Water Pollution Control Plant
Ponds and Levees Study Session
Environmental Services Department
August 27, 2024
DRAFT PRESENTATION
2WPCP Levees and Ponds Study
Pond Levees
Algae Issues
Ponds Future
Levees Recreational Access Study Issue
Agenda
DRAFT PRESENTATION
3WPCP Levees and Ponds Study
Ponds Levees
Oxidation
Pond 2
300 Acres
Oxidation
Pond 1
100 Acres
WPCP
Inner Levee
Outer Levee
Water Pollution Control Plant
(WPCP)
Pond A4
(Valley Water)
DRAFT PRESENTATION
4WPCP Levees and Ponds Study
Timeline
2014 2016 2018 2020 2022 2024
Levee Condition
Assessment
Shoreline Project Ph III
Feasibility Study Kickoff
(US ACE & Valley Water)
Levee
Maintenance Plan
Master Plan Update
Ponds Future Use
2021 20232014
Clean Water Program
Master Plan Algae Issues
Levee Emergency
Repairs
DRAFT PRESENTATION
5WPCP Levees and Ponds Study
Levee Condition Assessment (2016) and
Operations and Maintenance Manual (2018)
Riprap Placement, ~13,000 ft
Vegetation Removal, ~19,000 ft
Levee Road Improvements, ~9,000 ft
Pond Levees - Levee Condition Assessment
DRAFT PRESENTATION
6WPCP Levees and Ponds Study
Ongoing Mechanical Vegetation Removal
Annual Cost is ~$420,000
Pond Levees - Levee Vegetation Management
DRAFT PRESENTATION
7WPCP Levees and Ponds Study
WPCP Oxidation Pond Levee Rehabilitation Project - $15M Pond 1 East Levee Project – 3, 600 ft, $2M, north section complete in 2023, south section in design.
Pond 2 South Levee – 5 ,000 ft future project
Pond 2 West/Pond 1 North Levee Emergency Repairs - $0.5M , April 2024.
Pond Levees - Levee Road Improvements
DRAFT PRESENTATION
8WPCP Levees and Ponds Study
Pond 2 Levee Seepage Spot Repair
Pond 2 North Levee Spot Repairs
Pond Levees – Emergency Spot Repairs
May 2022
Jul 2023
Nov 2023
DRAFT PRESENTATION
9WPCP Levees and Ponds Study
Single-cell blue-green algae
(<2 um, picoplankton)
Algae Issues
WPCP
Algae
Issues
Permit
Compliance
Challenges
Chemical
Management
Recycled
Water
Production
DRAFT PRESENTATION
10WPCP Levees and Ponds Study
Lake Guard Oxy® Al gae Treatment (2022)
Water IQ Ultrasonic Algae Treatment (2023)
Biological Solids Reduction (2023)
Algae Issues - Pilot Studies
DRAFT PRESENTATION
11WPCP Levees and Ponds Study
Modified Air Flotation Tanks (AFT) for In-series Treatment in Summer 2023 Portion of Effluent sent to Tank #3
Additional Chemistry in Tank #3
Successfully Improved Turbidity and Total Suspended Solids Removal 10 NTU – D ischarge Permit Requirement
×Could not Meet Recycled Water Requirement
Currently Used As Needed
WPCP
Algae Issues - Plant Modifications
DRAFT PRESENTATION
12WPCP Levees and Ponds Study
Algae Management
Targeted Algaecide Study
Ponds Operational Modifications
Evaluate Isolating Pond 1 Return
C
hannel from Recirculation Pump Station
Evaluate directing AFT float to Pond 1
Algae Issues - Future Actions
DRAFT PRESENTATION
13WPCP Levees and Ponds Study
Recycled Water Production Pilot
Cloth Media Filtration
Pilot Testing of a Cloth Media Filter
Implementation Plan for Full Scale Package Plant
0 1
2 3
4 5
6 7
8 9
10 8/6/24 8/8/24 8/10/24 8/12/24 8/14/24 8/16/24 8/18/24 8/20/24 Turbidity (NTU)
Date
AquaDisk® Cloth Media Filter Pilot Study for Recycled Water Production Pilot Influent Pilot Effluent
CA Title 22 Limit for Recycled Water
DRAFT PRESENTATION
14WPCP Levees and Ponds Study
• Ponds expected to be
r
etired in 2040
• Emergency Storage and
E
qualization in Pond 1
• Valley Water Pond A4
c
onsidered as alternative
• Master Plan Update will
r
evisit A4
Closer to Main Plant
Challenging location because
it is “Water of the US”
Ponds Future - Plant Master Plan
Storage
DRAFT PRESENTATION
15WPCP Levees and Ponds Study
2023 Feb 2024 2027 2030
Study kick-off Public Scoping
Meeting
Draft Report of
potential solutions
for public review
and comment
Final report sent to
Congress for approval
and funding for design
and construction
Ponds Future – Valley Water Partnership
Sunnyvale is in Phase III of the Shoreline Project Feasibility Study Alternatives Analysis by USACE in progress
Cost/Benefit used to determine “Federal Interest”
S
tudy Timeline:
(Subject to change)
DRAFT PRESENTATION
16WPCP Levees and Ponds Study
Shoreline Alternatives in Development
Retirement of Ponds changes
s
horeline options
Restoration o pportunity
and challenge
Interagency roles – may need
agreement
Example
Concepts
DRAFT PRESENTATION
17WPCP Levees and Ponds Study
• Led by LRS; ESD is partner
• Operational, recreational, and
e
nvironmental considerations
• Public engagement as part of
s
tudy
• Time to complete – 1-2 years
Study Issue LRS 24-01
Study Issue: Access Closure to Interior Levees
DRAFT PRESENTATION
18WPCP Levees and Ponds Study
• Ongoing Levee Maintenance and improvements needed until p
onds are retired in 2040
• Algae management will be an acute issue until Conventional A
ctivated Sludge-1 project is completed (2028)
• Chemical Management continues to be challenging
• RW Production option for Council consideration (early 2025) • Ponds restoration – an opportunity and a challenge
• Separate sea level protection plan outside of Shoreline Study m
ay be needed for Emergency storage and equalization area Summary
DRAFT PRESENTATION
19WPCP Levees and Ponds Study
Questions/Discussion
DRAFT PRESENTATION