Opportunities for Potable Reuse in the Livermore-Amador Valley

Transcription

1 Image Surce: Australian Academy f Technlgical Sciences and Engineering (ATSE) Opprtunities fr Ptable Reuse in the Livermre-Amadr Valley Brad Ledesma Assciate Engineer Integrated Planning

2 What is Zne 7?

3 WHOLESALE WATER SUPPLIER Fr Livermre Amadr Valley City f Pleasantn Dublin San Ramn Services District Delivering t Dublin and the Dugherty Valley area in suthern San Ramn City f Livermre Califrnia Water Service Cmpany

4 Zne 7 Water Agency Functins Fld prtectin fr Eastern Alameda Cunty (425 square miles) State Water Prject Cntractr, imprting an average f 48,000 acre feet annually t Valley; remaining demands (averaging 15%) met with lcal supplies Treated water whlesaler (45,000 AFA) fr ver 220,000 residents and businesses served by: City f Livermre Califrnia Water Service Cmpany (prtin f Livermre) City f Pleasantn Dublin San Ramn Services District (including Dugherty Valley under special agreement) Untreated water supplier (5,000 AFA) fr: 74 agricultural & irrigatin custmers (3,500 acres) Primarily vineyards Lcal wine industry estimated at $200 millin/year Sustainable Grundwater Manager (granted lcal authrity in SGMA) 250,000 AF undergrund basin with 126,000 AF peratinal strage Envirnmental Stewardship fr Watershed Prtectin

5 Prtecting the Livermre Valley Grundwater Basin Requires mdificatin fr any advanced treatment f recycled water Facilitates the use f Tertiary Recycled Water fr irrigatin

6 Grundwater Quantity Histrical Grundwater Elevatins at a Key Well Grund Surface Intermittent Streams December 2014 May 2015 Operatinal Range Zne 7 Artificial Recharge started in 1962 Grundwater Basin is a Significant Drught Resurce fr the entire Valley.

7 Grundwater Quality Salt Ttal salt lading has drpped 14,772 tns since 2008 Management Strategy Artificially recharging the basin with lw TDS water when available Average cncentratin has risen 70 mg/l since 2008 due t decrease in grundwater strage Mch Demin Activated Pumping and delivering additinal grundwater s mre salts are exprted as wastewater Operating the Mch Demineralizatin Facility t remve salts Prtecting surce water quality Cntinuing mnitring f TDS cncentratins

8 Grundwater Quality Nutrients Management Strategy frm Salt Nutrient Management Plan Increasing understanding f the extend and surce(s) f high nitrate cncentratins Requiring new develpment prjects within the unsewered Areas f Cncern t minimize, r when practical, install nly new advanced OWTS with nitrgen reducing treatment Cntinuing mnitring f the nitrate cncentratins

9 Extended Mining in Chain f Lakes Area Shadw Cliffs Owned and Operated by EBRPD Chain f Lakes Series f gravel pits in active mining since befre the 1960 s I H Cpe G Prvide ~100,000 acre feet f Strage F E Shadw Cliffs Zne 7 Owns: 1. Lake I 2. Cpe Lake D C B A Lake H after cmpletin f reclamatin Lakes A thru G cmpletin f mining (~2030) 2060? Additinal evaprative lsses Additinal salt lading Delay in lng term recharge plans

10 Hw culd ptable reuse fit int Zne 7 s plan and apprach fr lng-term water supplies?

11 STATE WATER PROJECT, ver 80% f Zne 7 s Water Supply Orville Reservir San Luis Reservir All f Zne 7 s Imprted Supplies are delivered thrugh the Delta/SBA System: Grundwater Banks (Semitrpic and Cawel) Table A Carryver Dry Year Transfers SWP Exchanges Multi Year Pl Semitrpic & Cawel Many uses: Deliver t custmers Recharge lcal GW Basin Carryver in San Luis Reservir Banked in Kern Cunty Pilt Ls Vaquers Strage Prgram BBID

12 Urban Water Management Plan Assesses the reliability f Zne 7 s water supplies ver a 20 year planning hrizn cnsidering nrmal, dry, and multiple dry years First plan cmpleted in 2000, and it is updated every 5 years Outlines status f existing water demand management measures Identifies planned prgrams and prjects t meet prjected water supply shrtages Defines Zne 7 s Water Shrtage Cntingency Plan Last update cmpleted in 2010 Staff currently wrking n a 2015 update, due by June 2016

13 Have been wrking with ur Lcal Retailers t Develp Rbust Analysis fr Identifying Mst Resilient Future Supply Prtflis Prvides backgrund fr UWMP and agency planning Identified ver 30 ptential water supply ptins ranging frm small grey water and rainfall capture systems t large scale recycled water systems Develped three prtflis: (1) Delta Fix centric; (2) Recycled Water centric; (3) Intertie centric Emplyed risk based apprach fr identifying near term n regret actins fr mving frward

14 Have been wrking with ur Lcal Retailers t Develp Rbust Analysis fr Identifying Mst Resilient Future Supply Prtflis Currently updating the WSE: expected cmpletin in January 2016 Prvides backgrund fr UWMP and agency planning Prvides updated data and backgrund fr UWMP, which is due June 2016 Identified ver 30 ptential water supply ptins ranging frm small grey water and Accunts fr ptential delays in the Chain f Lakes (lcal strage) rainfall capture systems t large scale recycled water systems Includes updated SWP Reliability numbers Evaluates lcal climate change Imprtant t bth water supply & fld prtectin Accunts fr Delta utages assciated with an earthquake r water quality Adds cnservatism t availability f drught supply in Kern Cunty Emplys a Rbust Apprach 4 Prtflis 8 Scenaris 8 Metrics Each subjected t different hydrlgic sequences Develped three prtflis: (1) Delta Fix centric; (2) Recycled Water centric; (3) Intertie centric Emplyed risk based apprach fr identifying HDR hired t review ptential feasible recycled water n regret actins fr mving & desalinatin ptinsnear term fr the benefit f frward the entire Tri Valley area

15 Preliminary Ptential Ptable Reuse Optins frm HDR Indirect Ptable Reuse: might be 4,800 t 7,200 AF per year $1,700 t $2,000 per acre ft Perclatin via Chain f Lakes (Lake I) A much mre detailed and rbust evaluatin f strage capacity, and perclatin ptential needed t accunt fr grundwater levels, ther recharge demands (e.g., strmwater r increased gravel pumping), and the actual timing f acquisitin.` Injectin wells (if even feasible) A much mre detailed and rbust evaluatin f the peratinal feasibility and cst f injectin wells is necessary, especially since prir experience by Zne 7 staff indicates that injectin may nt be feasible within the Livermre Amadr Valley. Dn t frget: blending and discharge requirements (NPDES & EBDA) Direct Ptable Reuse : might be 5,400 t 7,800 AF per year Regulatins are still under develpment $1,500 t $1,800 per acre ft Treat a blend f advanced treated recycled water and Delta water at PPWTP Treat a blend f advanced treated recycled water and Delta water at DVWTP Dn t frget: blending and discharge requirements (NPDES & EBDA) Direct cnnectin t ptable system

16 Wuld ptable reuse help? Cautius Apprach Ptential Advantages: Might be able t achieve increases in ttal lng term average supply by as much as 14% Increases dds f having mre water in the lcal grundwater basin t help prtect against drught r utage f SBA Mre lcal cntrl BUT Exercise due diligence t ensure the health f the public and the lcal grundwater basin are prtected Assess public pinin Assess water quality impacts t aquifer and distributin systems Identify the apprpriate number and type f physical r treatment barriers between surce water and the end user Further evaluate perclatin within Chain f Lakes and ptential cnflicts with fld prjectin needs Thrughly investigate injectin, especially since past attempts were unsuccessful due t lcal cnditins Identify Ptential envirnmental impacts and needed mitigatin Evaluate feasibility f blending and meeting discharge and permitting requirements (i.e., NPDES/EBDA) t better define yields Wrking with lcal retailers n a scpe f wrk fr a detailed public plling and feasibility study.

17 QUESTIONS? Image Surce: Australian Academy f Technlgical Sciences and Engineering (ATSE)