NASCO Facility Operations & Maintenance 4

Question 1

A pool operator smells a strong chlorine odor near an indoor pool with high bather load. The most likely explanation is:

Accepted Answer

Elevated chloramine formation from swimmer waste

Answer

A strong 'chlorine smell' almost always indicates chloramines (combined chlorine) reacting with nitrogen from urine, sweat, and other organic matter — not excess free chlorine.

Question 2

What is breakpoint chlorination?

Accepted Answer

Adding enough chlorine to destroy all combined chlorine and reach a free residual

Answer

Breakpoint chlorination requires adding approximately 10 times the combined chlorine level in free chlorine to oxidize all chloramines and establish a free residual.

Question 3

Which type of pool drain cover is required under the Virginia Graeme Baker Act for public pools?

Accepted Answer

ANSI/APSP-16 certified anti-entrapment drain covers

Answer

The Virginia Graeme Baker Pool and Spa Safety Act mandates ASME/ANSI A112.19.8-certified anti-entrapment drain covers on all public pools and spas.

Question 4

How should pool chemicals be stored at an aquatic facility?

Accepted Answer

Oxidizers and chlorine compounds stored separately in ventilated, dry areas

Answer

Oxidizers and chlorine compounds can react violently if mixed; they must be stored separately in cool, dry, ventilated areas away from ignition sources.

Question 5

What does a multiport valve set to 'recirculate' do on a sand filter system?

Accepted Answer

Bypasses the filter and sends water directly through the pump and back to the pool

Answer

The recirculate setting bypasses the filter media, circulating pool water through the pump without filtration — used when adding chemicals for mixing.

(NASCO) National Aquatic Safety Company Aquatic Facility Operator Certification Practice Test

(NASCO) National Aquatic Safety Company Aquatic Facility Operator Certification Practice Test

NASCO Facility Operations & Maintenance 4