wastewater grade 1 exam Treatment updated 20-24/2025

wastewater grade 1 exam Treatment updated 20-24/2025 domestic wastewater - CORRECT ANSWER-Comes from schools, homes, hospitals, businesses, light industrial facilities. population equivalents - CORRECT ANSWER-100 lbs wastewater per day, .2 lbs TSS/day, .17 BOD/day industrial wastewater - CORRECT ANSWER-Comes from industries. Compatible wastes can be processed by the plant. Incompatible wastes are toxic to the plant. sanitary wastewater - CORRECT ANSWER-The combined domestic and industrial waste waters from community. storm water - CORRECT ANSWER-Water that runs off roads, parking lots, and other impervious surfaces during rain and snow storms sanitary sewers - CORRECT ANSWER-Convey domestic and industrial waste waters, typically from where they are generated to the plant. storm sewers - CORRECT ANSWER-Convey storm water, typically from storm drains directly to a point of discharge (stream, river, ocean). combined sewers - CORRECT ANSWER-Convey sanitary waste water combined with storm water. Reasons to collect samples - CORRECT ANSWER-federal and state regulatory compliance, process control, trouble shooting, special studies including future designs. grab sample - CORRECT ANSWER-One time sample. Chlorine residual, coliform tests, settable solids, dissolved oxygen, pH, grease and oil, sulfide tests. Time based composite sample - CORRECT ANSWER-Fixed volume of sample is collected after passage of a set amount of time over a certain time period. Flow based composite sample - CORRECT ANSWER-Fixed volume of sample is collected after a prescribed amount of flow has passed through the sampling point, or a volume of sample proportional to the flow is collected after passage of a prescribed amount of time over a certain time period. This sample can also be called a flow proportional composite sample. diurnal flow - CORRECT ANSWER-Low at night between 2 and 5 am, steady steep increase in flow starting after 5 am, reaching first peak in the late morning or early afternoon, slight decrease through the afternoon, second peak between 6 and 9 pm, and a tapering off of to the low flows of 2 a