Florida DEP Indirect Potable & Direct Potable Reuse presentation 10 sep12
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Florida DEP Indirect Potable & Direct Potable Reuse presentation 10 sep12



This is a good presentation to better understand the rationale of using purified wastewater as a sustainable and saleable source of freshwater. It also describes the Business Case, two Case Studies ...

This is a good presentation to better understand the rationale of using purified wastewater as a sustainable and saleable source of freshwater. It also describes the Business Case, two Case Studies and the treatment technologies involved.



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Florida DEP Indirect Potable & Direct Potable Reuse presentation 10 sep12 Florida DEP Indirect Potable & Direct Potable Reuse presentation 10 sep12 Presentation Transcript

  • Terry Keep Florida DEP, September 2012 UV-Oxidation for Direct and Indirect Potable Reuse
  • Learning Objectives • IPR/DPR Drivers • IPR/DPR economics, business case • Public Perception/ the Language of IPR/DPR • History of IPR in California • Why UV Oxidation/Science of UV Oxidation • Case Studies: Orange County, CA (IPR) & Big Spring, TX (DPR)
  • • Water stress (CA, TX, NM, AZ, Australia, Israel, Singapore) • Environmental effects • Beach closures, coral reef degradation, • Water Body improvement: • Coastal: Tourism/beaches, Shell Fish Industry • Great Lakes: Algal Blooms, beaches, sport fishing IDP/DPR Drivers
  • UN Definition: Water stress occurs when the demand for water exceeds the available amount during a certain period or when poor quality restricts its use. Water stress causes deterioration of fresh water resources in terms of quantity (aquifer over-exploitation, dry rivers, etc.) and quality (eutrophication, organic matter pollution, saline intrusion, etc.) Source: UNEP Freshwater in Europe; glossary Some Stats: Canada and the U.S. are the two OECD countries that use the most water. • USA = 2000 m3/person/year • CANADA = 1600 m3/person/year • DENMARK = 200 m3/person/year (Least Consumptive OECD Country) WATER STRESS
  • Only about 0.5% of global water is “available” for consumption - all other water is sea-water or ice. WATER STRESS
  • • Growing demand on use of 0.5% of world’s water due to – Population growth, 80 MM people per year globally – Rapidly rising energy demands • Year 2000* – 30% of world’s total accessible fresh water was being used • Future (2025/2030)* – 70% of world’s total accessible fresh water will be used – 47% of world population in areas of water stress * Water, Energy and Security, EESI Congressional Briefing, Dr. Allan R. Hoffman, U.S. Department of Energy, 13 September 2006 WATER STRESS
  • California Some of the most populated regions of the state including Los Angeles and San Diego receive the bulk of their water from the Colorado river in the northern part of the state. Crosses St. Andreas fault • Extreme costs associated with transportation Texas Extreme heat and drought conditions causing strain on natural drinking water sources such as water tables and reservoirs WATER STRESS IN THE U.S.
  • • Reduce Growth • Conserve Existing Water Stores • Develop New Water Sources • Water Transfer • Desalination – Seawater – Brackish Water • Non-potable Reuse to Offset DW • Indirect or Direct Potable Reuse (IPR/DPR) WATER STRESS: WHAT ARE THE OPTIONS?
  • FINANCIALS IPR is cheaper than desalination and recycled non-potable water reuse • Desal: Higher energy costs • Purple Pipe: Installing new distribution system Fermian Business and Economic Institute, 2011
  • WATER SHORTAGE: WHAT ARE THE OPTIONS? 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 Desalination IPR Local Surface Water Water Transfer kWh/m3 IPR/DPR = 75% Less Energy than Desalination IPR/DPR is also less energy intensive than other water shortage solutions IPR is an Attractive Option Both in Terms of: 1. Costs 2. Energy Use 3. Security (not imported) City of San Diego report, 2011: IPR cost includes 10 mile pipeline to reservoir ENERGY
  • Indirect/Direct Potable Reuse: The Business Case The Business Cases: • Existing wastewater plant is a cost to municipality • Adding more technology & convert wastewater to a saleable product and reduce, if not eliminate, WWTPs operating costs 11
  • Indirect/Direct Potable Reuse: The Business Case The Business Cases: • IPR: Water is returned to aquifer: no new piping system needed = low infrastructure cost • DPR: Water is returned to distribution system or WTP = no cost pumping water into aquifer and pumping it out again. • Aquifer water quality lower than treated water 12
  • Indirect/Direct Potable Reuse: The Business Case • Drinking water quality affords flexibility in its usage (not just for golf courses, lawn watering) i.e. new building developments = increase tax revenue • Sustainable use of limited resource (new source of fresh water) • Lower impact on receiving waters and wildlife habitat 13
  • THE PRICE OF UV-OXIDATION When compared to microfiltration and RO, incorporating UV-oxidation can be considered a negligible additional expense both in terms of costs and energy use. 0% 20% 40% 60% 80% 100% IPR Energy Use EnergyUse(%ofTotal) UV-Oxidation Microfiltration Other Energy Use Reverse Osmosis 6.8%
  • WHAT’S INHIBITING ACCEPTANCE OF IPR/DPR? Negative public perception
  • Many people do not like the idea of their drinking water coming from treated wastewater even though in many parts of North America it is happening unintentionally • Great Lakes • Major Rivers (Mississippi, Ohio) The words used to describe IPR are often perceived as “unclean” and unattractive leading to negative opinions. • “Waste”water • “Re”cyled water and “Re”used water Greater acceptance for “purified” water DOES WORDING AFFECT OPINION? “purified”
  • PUBLIC SUPPORT FOR IPR INCREASES WITH EDUCATION San Diego County Water Authority: 2011 Public Opinion Poll Report, Rea & Parker 2011
  • WATER REUSE: WORLD PROGRESS • Israel reuses over 70% of its WW • Singapore reuses 15% with plans to double that by end of 2011 • Australia reuses 8%, has a national goal of 30% by 2015 • USA reuses 5-6% of WW for non-potable and potable purposed and this number continues to grow. Source: Guy Carpenter. WateReuse Association 2010
  • CALIFORNIA WATER REUSE REGULATIONS • The state of California is currently drafting the only law abiding regulations related to the application of non-potable reuse for drinking water augmentation in North America. • These regulations primarily monitor treated wastewater used for groundwater replenishment.
  • CALIFORNIA WATER REUSE REGULATIONS These regulations are part of the California Code of Regulations (CCR): Title 22 Division 4 – Environmental Health Chapter 3 – Recycling Criteria Article 5.1 – IPR for Groundwater Replenishment-Surface Applications Article 5.2 – IPR for Groundwater Replenishment – Subsurface Applications
  • U.S. WATER REUSE REGULATIONS - HISTORY 1978 • First groundwater replenishment regulations introduced to Title 22 in California • Regulations have been evolving for over 30 years • First groundwater regulations dealt with surface water spread 1989 • Regulations were re-done to incorporate direct groundwater injection
  • U.S. WATER REUSE REGULATIONS - HISTORY 2001-2002 • Regulations to total organic carbon (TOC) levels and organic treatment modified due to the emergence of NDMA and 1,4 Dioxane as contaminants of concern 2002-Present • Regulations continually being updated to reflect contaminants of emerging concern Present • Ground water recharge projects must incorporate advanced oxidation treatment after secondary wastewater treatment for direct groundwater injection projects
  • CCR TITLE 22 – KEY POINTS Advanced Oxidation (AO) Definition: Taking secondary treated wastewater and applying reverse osmosis (RO) and oxidative treatment processes for the further removal or microorganisms, total organic carbon (TOC), salts and other contaminant molecules This is a mandatory treatment step for groundwater replenishment projects which use direct groundwater injection. It is also highly recommended for groundwater replenishment projects through surface water spreading.
  • CCR TITLE 22 – KEY POINTS The Treatment Goals of Advanced Oxidation Include but are not Limited to: • < 10 ng/L NDMA • 0.5 log reduction of 1,4-Dioxane • <0.5 mg/L Total Organic Carbon • 99.5% rejection of salts Pathogen Removal (Groundwater Injection and Surface Water Spread) • 12 log enteric virus reduction • 10 log Giardia cyst reduction • 10 log Cryptosporidium oocyte reduction
  • REAL WORLD ADVANCED OXIDATION AO requires at least three different treatment processes (in addition to secondary wastewater treatment). Example: The Orange County Water District uses the following three treatment steps for groundwater injection. 1. Microfiltration 2. Reverse Osmosis 3. UV-Oxidation Microfiltration Removes 50% or organic material and effectively removes bacteria, protozoa, parasites and viruses Prevents downstream fouling of reverse osmosis membranes improving their functional lifetime
  • REAL WORLD ADVANCED OXIDATION Reverse Osmosis Removes molecules as small as 100 atomic mass units and 95% of organic contaminants. Required for advanced treatment according to Title 22 Removal portion of treatment train UV-Oxidation Provides an additional barrier for disinfection Removes molecular contaminants that escape microfiltration and RO through a combination of UV energy and oxidation. Destruction portion of treatment
  • WHY UV-OXIDATION It has been documented that molecules less than 100 atomic mass units in size and those with high hydrophobicity can pass through microfiltration and RO without being treated Contaminants with these characteristics include: NDMA 1,4-Dioxane Bisphenol-A Carbamazepine DEET Estradiol Ibuprofen Acetaminophen Clofibric acid Diclofenac Meprobamate Triclosan Oxybenzone
  • * Poussade, Y; A. Roux, T. Walker and V. Zavlanos. Advanced Oxidation for Indirect Potable Reuse – A Practical Application in Australia. Presented at OzWater 2009. NDMA – MEASURED POST RO AT BUNDAMBA*
  • THE ROLE OF UV-OXIDATION Molecules which elude filtration are eliminated by UV-oxidation through the combined action of two (2) independent degrading processes. 1. Direct UV-Photolysis 2. UV-Oxidation
  • O2 UV light is absorbed by the pollutant P: Degradation rate depends on: • Quantum yield of P, Φλ • Molar absorption coefficients of P in the UV range, ελ • Intensity and spectral distribution of the light source • Absorption of water background ProductsP hn (energy) [radical species] 1. DIRECT UV-PHOTOLYSIS
  • 1. DIRECT UV-PHOTOLYSIS Chemical bonds are broken by UV light
  • UV light is absorbed by hydrogen peroxide: Degradation rate depends on: • OH radical rate constant kOH,P • H2O2 concentration • Intensity and spectral distribution of the light source • Absorption of water background • OH radical water background demand Products H2O2 hn (energy) 2 •OH P + •OH kOH,P [radical species] O2 2. UV-OXIDATION
  • 2. UV-OXIDATION Hydrogen peroxide Hydroxyl radical Chemical bonds are broken by hydroxyl radicals
  • THE ROLE OF UV-OXIDATION Some contaminants that escape RO cannot be removed through oxidation and can only be eliminated through UV-light (photo-chemically labile) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 1,4-Dioxane NDMA Atrazine Geosmin UV-Photolysis/UV-OxidationContributiontoTotal ContaminantReduction(RelativetoAtrazine) UV + 10 ppm H2O2 Photolysis
  • THE ROLE OF UV-OXIDATION – FOCUS ON NDMA The EPA Integrated Risk Information System (IRIS) classifies NDMA as a class B2 (probable) human carcinogen • One in a million cancer risk = 0.7 ppt NDMA was one of the monitored contaminants from the Unregulated Contaminant Monitoring Rule 2 (EPA, 2006) • See Below EPA’s Third Regulatory Determination (expected in 2013) considering NDMA regulations. • Compliance would be expected 2015-1016 TOXOCOLOGY DATA
  • THE ROLE OF UV-OXIDATION – FOCUS ON NDMA NDMA PREVALENCE EPA evaluated nationwide NDMA between 2008-2010 25% of tested facilities had NDMA concentrations over 2 ppt • 1 in 1,000,000 cancer risk = 0.7 ppt • California Reporting Concentration = 10 ppt In Texas, 56% of 81 systems had NDMA concentrations above 2 ppt In California, 46% of 145 systems had NDMA concentrations above 2 ppt
  • THE ROLE OF UV-OXIDATION – FOCUS ON NDMA Due to NDMA’s resistance to chemical oxidation, alternate oxidation based treatment technologies are not as effective as UV-Oxidation (photo-chemically labile). Pisarenko, A.N., et al., 2011. In Press
  • NDMA – TREATED AT BUNDAMBA (RO Effluent) * Poussade, Y; A. Roux, T. Walker and V. Zavlanos. Advanced Oxidation for Indirect Potable Reuse – A Practical Application in Australia. Presented at OzWater 2009.
  • GWR INSTALLATION - ORANGE COUNTY, CALIFORNIA • 70 MGD (100 MGD peak) California facility treating wastewater to drinking water standards for groundwater replenishment • Water is injected (to protect from seawater) and percolated (to replenish) into the aquifer • MF/RO/UV-Oxidation treatment train (UV system uses monochromatic amalgam lamps) • System Expansion in progress Orange County’s Water Factory 21 pioneered the use of UV-oxidation.
  • NDMA FULL SCALE TESTING - ORANGE COUNTY, CA 0 10 20 30 40 50 60 70 80 1 2 3 4 5 6 7 Run # [NDMA],ppt [NDMA], Inf [NDMA], Eff 6 Reactors On Flow: >8.5 MGD 4 Reactors On
  • DISINFECTION TESTING - ORANGE COUNTY, CA Influent MS2 Effluent MS2 0.000 1.000 2.000 3.000 4.000 5.000 6.000 Log(pfu/mL)MS2
  • • 12.5 MGD California facility also treating wastewater to drinking water standards for groundwater replenishment • MF/RO/UV-Oxidation treatment train (UV system uses monochromatic amalgam lamps) • 1.3-log reduction of NDMA, disinfection GWR INSTALLATION – WEST BASIN MUNICIPAL WATER DISTRICT, CA West Basin Municipal Water District
  • NDMA FULL SCALE TESTING – WEST BASIN, CA 0 20 40 60 80 100 120 140 Influent NDMA Effluent NDMA NDMAConcentration (ng/L)
  • UV-Oxidation for Potable Reuse Case Study - Big Spring, Texas • Located approximately 300 miles west of Dallas • Population: 27,000 • Traditional Raw Water Sources: – E.V. Spence Reservoir (Surface Water) • Surrounding Cities/Towns: – Odessa – Stanton – Midland Big Spring
  • UV-Oxidation for Potable Reuse • Drinking water supply is managed by the Colorado River Municipal Water District (CRMWD) • In 2004, the CRMWD evaluated methods of augmenting or increasing drinking water availability to support growth and provide protection against the potential of supply shortages due to drought conditions. • Three approaches were considered: 1. Obtaining Raw Water from Other Groundwater and Surface Water Sources 2. Reusing Water for Non Potable Uses – Golf Course Irrigation, Agriculture 3. Reusing Water as Potable Water
  • UV-Oxidation for Potable Reuse Obtaining Raw Water from Alternative Sources: • Local groundwater supplies are limited and aquifers are not readily recharged • Other surface water sources were too far and would require extensive transportation • Other surface waters could suffer decreased availability due to drought conditions
  • UV-Oxidation for Potable Reuse SOLUTION – Potable Reuse (Direct Raw Water Blending) • CRMWD decided to build a single treatment plant that would treat secondary wastewater from surrounding communities to an “advanced” level • Known as the “Raw Water Production Facility” (RWPF) • The RWPF will generate “synthesized” raw water that will be added to the “natural” surface raw water of the E.V. Spence Reservoir • The synthesized raw water adds to the capacity of the reservoir and preserves its supply of source water to the drinking water treatment plants of Big Spring as well as the surrounding communities
  • UV-Oxidation for Potable Reuse Reusing Waste Water for Non Potable Reuse: • This approach would offset drinking water demand • Water users were widely dispersed which would require construction of an extensive distribution system • Demand was also very seasonal and did not provide a “year-round” solution
  • UV-Oxidation for Potable Reuse Big Spring Reclamation Project Source: Freese and Nicholls
  • UV-Oxidation for Potable Reuse RWPF Details • Advanced Treatment: MF/RO/UV-oxidation • UV-oxidation : – Treatment of NDMA and 1,4-Dioxane – Pharmaceuticals and endocrine-disrupting chemicals not removed by MF or RO – Additional disinfection barrier Raw Water Production Facility Design Parameters Design Flow: 1.8 MGD Target Contaminants: NDMA 1,4-Dioxane Design NDMA Reduction: 1.2 - Log Design 1,4-Dioxane: 0.5 - Log Oxidant: H2O2 Disinfection Method: UV Light
  • UV-Oxidation for Potable Reuse The Trojan Solution • Trojan Supplied two (2) TrojanUVPhox™ UV chambers along with an H2O2 dosing system for the new RWPF in Big Spring • Construction is currently in progress with commissioning expected in Spring 2013 Testimonial “The Trojan system offered a cost-effective additional layer of protection against a number of water quality concerns, with removal/inactivation mechanisms distinct from the membrane separation processes upstream” David Sloan – Senior Water Engineer
  • SUMMARY • State of California has been regulating IPR and groundwater recharge installations for over 30 years. • New regulations state that advanced treatment of wastewater required both RO and an oxidation treatment step. • Oxidation step removes molecules that are able to pass through RO membranes
  • SUMMARY • UV-Oxidation treats contaminants through both chemical oxidation and direct photolysis • UV-Oxidation (UV-photolysis) the only effective treatment against emerging contaminants of concern such as NDMA • After incorporating the required RO treatment and the highly recommended upstream microfiltration treatment, the additional costs associated with UV-Oxidation are minimal