SAND ISLAND (HawaiiNewsNow) - The city says it's already trucking sewage around the island. It's been doing it for years. But now a plan to haul thousands more gallons of sewage has some questioning the environmental impacts.
Nearly 120,000 gallons of sewage is processed at the Sand Island Wastewater Treatment Plant a day. But that's also over capacity and after operating like that for nearly three years it's at a breaking point.
"The big globe structure is the anaerobic digester," explained Kenny Huy, Synagro Plant Manager as we walked around the facility.
The digester is the main component. It holds the raw sewage where bacteria breaks it down. It produces sludge which then goes to the tall cylindrical storage tank nearby. The process creates a lot of methane gas. The excess methane is burned so it's not released into the environment but when tanks get too full there's a lot of rumbling and a foam backs up. That's when it knocks out the flame that burns the gas.
"You don't want to just release raw methane," said Huy. "It's safe to say if we're continually taking 20 percent over the capacity of the digester then that is a real potential we have to keep a close eye on. It's beyond its design capacity so it's not prudent to keep operating like that."
Sand Island is at 120 percent capacity. The city wants to haul 5,000 gallon truck loads of sewage to Kailua, Waianae and Ewa Beach twice a day but that concerns some lawmakers.
"I'm saying it's a matter of scope. If you have some minor trucking of sewage between areas maybe its okay," said State House Rep. Cynthia Thielen, (R) Kailua. "This is a major change where they are taking these massive amounts of sewage out. This isn't just your neighborhood cesspool truck. This is a massive trucking throughout the island."
The city has already violated the Clean Water Act and the Kailua Sewer Treatment Plant has been fined various times for odor problems. Rep. Thielen also worries about the smells at Aikahi Elementary School which is located right next door.
"We have school children that have gotten sick from the odor and gotten sick and had to be sent home. It's something that must be looked at from an environmental perspective to say does this make sense what are the secondary impacts?" said Rep. Thielen.
The city says there are some two dozen private trucks hauling sewage from Porto potties and cesspools right now. They didn't get an environmental assessment done.
The city also says it has been trucking sewer sludge to Kailua from Waimanalo and Kahuku for decades. The sewage from Sand Island would be more of the same just coming from another end.
The city lawyers are looking into the claim that they need to do an environmental assessment before hauling the sewage. If they do need an EA it could take up to a year, which would leave the city with few other options.