Wastewater Operator Certification Study Guide Grade 1 Exam Questions With 100% Correct Answers | 2026/2027 | Graded A+

Wastewater Operator Certification Study Guide Grade 1 Exam Questions With 100% Correct Answers | 2026/2027 | Graded A+ Wastewater Sources & Characteristics: What is the most common reason for a wastewater to contain intermittent large amounts of sand, gravel, and grit? - answer-storm events WasteWater Sources & Characteristics: Combined wastewater is defined as - answer-sanitary wastewater and stormwater runoff WasteWater Sources & Characteristics: In general, the solids content in wastewater is about - answer-0.1% WasteWater Sources & Characteristics: In general, what is the % of suspended solids in the total amount of solids - answer-30% WasteWater Sources & Characteristics:Generally, the % of dissolved solids in the amount of total solids is about - answer-70% WasteWater Sources & Characteristics: Which type of organisms would most probably be associated with poor treatment or young biomass - answer-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 - answer-stalked cilates Basic WasteWater Treatment: Aerobic bacteria will reproduce and live in an environment that contains only - answer-oxygen Basic WasteWater Treatment: Anaerobic bacteria will reproduce and live only in an environment that completely lacks - answer-free or dissolved oxygen Basic WasteWater Treatment: The biochemical oxygen demand (BOD) test usually has a specific time of - answer-5 days Basic WasteWater Treatment:An Imhoff cone measures - answer-volume of settleable solids Basic WasteWater Treatment: Septic conditions are caused by - answer-anaerobic bacteria Basic WasteWater Treatment: Scum is usually removed in the _____treatment stage - answer-primary Basic WasteWater Treatment: When domestic wastewater enters natural waters, what species deplete most of the oxygen - answer-aerobic bacteria Basic WasteWater Treatment: Once the oxygen is depleted in a natural body of water, which organisms take over? - answeranaerobic Basic WasteWater Treatment: The major gas produces by anaerobic decomposition is - answer-methane Wastewater Treatment Facilities: Another name for promary treatment is - answer-sedimentationWastewater Treatment Facilities: Digester gas is_______when mixed with air the the proper proportions - answer-extremely explosive Wastewater Treatment Facilities: A pond that is used to treat raw wastewater is called - answer-a waste stabilization pond Wastewater Treatment Facilities: A pond that has an aerobic top layer and an anaerobic bottom layer is called - answer-a facultative pond Preliminary Treatment: What is the angle of the bars on a manually cleaned bar screen? - answer-30 degrees Preliminary Treatment: What is the angle of the bards on a mechanically cleaned bar screen - answer-45-60 degrees Preliminary Treatment: What is the ideal wastewater velocity in FPS through a screen channel? - answer-1.5ft/sPreliminary Treatment: What is the ideal wastewater velocity in FPS for grit removal in a grit chamber - answer-1.0 ft/s Preliminary Treatment: In general, what is the water content of screen material - answer-80% Preliminary Treatment: What is the wastewater velocity range in FPS for grit removal in a grit chamber? - answer-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? - answer-hydroxide Racks, screens, comminutors and Grit removal: The bar rack is used - answer-when the bar screen is out of service Primary Sedimentation: Typically, what is the average detention time for wastewater in a primary clarifier? - answer-2 hr Sedimentation and Flotation:Name one gas this irritates the "eyes" - answer-chlorine Primary Sedimentation: Activated sludge clarifiers accept material to be settled from - answer-an aeration tank Primary Sedimentation: According to CWA, secondary treatment is defines as a wastewater plant producing an effluent that has no more than____total suspended solids and no more than_____BOD5 - answer-30 mg/L, 30 mg/L Primary Sedimentation: The color of bio film on a rotating Biological Contactor would appear____under normal operating conditions - answer-gray Activated Sludge: