Options for healthier Puako reef spelled out
Residents now have a better idea of the cost of protecting water quality and ensuring healthy reefs at Puako Bay.
The cost to build private aerobic wastewater processing systems would run about $6 million for Puako residents, and a sewage plant would be $9 million, according to an engineer’s study completed last month. The report by Aqua Engineering — which favors the building of a treatment plant — also contained a study of the possibility of a $9 million to $10 million collection system that would link Puako homes with the Mauna Lani treatment facility.
But with federal grants available, the price is right, said George Fry, a board member of the Puako Community Association. Fry estimated the average homeowner would be out-of-pocket about $134 a month over 20 years to pay for a private treatment plant.
Residents, researchers and reef protection groups are trying to find ways to reduce human pollution impacts on the reef, where more than half of the corals have died during the past four decades, according to the Nature Conservancy. Puako Bay has about 160 homes and an estimated 60 to 70 cesspools along 2.5 miles of shoreline.
But there is no consensus yet in the Puako community on which course to take, and at least one resident disagrees with the study’s methods and conclusions.
The Aqua Engineering study for the Coral Reef Alliance found that aerobic treatment units could be installed more quickly than other options. But the systems require upkeep and do not remove bacteria and pathogens. While a private treatment plant has a longer timeline, it removes the most nutrients. The option of connecting to Mauna Lani was most expensive and would require permitting and collaboration with Mauna Lani, the study found.
The Coral Reef Alliance has just sent out a summary of the report and a survey card designed to gauge homeowner reaction to the three options, Fry said.
“I think this will be the first real test if we can get support for this and proceed,” Fry said. “If the community is behind this, there’s a good chance of getting it done.”
A 2014 study by the Nature Conservancy found a link between poor coral health and groundwater being discharged into the reef along the bay. The study found high levels of enterococcus bacteria in shoreline waters, either from human sewage or animals. Coral growth anomalies were also highest where nutrients like nitrogen and phosphates from groundwater were elevated, particularly at the Puako boat ramp and Waialea Bay.
Additionally, researchers with the Hawaii Institute of Marine Biology, found the reefs at Puako were overgrown with red filamentous algae compared to other areas of the coast. Ongoing microbial source tracking by ecologists from three universities will better trace human sewage hot spots and land-based pollution sources.
But resident Phil Hayward said the time for action was years ago.
“It’s really depressing to see 20 months wasted on what should have been a two-month inquiry,” Hayward said. “All local wastewater professionals I had spoken with two years ago agreed the only quick feasible plan for water quality improvement via cesspool replacements was ATUs.”
Hayward said a sewage plant is costly, has unknowns associated with permitting, and would take years to build. Instead, individual homeowners should be installing aerobic treatment units priced at around $30,000, Hayward argued. The total cost of putting the units where they’re needed would likely run about a third of the cost of a treatment plant and could be undertaken without forming an improvement district, Hayward said.
He challenged the math in the Coral study, saying ATUs could be installed at 100 homes for about $3 million. The reported $300 monthly maintenance cost for ATUs is also unrealistically high, he said.
“The coral reef in Puako is a national, state, county treasure,” Hayward said. “We really are not protecting it, even when the studies show its decline and human waste is shown to be detrimental and present, largely due to untreated waste from cesspools. It makes me so sad.”
Puako Community Association member George Robertson said he prefers building a plant that gives the community control over the treatment process to assure the reef is truly being protected.
“In my personal opinion, ATUs aren’t a good option,” he said. “They don’t last too long, they don’t function well unless they’re properly maintained, and they’re expensive on a monthly basis to maintain.”
The Puako-Mauna Lani reef is one of the most extensive fringing reefs on the island. NOAA’s Coral Reef Working Group declared the bay a priority in 2012. Hawaii Coastal Zone Management has also designated the bay a special management area.