2024.04.04 Attachment to Agenda Item 5 Water Supply Augmentation SeelosWater Supply Augmentation
Mark Seelos
Water Resources Manager
April 4, 2024 1
Outline
2
1. Water Supply Challenges
2. Groundwater Development Process
3. Challenges in South Tahoe
4. Desk Study
5. Next Steps
Water Supply Challenges
3
Supply Shortage in Stateline Zone
Firm Capacity: Suppliers must meet
Maximum Daily Demand with largest unit
offline (CCR Tit. 22, § 64554)
Kennedy Jenks, 2022
Bayview Well offline: Short of MDD in
Stateline Zone by 1,250 GPM.
Water Supply Challenges
4
Low Pressure at the Y
Maximum Pressure
•Model Simulation of 72-hour
period of MDD (Taylor Jaime)
•Pressures near H Street Zone:
<20 PSI - 60 PSI
Minimum Pressure
Water Supply Challenges
5
Supply Vulnerability in Meyers
Firm Capacity excess of ~965 gpm, but:
•Bakersfield Well produces ~60% of
water in Meyers and is threatened by
rising Arsenic.
•45% of pumping capacity in Meyers
requires wellhead treatment to meet
water quality standards.
•Lost redundancy in Meyers reduces
redundancy in Stateline Zone via
Gardner Mountain.
Sample Date
Ar
s
e
n
i
c
(
p
p
b
)
Bakersfield Well Arsenic
MCL
Water Supply Challenges
6
Increasing Water Demand
2023 Demand: 6,438 AFY
2045 Demand: 6,972 AFY
(2020 UWMP District Demand + 10%)
Full buildout: 10,808 AFY
(2020 Water Demand Analysis)
MDD ↑↑↑
Water Supply Challenges
7
Options for Augmentation (Stateline)
Upsize Existing Wells
•Good candidates (Sunset and Helen)
have lower than average yield.
•Deepening may have unpredictable
impacts to WQ.
•Questionably cheaper than new well.
Add Wellhead Treatment
•Airport Arsenic Treatment (2032)
•Low yield (500 gpm) without treatment.
•Tedious maintenance and disposal.
Construct New Production Wells
•Unpredictable yield and water quality.
•Limited locations remaining.
•May require modifications of distribution
system.
Augment with Surface Water
•Predictable water quality and quantity.
•Lengthy water rights process.
•Expensive facilities and water treatment
without filtration exemption.
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Groundwater Development Process
St
e
p
1
Desk Study
St
e
p
2
Test Holes
St
e
p
3
Well
Construction
2024 Desk Study
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Determine ideal locations for a new well that would optimize:
Water Quality Water Yield System Needs
2024 Desk Study
10
Goal: Identify best locations/depths for water quality.
•Water Quality is the result of
local geology.
•Meet MCLs without wellhead
treatment.
•Avoid corrosive or scaling
water.
•Analysis to identify factors
contributing to good WQ.
Wells have different chemical signatures.
2024 Desk Study
11
Goal: Identify best locations/depths for yield.
•Specific Capacity: gpm/ft
•Higher SC, Higher Yield.
2024 Desk Study
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Complicated Underlying Geology
2024 Desk Study
13
Goal: Identify best location in Stateline Zone
Sierra Tract
Fair Meadow
Test Hole Locations
14
Sierra Tract
Tanglewood
Chris
Fountain
Former shallow well (156’) from 1946-2013.
SC = 65 gpm/ft @ construction (excellent)
2 former wells from 1950-2001
Purchased in 1993
Test Hole Locations
15
Fair Meadow
ERB
CTC
Pioneer WL
Test Hole Success and Costs
16
Test Hole Success
•3/9 Suitable
Test Hole Costs per Hole:
•$167k (Rudimentary)
•$525k (Comprehensive)
Well Facility Cost
•~$2.2M (medium, no
treatment).
•~$0.75M Backup Power
Total Project: ~$5M
0
1
2
3
4
5
6
7
Suitable Suitable w/
Treatment
Not Suitable
Test Well Success (2000-Present)
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Ma
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g
a
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e
s
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Throwing Darts
Questions?
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