Indirect Potable Reuse:

One piece of the solutionOrange Water and Sewer Authority

Board Meeting July 9, 2015Presentation by Bonnie Nevel

The challenge… • Population growth in OWASA service

area

The challenge…

Source: RENCI (Renaissance Computing Institute), UNC-Charlotte

Source: Orange County 2030 Comprehensive Plan

Southern Orange County Future Land Use

The challenge…

Source: Jordan Lake Water Supply Round Four Allocation Request, draft 2014

Current capacity:10.5 mgd

The challenge… • Population growth in OWASA service

area– Orange County: 39% population increase by 2040– Projected 2060 water demand 3X current level– Greater pressure on watershed health

• Climate change, natural drought cycles• OWASA mission – high quality services– Responsible, sustainable, creative stewardship

…calls for multiple solutionsDemand reduction

– Tiered pricing, use restrictions, education/outreach

– Increased industrial and residential efficiency

Regional partnerships, expanded supply

Reclaimed water for non-potable uses– OWASA/UNC partnership, 11% of water demand

Reclaimed water for potable uses– Indirect potable reuse and direct potable reuse

…calls for multiple solutionsDemand reduction

– Tiered pricing, use restrictions, education/outreach

– Increased industrial and residential efficiency

Regional partnerships, expanded supply

Reclaimed water for non-potable uses– OWASA/UNC partnership, 11% of water demand

Reclaimed water for potable uses– Indirect potable reuse and direct potable reuse

…calls for multiple solutionsDemand reduction

– Tiered pricing, use restrictions, education/outreach

– Increased industrial and residential efficiency

Regional partnerships, expanded supply

Reclaimed water for non-potable uses– OWASA/UNC partnership, 11% of water demand

Reclaimed water for potable uses– Indirect potable reuse and direct potable reuse

Indirect potable reuseThe reuse of wastewater for drinking after it has been cleaned and discharged into an environmental buffer

Source: City of San Diego

Indirect potable reuse• Wastewater is treated to drinking

water standards• Water is returned to landscape– e.g., river, reservoir, constructed wetland

• After retention and mixing with the natural system, water is taken up again as drinking water

“Planned” versus “de facto”

Source: California Department of Water Resources

De facto: unplanned potable reuseof treated wastewater(NRC 2012)

Benefits of indirect potable reuse• Reliable water source under local

control• Potentially cost effective in long term• Potentially energy saving• Less water needs to be pumped from

“raw” water sources– More water available to sensitive ecosystems

Challenges of potable reuse• Public perception of “toilet to tap”

Source: National Museum of Australia / Rod Clement

Challenges of potable reuse• Public perception of “toilet to tap”• Cost in context? Varies widely due to

site-specific factors• “Unregulated pharma”• May reduce downstream flows • Regulatory framework

– e.g., separation of output from intake– S.L. 2014-113 now facilitates greater potable reuse

Case studies

Case studies close to home• City of Raleigh, Lake Benson (in

process)• Clayton County, Georgia– Constructed wetlands

• Orange County, Florida– Groundwater recharge

• Upper Occoquan, Virginia

Recommendations• Investigate further– Feasibility studies, applicable case studies,

current research

• Consider risks in context – NRC study suggests potable reuse may be

safer

• Evaluate alongside other options– including direct potable reuse

• Public education and involvement

Thank you!

Photo credit: José Manuel Suárez, 2008

Sources• EPA -- "Water Recycling and Reuse: The Environmental Benefits" webpage• http://www.epa.gov/region9/water/recycling/

• EPA -- Water Availablity• http://water.epa.gov/infrastructure/sustain/availability_wp.cfm

• IPR graphic came from • City of San Diego "Water Purification Demonstration Project" fact sheet (on my computer as SanDiegoFactSheet.pdf)• http://www.sandiego.gov/water/purewater/demo/projectreports/index.shtml

• California info:• http://www.water.ca.gov/wateruseefficiency/• link to "DWR RELATED LINKS" - Recycled Municipal Water links to pdf on my computer called CalifRecycledMunicipal.pdf• - "Indirect reuse" is the use of recycled water indirectly after it has passed through a natural body of water after discharge from a wastewater treatment plant.

• City of Raleigh• http://www.raleighnc.gov/environment/content/PubUtilAdmin/Articles/ReuseWaterSystem.html

• Clean Water series / NC Now / UNCTV• https://www.youtube.com/watch?v=EW04JFXjx3M• https://www.youtube.com/watch?v=2_mXNzbeLik• https://www.youtube.com/watch?v=k54CDzFFtsA

• OWASA website• - 11% total water demand is from cleaned wastewater

• benefits of reclaimed water (from OWASA appendix)• - reduced community's risk to drought and other water emergencies• - generally continuous, unaffected by climate• - under local control• - lower cost (than using potable)

• Land use map for Orange County:• CH5_amendmentsREVISED020712.pdf• from Orange County 2030 Comprehensive Plan, chapter 5 "Land Use Element"• http://www.orangecountync.gov/departments/planning_and_inspections/2030_comprehensive_plan.php• NOTE:• 10-year transition• 20-year transition• commericial transition activity node• Commercial-industrial transition activity node• economic development transition activity node

• 2040 triangle map projection• http://renci.org/news/researchers-forecast-150-percent-rise-in-developed-land/• RENCI (Renaissance Computing Institute)

• David Bonk, town of chapel hill pointed me to the map on the MPO website.• 919-969-5064• http://www.dchcmpo.org/programs/transport/longrange.asp; SED[1].pdf• - didn't end up using

• Jordan lake doc where the graph came from• http://www.google.com/urlsa=t&rct=j&q=&esrc=s&source=web&cd=9&ved=0CE4QFjAI&url=http%3A%2F%2Fwww.jordanlakepartnership.org%2Fuploads%2F1%2F3%2F0%2F2%2F13025771%2Fowasa_application_final.docx&ei=OvGbVdiXDYOXgwSb0YOwCA&usg=AFQjCNHSpOXw_aAKZcWBHmCSlFTspKhTrQ&sig2=qtwA5Wga8_HHTJCgS4UceQ&bvm=bv.96952980,d.eXY

• blue line clip art:• http://www.schoolclipart.biz/free-clipart-water-pollution-images-rivers-17599/free-clipart-water-pollution-images-rivers-water-conservation-trager-water-report-image/

• Upper Occoquan Service Authority• http://uosa.org/DisplayContentUOSA.asp?ID=10000354

• Water Environment Research Foundation• http://www.werf.org/i/ka/Water_Reuse/a/ka/WaterReuse.aspx?hkey=ab697e31-ac7a-4e3b-9fe0-a4168bd1cd6f

• read this -- lots of info• http://labsofcwea.com/category/reuse-recycling/page/2/

• Sustainable solutions for a thirsty planet• http://www.athirstyplanet.com/real_life/success_stories

• GE site on survey attitudes:• https://www.gewater.com/kcpguest/categoryLanding.do?path=documents/Category_Templates/English/Consumer%20Survey%20Results/guests/water-reuse-survey.html

• NYT article -- good overview• http://www.nytimes.com/2012/02/10/science/earth/despite-yuck-factor-treated-wastewater-used-for-drinking.html?pagewanted=all&_r=3&

• pro/con article• http://wordpress.vermontlaw.edu/environmentalhealth/2013/03/16/indirect-potable-reuse-the-solution-to-future-water-shortages/

• scholarly article from 2009• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2672392/

• a generally pro article• http://blogs.kqed.org/climatewatch/2011/10/30/toilet-to-tap-water-recycling-might-be-in-your-future/

• RMC website• http://www.rmcwater.com/projects/water_recycling.html

• Water Online -- "Direct Potable Reuse Vs. Indirect: Weighing The Pros And Cons"• http://www.wateronline.com/doc/direct-potable-reuse-vs-indirect-weighing-the-pros-and-cons-0001

• Phone conversation with Peter Raabe, American Rivers, 202-441-6174:• SB163• can build direct potable reuse• health department -- if you're taking in treated wastewater, what about failure within the wastewater sytem, need safety guards, back up systems, to • make sure we're not putting untreated wastewater....• - water quality coming out of the facility is often better than raw surface water• - unregulated pharma; might be creating a higher density in the raw water as opposed to surface/aquifer (problem is that they are unregulated -- should not'be in wastewater effluent in the first place -- we should regulate those toxins...)• New law• - pumped from WTP to a small holding pond where there's a mixture of 20% effulent (80% raw) then pumped to drinking water (a day's supply of water)• - appease the health department... no ww pumped directly to drinking water

• facility, so if failure it will be in the pond not in the facility• What about de facto• e.g., goldsboro drinking 30-40% of effluent from Raleigh• partner with johnson county water to drink their own wastewater...• p.25 of the 30-pg doc

• kenny waldrup, asst pub utilities director• ed bucken? water conservation director for raleigh

• Phone conversation with Bill Holman, Conservation Fund, 919-951-0119• raleigh pilot -- let it flow into lake benson (backup source)• -still in planning feas eng stage• orange county ca -- pump into aquifer, withdraw• fla - land application of treated wastewater, recharging aquifers and

• withdrawn

• concerns with...• greenville nc• taking treated wastewater, pumping into aquifer, planning to be able to draw

• water from that aquifer (water banking)• otherwise take it from tar river• salt wedge gets pretty high during drought• treated wastewater pumping is different pH than natural groundwater; issues

• about flow, reaction to minerals, etc.

• chemicals used to treat the water, pumped into limestone is creating

• problems

• nc health based drinking water rules that require a separation between

• wastewater discharges and drinking water intakes• - raleigh pilot... needed a waiver cuz dicharge in lake benson is too close

• to withdrawal point

• arguments of "reclaimed / highly treated" get more flexibility -- so far

• legislators are resistant

• "water fit for purpose"

• very little state or federal assistance -- saved for more needy communities

• (raleigh is not one)