CWEA LABORATORY ANALYST CERTIFICATION
EVALUATION TEST 2026 FULL QUESTIONS AND
CORRECT ANSWERS ALREADY PASSED
GRADED A+
Color Measurement. Answer: Measured using visual comparison
method
◉ Conductivity. Answer: Mobility of ions, conductivity is dependent
on viscosity
◉ Hardness Measurement. Answer: Using EDTA titrimetric method.
pH of sample is buffered to 10 +/- 0.1 and Eriochrome black T is
added as an indicator
◉ BOD Incubation. Answer: Incubate at 20 +/- 1 C without light for 5
days +/- 6 hours
◉ HPC Incubation. Answer: Incubate pour plates at 35 C for 48
hours. Humidity needs to be maintained so that agar plates will have
no moisture weight loss greater than 15%
◉ Instructions Clarification. Answer: Ask the author
,◉ Color Reporting. Answer: True and Apparent
◉ Chloride Measurement Methods. Answer: Argentometric and
mercuric nitrate
◉ Accuracy. Answer: The combination of bias and precision of an
analytical procedure, which reflects the closeness of a measured
value to a true value
◉ Acid. Answer: A compound which liberates hydrogen ions and has
a pH below 7
◉ Agar Medium. Answer: Used for Heterotrophic plate count
◉ Alkalinity Reporting. Answer: Alkalinity mg CaCO3/L
◉ Alkalinity Measurement. Answer: The carbonate, bicarbonate, and
hydroxide ion concentration found in water
◉ Alkalinity Definition. Answer: The measurement of a sample's
capacity to neutralize acid
, ◉ Total Dissolved Solids Analysis Procedure. Answer: 1. Stir sample
with magnetic stirrer and pipet measured volume onto glass fiber
filter with applied vacuum. 2. Wash with 3 successive 10 ml volumes
of reagent grade water. 3. Suction for 3 minutes after filtration is
complete. 4. Transfer total filtrate to weighed evaporating dish and
evaporate to dryness. 5. Dry evaporated sample for 1 hour in 180 +/-
2 degree C. 6. Cool and weigh to constant weight.
◉ Total Solids Analysis Procedure. Answer: 1. Choose sample
volume that will yield residue between 2.5 and 200 mg. 2. Dry
evaporated sample for 1 hour in 103-105 degree C oven. 3. Cool in
desiccator and weigh to constant weight.
◉ Total Suspended Solids Analysis Procedure. Answer: 1. Wet filter
to seat it. 2. Pipet measured volume to filter. 3. Wash filter with 3
successive 10 mL wash of reagent grade water and continue suction
for 3 minutes. 4. Dry for 1 hour in 103-105 degree C oven.
◉ Apparent Color. Answer: Includes dissolved and suspended solids
◉ Argentometric. Answer: Titration of sample with standard
solution of silver nitrate (AgNO3)
◉ Indicator. Answer: Chromate ions (CrO4)
EVALUATION TEST 2026 FULL QUESTIONS AND
CORRECT ANSWERS ALREADY PASSED
GRADED A+
Color Measurement. Answer: Measured using visual comparison
method
◉ Conductivity. Answer: Mobility of ions, conductivity is dependent
on viscosity
◉ Hardness Measurement. Answer: Using EDTA titrimetric method.
pH of sample is buffered to 10 +/- 0.1 and Eriochrome black T is
added as an indicator
◉ BOD Incubation. Answer: Incubate at 20 +/- 1 C without light for 5
days +/- 6 hours
◉ HPC Incubation. Answer: Incubate pour plates at 35 C for 48
hours. Humidity needs to be maintained so that agar plates will have
no moisture weight loss greater than 15%
◉ Instructions Clarification. Answer: Ask the author
,◉ Color Reporting. Answer: True and Apparent
◉ Chloride Measurement Methods. Answer: Argentometric and
mercuric nitrate
◉ Accuracy. Answer: The combination of bias and precision of an
analytical procedure, which reflects the closeness of a measured
value to a true value
◉ Acid. Answer: A compound which liberates hydrogen ions and has
a pH below 7
◉ Agar Medium. Answer: Used for Heterotrophic plate count
◉ Alkalinity Reporting. Answer: Alkalinity mg CaCO3/L
◉ Alkalinity Measurement. Answer: The carbonate, bicarbonate, and
hydroxide ion concentration found in water
◉ Alkalinity Definition. Answer: The measurement of a sample's
capacity to neutralize acid
, ◉ Total Dissolved Solids Analysis Procedure. Answer: 1. Stir sample
with magnetic stirrer and pipet measured volume onto glass fiber
filter with applied vacuum. 2. Wash with 3 successive 10 ml volumes
of reagent grade water. 3. Suction for 3 minutes after filtration is
complete. 4. Transfer total filtrate to weighed evaporating dish and
evaporate to dryness. 5. Dry evaporated sample for 1 hour in 180 +/-
2 degree C. 6. Cool and weigh to constant weight.
◉ Total Solids Analysis Procedure. Answer: 1. Choose sample
volume that will yield residue between 2.5 and 200 mg. 2. Dry
evaporated sample for 1 hour in 103-105 degree C oven. 3. Cool in
desiccator and weigh to constant weight.
◉ Total Suspended Solids Analysis Procedure. Answer: 1. Wet filter
to seat it. 2. Pipet measured volume to filter. 3. Wash filter with 3
successive 10 mL wash of reagent grade water and continue suction
for 3 minutes. 4. Dry for 1 hour in 103-105 degree C oven.
◉ Apparent Color. Answer: Includes dissolved and suspended solids
◉ Argentometric. Answer: Titration of sample with standard
solution of silver nitrate (AgNO3)
◉ Indicator. Answer: Chromate ions (CrO4)
