PUBLIC HEARING TO CONSIDER ADOPTION OF THE
CITY OF LATHROP 2026 CONSOLIDATED TREATMENT
FACILITY (CTF) CAPACITY CHARGE REPORT
AND RECOMMENDED CAPACITY CHARGE
CITY COUNCIL REGULAR MEETING | JUNE 8, 2026 | ITEM: 5.1 Presented by: Brad Taylor, Public Works Director/City Engineer CITY OF LATHROP | PUBLIC WORKS DEPARTMENT
BACKGROUND & STUDY OVERVIEW
2 WHY THIS CHARGE IS NEEDED
• No formally adopted, cost-based
capacity charge has existed —
developers paid informally through
development agreements.
• Phases 3 & 4 CTF expansions are
planned to serve growth through
buildout (2040).
• Population projected to grow from
~38,600 today to 95,000+ by 2040,
requiring major capacity expansion.
• Goodwin Consulting Group prepared
the 2026 CTF Capacity Charge Report
per Gov. Code § 66013.
STUDY KEY FACTS
Prepared by: Goodwin Consulting
Group, Inc.
Date: March 31, 2026
Planning Horizon: City buildout,
projected 2040
Methodology: System-plan cost
allocation (Gov. Code § 66013)
Cost Basis: Wastewater flow
(gallons/day) — not land use type
THE WASTEWATER SYSTEM: FACILITIES & GROWTH
3 CURRENT SYSTEM (~3.45 MGD) PLANNED EXPANSION
• CTF Phases 1 & 2: built 2004,
expanded to 2 MGD
• 14.7% share of Manteca-Lathrop
MWQCF provides 1.45 MGD
additional capacity
• Intertie can redirect all City flows to
CTF; River Outfall discharges to San
Joaquin River
• CTF Phases 3 & 4: designed to serve
City at buildout; construction
estimate ~$90.2M (GSE Construction)
• Total system capacity after
expansion: 7.65 MGD
• Growth drivers: CLSP Phase 2, River
Islands Phase 2, citywide infill —
buildout ~95,065 residents + 58,403
jobs (2040)
HOW THE CHARGE IS CALCULATED
4 Capacity Charge = Total System Cost ÷ Total System Capacity (gallons/day) PHASES 1 & 2
(Existing)
Total Cost
$147,565,319
Capacity
3.45 MGD
$42.77/GPD
PHASES 3 & 4
(Planned)
Total Cost
$109,771,236
Capacity
4.20 MGD
$26.14/GPD
TOTAL SYSTEM
(System-Wide Average)
Total Cost
$257,336,555
Capacity
7.65 MGD
$33.64/GPD
Phases 1 & 2 costs updated to 2026 dollars via ENR Construction Cost Index. Phases 3 & 4 costs reflect present value of 15-year bond financing at 6%. Each new connection pays $33.64/GPD × its estimated daily wastewater flow.
PROPOSED CAPACITY CHARGE
5 Land Use Flow Factor Est. Charge per Unit
Low Density Residential 240 gpd / unit $8,074 / dwelling unit
Medium Density
Residential 200 gpd / unit $6,728 / dwelling unit
High Density
Residential 110 gpd / unit $3,700 / dwelling unit
Commercial 755 gpd / acre $25,398 / acre
Dry Warehouse 172 gpd / acre $5,786 / acre
Limited Industrial 240 gpd / acre $8,074 / acre
$33.64
per gallon per day
(GPD)
of wastewater
treatment
capacity
WHO PAYS & LEGAL AUTHORITY
6 WHO PAYS THIS CHARGE LEGAL AUTHORITY (GOV. CODE § 66013) Applies ONLY to new connections —
existing residents and businesses are
NOT affected.
• Developers seeking final
subdivision or parcel map approval
for new residential subdivisions.
• Builders of new commercial,
industrial, or warehouse buildings
(charged at building permit).
• Collected prior to final map
approval or building permit
issuance.
No impact to current monthly sewer
bills for existing residents or
businesses.
• Authorizes local agencies to impose capacity
charges for water and sewer connections.
• Charge may not exceed reasonable cost of
providing wastewater treatment capacity.
• Costs must be proportional to each
connection's demand on system capacity
(gallons/day).
• This is a utility capacity charge — NOT a
development impact fee under Gov. Code §
66000.
• Public hearing required; cost data available to
public at least 10 days before hearing.
• Effective: 60 days following Council adoption
(~August 7, 2026).
RECOMMENDATION
8 Public Process
1 Notice published per Gov. Code § 6062a — at least 10 days before hearing. 2 Charge Report available for public review at least 10 days prior (Attachment B). 3 Public Hearing — June 8, 2026: all written and oral testimony considered. 4 If adopted, effective date: ~August 7, 2026 (60 days following adoption).
City Staff Request that City Council:
• Hold a public hearing and consider all submitted information and public testimony. • Consider adopting a resolution to approve the 2026 CTF Capacity Charge Report (March 31, 2026) and the maximum cost-justified Capacity Charge of $33.64 per gallon per day, per Government Code § 66013.