. Sources tracked by the model include seawater intrusion (Martinez), in-Delta agricultural return flows (Delta), Cosumnes and Mokelumne Rivers (East), San Joaquin River at Vernalis (SJR), and Sacramento River at Hood (Sac). Symbols show the observed concentrations at these stations.
