Federal OSHA requires an adequate supply of potable water on every construction site, in closed containers with a tap, clearly marked, and with no shared cups. It doesn't set an amount. California, Washington and Maryland do: about one quart per worker per hour in the heat. That works out to 2 gallons per worker over an 8-hour shift, so a crew of 20 needs about 40 gallons a day.
Federal rule
These rules apply to construction sites nationwide, all year, regardless of heat.1
| Rule | What it means on site |
|---|---|
| Adequate supply of potable water | Enough drinking water for the whole crew, all shift. Potable means it meets state or local drinking standards or EPA's drinking water rules. |
| Portable containers close tightly and have a tap | No open buckets, and no dipping water out of the container. |
| Containers are clearly marked | Label it as drinking water and don't use it for anything else. |
| No common drinking cup | Single-use cups or the worker's own bottle. |
| Cups have a clean holder and a trash can | A sanitary container for unused cups and a receptacle for used ones. |
| No cross-connection with nonpotable water | Dust control or washout water stays separate, and nonpotable outlets get signs. |
State rules
A federal heat rule was proposed in August 2024, and the hearing record closed October 30, 2025. It's still a proposal, not a requirement.2 Several states already have their own.
| State | Amount | When it applies | Other details |
|---|---|---|---|
| California | One quart per employee per hour for the entire shift3 | All outdoor places of employment | Fresh, pure, suitably cool, free, and as close as practicable to where people work. A smaller starting supply is allowed with effective replenishment. |
| Washington | Opportunity to drink at least one quart per hour4 | At or above 80°F in most clothing, 52°F in nonbreathable clothing or PPE5 | Suitably cool and readily accessible at all times. The full shift supply doesn't have to be there at the start if replenishment is in place. |
| Maryland | At least 32 ounces per hour for each exposed employee6 | Employees covered by the state heat stress standard | Free, as close to the work area as practicable, and available at all times while work is being performed. |
Other states, including Oregon, have heat rules too. Check the rule where your site is.
How much to order
One quart per worker per hour is a quarter gallon. Over an 8-hour shift, that's 2 gallons per worker. Over a 10-hour shift, it's 2.5 gallons.
Multiply by the crew. Twenty workers on an 8-hour day need about 40 gallons. Fifty workers on 10-hour days need about 125 gallons a day. That's the number to plan deliveries around, even in a state without a quart rule, because it's the rate the states above settled on.
OSHA's own heat guidance says to provide cool water and, for work lasting more than two hours, electrolyte drinks as well.7 Water that sits in the sun all afternoon is water people stop drinking. Ice helps, and so does shade over the cooler.
Call with your crew size and shift length. We'll set up drinking water and ice delivery from local providers on a schedule that keeps up with the quart-an-hour rate.
Setup
Five things we'd check on any site, hot or not.
California and Maryland both say as close as practicable to where people are working.36 On a big site, that means more than one station.
Lidded coolers with a tap, marked as drinking water and used for nothing else.1
A cup dispenser and a can for used cups next to every cooler.
Shade over the station and ice on the delivery schedule. Cool water is what the state rules and OSHA's guidance call for.7
If you start the shift with less than the full day's supply, someone has to own the refill. Put a name on it. If hand washing is also on the list, see hand wash stations.
Common questions
Yes. 29 CFR 1926.51(a) requires an adequate supply of potable water at all places of employment, in containers that close tightly and have a tap, clearly marked, with no common drinking cup.
Federal OSHA doesn't set an amount. California and Washington require at least one quart per worker per hour in the heat, and Maryland requires 32 ounces per hour. That's 2 gallons per worker over an 8-hour shift.
The federal construction rule doesn't say. California and Washington require suitably cool water, and OSHA's heat guidance tells employers to provide cool water.
No. The common drinking cup is prohibited under 1926.51(a)(4). Use single-use cups with a sanitary dispenser and a trash can, or have workers bring their own bottles.
Not yet. OSHA proposed a heat injury and illness prevention rule in August 2024, and the post-hearing comment period ended October 30, 2025. It's still a proposal, so check your state's rules for now.
Yes. We arrange drinking water and ice delivery through local providers, alongside toilets and hand wash stations if you need them. Call sales at (888) 588-2607 with your crew size and schedule.
Local providers do the work; we hold the contract, own the problems, and send one bill. If a delivery gets missed, we contact the provider the same business day.
Read next
Sources