Water Distribution Operator Class II case studies
Water Distribution Operator Class II · Put your knowledge to work in context.
The Water Distribution Operator Class II credential is a mid-level certification for people who operate and maintain public drinking water distribution systems - the pumps, mains, valves, hydrants, storage tanks, and service lines that move treated water from the plant to the customer's meter. It is typically pursued by distribution operators, maintenance and repair crews, and utility staff who already hold an entry-level certificate or have accumulated field experience, and who want to demonstrate competence at the level of independent system operation rather than supervised tasks. The Water Distribution Operator Class II case studies are 5 cases and about 2,704 words.
1Low Pressure at the End of the Line After a New Subdivision Ties In
A 12-inch transmission main fed by a 500 gpm booster station runs 2.1 miles to a pressure zone boundary. A new 140-lot subdivision was connected 900 feet upstream of the zone's dead-end, adding an estimated peak-hour demand of 210 gpm.
558 words, about 3 min2Total Coliform Positive After a Main Repair
A crew repaired a 10-inch ductile main break on a residential street, replacing a 4-foot section and a 6-inch service tee. The main was shut down, depressurized, and the trench was dewatered with a trash pump; the repair was made open-trench with the pipe ends exposed to the air for about 3 hours.
566 words, about 3 min3Pump Cycles Too Often After a Tank Level Setpoint Change
A 300,000-gallon elevated tank floats on a distribution zone served by two 250 gpm constant-speed booster pumps (one lead, one lag). To keep the tank fuller, an operator raised the pump-off level from 60% to 80% and left the pump-on level at 55%.
530 words, about 3 min4Backflow Incident at a Car Wash on a Dead-End Main
A car wash on a 2-inch service off a dead-end 8-inch main has a reduced-pressure-zone (RPZ) assembly. During a main break repair two blocks away, the main was shut down and the car wash lost pressure for about 2 hours.
506 words, about 3 min5Trench Cave-In Risk During a Main Replacement
A crew is replacing 300 feet of 8-inch main in a residential street. The trench is 5.5 feet deep, 3 feet wide, with near-vertical walls in damp, sandy-clay soil.
544 words, about 3 min