Central Yakima ASR Programmatic FrameworkDave Brown Chris PitreCity of Yakima Golder Associates

City of Yakima –Location & Water Supply

Naches Water Treatment Plant(25 mgd / 40 cfs, ~15,000 afy)Main Supply

Groundwater Wells (~14 mgd)Backup (3-5 days at peak demand)

PEAK DEMAND = SUPPLY (25 mgd)

EMERGENCY GROUNDWATER BACKUP

PLANNING – How to meet: Drought, climate change Possible curtailment of using water rights Interruption of supply (maintenance, contamination)

Growth

City of Yakima Water Supply Responsibilities

Drought

Gordon King, Yakima Herald Republic

Total Water Supply Available (TWSA)

1905 Reservoirs

Parker Gage

City of Yakima

All surface water is allocated, and managed @ Parker Gage

3 types of water rights:• Senior (golden)• 1905 (pro‐ratable in drought)• Junior (cut off in drought)

City has each type.

Reliance on groundwater during drought may be at risk in coming droughts.

Drought/Pro-Rationing

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Minim

um M

onthly Pro‐Rationing

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DROUGHT• 13 times/41 years• 73% this year?• Next year??

Drought/Pro-Rationing

Additional Threats to Surface Water Supply

• Maintenance• High flow turbidity • Ice/debris jams of intake• Watershed forest fire• Chemical spill from HWY 12

Water Treatment Plant

Yakima

Groundwater• Groundwater and surface water: 

• Were separate (1977; Aquavella adjudication).• Now connected (2011; USGS study)

• Most groundwater rights are post‐1905 (i.e., Junior)• Now groundwater may be @ risk to be cut off in drought year?

• City needs existing wells AND more for the 4 Rs(reliability, redundancy, resilience & robustness).

• No new groundwater rights available, unless:• Significant environmental benefit• Non‐consumptive (water budget neutral)

Aquifer Storage & Recovery (ASR) fills the bill 

ASR System Components

Water Treatment PlantParker Gage

Wells

The Right Geology.• Big yield wells • Bowl‐shaped aquifer• Compatible chemistry

The Right Infrastructure.• Winter treated water supply• Big wells in bowl‐shaped basin• Gravity distribution system connecting it all together

Gardner

Kissel

The Right Geology• Aquifer is Ellensburg Formation sandstone• Mineralogy is volcaniclastics (glass)• Aerobic environment (redox reactions are not a concern)• Surface water is a dilute from of groundwater.

~1,000 feet

Recharge Zone

Naches River

Groundwater

Ellensburg Fm.

Basalt

The Right Infrastructure• All major components are in place:

• 12 MGD winter water recharge supply• Gravity transmission to 3,000 gpm wells• Kissel Well ASR retrofitted for $30k• Gardner Well installed with ASR capability

RechargeKissel Well  Production

• System scale clogging reduced Kissel Well efficiency 25% ‐ 100% restored by back‐flushing

• No clogging of Gardner Well (newer distribution system zone)

• Recharge pressure will be monitored to control clogging and conduct preventative flushing

ASR Program Development• 1998: ASR potential recognized

• 2000: Kissel Well retrofitted for ASR & tested – all’s good

• 2002: Reservoir application submitted

• 2003: State ASR rule passed

• 2009: BoR/Ecology – modeling defines recoverable quantity

• 2010: Purpose-built ASR well installed

• 2014: Gardner Well ASR Test

• 2015: Temporary permit issued 2015-02-24.

Water starts going into the ground 2015-03-11!

17 years

Why So Long?

• State policy not clear.  Permitting uncertainty:• Recoverable quantity (how much you get back)• Water quality (AKART and 5‐year variance)

• Other ASR projects working through the permitting process (state‐wide)

• Some project proponents are sitting back to let others lead

• Broad focused support for Yakima arrived through the Yakima Basin Integrated Plan

Key Permitting Point1.  Water Quantity(WAC 173‐157 – ASR Rule)

Recoverable Quantity:• Should be based on water balance analysis.  Could be by: 

• Water level data (empirical; e.g., tank level)• Computer models (needs good calibration)

• Water levels in the Ahtanum Valley are very noisy (seasonal fluctuations, other groundwater users)

• Therefore a groundwater model is used.• Aquifer system is leaky – 90% of the water is there one year after recharge… less in later years.

• A loss of 10%/year was proposed for permit.

Key Permitting Point2.  Water Quality

• Chlorinated drinking water is recharged.

• Contains chlorination disinfection byproducts (DBPs; e.g., 10‐40 ppb trichloromethane – SDWA allows 80 ppb).

• Conflicts with WA Groundwater Antidegradation Rule (WAC 173‐200 allows 7 ppb trichloromethane ).

• Variance allowed by Director of Ecology based on AKART analysis.• Variance must be reviewed every 5 years.

AKART Analysis of Different Treatment Technologies

Existing GAC RO

Cost ($M; 30‐yr NPV @ 5%) $0.6 $2.9 $23

Implementability In place. Significant engineering/construction needed.

Effectiveness THMs remain @ safe drinking water levels Removes DBPs; waste stream produced.

DBP Formation During Groundwater Storage

• Kissel well recharged in Dec.• Lower TOC = lower max DBP, Lower T      = slow time to peak

• Gardner Well recharged in June.• Higher TOC = higher max DBP Higher T      = quick time to peak

Gardner WellKissel Well

Plot to be inserted

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STORAGERECHARGE RECOVERY

Kissel Well

80 ug/L (SDWA)

• DBPs form as a function of contact time.• Rate of formation is dependent on temperature.• Chlorine dissipates in ~2‐3 weeks

7 ug/L (WAC 173‐200)

Residual Chlorine – Max @~0.6 mg/L (conceptual)

Yakima Basin Integrated PlanSince 2009, and on‐going:• Led by USBR & Ecology• Includes:

• Yakama Nation• Irrigation Districts• Fed, state, counties, municipalities• Enviros, citizens

Covers:• Surface Storage • Groundwater Storage • Fish Passage & Habitat• Modifying Existing Structures, Operations 

• Water markets• Conservation

http://www.ecy.wa.gov/programs/wr/cwp/ybip.htmlhttp://www.usbr.gov/pn/programs/yrbwep/2011integratedplan/

Meet needs of:• Farms• Fish• People

Benefits Beyond Municipal SupplyPassive Recovery:• Water leaks from storage to stream.  Water will be recharged every year – but only recovered when needed.

• Leaked water could be accounted against rural development impacts • Unrecovered water returns to the Yakima River, above Parker Gage, and increases TWSA (e.g., 3 cfs modelled) 

Active Recovery:• With 100% groundwater redundancy:

• Surface water diversion by the City could be temporarily suspended• Making 40 cfs available to others

• Could pump directly to river

Where We Stand Today• A temporary permit has been issued:

• Recharge at 2 wells (Kissel & Gardner)• Recovery at any of the City’s 4 wells• Allows full beneficial use of ASR• Allows recharge of DBPs up to 50% of drinking water levels

• A full permit is expected after addressing final AKART comments

• A new ASR well in 2016• Recharge is happening now. N

Recharge PointsRecovery Points

~3 miles

Thank You!

Dave BrownCity of Yakima

David.Brown@yakimawa.gov

Chris PitreGolder Associatescpitre@golder.com

Supported byWashington Department of Ecology  United States Bureau of Reclamation