Which of the following is a required method for handling concrete wash water?

• A. Poured onto the ground to infiltrate.
• B. Discharged directly to the storm sewer after mixing with sediment.
• C. Directed into a leak-proof container or a leak-proof settling basin.
• D. Allowed to overflow to prevent backup.

Answer: (D)

Concrete wash water contains cementitious fines and other materials that can harm water quality if released untreated. The required practice is to capture it in a leak-proof container or a leak-proof settling basin. This containment prevents wash water from infiltrating soil, running into the storm sewer, or spreading solids that can clog or contaminate waterways. From there, the water can be treated or hauled away for proper disposal in accordance with local permits and regulations.

Infiltrating wash water on the ground is unsafe because cement fines can harden in the soil, disrupt groundwater chemistry, and contaminate surface water. Discharging directly to the storm sewer after mixing with sediment bypasses needed treatment and still releases pollutants. Allowing overflow defeats containment and creates spill and environmental risks.