Clearance of Beach Water Contamination after 48 Million Gallon Sewage Spill in Hawaii: Reliability of Culture Assay for FRNA Coliphages and PCR Assay for Bacteroides

Heavy rains caused the discharge of 48 million gallons of raw sewage into the Ala Wai Canal. This canal discharges out to sea near popular beaches. The Department of Health closed the nearby beaches (Waikiki, Magic Island, Ala Moana) based on the C. perfringens state water quality standard rather than the enterococci U.S. Environmental Protection Agency standard. This caused the public to be confused and distrustful. The University of Hawaii monitored the same beach sites for more sewage specific microorganisms (F+ coliphages by culture, human specific Bacteroides by PCR). The results showed that the beaches were contaminated with sewage two days after the sewage spill ended but had been cleared by the fourth day. These results supported the Department of Health's decision of opening the beaches six days after the end of the sewage spill. The heavy rains that caused the sewage spill also diluted and transported the sewage out of the canal and out to sea.