# Honolulu begins $417M secondary treatment upgrade at Sand Island wastewater plant

Phase 1 of the Sand Island Wastewater Treatment Plant secondary treatment installation is underway, a $417 million project treating 20 million gallons per day, with completion on track for 2026.

- Type: Expansion
- Announced: 2024-06-11
- Where: Sand Island, Hawaii, United States
- Value: $417.0M
- Starts operating: 2026
- Status: under construction
- Capacity: 20 million gallons per day
- Products: wastewater treatment
- Sectors: [Water Treatment Equipment](https://endata.com/sectors/water-treatment-equipment.md)

## Companies

- [City and County of Honolulu](https://endata.com/companies/69528.md)
- [AECOM](https://endata.com/companies/3034.md) (partner)
- [Hensel Phelps](https://endata.com/companies/75295.md) (partner)

## Sources

- [enr.com](https://www.enr.com/articles/58801-advanced-water-treatment-finds-resilient-footing), 2024-06-11: "Construction has reached the halfway point on Phase 1 of the Sand Island secondary treatment installation: a $417-million, five-year project that will treat 20 million gallons per day of SIWWTP's total 90-mgd capacity."

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Data from Endata (https://endata.com/). Announcements are summarized from public sources and may be incomplete; check the linked originals.