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Combined Sewer Systems Vs Not
Deep Tunnel Projects
Chicago - 109 miles - 15.6 bl/galAtlanta - 12.5 miles - 177 ml/galMilwaukee - 19.4 miles - 521 ml/gal
Atlanta1995: The Upper Chattahoochee Riverkeeper files a federal lawsuit against Atlanta, charging that state environmental officials are incapable of making the city stop polluting the river.
1998: The city signs a consent decree with the federal and state environmental regulators and the Riverkeeper, agreeing to fix its sewers and stop polluting the Chattahoochee and South rivers.
2004: Three of four city voters approve a 1 percent sales tax to help pay for the infrastructure improvements.
***Nov. 10, 2008: Atlanta celebrates compliance with the 1998 consent decree
• $25 million Greenway Acquisition Program, under which nearly 24 miles of stream buffers in Atlanta and eight metro counties were bought to protect the waterways from development;
• Separation of 33 miles of combined sewers;
• Construction of CSO Tunnels
Groundwater Pollution
Waste Water TreatmentPrimary treatment 1. Physically removing solids, grease, & grit using grates and screens 2. Settling tanks remove suspended and floating solids, but little of the
dissolved materials. Alum added for clumping.3. 30% of BOD removed
Secondary treatment 1. Aeration Tanks promote growth of bacteria that break down the
dissolved organic wastes. 2. Living filters are also used that contain bacteria growing on sand or
plastic.3. Settling Tank or Clarification Tank4. 90% of BOD now removed Tertiary treatment 1. Chlorine, UV radiation, Ozone, chlorine are used to kill bacteria and
pathogens2. Chemical processes remove phosphorous, nitrogen, heavy metals,
and chlorine.3. Water may be rejuvenated with oxygen
Improving Water Quality
Municipal Sewage Treatment
Primary and Secondary Sewage Treatment
Waste-Water Treatment
What to do with removedWaste? - digester
Municipal Sewage Treatment
Effectiveness- shows concentrations of pollutant following treatment
Individual Septic System
Individual Septic Systems
Drain field
Individual Septic Systems
Living Bacterial Culture Inside Tank
Jonesboro• Amid the 4,000 acres of wetlands in Jonesboro, Ga., are graded pools used
to filter water. The water is pumped in from a treatment plant and flows into these ponds, which are filled with all kinds of thick vegetation, including cattails, native grasses and water lilies.
• There have been complaints from neighbors not about the odor but about something else entirely: frogs.
• From the wetlands, the water runs over a gate and into a reservoir, one of four that were built to store billions of gallons of water. Residents use about 26 million gallons of water a day and through this system, the county reclaims 10 million gallons of that.
•
• The price tag is also an advantage — it can be as little as half the cost of building a regular wastewater treatment plant.
• This idea probably won't work for bigger cities like Atlanta because it requires a lot of land. Still, it's attractive for smaller communities.
Drinking Water
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