CWS Point-of-Use vs Point-of-Entry Systems 3

Question 1

A customer's water report shows high levels of arsenic only in drinking water samples. Which treatment approach does the WQA typically recommend first?

Accepted Answer

POU reverse osmosis or POU anion exchange

Answer

For arsenic reduction, a POU RO or POU anion exchange (for arsenate) is commonly recommended because treatment at the drinking outlet is highly effective and avoids whole-house treatment costs.

Question 2

In a POE system serving a single-family home, the treatment device is typically installed:

Accepted Answer

On the cold-water line after the pressure tank or meter

Answer

POE equipment is placed on the main supply line—usually after the pressure tank (private well) or after the meter (municipal)—so it treats all water entering the home.

Question 3

Which of the following contaminants is BEST addressed by a POE system rather than a POU system?

Accepted Answer

Hydrogen sulfide causing odor from all hot and cold faucets

Answer

Hydrogen sulfide that affects all fixtures—including showers where inhalation is a concern—warrants a whole-house POE treatment solution.

Question 4

A POU drinking water system is certified under NSF/ANSI Standard 58. This standard covers:

Accepted Answer

Reverse osmosis drinking water treatment systems

Answer

NSF/ANSI 58 is the standard for reverse osmosis drinking water treatment systems, covering contaminant reduction, structural integrity, and materials safety.

Question 5

When comparing maintenance requirements, POE systems generally require:

Accepted Answer

More frequent filter changes because they handle larger volumes of water

Answer

POE systems treat all household water, exposing media and filters to higher total volumes, which typically requires more frequent or larger-scale media replenishment and backwashing.

(CWS) Certified Water Specialist Practice Test

(CWS) Certified Water Specialist Practice Test

CWS Point-of-Use vs Point-of-Entry Systems 3