MN Water Operator case studies
MN Water Operator · Put your knowledge to work in context.
The Minnesota Water Operator credential is a state certification for the people who run and maintain public drinking water systems - treatment plant operators, distribution system operators, and the small-system staff who often do both. Minnesota regulates drinking water through the Minnesota Department of Health, and the certification process is built around demonstrating that an operator can produce and deliver safe water while keeping the system in compliance. The MN Water Operator case studies are 5 cases and about 4,791 words.
1Storm Event at a Low-Alkalinity Conventional Plant
Your 4.2-mgd conventional plant (6-mgd design) treats a low-alkalinity river with alum coagulation, sedimentation, and six dual-media filters at 4 gpm/sf. Baseline raw water is 12 NTU, pH 7.6, alkalinity 85 mg/L, 8 °C, and alum runs 32 mg/L with a settled-water target under 2 NTU.
905 words, about 5 min2Chloramine Residual Collapse on a Dead-End Main
Your 4,800-connection system chloraminates at pH 8.2 with a 3.5:1 chlorine-to-ammonia ratio. Total chlorine leaving the plant is 1.05 mg/L; free ammonia is 0.10 mg/L.
977 words, about 5 min3Intake Pump Cavitating After Demand Growth
A horizontal split-case intake pump at River Station is rated 1,400 gpm at 95 ft TDH, driven by a 50-hp, 460-V motor (62 A nameplate, 1.15 service factor). Site elevation is about 1,000 ft and summer water temperature is 15 °C (vapor pressure about 0.25 psi).
1,005 words, about 5 min4E. coli Positive at a Restaurant Tap
Your system collects 25 routine samples per month and chlorinates to a free residual of about 0.5 mg/L at the plant. This morning the lab reports that yesterday's routine sample from a restaurant kitchen tap is E.
977 words, about 5 min5Wet Well Entry With a Marginal Gas Reading
A clogged pump at Lift Station 4 requires entry into a 6-ft diameter, 14-ft deep wet well. The crew's 4-gas meter was bump-tested 40 days ago and last calibrated six months ago.
927 words, about 5 min