Lagoons · Common Lagoon Problems
What Is Lagoon Turnover?
Turnover is mixing that happens when changes in temperature and density disturb the lagoon layers. Oxygen-poor bottom water and breakdown products may rise to the top. Operators may see sudden changes in color, odor, DO, pH, or solids.
Turnover is often seasonal, most often in spring and fall. Wind and fast weather changes can also play a part. Overload, toxic influent, aerator failure, or disturbed sludge can cause the same signs. Do not assume turnover without checking the evidence.
Record weather, water temperature, DO at repeatable depths, pH, color, odor, flow, and equipment status. Follow the facility response plan.
Turnover odors usually fade as the lagoon recovers, but they can still draw complaints. Controlled aeration or a change in cell use may help when the design and approved procedures support it.
Key point: Seasonal mixing can bring oxygen-poor lagoon water to the surface and outlet.
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Lagoons and Small Wastewater Plants
This page comes from the course. It covers facultative and aerated lagoons, monitoring, lagoon problems, berms and liners, package plants, permits and safe work, one step at a time, with short knowledge checks and a certificate of completion.
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