Recycled Water Program

Recycled water is derived from wastewater that has been treated to various quality grades (via oxidation, disinfection, and/or filtration) depending on its intended use. Use of recycled water has become more significant due to the state’s growing population, limited potable water resources, and wastewater disposal issues.

The Reuse Guidelines were revised in January 2016 and separated into two volumes. Volume 1: Recycled Water Facilities addresses technical requirements to be met for various qualities of recycled water, and requirements to construct or modify a wastewater reclamation facility. Volume II: Recycled Water Projects covers the application process to use recycled water for various purposes and establishes best management practices that apply to the end user.

RECYCLED WATER (RW) USE (MILLION GALLONS PER DAY)

County 2015 2016 2017 2018 2019 *2020
Oahu 10.4 11.1 12.1 12.1 11.8 12.3
Maui 3.6 4.0 3.9 3.1 3.3 3.9
Kauai 2.4 2.1 2.1 2.7 1.8 2.1
Hawaii 1.6 1.7 1.5 1.3 1.2 0.7
State Total 18.1 18.9 19.5 19.2 18.2 19.0

*The Covid-19 pandemic and subsequent tourism decline decreased the RW volume produced by plants servicing resorts.  However, for municipal plants servicing existing residents and businesses, the RW volume suppled was generally stable or slightly increased due to dry weather demand.

Volume 1:  Recycled Water Facilities | .pdf |

  • Recycled Water Application Form:  Construction Extension | .pdf |
  • Report Form:  Annual Report on Recycled Water Supplied for Use | .pdf |
  • Report Form:  Recycled Water Spills | .pdf |

Volume 2:  Recycled Water Projects | .pdf |

  • Recycled Water Use Maps: Link to GIS website
  • Recycled Water Project Notes | .pdf |
  • Recycled Water Application Forms:
    • General Irrigation |.pdf |
    • Agricultural Irrigation | .pdf |
    • Non-Irrigation Use | .pdf |
    • Temporary R-1 Use | .pdf |
    • Construction Extension | .pdf |

GRAY WATER

Gray water is defined as wastewater discharged from sources such as showers, bathtubs, hand-washing lavatories, and clothes-washing machines. Residential use of gray water is allowed per the following guidelines:

  • Guidelines for the Reuse of Gray Water | .pdf|