Municipal Utilities Department 

Public Notification - Total Trihalomethanes (TTHMs)

The City recently provided a notice to all of its water customers that a drinking water standard was recently violated.  This notification provides information regarding total trihalomethanes (TTHMs).

TTHMs are compounds formed when chlorine, a disinfectant used in water treatment to kill harmful bacteria, viruses and other microorganisms, comes in contact with naturally occurring matter found in surface waters which make up 85 to 90 percent of the City of Stockton's water supply source. 

While the City's primary concern is for the proper disinfection of water, there are certain conditions typically found in winter and spring months when the level of naturally occurring organic matter remains in the water after the water treatment process to react with chlorine to form disinfection byproducts (DBPs) such as TTHMs. 

These compounds, which are regulated by the Federal Environmental Protection Agency (EPA) and California Department of Public Health, have the potential to cause health effects from long-term exposure above the maximum contaminant level (MCL) such as liver, kidney or central nervous system problems or an increased risk of cancer.  However, DBPs are not considered an immediate health threat and, as such, the City is required to notify its customers within 30 days of its knowledge of a violation. 

Samples taken from 19 locations throughout our water distribution system showed that 4 locations exceeded the MCL of 80 parts per billion (ppb).  One ppb (or µg/L), is equivalent to one half of a teaspoon of water in an Olympic-sized swimming pool. 

The City is taking immediate steps to change water sources, modify its treatment process and conduct system-wide flushing beginning this month.

For more information on DBPs, please visit the EPA and Drink Tap in External Links below. 

About MUD

The Municipal Utilities Department (MUD) is responsible for the operations of the three water utilities: water, wastewater and stormwater.  Water, wastewater, and stormwater utilities are important services for everyday life.  You may not think about your clean drinking water source, or where the water goes when you flush, but we do.

At the Municipal Utilities Department (MUD), we are committed to providing the community with:

• A stormwater system that decreases the risk of street flooding
• Disposal of carefully treated wastewater
• Education on water conservation and pollution prevention
• Environmental stewardship
• Projects that improve the quality of our waterways, lakes, and the Delta
• Safe drinking water
• Top quality customer service

Work performed by MUD is in accordance with applicable regulations and responsible business practices.  A Business Plan has been developed to guide the Department in daily operations and service.

General information about water, wastewater, and stormwater utility services, including information for residents and businesses, permit requirements and regulations, fee calculators, industrial pretreatment, and the Fats, Oils, and Grease (FOG) Program can be found under Utility Services.

Each month, a Monthly Operations and Maintenance Report (MOMR) is prepared that details the operations of the Department.

Tours of the Regional Wastewater Control Facility are available along with birdwatching opportunities in our wetlands.  More information can be found under Utility Services on the Regional Wastewater Control Facility-Plant Tours and Birdwatching page. 

MUD protects both the environment and the community by caring for the City’s water resources.

The Regional Wastewater Control Facility is a 24/7 operation that treats residential, commercial, industrial, and institutional wastewater throughout the City and parts of the surrounding County.

The Department also maintains the water operations to provide safe, reliable drinking water, and a stormwater utility that helps prevent street flooding and improves the water quality of our rivers and the Delta.

Department Divisions

MUD works to serve you. The department consists of 12 divisions, including:

• Engineering
• Environmental Compliance
• Stormwater
• Water Operations
• Wastewater
• Water Resources Planning

For additional information or to report a water, wastewater, or stormwater emergency, please Contact Us.

View the City of Stockton Municipal Utilities Department Organizational Chart  for more detail on how the department is structured.

External Links

Environmental Protection Agency (EPA)

EPA - Information about contaminants

Drink Tap

This City of Stockton web page last reviewed on --- 3/15/2013