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WASTE WATER GRADE 1 NEWEST 2026/2027
ACTUALVERIFIED EXAM COMPLETE 100 QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+||NEWEST
EXAM!!!
What are the 7 apparent characteristics of hydrogen
sulfide (H2S) ? - ANSWER-1. Toxic: high concentration
kills
2. Flammable and explosive
3. Odor of rotten eggs
4. Quickly dulls one's sense of smell, giving one the false
impression that the gas has dissipated
5. Paralyzed one's ability to breathe
6. Corrosive especially to concrete
7. Heavier than air, collecting in below grade areas like
manholes, wet wells, dry wells, and other low lying areas
What is H2S a product of ? - ANSWER-Is a product of
anaerobic decomposition of organic matter
How much hydrogen sulfide is used in anaerobic digesters
wastewater plants and digester gas ? - ANSWER-It's in
parts per million parts (ppm) and is always less than 1%
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What is methane a product of ? - ANSWER-Methane is a
product of anaerobic decomposition
How much methane is in the gas produced by anaerobic
digesters ? - ANSWER-Average about 62%-70%
What does LEL stand for ? - ANSWER-Lower Explosive
Level
What is the LEL limit for methane ? - ANSWER-5%
What does UEL stand for ? - ANSWER-Upper Explosive
Limit
What is the UEL limit for methane ? - ANSWER-15%
What are explosive methane conditions ? - ANSWER-
When methane meets air. Between 5% methane / 95%air
and 15%methane / 85% air.
Other properties of methane ? - ANSWER-1. Flammable
and explosive
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2. Odorless
3. Not toxic but can cause asphyxiation
4. Lighter than air
What does Anaerobic Digesters Gas consist of ? -
ANSWER-65% methane
34% carbon dioxide
1% other gasses
What is CO2 (carbon dioxide)? - ANSWER-Aerobic
Bacteria
Anaerobic bacteria also produces what ? - ANSWER-CO2
Carbón Dioxide
4 Need to know's of Carbon Dioxide ? - ANSWER-1. Non-
flammable and non-explosive
2. Odorless
3. Not toxic but can cause asphyxiation
4. Heavier than air
How is pH measured ? - ANSWER-pH is measure with
with standard electrode that is typically calibrated using pH
buffers
WASTE WATER GRADE 1 NEWEST 2026/2027
ACTUALVERIFIED EXAM COMPLETE 100 QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+||NEWEST
EXAM!!!
What are the 7 apparent characteristics of hydrogen
sulfide (H2S) ? - ANSWER-1. Toxic: high concentration
kills
2. Flammable and explosive
3. Odor of rotten eggs
4. Quickly dulls one's sense of smell, giving one the false
impression that the gas has dissipated
5. Paralyzed one's ability to breathe
6. Corrosive especially to concrete
7. Heavier than air, collecting in below grade areas like
manholes, wet wells, dry wells, and other low lying areas
What is H2S a product of ? - ANSWER-Is a product of
anaerobic decomposition of organic matter
How much hydrogen sulfide is used in anaerobic digesters
wastewater plants and digester gas ? - ANSWER-It's in
parts per million parts (ppm) and is always less than 1%
,2|Page
What is methane a product of ? - ANSWER-Methane is a
product of anaerobic decomposition
How much methane is in the gas produced by anaerobic
digesters ? - ANSWER-Average about 62%-70%
What does LEL stand for ? - ANSWER-Lower Explosive
Level
What is the LEL limit for methane ? - ANSWER-5%
What does UEL stand for ? - ANSWER-Upper Explosive
Limit
What is the UEL limit for methane ? - ANSWER-15%
What are explosive methane conditions ? - ANSWER-
When methane meets air. Between 5% methane / 95%air
and 15%methane / 85% air.
Other properties of methane ? - ANSWER-1. Flammable
and explosive
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2. Odorless
3. Not toxic but can cause asphyxiation
4. Lighter than air
What does Anaerobic Digesters Gas consist of ? -
ANSWER-65% methane
34% carbon dioxide
1% other gasses
What is CO2 (carbon dioxide)? - ANSWER-Aerobic
Bacteria
Anaerobic bacteria also produces what ? - ANSWER-CO2
Carbón Dioxide
4 Need to know's of Carbon Dioxide ? - ANSWER-1. Non-
flammable and non-explosive
2. Odorless
3. Not toxic but can cause asphyxiation
4. Heavier than air
How is pH measured ? - ANSWER-pH is measure with
with standard electrode that is typically calibrated using pH
buffers
