Wastewater Lab and Sampling Questions
Laboratory Analysis is 10 questions on WPI’s Wastewater Treatment Class I and II exams; sampling and simple analysis are part of California’s Grade I exam.
100 questions in the official content counts, with a score for every area and an explanation for every option.
Or try the free wastewater lab drill- 27 original wastewater lab questions, every option explained
- Tested on 6 of our 25 practice exams
What pH range does the federal secondary treatment standard require for effluent, unless an exception applies?
What our wastewater lab questions cover
- Grab versus flow-proportional composite samples
- Preservation and holding times
- BOD5 dilutions and QC, TSS and VSS, settleable solids
- DO probes, pH and bacterial indicators
- Chain of custody, bench sheets and records
This list is our own summary, written for practice. The exam owners publish their outlines: California’s Expected Range of Knowledge, TCEQ’s Need-to-Know Criteria and WPI’s Need-to-Know Criteria.
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100 questions in the official content counts, with a score for every area and an explanation for every option.
Or try the free wastewater lab drillIdeas the questions test most
- pH, DO and chlorine are immediate grab tests.
- BOD5: 5 days at 20°C.
- TSS filters dry at 103–105°C.
- Keep composites at 6°C or below.
Start the free wastewater lab drill · Wastewater Treatment Class I practice test · California Wastewater Grade I practice test · California Wastewater Grade II practice test · TCEQ Class D Wastewater practice test · TCEQ Class C Wastewater practice test · Wastewater Treatment Class II practice test
Common questions
Which tests use composite samples?
BOD and TSS are usually run on flow-proportional composite samples; pH, DO, chlorine residual and bacteria use grab samples.
What is the BOD holding time?
48 hours, kept at 6°C or below, under the 40 CFR Part 136 table.
100 questions in the official content counts, with a score for every area and an explanation for every option.
Or try the free wastewater lab drillMore operator topics
Outlines used for these questions: Expected Range of Knowledge, Drinking Water Treatment Exam (rev. 4/2020, PDF) · Expected Range of Knowledge, Drinking Water Distribution Exam (rev. 4/2020, PDF) · TCEQ: Need-to-Know Criteria for public water system operators · TCEQ: What applicants for wastewater licenses need to know · WPI: 2025 Need-to-Know Criteria.
Game Assessment Prep is an independent practice site, not affiliated with or endorsed by Water Professionals International (WPI, formerly ABC), the California State Water Resources Control Board or the Texas Commission on Environmental Quality. Every question is original; none is taken from a certification exam, an official study guide or another prep provider.