WaterTectonics supported lagoon restoration efforts for two wastewater lagoon systems on Moloka’i, addressing long standing water quality challenges that had developed after decades of continuous operation. Over time, the lagoons had accumulated significant volumes of settled sludge and sediment that contributed to ongoing treatment performance issues. Warm temperatures, abundant sunlight, and nutrient rich conditions fueled persistent microalgae blooms. The accumulated sludge and sediments contained elevated phosphorus levels that sustained algal growth, contributing to increased turbidity in addition to elevated total suspended solids (TSS) and biochemical oxygen demand (BOD).
To restore lagoon function and improve water quality, WaterTectonics implemented a targeted sludge removal and circulation strategy. A 300 GPM floating sludge dredge was deployed to remove decades of accumulated sludge and sediment from the lagoons. By removing the phosphorus-rich material, the dredging process reduced a key driver of microalgae growth and improved overall lagoon conditions.
Following dredging, SolarBee® aerator circulators were installed to enhance oxygen transfer and improve lagoon mixing. The circulation system helps reinforce natural ecological stratification within the lagoons while reducing hydraulic short circuiting and improving retention time. Together, dredging and circulation improvements support healthier lagoon ecology and more stable long-term treatment performance.
