by Gregory Field
The Department of Wastewater Management (WWM) is beginning a process of planning for the Wastewater needs of the Waimanalo community. Felix Limtiaco, Department Head of Wastewater Management, outlined the planning process at a public meeting on December 12, at the Waimanalo Library.
"We're going through all Facilities Plans; where we will be going in the next twenty years," said Limtiaco. "It's critical to think about capacity of plant, which is now near its permitted limit."
According to a fact sheet, the Waimanalo Wastewater Treatment Plant facility was designed for an average flow of 1.1 million gallons per day (mgd); however, the rapid block system proved not to be as effective as designed, and the permitted rate of flow is .7 mgd. The city is pursuing evaluating a higher flow by reconfiguring the treatment plant for a short term solution. The Facilities Plan will investigate a long term expansion possibility and associated capital costs.
The WWTP is the only treatment plant run by the city using the rapid block system and WWM would prefer to have a plant similar to others it operates. It is also the only plant owned by the state and operated by the city. Installation of a new system would be a large Capital Improvement Project, but because of the owner/operator arrangement, how the costs would be shared and financed is unknown.
The Facilities Plan
The Facilities Plan will also explore other options to a single treatment plant. Currently, many homes have individual systems--either cesspools or septic tanks--that work perfectly well. Dr. Robert Shleser of the `Aina Institute explained the importance of soil type on the effectiveness of individual systems. Those houses on Jauca sand have an ideal medium to treat their own wastewater on site: one cubic meter of Jauca sand has the surface area required to handle the waste from a family of four. Individual treatment systems can be effective on other soil types as well.
Dr. Shleser showed a map based on the U.S. Geological Survey that defined the extent of Jauca sand in Waimanalo. He suggested the large undeveloped areas in Sherwood Forest and Bellows AFS might prove useful as a place to treat wastewater naturally.
"Conventional treatment plants are for highly urbanized areas," said Felix Limtiaco. "A reuse project is something we're looking at. It is an agriculture area."
Roy Ade, Vice President of Hawaii Pacific Engineers, the consultant firm that will prepare the Facilities Plan, said his firm will conduct 15 soil percolation tests in Waimanalo. "Testing is not to force people onto sewers," Ade said, "but to give us data to make an intelligent decision." All of the testing could be completed in two weeks if access is given by landowners.
In unsewered areas, if a homeowner on cesspool applies for a building permit, the City refers the application to the Department of Health which then requires the owner to upgrade to a septic tank. This could be an added $10,000 to $15,000 expense. The City is not responsible for providing the same level of improvements to rural areas as it does for urban areas. Typically, sewers are available in residential and business areas; it is not feasable or necessary to sewer farm areas with large lot size and a limited population.
The Facilities Plan and associated Environmental Impact Statement will be completed in about a year and a half. According to the schedule, in April 1996 a conceptual plan for a collection system will be presented at a Public Information Meeting (PIM). In August 1996 a conceptual plan for a Treatment Plant will be presented at a PIM. In December 1996 a Pre-Final Facilities Plan will be presented. In March of 1997 a Pre Final EIS will be issued. In July of 1997 the Final EIS will be issued.
The Facilities Plan will also include:
* An Infiltration and Inflow Study. The I/I will report on the amounts and points of infiltration of water to the system during heavy rains.
* A Spill Reduction Action Plan will describe the emergency procedure in the event of an overflow.
* Septic Channeling Facility: The system will be analyzed to see if it could accommodate the septage from pumpers that service septic and cesspools.
Who to call
The Department of Wastewater Management is looking for public participation in the Facilities Plan. A Citizen Advisory Group is chaired by Nancy Glover who can be reached at 259-8946. Tessa Yuen is the Project Manager for the Department of Wastewater Management; she can be reached at 523-4956.