knipp – ch. bay #6

septic tank
holds waste water (sewage) when it leaves the house
drain field
area where waste water goes after it leaves the septic tank
allows solids to settle to bottom
primary purpose of septic tank
scum layer
top layer in septic tank
sludge layer
bottom layer of septic tank
water layer
middle layer of septic tank
1) it smells
2) it contains harmful bacteria
3) it contains harmful solids and chemicals
why do we have a septic system?
traps harmful/smelly gases from coming back up into the house
what is the purpose of the P-trap?
how well the soil absorbs the water
What determines the size of your drain field?
sand
Which type of soil absorbs water the best – clay, dirt or sand?
gravity
What powers the movement of waste water in a normal drain field?
sewer main
the big pipe that connects sewer pipes from different houses – usually found under a street
lift station
moves the waste water uphill
screening out of big solids
first step in primary treatment at a sewage treatment plant
primary treatment
settling out of solids occurs in this treatment of sewage
secondary treatment
bacteria break down organic solids during this stage of sewage treatment
tertiary treatment
chlorine is added to waster water (sewage) to kill bacteria during this stage of sewage treatment
false – there needs to be oxygen in the water so that fish don’t die
T/F – The dissolved oxygen level should be low when the water leaves the sewage treatment plant.
true – if the level of nutrients (N & P) are too high, algal blooms can occur which will decrease the ammount of dissovled oxygen when they die and are consumed by bacteria
T/F – There should be low levels of nitrogen (N) and phosphorus (P) in the treated wastewater when it leaves the sewage treatment plant.
false – you don’t want the excess chlorine killing any useful bacteria in the environment where the treated wastewater is released
T/F – The level of chlorine should be high when the treated wastewater leaves the sewage treatment plant.