The original Olinda Water Treatment Facility (WTF) was built in 1988, and to comply with the EPA's Safe Drinking Water Act, the upgrade to microfiltration was completed in June 1998. After treatment, disinfection is provided by a small amount of anhydrous ammonia, which is blended with chlorine to form chloramines. This facility's average daily production is 1.6 million gallons per day.
The water that supplies the Olinda WTF comes from the Waikamoi Rain Forest, and is stored in the 30 million gallon Waikamoi Reservoirs and 100 million gallon Kahakapao Reservoirs.
These reservoirs will also supply the non-potable agricultural line currently under construction. This is a joint project with the State Department of Agriculture, the Natural Resources Conservation Service, and the Maui DWS. The ag line will provide untreated surface water to farmers in Upper Kula.