HIC Sewage & Waste Disposal Systems 2 — Questions and Answers
Question 1: A health inspector finds a septic tank that has not been pumped in over 10 years. What is the PRIMARY concern?
- Odor complaints from neighbors
- Solids overflow into the drain field causing failure (Correct answer)
- Tank corrosion from accumulated gases
- Groundwater infiltration into the tank
Correct answer: Solids overflow into the drain field causing failure
Accumulated solids (sludge and scum) overflow into the drain field, clogging the soil and causing system failure and potential sewage surfacing.
Question 2: Which federal agency has primary regulatory authority over publicly owned treatment works (POTWs) under the Clean Water Act?
- CDC
- OSHA
- EPA (Correct answer)
- FDA
Correct answer: EPA
The Environmental Protection Agency (EPA) administers the Clean Water Act and regulates POTWs through the National Pollutant Discharge Elimination System (NPDES).
Question 3: What does a 'perc test' (percolation test) measure in site evaluation for a septic system?
- Depth to the seasonal high water table
- The rate at which soil absorbs water (Correct answer)
- Total dissolved solids in groundwater
- Soil pH and bacterial content
Correct answer: The rate at which soil absorbs water
A percolation test measures how quickly water is absorbed by soil, expressed in minutes per inch, to determine if the site can support a drain field.
Question 4: A grease trap at a restaurant is required primarily to prevent which problem in the sewer system?
- Excessive water flow velocity
- Fats, oils, and grease (FOG) buildup causing blockages (Correct answer)
- Chemical contamination from cleaning agents
- pH imbalance in wastewater
Correct answer: Fats, oils, and grease (FOG) buildup causing blockages
Grease traps capture fats, oils, and grease before they enter the sewer, preventing blockages and interference with wastewater treatment processes.
Question 5: The minimum horizontal distance between a septic tank and a potable water well is typically:
- 10 feet
- 25 feet
- 50 feet (Correct answer)
- 100 feet
Correct answer: 50 feet
Most state codes require a minimum of 50 feet between a septic tank and a potable water well to protect against contamination, though requirements vary by jurisdiction.
Question 6: What is the primary function of a distribution box (D-box) in a septic system?
- To provide secondary treatment of effluent
- To equally distribute effluent to multiple drain field laterals (Correct answer)
- To remove solids before they reach the tank
- To aerate wastewater before disposal
Correct answer: To equally distribute effluent to multiple drain field laterals
A distribution box evenly divides septic tank effluent among multiple drain field lateral lines to ensure uniform loading across the entire leach field.
Question 7: Which indicator organism is most commonly used to test for fecal contamination in wastewater effluent?
- Salmonella typhi
- Escherichia coli (E. coli) (Correct answer)
- Cryptosporidium parvum
- Hepatitis A virus
Correct answer: Escherichia coli (E. coli)
E. coli is used as a fecal indicator organism because it is present in high numbers in human waste and is easier and cheaper to detect than actual pathogens.
HIC Sewage & Waste Disposal Systems 2
A health inspector finds a septic tank that has not been pumped in over 10 years.
What is the PRIMARY concern?