Small farms produce wastewater streams that are too clean to need full engineered treatment but too dirty to discharge directly. Milking parlor wash water, produce processing water, and certain food-processing wastes all fit that category. A series of IBC totes configured as a biofilter — settling, anaerobic, aerobic, polish — can treat these streams to discharge or reuse quality at a small fraction of the cost of a packaged treatment system. We have helped half a dozen Missouri and Iowa farms build these over the last few years.
The four-stage layout
Influent enters the first tote, which acts as a settling and equalization basin — water sits long enough for solids to drop and flow to even out. The second tote is anaerobic, packed with floating media that supports a stable population of nitrate-reducing bacteria. The third tote is aerobic, with an air blower at the base supplying oxygen for the bacteria that finish the organic breakdown. The fourth tote is a polish stage with sand or sand-equivalent media for final clarification before discharge or reuse.
Sizing against actual flow
For a small milking parlor producing 200 to 400 gallons per day of wash water, the four-tote system above provides about three days of total residence time across the stages, which is comfortably enough for the bacterial populations to do their work. For larger flows, scale the totes up in parallel rather than series — adding a second settling tote in parallel with the first, for example — to preserve residence time without making the footprint unwieldy.
- Settling tote with 24 to 48 hour residence
- Anaerobic biofilter with floating media
- Aerobic biofilter with aeration
- Polish stage with sand or similar media
- Discharge or reuse pump on a level switch
Regulatory framing
Discharge from on-farm wastewater systems is regulated at the state level. Missouri DNR has specific guidance for small dairy and produce operations that distinguishes between confined animal feeding operations and smaller farms. Most farms running tote-scale flows fall under general permits or below permitting thresholds entirely, but the only way to know for sure is to check with the state office before designing the system. We have referenced contacts at the relevant state offices for customers who want to start that conversation.
Cost comparison
A packaged engineered wastewater system sized for 400 GPD typically runs $18,000 to $35,000 installed. A four-tote biofilter system, including the totes, media, plumbing, and a small blower, runs about $1,800 to $3,200 in materials, assuming the farmer does the assembly. The performance is not identical — engineered systems produce more consistent effluent quality across upset conditions — but for steady-state flows on a small farm, the tote system meets discharge standards reliably.