1.  Inorganic solids may also be called?  

     a. Volatile solids b. Loss on ignition c. Nonvolatile solids d. Dissolved

2.  A stream has a flow of 1 mgd. Its oxygen content is 8 mg/l. The number of pounds of oxygen in the stream
     per day is closest to which value?

     a. 8 b. 60 c. 67 d. 1,200 e. 8,000

3.  A shock load is:

     a. A heavy blow b. A big load in a truck c. An unexpected strong waste d. An unexpected bump e. None of these

4.  Which one of the following terms does not refer to conditions of respiration?

     a. Aerobic b. Anaerobic c. Facultative d. Parasitic e. Facultative aerobic

5.  A sludge drying bed 60 ft x 90 ft is filled to a depth of 12 inches.  When the sludge is ready for removal, it is
     found that its volume has been reduced by 70 percent. How many cubic feet of dried sludge are there on the
     drying bed?

      a. 540 b. 1,010 c. 1,620 d. 2,420 e. 3,780

6.  Saprophytic bacteria obtain their food from?

     a. Dissolved iron b. Organic material c. Inorganic material d. Dissolved sulfur compounds

7.  A lateral sewer serving a number of residences usually has the minimum size of 8 inches in diameter. An 8
     inch sewer must be placed on a slope of at least 0.4 percent. Which of the following is most closely equal to
     that?

     a. 1/16 in/ft b. 1/8 in/ft c. 1/4 in/ft d. 1/2 in/ft

8.  A plant ran blowers for 24 hours at 5,000 cu ft/min. A CBOD removal of 90 percent was obtained with a 5
     mgd flow containing 12,000 lb/CBOD per day. How many cubic feet of air were required for each pound of
     CBOD removed?

     a. 667 b. 1,200 c. 595 d. 1,000

9.   A plant with a flow of 24 mgd has a clarifier size of 4 million gallons. What is the settling time?

     a. 6 hours b. 4 hours c. 1.66 hours d. 6 days

10.  During the daytime, algal growth in a lake generally causes an increase in:

      a. Water temperature b. Nitrate concentration c. Iron concentration d. Calcium concentration e. DO content

12.  The purpose of the baffle at the inlet of a primary settling tank is to:

       a. Deflect the wind b. Maintain the proper water level in the tank c. Cause the flow in the tank to be distributed as evenly as possible, thus helping to eliminate fast moving currents d. Hold the side walls of the tank at a fixed distance

13. The results of a 5 day CBOD test for composite samples of wastewater in a trickling filter plant are as
      follows:
           Raw wastewater = 300 mg/l
           Primary tank effluent = 200 mg/l
           Final tank = 60 mg/l
           What is the percentage reduction in the 5 day CBOD accomplished by the trickling filter and final tank
           only?

      a. 47 percent b. 65 percent c. 70 percent d. 80 percent e. 90 percent

14.  Composite samples for CBOD tests should be preserved by:

      a. 10 ml chloroform b. Refrigeration c. 10 ml nitric acid d. 10 ml formaldehyde

15.  Which of the following diseases is not considered to be water borne?

      a. Smallpox b. Typhoid c. Bacillary dysentery d. Cholera e. Paratyphoid types A and B

16.  If water is added to concentrated acid, instead of acid to water:

       a. Water will sink to the bottom immediately b. Dilution is faster c. The temperature goes down and the mixture tends to form ice d. Heat is generated and the mixture tends to splash acid e. There is no difference

17.  Water seal connections to wastewater pumps should not be connected directly to the city water supply
       because:

       a. City water often contains sand b. City water pressure is too high and may blow a seal c. Wastewater may be drawn back into the water system d. Dry seals work better e. All of the above

18.  Bulking sludge in the final clarifier of an activated sludge plant may result in:

       a. Septic activated sludge b. Plugged air diffusers c. Excessive discharge of SS d. Decrease detention time in the aeration tank

19.  A treatment plant serves a town of 5,700. It also receives an industrial waste with 969 lb of CBOD daily.
       What is the population equivalent (PE) load of the plant? (PE is 0.17 lb CBOD/day/person).

       a. 969 b. 5,700 c. 6,669 d. 8,218 e. 11,400

20.  Raw wastewater entering the plant has a CBOD of 300 mg/l, and the plant effluent has a CBOD of 30 mg/l.
       What is percent reduction of CBOD through the plant?

       a. 60% b. 80% c. 90% d. 98%

21.  Based on a design criteria of 100 persons/acre, the detention time in wastewater ponds is generally:

      a. 10 to 20 days b. 40 to 50 days c. 1 to 6 days d. 100 days or more

22.  The accepted English unit of expression for treatment plant flow rate is:

       a. Cubic feet per second b. Gallons per minute c. Millions of gallons per day d. Acre feet per day

23.  GPM is the accepted abbreviation for:

       a. Gallons per man b. Gallons per minute c. Grams per milliliter d. Gallons per mile

24.  The results of the settleable solids test on raw wastewater and primary effluent are most useful in:

       a. Indicating the amount of suspended solids removed by primary sedimentation b. Calculating the exact quantity of primary sludge to be pumped c. Calculating the efficiency of the primary clarifier d. None of the above, there is no longer any value in the test

25.  The results of settleability of the activated sludge in the aeration tank indicate that 90 percent of the volume
       is solids. This means that:

       a. No action is needed b. Excess solids should be removed c. The dissolved oxygen should be lowered d. More solids should be introduced before wasting sludge

26.  An extended aeration plant has an influent CBOD of 135 mg/l and a flow of 0.68 mgd. It is operating at 94
       percent removal efficiency. The amount of CBOD removed is:

       a. 8.1 mg/l b. 89 mg/l c. 115.2 mg/l d. 126.9 mg/l

        The amount of CBOD removed in pounds per day is:

        a. 314.21 lb/day b. 719.68 lb/day c. 653.27 lb/day d. 1,038 lb/day

27. The SS test was performed and the following results were obtained:
            Volume of sample:  50 ml
            Crucible weight:  21.6329 g
            Crucible plus dry solids:  21.6531 g
            Crucible plus ash:  21.6360 g
            Computer the weight percentage of solids that are volatile.

      a. 34.2% b. 40.4% c. 62.0% d. 84.7% e. 98.1%

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