CITY OF STOCKTON

Consumer Confidence Report – 2025

Covering Calendar Year – 2024

This brochure is a snapshot of the quality of the water that we provided last year. Included are the details about where your water comes from, what it contains, and how it compares to Environmental Protection Agency (EPA) and state standards. We are committed to providing you with information because informed customers are our best allies. If you would like to observe the decision-making process that affect drinking water quality, please call KAYLA HILBRINK at 785-425-6703.

Your water comes from 10 Ground Water Well(s):

Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as those with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA/CDC guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (800-426-4791).

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the EPA’s Safe Drinking Water Hotline (800-426-4791).

The sources of drinking water (both tap water and bottled water) included rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity.

Contaminants that may be present in sources water before we treat it include:

Microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, livestock operations and wildlife.

Inorganic contaminants, such as salts and metals, which can be naturally-occurring or result from urban storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining or farming.

Pesticides and herbicides, which may come from a variety of sources such as storm water run-off, agriculture, and residential users.

Radioactive contaminants, which can be naturally occurring or the result of mining activity.

Organic contaminants, including synthetic and volatile organic chemicals, which are by-products of industrial processes and petroleum production, and also come from gas stations, urban storm water run-off, and septic systems.

In order to ensure that tap water is safe to drink, EPA prescribes regulation which limits the amount of certain contaminants in water provided by public water systems. We treat our water according to EPA’s regulations. Food and Drug Administration regulations establish limits for contaminants in bottled water, which must provide the same protection for public health.

Our water system is required to test a minimum of 2 samples per month in accordance with the Revised Total Coliform Rule for microbiological contaminants. Coliform bacteria are usually harmless, but their presence in water can be an indication of disease-causing bacteria. When coliform bacteria are found, special follow-up tests are done to determine if harmful bacteria are present in the water supply. If this limit is exceeded, the water supplier must notify the public.

Water Quality Data

The following tables list all of the drinking water contaminants which were detected during the 2024 calendar year. The presence of these contaminants does not necessarily indicate the water poses a health risk. Unless noted, the data presented in this table is from the testing done January 1- December 31, 2024. The state requires us to monitor for certain contaminants less than once per year because the concentrations of these contaminants are not expected to vary significantly from year to year. Some of the data, though representative of the water quality, is more than one year old. The bottom line is that the water that is provided to you is safe.

Terms & Abbreviations

Maximum Contaminant Level Goal (MCLG): the “Goal” is the level of a contaminant in drinking water below which there is no known or expected risk to human health. MCLGs allow for a margin of safety.

Maximum Contaminant Level (MCL): the “Maximum Allowed” MCL is the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.

Secondary Maximum Contaminant Level (SMCL): recommended level for a contaminant that is not regulated and has no MCL.

Action Level (AL): the concentration of a contaminant that, if exceeded, triggers treatment or other requirements.

Treatment Technique (TT): a required process intended to reduce levels of a contaminant in drinking water.

Maximum Residual Disinfectant Level (MRDL): the highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

Non-Detects (ND): lab analysis indicates that the contaminant is not present.

Parts per Million (ppm): or milligrams per liter (mg/l)

Parts per Billion (ppb): or micrograms per liter (µg/l)

Picocuries per Liter (pCi/L): a measure of the radioactivity in water.

Millirems per Year (mrem/yr): measure of radiation absorbed by the body.

Monitoring Period Average (MPA): An average of sample results obtained during a defined time frame, common examples of monitoring periods are monthly, quarterly and yearly.

Nephelometric Turbidity Unit (NTU): a measure of the clarity of water. Turbidity in excess of 5 NTU is just noticeable to the average person. Turbidity is not regulated for groundwater systems.

Running Annual Average (RAA): an average of sample results obtained over the most current 12 months and used to determine compliance with MCLs.

Locational Running Annual Average (LRAA): Average of sample analytical results for samples taken at a particular monitoring location during the previous four calendar quarters.

Testing Results for: CITY OF STOCKTON

Disinfection Byproducts Monitoring Period Highest RAA Range (low/high) Unit MCL MCLG Typical Source

TOTAL HALOACETIC ACIDS

(HAA5) 2024 24 17 - 29 ppb 60 0 By-product of drinking water disinfection

TTHM 2024 69 48 - 80 ppb 80 0 By-product of drinking water chlorination

There is no safe level of lead in drinking water. Exposure to lead in drinking water can cause serious health effects in all age groups. Infants and children can have decreases in IQ and attention span. Lead exposure can lead to new learning and behavior problems or exacerbate existing learning and behavior problems. The children of women who are exposed to lead before or during pregnancy can have increased risk of these adverse health effects. Adults can have increased risks of heart disease, high blood pressure, kidney or nervous system problems.

Lead and Copper Monitoring Period 90th Percentile Range (low/high) Unit AL Sites Over AL Typical Source

COPPER, FREE 2022 - 2024 0.059 0.013 - 0.063 ppm 1.3 0 Corrosion of household plumbing

LEAD 2022 - 2024 0 0 - 7.6 ppb 15 0 Corrosion of household plumbing

Lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. CITY OF STOCKTON is responsible for providing high quality drinking water and removing lead pipes but cannot control the variety of materials used in plumbing components in your home. You share the responsibility for protecting yourself and your family from the lead in your home plumbing. You can take responsibility by identifying and removing lead materials within your home plumbing and taking steps to reduce your family's risk. Before drinking tap water, flush your pipes for several minutes by running your tap, taking a shower, doing laundry or a load of dishes. You can also use a filter certified by an American National Standards Institute accredited certifier to reduce lead in drinking water. If you are concerned about lead in your water and wish to have your water tested, contact CITY OF STOCKTON and [ADD CONTACT INFO]. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available at http://www.epa.gov/safewater/lead.

The Revised Lead and Copper Rule requires water systems to develop and maintain a Service Line Inventory. The service line is the underground pipe that supplies your home or building with water. To view the Service Line Inventory, which lists the material type(s) for your location, you may view the inventory at: [Insert a direct link to the website or physical location/address where the inventory is publicly accessible to be viewed].

Chlorine/Chloramines Maximum Disinfection Level MPA MPA Units RAA RAA Units

2024 - 2024 1.6000 MG/L 1.3 MG/L

Please Note: Because of sampling schedules, results may be older than 1 year.

During the 2024 calendar year, we had the below noted violation(s) of drinking water regulations.

Regulated Contaminants Collection Date Highest Value Range (low/high) Unit MCL MCLG Typical Source

ARSENIC 4/17/2024 6.1 6.1 ppb 10 0 Erosion of natural deposits

BARIUM 4/17/2024 0.019 0.019 ppm 2 2 Discharge from metal refineries

FLUORIDE 10/9/2024 0.42 0.25 - 0.42 ppm 4 4 Natural deposits; Water additive which promotes strong teeth.

NITRATE 4/17/2024 1.9 1.6 - 1.9 ppm 10 10 Runoff from fertilizer use

SELENIUM 4/17/2024 4.6 4.6 ppb 50 50 Erosion of natural deposits

Secondary Contaminants – Non-Health Based Contaminants - No Federal Maximum Contaminant Level (MCL) Established. Collection Date Highest Value Range (low/high) Unit SMCL

ALKALINITY, TOTAL 4/17/2024 280 280 MG/L 300

CALCIUM 4/17/2024 110 110 MG/L 200

CHLORIDE 4/17/2024 200 200 MG/L 250

CONDUCTIVITY @ 25 C UMHOS/CM 4/17/2024 2100 2100 UMHO/CM 1500

HARDNESS, TOTAL (AS CACO3) 4/17/2024 410 410 MG/L 400

MAGNESIUM 4/17/2024 36 36 MG/L 150

MANGANESE 4/17/2024 0.0027 0.0027 MG/L 0.05

NICKEL 4/17/2024 0.0032 0.0032 MG/L 0.1

PH 4/19/2021 7.7 7.7 PH 8.5

PHOSPHORUS, TOTAL 4/17/2024 1 1 MG/L 5

POTASSIUM 4/17/2024 13 13 MG/L 100

SILICA 4/17/2024 31 31 MG/L 50

SODIUM 4/17/2024 360 360 MG/L 100

SULFATE 4/17/2024 580 580 MG/L 250

TDS 4/17/2024 1500 1500 MG/L 500

ZINC 4/17/2024 1.3 1.3 MG/L 5

Additional Required Health Effects Language:

While your drinking water meets EPA's standard for arsenic, it does contain low levels of arsenic. EPA's standard balances the current understanding of arsenic's possible health effects against the costs of removing arsenic from drinking water. EPA continues to research the health effects of low levels of arsenic which is a mineral known to cause cancer in humans at high concentrations and is linked to other health effects such as skin damage and circulatory problems.