Concrete washout captures rinse water and slurry from chutes, pumps, and tools
https://wiki-wire.win/index.php/Top_Concrete_Washout_Mistakes_Contractors_Must_Avoid
Concrete washout captures rinse water and slurry from chutes, pumps, and tools, preventing high-pH runoff from polluting soils, drains, and waterways on and around active construction sites.