Wastewater Treatment Operator Class III case studies
Wastewater Treatment Operator Class III · Put your knowledge to work in context.
Class III Wastewater Treatment Operator certification is the mid-tier credential in most state operator certification programs, sitting above the entry-level grades and below the top grade that authorizes sole charge of a large or technically complex facility. It is intended for operators who already have substantial hands-on plant experience and are ready to take responsibility for process decisions rather than just performing assigned tasks. The Wastewater Treatment Operator Class III case studies are 5 cases and about 5,280 words.
1SVI 210 and Rising Blankets After a New Industrial Discharge
Your 4.5 MGD conventional activated sludge plant has two 0.75 MG aeration basins and two 70-ft secondary clarifiers. For three weeks the SVI has climbed from 115 to 210 mL/g; this morning's settleometer reads 610 mL/L with MLSS at 2,900 mg/L.
787 words, about 4 min2Two Primary Clarifiers Carrying a Three-Clarifier Flow
Your 4.2 MGD plant has three 60-ft-diameter primary clarifiers with 10 ft side water depth. One is drained for repainting, so the other two are carrying the full flow.
1,020 words, about 5 min3Sour Digester After Septage Acceptance Begins
Your 500,000-gallon primary anaerobic digester (95°F, 20-day HRT, 2,800 lb VSS/day) has run stably for a year, producing 12,000 ft³/day of 62% methane gas. Over eight days gas production has fallen to 6,200 ft³/day and the boiler can no longer hold temperature; the digester is at 92°F.
1,121 words, about 6 min4Chlorine Residual Present, Coliforms Still High
Your 4.0 MGD secondary plant disinfects with chlorine gas in a 125,000-gallon contact basin, giving about 35 minutes at peak flow. For three weeks fecal coliform results have been 300-600 CFU/100 mL against a 200 CFU/100 mL monthly geometric mean limit, even though the dose is high: 4.5 mg/L applied, 2.6 mg/L total residual at the outfall, and free residual only 0.05 mg/L.
1,176 words, about 6 min5Wet Well Blockage With a Deteriorating Atmosphere
a 30-inch interceptor is backed up at a 12-ft-deep pump station; sewage is at the rim of the wet well, and a resident reports sewage in a basement three blocks up. The blockage is a mat of wipes and grease at the wet well inlet.
1,176 words, about 6 min