We speak for the land, the groundwater and concerned residents and members of Aikahi Gardens, Healani Gardens, Kalaheo Hillside and the Kalaheo High School Parent-Community Network.

This past year, in response to a proposal for construction of a large gravity sewer tunnel inside Oneawa Hills, we have met with the city and submitted a position paper and a 50-question inquiry.

Recent letters by resident Rudy Yap ("Aikahi sewage plant beyond its capacity," Star-Advertiser, Letters, May 15) and city employee Wesley Yokoyama ("Sewage tunnel design carefully thought out," Letters, May 20) have prompted us to publicly voice our concerns.

Beginning phases of the required environmental impact statement preparation had planners, Wilson Okamoto Corp., inviting handpicked participants to a core working group. The planners’ website described meetings "with stakeholders whose interest and activities are potentially affected by the proposed project" and are "along the alignment."

Three of the four aforementioned groups were left off that invitation list, despite the fact all the residents live on or next to the hill or at the entrance and exit of the tunnel. Aikahi Gardens had a representative at one meeting who never shared information gathered with owners.

We are sitting on or beside the eroded edge of the volcano that formed Windward Oahu. Developers cut terraces into the basalt, especially on the Mokapu Boulevard side, molded areas with dredged adobe clay, and built homes on top. Nearby areas were filled with various material. Both applications have presented grave problems. The clay adheres to rock only when really wet, cracking widely and slipping when dry, taking structures above along for the ride. Poorly tamped fill areas result in misaligned buildings. Add to that the fact that volcanic rock is a honeycomb of now empty lava tubes that can crack, creating large sink holes, and you have a recipe for disaster. The exact location of the tubes is unknown.

An EIS is a disclosure of potential negative environmental impacts and mitigation plans to lessen those impacts.

This EIS is lacking in mitigation, just statements that the worst scenarios are not going to happen. It is worrisome that Hawaii is one of only a few states that allows the same office to be both the proposing agency of a project and the accepting authority — in this case, the city’s Environmental Services Department. This lack of oversight must be legislatively remedied.

Referring to either the 1955 Soil Survey of the area or a 1992 appraisal report, the city would have been aware of "unstable clay covered rocks," "soil that slumps after wetting and drying" and "soil that creeps downslope when disturbed." The appraiser added "that condition had been commonly known for many years."

Some members of the core working group questioned why the project could not go down Mokapu Boulevard, which despite being a force main rather than a gravity main is a similar alignment, does not threaten property damage or irreversible groundwater contamination nor require the huge lift pump facility in the present plan.

We are ill at ease with the EIS statements "Hawaii’s summer is the wet season," "cost estimates done with little boring information" and "in some places the boring machine may not be feasible, so drill and blast may be required." The fact of both ground and air vibration during construction and permanent gushing of millions of gallons of raw sewage inside the hill entering a substandard sewer plant are significant concerns.

This is not a "not in my backyard" issue. We must increase the carrying capacity of our antiquated sewer system to prevent spills, but it must be dealt with in a way that neither poisons the natural environment nor subjects citizens to unnecessary hazards.