Last Question of the Day- For first semester! 1. How do you get the waste out of wastewater o For Friday, please gather all Questions of the day to turn.

Last Question of the Day- For Last Question of the Day- For first semester!first semester!

1. How do you get the waste out of 1. How do you get the waste out of wastewaterwastewater

o For Friday, please gather all Questions For Friday, please gather all Questions of the day to turn in for extra credit on of the day to turn in for extra credit on Marking period 2.Marking period 2.

Municipal Water ManagementMunicipal Water Management

o In US most In US most municipal water municipal water supplies are supplies are treated treated

o Collected from Collected from water or water or reservoirreservoir

o TreatedTreated

o Treated water Treated water distributed to distributed to customerscustomers

o Sewer lines bring Sewer lines bring sewage to sewage to treatment planttreatment plant

o Sewage treated at Sewage treated at sewage treatment sewage treatment plantplant

Municipal Water ManagementMunicipal Water Management

Municipal Sewage TreatmentMunicipal Sewage Treatmento Primary treatmentPrimary treatment

• Removing suspended and floating particles by Removing suspended and floating particles by mechanical processes mechanical processes

o Secondary treatmentSecondary treatment• Treating wastewater biologically to decompose Treating wastewater biologically to decompose

suspended organic material; reduces BOD suspended organic material; reduces BOD

Municipal Sewage TreatmentMunicipal Sewage Treatment

o Tertiary treatmentTertiary treatment• Advanced wastewater treatment methods Advanced wastewater treatment methods

that are sometimes employed after primary that are sometimes employed after primary and secondary treatments and secondary treatments

• Reduce phosphorus and nitrogenReduce phosphorus and nitrogen

Sewage SludgeSewage Sludge

o Solids remaining after primary and Solids remaining after primary and secondary sewage treatment has been secondary sewage treatment has been completed completed

o DisposalDisposal• Anaerobic digestionAnaerobic digestion• Application to soil as fertilizerApplication to soil as fertilizer• IncinerationIncineration• Disposal in sanitary landfillDisposal in sanitary landfill• (Ocean dumping)(Ocean dumping)

Municipal Sewage TreatmentMunicipal Sewage Treatment

Individualized Septic SystemsIndividualized Septic Systems

o Sewage piped to septic tankSewage piped to septic tank• Particles settle to bottomParticles settle to bottom• Grease and oils form scummy layer at top Grease and oils form scummy layer at top

that is decomposed by bacteriathat is decomposed by bacteria• Wastewater flows into drain field through Wastewater flows into drain field through

network of small, perforated pipes set in network of small, perforated pipes set in trenches of gravel or crushed stonetrenches of gravel or crushed stone

• Bacteria decompose remaining organic materialBacteria decompose remaining organic material• Purified wastewater percolates into groundwater Purified wastewater percolates into groundwater

or evaporates from the soilor evaporates from the soil

Individual Septic System-Individual Septic System-Septic TankSeptic Tank

Individual Septic System-Individual Septic System-Drain FieldDrain Field