CWS Residential Water Quality Testing 3

Question 1

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

Accepted Answer

Copper

Answer

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

Question 2

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

Accepted Answer

Lead

Answer

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

Question 3

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

Accepted Answer

At least 6 hours

Answer

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

Question 4

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

Accepted Answer

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

Answer

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

Question 5

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?

Accepted Answer

Black or dark brown staining on laundry and fixtures

Answer

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

(CWS) Certified Water Specialist Practice Test

(CWS) Certified Water Specialist Practice Test

CWS Residential Water Quality Testing 3