Reuse of Treated water for Aquifer Recharge in the East Snake River Plain
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Reuse of Treated Reuse of Treated water for Aquifer water for Aquifer Recharge in the Recharge in the East Snake River Plain East Snake River Plain Eric Collins, R.G. GSI Water Solutions, Inc. May 1, 2008 Waste Waste
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Waste. Reuse of Treated water for Aquifer Recharge in the East Snake River Plain. Eric Collins, R.G. GSI Water Solutions, Inc. May 1, 2008. Reuse and Aquifer Recharge. News headlines and public awareness Nationally most reuse projects in four states - PowerPoint PPT Presentation
Transcript of Reuse of Treated water for Aquifer Recharge in the East Snake River Plain
Reuse of Treated water for Reuse of Treated water for Aquifer Recharge in theAquifer Recharge in theEast Snake River PlainEast Snake River Plain
Eric Collins, R.G.GSI Water Solutions, Inc.
May 1, 2008
WasteWaste
Reuse and Aquifer RechargeReuse and Aquifer Recharge
News headlines and public awarenessNews headlines and public awareness Nationally most reuse projects in four statesNationally most reuse projects in four states Idaho Reuse Conferences and new DEQ Idaho Reuse Conferences and new DEQ
guidance documentsguidance documents ESPA Comprehensive Aquifer Management ESPA Comprehensive Aquifer Management
Plan includes aquifer recharge alternativesPlan includes aquifer recharge alternatives
Presentation TopicsPresentation Topics
Wendell, Idaho Wendell, Idaho projectproject
Other related Other related reuse and reuse and recharge projects recharge projects in the regionin the region
▲Wendell
Twin Falls●
●Boise
Wendell Project SettingWendell Project Setting
Groundwater is sole source water Groundwater is sole source water supplysupply
Regional water level declines in ESPARegional water level declines in ESPA Potential curtailment of water rights for Potential curtailment of water rights for
groundwater users - uncertain long-term groundwater users - uncertain long-term water availabilitywater availability
City WWTP planned upgradesCity WWTP planned upgrades
Wendell Project ObjectivesWendell Project Objectives
Mitigate potential reductions in the City’s Mitigate potential reductions in the City’s water supply by reuse of treated water supply by reuse of treated wastewater for aquifer rechargewastewater for aquifer recharge
GSI invited by J-U-B Engineering to help GSI invited by J-U-B Engineering to help the City assess the feasibility of two the City assess the feasibility of two aquifer recharge options:aquifer recharge options:
1) Injection Wells1) Injection Wells2) Infiltration Basins2) Infiltration Basins
Wendell WWTP OverviewWendell WWTP Overview
Current facilitiesCurrent facilities Wastewater Wastewater
Facilities Plan (2007)Facilities Plan (2007) Target discharge Target discharge
rate 1.5 AF/dayrate 1.5 AF/day
Lagoons
Wendell
Wendell Conceptual ModelWendell Conceptual Model
GeologyGeology
TThin soil mantle overlying Snake River Group Basalts
Wendell Conceptual ModelWendell Conceptual Model
Shallow SoilShallow Soil
Soil generally consists of loam, clay, silt, and sandSoil generally consists of loam, clay, silt, and sand Caliche within soil profile and/or at soil basalt interfaceCaliche within soil profile and/or at soil basalt interface Permeability estimates: moderately slow to rapidPermeability estimates: moderately slow to rapid Infiltration Tests:Infiltration Tests:
Infiltrometer test near lagoonInfiltrometer test near lagoon 1.5 inches/hr1.5 inches/hr (JUB 2007)(JUB 2007)
Small scale pilot testsSmall scale pilot tests 1 - 3 inches/day1 - 3 inches/day (JUB 2008)(JUB 2008)
State W-Canal Recharge SiteState W-Canal Recharge Site 1 foot/day1 foot/day (Blew 2007)(Blew 2007)
State X1 Recharge SiteState X1 Recharge Site 3.6 feet/day3.6 feet/day (DEQ 2006)(DEQ 2006)
Wendell Conceptual ModelWendell Conceptual Model
Wendell
Lagoons
Wendell Conceptual ModelWendell Conceptual Model
Snake River BasaltSnake River Basalt
Series of basalt flows about 20-25 feet thickSeries of basalt flows about 20-25 feet thick Interbeds with unconsolidated sedimentsInterbeds with unconsolidated sediments Hosts the ESPA and is relatively transmissiveHosts the ESPA and is relatively transmissive Groundwater about 125 -150 feet deep discharging to Groundwater about 125 -150 feet deep discharging to
the west and south as springs next to the Snake Riverthe west and south as springs next to the Snake River Perched water possible from fined-grained sediments in Perched water possible from fined-grained sediments in
the interbeds the interbeds
Wendell Conceptual ModelWendell Conceptual Model
Particle TrackingParticle TrackingFlow Model Flow Model Snake River BasaltsSnake River Basalts
Wendell
Lagoons
W-Canal Recharge Project
Wendell Hydrogeologic ConsiderationsWendell Hydrogeologic Considerations
Injection Wells OptionInjection Wells Option
Specific capacity about 150+ gpm/ftSpecific capacity about 150+ gpm/ft One potential injection well could easily accommodate One potential injection well could easily accommodate
the target recharge rate of 1.5 AF/daythe target recharge rate of 1.5 AF/day Direct recharge to the aquifer – timing controlDirect recharge to the aquifer – timing control High density of wells and water rights in study area High density of wells and water rights in study area
means a small buffer zonemeans a small buffer zone
Infiltration BasinsInfiltration Basins
Dependent on the vadose zone above aquiferDependent on the vadose zone above aquifer Shallow soil has high percentage of fines and limited Shallow soil has high percentage of fines and limited
infiltration capacityinfiltration capacity Snake River basalts are highly transmissive in the Snake River basalts are highly transmissive in the
lateral direction but water is expected to travel slower in lateral direction but water is expected to travel slower in the vertical directionthe vertical direction
Wendell Hydrogeologic ConsiderationsWendell Hydrogeologic Considerations
Wendell DEQ ConsiderationsWendell DEQ Considerations
Injection Wells OptionInjection Wells Option
Injection wells Injection wells not allowednot allowed under new under new reuse rules (RO treatment prior to reuse rules (RO treatment prior to injection was acceptable)injection was acceptable)
Vadose zone injection wells also not Vadose zone injection wells also not allowedallowed
Wendell DEQ ConsiderationsWendell DEQ Considerations
Infiltration BasinsInfiltration Basins
Allowed if Rapid Infiltration Land Treatment (RI) is Allowed if Rapid Infiltration Land Treatment (RI) is incorporated in treatment processincorporated in treatment process
((IDAPA 58.01.16 and 58.01.17)IDAPA 58.01.16 and 58.01.17)
Groundwater Quality Rule (Groundwater Quality Rule (IDAPA 58.01.11IDAPA 58.01.11)) Buffer zone (Well Location Acceptability Analysis) - Buffer zone (Well Location Acceptability Analysis) -
potential groundwater monitoringpotential groundwater monitoring New DEQ guidance available:New DEQ guidance available:
(Guidance for Reclamation and Reuse of Municipal and Industrial Wastewater Rapid (Guidance for Reclamation and Reuse of Municipal and Industrial Wastewater Rapid Infiltration Land Treatment, April 2008)Infiltration Land Treatment, April 2008)
Wendell Water Rights ConsiderationsWendell Water Rights Considerations
Does DWR allow reuse aquifer recharge as Does DWR allow reuse aquifer recharge as mitigation for out-of-priority diversions from mitigation for out-of-priority diversions from groundwater?groundwater?
There are no projects in Idaho where DWR has There are no projects in Idaho where DWR has approved this concept. However, Idaho may follow approved this concept. However, Idaho may follow the trend set by other states.the trend set by other states.
Wendell Project SummaryWendell Project Summary
No injection wellsNo injection wells RI basins for aquifer recharge may be feasible but a few issues still need to be addressed:RI basins for aquifer recharge may be feasible but a few issues still need to be addressed:
Shallow soil infiltration capacityShallow soil infiltration capacityUnderstanding of flow path through basaltsUnderstanding of flow path through basaltsSecuring mitigation credit from DWRSecuring mitigation credit from DWR
The City is currently conducting small-scale pilot testing to further assess infiltration ratesThe City is currently conducting small-scale pilot testing to further assess infiltration rates Also consulting with DWR regarding mitigation credit Also consulting with DWR regarding mitigation credit
Other Projects in the RegionOther Projects in the Region
State W-Canal projectState W-Canal projectWendell area Wendell area
ASR projectsASR projectsBoise areaBoise area
Reuse projectsReuse projectsMountain Home AFBMountain Home AFB
Reuse and aquifer rechargeReuse and aquifer rechargeBoise area planned community developmentsBoise area planned community developments
Closing RemarksClosing Remarks
With increasing stresses on the water With increasing stresses on the water supply in this region of Idaho, treated supply in this region of Idaho, treated water reuse and managed aquifer water reuse and managed aquifer recharge will likely develop as it has in recharge will likely develop as it has in other states.other states.
Legislative funding, regulatory attention, Legislative funding, regulatory attention, and community perceptions are positive and community perceptions are positive indicators.indicators.
