Amid legal questions and with a public informational briefing set for next month, the city is moving ahead with planning for the temporary trucking of raw sewage sludge from its Sand Island Wastewater Treatment facility to treatment plants in Honouliuli, Kailua and Waianae.

Hauling would involve three 5,000-gallon trucks making two daily runs — up to 210,000 gallons per week — from Sand Island, which is over capacity, to each of the three outlying plants. It was expected to begin by the end of the month, but officials say details still are being finalized, including test runs of one delivery per day to determine the impact of the sludge transportation.

At least one state lawmaker says a formal environmental assessment is needed before the hauling can begin. City officials, noting that the Department of Environmental Services already hauls more than 200,000 gallons of sludge per week to the plants in Kailua and Honouliuli, said the city corporation counsel is studying the request.

"If the EA is required, we’re not going to violate the law," said Tim Steinberger, city environmental services director.

The need for hauling comes as the city seeks to expand at the Sand Island Wastewater Treatment Plant, and relieve the "digester" that has reached capacity due to changes enacted in recent years with the way the raw sewage is processed.

But how that expansion happens has become an issue with the City Council, which has withheld funding for the building of a second digester and asked the city administration to examine alternative technologies.

Failure to come up with a solution could lead to a delay or moratorium on construction projects from Hawaii Kai to Halawa that require sewer lines.

"Right now, that’s kind of our very last resort and we’re hoping we don’t have to go down that road," said Steinberger, an engineer who oversees all of Oahu’s waste management systems. "We’re hoping that we can continue operating up until we get an interim-type of treatment process in place to treat this excess capacity."

The existing 100-foot-high, egg-shaped digester at Sand Island was originally designed to handle 8,000 dry tons of material each year, with a maximum capacity of 10,000 dry tons. Steinberger said the city in recent years has had to add more chemicals to treat raw sewage, "to get a better quality of the water that’s discharged." The process, in turn, leads to more sludge — the leftover material that must be detoxified and converted to compostable material.

Currently, the digester is taking in about 10,500 dry tons of sewage each year, Steinberger said.

The city had begun design and planning for a new digester and sought $26 million for it this year, but Councilman Romy Cachola worked to get the funds deleted from the budget out of concerns over the plant’s operator, Synagro Hawaii, and safety issues raised in a study about fertilizer pellets the company is producing. Council members then passed unanimously a resolution requiring the city to examine alternative technologies for treating sewage sludge and report back to the Council within 90 days.

"The main goal is to implement a new technology that will be less costly, more efficient and not compromise public health and safety," Cachola and Council Chairman Ernie Martin said in a joint statement. Both noted that even had the funds been appropriated, it would have taken at least two years for the digester to come online and that hauling of sludge would still have to occur.

Martin has said the Council will reconsider the funding next year, but he and Cachola noted that they already had approached the administration and proposed a pilot program to allow private companies to test thir technologies at no cost to the city.

"The excess sludge at Sand Island would be used to test their technologies and possibly eliminate the need to truck it elsewhere," the councilmen said, adding that the proposal was agreed to by the administration.

The resolution could still slow the expansion at Sand Island.

"If the City Council puts a condition that we must use one of those (alternative) technologies … then that could slow everything down for some time because then you kind of have to start from square one," Steinberger said, adding that new projects typically take as long as six years to complete.

The interim short-term solution appears to be hauling, but it likely will not begin without a fight.

The City Council has scheduled an informational briefing on the plan for Aug. 3, while community groups on Windward Oahu also are organizing forums to discuss solutions and make presentations on alternative technologies.

Steinberger has said feasibility test runs would be the first step, to determine both the impact on the affected communities and whether the diversion of sludge is effective at managing the over-capacity at Sand Island.

"If we increase the risk at the other facility, then that’s something that we wouldn’t pursue," he said.

The city has experience hauling sludge. Because there are no digesters at treatment plants in Kahuku, Waimanalo, Wahiawa and Paalaa Kai, a total of roughly 216,600 gallons per week is hauled from those facilities to Kailua and Honouliuli. However, only the Wahiawa plant trucks sludge on a daily basis, the others haul on a semi-weekly schedule.

But test runs for the additional hauling from Sand Island are not good enough for some, including state lawmakers from the affected districts who say public hearings and even a formal environmental assessment should take place before the hauling even starts.

State Rep. Cynthia Thielen, a retired environmental attorney who fought the construction of the H-3 freeway, informed the city in a letter that an environmental assessment is needed, based on the 2009 Superferry decision by the state Supreme Court that said such a study is required when there may be secondary impacts on a community.

"I believe that I’m on strong grounds that they need to do an environmental assessment and we’re working on putting together that position paper for the (Aug. 3) meeting," said Thielen (R, Kailua-Kaneohe). She said she had retained the services of a pro bono attorney to help research and craft the position paper, but stopped short of saying she would go to court to force an assessment.

"The difficulty with going to court is it’s a very expensive process," she said. "And obviously, I don’t think that’s the best way to deal with it or the practical way to deal with it.

"I think what has to happen is public outcry to say that this decision is just wrong."

Democratic state Sen. Will Espero, whose district includes Honouliuli, said he would back the effort by Thielen to force an environmental assessment. Rep. Chris Lee (D, Lanikai-Waimanalo) also said an assessment was prudent, though he would defer to the city and City Council to determine the best course of action.

Robert Harris, an attorney and director of the Sierra Club-Hawaii, called the city’s decision "poorly" conceived.

"At first blush, it does appear that there’s a strong potential that they need to do an environmental assessment," Harris said. "That’s clearly something the city should be looking at before they do any transportation of the sewage sludge."

Should the hauling be delayed or stopped, Steinberger said the Sand Island facility could operate for "a few months."

"Obviously, any time you’re pushing at the design capacity you’re now going into that area that we engineers like to call our backup safety," he said. "You don’t like to inch into that area.

"Right now we’re OK and we’ll probably be OK for a few months at the way that we’re going now, but if we continue to see additional solids coming in, then that could be problematic."

That could mean a moratorium and connecting any new projects to the city’s sewer lines, stifling construction in the urban core. Any permits that already have been granted would not be at risk, but it is likely that new permits could be delayed, Steinberger said.

"We’ve only been making these statements publicly so that the public is aware that this is an option that may have to be exercised," he added. "But again, it’s a very last resort."