CWEA WASTEWATER LABORATORY ANALYST CERTIFICATION EXAM PRACTICE QUESTIONS AND ANSWERS 2026

CWEA WASTEWATER LATEST
LABORATORY ANALYST
CERTIFICATION EXAM
PRACTICE
Disposal of biosolids is covered under:


(a) 40 CFR 258
(b) 40 CFR 136
(c) 40 CFR 503
(d) 40 CFR 160 - ANSWERS-C


Explanation
40 CFR 503, Standards for the use or disposal of sewage sludge, covers
the disposal of biosolids. 40 CFR 258 is criteria for municipal solid
waste landfills. 40 CFR 136 is guidelines for establishing test procedures
for the analysis of pollutants. 40 CFR 160 is good laboratory practice
standards.


The proper collection and preservation for samples collected for mercury
analysis is:


(a) collect in a Mason® jar and send to the lab
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, CWEA WASTEWATER LATEST
LABORATORY ANALYST
CERTIFICATION EXAM
PRACTICE
(b) collect in a pre-cleaned glass or polyethylene container
(c) add acid
(d) add nitric acid to pH <2 - ANSWERS-B,D


Explanation
Sampling requirements (40 CFR 136.3, Table II) for mercury are:
container - polyethylene or glass; preservation - nitric acid to pH <2;
maximum holding time - 28 days.


The following parameters should never be sent to a commercial
laboratory because of maximum holding time violations:


(a) sulfate
(b) dissolved oxygen
(c) sulfite
(d) residual chlorine - ANSWERS-B,C,D


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