1. Wastewater Treatment

2. Wastewater refers to water that has been used by people in some way
Includes sewage water, water from showers and sinks, and water used in manufacturing processes

4. Septic Systems
Often used in rural areas
Wastewater runs from the house to an underground septic tank
Inside the tank soils and oils separate from water
The clarified water runs downhill to a drain field of perforated pipes laid in gravel
Here, the wastewater is decomposed by microbes
Solid waste is later pumped out of the septic tank and taken to a landfill

6. Municipal Sewer Systems
In cities, sewer systems carry wastewater from homes and businesses to centralized treatment locations
In NYC, we have a combined sewer system, which means that wastewater from residences and businesses goes to the same pipe system as runoff water from streets
Heavy rains cause them to overflow and discharge raw sewage into the waterways

11. Go to wastewater website

15. Sewage Sludge
The resulting wet solution is dried and either put in a landfill, incinerated, or used as fertilizer (38-50%)
Each year, 6 million dry tons of sludge are generated in the US
If toxic bacteria and other pathogens are not present, sludge can fertilize land used for food crops or livestock
In 1993, the EPA established safety regulations for sludge used as fertilizer, but many people still this is an unsafe practice