Estimation of Costs
INFLOW &
INFILTRATION
Meeting Date 2/25/2026
Pg 1
Assumptions
1 AGENDA
Operational
Costs
2 Cost by
volume
3 Estimate of
I&I
4 I&I Study
5 Oro Loma
Update
6 Pg 2 Meeting Date 2/25/2026
ASSUMPTIONS
NEGLIGIBLE IMPACT ON
CIP COSTS
IMPACT OF I&I VOLUME ON
COST OF SOLIDS
PROCESSING IS NEGLIGIBLE
SOME OPERATIONAL
COSTS ARE NOT
VOLUME DEPENDENT
USED FY 2025 AS
REFERENCE FOR
VARIABLE COSTS
Pg 3 Meeting Date 2/25/2026
OPERATIONAL
COSTS
Labor
Administrative
Other Government Agencies
Energy Consumption
Chemicals
Consumables
Maintenance and Repairs
Biosolids Management
OPERATIONAL
COSTS WITHOUT
LABOR & ADMIN
Pg 4 Meeting Date 2/25/2026
Independent of Volume
Volume Dependent
VARIABLE COSTS
Variable costs were calculated using the total cost in FY 25 for Electricity and Maintenance expenses as well as the usage of Sodium Hypochlorite at the Plant.
The total variable cost in FY25 was $1,362,611 and the volume of water treated in that period was 1745 Million Gallons (MG) with a per volume variable cost of $781/MG. $666,297
$382/MG
ELECTRICITY
$284,180
$163/MG
SODIUM
HYPOCHLORITE
$412,134
$236/MG
MAINTENANCE
Pg 5 Meeting Date 2/225/2026
Fiscal Year Total Flow (MG) Percentage I&I Estimated Cost due to I&I 2022 1728 5.91% $79,759
2023 2002 18.8% $293,950
2024 1844 11.81% $170,083
2025 1745 6.84% $93,219
ESTIMATING I&I
Estimation of current I&I was calculated using this formula:
Total Yearly Flow -[Average Daily Dry Weather Flow]*365 Average Daily Dry Weather Flow= average June -August daily flow over last 4 years • Average Yearly Dry Weather Flow = 1626 MG
• Variable Cost = $781/MG
Pg 6 Meeting Date 2/25/2026
I&I STUDY
Targeted approach to identify areas contributing to
Inflow and Infiltration.
Narrowing location of problem areas and prioritizing fix based on precise data from real world measurements.
Pg 7 Meeting Date 2/25/2026
Initial Study Cost: 30 -40K
Follow up detailed study based on results of initial study
ORO LOMA UPDATE
On track to implement ordinance July 1, 2026
Open to discussing managing a PSLO program
for City’s wastewater service area if it is
determined to be mutually beneficial.
Pg 8 Meeting Date 2/25/2026
Pg 9 Meeting Date 2/25/2026
QUESTIONS