NASCO Facility Operations & Maintenance 3

Question 1

What does the Langelier Saturation Index (LSI) measure in pool water chemistry?

Accepted Answer

Water's tendency to be scale-forming or corrosive

Answer

The LSI calculates the balance of pH, alkalinity, calcium hardness, and temperature to predict whether water will deposit scale or corrode surfaces.

Question 2

A facility operator finds the pump is running but water flow to the pool is very low. What should be checked FIRST?

Accepted Answer

Pump strainer basket for blockage

Answer

A clogged pump strainer basket is the most common cause of reduced flow and should be the first point of inspection.

Question 3

What is the minimum recommended turnover rate for a public swimming pool?

Accepted Answer

Every 6 hours

Answer

Most public pool codes require all pool water to pass through the filtration system at least once every 6 hours to maintain water clarity and sanitation.

Question 4

Which hazard is MOST directly associated with high combined chlorine (chloramines) levels in an indoor pool?

Accepted Answer

Respiratory irritation for swimmers and staff

Answer

Chloramines are volatile compounds that off-gas into the air, causing eye, skin, and respiratory irritation — especially problematic in enclosed indoor facilities.

Question 5

What action should a pool operator take when total dissolved solids (TDS) exceed 1,500 ppm above the source water baseline?

Accepted Answer

Partially drain and refill with fresh water

Answer

Elevated TDS impairs chemical effectiveness and cannot be removed by filtration — draining and diluting with fresh water is the only remedy.

(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 3