CSD 315 CERTIFICATION EVALUATION 2026
COMPREHENSIVE QUESTIONS AND SOLUTIONS
▶ A common reason for wastewater system failure is __________..
Answer: hydraulic overloading (due to modernized tank usually)
▶ The value Q is. Answer: Quantity of Sewage (GPD)
▶ Some malfunctioning OSSF can be made to function properly with
minimal cost by implementing ______________.. Answer: water
conservation measures.
▶ In estimating water usage for a single-family dwelling, the number of
_________ in the home is a key indicator; however, _________ should
also be considered.. Answer: bedrooms, square footage
▶ List four water saving plumbing devices that can be used in a home..
Answer: low flow toilets, low flow shower head, low flow faucets, pressure
reducing valves
▶ Identify four water-saving habits homeowners should adopt. Answer:
don't leave water running, full laundry and dishwasher loads,
reduce/eliminate use of garbage disposals, not using toilet for trash
disposal
▶ Two wastewater tests commonly used to measure the strength of
sewage are the ________ test and the ________ test.. Answer: BOD, TSS
▶ The minimum water usage rate that should be used for planning an
OSSF for a new home with three bedrooms and 3000 square feet of interior
living area is _______ gallons/day.. Answer: 300
▶ Blockage in the home plumbing system is often caused by _______,
________, and _________.. Answer: oils, greases, and fats
▶ It is recommended that _____________ are not used because they
significantly increase the amount of suspended solids and organic matter
that is discharged to sewage disposal system.. Answer: garbage disposal
, ▶ Several samples were taken from a small washateria with seven new
water-conserving machines and sent to a lab for BOD analysis. The
average BOD was 406 mg/L. What would be the minimum expected BOD
(organic) loading in lbs./day?. Answer: 4.74 lbs/day
▶ Would a treatment plant capable of handling 1500 gallons per day of
wastewater with BOD as high as 280 mg/L be capable of handling
wastewater from the above washateria? What is the organic loading
capacity of this treatment plant?. Answer: 3.50 lbs/day
▶ What is the loading rate of a system with: Q= 550GPD, BOD= 350 mg/L,
Ph=8.4, TSS= 400 mg/L. Answer: 1.6 lbs/day
▶ The most commonly use primary treatment component in Texas for on-
site systems is the. Answer: septic tank
▶ Which of the following produces the highest quality effluent?. Answer:
city sewage treatment plant
▶ what is the purpose of the inlet baffle or T?. Answer: Reduce velocity
and disperse flow, vent the tank to the building plumbing
▶ The minimum distances a watertight sewage treatment tank should be
from a water-well and a property line are. Answer: 50 feet and 5 feet
respectively
▶ which of the following is true regarding septic tanks?. Answer: The must
have two- or three-compartments
▶ A septic tank serving a new five-bedroom home with 3800 sqft must
have a minimum capacity of. Answer: 1,250 gallons
▶ Of what materials may a septic tank be constructed?. Answer: steel
reinforced concrete
▶ The expected volume of wastewater (Q) in gal/day from an older (pre-
1990) three-bedroom mobile home would be. Answer: 300
COMPREHENSIVE QUESTIONS AND SOLUTIONS
▶ A common reason for wastewater system failure is __________..
Answer: hydraulic overloading (due to modernized tank usually)
▶ The value Q is. Answer: Quantity of Sewage (GPD)
▶ Some malfunctioning OSSF can be made to function properly with
minimal cost by implementing ______________.. Answer: water
conservation measures.
▶ In estimating water usage for a single-family dwelling, the number of
_________ in the home is a key indicator; however, _________ should
also be considered.. Answer: bedrooms, square footage
▶ List four water saving plumbing devices that can be used in a home..
Answer: low flow toilets, low flow shower head, low flow faucets, pressure
reducing valves
▶ Identify four water-saving habits homeowners should adopt. Answer:
don't leave water running, full laundry and dishwasher loads,
reduce/eliminate use of garbage disposals, not using toilet for trash
disposal
▶ Two wastewater tests commonly used to measure the strength of
sewage are the ________ test and the ________ test.. Answer: BOD, TSS
▶ The minimum water usage rate that should be used for planning an
OSSF for a new home with three bedrooms and 3000 square feet of interior
living area is _______ gallons/day.. Answer: 300
▶ Blockage in the home plumbing system is often caused by _______,
________, and _________.. Answer: oils, greases, and fats
▶ It is recommended that _____________ are not used because they
significantly increase the amount of suspended solids and organic matter
that is discharged to sewage disposal system.. Answer: garbage disposal
, ▶ Several samples were taken from a small washateria with seven new
water-conserving machines and sent to a lab for BOD analysis. The
average BOD was 406 mg/L. What would be the minimum expected BOD
(organic) loading in lbs./day?. Answer: 4.74 lbs/day
▶ Would a treatment plant capable of handling 1500 gallons per day of
wastewater with BOD as high as 280 mg/L be capable of handling
wastewater from the above washateria? What is the organic loading
capacity of this treatment plant?. Answer: 3.50 lbs/day
▶ What is the loading rate of a system with: Q= 550GPD, BOD= 350 mg/L,
Ph=8.4, TSS= 400 mg/L. Answer: 1.6 lbs/day
▶ The most commonly use primary treatment component in Texas for on-
site systems is the. Answer: septic tank
▶ Which of the following produces the highest quality effluent?. Answer:
city sewage treatment plant
▶ what is the purpose of the inlet baffle or T?. Answer: Reduce velocity
and disperse flow, vent the tank to the building plumbing
▶ The minimum distances a watertight sewage treatment tank should be
from a water-well and a property line are. Answer: 50 feet and 5 feet
respectively
▶ which of the following is true regarding septic tanks?. Answer: The must
have two- or three-compartments
▶ A septic tank serving a new five-bedroom home with 3800 sqft must
have a minimum capacity of. Answer: 1,250 gallons
▶ Of what materials may a septic tank be constructed?. Answer: steel
reinforced concrete
▶ The expected volume of wastewater (Q) in gal/day from an older (pre-
1990) three-bedroom mobile home would be. Answer: 300
