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20 Cards in this Set
- Front
- Back
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If secondary chlorine is added to a distribution system that uses chloramines, the chlorine may be added to a desired chlorine to ammonia-nitrogen level of |
4.5:1 to 5.1 |
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media loss from a filter in any four-month period is considered to be excessive if the amount of loss is greater than |
5 cm. |
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How much more soluble is ozone in water than oxygen in water? |
20 times |
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A 1-ton cylinder filled with chlorine weighs approximately |
3,700 lb |
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How much will the alkalinity of the treated water increase for each mg/L of lime added? |
1.28 mg/L |
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Which method can be used to control scaling but is never used to control corrosion? |
Sequestering |
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Where can I smoke a joint deflection for full lengths of standard 48-inch ductile-iron push-joint pipe? |
3 degrees |
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Foot valves are a special type of |
Check valve |
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What type of pipe joint is most commonly used for river crossings? |
Ball-and-socket joint |
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Which type of relays are placed on each phase of a power supply to open a control circuit and stop a motor if the current becomes excessive? |
Thermal-overload relays |
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How many pounds per day of 65% calcium hypochlorite are required for maintaining a 2.5 mg/L dosage for a 2,575-gpm treatment plant? |
120 lb/ day |
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One of the disadvantages of using chloramines is that chloramines can induce |
Hemolytic anemia |
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Which of the following would most likely control foaming? |
Water sprays |
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Which method can be used to control scale and corrosion? |
pH and alkalinity adjustment with lime |
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When reduction occurs |
electrons are gained by the species being reduced |
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When one substance is dissolved in another and will not settle out, what is the product called? |
A solution |
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Which type of distribution system configuration has small demands that generally terminate as dead ends? |
Tree system |
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Which is the location of running annual average for total trihalomethanes and sum some of haloacetic acid under the Stage 2 Disinfectants and Disinfection By-Products Rule? |
80/60 ug/L |
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When a base reacts with an oxide of a nonmetal, it will produce |
a salt |
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Gravel displacement in a filter bed from backwash rates with velocity too high could eventually cause |
a sand boil |
