Water Chemistry & Contaminant Identification Flashcards

Which water quality parameter indicates the concentration of calcium and magnesium ions expressed as CaCO₃?

Answer: Total Hardness

Total hardness represents the combined concentration of calcium and magnesium ions, conventionally expressed as equivalent CaCO₃ in mg/L.

Lead contamination in drinking water most often enters the water supply through:

Answer: Corrosion of lead service lines and plumbing

Lead typically enters drinking water through corrosion of lead service lines, solder, and fixtures rather than from source water.

The Ryznar Stability Index (RSI) value of 6.0 indicates that water is:

Answer: Balanced (no tendency to scale or corrode)

An RSI of 6.0 indicates water that is neither scale-forming nor corrosive, representing the balanced point.

Which analytical method is most appropriate for measuring very low concentrations of volatile organic compounds (VOCs) in water?

Answer: Gas chromatography/mass spectrometry (GC/MS)

GC/MS is the standard analytical method for detecting and quantifying trace levels of VOCs in water samples.

Coliform bacteria in water testing serve as:

Answer: Indicator organisms suggesting possible fecal contamination

Coliforms are used as indicator organisms; their presence suggests possible fecal contamination and the potential for pathogenic microorganisms.

What is the primary concern with elevated manganese levels in drinking water?

Answer: Black staining, taste issues, and potential neurological effects at high concentrations

Elevated manganese causes black staining on fixtures and laundry, bitter taste, and at higher levels may affect neurological development.

Oxidation-Reduction Potential (ORP) in water is measured in:

Answer: mV (millivolts)

ORP is measured in millivolts (mV) and indicates whether water is in an oxidizing or reducing state.