Plumbing Level 4 Private Waste Disposal Systems
Exam Q’s and A’s
The three main categories of private waste disposal systems are soil absorptions systems,
closed systems, and - -Organic systems
-The liquid waste produced by soil absorption systems is called - -Effluent
-To allow solids to settle out, wastewater should remain in a septic tank for at least - -24
hours
-As waste decomposes in an organic system, it emits - -Carbon dioxide and water vapor
-Covered pits filled with sand and gravel to accept wastewater from roofs and basements
are considered - -Drywells
-Distribution pipes in a leach field should of a grade of 2-4 inches per - -100 feet
-Leach field drain pipes should be no closer to property lines than - -10 feet
-The minimum capacity for a septic tank is - -750 gallons
-The allowable daily rate of effluent discharge into a leach field is measured in - -Gallons
per square foot
-In colder climates, the depth of soil over the top of a septic tank should be at least - -2 feet
-New sewage should enter the septic tank no less than 15 inches below the - -Scum layer
-Lay distribution pipes in trenches on a bed of gravel or crushed stone with a depth of no
less than - -6 inches
-Distribution pipes are sometimes covered with nylon screen material to - -Prevent silt
from entering
-Before pumping out a tank, allow it to ventilate for - -Several days
-Sludge should be pumped out of a septic tank when the tank is - -One-third full
-
Exam Q’s and A’s
The three main categories of private waste disposal systems are soil absorptions systems,
closed systems, and - -Organic systems
-The liquid waste produced by soil absorption systems is called - -Effluent
-To allow solids to settle out, wastewater should remain in a septic tank for at least - -24
hours
-As waste decomposes in an organic system, it emits - -Carbon dioxide and water vapor
-Covered pits filled with sand and gravel to accept wastewater from roofs and basements
are considered - -Drywells
-Distribution pipes in a leach field should of a grade of 2-4 inches per - -100 feet
-Leach field drain pipes should be no closer to property lines than - -10 feet
-The minimum capacity for a septic tank is - -750 gallons
-The allowable daily rate of effluent discharge into a leach field is measured in - -Gallons
per square foot
-In colder climates, the depth of soil over the top of a septic tank should be at least - -2 feet
-New sewage should enter the septic tank no less than 15 inches below the - -Scum layer
-Lay distribution pipes in trenches on a bed of gravel or crushed stone with a depth of no
less than - -6 inches
-Distribution pipes are sometimes covered with nylon screen material to - -Prevent silt
from entering
-Before pumping out a tank, allow it to ventilate for - -Several days
-Sludge should be pumped out of a septic tank when the tank is - -One-third full
-
