Certification Action Line features questions and answers typical of those appearing in Water Quality Association (WQA) certification examinations. Some answers may not satisfy everyone or every condition.

1. What is total hardness of water in mg/L as CaCO3 when magnesium (Mg) is 10 mg/L and calcium (Ca) is 20 mg/L?
a) 10 mg/L
b) 30 mg/L
c) 41 mg/L
d) 91 mg/L

2. Adsorption operates on the principle of:
a) adhesion
b) chance collision
c) gravity
d) magnetic polarization

3. Trihalomethanes are formed when:
a) the water contains organic chemicals
b) the water contains large concentrations of inorganic chemicals
c) the filters are backwashed
d) chlorine reacts with humic and fulvic acids in water

4. The chemical formula for ferric oxide is:
a) FO
b) FeO
c) FeO2
d) Fe2O3

5. The term volatile can best be defined as:
a) a precipitate
b) capable of being easily attacked
c) highly explosive
d) turning to vapor easily

6. The amount of time a sample can be stored depends on:
a) the laboratory procedure being used
b) the stability of the constituent to be tested and whether the sample can be preserved
c) the temperature
d) whether the sample contains raw or treated water

7. Sodium thiosulfate crystals are placed in bacteriological sample bottles to:
a) hold pH at a constant value
b) kill any pathogens that may be present in the sample
c) neutralize any chlorine present in the sample
d) preserve the sample

8. Ferric oxide is:
a) a strong solution for purging bacterial growths
b) common rust
c) formed at the cathode
d) used for dissolving tubercules

9. Iron that remains in the ferrous state will:
a) be removed by the filters
b) pass through the filters
c) precipitate in the reaction tank
d) settle out

10. Water may be aerated by several methods, almost all of which involve:
a) covering the storage facilities
b) exposing a large surface area to the atmosphere
c) increasing the pressure
d) reducing its temperature