Under the Maricopa County code, a construction site needs one toilet per 20 people, within 200 feet of each work area. Arizona outdoor workers are also covered by new statewide heat-safety rules enforced by ADOSH. Confirm both with the county and the Industrial Commission of Arizona before you set a count.
Key takeaways
- The Maricopa County code asks for one toilet per 20 people on a construction site, placed within 200 feet of each work area.
- A crew of 60 needs at least three toilets under that ratio, and a spread-out site needs them in clusters near each work area, not all at the gate.
- An August 1, 2026 news report said Arizona outdoor workers are covered by first-ever statewide heat-safety rules enforced by ADOSH; the rule text and what it requires of toilets or water have not been confirmed here.
- Many Phoenix-area providers suggest more frequent servicing in peak summer, with twice-weekly visits often mentioned as a practical baseline; that is common advice, not a rule.
- Federal OSHA publishes its own sanitation and heat guidance for employers; it is the source for those details, not this site.
What does the county code require on a construction site?
The Maricopa County Environmental Health Code asks for one toilet per 20 people on construction sites, within 200 feet of each work area. The copy we found is dated 2011 and may have been amended, so confirm the figure with the county and your safety lead before you finalize a count.
The ratio is a minimum. It counts people, so include every trade, the general contractor's staff, inspectors who are regularly on site and delivery drivers who stay. The 200-foot figure is measured from each work area, which on a big site means more than one cluster.
The code also describes the units themselves: smooth, nonabsorbent floors, a vented tank and bowl, and light-coloured, easily cleaned seats, walls and ceilings. A provider that rents units in the county works under a county permit, with fees tied to the number of toilets.
Because the figure appears in a county health code, it is the number a county inspector would start from. Your own contractor, owner or insurer may ask for more than the county does, and a general contractor's safety plan often sets its own count. The higher number governs in practice.
How many toilets does my crew need?
Divide your peak headcount by 20 and round up, then check the distance to each work area. A crew of 45 needs at least three. If the site is large or the work areas are far apart, add clusters. The contractor and the authority for your job confirm the count.
Peak headcount matters more than average. A site that has ten people most days and sixty on the day of a concrete pour needs units for the sixty, or a plan to add units for the pour.
Remember to include the periods when the crew peaks. A site with a steady twenty people and a monthly delivery of thirty extra workers for a pour needs a plan for the monthly peak, not the steady number.
| Peak crew on site | Minimum toilets (1 per 20) | Clusters to consider |
|---|---|---|
| 15 | 1 | One, near the work |
| 40 | 2 | One or two, depending on the lot |
| 65 | 4 | Two, near different work areas |
| 120 | 6 | Two or three, with a break-area cluster |
| 250 | 13 | Three or more across a large footprint |
What are Arizona's new heat-safety rules?
An August 1, 2026 news report said Arizona outdoor workers are now covered by first-ever statewide heat-safety rules enforced by ADOSH, the Arizona Division of Occupational Safety and Health. We have not confirmed the rule text, the effective date or what it requires of toilets or water.
Employers should check the Industrial Commission of Arizona and ADOSH for what applies to their sites. Federal OSHA also publishes heat guidance for employers, and it is the place to read it. This site is not a source for compliance.
This guide makes no claim about what heat does to a person. For that, ask a doctor.
How should summer change the plan?
Heat speeds waste breakdown and odour and weakens deodoriser, so many Phoenix-area providers suggest more frequent servicing in peak summer. Shade and ventilation help. A restroom trailer with cooling is the upgrade for long jobs. Phoenix logged 70 days at or above 110 F in 2024.
Crews start early in summer, so a service visit the afternoon before leaves units fresh at dawn. Put units in shade where the site allows, and keep the vent clear. Ask the provider about a handwash station, and about refills, since water in the sun gets hot.
The summer heat guide covers siting and servicing, and the construction toilets page covers the booking.
Plan the day around the heat as well as the units. A service visit the afternoon before leaves tanks empty at dawn, and a handwash station placed in shade and filled before the shift will have cool enough water when the crew breaks.
How do big West Valley sites change the plan?
They spread the crew across a large footprint, so toilets go in several clusters and move as the building rises. About 21.4 million square feet of industrial space was under construction in metro Phoenix in early 2026, mostly in the West Valley, according to an industrial market report.
West Phoenix is reported as the most active zone for new warehouse and distribution building, and Glendale planned a three-building, 471,000 square foot park on the 101 corridor, with construction starting in the third quarter of 2026. Avondale is reported as pivoting toward data centres and advanced technology campuses.
Walk the site with the provider, mark the work areas and update the layout at each phase. See the industrial and warehouse page.
What should a site manager keep on file, and ask the provider?
The headcount by day, the layout of the toilets with distances to work areas, the servicing schedule and a log of visits, plus the provider's quote. If an inspector or an owner asks about sanitation, a one-page record answers it quickly.
None of this replaces the rules. It shows that someone checked them.
A provider that answers these clearly is easier to work with for months. One that is vague at the quote stage will be vaguer when something goes wrong.
If the owner or lender audits site conditions, the record also helps there. A short note that says who counted, on what date and against which figure is worth more than a long memory.
- Peak headcount by phase, updated weekly
- A site map with toilets and 200-foot circles
- Servicing days and a log of visits
- The written quote and any change in writing
- Contact details for the provider and the safety lead
- How was the number of units worked out, and how would it change if the crew grew?
- What servicing schedule does it suggest for summer and for winter?
- How quickly can it add or move units, and what does that cost?
- What does it need from the site: access, ground, gate widths, shade?
- How does it confirm that a visit happened?
Where do toilets go on a desert construction site?
On firm, level ground within 200 feet of each work area, off the haul road, away from washes and low areas, and with a clear truck approach. Shade helps in summer. Tell the provider where concrete trucks, cranes and deliveries will block access.
Valley sites are often graded dirt or gravel, which holds a unit well when it is dry and compacted. Loose fill and fresh grading are poor places. Washes that look dry can fill in minutes during a monsoon storm, so units do not belong in or beside one.
Plan for movement. As the building rises, work areas shift and a unit that was close in March may be far in June. Ask the provider how it handles moves and what a move costs.
What does a build look like phase by phase?
Headcount, and so the toilet count, changes with each phase. Early site work may have a small crew, framing and roofing swell it, and fit-out brings many trades at once. Plan units for each phase and tell the provider when the next one starts.
The pattern matters more than the numbers. Tell the provider when each phase begins, and ask how much notice it needs to add units. A site that waits until the crew is already waiting in line has left it late.
Winter is easier on servicing than summer, but the county ratio does not change with the season. The summer difference is in how often the units are serviced and where they stand.
Foundations, framing, roofing and finishing bring different trades and different numbers. A single count at the start of a six-month build is almost certain to be wrong at some point. Put a headcount review on the weekly meeting list.
Split shifts help the toilets only a little. If a night crew and a day crew overlap for an hour, count them together for that hour. Ask the provider about servicing between shifts, so units are fresh when each crew arrives.
| Phase | Example peak crew | Minimum toilets (1 per 20) | Planning note |
|---|---|---|---|
| Site prep and grading | 12 | 1 | One cluster by the gate; keep it off the haul road |
| Foundations and slab | 30 | 2 | Add a unit before a pour day |
| Framing or steel | 70 | 4 | Two clusters near different work areas |
| Roofing and envelope | 90 | 5 | Shade and extra servicing in summer |
| Fit-out and finishes | 140 | 7 | Clusters by each building, plus a trailer for a break area |
Frequently asked questions
Is one toilet per 20 workers a federal or a county figure?
It is the Maricopa County figure in the code we found. Federal OSHA has its own sanitation requirements, which we have not reviewed here, so check OSHA directly.
Do subcontractors count toward the total?
Yes. Everyone working on the site counts, so the general contractor should include every trade in the headcount.
Do I need a handwash station?
It is a sensible addition beside the toilets, and a county handwash set-up applies to food events. Ask your safety lead about your site.
Who enforces the heat-safety rules?
According to the August 2026 report, ADOSH. Check the Industrial Commission of Arizona for the rules and what they require.
Can the line certify that my count meets the rules?
No. Phoenix Porta Potty Rental connects you with a provider, and the provider can recommend a number. The contractor and the authority for your job decide what applies.
Sources
- Maricopa County Environmental Health Code, Chapter 2 Section 6 – Chemical Toilets, Portable Restroom Units, Portable Waste Holding Tanks (PDF)
- Wikipedia – Phoenix, Arizona
- Wikipedia – Portable toilet
This guide is general information for Maricopa County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.