Free NEHA Water Quality Questions and Answers

Question 1

Which of the following is the most common method used to disinfect drinking water?

Accepted Answer

Chlorination

Answer

Chlorination is the most widely used method to disinfect drinking water, killing bacteria, viruses, and other pathogens.

Question 2

What is the maximum contaminant level (MCL) for lead in drinking water according to the U.S. Environmental Protection Agency (EPA)?

Accepted Answer

0.015 mg/L

Answer

The EPA's MCL for lead in drinking water is 0.015 mg/L (15 parts per billion) to protect against the harmful effects of lead exposure.

Question 3

What does pH measure in water quality?

Accepted Answer

The acidity or alkalinity of water

Answer

pH is a measure of how acidic or basic (alkaline) water is, with values ranging from 0 (most acidic) to 14 (most basic).

Question 4

Which of the following contaminants is often responsible for causing algal blooms in water bodies?

Accepted Answer

Nitrates and phosphates

Answer

High levels of nitrates and phosphates in water can cause excessive algae growth, leading to harmful algal blooms and water quality issues.

Question 5

What is the main health concern associated with high levels of nitrates in drinking water?

Accepted Answer

Blue baby syndrome (methemoglobinemia)

Answer

High nitrate levels in drinking water can reduce the oxygen-carrying capacity of blood in infants, leading to blue baby syndrome.

NEHA - National Environmental Health Association Practice Test