UTA6 Sewage Treatment & Disposal Flashcards
What term is used to describe wastewater that contains dissolved oxygen?
Aerobic
OR
Fresh
For proper storage, you should maintain the sample within what temperature range?
2°C to 10°C
For a wastewater plant that discharges effluent to a body of water, what type of permit must be obtained from the EPA or designated state agency?
NPDES
What is the minimum acceptable size of a septic tank, in gallons?
1,000
A heavy input of storm water into a sewage treatment plant results in what type of hydraulic problems?
Hydraulic overloading
Within a 24-hour period, the lowest flow in a sewage treatment system is between what hours?
0000 - 0500 hours
What is the normal color of wastewater containing dissolved oxygen?
Gray
Domestic sewage should have what noticeable odor?
Musty odor
What term is used to describe suspended solids that neither settle of float in wastewater?
Colloidal particles
Volatile solids either burn or evaporate within what temperature range?
500°C to 600°C
The acid or base properties of a water solution is measured in _______.
pH
What type of bacteria requires dissolved oxygen to remain alive?
Aerobic bacteria
A grab sample normally covers what time span, in minutes?
15 minutes
The flow proportional composite sample normally covers what time span, in hours?
24 hours
Treatment plant influent water should be between what pH values?
6.5 to 8 pH
An Imhoff cone should be used to perform which test?
Settleable solids test
When performing the BOD5 test, you should read one sample immediately and store the other at 20°C for exactly how many days?
5 days
Which test should be performed within 30 minutes of taking a sample?
Chlorine residual
After a sample is chilled to 4°C, a fecal coliform test should be performed within how many hours?
6 hours
What is the cheapest operating effluent discharge method?
Continuous discharge method
What type of effluent discharge requires a place to store the effluent?
Intermittent
Vegetation around evaporation and percolation basins should not be allowed to exceed what maximum height, in inches?
10 inches max
6 inches minimum
Trees should not be allowed to grow within how many feet of wastewater lagoons?
500 feet
(150) meters
When a septic tank discharges into a leaching field greater than 500 feet in length, you should incorporate what component(s) into the system?
Dosing tank and siphon
Regardless of size, a septic tank should be inspected at what standard intervals, in months?
2 month intervals
What is the minimum distance in feet that a shallow well can be located from a septic tank?
100 feet
What is the minimum distance in feet that leaching cesspools can be located from each other?
20 feet
What inch diameter size of perforated pipe is used in leaching fields?
4 inch pipe
What is the maximum allowable length in feet of a leaching field lateral?
100 feet in length
When a leaching field becomes inoperable, you must consider what option?
Replace it with a new system
