Typical problems associated with ash basin operations involve which contaminants?

• A. dissolved metals and fly ash
• B. nitrates and phosphates
• C. oil and grease
• D. bacteria and viruses

Answer: (A)

Ash basins deal with residues from combustion, especially coal ash, which brings two main types of contaminants into the water: dissolved metals and fine particulate matter known as fly ash. The ash contains metals that can leach into the basin water when it comes into contact with water, pH changes, or chemical reactions, so metals appear as dissolved contaminants. At the same time, the very fine particles in the ash—fly ash—can become suspended or settle out, causing solids-related issues like turbidity and sedimentation. This combination—metals dissolved into solution and the presence of fly ash solids—is the typical contamination pattern in ash basins. The other options describe contaminants more characteristic of other wastewater sources (nutrients from agricultural runoff, oil and grease from petroleum sources, or microbes from sanitary waste), not the principal concerns for coal ash basin operations.