1|Page
CWEA Water Quality Laboratory Analyst Certification
Exam Practice Verified Questions And Correct
Answers (Verified Answers) Plus Rationale 2026/2027
Q&A| Instant Download Pdf
Weights used for calibrating the analytical balance? -
Answer-ASTM Class 2 weights
*Also balance must be serviced by a tech at least once a
year*
Three methods for water purification for reagent grade
water? - Answer-Distillation- reduces inorganic salts, but
this is about all.
Deionization Cartridges- remove charged ions and
particles from water. Adds organic material to water.
Activated Carbon Cartridges- remove organic
contaminants. Adds metal ions to the water.
*water intended for organic determination needs to be
carbon-filtered last*
What are the 2 classifications of purity for reagent water?
Who created this? - Answer-ASTM established two types,
Type 1- pure Type 2-less pure.
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What three specifications must reagent grade water meet?
What is the yearly requirement? - Answer-Conductivity of
<2 mmhos/cm at 25 C, monthly.
Total Cl of <1 mg/l, monthly.
Heterotrophic Plate Count (HPC) of < 500 CFU/mL.
Yearly a Bacteria growth rate (BGR) and metal test.
What is BGR? - Answer-Bacteria growth rate (BGR)
makes sure the water is suitable for bacteria life.
Seven autoclave requirements? - Answer-1. Internal heat
source.
2. Temp gauge with sensor on exhaust.
3. Pressure gauge
4. Operational safety valve
5. Should maintain sterilization temp through whole cycle.
6. Should complete whole cycle in 45 minutes (for 15 min.
sterilization time)
7. Should depressurize slowly.
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Thermometers must be graduated in ___ increments? -
Answer-0.5 C BUT 0.2 C for 44.5 incubation.
How often do you calibrate your thermometer and using
which organization? - Answer-Annually with an NIST
standard. If differs more than 1 C then it must be
discarded. Reference thermometers should be
recalibrated every 5 years.
Explain Beer's Law - Answer-The law states that the
concentration of a chemical is directly proportional to the
absorbance of a solution. 0 absorbance = 100%
transmittanceColorimeter is typically used for this.The
darker the color, the more absorbance. Thus, the darker
the test the higher the concentration. The only test that
does not follow this rule is Fluoride.
What are the standards for specific gravity? - Answer-
Solids and liquids- water 1g/cm3
Gasses- air 1.29 g/L
Bonding occurs because of ________ - Answer-valence
electrons.
CWEA Water Quality Laboratory Analyst Certification
Exam Practice Verified Questions And Correct
Answers (Verified Answers) Plus Rationale 2026/2027
Q&A| Instant Download Pdf
Weights used for calibrating the analytical balance? -
Answer-ASTM Class 2 weights
*Also balance must be serviced by a tech at least once a
year*
Three methods for water purification for reagent grade
water? - Answer-Distillation- reduces inorganic salts, but
this is about all.
Deionization Cartridges- remove charged ions and
particles from water. Adds organic material to water.
Activated Carbon Cartridges- remove organic
contaminants. Adds metal ions to the water.
*water intended for organic determination needs to be
carbon-filtered last*
What are the 2 classifications of purity for reagent water?
Who created this? - Answer-ASTM established two types,
Type 1- pure Type 2-less pure.
,2|Page
What three specifications must reagent grade water meet?
What is the yearly requirement? - Answer-Conductivity of
<2 mmhos/cm at 25 C, monthly.
Total Cl of <1 mg/l, monthly.
Heterotrophic Plate Count (HPC) of < 500 CFU/mL.
Yearly a Bacteria growth rate (BGR) and metal test.
What is BGR? - Answer-Bacteria growth rate (BGR)
makes sure the water is suitable for bacteria life.
Seven autoclave requirements? - Answer-1. Internal heat
source.
2. Temp gauge with sensor on exhaust.
3. Pressure gauge
4. Operational safety valve
5. Should maintain sterilization temp through whole cycle.
6. Should complete whole cycle in 45 minutes (for 15 min.
sterilization time)
7. Should depressurize slowly.
, 3|Page
Thermometers must be graduated in ___ increments? -
Answer-0.5 C BUT 0.2 C for 44.5 incubation.
How often do you calibrate your thermometer and using
which organization? - Answer-Annually with an NIST
standard. If differs more than 1 C then it must be
discarded. Reference thermometers should be
recalibrated every 5 years.
Explain Beer's Law - Answer-The law states that the
concentration of a chemical is directly proportional to the
absorbance of a solution. 0 absorbance = 100%
transmittanceColorimeter is typically used for this.The
darker the color, the more absorbance. Thus, the darker
the test the higher the concentration. The only test that
does not follow this rule is Fluoride.
What are the standards for specific gravity? - Answer-
Solids and liquids- water 1g/cm3
Gasses- air 1.29 g/L
Bonding occurs because of ________ - Answer-valence
electrons.
