ONSITE TREATMENT

Question 1

It is buried, watertight receptacles designed and constructed to receive wastewater from the structure to be served.

Answer 1

Septic Tanks

Question 2

It separates solids from the liquid, provides limited digestion of organic matter, stores solids, allows the clarified liquid to discharge.

Answer 2

Septic Tanks

Question 3

What are the three products of septic tanks?

Answer 3

Scum
Sludge
Effluent

Question 4

It is called the “sinkable” solids (soil, grit, bones, unconsumed particles) settle to the bottom of the tank. Anaerobic bacteria works.

Answer 4

Sludge

Question 5

It is called the substances lighter than water (oil, grease, fats) float to the top.

Answer 5

Scum

Question 6

It is called the clarified wastewater left over after the scum has floated to the top and the sludge has settled to the bottom.

Answer 6

Effluent

Question 7

It flows through the septic tank outlet into the drain field.

Answer 7

Effluent

Question 8

It is one of the parameters of septic tanks that refers to the liquid volume in the clear space between the scum and sludge layers.

Answer 8

Effective Volume

Question 9

It is one of the parameters of septic tanks that refers to the time the water spends in the tank, on its way from inlet to outlet.

Answer 9

Retention Time

Question 10

It is one of the parameters of septic tanks that refers to the function of the effective volume and the daily household wastewater flowrate.

Answer 10

Retention Time

Question 11

What is the formula of retention time?

Answer 11

Retention Time (days) = Effective Volume (gal)/Flow Rate (gal/day)

Question 12

A common design rule is for a tank to provide a minimum retention time of at least ____ hours, during which one-half to two-thirds of the tank volume is taken up by sludge and scum.

Answer 12

24

Question 13

Under ordinary conditions (i.e., with routine maintenance pumping) a tank should be able to provide ___________ of retention time.

Answer 13

2 to 3 days

Question 14

It refers to an artificially created water bodies.

Answer 14

Constructed Wetlands

Question 15

It is typically a long, narrow trenches or channels to promote the occurrence of plug flow conditions.

Answer 15

Constructed Wetlands

Question 16

It is typically a 1-m deep basin which is sealed with clay or some other form of lining to prevent percolation into groundwater.

Answer 16

Constructed Wetlands

Question 17

It is filled with soil in which reeds are then planted.

Answer 17

Constructed Wetlands

Question 18

It can significantly remove BOD, TSS, nitrogen and phosphorus, as well as metals, trace organics and pathogens.

Answer 18

Constructed Wetlands

Question 19

What are the two main operational conditions of constructed wetlands?

Answer 19

Mosquito Control and Plant Harvesting

Question 20

It is a primary settling basin or an anaerobic reactor commonly precedes constructed wetlands for sewage treatment.

Answer 20

Septic Tank

Question 21

What are the two systems of constructed wetlands?

Answer 21

1. Free water surface systems with shallow water depths.
2. Subsurface flow systems with water flowing laterally through the sand or gravel.

Question 22

How many galloons per acre per day is considered for the maximum hydraulic design loading flow through rate on the artificial wetlands?

Answer 22

25000 galloons per acre per day.

Question 23

What is the range (in days) for the minimum recommended detention time for treatment in the artificial wetland system?

Answer 23

7-14 days (Note: Most desirable ang 14 days)

Question 24

What is the recommended depth of flow in the wetland system? What about the recommended optimum depth?

Answer 24

6-24 inches
9 inches

Question 25

What configuration for constructed wetlands is recommended to enhance treatment efficiency in the system with a length to width ratio of between 5 and 10 to 1.

Answer 25

Rectangular configuration

Question 26

________________ should be considered to prevent aging of the wetland. Harvesting or burning are two options available.

Answer 26

Detritus removal

Question 27

To provide the greatest potential for wildlife enhancement, about how many percent of the artificial wetland surface should be open water with a depth no greater than five feet?

Answer 27

25 to 35 percent

Question 28

The emergent vegetation should comprise about how many percent of the available surface area with a water depth of less than two feet deep?

Answer 28

65 to 75 percent

Question 29

It is with the addition of algal population.

Answer 29

Lagoons

Question 30

It is where oxygen is supplied by natural reaeration from the atmosphere and algal photosynthesis.

Answer 30

Lagoons

Question 31

It is where the degradation by bacteria releases carbon dioxide and nutrients used by algae.

Answer 31

Lagoons

Question 32

It is where higher life forms such as rotifers and protozoa primarily as polishers of the effluent.

Answer 32

Lagoons

Question 33

It is where the temperature has a significant effect on aerobic pond operation.

Answer 33

Lagoons

Question 34

What are the five major factors of lagoons?

Answer 34

Organic loading, pH, nutrients, sunlight, and degree of mixing

Question 35

The total organic loading for the total surface area shall not exceed to how many pounds of BOD5 per acre per day?

Answer 35

20 pounds

Question 36

For lagoons, the design average flow rate shall be used to determine the volume required to provide a minimum liquid retention of how many days?

Answer 36

180 days

Question 37

The minimum depth for lagoons must be ___ feet. The maximum normal liquid depth should not exceed ___ feet.

Answer 37

2,6

Question 38

Oxygen requirements generally will depend on the ___________, the ___________________ and the ______________________________ to be maintained.

Answer 38

BOD loading, degree of treatment, concentration of suspended solids

Question 39

Aeration equipment shall be capable of maintaining a minimum dissolved oxygen level of ___ mg/l in the ponds at all times.

Answer 39

2