Tetra Tech’s Gordon Monroe, P.E., Carleton’s consulting engineer, collaborated with City Manager Brian Burnham to address the issues. After rejecting traditional aspirating aerators due to maintenance and power concerns, they trialed Titus Wastewater Systems’ Twister FL Floating Aerators. The aerators were chosen for their ability to generate high volumes of dissolved oxygen (DO), reduce algae, and prevent TSS overages with minimal maintenance.

Configured with side intakes, the aerators draw water in sideways, preventing suspension of the lagoon’s seven-inch sludge layer. This allows the aerators to elevate DO levels throughout the lagoon, without disturbing the sludge. Tethered by a single rope with no stainless steel cables, and with an onshore specially designed blower for power, the aerators move large volumes of water, maintaining consistent DO levels (7 mg/L) across the entire lagoon, even 1,000 feet from the units.