HOSMERIT
TCEQ WASTEWATER LICENSE EXAM QUESTIONS
AND 100% CORRECT ANSWERS
What is the sequence of steps in the Water Use Cycle? - ANSWER Environment --> Water
Treatment --> Water Distribution System --> Customer Use --> Wastewater Collection System
--> Wastewater Treatment --> Environment
What are the benefits to the collection system? - ANSWER - Control of health nuisances
- Eliminating odors and flies
- Cleanliness and aesthetics
- Comfort and convenience
Septic vs. Fresh wastewater? - ANSWER Septic wastewater doesn't contain dissolved oxygen
and is hard to treat. Fresh wastewater does contain dissolved oxygen and is easier to treat, yielding
higher quality effluent
Inflow - ANSWER Surface runoff that enters the collection system
Infiltration - ANSWER Groundwater that enters the collection system through holes, cracks,
etc.
What is the average domestic contribution to the collection system? Per person/day - ANSWER
100 gallons per day
What are the four wastewater characteristics? - ANSWER Physical, Chemical, Bacteriological,
and Radiological
,Domestic wastewater is % water and % solids - ANSWER 99.9% water, 0.1% solids
Settleable solids - ANSWER Suspended solids that will settle when wastewater flow is still or
slow moving
What is the range of the pH scale? -ANSWER 0 (most acidic) to 14 (most basic), 7 is neutral
Which of the following has the lower pH, septic or freshwater? Why? -ANSWER Septic has
lower pH because of volatile acids formed from wastewater decomposition
What is Hydrogen Sulfide (H2S)? When does it occur? - ANSWER Colorless, toxic, flammable
gas with the characteristic odour of rotten eggs. It is produced by the bacterial decomposition of
organic material in the absence of oxygen. It is heavier than air.
What is Methane? (CH4) What percentage of methane is in digester gas? - ANSWER A
colorless, odorless and highly flammable gas. Methane is an asphyxiant and lighter than air.
Digester gas contains 65% methane and is used for heating fuel or operating equipment.
What is carbon dioxide? (CO2) - ANSWER A colorless and odorless gas that has a smothering
effect. When inhaled in higher than normal concentrations, it can produce a sour taste in the
mouth and a stinging sensation in the nose and throat.
What is carbon monoxide? (CO) - ANSWER A colorless, odorless, and tasteless gas
Why is oil and grease a concern if present in wastewater? - ANSWER It can cause explosions,
fires, line blockages, and odor
, What are chlorides and why is excessive chlorides in wastewater bad? - ANSWER Excessive
chlorides interfere with treatment processes, especially trickling filters. They also can interfere
with laboratory tests.
What does the BOD test measure? - ANSWER It measures wastewater strength and the oxygen
depleting effect of wastewater effluent on the receiving stream. Specifically, it indicates the
amount of organic matter that can be oxidized by biological and chemical action in five days at
20 degrees Celsius.
What are pathogens? What are two viral diseases that could be carried in wastewater? -
ANSWER Polio and infectious hepatitis
What are precautions that can be taken by individuals in order to protect against pathogens in
the collection system? How do communities as a whole prevent waterborne disease? - ANSWER
- Wear cut-resistant gloves
- Wash after contacting wastewater
- Do not eat or smoke around wastewater
- Disinfect equipment with bleach
- Well-maintained water system
- Sanitary collection system
- Well-operated wastewater treatment plant
What is the purpose of wastewater treatment? - ANSWER - Dispose of solids
- Destroy pathogens
- Eliminate nuisances
- Protect downstream users
TCEQ WASTEWATER LICENSE EXAM QUESTIONS
AND 100% CORRECT ANSWERS
What is the sequence of steps in the Water Use Cycle? - ANSWER Environment --> Water
Treatment --> Water Distribution System --> Customer Use --> Wastewater Collection System
--> Wastewater Treatment --> Environment
What are the benefits to the collection system? - ANSWER - Control of health nuisances
- Eliminating odors and flies
- Cleanliness and aesthetics
- Comfort and convenience
Septic vs. Fresh wastewater? - ANSWER Septic wastewater doesn't contain dissolved oxygen
and is hard to treat. Fresh wastewater does contain dissolved oxygen and is easier to treat, yielding
higher quality effluent
Inflow - ANSWER Surface runoff that enters the collection system
Infiltration - ANSWER Groundwater that enters the collection system through holes, cracks,
etc.
What is the average domestic contribution to the collection system? Per person/day - ANSWER
100 gallons per day
What are the four wastewater characteristics? - ANSWER Physical, Chemical, Bacteriological,
and Radiological
,Domestic wastewater is % water and % solids - ANSWER 99.9% water, 0.1% solids
Settleable solids - ANSWER Suspended solids that will settle when wastewater flow is still or
slow moving
What is the range of the pH scale? -ANSWER 0 (most acidic) to 14 (most basic), 7 is neutral
Which of the following has the lower pH, septic or freshwater? Why? -ANSWER Septic has
lower pH because of volatile acids formed from wastewater decomposition
What is Hydrogen Sulfide (H2S)? When does it occur? - ANSWER Colorless, toxic, flammable
gas with the characteristic odour of rotten eggs. It is produced by the bacterial decomposition of
organic material in the absence of oxygen. It is heavier than air.
What is Methane? (CH4) What percentage of methane is in digester gas? - ANSWER A
colorless, odorless and highly flammable gas. Methane is an asphyxiant and lighter than air.
Digester gas contains 65% methane and is used for heating fuel or operating equipment.
What is carbon dioxide? (CO2) - ANSWER A colorless and odorless gas that has a smothering
effect. When inhaled in higher than normal concentrations, it can produce a sour taste in the
mouth and a stinging sensation in the nose and throat.
What is carbon monoxide? (CO) - ANSWER A colorless, odorless, and tasteless gas
Why is oil and grease a concern if present in wastewater? - ANSWER It can cause explosions,
fires, line blockages, and odor
, What are chlorides and why is excessive chlorides in wastewater bad? - ANSWER Excessive
chlorides interfere with treatment processes, especially trickling filters. They also can interfere
with laboratory tests.
What does the BOD test measure? - ANSWER It measures wastewater strength and the oxygen
depleting effect of wastewater effluent on the receiving stream. Specifically, it indicates the
amount of organic matter that can be oxidized by biological and chemical action in five days at
20 degrees Celsius.
What are pathogens? What are two viral diseases that could be carried in wastewater? -
ANSWER Polio and infectious hepatitis
What are precautions that can be taken by individuals in order to protect against pathogens in
the collection system? How do communities as a whole prevent waterborne disease? - ANSWER
- Wear cut-resistant gloves
- Wash after contacting wastewater
- Do not eat or smoke around wastewater
- Disinfect equipment with bleach
- Well-maintained water system
- Sanitary collection system
- Well-operated wastewater treatment plant
What is the purpose of wastewater treatment? - ANSWER - Dispose of solids
- Destroy pathogens
- Eliminate nuisances
- Protect downstream users
