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INTRODUCTION TO INTRODUCTION TO WASTEWATER TREATMENT WASTEWATER TREATMENT

Justin Mechell, EITJustin Mechell, EIT

Extension Program SpecialistExtension Program Specialist

Texas AgriLife Extension ServiceTexas AgriLife Extension Service

OverviewOverviewWhat is wastewater?What is wastewater?

Why are we concerned about wastewater?Why are we concerned about wastewater?

The big picture.The big picture.

Goals for wastewater treatment are evolvingGoals for wastewater treatment are evolvinggg

How do we implement our infrastructure?How do we implement our infrastructure?

Wastewater Treatment Processes Wastewater Treatment Processes –– The end The end result is based upon your designresult is based upon your design

Existing systems need upgrades to meet new Existing systems need upgrades to meet new requirements: onsite and centralized optionsrequirements: onsite and centralized options

Wastewater infrastructureWastewater infrastructure All facilities serving All facilities serving

people generate people generate wastewaterwastewater

How to meet these How to meet these needs in an economicalneeds in an economicalneeds in an economical needs in an economical manner?manner?

Options:Options: OnOn--site site

ClusteredClustered

Centralized collection and Centralized collection and treatmenttreatment

Hydrologic Hydrologic cyclecycle

StreamWater Table

Onsite Wastewater Treatment System

WastewaterInput Runoff

Infiltration

Precipitation

Evapotranspiration

Impermeable Layer

Ground Water

Slow Moving

Wastewater constituentsWastewater constituents Organic matter Organic matter –– Biochemical Biochemical

Oxygen Demand Oxygen Demand –– indicatorindicator

Solids Solids –– TSSTSS

FOG FOG –– Fats, Oil & GreaseFats, Oil & Grease

Nutrients Nutrients –– Nitrogen, Nitrogen, Ph hPh hPhosphorousPhosphorous

PathogensPathogens

MedicationsMedications

ChemicalsChemicals

MetalsMetals

Public healthPublic health

Wastewater can contain disease causing PathogensWastewater can contain disease causing Pathogens BacteriaBacteria

VirusesViruses

ParasitesParasites

Ascaris lumbricoides

(roundworm)

ProtozoaProtozoa

Hepatitis A Virus

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Environmental Environmental protectionprotection

Treat contaminants before they reach surface water or Treat contaminants before they reach surface water or groundwatergroundwater NutrientsNutrients

•• PhosphorusPhosphorus

•• NitrogenNitrogen

Organic loadingOrganic loading•• BODBOD55

Bacteria Bacteria -- pathogenspathogens

The BIG pictureThe BIG picture

In order to be an effective, longIn order to be an effective, long--term sustainable term sustainable part of the wastewater infrastructure, onsite, part of the wastewater infrastructure, onsite, cluster or centralized wastewater treatment cluster or centralized wastewater treatment systems must be properly sited designedsystems must be properly sited designedsystems must be properly sited, designed, systems must be properly sited, designed, installed, operated and maintained. installed, operated and maintained.

We must have professionals who can provide We must have professionals who can provide system management servicessystem management services

Trained professionals for all scales of Trained professionals for all scales of infrastructure: onsite, cluster, & centralized.infrastructure: onsite, cluster, & centralized.

Permitting dispersal systemsPermitting dispersal systems Types: onsite, clustered, community/centralizedTypes: onsite, clustered, community/centralized OnOn--site wastewater treatment systemsite wastewater treatment system

Usually limited by maximum gallons per day (5,000 Usually limited by maximum gallons per day (5,000 gpdgpd))•• TCEQ guidance: 30 TAC, Chapter 285TCEQ guidance: 30 TAC, Chapter 285

Prescriptive rules Prescriptive rules –– local permitting, health departments local permitting, health departments Identified as :Identified as :Identified as : Identified as :

•• public public –– septic system; TCEQ septic system; TCEQ –– onon--site sewage facilities (OSSF); nationally site sewage facilities (OSSF); nationally -- OnOn--site site wastewater treatment system, (OWTS)wastewater treatment system, (OWTS)

Community systems (greater than 5000 Community systems (greater than 5000 gpdgpd)) Performance based Performance based –– State level permittingState level permitting

•• TCEQ guidance: 30 TAC chapter 217TCEQ guidance: 30 TAC chapter 217•• Potential groundwater impact due to water quality and moundingPotential groundwater impact due to water quality and mounding•• Detailed soil analysisDetailed soil analysis•• Location of water wells within ½ mileLocation of water wells within ½ mile•• Uniformity of effluent distributionUniformity of effluent distribution

Onsite wastewater treatment systemOnsite wastewater treatment system

Centralized treatment systemCentralized treatment system

Biosolids Land Application ProgramUniv of Nebraska Extension in Lancaster Countyhttp://lancaster.unl.edu/enviro/biosolids/sl05.jpg

Malfunctioning onsite systemMalfunctioning onsite system

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Malfunctioning centralized systemMalfunctioning centralized system MalfunctionMalfunction

Malfunctioning systemMalfunctioning system –– A wastewater A wastewater treatment system that is causing a nuisance or treatment system that is causing a nuisance or is not performing its intended function.is not performing its intended function.

NuisanceNuisance

sewage, human excreta, or other organic waste sewage, human excreta, or other organic waste discharged or exposed in a manner that makes it a discharged or exposed in a manner that makes it a potential instrument or medium in the transmission of potential instrument or medium in the transmission of disease to or between personsdisease to or between persons

an overflow from a septic tank or similar devicean overflow from a septic tank or similar device an overflow from a septic tank or similar device, an overflow from a septic tank or similar device, including surface discharge from or groundwater including surface discharge from or groundwater contamination by a component of an oncontamination by a component of an on--site sewage site sewage facility; or facility; or

a blatant discharge from a wastewater treatment a blatant discharge from a wastewater treatment system. system.

Evolution of wastewater Evolution of wastewater managementmanagementmanagementmanagement

Evolution of wastewater treatment Evolution of wastewater treatment goalsgoals

From outdoor plumbing to water reuseFrom outdoor plumbing to water reuse

Outdoor plumbing: the pit privyOutdoor plumbing: the pit privy

Goal: designated placeGoal: designated place

No carrier needed to No carrier needed to convey waste convey waste

Waste applied directly toWaste applied directly to Waste applied directly to Waste applied directly to the soil the soil

Public health concerns Public health concerns addressedaddressed

Management: relocateManagement: relocate

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Indoor plumbingIndoor plumbing Convenience Convenience

Water carrier to convey Water carrier to convey waste out of facilitywaste out of facility

‘Collection system’‘Collection system’

Public health andPublic health and Public health and Public health and pathogenspathogens

Management: keep pipe Management: keep pipe flowingflowing

Where does it go?Where does it go? OnsiteOnsite

SewerSewer

OnOn--site disposalsite disposal Goal: limit human contactGoal: limit human contact Keep wastewater below Keep wastewater below

ground ground Disposal optionsDisposal options Public health Public health

“Disposing” of pathogens“Disposing” of pathogens Disposing of pathogens Disposing of pathogens Treatment or dilution?Treatment or dilution?

Environment: groundwater Environment: groundwater contaminationcontamination

Management: install, flush Management: install, flush and forgetand forget

OffOff--site disposalsite disposal Centralized sewerCentralized sewer

Collection piping from Collection piping from houseshouses

Cluster Cluster

CommunityCommunity

T pe of se erT pe of se er Type of sewerType of sewer GravityGravity

Vacuum Vacuum

Small diameterSmall diameter

STEP /STEGSTEP /STEG

Treatment?Treatment?

Septic tank and soil treatment areaSeptic tank and soil treatment area Evolving goal: Evolving goal:

Disposal: effluent goes away versus treatmentDisposal: effluent goes away versus treatment

Dispersal: TREATMENTDispersal: TREATMENT

Public health AND environmental issues addressedPublic health AND environmental issues addressed

Management: Management: Disposal: often no management at all; Disposal: often no management at all;

Dispersal: system management is criticalDispersal: system management is critical

Groundwater

Well

Aerobic soil

Goal: TREATMENT AND DISPERSALGoal: TREATMENT AND DISPERSAL

Starting to address both environmental concerns in Starting to address both environmental concerns in addition to public health concernsaddition to public health concerns

Technological advancements now allow removal of:Technological advancements now allow removal of: Pathogens Pathogens SolidsSolids SolidsSolids NutrientsNutrients

System management is vital to treatmentSystem management is vital to treatment Goal is now DISPERSALGoal is now DISPERSAL

Hydrologic cycleHydrologic cycle

StreamWater Table

Onsite Wastewater Treatment System

WastewaterInput Runoff

OnOn--site system & hydrologic cyclesite system & hydrologic cycle

Impermeable Layer

Ground Water

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OffOff--site treatment and dispersalsite treatment and dispersal

Convey wastewater to Convey wastewater to central point.central point.

Contaminants removed?Contaminants removed? PrimaryPrimary

SecondarySecondary

TertiaryTertiary

Treatment for removal of Treatment for removal of specific contaminantsspecific contaminants

Discharge to surface Discharge to surface water resourceswater resources Durham County North Carolina WWTP

Centralized system & hydrologic cycleCentralized system & hydrologic cycle

Water reuseWater reuse

Goal: careful use of a Goal: careful use of a valuable resourcevaluable resource

Wastewater vs. waterWastewater vs. water

Potable vs. nonPotable vs. non--potablepotable Potable vs. nonPotable vs. non potable potable usesuses Landscape reuseLandscape reuse

Toilet flushingToilet flushing

Tough to meet potable Tough to meet potable qualityquality

Management: O&M is Management: O&M is even more criticaleven more critical

Evolution of wastewater goalsEvolution of wastewater goals Outdoor plumbingOutdoor plumbing Indoor plumbing Indoor plumbing -- remove wastewater from the home.remove wastewater from the home. Disposal onDisposal on--site site -- prevent wastewater from surfacing in prevent wastewater from surfacing in

the yard.the yard. Disposal offDisposal off--sitesite –– prevent contact at facility and convey toprevent contact at facility and convey to Disposal offDisposal off--site site –– prevent contact at facility and convey to prevent contact at facility and convey to

stream.stream. Treatment / dispersal onTreatment / dispersal on--site site -- provide effective treatment provide effective treatment

before effluent reaches surface or groundwater resources.before effluent reaches surface or groundwater resources. Treatment / dispersal offTreatment / dispersal off--site site –– provide effective treatment provide effective treatment

before discharging to stream.before discharging to stream. Reuse Reuse -- reclaim the water.reclaim the water.

Varying rates of evolutionVarying rates of evolution

Vary across the country Vary across the country

Driving forces for change Driving forces for change Limited water resourcesLimited water resources

E i t lE i t l Environmental concernsEnvironmental concerns•• TMDL programTMDL program

•• CZMP programCZMP program

•• Source water protectionSource water protection

Watershed protection plansWatershed protection plans

TMDL definedTMDL defined

TMDL = PSTMDL = PS--LA + NPSLA + NPS--LA + MOSLA + MOS

TMDLTMDL = Total maximum daily loadPSPS--LALA = Waste load allocation (PS)NPSNPS--LALA = Load allocation

(Anthropogenic NPS + Natural Sources)

MOSMOS = Margin of safety (plus Margin for Growth?)

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Changes in goals means:Changes in goals means: Approach must also changeApproach must also change

SitingSiting requirementsrequirements

Choice of treatment components and systemsChoice of treatment components and systems

System O&MSystem O&M

Management programManagement program

Industry needsIndustry needs

Public acceptance of changePublic acceptance of change

Public willing to pay for additional service, $$$Public willing to pay for additional service, $$$

Enforcement on participants not willing to Enforcement on participants not willing to change change –– public will to support enforcementpublic will to support enforcement

Decentralized wastewater treatment Decentralized wastewater treatment system:system:

Collection, treatment, and dispersal/reuse of Collection, treatment, and dispersal/reuse of wastewater from individual homes, clusters of wastewater from individual homes, clusters of homes, isolated communities, industries, or homes, isolated communities, industries, or institutional facilities at or near the point of wasteinstitutional facilities at or near the point of wasteinstitutional facilities, at or near the point of waste institutional facilities, at or near the point of waste generation.generation.

Onsite, cluster and centralized. Most cost effective Onsite, cluster and centralized. Most cost effective for the site conditions.for the site conditions.

Decentralized approachDecentralized approachDistributed management:Distributed management:

Method used to manage wastewater Method used to manage wastewater infrastructure where a responsible management infrastructure where a responsible management entity (RME) combines onsite, cluster and entity (RME) combines onsite, cluster and centralized treatment in a cost effective andcentralized treatment in a cost effective andcentralized treatment in a cost effective and centralized treatment in a cost effective and sustainable structure.sustainable structure.

What is an onsite wastewater treatment What is an onsite wastewater treatment system?system?

1.1. Wastewater sourceWastewater source

2.2. Collection and storageCollection and storage

3.3. Pretreatment componentsPretreatment components

4.4. Final treatment and dispersal componentsFinal treatment and dispersal components

Wastewater sourceWastewater source Facility typeFacility type DomesticDomestic

CommercialCommercial

IndustrialIndustrial

UserUser Owner/family Owner/family

EmployeesEmployees EmployeesEmployees

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CollectionCollection

Piping from facility Piping from facility with cleanoutwith cleanout BlackwaterBlackwater

GraywaterGraywater GraywaterGraywater

Collection OptionsCollection Options

Holding tanksHolding tanks Total flowTotal flow

BlackwaterBlackwater

Urine separationUrine separation

W t t ithW t t ith Waste stream with Waste stream with microbial inhibitorsmicrobial inhibitors

Composting toiletsComposting toilets

Incinerating toiletsIncinerating toilets

PretreatmentPretreatment

Septic tanksSeptic tanks

Aerobic treatment unitsAerobic treatment units

Media filtersMedia filters

Constructed wetlandsConstructed wetlands Constructed wetlandsConstructed wetlands

Membrane bioreactorsMembrane bioreactors

DisinfectionDisinfection

Final treatment and dispersal Final treatment and dispersal componentscomponents

Trench and bed Trench and bed distributiondistribution

Evapotranspiration bedsEvapotranspiration beds

Low pressureLow pressure Low pressure Low pressure distribution fielddistribution field

Drip fieldDrip field

Spray fieldSpray field

DischargeDischarge

What is a central sewer system?What is a central sewer system?

Same componentsSame components SourceSource

CollectionCollection

PretreatmentPretreatment PretreatmentPretreatment

Advanced treatmentAdvanced treatment

DisinfectionDisinfection

Dispersal Dispersal –– mostly mostly dischargedischarge

Responsible Responsible management entitymanagement entity

City of Cadillac, Michigan

How do we make the onHow do we make the on--site site wastewater treatment system work?wastewater treatment system work?

Evaluate the wastewater Evaluate the wastewater source: hydraulic and source: hydraulic and organic loadingorganic loading

Evaluate siteEvaluate site Wastewater treatmentWastewater treatment Wastewater treatmentWastewater treatment Wastewater acceptanceWastewater acceptance

Choose a final treatment Choose a final treatment and dispersal componentand dispersal component

Choose the appropriate Choose the appropriate pretreatment systempretreatment system

Operation and Operation and MaintenanceMaintenance

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Roles with septic system Roles with septic system managementmanagement

Site evaluationSite evaluation

DesignDesign

InstallationInstallation

StartupStartup

I tiI ti InspectionInspection

OperationOperation

MaintenanceMaintenance

MonitoringMonitoring

Pumping Pumping

Point of Sale InspectionPoint of Sale Inspection

Site evaluationSite evaluation

Comprehensive Comprehensive evaluation of soil evaluation of soil and site conditions and site conditions for a given land for a given land use.use.

DesignDesign

The process of selecting, sizing, locating, The process of selecting, sizing, locating, specifying and configuring treatment train specifying and configuring treatment train components that match site characteristics components that match site characteristics

d f ilit ll ti thd f ilit ll ti thand facility use as well as creating the and facility use as well as creating the associated written documentation. associated written documentation.

A design is also the written documentation A design is also the written documentation of size, location, specification and of size, location, specification and configuration.configuration.

InstallationInstallation

The assembly and The assembly and placement of placement of components of a components of a

t i l dit i l disystem, including system, including final grading and final grading and establishment of an establishment of an appropriate coverappropriate cover

StartupStartup

The process of setting The process of setting operational controls, operational controls, verifying component verifying component f ti df ti dfunction and function and documenting initial documenting initial operating conditions of operating conditions of a systema system

InspectionInspection

The evaluation of The evaluation of and reporting on and reporting on the status of athe status of athe status of a the status of a wastewater wastewater treatment systemtreatment system

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OperationOperation

The action of assessing The action of assessing whether whether eacheach component component of the system is of the system is functioning properlyfunctioning properly

Each component mustEach component must Each component must Each component must be operational if the be operational if the system as a whole is to system as a whole is to achieve the desired achieve the desired performanceperformance

MaintenanceMaintenance The action of conducting The action of conducting

required or routine required or routine planned performance planned performance checks, examinations, checks, examinations, upkeep, cleaning, or upkeep, cleaning, or

h i l dj t th i l dj t tmechanical adjustments mechanical adjustments to an onsite system.to an onsite system.

Includes Replacement of Includes Replacement of pumps, filters, aerator pumps, filters, aerator lines, valves or electrical lines, valves or electrical components.components.

MonitoringMonitoring

The action of The action of verifying verifying performance for a performance for a ppregulatory regulatory authority or a authority or a manufacturermanufacturer

PumpingPumping

The action of The action of removing septage removing septage from a wastewater from a wastewater treatment system treatment system componentcomponent

Point of sale inspectionPoint of sale inspection Inspect the treatment Inspect the treatment

system at the time of system at the time of property sale.property sale.

Chance to upgrade the Chance to upgrade the wastewater treatment wastewater treatment system if needed.system if needed.

Must have trained Must have trained professionals.professionals.

No licensing in Texas for No licensing in Texas for this person.this person.

RepairRepair

Is the action of Is the action of fixingfixing substandard or damaged substandard or damaged components.components. Required repairsRequired repairs

Recommended repairsRecommended repairs Recommended repairsRecommended repairs

UpgradesUpgrades

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Why perform operation and maintenance?Why perform operation and maintenance?

Keep systems Keep systems functioning properlyfunctioning properly

Maintain effluent qualityMaintain effluent quality Early detection of Early detection of

problems problems Public HealthPublic Health Environmental ProtectionEnvironmental Protection Public safety Public safety System ReliabilitySystem Reliability Customer SatisfactionCustomer Satisfaction

What quality do you desire?What quality do you desire? Primary treatmentPrimary treatment

Gross solids removalGross solids removal

Secondary treatmentSecondary treatment BOD & TSSBOD & TSSBOD & TSSBOD & TSS

DisinfectionDisinfection Pathogen removalPathogen removal

Tertiary treatmentTertiary treatment Nitrogen and Nitrogen and

phosphorous removalphosphorous removal

King County Washington, Vashon

Primary treatment componentsPrimary treatment components

Septic tankSeptic tank

Bar screenBar screen

Primary clarifierPrimary clarifier

Secondary treatment componentsSecondary treatment components SoilSoil

Aeration Aeration –– aerobic aerobic treatmenttreatment

Secondary Secondary clarifierclarifier

Sludge return to Sludge return to aerationaeration

Membrane Membrane bioreactorsbioreactors

Disinfection methodsDisinfection methods

SoilSoil

ChlorineChlorine

Ultraviolet LightUltraviolet Light

OzoneOzone

Tertiary treatment componentsTertiary treatment components

DilutionDilution

Soil & plantsSoil & plants

Nitrogen removalNitrogen removal DenitrificationDenitrification

Phosphorous removalPhosphorous removal Chemical additionChemical addition

PrecipitationPrecipitation

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SummarySummary

Wastewater management will play a vital role Wastewater management will play a vital role in our future infrastructure needs.in our future infrastructure needs.

Technologies are available for removing the Technologies are available for removing the tit t ftit t fconstituents of concern.constituents of concern.

Environmental regulations will continue to be Environmental regulations will continue to be more stringent.more stringent.

Environmental health is ultimate form of Environmental health is ultimate form of public health protection.public health protection.

SummarySummary

A site evaluation is critical to determining the A site evaluation is critical to determining the potential for a site to treat wastewater.potential for a site to treat wastewater.

Advanced pretreatment and final treatment Advanced pretreatment and final treatment and dispersal technologies are available forand dispersal technologies are available forand dispersal technologies are available for and dispersal technologies are available for most situations.most situations.

Select the most appropriate technology and Select the most appropriate technology and scale of system for your site.scale of system for your site.

Operation and maintenance is critical for Operation and maintenance is critical for longlong--term functionterm function