Weekly vs twice-weekly service on a summer job site: when does the second service pay for itself?

A second weekly service pays for itself when crew complaints and lost productivity cost more than the service. With 45 workers in Phoenix heat, two standard-units and one ada-unit are at the OSHA minimum for 36 to 55 employees, but heat and full usage push them past capacity by Thursday. Heat accelerates bacterial growth, evaporates the deodorizer faster, and increases fluid intake, leading to more use and quicker fill-up of the holding tank. A Friday service restores odor control, paper stock, and cleanliness before the weekend, preventing morale drops and work slowdowns. The tipping point is when you hear consistent complaints midweek or see avoidance behavior, that’s productivity loss. In hot climates like yours, twice-weekly service is common for crews over 30 or any site with high heat and no shade. The cost of added service is driven by frequency, travel, and labor, but it’s cheaper than crew frustration.

Deb's right about heat accelerating use and odor, but she didn't mention the holding tank capacity math. Two standard units hold about 100 to 140 gallons total for 45 people over five days. In Phoenix heat, workers drink more and urinate more, so tank fill happens faster. A Tuesday service means those units are near full by Thursday afternoon. The second service pays for itself when the tank volume per person per day drops below a tolerable level, which you've hit. Add Friday service or add a fourth unit to spread the load. The rental company's cost for twice-weekly service is mostly driver time and fuel, but it's fixed per visit, so more units on the same route can lower the per-unit cost.