A cesspool or septic system does not present the same threat as urban surface runoff, experts say, but they can be large sources of contamination without proper maintenance.
There is an estimated 8,000 existing cesspools still in use on Kauai, according to Lori Vetter, the Wastewater director for the state Department of Health. Around 4,395 households are now using septic units.
“Unfortunately, my cesspool data is an estimate due to some of the cesspools being replaced with septic systems, and there may be some duplication in our records,” Vetter said. “There are also many homes on Kauai that do not have any records of their cesspool on file with the Department of Health.”
Sewer service is provided to 4,189 accounts through county wastewater treatment, Vetter added. Another 3,140 receive sewer through Princeville Utilities, with 1,057 through the Poipu Water Reclamation Facility, and 1,300 more with Puhi Sewer and Water Company, according to Grove Farm.
On-site cesspool and septic systems are the “Wild West” of the water treatment world, said Dr. Roger Babcock, a professor in civil engineering at UH Manoa. However, when septic systems are inspected and maintained properly they are nearly as adequate as sewer.
“On site treatment has always been a valid solution and up to 40 percent of American households run on individualized systems,” Babcock said.
Sewer systems are cost prohibitive for island counties when construction and operation can cost “a million dollars a mile,” Babcock said.
Septics are a substitute. It allows bacteria to break down biodegradable waste into cleaner effluent that exits through filters into a leach field. The non-biodegrable sediment collects on the bottom and needs periodic pumpings that depend on use, maintenance and rainfall.
Cesspool designs
Cesspool designs vary, but most are deep holes where untreated wasted is allowed to leach out naturally. During high water incidents, the concern is that runoff from many cesspools will back up and cause pollution to the waterways.
The Hawaii Source Water Assessment and Protection Program Update and Maintenance guide establishes leach field zones to protect the vulnerable areas of any given location. It is used to determine where feed lots, sewage discharge or chemical and petroleum tanks are placed.
Studies show there is less bacterial pollution from cesspools and septics from high water events, Babcock said. Sediment becomes diluted with water, and the bigger threat to fresh water and ocean contamination comes from urban surface runoff from trash, oil, agricultural chemicals and fertilizers, animal waste and carcasses.
Septic becomes a threat after a poorly maintained system stops working properly, Babcock said.
Kauai’s numbers
A recent DOH study found two-thirds of Kauai home septic systems are in “good” or “functioning” condition. A third were “failing” or “would fail soon” for not pumping within two years.
“The worst finding was that 80 percent of units were not being maintained at all,” Babcock said. “In general, there are no alarm bells to ring, but the studies do show there is a need to manage it better.”
The DOH currently approves a household septic instillation plan, and the regulation ends at that point.
The state Legislature turned back bills this past session that would have helped low-income households upgrade to improved septic systems. Another would have funded the DOH to manage pollution from nonpoint sources and individual wastewater systems.
The home permit attempt has failed more than once, Babcock said, but it returns each session because septic systems continue to be “ticking time bombs.”
When effluent reaches back into the home it can become a health hazard. Depending on conditions and the pathogens present, when bacteria comes in contact with skin, it could cause an infection or virus.
Sarah Park, MD, FAAP, an epidemiologist and chief of the state Disease Outbreak Control Division, said that DOH infectious disease surveillance programs do not currently track illness or deaths linked to cesspool or septic systems.
Cleaning costs
The cost of repeatedly pump out a failing system is expensive. Some systems are working but are just vulnerable to high water events.
Local pumping services have raised their rates after a county discharge fee increase earlier this year. The prices increased $25 on average and range from $325 to $475 depending on difficulty of access, size of the tank and distance to the residence. Harry Snodgrass of Princeville said he paid $250 per pumping for years until his provider went out of business. He now pays $475 and must pump every few weeks during the rainy months.
“That is an enormous cost for someone on a fixed income, Snodgrass said.
Pumping companies discharge their tanks at wastewater treatment stations in Hanapepe, Eleele, and Lihue. They pay $30 more per 1,000 gallons of cesspools effluent; and $210 per 1,000 gallons for septics.
County Wastewater Management Division Chief Edward Tschupp, said the increase followed a rate study. Cesspool customers already pay what it costs to treat that type of wastewater, but septic customers do not and the rate adjustment is gradual. Still, without incentives, residential customers would not transition from cesspool to septic systems, or from septics to aerobic systems, until required by ordinance, said Kamaile Chand, an administrator for Hawaii Pacific Trenchless in Kapaa.
“The design and installation process includes engineering and can run from $10,000 to $20,000 depending on the type of system,” Chand said.
