How Do You Plan a Concrete Pump Washout Area on Site?
By PumpX Team ·
Washing out a pump is the last job of the day and the one most often left to chance. Our concrete pump washout how-to covers the cleaning itself. This post is about the planning side: where the washout goes, how to build it, and how to get everyone to agree before the pour. Rules vary by council, state and country, so treat this as a practical checklist rather than legal advice.
Why it needs a plan
Wash water and slurry from concrete are highly alkaline and can harm waterways, soil and stormwater systems. Leftover cement also sets hard, which makes a mess of driveways, lawns and neighbours' properties. Many sites and regulators require containment. Even where they don't, a stray washout is a good way to upset a client.
A plan answers four questions: where, how big, who and what then.
Choose the location
Good washout sites are:
- Away from drains, gutters, creeks and bore heads. Stormwater pits go straight to waterways in many places.
- On stable, level ground. A bund on a slope can fail.
- Easy for the pump and the mixers to reach, without driving through the wash zone.
- Away from boundaries, trees and services. Roots and buried pipes don't mix with slurry.
- Clear of the area where outriggers will sit. See ground bearing and road plates.
If the site is too tight, discuss the alternative with the operator, such as taking the waste away in a sealed container.
Size and build
The volume depends on the pump, the line length and how much is left in the hopper. As a guide, ask the operator how much wash water they expect rather than guessing. Err on the generous side.
| Option | Pros | Cons |
|---|---|---|
| Lined pit or bund (heavy plastic sheet in a dug hollow or built frame) | Cheap, quick | Can tear; needs care to avoid leaks |
| Purpose-made washout tray or skip | Robust, reusable | Hire cost; delivery and collection |
| Truck-mounted wash container | Contained, portable | Operator must carry it |
| Return to the batch plant | Lets the supplier handle it | Needs agreement; logistics |
Whatever you use, make sure it is sturdy, sealed and stable. Don't let it overflow in rain; cover or monitor if weather is likely.
Agree responsibilities
Put these in writing before the day:
- Who supplies the washout? The builder, the pump hire company or the concrete supplier?
- Who monitors and empties it? Letting it sit until it hardens can make disposal easier for solids, but check local rules.
- Where does the waste go? Many areas require disposal at an approved facility. Don't dump it in the garden.
- What happens to the water? Some jurisdictions allow settled, neutralised water to be reused or discharged under conditions, while others forbid it. Check local requirements.
Mention it in your booking. Our ordering checklist and what is included in pump hire are good starting points for what the hire price covers.
Day-of tips
- Walk the site with the operator before the first truck arrives.
- Mark the washout with signage and cones so no one dumps leftover mix elsewhere.
- Keep a shovel and spare sheeting nearby for spills.
- Put the pump hose into the washout area before cleaning begins, not after.
- Keep kids, pets and passers-by clear.
- Don't hose the truck down in the street.
If the operator leaves concrete behind, that is a different problem; see what happens when an operator leaves concrete in the yard.
Cold and wet weather
Rain can overfill a pit, and frost can freeze water in a container or the line. Plan a covered or drained arrangement if the weather is unsettled. See winter pumping tips.
Safety
- Slurry is caustic. Wear gloves, eye protection and long sleeves, and rinse skin that gets wet.
- Don't open pressurised couplings to flush a blockage into the pit.
- Watch for slips around the wet zone.
- Keep the boom clear of overhead lines while cleaning.
A simple washout plan template
Even a one-paragraph plan helps. Write down the washout location (a marked spot on the site plan), the containment type and size, the person responsible for supplying it, the person responsible for emptying it, and the approved disposal route. Add the operator's phone number and the site supervisor's. Send it to the builder, the pump company and the concrete supplier the day before. If anyone objects, you have time to fix it. On small residential jobs this might be a text message, and on larger sites it belongs in the pour permit or method statement. Either way, the act of writing it down is what stops the "I thought you were bringing one" conversation at four in the afternoon with a hopper full of slurry.
Key takeaways
- Plan the washout location and size before pour day, not after.
- Keep it away from drains, waterways and traffic.
- Agree who supplies, monitors and empties it, and where the waste goes.
- Check local rules, as disposal requirements vary.
- Protect your skin and eyes from alkaline slurry.
Find pump operators who include washout containment in their service on PumpX: /services.
Original question on Reddit: r/Concrete: Pump washout plans