Water Advisory Board. May 10, 2016

Transcription

1 Water Advisory Board May 10, 2016

2 Background on potable reuse implementation and technology

3 Indirect potable reuse (IPR) Other Water Sources Environmental Buffer Water Treatment Drinking Water Wastewater Treatment (often with some advanced treatment) Customers

4 Direct potable reuse (DPR) Other Water Sources X Advanced Water Treatment Water Treatment Drinking Water Wastewater Treatment (often with some advanced treatment) Customers

5 Texas is leader in DPR implementation In planning In operation CRMWD at Big Spring (in operation) Wichita Falls (emergency projectoperated July July 2015) El Paso - pilot study completed. Planned operation 2019

6 CRMWD raw water production facility To Odessa, Midland & Stanton Big Spring Water Treatment Plant Lake J.B. Thomas Big Spring Big Spring Wastewater Treatment Plant Beals Creek Blended into Raw Water Transmission System CRMWD Raw Water Production Facility RO Concentrate Red Draw Reservoir E.V. Spence Reservoir

7 CRMWD raw water production facility Began operation in May 2013

8 Wichita Falls emergency DPR project Used existing advanced treatment facility to treat effluent from WWTP Advanced treated water blended 50/50 with raw water from lakes Blended water treated at conventional WTP Pipeline from WWTP to WTP laid above ground

9 El Paso water utilities advanced purified water concept Reclaimed Water Roberto R. Bustamante WWTP with Additional Treatment 10 MGD Advanced Purified WTP 7.2 MGD Distribution System Reclaimed Water Customers Rio Bosque Wetland Park Concentrate disposal: Blend w/wwtp effluent = 1.8 MGD Outfall Riverside Irrigation Canal

10 Potable reuse advanced treatment technologies CRMWD Wichita Falls El Paso San Angelo Secondary wastewater treatment + sand filter Secondary wastewater treatment Secondary wastewater treatment Secondary wastewater treatment + nutrient removal & cloth filters Microfiltration Microfiltration Microfiltration or Ultrafiltration Ultrafiltration Reverse Osmosis Reverse Osmosis Reverse Osmosis Reverse Osmosis Ultraviolet disinfection and advanced oxidation Ultraviolet disinfection Ultraviolet disinfection and advanced oxidation Ultraviolet disinfection and advanced oxidation

11 Wastewater treatment Settling basins (called clarifiers) remove solids Biological treatment breaks down organic matter and removes nutrients Cloth filters remove additional solids and particulates

12 Ultrafiltration Membranes with holes that are smaller than 1/1000 th of the width of human hair! Removes many contaminants and provides pretreatment for reverse osmosis

13 Reverse osmosis Water is forced through membranes with holes ~100 times smaller than ultrafiltration Removes salt, minerals, microorganisms, chemicals and trace organic compounds (pharmaceuticals, personal care products)

14 Ultraviolet disinfection/advanced oxidation Provides additional disinfection barrier Breaks down any remaining organic compounds

15 Safety of potable reuse

16 When does wastewater become water?

17 Water is like the Earth s lifeblood

18 How do we know if water is healthy?

19 We can detect anything, anywhere (almost). But what does it mean?

20 Wisdom from Paracelsus All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy...the dose makes the poison. Paracelsus ( )

21 Water quality parameters of interest Microorganisms -Cryptosporidium -Giardia -Bacteria -Viruses Chemicals -Inorganic -Organic -Disinfection byproducts -Radionuclides Trace Organic Compounds -Pharmaceuticals -Personal Care Products -Other chemicals measured at very low levels

22 So if it is detected, what do the numbers mean?

23 Picture a drop of water 1 drop = 0.05 ml or L It takes 4,732 drops to fill up 1 cup.

24 Perspective on concentration measures Concentration Unit Example Concentrations 1 part per million of trace 1 drop organics in 13.2 gallons (ppm; or 1 mg/l) (pharmaceuticals and personal care products) in water are typically 1 part per billion 1 drop in 13,209 gallons measured (ppb; or 1 in ug/l) ng/l X 3 1 part per trillion (ppt; or 1 ng/l) 1 drop in 13.2 million gallons X 20

25 Lessons learned from research Compiled data from 20 sites throughout the U.S. Evaluated risk of endocrine disrupting compounds (EDCs) and pharmaceuticals in drinking water

26 Back to Paracelsus The dose makes the poison - an example Gemfibrozil (antilipidemic- cholesterol control) Acceptable Daily Intake Drinking Water Equivalent Level (ADI-DWEL): 45,000 ng/l Water Source Maximum Concentration* (ng/l) Number of 8 oz glasses per day to reach ADI-DWEL Raw Wastewater 4, Treated Wastewater 1, Drinking Water ,000

27 More perspectives on relative dose Maximum Estradiol Equivalent, ng/l Measure of estrogenicity

28 Bottom line for proposed DPR project Multiple-barrier process to separate water from pollutants Proven processes purify water to level that s safe to drink and meets or exceeds all federal & state drinking water standards Purified water continually tested w/ online sensors & monitored by TCEQ Purification process produces drinking water more pure than San Angelo s existing drinking water & most bottled waters Proposed treatment processes used successfully in Texas, United States and around the world.

29 Review of potable reuse feasibility evaluation

30 Background

31 Potable reuse options EV Spence Wastewater Reclaimed Water WRF OH Ivie Potable DPR 3 TGCWCID #1 Twin Buttes Nasworthy Hickory 1 IPR IPR 2

32 Key evaluation issues Water quality Water rights/ Water supply yield Value of natural barriers Dissolved Solids (TDS, chloride, sulfate) Nutrients Pathogens Chemicals Trace organics Cost Schedule

33 Overview of evaluation process Initial Alternative Screening Based on evaluation of TDS and non-cost factors Detailed Treatment Evaluation Evaluation of multiple treatment options Develop life cycle costs Selection of Recommended Alternative Consider cost and non-cost factors

34 Screening level options considered Option Description Notes 1 2A 2B 2C IPR: Discharge to Twin Buttes IPR: Discharge to Lake Nasworthy RO of reclaimed water to manage TDS RO of reclaimed water to manage TDS Intake at Lone Wolf Reservoir (current intake location) RO of reclaimed water to manage TDS Intake at Lake Nasworthy RO of Lake Ivie water to manage TDS 3 DPR RO of 100% of reclaimed water

35 Final options evaluated in detail Option Description Notes 1 2A 2B 2C IPR: Discharge to Twin Buttes IPR: Discharge to Lake Nasworthy RO of reclaimed water to manage TDS RO of reclaimed water to manage TDS Intake at Lone Wolf Reservoir (current intake location) RO of reclaimed water to manage TDS Intake at Lake Nasworthy RO of Lake Ivie water to manage TDS 3 DPR RO of 100% of reclaimed water

36 Considerations for detailed treatment evaluation Protection of public health top priority Use TWDB DPR Resource Document as guidance Necessary water reclamation facility upgrades Impacts of water quality on membrane fouling/scaling Optimization of recovery from RO Implications for concentrate disposal Blending with other potable water supplies

37 Treatment options evaluated Trtmt Option Alternative Description WRF Improvement Options 1 DPR Convert to Biological Nutrient Removal and Add Membrane Bioreactor 2 IPR/DPR Convert to Biological Nutrient Removal 3 IPR/DPR Convert to Chemical Phosphorus Removal Advanced Water Treatment Options 1 DPR Reverse Osmosis->Ultraviolet Light/Advanced Oxidation Process 2 DPR Ultrafiltration->Reverse Osmosis->Ultraviolet Light/Advanced Oxidation Process 3 DPR Lime Softening->Ultrafiltration->Reverse Osmosis->Ultraviolet Light/Advanced Oxidation Process 4 IPR- diversion Lime Softening->Ultrafiltration->57% Reverse Osmosis and 43% Granular from Lone Wolf Activated Carbon 5 IPR- diversion Lime Softening->Ultrafiltration->29% Reverse Osmosis and 71% Granular from Nasworthy Activated Carbon

38 Final scenarios considered Scenario Alternative WRF Treatment Option AWT Treatment Option B 3 (DPR) BNR UF>RO>UV-AOP D 3 (DPR) BNR LS>UF>RO>UV-AOP F 2A (IPR) BNR LS>UF>57% RO/43% GAC H 2B (IPR) BNR LS>UF>29% RO/71% GAC

39 Alternative ranking process

40 Recommended alternative: DPR scenario D Drinking Water Customers Advanced Water Treatment Membrane Filtration (Ultrafiltration + Reverse Osmosis) Ultraviolet Irradiation + Advanced Oxidation Engineered Storage Concentrate Disposal Deep well injection Evaporation ponds Existing WTP Conventional Water Treatment Blend with other sources at existing WTP Existing WRF Enhanced Wastewater Treatment Biological Nutrient Removal Filtration Softening

41 Recommended alternative: opinion of probable cost Phase 1 Construction Cost (2015 $) Phase 2 Construction Cost (2015 $) Total Life Cycle Cost (NPW) Life Cycle Unit Cost ($/kgal) Initial Unit Cost (2015 $/kgal) $136,700,000 $16,600,000 $314,204,000 $1.87 $4.84 Notes: 1. Construction costs include engineering 2. Initial unit cost assumes a 30-year loan and interest rate of 3%

42 Pilot study is underway Biological nutrient removal basin Cloth media disk filter 4 parallel ultrafiltration membranes 3-stage reverse osmosis system Cloth Media Filter RO Membranes Parallel UF Pilot Unit (Dow/Toray) Evoqua Submerged UF Modules

43 Pilot study sampling points From Water Reclamation Facility Cloth Filter Pressure UF (x3) Reverse Osmosis Monitoring Point Submerged UF Concentrate Permeate Monitoring for all regulated drinking water contaminants & trace organic compounds

44 Water Advisory Board May 10, 2016