Detritus/How many units
Planning guide
The regulatory minimum and the number that keeps a site working are not always the same. Here is what changes the count, along with examples from sites we have served.
By Zach Nespinsky, VP, Revenue Operations. Updated October 9, 2026.
For construction, 29 CFR 1926.51, Table D-1, is the floor. Meet that count first. A long job often needs more units or more service than the table, because the table does not account for walking distance, peak weeks, or how often the units are pumped.
| Employees | Minimum toilet facilities |
|---|---|
| 20 or fewer | 1 toilet |
| More than 20 | 1 toilet seat and 1 urinal per 40 workers |
| 200 or more | 1 toilet seat and 1 urinal per 50 workers |
The same section requires adequate washing facilities where employees handle paints, coatings, herbicides, insecticides, or other harmful contaminants, and those facilities have to be near the work. It does not publish a hand-wash-station ratio. On our orders the range is about one station per three restroom units to one per eight. A 130-person construction site used eight units and three stations.
Table D-1 also does not set an accessible-unit count. Where a permit or contract requires an accessible toilet, plan on at least one unless the authority has confirmed otherwise in writing. The 2010 ADA Standards govern facilities that have to follow them. They are not a crew-size formula.
Meet the OSHA count, then account for how the site actually runs. A long project staffed to the bare minimum has a way of generating complaints by month three.
The operational number is driven by four things, in roughly this order of impact:
These are setups we have delivered, with the customer's reported headcount where available. Use them as reference points, not a sizing formula.
| Site | Headcount | What was delivered | Implied ratio |
|---|---|---|---|
| Construction site, commercial | 130 expected users | 8 standard units, 3 hand wash stations | ~1 unit per 16 people |
| Distribution warehouse, water outage | 250 people | Three 10-stall restroom trailers, 3 hand wash stations | ~1 stall per 8 people |
| Small crew, long duration | 4 laborers, 6 months | Units with interior sinks, serviced twice weekly | 1 unit per 4, higher service |
| Sports club, year-long | Not stated | 40 standard units, 5 hand wash stations | 8 units per station |
| Highway rest area, 12 months | Public | 4 standard plus 2 ADA units, weekly service | 1 in 3 units ADA |
| Park event, 45 days | 2,000 per day | Six to eight stall trailers, weekly servicing | Sized on peak concurrency |
| Five-week theatre production | Cast, crew, audience | 12 standard, 2 ADA, 2 portable sinks | 4 cleanings per week |
Detritus order records. Headcounts are as reported by the customer at time of order. These are delivered configurations, not recommendations for your specific site.
If people are complaining about cleanliness rather than lines, another weekly service may help more than another unit — and usually costs less. These are schedules we currently run:
| Frequency | Typical use |
|---|---|
| Weekly | Standard construction placement, moderate crew density |
| Twice weekly | High-density crews, hot climates, small unit counts |
| Three times weekly | Agricultural and multi-site operations with concentrated use |
| Four times weekly | Extended public-facing runs. We service a Monday, Wednesday, Friday and Sunday pattern on multi-week productions |
| Event-specific | Overnight cleaning before a peak morning. On weekend tournaments we drop Friday and clean Saturday night for Sunday use |
These show up after mobilization, when the original quantity is already on the site.
Crew count on a construction build is not flat. On one solar program monthly placements went from 4 to 90 within nine months. A fixed quantity set at mobilization was never going to last; without a scaling plan, the mismatch shows up as complaints instead of a change order.
Hand-wash stations are easy to miss, and inspectors tend not to miss them. They are a separate line item on nearly every provider's rate card, so make sure somebody asks.
Send peak crew count, duration, the site address, and whether the work is spread across a large parcel. We come back with a unit count, a service frequency, and pricing. If your headcount is going to move, say so and we will build the scaling in rather than pretending it is fixed.
Under 29 CFR 1926.51, Table D-1, a site needs one toilet for 20 or fewer employees, one toilet seat and one urinal per 40 workers above that, and one toilet seat and one urinal per 50 workers at 200 or more. That is the regulatory floor. A longer job often needs more service or more units than the table. The rule is published at osha.gov.
Start with the OSHA table, then consider the length of the job and service frequency. One hundred workers is above 20 and below 200, so Table D-1 calls for one toilet seat and one urinal per 40 workers. For longer projects, roughly one unit per 15 to 20 workers tends to hold up better than that floor. We supplied a 130-person construction site with eight standard units and three hand-wash stations, or about one unit per 16 people. Eight units serviced weekly and eight serviced twice weekly are not the same setup.
OSHA's construction rule requires adequate washing facilities where crews handle contaminants. It does not set a station-to-toilet ratio. Our orders commonly range from one hand-wash station per three units to one per eight. A 130-person construction site used eight units and three stations; a sports club order included 40 units and five stations. Food service, healthcare, and other health-code-sensitive sites usually need the higher ratio, and inspectors do check.
Event planning is driven by peak concurrency and duration rather than total attendance, because everyone queues at the same time. A park event expecting 2,000 people per day across 45 days was scoped around six to eight stall trailers rather than individual units. Multi-day events also need a service schedule built around the peak, including overnight cleaning before the busiest morning. Wedding and festival counts are on the event planning guide.
Yes. On a long placement, adding service can be cheaper than adding units, especially when the complaint is cleanliness rather than availability. Our schedules range from weekly to four times a week. For one five-week production, that meant service on Monday, Wednesday, Friday, and Sunday.
The OSHA toilet table does not set an accessible-unit count. A contract or permit often still requires one. Our orders have included two ADA units in a 14-unit event order, two in a six-unit highway rest-area placement, and ADA-accessible trailers for a residential building. Assume you need at least one unless the relevant authority has confirmed otherwise in writing.