Residential Water Quality Testing Flashcards

A homeowner reports blue-green staining in sinks and tubs. Which water quality parameter should be tested FIRST?

Answer: Copper

Blue-green staining is a classic sign of elevated copper in water, often caused by corrosion of copper pipes.

Which water quality test is recommended for homes built before 1986 due to older plumbing materials?

Answer: Lead

Homes built before 1986 may have lead solder or lead pipes, making lead testing critical per EPA guidance.

When testing for lead at the tap using the EPA's 'first-draw' protocol, how long must the water sit stagnant before sampling?

Answer: At least 6 hours

The first-draw protocol requires at least 6 hours of stagnation to allow water contact with lead-containing plumbing before sampling.

Radon in residential drinking water is MOST concerning when the water source is:

Answer: A private well in a granite or uranium-rich bedrock area

Groundwater from wells in granite or uranium-rich geology can carry dissolved radon, which volatilizes during household use and becomes an inhalation hazard.

A customer's water test shows iron at 0.5 mg/L and manganese at 0.1 mg/L. Which aesthetic issue is MOST likely reported?

Answer: Black or dark brown staining on laundry and fixtures

Manganese at or above 0.05 mg/L commonly causes black or dark brown staining on fixtures, laundry, and dishwashers.

The Langelier Saturation Index (LSI) is used to predict water's tendency to:

Answer: Form or dissolve calcium carbonate scale

The LSI quantifies whether water is scale-forming (positive LSI) or corrosive/scale-dissolving (negative LSI) based on calcium carbonate equilibrium.

Which of the following volatile organic compounds (VOCs) is most commonly found in residential well water near gas stations or underground storage tanks?

Answer: Benzene

Benzene is a key gasoline component and the most commonly detected VOC in groundwater near leaking underground storage tanks.