Waste Water Operator Certification Study Guide Grade 1 Midterm Exam 2025

What is the most common reason for a wastewater to contain intermittent large amounts of sand, gravel, and grit? - Correct Ans-storm events WasteWater Sources & Characteristics: Combined wastewater is defined as - Correct Ans-sanitary wastewater and stormwater runoff WasteWater Sources & Characteristics: In general, the solids content in wastewater is about - Correct Ans-0.1% WasteWater Sources & Characteristics: In general, what is the % of suspended solids in the total amount of solids - Correct Ans-30% WasteWater Sources & Characteristics: Generally, the % of dissolved solids in the amount of total solids is about - Correct Ans 70% WasteWater Sources & Characteristics: Which type of organisms would most probably be associated with poor treatment or young biomass - Correct Ans-amoebas WasteWater Sources & Characteristics: Which type of organisms would most probably be associated with very clear plant effluent. low BOD and low amounts of suspended solids - Correct Ans-stalked cilates Basic WasteWater Treatment: Aerobic bacteria will reproduce and live in an environment that contains only - Correct Ans-oxygen Basic WasteWater Treatment: Water Operator Water Operator Anaerobic bacteria will reproduce and live only in an environment that completely lacks - Correct Ans-free or dissolved oxygen Basic WasteWater Treatment: The biochemical oxygen demand (BOD) test usually has a specific time of - Correct Ans-5 days Basic WasteWater Treatment: An Imhoff cone measures - Correct Ans-volume of settleable solids Basic WasteWater Treatment: Septic conditions are caused by - Correct Ans-anaerobic bacteria Basic WasteWater Treatment: Scum is usually removed in the _____treatment stage - Correct Ans-primary Basic WasteWater Treatment: When domestic wastewater enters natural waters, what species deplete most of the oxygen - Correct Ans-aerobic bacteria Basic WasteWater Treatment: Once the oxygen is depleted in a natural body of water, which organisms take over? - Correct Ans-anaerobic Basic WasteWater Treatment: The major gas produces by anaerobic decomposition is - Correct Ans-methane Wastewater Treatment Facilities: Another name for promary treatment is - Correct Ans-sedimentation Wastewater Treatment Facilities: Digester gas is_______when mixed with air the the proper proportions - Correct Ans extremely explosive Wastewater Treatment Facilities: Water Operator Water Operator A pond that is used to treat raw wastewater is called - Correct Ans-a waste stabilization pond Wastewater Treatment Facilities: A pond that has an aerobic top layer and an anaerobic bottom layer is called - Correct Ans-a facultative pond Preliminary Treatment: What is the angle of the bars on a manually cleaned bar screen? - Correct Ans-30 degrees Preliminary Treatment: What is the angle of the bards on a mechanically cleaned bar screen - Correct Ans-45 60 degrees Preliminary Treatment: What is the ideal wastewater velocity in FPS through a screen channel? - Correct Ans 1.5ft/s Preliminary Treatment: What is the ideal wastewater velocity in FPS for grit removal in a grit chamber - Correct Ans-1.0 ft/s Preliminary Treatment: In general, what is the water content of screen material - Correct Ans-80% Preliminary Treatment: What is the wastewater velocity range in FPS for grit removal in a grit chamber? - Correct Ans-0.7 - 1.4 ft/s Racks, screens, comminutors and Grit removal: Which one of the following chemicals gives water its greatest capacity to neutralize acids? - Correct Ans-hydroxide Racks, screens, comminutors and Grit removal: The bar rack is used - Correct Ans-when the bar scree