Rural Sewage Flashcards
What is the primary function of anaerobic bacteria in a septic tank?
Anaerobic bacteria break down sewage into sludge, scum, and effluent.
In what type of environment do anaerobic bacteria thrive?
Anaerobic bacteria thrive in warm, moist, dark environments devoid of fresh air.
What is the minimum recommended distance between the invert of the inlet and outlet in a septic tank?
The minimum recommended distance is 2 inches.
What is the minimum recommended cover for insulation in a septic tank?
The minimum recommended cover is 12 inches.
What is the minimum distance a septic tank should be from a building?
The minimum distance is 3 feet.
What procedures must be followed when entering a septic tank?
Entry must follow WCB procedures as it is considered a ‘confined space.’
What gases are produced during the septic process?
The septic process produces methane, hydrogen sulphide, and other gases.
What is another term for the septic process?
The septic process is also called ‘putrefaction.’
How often should a septic tank be pumped on average?
A septic tank should be pumped every 5 years on average.
What role does the scum layer play in a septic tank?
The scum layer aids in heat retention.
What should not be done to a septic tank after pumping?
The tank should never be cleaned after pumping; a sludge layer on walls and bottom will aid in startup.
By what percentage should the size of a septic tank be increased if using a garburator?
The size should be increased by 50% if using a garburator.
What is the minimum ratio of width to length to promote ‘quiescent’ flow in a septic tank?
The minimum ratio is 1:3, and the maximum is 2:3.
What is the minimum retention period for sewage treatment in a septic tank?
The minimum retention period is 24 hours.
What is the minimum amount of ‘freeboard’ required for the scum layer in a septic tank?
A minimum of 12 inches of ‘freeboard’ is required.
How far should a septic tank be located from a source of domestic water?
It should be located no closer than 50 feet from a source of domestic water.
What is the smallest tank allowed in BC?
The smallest tank allowed in BC is 750 gallons.
When is the best time to perform pumpouts on a septic tank?
Pumpouts are best done in spring to allow restart in warm months.
What is the minimum recommended slope on a 4” building sewer?
The minimum recommended slope is 1/8” per foot.
How should a septic tank be sized?
It should be sized by the number of bedrooms in a house or by the number of people in an assembly building.
What materials can be used to construct a septic tank?
Materials can be concrete, fiberglass, or plastic.
What is the purpose of an effluent filter at the outlet of a septic tank?
An effluent filter at the outlet ensures solids stay in the tank.
What is the maximum opening size allowed in an effluent filter?
The maximum opening size in an effluent filter is 1/8 inch.
What types of bacteria could be present in a septic tank?
Pathogenic (disease-bearing) bacteria could be present.
