Lanai Non-Potable Alternative Water Source Study

Location: Lanai, Hawaii
Client Name: Castle & Cooke Resorts, LLC
Date Completed: 2005
Construction Cost: $110,000 (fee)
Disciplines Applied: Water & Wastewater Engineering

Project Description:

The Lanai Water Company requested RMTC to prepare a study of additional sources of water on the relatively arid island of Lanai.

After reviewing the existing inventory of water supply, the following alternative sources were examined:

  • Non-potable water with no treatment. This was evaluated as an alternative for the Manele and Koele Project Districts.
  • Non-potable groundwater (treated via desalinization). Feasibility was evaluated for the Manele Project District, including study of alternative grasses at the Challenge at Manele Golf Course.
  • Non-potable surface water via capture of runoff. Both runoff capture alternatives and treatment requirements were evaluated for both the Manele and Koele Project Districts.
  • Non-potable surface water via maximization of wastewater reuse. This evaluation considered the Manele Wastewater Treatment Plan (WWTP) as well as the County of Maui’s Wastewater Treatment Plant on Lanai and the private plant owned by Castle & Cooke Resorts, LLC.

The study found that non-potable water can be developed. Consideration should be given to exploratory well drilling. Desalinization is the most cost-effective alternative water source.