A sewage lagoon may look like it’s operating the same as it always has while water is secretly leaking out of a low quality, cracked liner. Water conditions can change from day to day as temperatures fluctuate. Watch out these common signs that something has gone wrong with your sewage treatment pond. A quick response minimizes the effort required to return the lagoon to its usual balance of bacteria or water holding capacity.
Some algae is natural, and desired in a pond, since these tiny water plants help break down excess nutrients. However, a sudden bloom in algae means that mixture of sewage has changed. If you’re relying on a specific ratio of waste to water to ensure safe decomposition within a certain time frame, you’ll want to track these changes and make adjustments. Algae blooms also reduce water oxygenation, which is a serious problem in a naturally or artificially aerated system. Without enough oxygen, the bacterial balance changes from aerobic and anaerobic. Vegetation overgrowth in the water or on the banks also indicates an imbalance that is high in nitrogen, producing unhealthy conditions that interfere with proper water treatment.
A minor smell of sewage is expected from any lagoon, no matter how well it operates. Aerated lagoons receiving raw materials may have a stronger odor. However, the smell should be well-contained and only noticeable at the banks of the pond. If the odor is changing or spreading further than before, the system is becoming overloaded and is no longer processing the water as designed. This can also occur during the cleaning and sludge removal stages, especially in anaerobic ponds. Unless you’re cleaning or pumping a pond, you should investigate any odor changes or increased unpleasantness.
Bubbling is a natural part of waste decomposition in a lagoon, especially in the deeper anaerobic pond. If you notice a sudden stop to all bubbling or a serious increase, you may be experiencing unwanted bacterial growth or a die-off event. Bacterial die-off halts the natural treatment process and may require the use of additional chemicals or additives to balance out the problem. Increased bubbling indicates the creation of gas like methane. The pond may need stirring or raking to break up pockets of gas-producing bacteria before they can multiply.
Wet soil around the lagoon, even if it’s dozens of feet away from the pond’s edge, is a clear sign that the liner is leaking. Unlined lagoons commonly transform the soil around them into soft and soggy mud. Unlike the ground around leaking ponds that contain only fresh water, this soil is contaminated with bacteria and viruses that can spread to humans walking around on its surface. Start a leak-finding procedure any time you notice unusual dampness or softness of the soil around a lagoon, especially on the banks.
The only healthy colors for sewage lagoons, especially active treatment ponds, are translucent light blue and light green. These all indicate that bacterial colonies are keeping up with demand and any physical treatment methods like filters and settling are achieving their goals. Light brown water is common in bulk holding ponds, but larger treatment lagoons shouldn’t stay this color unless there’s disturbance from sludge removal or heavy rainfall. Thick green or blue water is high in cyanobacteria and is not progressing through treatment properly. Completely clear water is often too high in ammonia unless it’s in a polishing pond for discharge. Black and solid gray water is septic and failing to decompose, meaning it’s basically in stasis until conditions improve.
Any of these warning signs can be easily overlooked until a sewage lagoon starts to cause more serious problems. Use your eyes and nose to give your lagoon an informal check once a week or so and you’ll spot early warning signs of trouble while the problems are still easy to fix.