A facility is conditionally exempt from silver recovery requirements if it generates less than 500 gallons per month of silver-containing solution which is: 1) hazardous only for silver 2) treated on-site within 90 days 3) silver concentration is reduced to less than 5 mg/L. Which statements are correct?

• A. 1 and 2
• B. 1 and 3
• C. 2 and 3
• D. 1, 2, and 3

Answer: (D)

This conditional exemption applies only when silver-bearing waste is kept at a small scale and managed in a way that minimizes risk. The waste must be hazardous only for silver, meaning there aren’t other hazardous constituents driving the regulation. It also must be generated in a small amount—less than 500 gallons per month. In addition, on-site treatment must occur within 90 days to prevent long-term accumulation, and the silver concentration must be reduced to below 5 mg/L so the residual silver is kept at a very low level. When all three conditions are met, the facility can qualify for the exemption from the full silver recovery requirements. Therefore, all three statements are correct.