The city cannot begin trucking of raw sewage into Kailua, or other communities, until an environmental assessment is completed to examine secondary impacts, a state lawmaker contends.

In a letter to the city, Rep. Cynthia Thielen (R, Kailua-Kaneohe) cites a 2009 ruling by the Hawaii Supreme Court stating that an assessment is required by law when there could be secondary impacts.

Thielen’s letter was in response to the city’s announced plans to begin trucking raw sewage sludge to waste-water treatment plants in Kailua, Honouliuli and Waianae to help relieve the over-capacity Sand Island Wastewater Treatment Plant in Honolulu.

Hauling would be temporary as the city administration and City Council work out an expansion of the Sand Island facility.

The city had begun design and planning for a second “digester” at Sand Island and requested $26 million for it, but the money was taken out of the budget by Councilman Romy Cachola over concerns about the plant’s operator, Synagro Hawaii, and reported health concerns surrounding the fertilizer pellets being produced by the “in-vessel bioconversion” process.

Hauling was expected to commence by the end of the month, after initial test runs at the waste-water plants.

City Environmental Services Director Tim Steinberger had not yet seen the letter Monday and declined to comment on its specifics.

“The city and the Department of Environmental Services has and will continue to follow all environmental laws,” he said through a spokesman.

Trucking the sewage sludge to the Kailua Wastewater Treatment Plant, Thielen wrote, could have secondary impacts including but not limited to odor and noise for residents, increased traffic on residential roads and additional burden on the treatment facility.

She cited a 2009 Hawaii Supreme Court ruling stating that an environmental assessment is needed when such impacts might occur.

“Please know that I will pursue all available means to ensure that the Department of Environmental Services does not commence trucking raw sewage sludge to the Kailua plant until it fulfills its comprehensive legal requirements under (the law),” Thielen wrote in her letter, dated Monday.

Democratic lawmakers from Kailua held a news conference Saturday to express similar concerns over the planned sludge hauling.

The city says hauling is a temporary solution as work is completed at Sand Island on the second digester, which is expected to come online by late 2013. The city plans to ask for the $26 million again next year.

The Council has passed a resolution asking the city to examine alternative technologies for reusing sewage sludge and report back on its findings by early October.