Should I buy a used porta potty for my farm instead of renting one long-term?

Marcus covered the waste disposal costs, but he left out winterization. A standard unit freezes solid in Montana winters without antifreeze in the holding tank. You need to add a brine solution or non-toxic antifreeze regularly, and the door latch and seat can crack in the cold. For 10 hands, one standard portable toilet meets OSHA, but you must handle all that yourself if you buy. The rental company's service visit includes winter prep, which is one less thing for you to manage.

Buying a used portable toilet can be cheaper than renting if you have the means to handle waste disposal and cleaning yourself, but the ongoing logistics are significant. A standard unit is a simple tank, but you become the operator. The real cost is in the waste disposal. You must hire a licensed septic hauler with a vacuum truck to pump the holding tank. They charge for the trip and the disposal fee at a wastewater treatment plant. Illegally dumping waste carries heavy fines. For 10 workers, OSHA 1926.51 requires one toilet, so one unit is sufficient. You also need to buy deodorizer, which is a chemical mix with dye and biocide, and replenish toilet paper. Most operators use a formaldehyde-free deodorizer because treatment plants restrict formaldehyde. Cleaning between uses means hosing out the interior. The used unit itself may need repairs to the door latch, vent stack, or tank. For a fixed location with easy truck access, buying could save money over several years, but you take on the hassle of scheduling service and maintaining the unit.

Buying a used unit works if you can handle the waste disposal, but Luis is right about winter. The bigger thing they both missed is the legal side for a farm. You aren't a construction site, so OSHA 1926.51 might not be your only rule. Some county health departments have their own rules for agricultural worker sanitation, including how often you must pump the tank. You'd be responsible for knowing and following those. Also, a used unit might have a cracked tank you can't see. A rental company's monthly rate includes the unit, all service, and they carry the liability if something fails. Your cost to own is the unit price plus every pump-out, plus your time managing it all.