Published September 9, 2026
The system
The feedlot near Sterling, Colorado collects waste from its cattle pens in several large lagoons. One lagoon that had filled with solids was selected for the study. It is about a quarter mile long with an average width of 150 feet, about 198,000 square feet of surface, ten feet deep, and holds about 45.5 acre-feet. Pen waste is hauled to the lagoon by front-end loader through three alleys, and hauling continued every day of the study. The study document is titled October 2017.
The problem
Solids had been building steadily as new waste was added daily. When the lagoon was completely full it would need costly dredging: the trucking, the landfill or land application, and the lagoon out of service while the crew worked. The goal of the study was to reduce the quantity of solids in the lagoon while it stayed in use, by giving the bacteria already living in it what they needed to break the solids down faster.
What we did
The accelerator was applied to the lagoon surface once a week for five weeks. The first application was 110 gallons of accelerator diluted in 400 gallons of fresh water, sprayed evenly over the surface. Each of the following weeks, 55 gallons was diluted in 200 gallons of fresh water and sprayed the same way. The completed treatment used 275 gallons of accelerator, which the study describes as the equivalent of about 300 pounds of product. No bacteria, enzymes or chemical additives were added, and nothing about the feedlot’s routine changed: waste kept arriving daily.
How it was measured
Before the first application a boat was taken onto the lagoon and fourteen sample points were chosen across it. Each point was marked with a cork on a weighted string long enough to reach the bottom, so the same spot could be found again. At each point a measuring stick with a flat plate on the end was lowered slowly until it rested on top of the solids, and the depth of water above the solids was recorded. The overall lagoon level was measured at the same time so the readings could be corrected. After five weeks the fourteen points were measured again the same way. Rain during the five weeks had raised the lagoon by four inches, so four inches were deducted from the second set of readings. The table shows the readings as printed in the study.
| Point | Depth of water before treatment (inches to solids) | Depth of water after five weeks (inches to solids) | Decrease in depth of solids (inches) |
|---|---|---|---|
| 1 | 12 | 20 | 8 |
| 2 | 12 | 20 | 8 |
| 3 | 12 | 20 | 8 |
| 4 | 12 | 25 | 13 |
| 5 | 10 | 23 | 13 |
| 6 | 12 | 24 | 12 |
| 7 | 10 | 20 | 9 |
| 8 | 12 | 27 | 15 |
| 9 | 10 | 25 | 15 |
| 10 | 11.5 | 22 | 10.5 |
| 11 | 11 | 27 | 16 |
| 12 | 11.5 | 18 | 6.5 |
| 13 | 15 | 22 | 7 |
| 14 | 22.5 | 22.5 | 0 |
Results
The depth of solids fell at thirteen of the fourteen points, by between 6.5 and 16 inches, and was unchanged at the deepest-water point. Across the lagoon the study calculates over 150,000 cubic feet of solids removed, which it equates to forty-six tractor-trailer loads of sludge and a ten percent reduction in the solids in the lagoon, accomplished while the lagoon was still receiving waste every day. The study notes that gas bubbles covered the lagoon surface during treatment and had not been there before, which it reads as a sign of the increased bacterial activity. Its recommendation was to treat all the feedlot’s lagoons continuously so that each reaches a balance point where solids are broken down as fast as they arrive.
Limitations
This is one lagoon over five weeks with no untreated lagoon for comparison. The rainfall correction is a single four-inch adjustment applied to every point, and the study does not say whether the printed after readings already include it. A plate on a stick finds the top of the solids by feel, so readings at the same point can differ by an inch or two between operators. The cubic-feet and truckload totals are the study’s own calculation from the fourteen points and the lagoon’s dimensions, and the daily waste added during the study was not weighed. Gas bubbles show activity, not which bacteria are active. A feedlot with a different lagoon, loading or climate should expect a different result, which is why we measure each lagoon against its own baseline.
Proof assets
- The study document, with the sample-point diagram, the application record and the fourteen-point table.
- The before and after readings above, as printed in the study.
- Waste Water Innovations is confirming the feedlot’s written permission to publish its name.