Overview
- The permanent $1.7 million ozone “nanobubbler” was delivered and installed out of sight in a nearby pump house and was reported ready to operate by June 25.
- Temporary nanobubbler units were first placed in the pool on June 6, removed at the National Park Service’s request on June 12, and workers reported generator failures that coincided with the first visible algae blooms.
- The nanobubbler technology blasts microscopic oxygen bubbles into water to break up algae and bacteria but has been used only on waterways before and not previously tested in a pool setting.
- The Department of the Interior defended the largely no-bid contracts used for the fast-tracked $14–16 million renovation, while six people were arrested in alleged vandalism cases and President Trump blamed deliberate sabotage.
- Independent testing and internal reports flagged coating bubbles, pinholes and nutrient-rich feedwater, and experts say algae is likely to recur until the century-old 12-inch buried circulation pipes and other structural issues are repaired, with preservation lawsuits and oversight inquiries ongoing.