You need at least 16 to 20 portable toilets total for 800 people at a five-hour marathon, with more units at the finish line than the start. A good split is 6 to 8 units at the start and 10 to 12 at the finish, because runners tend to use the facilities more after the race. The event planning guideline is about one portable toilet per 50 to 75 people for a four-hour event, and you add units for longer duration. Since your event is five hours and includes snacks, plan toward the higher end of that range.
For unit types, use mostly standard units. Include a few deluxe units with sinks for freshening up; a ratio of one deluxe for every four or five standard units is common. You must also provide ADA-compliant units to follow the ADA 5 percent cluster rule. Since you have two clusters (start and finish), you need at least one ADA unit at each location. Place it on level ground with a clear path for wheelchair access.
For event staff, OSHA 1926.51 requires one toilet per 20 workers. Add separate units for volunteers and crew if they number over 20. Service frequency is weekly for normal use, but for a one-day event like this, you schedule a single service after the event. The rental cost is driven by the number of units, the types (deluxe and ADA units cost more than standard), the rental duration, and the delivery distance. Add-ons like handwash stations or extra servicing also increase the price.
