Advancing Indirect Potable Reuse in Oklahoma Michael J. Graves Michael J. Watts, P.E., Ph.D.
Indirect Potable Reuse Drivers In Oklahoma, the period between January and March was the driest since 1921, including the 1930s Dust Bowl years The Wall Street Journal, 4/12/11, Ana Campoy
Any Relief In Sight?
Indirect Potable Reuse Drivers Stream studies (TMDLs) Improving stream quality Establish new permits Reducing PS loads Lower bacteria counts More stringent nutrient requirements POTWs forced to consider Advanced Treatment alternatives
Indirect Potable Reuse Drivers Wastewater Reuse
Reuse in Oklahoma HB 3055 Water for 2060 Act 1st in the Nation No more fresh water consumed in 2060 than is today
ODEQ Reuse Regulations Reuse Categories Category No. 1 Indirect Potable Reuse/ Aquifer Recharge. Category No. 2 Category No. 3 Application where there is a relatively high risk to human exposure such as residential irrigation. Application where there is lesser risk to human exposure such as irrigation of vineyards, restricted golf course irrigation Category No. 4 Low risk application such as pasture for non-dairy animals or sod farms.
ODEQ Reuse Regulations Reuse Categories Category No. 1 Indirect Potable Reuse/ Aquifer Recharge. Category No. 2 Category No. 3 Application where there is a relatively high risk to human exposure such as residential irrigation. Application where there is lesser risk to human exposure such as irrigation of vineyards, restricted golf course irrigation Category No. 4 Low risk application such as pasture for non-dairy animals or sod farms.
Stakeholder Workshops on IPR Municipal League Public University Sub Comm #1 Sub Comm #2 Industry Water Suppliers OWRB ODEQ
Indirect Water Reuse Subcommittee Technology Current treatment methods for producing high quality effluent are not recognized in the ODEQ construction standards Membranes Advanced Oxidation Etc.
Indirect Water Reuse Subcommittee Water Quality Standards Current WQS don t allow new point source discharges into a Sensitive Water Supply (SWS) SWS Public Water Supply Must demonstrate no impact
Implementation of Indirect Potable Reuse
What is the RISK? Indirect Potable Reuse Water Reclamation Facility Environmental Buffer Aquatic Cyanobacteria Cyanotoxins Bio accumulation of recalcitrant organics (plasticizers, flame retardants, etc.) Xeno androgens/xeno estrogens Potential System Impacts Antibiotic bacterial gene transfer Human
Water Reclamation Facility What is the RISK? Direct Potable Reuse Water Treatment Facility Potential System Impacts Aquatic Environmental Buffer Human National Research Council (2012) The risk from 24 selected chemical contaminants in the two potable reuse scenarios does not appear to exceed the risk in common existing water supplies. Robust, conservative engineering with multiple barriers for pathogens and anthropogenic organic pollutants
IPR remains most realistic scenario for potable reuse in most cases Most Significant Obstacle to DPR Public Acceptance / YUCK Factor Copyright 2007 by City Wire
If IPR is here to stay... A multi pronged approach is needed to protect against deterioration of freshwater resources Example: Pharmaceuticals and Personal Care Products (PPCP) Multiple point and non point sources in urban hydrosphere Buy in and participation of all watershed stakeholders needed to fully protect sensitive water supplies from impacts of waste indicator compound (e.g., PPCPs) accumulation
PPCPs: A Tangled Web... Sound Engineering + BMPs
Leachate as Source of PPCPs USGS Monitoring: IN Landfill 2000 2002 (Buszka et al. 2009) Waste Indicators Max Concentration ( g/l) Bisphenol a 1.3 Tributyl Phosphate 0.64 Ibuprofen 3.1 diethylphthalate 1.2
Impact of Pre-oxidation on PPCPs in Leachate Source: Feng and Watts 2013 Day 0 Day 5 Day 10-15 1 0.8 Control C/C0 0.6 t 1/2 0.4 0.2 50/50 Ozonated Leachate/Sludge Slurry 0 TCEP Control TCEP TBEP TBEP TCEP O TBEP O O 3 /H 2 O 3 3 2 Control O 3 /H 2 O 2 E2 Control E2 O 3 /H 2 O 2 E2 O 3
Advanced Septic Systems Domestic Wastewater Source: Anderson, Florida DOH 2012
Significant decrease in both EDC concentration and estrogenic activity Source: Stanford and Weinberg 2010
Impact of California Title 22 & Florida Reuse Regulations Gold standard for wastewater reclamation for IPR Activated Sludge Reverse Osmosis Microfiltration Membranes UV Advanced Oxidation
Impact of MF / RO / UV on PPCPs CASE Study: Orange County Water District (CA) 4000 3500 70 MGD of reclaimed wastewater for aquifer recharge 3000 Parts per trillion (ppt) 2500 2000 1500 1000 1000 800 600 400 200 Gemfibrozil DEET Oxybenzone UV Disinfection + Oxidation 0 Source: OCWD/Snyder
Schools of Thought on AOP The Role of Advanced Oxidation (with UV or O 3 ) in IPR 1. Can be used to provide oxidative barrier for priority pollutants that pass RO Nitrosamines (NDMA) Defined treatment goals for 70 90% oxidation 1,4 Dioxane (CA Title 22) 2. Enhanced Disinfection + conversion of recalcitrant organics to biodegradable organic carbon OH
EDC half-life in wastewater-influenced streams... Fourmile Creek t 1/2 > 30 days Boulder Creek t 1/2 ~ 10 days South Platte River t 1/2 ~ 15 days
Impact of Pre-oxidation on PPCPs in Leachate Source: Feng and Watts 2013 Day 0 Day 5 Day 10-15 1 0.8 Control C/C0 0.6 t 1/2 0.4 0.2 50/50 Ozonated Leachate/Sludge Slurry 0 TCEP Control TCEP TBEP TBEP TCEP O TBEP O O 3 /H 2 O 3 3 2 Control O 3 /H 2 O 2 E2 Control E2 O 3 /H 2 O 2 E2 O 3
The complete picture for water resource protection from PPCPs Sensitive Water Supply Advanced Water Reclamation Solid Waste Management Multi barrier Treatment
Questions mjgraves@garverusa.com mjwatts@garverusa.com