HomeMy WebLinkAboutStaff Report 14611
City of Palo Alto (ID # 14611)
Finance Committee Staff Report
Meeting Date: 11/29/2022 Report Type: Action Items
City of Palo Alto Page 1
Title: Discussion and Update on Sanitary Sewer Main Replacement
Acceleration Alternatives
From: City Manager
Lead Department: Utilities
Recommendation
This item is for the Finance Committee’s discussion and feedback; no action is requested.
Discussion
There are 138 miles of remaining clay sanitary sewer mains that need to be replaced before
they exceed their approximately 100-year life expectancy, which would require an annual
replacement of around 2.5 miles per year. Current wastewater rates support an annual rate of
replacement of around 1 mile per year. Staff seeks input from the Finance Committee on how
quickly to move to a 2.5 mile per year rate of sanitary sewer main replacement given the
associated increase of customer wastewater collection rates necessary to fund the
improvements.
The brief summary below describes three alternative approaches to accelerate the sanitary
sewer main replacement and illustrate the preliminary rate increase projections needed to
achieve the proposed 2.5 mile per year main replacement for each alternative based on a pay-
go financial model and a debt financing model. Staff will continue to update and refine these
estimates based on changing economic conditions and the availability of updated financial
information from the Fiscal Year 2022 Year-End process.
• Alternative #1: immediately move to 2.5 miles per year of sanitary sewer main
replacement starting in FY 2024
• Alternative #2: transition to 2.5 miles per year of sanitary sewer main replacement over
four years and begin the program in FY 2026
• Alternative #3: transition to 2.5 miles per year of sanitary sewer main replacement to
keep rate increases below 5%; program estimated to start in FY 2034
Once equipment reaches the approximate 100-year life expectancy, the risks or maintenance
the City may experience include:
• Increased maintenance to clear blockages and perform spot repairs
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• Increased frequency of sanitary sewer overflows
• Increased volume of sewage discharged per sanitary sewer overflow event
• Increased cost to replace failed infrastructure
• Increased potential for sinkholes at locations of failed infrastructure
• Potential additional liability associated with sanitary sewer overflows
While reviewing and receive feedback on this important maintenance schedule, the City’s
Regional Water Quality Control Plant is going through significant capital investment in parallel
that will also impact rates during this same period. A key project to upgrade the secondary
stage of the wastewater treatment system for the City’s Regional Water Quality Control Plant of
which the City is responsible for 38.16% of the capital investment ($169 million, financing at
$193 million). The Secondary Treatment Upgrades (STU) project will be financed by the state
low-interest SRF loan program and be repaid by Palo Alto and its five partner agencies. The
project was identified in the 2012 Long Range Facilities Plan (LRFP). Construction is expected to
start in early 2023 and the improvement is expected to be completed around November 2027.
Loan payments on the debt service will begin in 2028. This timing is important for the
discussion on impact to the rates. Further details on rates follows the alternative approaches
to accelerate the sanitary sewer main replacement
Three alternative approaches to accelerate the sanitary sewer main replacement
Alternative 1
The first alternative is to immediately move to 2.5 miles per year of sanitary sewer main
replacement starting in FY 2024. Subsequent projects will replace 5 miles of sewer mains every
two years. At this replacement rate, the last clay sewer mains would be replaced when they
are 107 years old. This alternative could be financed either using pay-as-you-go financing with
funds collected from rates (Alternative 1a), or using a utility revenue bond of an estimated
$12.6 million to fund the sewer main replacement work planned for FY 2024 and FY 2025
(Alternative 1b).
Under Alternative 1a, staff estimates rate increases of 15% and 12% in FY 2024 and FY 2025
would be needed followed by 3% to 4% annual rate increases throughout the forecast period.
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Figure 1: Alternative 1a – Immediate Move to 2.5 miles/year Pay-Go Finance 5-mile Project in
FY 2024
Under Alternative 1b, staff estimates rate increases of 7% annually over the next seven years
followed by 3% annual rate increases throughout the forecast period.
Figure 2: Alternative 1b – Immediate Move to 2.5 Miles/Year, Debt Finance 5-mile Project in
FY 2024
However, when compared to the other alternatives, Alternative 1b is expected to cost the City
approximately $11,000,000 extra for bond financing and $3,400,000 for loan financing from the
California State Revolving Loan (SRF) Fund over the duration of the financing period. Given the
competitive nature of SRF loans, there is no guarantee the City’s SRF application would be
funded.
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Alternative 2
The second alternative is to transition to 2.5 miles per year of sanitary sewer main replacement
over four years and begin the program in FY 2026. Subsequent projects will replace 5 miles of
sewer mains every two years. At this replacement rate, the last clay sewer mains would be
replaced when they are 109 years old. Under Alternative 2, staff estimates rate increases of 9%
annually for the next three years (FY 2024 through FY 2026), and 8% in FY 2027, followed by
annual 3% rate increases throughout the forecast period.
Figure 3: Alternative 2 – Transition to 2.5 Miles/Year Over Four Years, 5-Mile Project in FY 2026
Alternative 3
The third alternative is to transition to 2.5 miles per year of san itary sewer main replacement
slowly to keep rate increases below 5%. Staff anticipates that the 2.5 miles per year
replacement program would start in FY 2034. Subsequent projects will replace 5 miles of sewer
mains every two years. At this replacement rate, the last clay sewer mains would be replaced
when they are 113 years old. Under Alternative 3, rate increases are limited to 5% annually.
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Figure 4: Alternative 3 – Transition to 2.5 Miles/Year Slowly To Keep Rate Increases Low, 5-Mile
Project in FY 2034
Waste Water Collection Rates
Staff plans to return to the Finance
Committee with Preliminary
Financial Forecasts in February 2023
and with proposed Financial Plans
and rates in April 2023. However,
for context to assist the committee
in the review of these alternatives,
below is a graph from Silicon Valley
Clean Water’s Proposed 2021-22
Operating Budget representing the City’s current residential rate of $ 44.62 compared of
neighboring agencies. The City has historically enjoyed low residential wastewater rates
compared to neighboring agencies. Rate increases are expected to support inflation, the
cashflow needs of the capital investments being made at the RWQCP, and the debt payment for
the significant capital investments, along with the alternative scenarios for discussion above.
The scenarios above do have some modeling for the RWQCP capital needs in the “Treatment
Capital & Debt” section of the alternative forecasts above, though cost of these capital
improvements continue to exceed engineer estimates in this environment.
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Stakeholder Engagement
At the Utilities Advisory Commission (UAC) April 2022 meeting, staff presented the need to
increase the rate of sewer main replacement from 1 mile per year to 2.5 miles per year in order
to replace the remaining 138 miles of sewer mains scheduled for replacement before they
exceed their expected life. UAC Commissioners expressed support for increasing the rate of
sewer main replacement to 2.5 miles per year. At the UAC’s October 12, 2022 meeting, staff
presented the same attached three alternative approaches to accelerate the sanitary sewer
main replacement (Staff Report #14610). UAC Commissioners asked questions about the causes
of sanitary sewer overflows, and asked whether pipes are prioritized based upon condition.
Staff responded that sanitary sewer overflows can be caused by leaks or blockages and that
pipes are targeted for cleaning and prioritized for replacement. A UAC Commissioner asked a
question about climate change and sea level rise impacts on the sewer mains. Staff responded
that as part of the upcoming sewer master plan study, staff will work with the consultant on
examining these impacts. One Commissioner stated that Alternative 1a or 1b (only with SRF
loan) is reasonable while two Commissioners opposed Alternative 1a and 1b. Three
Commissioners supported Alternative 2 while one Commissioner questioned whether
Alternative 3 may also be acceptable. Staff responded that Alternative 3 would not allow the
City to manage sewer infrastructure on a life-cycle basis.
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