---
title: "Wastewater: problems we treat | Alchemal"
url: "https://alchemal.com/wastewater/problems/"
description: "The problems we treat in treatment lagoons and reactors, what is actually happening in the water, and what usually fixes it."
source: "Alchemal — alchemal.com"
---
# What goes wrong in treatment lagoons and reactors

Each page explains what is actually happening in the water, what usually fixes it, and when oxygenation is not the right tool.

9 problems

## What are you seeing?

- [Filamentous bulking: sludge that will not settle When the basin runs short of oxygen, filament-forming bacteria can take over and keep the sludge from settling. See where holding oxygen shifts the balance back, and where it does not.](https://alchemal.com/problems/filamentous-bulking-poor-settling/)

## What are you smelling?

- [Lagoon odor and sludge: keep the column aerobic Odor complaints, crusting, and sludge that makes pumping harder. One anaerobic cause sits behind all three.](https://alchemal.com/problems/lagoon-odor-sludge/)
- [Headworks and basin odor: hydrogen sulfide off a plant that ran short of oxygen A plant's rotten-egg odor is usually hydrogen sulfide from anaerobic water in the collection system or a basin. See how holding oxygen shifts the biology off that path.](https://alchemal.com/problems/headworks-basin-odor/)

## What are you losing?

- [When aeration cannot keep up: low dissolved oxygen under load When the load climbs and the blowers cannot hold dissolved oxygen at setpoint, the culture slows and treatment falls behind. See how oxygen transfer changes the math.](https://alchemal.com/problems/aeration-cant-keep-up-load/)
- [Incomplete nitrification: ammonia riding through on the permit Nitrification is the oxygen-hungry step, and its slow-growing bacteria stall first when DO sags, so ammonia rides through. See how steady oxygen keeps the conversion complete.](https://alchemal.com/problems/incomplete-nitrification-ammonia/)
- [Wet weather and shock loads: when the demand arrives all at once A storm surge or a sudden slug of load can crash dissolved oxygen faster than the blowers recover. See how held oxygen gives the basin more headroom through a peak.](https://alchemal.com/problems/wet-weather-shock-loads/)
- [Tightening nitrogen and phosphorus limits: where oxygen helps, and where it does not Nutrient limits keep tightening. Oxygen completes the nitrification half of nitrogen removal; denitrification and phosphorus are separate steps. See where oxygen fits, and where it does not.](https://alchemal.com/problems/tightening-nitrogen-phosphorus-limits/)
- [Treatment lagoon short-circuiting: flow that skips the pond and dead zones that sour A treatment lagoon short-circuits when flow finds a fast path and stagnant corners sour. See how oxygen through the column narrows the dead zones, and where hydraulics are the real fix.](https://alchemal.com/problems/treatment-lagoon-short-circuiting/)

## Tired of treating it?

- [The energy cost of aeration: paying for oxygen that never dissolves Aeration is usually the largest power draw at a plant, and coarse bubbles lose much of it at the surface. See how transfer efficiency, not blower size, sets the bill.](https://alchemal.com/problems/aeration-energy-cost/)

## Tell us what your water is doing.

A specialist reads your description and replies in writing: what it usually means and what we would measure first.

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