Tropical Storm Lala knocked out power across parts of Oahu on 17 August 2026, triggering at least four sewage spills and leaving the Hawaii Department of Health unable to test coastal water quality because its Clean Water Branch office and state laboratories were still without electricity on the Tuesday evening after the storm, according to reporting published 19 August 2026 by the Honolulu Star-Advertiser.
Key takeaways
- At least four sewage spills were reported on Oahu during Tropical Storm Lala, including two at the Ala Moana Wastewater Pump Station blamed on backup-power failure (Honolulu Star-Advertiser).
- Sand Island Wastewater Treatment Plant discharged sewage into state waters from around 8:20 a.m. Sunday until the evening, with the cause still under investigation and the volume unknown (Honolulu Star-Advertiser).
- Hawaii American Water released about 717,000 gallons of partially treated wastewater through its Sandy Beach outfall after a power outage, restoring service with a generator in under three hours (Honolulu Star-Advertiser).
- The Department of Health said its Clean Water Branch office and laboratories remained without power on Tuesday evening, blocking coastal water testing (Honolulu Star-Advertiser).
What happened: storm-driven power loss cascades into spills
Reporting published 19 August 2026 says power outages triggered by Tropical Storm Lala caused at least four sewage spills on Oahu, with the Ala Moana Wastewater Pump Station accounting for two of them after backup power failed (Honolulu Star-Advertiser). At Sand Island Wastewater Treatment Plant, sewage began entering state waters around 8:20 a.m. on the Sunday of the storm and was not contained until that evening, City and County of Honolulu Department of Environmental Services spokesperson Jenn Boneza told the paper, adding that the cause is still under investigation and the spill volume is not yet known (Honolulu Star-Advertiser). "She added that it takes a few days for water testing results to return and that the agency should have more information next week," the Honolulu Star-Advertiser reported.
Separately, Hawaii American Water, which treats wastewater for 30,000 residents on Oahu, reported that around 717,000 gallons of partially treated wastewater discharged through the company's outfall at Sandy Beach following a Sunday power outage, lasting just under three hours before the company restored power with a generator; the utility posted signs and urged the public to avoid contact with the water until further notice (Honolulu Star-Advertiser).
What happened: post-storm water testing is on hold
The Hawaii Department of Health told the paper its Clean Water Branch office and state laboratories — the sites that run the bacterial samples — were still without power on the Tuesday evening after the storm, so coastal water testing has not yet resumed, according to the Honolulu Star-Advertiser. The agency said storm runoff can elevate pollutant levels regardless of testing, that gastrointestinal illness is the main public-health risk, and that the areas where spills occurred are covered under statewide brown-water advisories, which typically run 48 to 72 hours after rainfall stops and the beach has had full sunshine (Honolulu Star-Advertiser). When sampling does resume, the agency is required to issue public notifications if elevated fecal bacteria are detected (Honolulu Star-Advertiser).
Specification read: what this means for a plant
Putting the reported numbers in buyer units: the 717,000-gallon Sandy Beach discharge over just under three hours is roughly 239,000 gallons per hour, or about 2,170 m³/day on average across the event window (arithmetic from the 717,000-gallon figure reported by the Honolulu Star-Advertiser). The plant serves a stated 30,000-resident base, so the event is roughly 72 litres per resident per day in spilled volume — well below typical dry-weather flow but still a partially treated discharge into coastal waters. A coastal municipal site of this class runs screening, grit removal, primary clarification, biological treatment (commonly an activated-sludge or MBBR train, with MBR where space or effluent quality demands it), and tertiary filtration plus disinfection before ocean discharge. The Lala event bears on the front of the train: lift stations and pump stations (Ala Moana) and the head-of-works power and backup-power architecture (Sand Island, Hawaii American Water) — the stages that fail first when grid power drops, before any biological stage is even loaded. Brown-water advisories after tropical-storm rainfall are a recurring operating condition in Hawaii, and statewide coastal flood zones overlap with high-priority cesspool zones flagged by the University of Hawaii Sea Grant, which compounds post-storm bacterial loads regardless of plant performance (Honolulu Star-Advertiser).
Recognition sentence: if your facility is a coastal municipal or utility wastewater plant in the 2,000–10,000 m³/day range, with a sea outfall and a wet-weather consent that already runs close to permit limits, this event is a reminder that lift-station backup power, head-of-works generator sizing and on-site lab power are the spec lines that decide whether a storm stays a wet-weather event or becomes a spill report. Specifiers weighing an upgrade path typically compare Integrated Sewage Treatment packages with the resilience of the upstream collection system covered in the Municipal sector hub, and a related comparable program is the Surrey Connect North Shore Wastewater Plant cost at $5.5B, September 2026. For plants that also handle pulp-and-paper-strength loads, the trade-offs between DAF and primary clarifiers are laid out in the DAF vs Clarifier for Pulp & Paper Wastewater in Fernandina Beach: 2026 Factory Guide and the Paper sector hub.
FAQ
What triggered the Oahu sewage spills during Tropical Storm Lala? Loss of grid power and the failure of backup power at the Ala Moana Wastewater Pump Station, with a separate, still-under-investigation discharge at Sand Island Wastewater Treatment Plant (Honolulu Star-Advertiser).
How large was the Hawaii American Water discharge at Sandy Beach? About 717,000 gallons of partially treated wastewater, released over just under three hours after a Sunday power outage, before the company restored power with a generator (Honolulu Star-Advertiser).
Why is coastal water testing still on hold? The Department of Health said its Clean Water Branch office and state laboratories were still without power on the Tuesday evening after the storm, so it could not run fecal-bacteria samples (Honolulu Star-Advertiser).
What backup-power and lab-resilience upgrades are typical for a coastal plant in this class? General industry range, not from the sources: lift-station backup generators sized for the full connected load with automatic transfer switches, on-site diesel or natural-gas standby at the head of works, and either on-site lab UPS capacity or a service contract that brings mobile lab power online within 24–72 hours. Procurement leads should expect generator lead times of several months for utility-rated units and should plan compliance-critical lab power into the next budget cycle, alongside any Integrated Sewage Treatment upgrade.
