Which is not an authorized non-storm water discharge source?

Which is not an authorized non-storm water discharge source?

• A. Contaminated groundwater from dewatering
• B. Dechlorinated potable water sources such as Fire Hydrant Flushing
• C. Dust Control
• D. Uncontaminated ground water from dewatering

Answer: (A)

Non-storm water discharges at a construction site aren’t allowed by default—you must have an authorized source under the permit. Contaminated groundwater from dewatering isn’t authorized because pumping and then discharging water that carries site pollutants would pollute the stormwater system; it would require treatment or proper disposal instead of a straight discharge. The other options are considered permissible sources because they involve water that is either treated or inherently non-polluting: dechlorinated potable water used for activities like hydrant flushing is allowed since removing chlorine reduces ecological harm; dust control water is allowed when used for suppression and managed to avoid contaminating runoff; and uncontaminated groundwater from dewatering is acceptable because it’s native groundwater without site-derived contaminants.

Non-storm water discharges at a construction site aren’t allowed by default—you must have an authorized source under the permit. Contaminated groundwater from dewatering isn’t authorized because pumping and then discharging water that carries site pollutants would pollute the stormwater system; it would require treatment or proper disposal instead of a straight discharge. The other options are considered permissible sources because they involve water that is either treated or inherently non-polluting: dechlorinated potable water used for activities like hydrant flushing is allowed since removing chlorine reduces ecological harm; dust control water is allowed when used for suppression and managed to avoid contaminating runoff; and uncontaminated groundwater from dewatering is acceptable because it’s native groundwater without site-derived contaminants.