Dirty Lagoon? 5 Signs Your Wastewater Lagoon Needs Sludge Removal NOW

Wastewater lagoons are designed to be simple, reliable, and low-maintenance — but they aren’t maintenance-free. Over time, solids settle to the bottom, forming thick layers of sludge that slowly start to choke treatment performance. A lagoon that once operated smoothly can turn into a problem system with odors, reduced capacity, and compliance concerns.

If your lagoon is looking a bit dirtier than it used to, it may be telling you something. Here are the five biggest warning signs that your wastewater lagoon needs sludge removal right away.

1. Your Lagoon Depth Is Shrinking

One of the earliest indicators of sludge buildup is lost depth. As solids settle, your lagoon becomes shallower and loses hydraulic capacity. Less depth means less oxygen transfer, weaker biological activity, and slower treatment. If you’re no longer hitting the design depth — or if your sludge blanket is rising — it’s time for a cleaning.

2. Odors Are Becoming a Regular Problem

Healthy lagoons smell like… well, not much. But when sludge accumulates, anaerobic zones form at the bottom, producing strong odors, including sulfur-type smells. Persistent lagoon odor is one of the clearest signs that sludge is fermenting underneath the surface and needs to be removed.

3. Treatment Performance Is Dropping

If BOD, TSS, ammonia, or effluent clarity are suddenly slipping, sludge buildup may be the cause. Thick sludge layers reduce water circulation, disrupt settling zones, and force solids back into the treatment path. A lagoon that’s not removing nutrients effectively often needs sludge removal as the first step.

4. You’re Seeing Increased Algae or Surface Scum

Algae blooms thrive in lagoons with high nutrient levels — especially nitrogen and phosphorus released from decomposing sludge. If your lagoon looks green, foamy, or has floating mats of algae or scum, your sludge layer is likely feeding it from below. Removing sludge helps restore balance and prevent excessive blooms.

5. The Lagoon Is Reaching or Exceeding Capacity

As sludge fills the lagoon floor, the available treatment volume decreases. Eventually, the lagoon begins to behave like it’s “too small,” even though the footprint hasn’t changed. If your lagoon is taking longer to process flow, backing up during storms, or no longer handling peak demand, sludge removal can restore valuable capacity and save you from costly expansions.

How Sludge Removal Restores Lagoon Performance

Removing sludge from a lagoon instantly improves depth, oxygen transfer, circulation, and biological performance. Modern dredging and pumping systems allow sludge to be removed without draining the lagoon or shutting down operations, making the process faster and more cost-effective than ever. Pairing dredging with mobile dewatering drastically reduces disposal costs and helps facilities get back to full operating efficiency.

Need Lagoon Sludge Removal? Magna-Flow Can Help.

Magna-Flow provides professional lagoon cleaning, sludge removal, dredging, and on-site dewatering for wastewater treatment plants, municipalities, and industrial facilities across Texas.

If your lagoon is showing any of these warning signs, we can perform a sludge assessment and recommend the right solution.

Fill out our form today for a free quote or evaluation.