CWEA GRADE 1 LAB ANALYST EXAM 2026-2027
ACTUAL TEST BANK EXAM 400 QUESTIONS AND
CORRECT DETAILED ANSWERS WITH RATIONALES
|A+ GRADE \LATEST UPDATE 2026
The incubator for the BOD determination should be monitored and recorded
daily. The incubator temperature should be:
ANSWERS: 20 degrees +/-1 degree C
Laboratory data mistakes may be corrected by:
ANSWERS: lining out the mistake with pen and writing the correct answer to the
side of the first with analyst initials and date
The sample receiving log must record time and date sampled:
ANSWERS: sample collector, nature of sample, analyses to be performed,
preservatives, condition of sample and sample recipient.
Hood flow should be monitored and documented at:
ANSWERS: 100 linear feet per minute
,During an acid base titration, the titrant is added to the sample with a:
ANSWERS: Buret
Separatory funnels are designed to facilitate liquid-liquid extractions. Liquid-
liquid extraction can be used to separate
ANSWERS: organic analytes from the water by partitioning them into an organic
solvent
At a given temperature the intensity of the acidic or basic character of a solution
is indicated by
ANSWERS: pH or Hydrogen ion activity
A solution with a pH of 5 has a concentration of hydrogen ions that is how many
times higher than a solution with a pH if 7?
ANSWERS: 100 times higher
A pH measurement requires the following:
ANSWERS: a voltmeter, glass pH electrode, reference electrode, and temperature
compensating device
Conductance measurements are temperature compensated to:
ANSWERS: 25.0 C
,The conductivity meter is calibrated with:
ANSWERS: .0100 N potassium chloride standard
Alkalinity is reported as:
ANSWERS: alkalinity, mg CaCO3/L
The hardness determination by EDTA titration measures:
ANSWERS: Calcium and Magnesium
The indicator for the hardness determination is:
ANSWERS: eriochrome Black T
EPA acceptable primary standards for the turbidity determination include:
ANSWERS: formazine only
COD
ANSWERS: ((Blank-Sample) x M x 8000))/ml Sample
The Biochemical Oxygen Demand determination is an empirical test in which
standardized laboratory procedures are used to:
ANSWERS: determine the relative oxygen requirements of wastewaters,
effluents and polluted waters.
, Sample pretreatment for the BOD determination includes
ANSWERS: assuring that the samples are neutralized to a pH range between 6.5
and 7.5 and that any residual chlorine has been dechlorinated
The process designed to kill most microorganisms in wastewater, including
essentially all pathogenic bacteria is called:
ANSWERS: disinfection
Fecal coliform bacteria:
ANSWERS: are bacteria found in the feces of warm blooded animals.
The definition for the total coliform group is
ANSWERS: all of the aerobic and facultative anaerobic, gram-negative, non-
spore-forming rod shaped bacteria that ferment lactose in 24-48 hours at 35
C
Laboratory test results for an individual environmental sample within an
analytical batch may be rejected when:
ANSWERS: a known error has occurred
Precision is measured by
ANSWERS: analyzing replicate samples
ACTUAL TEST BANK EXAM 400 QUESTIONS AND
CORRECT DETAILED ANSWERS WITH RATIONALES
|A+ GRADE \LATEST UPDATE 2026
The incubator for the BOD determination should be monitored and recorded
daily. The incubator temperature should be:
ANSWERS: 20 degrees +/-1 degree C
Laboratory data mistakes may be corrected by:
ANSWERS: lining out the mistake with pen and writing the correct answer to the
side of the first with analyst initials and date
The sample receiving log must record time and date sampled:
ANSWERS: sample collector, nature of sample, analyses to be performed,
preservatives, condition of sample and sample recipient.
Hood flow should be monitored and documented at:
ANSWERS: 100 linear feet per minute
,During an acid base titration, the titrant is added to the sample with a:
ANSWERS: Buret
Separatory funnels are designed to facilitate liquid-liquid extractions. Liquid-
liquid extraction can be used to separate
ANSWERS: organic analytes from the water by partitioning them into an organic
solvent
At a given temperature the intensity of the acidic or basic character of a solution
is indicated by
ANSWERS: pH or Hydrogen ion activity
A solution with a pH of 5 has a concentration of hydrogen ions that is how many
times higher than a solution with a pH if 7?
ANSWERS: 100 times higher
A pH measurement requires the following:
ANSWERS: a voltmeter, glass pH electrode, reference electrode, and temperature
compensating device
Conductance measurements are temperature compensated to:
ANSWERS: 25.0 C
,The conductivity meter is calibrated with:
ANSWERS: .0100 N potassium chloride standard
Alkalinity is reported as:
ANSWERS: alkalinity, mg CaCO3/L
The hardness determination by EDTA titration measures:
ANSWERS: Calcium and Magnesium
The indicator for the hardness determination is:
ANSWERS: eriochrome Black T
EPA acceptable primary standards for the turbidity determination include:
ANSWERS: formazine only
COD
ANSWERS: ((Blank-Sample) x M x 8000))/ml Sample
The Biochemical Oxygen Demand determination is an empirical test in which
standardized laboratory procedures are used to:
ANSWERS: determine the relative oxygen requirements of wastewaters,
effluents and polluted waters.
, Sample pretreatment for the BOD determination includes
ANSWERS: assuring that the samples are neutralized to a pH range between 6.5
and 7.5 and that any residual chlorine has been dechlorinated
The process designed to kill most microorganisms in wastewater, including
essentially all pathogenic bacteria is called:
ANSWERS: disinfection
Fecal coliform bacteria:
ANSWERS: are bacteria found in the feces of warm blooded animals.
The definition for the total coliform group is
ANSWERS: all of the aerobic and facultative anaerobic, gram-negative, non-
spore-forming rod shaped bacteria that ferment lactose in 24-48 hours at 35
C
Laboratory test results for an individual environmental sample within an
analytical batch may be rejected when:
ANSWERS: a known error has occurred
Precision is measured by
ANSWERS: analyzing replicate samples
