Presentation on theme: "Wastewater Reuse: International Regulations and Trends"— Presentation transcript:
1 Wastewater Reuse: International Regulations and Trends Mohamed F. DahabDepartment of Civil EngineeringUniversity of Nebraska-Lincoln, USAPresented at:Water Arabia 2011January 31-February 2, 2011Manama, Bahrain
2 What is Wastewater Reuse? TerminologyWater reuseThe beneficial use of treated wastewater for agriculture, industry, etc.Water reclamationReclamation involves all processes used to treat wastewater so that it can be beneficially reusedWater recyclingRecycling generally means reuse of wastewater back in the same cycle where it is generated.
3 What is Wastewater Reuse? Categories of Water ReuseIndirect ReuseReuse of wastewater within the context of natural water systems (rivers, aquifers, etc.). The ultimate indirect reuse is through the global hydrologic cycleOther terms: Indirect potable reuseDirect ReuseThe direct beneficial reuse of treated wastewater for agriculture, industry, etc.Direct potable reuse: the reuse of reclaimed water for potable uses
4 Driving Factors for Water Reuse Water AvailabilityWater ConsumptionWater Quality
5 Benefits of Water Reuse Important element of integrated water resources utilization and managementTreated effluent is used as a water resource for many possible beneficial purposesFor many Arab coastal cities, wastewater would not be discharged to the sea thus reducing pollution to the marine environment and not creating public health issues
6 REUSE and GLOBAL CLIMATE CHANGE Global climate change will cause significant disruptions in the world's natural hydrological cycles.These hydrological changes will have significant impacts on water quality and supply and how we manage water resources.Most affected areas in the world include the Middle East and North Africa (MENA) area.Increased acceptance and reliance on reclaimed water will play a key role in mitigating the impacts of global climate change.
7 GLOBAL CLIMATE CHANGE Changes in total precipitation Projected Patterns of Precipitation ChangesRelative changes in global precipitation (%) for the period (relative to ) for Dec. - Feb. (left) and Jun. - Aug. (right).Source: IPCC, 2007
8 Considerations for Water Reuse Planning The foundation of successful water reuse programs:Providing reliable treatment to meet water quality requirements and environmental regulations for the intended reuse.Protection of public health and the EnvironmentGaining public acceptance.Economic viability
9 Public Health and Water Quality Considerations Physical water quality considerationsTurbidity, color, etc.Chemical water quality considerationsChemical constituents including solids, metals, nitrogen, phosphorus, etc.Biological water quality considerationsPathogens including bacteria, helminths, virus, etc.Emerging water quality considerationsPharmaceuticals, hormonal products, personal care products, other EDC’s.
10 Water Reuse Design Criteria Water quality requirementsMonitoring requirementsTreatment process requirementsTreatment reliability requirementsOperational requirementsCross-connection control provisionsUse area controls
11 Regulatory Water Reuse Criteria International Guidelines (WHO Guidelines)Country Guidelines and Requirements (U.S):Federal Water Reuse RequirementsU.S. EPA guidelinesState agency requirements and guidelinesLocal (county and municipal) requirementsOther Guidelines
12 International (WHO) Guidelines The WHO Guidelines provide for an "integrated protective management framework for maximizing the public health benefits of wastewater, excreta and greywater use in agriculture and aquaculture."
13 International (WHO) Guidelines Health ComponentEstablishes risk level associated with each identified health hazardDefines a level of health protectionIdentifies health protection measuresImplementation ComponentEstablishes monitoring and assessment proceduresDefines institutional oversightRequires system documentationConfirmation by independent surveillance
15 Some US Water Reuse Criteria California Department of Health:Water RecyclingGroundwater Recharge“ …the water resources of the State (must) be put to beneficial use to the fullest extent of which they are capable, and that the waste or unreasonable use or unreasonable method of use of water be prevented, and that the conservation of such waters is to be exercised…”Reuse goal: 1,200 million cubic meters annually by 2010
16 California Nonpotable Urban Uses Criteria Type of reuseTreatment requiredTotal coliform limitsFlushing sanitary sewersSecondaryNone specifiedIrrigation of restricted access landscape areas, nursery stock, & sod farms; landscape impoundments; cooling water (no mist); nonstructural firefighting; soil compaction; etc.Secondary Disinfection23/100 mLRestricted recreational impoundmentsSecondary Disinfection2.2/100 mLIrrigation of open access landscape areas; nonrestricted recreational impoundments; toilet & urinal flushing; process water; decorative fountains; commercial laundries and car washes; structural fire fighting; etc.Secondary Coagulation, Filtration, and Disinfection
17 California Water Recycling Criteria Media Filtration5 gpm/sqft. maximum (2 gpm/sqft. for traveling bridge automatic backwash filters) 2 NTU average daily turbidity 5 NTU 95% of time in any 24-hour period10 NTU maximumCoagulation required unless secondary effluent 5 NTU or lessMembranes 0.2 NTU 95 % of time in any 24-hour period0.5 NTU maximum
18 California Water Recycling Criteria - Disinfected Tertiary Reclaimed Water CT 450 mg-min/L90 minutes modal contact time (minimum) or 5 logs virus removal 2.2 total coliform/100 mL (7-day median)No more than one sample 23 total coliform/100 mL in any 30-day period 240 total coliform/100 mL (maximum)
19 UV Disinfection Guidelines UV dose 140 mW•s/cm2Lamp output = 70 % of nominal (new) UV lamp output70 % transmittance through quartz sleevesWastewater transmittance 55 %Minimum of three UV banks in series
20 Treatment Reliability Standby power supplyAlarmsMultiple or standby unit processesEmergency storage/disposal provisionsProvisions for continuous disinfectionNon-design featuresQualified personnelMonitoringO & M program
21 Use Area Controls Confinement to authorized use area Minimization of public contactCross-connection controlSurveillance and monitoringPublic notificationEmployee trainingWorker protection
22 Examples of Reuse and Recycling Operations in the U.S. State of California, U.S.
23 LA County Sanitation Districts 10 Water Reclamation PlantsQuality of effluent varies from undisinfected secondary to coagulated, filtered, disinfected tertiary.Total Water Reclamation capacity = 332 million m3/yrRecycle approximately 35% of their 735 m3/yr wastewater flowCustomers pay between 30% to 100% of O&M cost ($3 to $10 / 100 m3)
24 Padre Dam Municipal Water District Santee Water Reclamation Facility; 8000 m3/dBiological nutrient removal processDenitrification filtersSeries of lakes“Classic” reuse
25 City of LA - Tillman WRP Reuse area = 37.5 Hectare Capacity = 90 million m3/yr of Reclaimed WaterJapanese GardensBalboa LakeWildlife ReserveSepulveda Basin IrrigationLos Angeles River
26 West Basin Water Recycling Plant Produces 5 different qualities of recycled waterTertiary for industrial & irrigationNitrified for cooling towersSoftened RO for ground water rechargePure RO for low pressure boiler feedUltra-pure RO for high-pressure boilerCapacity = 80 million m3/yrCustomers include refineries, Goodyear Blimp home, Toyota HQ, Home Depot Nat’l Training Center
27 Carson Regional Water Recycling Plant Capacity = 19,000 m3/d water recycling plantMicrofiltration, RO, and Nitrification systemsEffluent used as industrial process water at an oil refinery
28 IRWD* Michelson Reclamation Plant Reuse area = 125 HectareTrails = 18 kmPonds = 30 Hectares36 Tons of Nitrogen Removed from WatershedOperates year around* Irvine Ranch Water District
29 IRWD Landscape Reclaimed Water Uses Reclaimed Water StreetscapeSingle Family EstatesReclaimed Golf CourseReclaimed ParkReclaimed Landscape
30 IRWD Other Reclaimed Water Uses Reclaimed Use In Carpet ManufactureUnder StrawberriesSanitary Use in High Rise Buildings
31 Groundwater Recharge Groundwater Replenishment* Salt Water Intrusion Subsidence Control* Many projects throughout the U.S. (e.g. FL, AZ, CA, CO, etc.).
33 U.S. EPA’s Guidelines for Indirect Potable Reuse of Municipal Wastewater Type or ReuseTreatmentReclaimed water qualityGroundwater recharge by spreading into potable aquifersSite-specific Secondary and disinfection (minimum) May also need filtration and/or advanced wastewater treatmentSite-specific Meet drinking water standards after percolation through vadose zone.Groundwater recharge by injection into potable aquifersSecondary Filtration Disinfection Advanced wastewater treatmentIncludes, but not limited to, the following: pH = 6.5 to 8.5 < 2 NTU No detectable fecal coli/100 mL > 1 mg/L Cl residual Meet drinking water standardsAugmentation of surface supplies
34 Groundwater Recharge: Draft California Regulation Issued August 2, 2002Surface Spreading / Subsurface InjectionSpecifies Controls forPathogenic organismsNitrogen compoundsRegulated contaminants and physical characteristicsNonregulated contaminantsMaximum Average Recycled Water Contribution
35 Water Factory 21–Orange County WD Began operation in 197620 million m3/yrFlocculation, re-carbonation, multi-media filtration, RO, activated carbon, and disinfectionGroundwater injection to prevent seawater intrusion
36 Wastewater Reuse in the U.S. Metro Area Million m3/yrLos Angeles, CAPhoenix, AZAustin, TXDenver, COLas Vegas, NV
37 Other Examples of Reuse and Recycling Operations Singapore PUB “NeWater” ProjectSingapore; a small island in SE Asia, depends on heavily on imported water.The “NeWater” project was started to recycle and reuse wastewater – largely for industrial use.Currently, about 15% of the island demand is met using highly treated wastewaterWastewater is treated using biological treatment followed by Microfiltration, RO, and UV disinfection.Water is used mostly by industrial users (e.g. circuit manufacturing).
38 Department of Civil Engineering University of Nebraska-Lincoln, USA Wastewater Reuse: International Regulation and Trends Thank You for ListeningMohamed F. DahabDepartment of Civil EngineeringUniversity of Nebraska-Lincoln, USA