What Is The Water Quality That's Produced By A Sewage Treatment Plant
Sewage Treatment Plants are designed to treat wastewater from a property so that it can be disposed of without the risk of polluting local areas after discharge.
Wastewater Treatment Plants
Water is measured in three different ways as follows:
- BOD5
- Ammonia
- Suspended Solids
BOD5
How much organic material is in the water, the figure is given as mg/l (milligrams per litre).
BOD5 stands for Biological Oxygen Demand. Water contains oxygen and when organic material is put into water, bacteria breaks it down by using the oxygen up. By testing the water and seeing what the level of oxygen is over a period of time you can see how much organic material is in the water.
If there is no organic material in the water then this would mean there would be no loss of oxygen.
Or
If there is lots of organic matter the oxygen levels would drop.
From a Sewage Treatment Plant you are looking for a low BOD5 figure. In the UL a plant should be capable of producing water that has 20mg/l or lower.
Ammonia
Ammonia which comes from urine is poisonous to fish and plant life. Bacteria in the treatment plant breaks down the ammonia and converts it to nitrite. From a Sewage Treatment Plant, you are looking for an ammonia level of less than 20mg/l. On a larger treatment plant, and if the discharge is going to a specific site of interest the environment agency may ask for ammonia to be 5 or 10mg/l.
Suspended Solids
Suspended Solids (SS) or Total Suspended Solids (TSS) is a measure of fine particles that are suspended in the water after it has been treated. This should be less than 30mg/l.
