TCEQ Class D Water Operator License Exam - Q & A Destratification is the mixing of lake water by compressed air to prevent layers of different
... [Show More] __________ from developing. Temperature All PWS in Texas are required to use ________ as the final disinfectant. Chlorine T/F: Powdered activated carbon (PAC) is commonly used to treat iron and manganese. False (removes the tastes and odors usually caused by dead and decaying algae and vegetation) A restricted zone of ______ ft radius from the raw water intake must be established and recreational activities and trespassing shall be prohibited. 200 T/F: The Rio Grande River is the longest river in Texas, stretching 250 miles along the Mexico border. False (1250 miles) T/F: Filtration is the first step in the removal of suspended solids. False (Sedimentation) Surface water is usually low in ________ and ________. minerals / gases Chemical dosage, water temperature, pH, _______, and the characteristics of the raw water all have an effect on the coagulation process. Mixing The two pathogenic protozoans resistant to chlorination are: ________ and _________ giardia / cryptosporidium T/F: Bacteria, algae, and turbidity can be a problem in surface water as can be municipal, industrial and agricultural pollution. True T/F: Coagulation works by the bonding of negatively charged turbidity to positively charged chemical coagulants. True T/F: Turbidity can shelter bacteria from the disinfection process. True
_______ is the last treatment step before storage. Disinfection T/F: Treated water is stored at the plant in a tank called a clear well. True The process of separating floc from water by gravity is called: __________ Sedimentation Filtration is the last barrier between the public and _______ or ________. giardia / cryptosporidium T/F: If the media collects in the wash water troughs, the wash rate is too high. True T/F: A check valve located on the discharge side of a pump is an isolating valve that allows water to flow one direction only. False (it is a controlling valve) T/F: The total dynamic head a pump must overcome is the distance from the water level on the suction side of the pump to the top of the water level on the discharge side of the pump and includes any friction and head loss encountered. True Dead-end mains must be provided with ________ Flush valves T/F: Common cross connections include a garden hose connected to a potable water source and submerged in a stock tank, a home served by a city water supply and private well, and a chemical container connected to a potable water supply. True T/F: If a repaired main must be returned to service quickly, does with 50 mg/L for 30 minutes. False (500 mg/L) T/F: TCEQ requires at least 1 BacT sample for each 1000 ft of new main. True Pipe and fittings must not contain more than ____% lead or solder/flux containing more than ___% lead. 0.25%, 0.2% The _________ is TCEQ's first choice to be used for backflow prevention when health hazards are involved. air gap Service tap components usually include a tapping saddle, corporation stop, service line tubing, curb stop, and _______. Meter T/F: A distribution system without dead ends is called an open system False (looped system) An intruder-resistant fence with lockable gates must enclose the storage site. True T/F: Ground water supply systems serving more than 50 connections must have a -ground (total) storage capacity of 200 gallons per connection and -elevated storage capacity of 100 gallons per connection or -pressure tank capacity of 20 gallons per connection. True The system must maintain a minimum pressure of ____ psi under normal conditions and at least _____ psi during emergencies. 35 / 20 The primary advantage of elevated storage is that pressure is ___________ when supply pumps are off or electrical power is lost. Maintained Stored water can meet sudden demands such as fire, absorb pressure surges, provide detention/contact time for ________, and allow for expansion of the distribution system. Chlorination T/F: Methods of fighting corrosion include coatings, temperature adjustment, and cathodic protection. False (pH adjustment, Orthophosphates, Poly-pigs) T/F: The most common design for residential service is the positive replacement meter. False T/F: The curb stop connects the main service line and the corporation stop isolates the meter for repair or replacement False (The corporation stop connects to the city main and the curb stop is used to isolate the meter for repair) T/F: Close a fire hydrant slowly or a water log could occur. False To help safeguard against electrocution or machine injury, a safety program should have a ___________ policy. lockout / tagout [Show Less]