KAHALU'U — A proposed 44-home subdivision in 'Ahuimanu is raising concerns in the quiet neighborhood where residents worry about too much development, more septic tanks and overburdened roads.

Residents say the project's size is not in keeping with the surrounding area of one-acre lots and the effect of the added septic tanks and traffic could put a strain on the community.

One of their major concerns is that adding so many septic tanks in an area with such heavy rainfall could make wastewater overflow and run off to nearby properties, then into area streams.

Aiello Development Group LLC, which is building the project — named The Woods at Ahuimanu — said it will work with the community to address those concerns.

Aiello Development Group wants to subdivide 15.4 acres near the upper levels of 'Ahuimanu Road into 47 lots of 10,000 to 35,000 square feet. It plans to build 44 homes that would be between 2,000 to 2,800 square feet. Two of the lots at the top of a hillside would remain vacant and a third lot would be used as a catch basin for rainwater.

The project is set in a rural community that values its country lifestyle and says it doesn't want big development.

The people say that they like having their roads free of heavy traffic and street lights, which obscure the stars. And with 80 to 120 inches of rainfall a year, they worry about the environmental effects a new subdivision might have on the area.

Some residents felt that the landowner had a right to develop his land, but they asked that the company consider making the lots into one-acre parcels. Peter Aiello, the project's manager, said that larger lots would increase the home prices by 300 percent.

The homes are not yet for sale.

Once all permits are obtained, construction would begin with a target completion date of May 2007. In today's market, he said, the homes would cost $800,000 to $950,000.

Michelle Lesperance, who lives 10 blocks below the proposed subdivision, wondered how the project and the increased traffic would affect her lifestyle and if the developer would somehow compensate the neighborhood.

"Are my animals going to be hit?" she asked. "Can my son still ride his bike with all the speeders going back and forth?"

Residents figured that 44 units could mean 88 more cars and more than 100 new residents traveling on 'Ahuimanu Road, which has no sidewalks or curbs. They said they feared that would lengthen their daily commute.

At a recent Kahalu'u Neighborhood Board meeting residents asked about an Environmental Impact Statement for the project. But an EIS isn't needed because the developer isn't asking for a zone change, Peter Aiello said.

The zoning for the 15.4 acres is R-10 and R-5, which would have allowed the owner to subdivide into 108 lots, Aiello said. However the developer wants to maintain the rural atmosphere in the subdivision and since the area has no municipal wastewater hookup, lots had to be at least 10,000 square feet to accommodate a leach field for septic tanks as required by the state Department of Health, he said. The average lot size in the subdivision is 15,000 square feet.

To minimize runoff, plans call for channeling water to a sediment collection basin that would release filtered water into Kahalu'u Stream, Aiello said. In addition, the developer will increase the size of the culvert under an 'Ahuimanu Road bridge near the subdivision at a cost of $750,000, he said.

"I'm trying to take care of the environment," he said. "The environmental rules are mind-boggling, and we're following them to the letter and some."

But residents questioned the capacity of a 10,000 square-foot lot to hold the contents from the septic system during heavy rains and when the ground is saturated. Some predicted the wastewater would drain to lower properties. Others fear the basin might spill over during a downpour.

"I've lived there for 20 years," said Glenn Martin. "When it rains the pond is not going to hold anything; it's going to overflow."

" 'Ahuimanu Road becomes a streambed in heavy rain," said Allan Samuelson, who lives on an acre lot next to the subdivisions. "It goes under the bridge and tore off the pavement twice."

Another retention pond in a lower section of 'Ahuimanu Stream isn't working well, said Sandra Lee, who lives near the pond. It is infested with mosquitoes, Lee said adding that cesspools are also problematic, and some overflow in heavy rains.

Steep grades and heavy rains can cause problems with cesspools and leach fields said Harold Yee, program manager for the state Department of Health Wastewater Branch. Wastewater Branch works with property owners to ensure wastewater systems work — and his office has had many complaints in the 'Ahuimanu area, Yee said.

"If you're too close to your neighbor or if you have enough of a slope, sometimes it will seep out, leak out, especially if people start putting walls in between properties," he said. "It happens all over the state. That's something the designer, the engineer has to look out for."

Yee said the 10,000 square-foot lot is a minimum size for a leach field but the state has other considerations in designing leach fields such as how water percolates through the soil and the slope of the land.

The subdivision is flat at the bottom, mildly sloped in the midsection and steeper at the top, Aiello said.

The U.S. Environmental Protection Agency no longer allows for large cesspools in the state. The city also hopes to hook up all O'ahu homes, including those in 'Ahuimanu, to its municipal system some day. In anticipation of that, Aiello said his homes will have the necessary hookups for the city sewage collection system.

The project, which has tentative subdivision approval, has many of the necessary permits and is waiting for its Water Quality Permit and final subdivision permit. Once approved it must obtain building permits.

Wayne Panaoke, a Kahalu'u Board member, was upset that the Aiello group had progressed this far in its planning before coming before the board to discuss its project.

He said zoning laws should be changed to require that homes be built on larger lots.

Reach Eloise Aguiar at eaguiar@honoluluadvertiser.com.