 Recent estimates indicate that the total potential supply of potable water on Maui is around 476 million U.S. gallons (1,800,000 m3) per day, virtually all of which runs off into the ocean.Water for sugar cultivation comes mostly from the streams of East Maui, routed through a network of tunnels and ditches hand dug by Chinese labor in the 19th century.In 2006, the town of Paia successfully petitioned the county against mixing in treated water from wells known to be contaminated with both 1,2-dibromoethane and 1,2-dibromo-3-chloropropane from former pineapple cultivation in the area ("Environment Hawaii", 1996).