Equus Beds ASR Program – Equus Beds ASR Program – Wichita’s Future Water SupplyWichita’s Future Water SupplyEquus Beds ASR Program – Equus Beds ASR Program – Wichita’s Future Water SupplyWichita’s Future Water Supply

September 6, 2012September 6, 2012

Wichita Public Works & UtilitiesWichita Public Works & Utilities

186 mi2 Service Area 425,000+ Served

128,905 Residential Customers 13,291 Commercial Customers

160 MGD Lime Softening Plant Average Day Demand 60 MGD

186 mi2 Service Area 425,000+ Served

128,905 Residential Customers 13,291 Commercial Customers

160 MGD Lime Softening Plant Average Day Demand 60 MGD

Wichita Water Utilities Sources of WaterWichita Water Utilities Sources of Water

Wichita Well Field

Little Arkansas River

Arkansas River

Cheney Reservoir

Burrton

Bentley Reserve

Well Field

Wichita

Local Well Field

Cheney Reservoir – 1965

80MGD

Equus Beds Well Field – 1940s+55 Wells – 78 MGD

Bentley Well Field6 Wells – 10 MGD

Local Well Field19 Wells – 34 MGD

Equus Beds AquiferEquus Beds Aquifer

1,400 square miles 4 Counties 2,000 Non-Domestic Water Wells 157,000 acre-feet Withdrawn Annually

1,400 square miles 4 Counties 2,000 Non-Domestic Water Wells 157,000 acre-feet Withdrawn Annually

Projected Water Supply DemandsProjected Water Supply Demands

Average Day Demand Projections

Peak Day Demand Projections

Average Day Capacity

Max Day Capacity

2000 2005 2010 2015 2020 2025 2030 2035 2040 2045 2050

YEAR

0

50

100

150

200

250

Mill

ion

Gal

lons

per

Day

Demand 1992 2050

Average Day 60 MGD 112 MGD

Max Day 125 MGD 225 MGD

Integrated Local Water Supply Plan (ILWS Plan)Integrated Local Water Supply Plan (ILWS Plan)

Approved 1993 Meet 2050 Water Demands

Principle Component 100 MGD ASR Program

Approved 1993 Meet 2050 Water Demands

Principle Component 100 MGD ASR Program

Equus Beds – Water Level DeclineEquus Beds – Water Level Decline

Since 1940 agricultural and municipal pumping created a depression

65 billion gallons available for storage (to return to 1940 water levels)

Since 1940 agricultural and municipal pumping created a depression

65 billion gallons available for storage (to return to 1940 water levels)

More than 30 feet of water-level decline since 1940

Equus Beds – Chloride MigrationEquus Beds – Chloride Migration

Studies demonstrate chloride will migrate into the well field by 2050

Chlorides will exceed 250 ppm

Studies demonstrate chloride will migrate into the well field by 2050

Chlorides will exceed 250 ppm

Decline in Storage VolumeDecline in Storage Volume

ASR A Win-Win ProjectASR A Win-Win Project

Reliable & Sustainable Water Supply Source through 2050

Water Quality Protected from Salt Water Contamination

No Requirements to Curtail Irrigation Irrigators Have Lower Pumping Costs Improves Low Flows in Little Ark. River Less Land Required

Reliable & Sustainable Water Supply Source through 2050

Water Quality Protected from Salt Water Contamination

No Requirements to Curtail Irrigation Irrigators Have Lower Pumping Costs Improves Low Flows in Little Ark. River Less Land Required

Challenges to ASR ProjectChallenges to ASR Project

1st ASR Project in Kansas No Regulations in Place to Administer No Proof that Water can be Diverted

from River by Wells No Regulations in Place to Administer

Bank Storage Wells No Documentation that ASR would not

Contaminate Shared Aquifer Poor Image of City in Project Area

1st ASR Project in Kansas No Regulations in Place to Administer No Proof that Water can be Diverted

from River by Wells No Regulations in Place to Administer

Bank Storage Wells No Documentation that ASR would not

Contaminate Shared Aquifer Poor Image of City in Project Area

Scale of ASR ProgramScale of ASR Program

Ultimate Capacity to Recharge & Recover 100 MGD

80 mi2 area Recharge Facilities at Build-out

97 ASR Wells 2 Recharge Basins

ASR Wells Average Depth ~ 200 ft Average Injection Rate ~ 1 MGD

134 Monitoring Wells

Ultimate Capacity to Recharge & Recover 100 MGD

80 mi2 area Recharge Facilities at Build-out

97 ASR Wells 2 Recharge Basins

ASR Wells Average Depth ~ 200 ft Average Injection Rate ~ 1 MGD

134 Monitoring Wells

Source of Recharge WaterSource of Recharge Water

Little Arkansas River High Turbidity

Varies from 8 - 2000 NTUs High Atrazine Concentration

Varies from >1 – 50 g/L

Little Arkansas River High Turbidity

Varies from 8 - 2000 NTUs High Atrazine Concentration

Varies from >1 – 50 g/L

Surface Water can only be diverted at Above Base Flow Conditions

Expect to Recharge 120 days/year Spring & Early Fall

Surface Water can only be diverted at Above Base Flow Conditions

Expect to Recharge 120 days/year Spring & Early Fall

Typical Storm EventTypical Storm Event

Minimum Flowrate for Diversion

ASR Program SchematicASR Program Schematic

Recharge BasinRecharge Basin

Area 4.5 acres

Recharge Rate ~ 1.5 in/day

Area 4.5 acres

Recharge Rate ~ 1.5 in/day

Typical ASR Recharge WellTypical ASR Recharge Well

Recharge Tubes (3-4 per well)

ASR Phase IASR Phase I Location selected to prevent migration of

chlorides into the Equus Beds Constructed to establish a hydraulic barrier

Location selected to prevent migration of chlorides into the Equus Beds

Constructed to establish a hydraulic barrier

Phase I

City Wells

Phase I

City Wells

ASR Phase IASR Phase I

Recharge & Recovery Capacity of 10 MGD

ASR Facilities 7 MGD River Intake SWTP (7 MGD) 15 miles of pipeline 3 Diversion Wells 4 ASR Wells 2 Recharge Basins

Recharge & Recovery Capacity of 10 MGD

ASR Facilities 7 MGD River Intake SWTP (7 MGD) 15 miles of pipeline 3 Diversion Wells 4 ASR Wells 2 Recharge Basins

ASR Phase IASR Phase I

Award Winning Project Has established the hydraulic barrier

Award Winning Project Has established the hydraulic barrier

ASR Phase IIASR Phase II

Recharge & Recovery Capacity of 30 MGD ASR Facilities

River Intake (60 MGD, Equipped for 30 MGD) SWTP (30 MGD) 31 ASR Wells Recharge Basin (~ 7 MGD) 31 miles of Pipelines

Vital Statistics 950 Sheets of Design 43 Permits Obtained 51 Easements Acquired

Recharge & Recovery Capacity of 30 MGD ASR Facilities

River Intake (60 MGD, Equipped for 30 MGD) SWTP (30 MGD) 31 ASR Wells Recharge Basin (~ 7 MGD) 31 miles of Pipelines

Vital Statistics 950 Sheets of Design 43 Permits Obtained 51 Easements Acquired

ASR Phase IIASR Phase II

ASR Phase II SWTP Treatment Process Pre-Sedimentation & Ultrafiltration

Membranes to remove suspended solids Advanced Oxidation Processes (AOP) for

Virus Inactivation & Destruction of Atrazine (and other pesticides)

ASR Phase II SWTP Treatment Process Pre-Sedimentation & Ultrafiltration

Membranes to remove suspended solids Advanced Oxidation Processes (AOP) for

Virus Inactivation & Destruction of Atrazine (and other pesticides)

Intake Site

Intake Structure Model 1:5 Scale

Intake Structure Model 1:5 Scale

ASR Phase II SWTPASR Phase II SWTP

Regulatory ControlsRegulatory Controls First ASR project in Kansas – NO regulations

existed to administer Project includes restrictions on flow

conditions in the river. Class V permit from KDHE controls water

quality to wells and basins. Establishment of index well network. Installation of numerous monitoring wells

near diversion wells and recharge sites.

First ASR project in Kansas – NO regulations existed to administer

Project includes restrictions on flow conditions in the river.

Class V permit from KDHE controls water quality to wells and basins.

Establishment of index well network. Installation of numerous monitoring wells

near diversion wells and recharge sites.

Diversion WellsDiversion Wells

Appropriations require at least 56 cfs in the river during irrigation season

Drawdown less than 10 feet 660 feet from well

Recovery to regional water level in less than 7 days

No impairment to other groundwater users

Appropriations require at least 56 cfs in the river during irrigation season

Drawdown less than 10 feet 660 feet from well

Recovery to regional water level in less than 7 days

No impairment to other groundwater users

ASR Phase II – Geochemical EvaluationASR Phase II – Geochemical Evaluation Evaluate Mixing of Surface Water,

Groundwater and Equus Beds Aquifer Matrix

Preliminary Predictions: Pyrite (if present) within the aquifer matrix,

may oxidize releasing arsenic Iron will also precipitate and form a rust

coating on matrix Arsenic is absorbed onto rust

Evaluate Mixing of Surface Water, Groundwater and Equus Beds Aquifer Matrix

Preliminary Predictions: Pyrite (if present) within the aquifer matrix,

may oxidize releasing arsenic Iron will also precipitate and form a rust

coating on matrix Arsenic is absorbed onto rust

ASR Phase II – Geochemical Evaluation: Pilot StudyASR Phase II – Geochemical Evaluation: Pilot Study

Filters

Recharge QuantityRecharge Quantity 2006 – No recharge because of low flows in river. 2007- 369 million gallons recharged. 2008 – 319 million gallons recharged 2009 – 170 million gallons recharged 2010 – 89 million gallons recharged 2011 – No recharge – low flow and construction

issues 2012 – 33 million recharged to date

To date – 978 million gallons (over 3,000 AF) has been recharged.

2006 – No recharge because of low flows in river. 2007- 369 million gallons recharged. 2008 – 319 million gallons recharged 2009 – 170 million gallons recharged 2010 – 89 million gallons recharged 2011 – No recharge – low flow and construction

issues 2012 – 33 million recharged to date

To date – 978 million gallons (over 3,000 AF) has been recharged.

ASR Phases III & IVASR Phases III & IV Recharge & Recovery Capacity of 60

MGD ASR Facilities

To Be Determined Likely to consist of Diversion Wells and/or

additional diversion capacity at Phase II River Intake

Possible expansion of Phase II SWTP

Recharge & Recovery Capacity of 60 MGD

ASR Facilities To Be Determined Likely to consist of Diversion Wells and/or

additional diversion capacity at Phase II River Intake

Possible expansion of Phase II SWTP

Questions?Questions?