Self-Test D-1.11 Trade Waste Systems

Complete Self-Test D-1.11 and check your answers.

1. Which classification of fixtures would generally not need to be drained to a trade waste system?
   1. Residential
   2. Commercial
   3. Industrial
   4. Institutional

    

2. What type of trade waste system is most commonly seen in a commercial setting?
   1. Clothes washer draining into a lint trap
   2. Toilet draining into a septic system
   3. Pot sink draining into a grease interceptor
   4. Basin draining into a septic tank

    

3. Complete the following statement: “The discharge draining into a grease interceptor should ______.”
   1. Be as cool as possible
   2. Be as soapy as possible
   3. Be as hot as possible
   4. Move as fast as possible

    

4. How often should a grease interceptor be emptied?
   1. Yearly
   2. Monthly
   3. Daily
   4. When approximately 25% full

    

5. Approximately how much space in a pot sink’s compartments is assumed to be taken up by pots and pans when sizing a grease interceptor?
   1. 10%
   2. 25%
   3. 40%
   4. 50%

    

6. As referenced in the 2007 BC Plumbing Code clauses, a 3-in. trap used in a trade waste system is assumed to be how many fixture units?
   1. 3
   2. 5
   3. 7
   4. 10

    

7. What should be the minimum size of vent used in the trade waste system referenced in the diagram from the 2007 BC Plumbing Code?
   1. 1.25 in.
   2. 1.5 in.
   3. 2 in.
   4. 3 in.

    

8. What is the principle by which an oil interceptor separates oil from drainage water?
   1. Venturi
   2. Conductivity
   3. Capillary action
   4. Flotation

    

9. What item inside an oil interceptor, when adjusted properly, allows oil to be drained off by gravity to a collection tank?
   1. Standpipe sleeve
   2. Float
   3. Inverted bell
   4. Baffle

    

10. Which one of the following pH ranges would generally not need to be adjusted for drainage to be allowed directly into a sanitary drainage system?
    1. 8 to 11
    2. 3 to 6.5
    3. 5.5 to 8.5
    4. 7.5 to 10.5

     

11. What is the minimum percentage of calcium carbonate (CaCO₃) content for limestone chips used in an acid neutralizer?
    1. 100%
    2. 90%
    3. 80%
    4. 70%

     

12. What is the name of the device found in a commercial pot sink that allows hot water to continually flow into a sink compartment without allowing it to spill over the flood level rim of the sink?
    1. Continuous waste
    2. Waste and overflow
    3. Standing waste
    4. Standpipe

     

13. What is installed either on the piping entering a grease interceptor or inside the interceptor near its inlet that slows the flow rate and reduces turbulence so that grease more easily separates from the water?
    1. Vent
    2. Strainer
    3. Escutcheon
    4. Flow control fitting

     

14. What type of grease interceptor has a mechanism that regularly skims the top layer of FOG into a separate collection chamber so that it can be disposed of on a daily basis without opening up the interceptor?
    1. Passive
    2. Aggressive
    3. Automatic
    4. Automatic mechanical

     

15. A three-compartment pot sink drains to a grease interceptor. Each compartment measures 15 in. by 15 in. by 10 in. If the drain-down time is one minute and 25% of the volume of the compartments is taken up by pots and pans, what is the minimum flow rate in USGPM and grease storage capacity in pounds for the grease interceptor?
    1. 7.3 USGPM and 14.6 pounds capacity
    2. 14.6 USGPM and 29.2 pounds capacity
    3. 21.9 USGPM and 43.8 pounds capacity
    4. 29.2 USGPM and 58.4 pounds capacity

     

Answer Key: Self-Test D-1.11 is on the next page.