Municipal wastewater plumes discharging from aquifer to ocean were detected by nearshore wading surveys at Kihei and Lahaina, on the island of Maui in Hawaii. Developed in cooperation with the Hawaii Department of Health, the survey methodology included instrument trolling to detect submarine groundwater discharge (fig. E1), followed by analysis of water and algae samples for a suite of chemical and isotopic constituents that constitute a "multitracer" approach. Following a successful proof-of-concept phase, surveys were conducted at two municipal-scale wastewater reclamation facilities on Maui, where several million gallons per day of "reclaimed water" (treated and disinfected wastewater effluent) are injected into deep wells. The main question to be answered by the study-and a topic of long-standing interest-is where and how the effluent discharges to the nearshore coastal environment.