INTRODUCTION TO What Is Wastewater? WASTEWATER TREATMENT

INTRODUCTION TOWASTEWATER TREATMENTJustin Mechell, EITExtension Program SpecialistTexas AgriLife Extension ServiceWastewater infrastructureOverview Whatis wastewater? Why are we concerned about wastewater? The big picture. Goals for wastewater treatment are evolvingg How do we implement our infrastructure? Wastewater Treatment Processes – The endresult is based upon your design Existing systems need upgrades to meet newrequirements: onsite and centralized optionsHydrologic cycleOnsite WastewaterTreatment System All facilities servingpeople generatewastewater How to meet theseneeds in an economicalmanner? Options: terInputRunoffWater TableStreamGround WaterOn-siteOnClusteredCentralized collection andtreatmentSlow MovingImpermeable LayerWastewater constituents Organic matter – BiochemicalOxygen Demand – indicatorSolids – TSSFOG – Fats, Oil & GreaseNutrients – lsMetalsPublic health Wastewater can contain disease causing Pathogens BacteriaVirusesParasitesProtozoaAscaris lumbricoides(roundworm)Hepatitis A Virus1

Environmental protectionTreat contaminants before they reach surface water orgroundwater Nutrients Phosphorus Nitrogen Organic loading Bacteria - pathogens BOD5Permitting dispersal systems The BIG picture Inorder to be an effective, longlong-term sustainablepart of the wastewater infrastructure, onsite,cluster or centralized wastewater treatmentsystems must be properly sited,sited designed,designedinstalled, operated and maintained. We must have professionals who can providesystem management services Trained professionals for all scales ofinfrastructure: onsite, cluster, & centralized.Onsite wastewater treatment systemTypes: onsite, clustered, community/centralizedOn--site wastewater treatment systemOn Usually limited by maximum gallons per day (5,000 gpd)gpd) TCEQ guidance: 30 TAC, Chapter 285 Prescriptive rules – local permitting, health departmentsIdentified as : public – septic system; TCEQ – onon--site sewage facilities (OSSF); nationally - OnOn-sitewastewater treatment system, (OWTS) Community systems (greater than 5000 gpd)gpd) Performance based – State level permitting TCEQ guidance: 30 TAC chapter 217Potential groundwater impact due to water quality and moundingDetailed soil analysisLocation of water wells within ½ mileUniformity of effluent distributionCentralized treatment systemMalfunctioning onsite systemBiosolids Land Application ProgramUniv of Nebraska Extension in Lancaster 05.jpg2

Malfunctioning centralized systemMalfunction Malfunctioningsystem – A wastewatertreatment system that is causing a nuisance oris not performing its intended function.Nuisance sewage, human excreta, or other organic wastedischarged or exposed in a manner that makes it apotential instrument or medium in the transmission ofdisease to or between personsan overflow from a septic tank or similar device,deviceincluding surface discharge from or groundwatercontamination by a component of an onon-site sewagefacility; ora blatant discharge from a wastewater treatmentsystem.Evolution of wastewatermanagementEvolution of wastewater treatmentgoalsOutdoor plumbing: the pit privy Goal: designated placeNo carrier needed toconvey waste Waste applied directly tothe soil Public health concernsaddressed Management: relocate Fromoutdoor plumbing to water reuse3

Indoor plumbing ConvenienceWater carrier to conveywaste out of facility‘Collection system’Public health andpathogensManagement: keep pipeflowingWhere does it go? OnsiteSewerOn--site disposalOn Goal: limit human contactKeep wastewater belowground Disposal options Public health Environment: groundwatercontamination Management: install, flushand forgetOff--site disposalOff Centralized sewer Collection piping fromhousesClusterCommunity TypeT peSeptic tank and soil treatment area Evolving goal: Disposal: effluent goes away versus treatmentDispersal: TREATMENTPublic health AND environmental issues addressedManagement: of sesewererGravityVacuum Small diameter STEP /STEG Treatment?“Disposing”Disposing of pathogensTreatment or dilution? Disposal: often no management at all;Dispersal: system management is critical Goal: TREATMENT AND DISPERSALWellAerobic soilGroundwaterOn--site system & hydrologic cycleOnOnsite WastewaterTreatment System Starting to address both environmental concerns inaddition to public health concerns Technological advancements now allow removal of: PathogensSolidsNutrients System management is vital to treatment Goal is now DISPERSAL WastewaterInputRunoffWater TableStreamGround WaterHydrologic cycleImpermeable Layer4

Off--site treatment and dispersalOffCentralized system & hydrologic cycle Convey wastewater tocentral point. Contaminants removed? PrimarySecondaryTertiary Treatment for removal ofspecific contaminants Discharge to surfacewater resourcesDurham County North Carolina WWTPWater reuse Goal: careful use of avaluable resource Wastewater vs. water Potable vs. nonnon--potableuses Landscape reuseToilet flushingTough to meet potablequalityManagement: O&M iseven more criticalEvolution of wastewater goals Outdoor plumbingIndoor plumbing - remove wastewater from the home.Disposal onon--site - prevent wastewater from surfacing inthe yard.Disposal offoff-site – prevent contact at facility and convey tostream.Treatment / dispersal onon--site - provide effective treatmentbefore effluent reaches surface or groundwater resources.Treatment / dispersal offoff--site – provide effective treatmentbefore discharging to stream.Reuse - reclaim the water.Varying rates of evolutionacross the country Driving forces for changeTMDL defined Vary Limited water resourcesE iEnvironmentalt l concerns TMDL program CZMP program Source water protection Watershed protection plansTMDL PSPS-LA NPSNPS-LA MOSTMDL Total maximum daily loadPS--LA Waste load allocation (PS)PSNPS--LA Load allocationNPS(Anthropogenic NPS Natural Sources)MOS Margin of safety(plus Margin for Growth?)5

Decentralized wastewater treatmentsystem:Changes in goals means: Approach must also changeSiting requirementsChoice of treatment components and systemsSystem O&MManagement programIndustry needs Publicacceptance of changewilling to pay for additional service, Enforcement on participants not willing tochange – public will to support enforcement Public Collection,treatment, and dispersal/reuse ofwastewater from individual homes, clusters ofhomes, isolated communities, industries, orinstitutional facilities,facilities at or near the point of wastegeneration. Onsite, cluster and centralized. Most cost effectivefor the site conditions.Decentralized approachDistributed management: Methodused to manage wastewaterinfrastructure where a responsible managemententity (RME) combines onsite, cluster andcentralized treatment in a cost effective andsustainable structure.What is an onsite wastewater treatmentsystem?Wastewater sourceCollection and storage3. Pretreatment components4. Final treatment and dispersal components Facility type 1. 2. DomesticCommercialIndustrialWastewater sourceUser Owner/familyEmployees6

Collection OptionsCollection Pipingfrom facilitywith cleanout BlackwaterGraywater Holding tanks Composting toiletsIncinerating toiletsFinal treatment and dispersalcomponentsPretreatment Total flowBlackwaterUrine separationW t streamWastetwithithmicrobial inhibitorsSeptic tanksAerobic treatment unitsMedia filtersConstructed wetlandsMembrane bioreactorsDisinfection How do we make the onon-sitewastewater treatment system work?What is a central sewer system? Same Evaluate the wastewatersource: hydraulic andorganic loading Evaluate sitecomponentsSourceCollectionPretreatmentAdvanced treatmentDisinfectionDispersal – mostlydischarge Responsiblemanagement entityTrench and beddistributionEvapotranspiration bedsLow pressuredistribution fieldDrip fieldSpray fieldDischarge Wastewater treatmentWastewater acceptance City of Cadillac, MichiganChoose a final treatmentand dispersal component Choose the appropriatepretreatment system Operation andMaintenance7

Roles with septic systemmanagement Site evaluation ntenanceMonitoringPumpingPoint of Sale InspectionSite evaluation Comprehensiveevaluation of soiland site conditionsfor a given landuse.Design Theprocess of selecting, sizing, locating,specifying and configuring treatment traincomponents that match site characteristicsandd ffacilityilit use as wellll as creatingti thethassociated written documentation. A design is also the written documentationof size, location, specification andconfiguration.Installation Theassembly andplacement ofcomponents of asystem,tincludingi l difinal grading andestablishment of anappropriate coverStartup Theprocess of settingoperational controls,verifying componentffunctionti andddocumenting initialoperating conditions ofa systemInspection Theevaluation ofand reporting onthe status of awastewatertreatment system8

Operation The action of assessingwhether each componentof the system isfunctioning properly Each component mustbe operational if thesystem as a whole is toachieve the desiredperformanceMaintenance The action of conductingrequired or routineplanned performancechecks, examinations,upkeep, cleaning, ormechanicalh i l adjustmentsdj ttto an onsite system. Includes Replacement ofpumps, filters, aeratorlines, valves or electricalcomponents.Monitoring Theaction ofverifyingperformance for apregulatoryauthority or amanufacturerPumping Theaction ofremoving septagefrom a wastewatertreatment systemcomponentPoint of sale inspectionRepair Inspect the treatmentsystem at the time ofproperty sale. Chance to upgrade thewastewater treatmentsystem if needed. Must have trainedprofessionals. No licensing in Texas forthis person. Isthe action of fixing substandard or damagedcomponents. Required repairsRecommended repairsUpgrades9

What quality do you desire?Why perform operation and maintenance? Keep systemsfunctioning properlyMaintain effluent qualityEarly detection ofproblemsPublic HealthEnvironmental ProtectionPublic safetySystem ReliabilityCustomer Satisfaction Primary treatmentGross solids removal Secondary treatmentBOD & TSS Disinfection Pathogen removal Tertiary treatmentNitrogen andphosphorous removalKing County Washington, VashonPrimary treatment componentsSecondary treatment components Soil Septictank Bar screen Primary clarifier Aeration– aerobictreatment Secondaryclarifier Sludge return toaeration MembranebioreactorsDisinfection methods Soil Dilution Chlorine Ultraviolet OzoneTertiary treatment components SoilLight& plantsremoval Nitrogen Denitrification Phosphorous removalChemical additionPrecipitation10

Summary Wastewatermanagement will play a vital rolein our future infrastructure needs. Technologies are available for removing theconstituentstitt off concern. Environmental regulations will continue to bemore stringent. Environmental health is ultimate form ofpublic health protection.Summary Asite evaluation is critical to determining thepotential for a site to treat wastewater. Advanced pretreatment and final treatmentand dispersal technologies are available formost situations. Select the most appropriate technology andscale of system for your site. Operation and maintenance is critical forlong--term functionlong11

a blatant discharge from a wastewater treatment system. Evolution of wastewater management Evolution of wastewater treatment goals From outdoor plumbing to water reuse Outdoor plumbing: the pit privy Goal: designated place No carrier needed to convey waste WasteapplieddirectlytoWaste applied directly to the soil Public health concerns