January 30, 2008
Massive Discharge of Untreated Sewage into the Ala Wai Canal (Oahu, Hawaii): A Threat to Waikiki’s Waters?
By Venzon, Nel C Jr
The world-famous Waikiki Beach, situated along Oahu's picturesque south shore, may be in jeopardy. Considered the heart of Hawaii's tourism industry, Waikiki and its surrounding environs host about 72,000 visitors per day, amounting to an estimated $3.6 billion total gross state product in 2002 (Department of Business, Economic Development & Tourism, 2003). Recent events affecting area waters, however, may have seriously compromised Waikiki's future economic productivity and, as a result, undermined one of the state's major economic driving forces. On March 24, 2006, Honolulu, Hawaii, witnessed one of its worst environmental crises when an estimated 48 million gallons of raw sewage were purposely diverted into the Ala Wai Canal over a five-day period (City and County of Honolulu, 2006). The Beachwalk Wastewater Pump Station (WWPS) Force Main, a 42- inch-diameter reinforced concrete pipe located on Kaiolu Street, had finally given way after servicing five Honolulu communities since its construction in 1964 and had ruptured after weeks of heavy rain (City and County of Honolulu).Built in the early 1920s, the Ala Wai Canal is an approximately 2- mile-long waterway that receives drainage from Makiki (1,687 acres) and the Manoa-Palolo region (6,247 acres) (State of Hawaii Department of Land and Natural Resources, 2003; State of Hawaii Department of Land and Natural Resources Division of Water and Land Development, 1992). Also, serving as an estuary, the canal receives stormwater runoff from an additional 4,099-acre region comprising Ala Moana, Moili'ili, Kapahulu, and Waikiki (State of Hawaii Department of Land and Natural Resources, 2003). As a result of this heavy and widespread use, the canal has become polluted and has deteriorated over the years (De Carlo, Beltran, & Tomlinson, 2004; State of Hawaii Department of Land and Natural Resources, 2003). Since the flow from the canal and upstream vicinity empties into the near-shore marine waters, Waikiki waters and adjacent beaches are directly affected by any form of runoff.
A preliminary report indicated that a combination of heavy rainfall runoff into the sewage system, the rupturing of an aging sewer line on Kaiolu Street in Waikiki, area ground settlement, and near-by pile-driving activities appear to have contributed to the incident (City and County of Honolulu, 2006). In addition, all four pumps had to be turned on at the Beachwalk WWPS to accommodate the increased infiltration into the collection system, creating a pressure surge within the force main. Further inspection of the ruptured pipe revealed no sign of corrosion, suggesting that the break was recent (City and County of Honolulu, 2006).
The lack of a backup line forced local authorities to divert raw sewage into the Ala Wai Canal while the damaged pipe was being repaired. "Pumping sewage into the Ala Wai Canal prevented the waste from backing up into homes, hotels, and businesses located in Waikiki and nearby areas, which would eventually flow into the canal," said Watson Okubo, supervisor of the Monitoring and Analysis Section Clean Water Branch (CWB) of the Hawaii State Department of Health (HSDOH). This strategy was part of a contingency plan established in 1996 for management of massive spills in Honolulu's main metropolitan area (Perez, 2006). Another option was to haul wastewater away to the treatment plant; however, this inefficient approach was not a match for the magnitude of the spill (Takamura, 2006). Although the spill did not drastically affect residential areas, environmental and health concerns were nevertheless inevitable.
On the same day that the sewer main ruptured, officials from the City and County of Honolulu (CCH) Department of Environmental Services Monitoring and Compliance Branch immediately conducted water sampling from the canal and shoreline stations to evaluate contamination levels. Water quality was monitored at five canal stations, 18 shoreline sites, and 10 surf sites (Hawaii State Department of Health Clean Water Branch Monitoring and Analysis Section, 2006).
"Signs were posted thereafter along Ala Wai Canal to Magic Island, Ala Wai Yacht Harbor, and other areas to warn the public of sewage contaminated water and that exposure to water may cause illness," Okubo said (see photo on page 26). CCH officials and crews also launched small boats and conducted daily monitoring of ocean currents and the flow of water from the Ala Wai drogues (City and County of Honolulu, 2006).
Although CCH did not conduct testing for pathogenic organisms, wastewater spill monitoring results revealed elevated levels of fecal coliform bacteria, enterococci, and Clostridium perfringens, which constituted a clear indicator that a potential health risk existed for individuals exposed to the contaminated water. Although fecal coliforms do not directly pose a danger to people or animals, they are generally associated with other organisms that cause typhoid, dysentery, hepatitis A, and cholera (U.S. Environmental Protection Agency, 2006a).
According to Terence Teruya, environmental health specialist for HSDOH's Clean Water Branch, "These bacteria [fecal coliform, enterococci, and C. perfringens] are used as indicator organisms. Enterococcus in particular is used because of the ease of collection, identification, quantification, and correlation with gastrointestinal illnesses. These organisms reside in every human being, so consumption/contamination is not an issue."
A study conducted by the U.S. Environmental Protection Agency (U.S. EPA) in 1986 serves as the basis for establishing enterococcus as the indicator organism (U.S. EPA, 1986). "In the study," Teruya continued, "a correlation between enterococcus and gastrointestinal illnesses was identified, suggesting that the higher the enterococcus concentration, the greater the number of swimmers who reported gastrointestinal illnesses."
According to HSDOH Administrative Rules Chapter 11-54, enterococci concentrations should not exceed a geometric mean of 33 colony-forming units (CFUs) per 100 mL for inland recreational waters and 7 CFUs per 100 mL for marine recreational waters (Hawaii State Department of Health, 2004). During the five days following the spill, increasingly high enterococci counts were observed at Ala Wai Canal sampling stations, reaching the alarming counts of an estimated 140,000 CFUs per 100 mL at the spill site on Kaiolu Street, 780,000 at the McCully Street Bridge, and 120,000 at the Ala Moana Boulevard Bridge] in water samples collected on March 29 (Figure 1).
A total of 729 records reflecting enterococci concentrations from September 1987 to December 1998 for the Ala Moana Bridge site and from April 1988 to December 1998 for the McCully Street Bridge site show geometric mean enterococci concentrations of 179.5 and 231.9 CFUs per 100 mL of water sample, respectively.
Although enterococci counts at five Ala Wai Canal sampling stations subsided thereafter, bacteria levels still exceeded the limit set by HSDOH for enterococci for 16 consecutive days following reconstruction of the ruptured pipe and cleanup of the reconstruction (Figure 2). As a result, the state health department closed affected beaches and posted additional warning signs urging the public to stay away from near-shore marine waters as well as several Waikiki shoreline stations because of high bacteria counts (Vorsino, 2006a).
The closure of the nearby beaches on March 25 and their re- opening on April 4 were also based on HSDOH's analysis of C. perfringens concentrations resulting from environmental soil sources of enterococci (Fujioka, Betancourt, & Vithanage, 2006). During this period, results of environmental monitoring and beach water sampling for FRNA coliphages by culture and Bacteroides by PCR in Roger Fujioka's laboratory at the Water Resources Research Center also showed that the beaches were contaminated for up to two days but not four days after the sewage spill had stopped (Fujioka, Betancourt, & Vithanage, 2006).
Despite such preventive measures, many beachgoers remained unaware of the extent to which sewage had contaminated shoreline waters and were disappointed that warning signs were not more conspicuously posted. "As soon as I got into the water [near Fort DeRussy and Duke Kahanamoku beaches], I noticed the foul smell, and it [the water] was brown. I could not stand it and left right away," said Ursi Schmid. Schmid had to ask the lifeguard on duty for information because of the unavailability of warning signs. Although enterococci counts exceeding the limits were measured after the spill, warning signs were not posted in the vicinity until March 29 (Hawaii State Department of Health, Clean Water Branch Monitoring and Analysis Section, 2006). "I should have been properly warned, because it involved risking the health of the general public," said Schmid, who came from Switzerland to live in Hawaii and has been swimming at the same beach for 16 years.
High enterococci levels were also detected in waters near the Waikiki Yacht Club and Magic Island, which sit on the ocean side end of the Ala Wai (City and County of Honolulu, 2006). These findings have left Hawaii residents skeptical and wary of the area. Corbin (last name not given) and Greg Terry, for instance, are longtime recreational fishermen who made use of the waters surrounding Waikiki Yacht Club and Magic Island before the incident. "We enjoyed fishing ulua [jack fish], papio, and 'owama [goatfish], and sometimes we would catch fish that weighed 20 to 45 pounds. But because of the sewage spill, we are scared to even touch the water," Terry said. Other major recreational activities, such as canoe paddling, whose practitioners normally practice on the Ala Wai Canal, have already relocated to other sites because of the massive spill. The Oahu Hawaiian Canoe Racing Association and Na Ohana O Na Hui Wa'a, Oahu's two largest canoe-racing associations, representing about 5,000 paddlers of all ages, reported that practice would not be held at the canal in 2006 because of the incident (Leone, 2006a). In addition, 11 association canoe clubs were also displaced from the canal and from Magic Island, resulting in a decline in membership, because of the fear that members might become infected from the bacteria-contaminated water (Leone, 2006a; Advertiser Staff, 2006).
The state's Department of Land and Natural Resources (DLNR) made efforts in collaboration with the Pacific Environmental Corporation (PEC) to clear the debris trap at the mouth of the Ala Wai Boat Harbor. The trap contained materials that had come down during heavy rains concurrently with the raw-sewage discharge (Antone, 2006). Located at the base of the Ala Moana Boulevard Bridge, the trap serves as the final catch point before the canal waters reach the open ocean. According to state officials, DLNR hired PEC to handle hazardous materials as a precautionary measure when it was working on waters from the canal.
Oliver Johnson, a 34-year-old Waikiki resident who fell into the Ala Wai Harbor, allegedly died one week after contracting a Vibrio vulnificus infection in his foot, a condition that was perhaps exacerbated by a preexisting history of alcoholic liver disease (Creamer, 2006). The Centers for Disease Control and Prevention (CDC) has reported other cases of V vulnificus infection, in which three of 14 people with wound-associated illnesses died; those incidents likely resulted from exposure to flood waters caused by Hurricane Katrina in the U.S. Gulf Coast (2005).
Additional concerns about the extent of possible contamination from the spill prompted further testing of the sand covering the resort-laden coastline of the south shore. Results indicated that bacteria levels on two Waikiki sites were within acceptable levels for bacteria in the water and did not pose a health risk (Aguiar, 2006). State Health Director Dr. Chiyome Fukino, however, commented that the results were inconclusive because three had been no previous testing of the sand; pre-contamination bacterial counts would be needed to provide a comparison with post-contamination samplings (Vorsino, 2006b). An independent analysis of beach sand for fecal indicator bacteria in Fujioka's laboratory at the Water Resources Research Center showed that concentrations of these bacteria were higher in sand away from the water, suggesting that the source was not related to the sewage-contaminated beach water (Fujioka, Betancourt, & Vithanage, 2006).
In addition to routine maintenance and cleanup of the debris trapped in Ala Wai Harbor waters, Natural Systems, Inc. (NSI) is currently operating a 2,000-foot demonstration installation employing a bioremediation strategy to improve water quality in the Canal (see photo on page 29). The NSI project, which started in January of 2005, utilizes planted rafts that include the akulikuli plant (Sesuvium portulacastrum), an indigenous Hawaiian plant that bears small pink flowers and attracts waterfowl (Bornhorst, 2005). S. portulacastrum grows along the coastal regions and can survive various stress conditions such as salinity, drought, and heavy- metal contamination (M.S. Swaminathan Research Foundation, 2005).
According to Chad Durkin, Malama Aina Foundation science specialist, the effectiveness of the project depends on many uncontrollable variables: "Basically, the exponential growth of beneficial bacteria communities will have the greatest positive impact on the canal ecology. This is difficult to measure, so we measure water quality as an indicator of ecological change." The photosynthetic system, which helps improve the quality of the water, is also associated with other microorganisms such as algae and bacteria, particularly the nitrosomonas and nitrobacter that interact with the hydroponic roots.
City officials claimed that the sewage discharge incident was the largest in Hawaii State's history. Previous ruptures in the Beachwalk WWPS Force Main were not as serious as the one observed on March 24, according to Department of Environmental Services spill records. The first incident, a hairline fracture at the section of the Beachwalk WWPS Force Main that was detected on February 27, 1993, was believed to have caused a spill, lasting two days, of 510 gallons of wastewater into a nearby gravity collection systems manhole (City and County of Honolulu, 2006). Another incident, which took place on January 20, 2004, yielded zero spill volume as it was contained in the Force Main vault (City and County of Honolulu, 2006). Before the Ala Wai Canal incident on March 24, 2006, a 2- million-gallon spill into Marnala Bay near the city's Sand Island Wastewater Treatment Plant on March 2, 2004, was the largest spill recorded as resulting from a sewer line break; it required three hours to repair (Leone, 2006b).
As an emergency plan, the city immediately activated the Beachwalk Wastewater Emergency Bypass (BWEB) project, which includes a 7,200-foot temporary bypass line to prevent future diversions of wastewater from the current force main (City and County of Honolulu News and Events, 2006). In addition, Governor Linda Lingle signed a proclamation on May 24, 2006, declaring Honolulu a disaster area, allowing the city to respond to the urgency of the situation and expedite pertinent administrative processes (Beachwalk Wastewater Emergency Bypass, 2006). The BWEB project is estimated to cost $20 million, including $2 million for the repair work of the March 24 break and $3 million for environmental restoration (The City and County of Honolulu News and Events, 2006).
At the time of this writing, HSDOH officials are establishing, as a civil-defense routine, an incident command system (ICS) that will delegate preparation, response, mitigation, and recovery should another massive spill occur. The ICS includes provision of public information via the local reporting system. A telephone hotline and Web site outlining pertinent details are being developed and updated daily to augment public awareness. A Wastewater Spill Response Committee, comprising government and private officials, surfers, and other individuals, has also been formed and meets on a weekly basis to address the improvement of Oahu's water quality and reduction of the impact of future spills.
Another important challenge facing HS-DOH is the development of multiple indicator organisms. "A third indicator to improve the current detection methods is highly recommended to obtain immediate results," Okubo said. "Escherichia coii and enterococci are not clearly representative of the number of fecal matter in the contaminated water." In Hawaii, rain-related high enterococci levels may not clearly indicate the presence of sewer or fecal matter in the water because elevated counts in streams are due to runoff from soil, which are permissive microbiota that allow the in situ growth of these bacteria (Byappanahalli & Fujioka, 2004).
Indeed, the catastrophic nature of the recent Ala Wai Canal incident provides an important lesson to Hawaii's state government with respect to issues that pose a profound effect on the economy and the community, as well as the environment. Pumping roughly 48 million gallons of untreated sewage into the canal was undoubtedly an incident with immeasurable consequences. A disaster of this magnitude is comparable to the largest spill in the history of the United States, the Exxon Valdez case, which spilled more than 11 million gallons of crude oil in Prince William Sound, Alaska. Ironically that incident occurred on the same date 17 years earlier (U.S. EPA, 2006b).
This environmental challenge is certainly an issue not to be ignored. If neglectedand worsened by expanding anthropogenic activities that contribute to the increasing deterioration of the canal-it potentially could have an irreversible negative effect on Oahu's south shore beaches and marine ecosystem, the state's tourism, and, most important, the future of Waikiki and those who live in paradise.
A warning sign is posted near the Ala Moana Boulevard Bridge and the Ala Wai Yacht Harbor, where water from the Ala Wai Canal empties into the open ocean. Although a floating device traps most of the debris, it is ineffective in eliminating other wastes and pollutants in the water.
The akulikuli plant (Sesuvium portulacastrum), anchored on rafts, is used in a bioremediation demonstration project to improve the water quality in the Ala Wai Canal.
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Acknowledgements: The author expresses his appreciation to Watson Okubo for providing statistical and technical information throughout the investigation for this report. He also thanks Dean E McGinnis and Walter B. Igawa-Silva for providing tremendous assistance in the preparation of the manuscript.
Corresponding author: Nel C. Venzon, Jr., Mathematics Department, University Laboratory School, Curriculum Research & Development Group, University of Hawaii at Manoa, 1776 University Avenue, Honolulu, HI 96822. E-mail: [email protected]
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