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Is Antioch Tap Water Safe to Drink?

Yes! Generally Safe to Drink*

LAST UPDATED: 5:08 am, December 12, 2021
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Table of Contents

Can You Drink Tap Water in Antioch?

Yes, Antioch's tap water is generally considered safe to drink as Antioch has no active health based violations of the Safe Drinking Water Act (SDWA) that we are aware of. Other factors such as lead piping in a home, or low levels of pollutants on immunocompromised individuals, should also be considered, however. For the latest updates on Antioch water, please check out its Twitter page

According the EPA’s ECHO database, from Oct. 31, 2018 to Dec. 31, 2021, Antioch's water utility, City of Antioch, had 0 violations of the Safe Drinking Water Act. For more details on the violations, please see our violation history section below. This assessment is based on the City of Antioch water system, other water systems in the city may have different results.

While tap water that meets the EPA health guidelines generally won’t make you sick to your stomach, it can still contain regulated and unregulated contaminants present in trace amounts that could potentially cause health issues over the long-run. These trace contaminants may also impact immunocompromised and vulnerable individuals.

The EPA is reviewing if it’s current regulations around pollutant levels in tap water are strict enough, and the health dangers posed by unregulated pollutants, like PFAS.

Water Quality Report for Antioch Tap Water

The most recent publicly available numbers for measured contaminant levels in Antioch tap water are in its 2020 Water Quality Report. As you can see, there are levels which the EPA considers to be acceptable, but being below the maximum allowable level doesn’t necessarily mean the water is healthy.

Lead in tap water, for example, is currently allowed at up to 15ppb by the EPA, but it has set the ideal goal for lead at zero. This highlights how meeting EPA standards doesn’t necessarily mean local tap water is healthy.

EPA regulations continue to change as it evaluates the long term impacts of chemicals and updates drinking water acceptable levels. The rules around arsenic, as well as, lead and copper are currently being re-evaluated.

There are also a number of "emerging" contaminants that are not currently. For example, PFAS (Per- and polyfluoroalkyl substances), for which the EPA has issued a health advisory. PFAS are called "forever chemicals" since they tend not to break down in the environment or the human body and can accumulate over time.

We recommend looking at the contaminants present in Antioch's water quality reports, or getting your home's tap water tested to see if you should be filtering your water.

Antioch Tap Water Safe Drinking Water Act Violation History - Prior 10 Years

Below is a ten year history of violations for the water system named City of Antioch for Antioch in California. For more details please see the "What do these Violations Mean?" section below.

Is there Lead in Antioch Water?

Based on the EPA’s ECHO Database, 90% of the samples taken from the Antioch water system, City of Antioch, between sample start date and sample end date, were at or below, 0.0 mg/L of lead in Antioch water. This is 0% of the 0.015 mg/L action level. This means 10% of the samples taken from Antioch contained more lead.

While Antioch water testing may have found 0.0 mg/L of lead in its water, that does not mean your water source has the same amount. The amount of lead in water in a city can vary greatly from neighborhood to neighborhood, or even building to building. Many buildings, particularly older ones, have lead pipes or service lines which can be a source of contamination. To find out if your home has lead, we recommend getting you water tested.

No amount of lead in water is healthy, only less dangerous. As lead accumulates in our bodies over time, even exposure to relatively small amounts can have negative health effects. For more information, please check out our Lead FAQ page.

Are there PFAS in Antioch Tap Water?

Currently, testing tap water for PFAS isn’t mandated on a national level. We do have a list of military bases where there have been suspected or confirmed leaks. There appears to be at least one military base - Rio Vista - near Antioch with suspected leaks.

With many potential sources of PFAS in tap water across the US, the best information we currently have about which cities have PFAS in their water is this ewg map, which you can check to see if Antioch has been evaluated for yet.

Our stance is better safe than sorry, and that it makes sense to try to purify the tap water just in case.

What do these Violations Mean?

Safe Drinking Water Act Violations categories split into two groups, health based, and non-health based. Generally, health based violations are more serious, though non-health based violations can also be cause for concern.

Health Based Violations

  1. Maximum contaminant levels (MCLs) - maximum allowed contaminant level was exceeded.
  2. Maximum residual disinfectant levels (MRDLs) - maximum allowed disinfectant level was exceeded.
  3. Other violations (Other) - the exact required process to reduce the amounts of contaminants in drinking water was not followed.

Non-Health Based Violations

  1. Monitoring and reporting violations (MR, MON) - failure to conduct the required regular monitoring of drinking water quality, and/or to submit monitoring results on time.
  2. Public notice violations (Other) - failure to immediately alert consumers if there is a serious problem with their drinking water that may pose a risk to public health.
  3. Other violations (Other) - miscellaneous violations, such as failure to issue annual consumer confidence reports or maintain required records.

SDWA Table Key

Field Description
Compliance Period Dates of the compliance period.
Status Current status of the violation.
  • Resolved - The violation has at least one resolving enforcement action. In SDWIS, this indicates that either the system has returned to compliance from the violation, the rule that was violated was no longer applicable, or no further action was needed.
  • Archived - The violation is not Resolved, but is more than five years past its compliance period end date. In keeping with the Enforcement Response Policy, the violation no longer contributes to the public water system's overall compliance status. Unresolved violations are also marked as Archived when a system ceases operations (becomes inactive).
  • Addressed - The violation is not Resolved or Archived, and is addressed by one or more formal enforcement actions.
  • Unaddressed - The violation is not Resolved or Archived, and has not been addressed by formal enforcement.
show details
Health-Based? Whether the violation is health based.
Category Code
The category of violation that is reported.
  • TT - Treatment Technique Violation
  • MRDL - Maximum Residual Disinfectant Level
  • Other - Other Violation
  • MCL - Maximum Contaminant Level Violation
  • MR - Monitoring and Reporting
  • MON - Monitoring Violation
  • RPT - Reporting Violation
show details
Code A full description of violation codes can be accessed in the SDWA_REF_CODE_VALUES (CSV) table.
Contaminant Code A code value that represents a contaminant for which a public water system has incurred a violation of a primary drinking water regulation.
Rule Code Code for a National Drinking Water rule.
  • 110 - Total Coliform Rule
  • 121 - Surface Water Treatment Rule
  • 122 - Long Term 1 Enhanced Surface Water Treatment Rule
  • 123 - Long Term 2 Enhanced Surface Water Treatment Rule
  • 130 - Filter Backwash Rule
  • 140 - Ground Water Rule
  • 210 - Stage 1 Disinfectants and Disinfection Byproducts Rule
  • 220 - Stage 2 Disinfectants and Disinfection Byproducts Rule
  • 230 - Total Trihalomethanes
  • 310 - Volatile Organic Chemicals
  • 331 - Nitrates
  • 332 - Arsenic
  • 333 - Inorganic Chemicals
  • 320 - Synthetic Organic Chemicals
  • 340 - Radionuclides
  • 350 - Lead and Copper Rule
  • 410 - Public Notice Rule
  • 420 - Consumer Confidence Rule
  • 430 - Miscellaneous
  • 500 - Not Regulated
  • 111 - Revised Total Coliform Rule
show details
Rule Group Code Code that uniquely identifies a rule group.
  • 120 - Surface Water Treatment Rules
  • 130 - Filter Backwash Rule
  • 140 - Groundwater Rule
  • 210 - Stage 1 Disinfectants and Disinfection Byproducts Rule
  • 220 - Stage 2 Disinfectants and Disinfection Byproducts Rule
  • 230 - Total Trihalomethanes
  • 310 - Volatile Organic Chemicals
  • 320 - Synthetic Organic Chemicals
  • 330 - Inorganic Chemicals
  • 340 - Radionuclides
  • 350 - Lead and Copper Rule
  • 400 - Other
  • 500 - Not Regulated
  • 110 - Total Coliform Rules
  • 410 - Public Notice Rule
  • 420 - Consumer Confidence Rule
  • 430 - Miscellaneous
show details
Rule Family Code Code for rule family.
  • 100 - Microbials
  • 200 - Disinfectants and Disinfection Byproducts Rule
  • 300 - Chemicals
  • 400 - Other
  • 500 - Not Regulated
show details

For more clarification please visit the EPA's data dictionary.

Antioch Water - Frequently Asked Questions

HOW TO READ THE TABLES
The following tables contain detailed information about the water that is delivered to your home or business. Your water is regularly tested for more than 120 chemicals and substances, as well as radioactivity. Only those constituents that were detected in 2020 are listed in the tables. Constituents may vary from provider to provider depending on water source and treatment techniques. Please see ccwater.com for a list of constituents tested but not detected. WATER PROVIDER PRIMARY DRINKING WATER STANDARDS Contaminants that may affect health
HOW DO I CONTACT ANTIOCH CUSTOMER SERVICE?
To contact customer service for the Antioch water provider, City of Antioch, please use the information below.
By Phone: 925-779-7029
By Email: mtaylor@antiochca.gov
By Mail: PO BOX 5007
ANTIOCH, CA, 94531-5007
HOW TO PAY BILL FOR CITY OF ANTIOCH
Already have an account?

Existing customers can login to their City of Antioch account to pay their Antioch water bill by clicking here.

Want to create a new account?

If you want to pay your City of Antioch bill online and haven't made an account yet, you can create an account online. Please click here to create your account to pay your Antioch water bill.

Want to pay without an account?

If you don't want to make an account, or can't remember your account, you can make a one-time payment towards your Antioch water bill without creating an account using a one time payment portal with your account number and credit or debit card. Click here to make a one time payment.

HOW TO START & STOP ANTIOCH WATER SERVICE
Starting Your Service

Moving to a new house or apartment in Antioch means you will often need to put the water in your name with City of Antioch. In order to put the water in your name, please click the link to the start service form below. Start service requests for water bills typically take two business days.

Start Service Form

Want to create a new account?

Leaving your house or apartment in Antioch means you will likely need to take your name off of the water bill with City of Antioch. In order to take your name off the water bill, please click the link to the stop service form below. Stop service for water bills requests typically take two business days.

Stop Service Form

The estimated price of bottled water

$2.33 in USD (1.5-liter)

USER SUBMITTED RATINGS

Antioch tap water
  • Drinking Water Pollution and Inaccessibility 30% Low
  • Water Pollution 40% Moderate
  • Drinking Water Quality and Accessibility 70% High
  • Water Quality 60% High

The above data is comprised of subjective, user submitted opinions about the water quality and pollution in Antioch, measured on a scale from 0% (lowest) to 100% (highest).

Related FAQS

Antioch Water Quality Report (Consumer Confidence Report)

The EPA mandates that towns and cities consistently monitor and test their tap water. They must report their findings in an annual Consumer Confidence Report. Below is the most recent water quality report from Antioch's Water. If you would like to see the original version of the report, please click here.

YOUR

DRINKING

WATER

IN 2020

ANNUAL WATER

QUALITY REPORT

CONTRA COSTA WATER DISTRICT

Erin Gomez | 925-688-8091

CITY OF ANTICOH

Laura Villasana | 925-779-7024

CITY OF MARTINEZ

Hiren Patel | 925-372-3588

CITY OF PITTSBURG

Ana Corti | 925-252-6916

DIABLO WATER DISTRICT

Nacho Mendoza | 925-625-2112

GOLDEN STATE WATER COMPANY (BAY POINT)

800-999-4033

CITY OF BRENTWOOD

James Wolfe | 925-516-6000

TO OUR CUSTOMERS:

We are pleased to present the Annual Water Quality Report that shows the high quality of your drinking water. As the water providers to more than 500,000 people, you can count on us to provide a reliable product that exceeds all drinking water standards set by the state and federal governments keeping our community healthy and thriving. We wisely put your water dollars to work investing in the systems and infrastructure that deliver a reliable supply of high-quality water at the lowest cost possible. This report includes water quality data collected throughout 2020 and answers questions you might have about your tap water. For detailed test results, see pages 7-11.

You can be confident your tap water is of a high quality that is always there for you. Frequent testing for water quality and regular improvements in the treatment process keeps your drinking water among the best in the country.

We hope you find this report useful in illustrating the high quality of your water service. If you have questions about the tap water in your community, please use the list on the left to call your water provider.

SAFETY STANDARDS ENSURE QUALITY

The sources of drinking water (both tap water and bottled water) include 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 SOURCE WATER

Microbial contaminants include viruses and bacteria, that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.

Inorganic contaminants include salts and metals that can be naturally-occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining or farming.

Organic chemical contaminants include synthetic and volatile organic chemicals that are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, agricultural application and septic systems.

Pesticides and herbicides may come from a variety of sources, such as agriculture, urban stormwater runoff and residential uses.

Radioactive contaminants can be naturally occurring or be the result of oil and gas production and mining activities.

In order to ensure that tap water is safe to drink, the U.S. Environmental Protection Agency (US EPA) and the State Water Resources Control Board (State Board) prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. State Board regulations also establish limits for contaminants in bottled water that provide the same protection for public health.

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 US EPA’s Safe Drinking Water Hotline (1-800-426-4791).

None of the public water systems listed in this report produce or distribute bottled water. The State Division of Drinking Water mandates that the statements about bottled water be included in this report.

Your drinking water is continually sampled and analyzed. We perform tens of thousands of tests throughout the year to ensure your water is clean and safe to use.

IMPORTANT NOTICE

Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno- compromised persons such as persons 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. USEPA/Centers for Disease Control (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 at 1-800-426-4791.

2 2020 ANNUAL WATER QUALITY REPORT

WATER QUALITY NOTIFICATIONS

LEAD IN DRINKING WATER

No water provider included in this report detected lead above the regulatory action level in their water supply. If present, elevated levels of 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 plumbing in buildings and homes. Your drinking water supplier is responsible for providing high quality drinking water, but cannot control the variety of materials used in plumbing components. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to two minutes before using water for drinking or cooking. If you do so, you may wish to collect the flushed water and reuse it for another beneficial purpose, such as watering plants. If you are concerned about lead in your water, you may wish to have your water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline at 1-800-426-4791 or at epa.gov/lead.

LEAD MONITORING IN SCHOOLS

In early 2017, the State Board issued amendments to domestic water supply permits of community water systems so that kindergarten through 12th grade (K–12) schools can request assistance from their water provider to conduct water sampling for lead and receive technical assistance if an elevated lead sample is found. To further safeguard water quality in California’s K–12 public schools, California Assembly Bill 746, effective January 1, 2018, requires community water systems to test lead levels, by July 1, 2019, in drinking water at all California public K–12 schools, preschools, and child care facilities located on public school property constructed before January 1, 2010.

To find out more about the Lead Sampling of Drinking Water in Schools initiative, visit waterboards.ca.gov/drinking_water/ certlic/drinkingwater/leadsamplinginschools.shtml.

The use of ozone disinfection results in drinking water that is very safe, with little taste and odor. Ozone effectively destroys potentially harmful microorganisms and, by breaking up the organic material often found in water, vastly improves the taste and odor of drinking water. In addition, ozone disinfection reduces the formation of many disinfection byproducts, such as trihalomethanes, a class of suspected cancer-causing compounds associated with chlorine disinfection.

FLUORIDE

To prevent tooth decay, fluoride is added to your drinking water. This is a long-standing practice that has improved public health over many years. To read about fluoridation, visit waterboards.ca.gov/drinking_water/certlic/drinkingwater/ Fluoridation.shtml.

Sedimentation basins in our water

treatment plants skim clean water from the top of the basin and allow heavy

organics to settle out at the bottom.

CRYPTOSPORIDIUM

Cryptosporidium is a microbial pathogen found in surface water throughout the U.S.

Although filtration removes Cryptosporidium, the most commonly-used filtration methods cannot

guarantee 100 percent removal. Our monitoring indicates the presence of these organisms in our source

water and/or finished water. Current test methods do not allow us to determine if the organisms are dead or if they are capable of causing disease. Ingestion of Cryptosporidium may

cause cryptosporidiosis, an abdominal infection. Symptoms of infection include nausea, diarrhea, and abdominal cramps. Most healthy individuals can overcome the disease within a few weeks. However, immunocompromised people, infants and small children, and the elderly are at greater risk of developing life-threatening illness. We encourage immuno-compromised individuals to consult their doctor regarding appropriate precautions to take to avoid infection. Cryptosporidium must be ingested to cause disease, and it may be spread through means other than drinking water.

2020 ANNUAL WATER QUALITY REPORT 3

THE SOURCE OF YOUR WATER

Nearly every drop of water delivered by Contra Costa Water District originates in the Sacramento-San Joaquin River Delta. Though Delta water quality fluctuates throughout the year, investments made by your water provider ensures the water delivered to your tap is of a consistent high-quality. Contra Costa Water District diverts water from four locations in the Delta and adjusts its operations to divert where water quality is best.

CONTRA COSTA WATER DISTRICT

CCWD provides treated drinking water to homes and businesses in Clayton, Clyde, Concord, Pacheco, Port Costa, and parts of Martinez, Pleasant Hill and Walnut Creek. Water is pumped from the Delta, treated and then delivered to customers through a network of distribution pipes.

CCWD completes watershed sanitary surveys every five years and the last one was completed in 2020. The surveys concluded that potential contamination is regularly mitigated by the natural flushing of the Delta, controls at contamination sources and existing water treatment practices.

In June 2002 and May 2003, source water assessments were conducted at the Old River, Rock Slough and Mallard Slough intakes, the Los Vaqueros, Contra Loma, Mallard and Martinez reservoirs, and the Contra Costa Canal at Clyde. A source water assessment was conducted for the Middle River Intake in 2012.

The assessments were based on a review of data collected from 1996 through 2001, as well as a review of the activities and facilities located at or near each source. In summary:

  • Intakes were found to be most vulnerable to the effects of saltwater intrusion, agricultural drainage, recreational boating and regulated point discharges.
  • Reservoirs were found to be most vulnerable to the effects of associated recreation, roads and parking lots, and watershed runoff.
  • Contra Costa Canal was found to be most vulnerable to gas stations, chemical/petroleum processing/storage, septic systems, historic landfills and military institutions.

BAY POINT

The Golden State Water Company (GSWC) purchases treated water from CCWD and delivers it to customers through its distribution pipes. Water quality information for GSWC is not included in this report. View its water quality report at gswater.com/baypointccr.

BRENTWOOD

CCWD operates the CCWD/City of Brentwood’s water treatment plant to treat water for the City. Water quality information for Brentwood is not included in this report. View its water quality report at brentwoodca.gov/gov/pw/water/reports.asp.

 

 

 

 

 

 

 

 

 

 

 

 

HONKER

680

 

 

 

 

 

 

 

 

 

 

 

BAY

 

 

 

SUISUN BAY

780

 

 

 

 

Port

 

 

Port

 

 

 

 

 

 

 

 

 

 

Chicago

 

 

 

 

 

 

 

 

Costa

 

 

 

 

 

 

 

 

 

 

MALLARD

 

 

 

 

Avon

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SLOUGH INTAKE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Clyde

 

 

 

 

GSWC

 

 

 

680

MALLARD

4

 

 

 

 

 

MARTINEZ

 

RESERVOIR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

RESERVOIR

 

Ralph D. Bollman

 

 

 

 

 

 

 

 

 

 

 

 

WTP

 

 

 

 

 

 

 

 

 

 

 

 

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District

 

 

 

 

 

 

 

 

 

 

 

Pacheco

 

Center

 

 

 

 

 

 

 

 

 

MARTINEZ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Concord

 

 

CCWD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TREATED WATER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pleasant

 

SERVICE AREA

 

 

 

 

 

 

 

 

 

 

Hill

 

 

 

 

 

 

 

 

 

 

 

 

 

680

 

 

 

 

 

 

 

Clayton

Walnut Creek

24

680

Contra Costa Water District Boundary

Contra Costa Canal

Multi-Purpose Pipeline

Los Vaqueros Pipeline

Shortcut Pipeline

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SA N JO

 

 

 

 

PITTSBURG

160 DIABLO

4WATER DISTRICT

 

 

 

 

Oakley

 

ANTIOCH

 

 

 

 

Randall-Bold

 

 

 

 

WTP

CONTRA

 

 

 

CCWD/

ANTIOCH

 

City of Brentwood

LOMA

 

RESERVOIR

RESERVOIR

4

WTP

 

CCWD-EBMUD

 

 

Intertie

 

 

 

BRENTWOOD

 

 

 

4

 

 

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Facility

LOS

VAQUEROS

RESERVOIR

DELTA

ROCK

SLOUGH

INTAKE

Discovery

Bay

4

OLD RIVER

MIDDLE

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J4CLIFTON

COURT

FOREBAY

4 2020 ANNUAL WATER QUALITY REPORT

YOUR WATER IS SAFE AND RELIABLE

INVESTMENTS IN

INFRASTRUCTURE

We’ve recently replaced the concrete liner along several sections of the 48-mile Contra Costa Canal. The Contra Costa Canal is the backbone of our water system, delivering water to treatment plants, businesses, and agriculture.

In addition to ensuring safe, clean water at your

tap, it’s our responsibility to maintain and upgrade the facilities that move the water throughout our communities. Every year, we invest in infrastructure upgrades like pipeline replacement, Contra Costa Canal rehabilitation, storage tank improvements, and much more to avoid costly and disruptive breaks in our system.

To learn more about planned capital improvements, visit ccwater.com/

ArchiveCenter/ViewFile/Item/323

THE FACTS ABOUT PFAS

PFAS—short for per- and polyfluoroalkyl substances—are a group of man-made

chemicals that includes perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS) and GenX chemicals. Since the 1940s, PFAS have been manufactured and used in a variety

of industries around the globe, including in the United States. The chemicals have been used in consumer products such as carpets, clothing, fabrics for furniture, paper packaging for food, and other materials (e.g., cookware) designed to be waterproof, stain-resistant, or non-stick. They also have been used in fire-retarding foam at airfields, military bases, and various industrial processes. PFOA and PFOS have been the most extensively produced and studied of these chemicals. Both are very persistent in the environment and in the human body. Exposure to certain PFAS can lead to adverse human health effects. Unfortunately, some of these substances don’t break down over time. That means they build up in the environment and in our bodies.

Testing has confirmed that CCWD’s water supply is safe to drink and PFOA/PFOS were not detected during monitoring.

To learn more about PFAS and drinking water, visit ccwater.com/422.

SAFE FROM COVID-19

Existing filtration and disinfection processes in our water treatment systems remove and kill viruses including the coronavirus. While water quality was unaffected by this new virus in our community, operations were adjusted to ensure the skilled workforce that treats, operates, and maintains remained healthy and able to keep your public water system functioning.

Coronavirus does not pose a threat to the water you depend on for drinking, bathing, washing, and so much more.

Additional information about coronavirus and drinking water is available at

epa.gov/coronavirus/coronavirus-and-drinking-water-and-wastewater.

2020 ANNUAL WATER QUALITY REPORT 5

DEFINITIONS & ABBREVIATIONS

Action Level (AL) – The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow

Maximum Contaminant Level (MCL) – The highest level of a contaminant that is allowed in drinking water. Primary MCLs are set as close to the PHGs (or MCLGs) as is economically or technologically feasible

Maximum Contaminant Level Goal (MCLG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by the U.S. Environmental Protection Agency

Maximum Residual Disinfectant Level (MRDL)

The highest level of a disinfectant allowed in drinking water. There is convincing evidence that the addition of a disinfectant is necessary for control of microbial contaminants

Maximum Residual Disinfectant Level Goal (MRDLG) – The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants

mg/L – Milligrams per liter

n/a – Not analyzed or not applicable (when used in average column, only one data point is available)

ND – Not detected at or above the reporting level ng/L – Nanograms per liter

NTU – Nephelometric turbidity units

Primary Drinking Water Standards – MCLs and MRDLs for contaminants that affect health along with their monitoring and reporting requirements, and water treatment requirements

pCi/L – Picocuries per liter (a measure of radioactivity)

Public Health Goal (PHG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. PHGs are set by the California Environmental Protection Agency Office of Health and Hazard Assessment

RAA – Running Annual Average

Secondary Drinking Water Standards – Secondary MCLs are set for contaminants that affect the odor, taste or appearance of water

Treatment Technique (TT) – A required process intended to reduce the level of a contaminant in drinking water

µg/L – Micrograms per liter

µmhos/cm– micromhos per centimeter (a measure of conductivity)

HOW TO READ THE TABLES

The following tables contain detailed information about the water that is delivered to your home or business. Your water is regularly tested for more than 120 chemicals and substances, as well as radioactivity. Only those constituents that were detected in 2020 are listed in the tables.

Constituents may vary from provider to provider depending on water source and treatment techniques. Please see ccwater.com for a list of constituents tested but not detected.

WATER

PROVIDER

PRIMARY DRINKING WATER STANDARDS Contaminants that may affect health

 

State

Highest

Range

 

 

4

Inorganic

or

Average

Major Source in Drinking Water

Amount

Federal

Detected

 

Allowed

 

 

 

Goal

 

 

 

 

 

 

1

2

 

3

Erosion of natural deposits; water

 

 

 

 

 

Fluoride (mg/L)

1

2

0.5–1.0

0.8

additive that promotes strong

 

teeth; discharge from fertilizer and

 

 

 

 

 

 

 

 

 

 

aluminum factories

 

 

 

 

 

 

 

 

  1. State or Federal Goal (PHG, MCLG or MRDLG) – The level of contaminant in drinking water below which there is no known or expected risk to health
  2. Highest Amount Allowed (AL, MCL or MRDL) – The highest level of a contaminant that is allowed in drinking water
  3. Average – The average level of a detected contaminant in drinking water
  4. Major Source in Drinking Water – The most likely way a contaminant enters drinking water

UNITS

EQUIVALENCE

 

 

mg/L (milligrams per liter)

1 second in 11.5 days

ppm (parts per million)

 

 

 

µg/L (micrograms per liter)

1 second in nearly 32 years

ppb (parts per billion)

 

 

 

6 2020 ANNUAL WATER QUALITY REPORT

CONTRA COSTA WATER DISTRICT

TABLE OF CHEMICALS OR CONSTITUENTS DETECTED IN WATER IN 2020

 

 

 

CCWD

RANDALL-BOLD

CCWD-

 

 

 

 

WTP*

BRENTWOOD WTP

 

 

 

 

 

 

 

PRIMARY DRINKING WATER STANDARDS

Contaminants that may affect health

 

 

 

Inorganic

State or

Highest Amt.

Range

Average

Range

Average

Range

Average

Major Source in Drinking Water

Federal Goal

Allowed

Detected

Detected

Detected

Fluoride (mg/L)

1

2

0.6–0.8

0.7

0.6–0.7

0.7

ND–0.1

ND

Erosion of natural deposits; water additive that promotes

strong teeth

 

 

 

 

 

 

 

 

 

Nitrate as N (mg/L)

10

10

ND–0.5

0.1

ND–0.7

0.4

ND–0.4

0.1

Runoff and leaching from fertilizer use

Lead and Copper

State or

Highest Amt.

# of Sites

90%

# of Sites

90%

# of Sites

90%

 

Tested/#

Tested/#

Tested/#

Major Source in Drinking Water

Federal Goal

Allowed

Percentile

Percentile

Percentile

 

Exceeding AL

Exceeding AL

Exceeding AL

 

 

 

 

 

 

 

 

Lead (µg/L)

0.2

15

55/0

ND

n/a

n/a

n/a

n/a

Internal corrosion of household water plumbing systems; discharges

from industrial manufacturers; erosion of natural deposits

 

 

 

 

 

 

 

 

 

Copper (mg/L)

0.3

1.3

55/0

0.14

n/a

n/a

n/a

n/a

Internal corrosion of household water plumbing systems;

erosion of natural deposits; leaching from wood preservatives

 

 

 

 

 

 

 

 

 

Date of sampling

 

 

June 2019

n/a

n/a

 

Microbiological

State or

Highest Amt.

Maximum

Average or

Maximum

Average or

Maximum

Average or

 

[Monthly % of

[Monthly % of

[Monthly % of

Major Source in Drinking Water

Standards

Federal Goal

Allowed

Value

Samples that Meets

Value

Samples that Meets

Value

Samples that Meets

 

 

 

 

Requirement]

 

Requirement]

 

Requirement]

 

Total Coliform

n/a

5% of mo.

0%–1.1%

0.3%

n/a

n/a

n/a

n/a

Naturally present in the environment

(state Total Coliform Rule)

 

samples

 

 

 

 

 

 

 

Turbidity (NTU)

n/a

95% ≤ 0.3

0.22

[100%]

0.10

[100%]

0.14

[100%]

Soil runoff

(treatment plant)

 

 

 

 

 

 

 

 

 

Disinfectant/Disin-

State or

Highest Amt.

Range

Highest

Range

Highest

Range

Highest

 

Quarterly

Quarterly

Quarterly

Major Source in Drinking Water

fection Byproducts

Federal Goal

Allowed

Detected

Detected

Detected

RAA

RAA

RAA

 

Bromate (µg/L)

0.1

10

ND–9.6

ND

n/a

n/a

n/a

n/a

Disinfectant/Disinfection Byproducts

Chloramines as CI2 (mg/L)

 

4

ND–3.6

1.7

n/a

n/a

n/a

n/a

Disinfectant/Disinfection Byproducts

Haloacetic acids (µg/L)

n/a

60

1.7–18

12

n/a

n/a

n/a

n/a

Byproduct of drinking water disinfection

Total trihalomethanes

n/a

80

7.4–28

20

n/a

n/a

n/a

n/a

Byproduct of drinking water disinfection

(µg/L)

 

 

 

 

 

 

 

 

 

SECONDARY DRINKING WATER STANDARDS Contaminants that may affect the odor, taste or appearance of water

 

State or

Highest Amt.

Range

Average

Range

Average

Range

Average

Major Source in Drinking Water

 

Federal Goal

Allowed

Detected

Detected

Detected

 

 

 

 

 

Chloride (mg/L)

n/a

250

33–84

58

32–83

58

31–149

68

Runoff/leaching from natural deposits; seawater influence

Specific conductivity

n/a

900

312–553

437

336–577

466

309–750

473

Substances that form ions when in water; seawater influence

(µmhos/cm)

 

 

 

 

 

 

 

 

 

Sulfate (mg/L)

n/a

250

36–53

49

49–85

62

36–71

54

Naturally-occurring organic materials

Total dissolved solids

n/a

500

164–292

231

181–312

248

165–394

252

Runoff/leaching from natural deposits

(mg/L)

 

 

 

 

 

 

 

 

 

Turbidity (NTU)

n/a

5

0.08–0.51

0.20

n/a

n/a

n/a

n/a

Soil runoff

(distribution system)

 

 

 

 

 

 

 

 

 

GENERAL WATER QUALITY PARAMETERS Non-regulated parameters of general interest to consumers

 

 

State or

Highest Amt.

Range

Average

Range

Average

Range

Average

PUBLIC MEETINGS

 

Federal Goal

Allowed

Detected

Detected

Detected

 

 

 

 

 

 

 

Alkalinity (mg/L)

n/a

n/a

54–82

69

51–90

65

55–71

66

First and Third Wednesday

Ammonia (mg/L)

n/a

n/a

0.6

n/a

0.5

n/a

0.5

n/a

6:30 p.m.

Bromide (mg/L)

n/a

n/a

ND–0.2

0.1

ND–0.2

0.1

ND–0.3

0.1

Calcium (mg/L)

n/a

n/a

12–22

16

12–25

17

13–19

16

1331 Concord Avenue

Hardness (mg/L)

n/a

n/a

65–110

85

64–120

89

64–110

88

Concord, CA 94520

Magnesium (mg/L)

n/a

n/a

8.2–13

11

8.2–14

11

8.5–17

12

925-688-8000

pH

n/a

n/a

8.1–8.8

8.4

7.8–8.7

8.2

8.0–9.1

8.4

 

 

 

 

 

 

 

 

 

ccwater.com

Potassium (mg/L)

n/a

n/a

1.9–3.2

2.5

1.8–3.3

2.5

2.1–4.2

2.6

Sodium (mg/L)

n/a

n/a

34–66

52

39–74

55

35–110

58

 

UCMR4 ASSESSMENT MONITORING 2018–2020

 

 

 

 

 

In-person attendance subject

 

Federal Goal

Level

Detected

Average

Detected

Average

Detected

Average

to COVID-19 restrictions. For

 

State or

Notification

Range

 

Range

 

Range

 

 

 

 

 

 

 

 

 

 

 

teleconference information, visit

Manganese (µg/L)

n/a

500

1.2–6.8

3.6

0.9–45

12

1.8–4.1

3.2

HAA5 (µg/L)

n/a

n/a

1.6–14

6.6

n/a

n/a

n/a

n/a

ccwater.com.

HAA Br (µg/L)

n/a

n/a

1.4–15

7.1

n/a

n/a

n/a

n/a

 

HAA9 (µg/L)

n/a

n/a

2.5–25

11

n/a

n/a

n/a

n/a

If you have any questions about Contra

Total Organic Carbon

n/a

n/a

2,800–

3,475

2,000–

3000

2,100–

3,525

Costa Water District tap water, please

(TOC) (µg/L)

4,200

4,300

5400

 

 

 

 

 

 

 

 

 

call 925-688-8091.

Bromide (µg/L)

n/a

n/a

110–236

189

88-275

191

89-262

176

 

 

*Randall-Bold Water Treatment Plant is a regular source of water for CCWD, Diablo Water District and the Golden State Water Company in Bay Point. It is also an as-needed source of water for Antioch and Brentwood and an emergency source for Pittsburg.

2020 ANNUAL WATER QUALITY REPORT 7

CITY OF ANTIOCH

SOURCE OF WATER

The City of Antioch purchases untreated water from CCWD, treats it in

a City-owned treatment

TABLE OF CHEMICALS OR CONSTITUENTS DETECTED IN WATER IN 2020

CITY OF

ANTIOCH

PRIMARY DRINKING WATER STANDARDS Contaminants that may affect health

plant and delivers it to customers through the City’s distribution pipes. The City is also able to pump directly from the San Joaquin River or purchase treated water from CCWD.

The City completes watershed sanitary surveys every five years. The last survey, completed in 2018, concluded that potential contamination is regularly mitigated by the natural flushing of the Delta, controls at contamination

Inorganic

Fluoride (mg/L)

Lead and Copper

Lead (µg/L)

Copper (mg/L)

Date of sampling

Microbiological Standards

Turbidity (NTU) (treatment plant)

Disinfectant/Disinfection Byproducts

Chloramines as CI2 (mg/L)

Haloacetic acids (µg/L)

Total trihalomethanes (µg/L)

State or

Federal Goal

1

State or

Federal Goal

0.2

0.3

State or

Federal Goal

n/a

State or

Federal Goal

n/a

n/a

Highest Amt.

Range

Average

Major Source in Drinking Water

Allowed

Detected

 

 

4

0.6–1.0

0.8

Erosion of natural deposits; water additive that

promotes strong teeth

 

 

 

 

Highest Amt.

# of Sites

90%

 

Tested/#

Major Source in Drinking Water

Allowed

 

Percentile

Exceeding AL

 

 

 

 

 

 

 

 

 

 

Internal corrosion of household water plumbing

0

50/0

< 5.0

systems; discharges from industrial manufacturers;

 

 

 

 

erosion of natural deposits

 

 

 

 

Internal corrosion of household water plumbing

1.3

50/0

0.051

systems; erosion of natural deposits; leaching from

 

 

 

 

wood preservatives

 

August 2018

 

Highest Amt.

Maximum

 

Monthly %

 

 

 

 

of Samples

Major Source in Drinking Water

Allowed

Value

 

that Meets

 

 

 

 

 

Requirement

 

95% ≤ 0.3

0.19

 

99%

Soil runoff

Highest Amt.

Range

 

Highest

Major Source in Drinking Water

Allowed

Detected

 

Quarterly RAA

4

0.6–3.5

 

2.4

Drinking water disinfectant added for treatment

60

2.7–12

 

8.0

Byproduct of drinking water disinfection

80

39–62

 

55

Byproduct of drinking water disinfection

 

 

 

 

 

sources and existing water

SECONDARY DRINKING WATER STANDARDS Contaminants that may affect the odor, taste or appearance of water

treatment practices.

In April 2003, Antioch conducted a source water assessment. In summary:

Antioch Municipal

Reservoir was found

to be most vulnerable

to sewer collection

Chloride (mg/L)

Odor-threshold (units)

Specific conductivity (µmhos/cm)

Sulfate (mg/L)

Total dissolved solids (mg/L)

Turbidity (NTU)

(distribution system)

State or

Federal Goal

n/a

n/a

n/a

n/a

n/a

n/a

Highest Amt.

Allowed

n/a

3

900

250

500

5

Range

Detected

31–111

1–2

336–630

48–58

142–382

0.03–0.78

Average

70

2

490

53

294

0.06

Major Source in Drinking Water

Runoff/leaching from natural deposits; seawater influence

Naturally-occurring organic materials

Substances that form ions when in water; seawater influence

Naturally-occurring organic materials

Runoff/leaching from natural deposits

Soil runoff

systems; this activity

GENERAL WATER QUALITY PARAMETERS

is not associated with

contaminants in the

water supply.

San Joaquin River

was found to be most

vulnerable to the effects

of saltwater intrusion,

Alkalinity (mg/L)

Calcium (mg/L)

Hardness (mg/L)

Magnesium (mg/L)

pH

Potassium (mg/L)

Sodium (mg/L)

State or

Federal Goal

n/a

n/a

n/a

n/a

n/a

n/a

n/a

Highest Amt.

Allowed

n/a

n/a

n/a

n/a

n/a

n/a

n/a

Range

Detected

61–109

12–34

71–128

11–12

7.9–9.4

2–3

52–65

Average

80

18

94

12

8.6

2.5

59

PUBLIC MEETINGS

Second and Fourth Tuesdays 7:00 p.m.

200 H Street Antioch, CA 94509

925-779-7009 ci.antioch.ca.us

chemical/petroleum

UCMR4 ASSESSMENT MONITORING 2018–2020

processing or storage,

and regulated point

discharges.

Water from the San Joaquin River is not always acceptable due to saltwater intrusion. When chloride levels in the river exceed 250 milligrams per liter, the City stops pumping until chloride levels decrease.

Manganese (µg/L)

HAA5 (µg/L)

HAA Br (µg/L)

HAA9 (µg/L)

Total Organic Carbon (TOC) (µg/L)

Bromide (µg/L)

State or

Federal Goal

n/a

n/a

n/a

n/a

n/a

n/a

Notification

Level

500

n/a

n/a

n/a

n/a

n/a

Range

Detected

1.0–7.8

1.7–12

0.7–12

2.4–21

2,500–

3,900

130–360

Average

3.6

4.8

5.2

8.9

3,200

238

If you have any questions about the City of Antioch tap water, please call 925-779-7024.

8 2020 ANNUAL WATER QUALITY REPORT

CITY OF MARTINEZ

TABLE OF CHEMICALS OR CONSTITUENTS DETECTED IN WATER IN 2020

CITY OF

MARTINEZ

PRIMARY DRINKING WATER STANDARDS Contaminants that may affect health

SOURCE OF WATER

The City of Martinez purchases untreated water from CCWD, treats it in a City-owned

Inorganic

Fluoride (mg/L)

Nitrate as N (mg/L)

Lead and Copper

Lead (µg/L)

Copper (mg/L)

Date of sampling

Microbiological Standards

Turbidity (NTU) (treatment plant)

Disinfectant/Disinfection Byproducts

Chloramines as CI2 (mg/L)

Haloacetic acids (µg/L)

Total trihalomethanes (µg/L)

State or

Federal Goal

1

10

State or

Federal Goal

0.2

0.3

State or

Federal Goal

n/a

State or

Federal Goal

n/a

n/a

Highest Amt.

Allowed

2

10

Highest Amt.

Allowed

15

1.3

Highest Amt.

Allowed

95% ≤ 0.3

Highest Amt.

Allowed

4

60

80

Range

Average

Major Source in Drinking Water

Detected

 

 

0.6–0.8

0.7

Erosion of natural deposits; water additive that

promotes strong teeth

 

 

ND–0.5

0.3

Runoff and leaching from fertilizer use

# of Sites

90%

 

Tested/#

Major Source in Drinking Water

Percentile

Exceeding AL

 

 

 

 

 

Internal corrosion of household water plumbing

61/0

ND

systems; discharges from industrial manufacturers;

 

 

erosion of natural deposits

 

 

Internal corrosion of household water plumbing

61/0

0.07

systems; erosion of natural deposits; leaching from

 

 

wood preservatives

June 2018

 

Maximum

Average or

 

[Monthly % of

Major Source in Drinking Water

Value

Samples that Meets

 

Requirement]

 

0.11

[100%]

Soil runoff

Range

Highest

Major Source in Drinking Water

Detected

Quarterly RAA

ND–3.5

1.7

Drinking water disinfectant added for treatment

ND–3.5

3.0

Byproduct of drinking water disinfection

8.9–23

16

Byproduct of drinking water disinfection

 

 

 

treatment plant and delivers it through the City’s distribution pipes to customers who are not served treated water directly from CCWD.

SECONDARY DRINKING WATER STANDARDS Contaminants that may affect the odor, taste or appearance of water

Chloride (mg/L)

Odor-threshold (units)

Specific conductivity (µmhos/cm)

Sulfate (mg/L)

Total dissolved solids (mg/L)

Turbidity (NTU)

(distribution system)

State or

Federal Goal

n/a

n/a

n/a

n/a

n/a

n/a

Highest Amt.

Allowed

250

3

900

250

500

5

Range

Detected

38–75

ND–1

360–490

48–51

190–290

0.2–0.4

Average

57

1

425

50

240

0.3

Major Source in Drinking Water

Runoff/leaching from natural deposits; seawater influence

Naturally-occurring organic materials

Substances that form ions when in water; seawater influence

Naturally-occurring organic materials

Runoff/leaching from natural deposits

Soil runoff

GENERAL WATER QUALITY PARAMETERS

Alkalinity (mg/L)

Bromide (mg/L)

Calcium (mg/L)

Hardness (mg/L) Magnesium (mg/L) pH

Potassium (mg/L) Sodium (mg/L)

State or

Federal Goal

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

Highest Amt.

Allowed

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

Range

Detected

63–64

0.1–0.3

14–16

72–85

9–11

8.4–9.3

1.9–3.0

43–58

Average

64

0.2

15

79

10

9.0

2.5

51

PUBLIC MEETINGS

First and Third Wednesdays 7:00 p.m.

525 Henrietta Street Martinez, CA 94553

925-372-2512 cityofmartinez.org

UCMR4 ASSESSMENT MONITORING 2018–2020

If you have any questions about

Manganese (µg/L)

HAA5 (µg/L)

HAA Br (µg/L)

HAA9 (µg/L)

Total Organic Carbon (TOC) (µg/L)

Bromide (µg/L)

State or

Federal Goal

n/a

n/a

n/a

n/a

n/a

n/a

Notification

Level

500

n/a

n/a

n/a

n/a

n/a

Range

Detected

0.4–5.0

0.3–4.4

0.6–5.1

1.0–7.1

2,800–

4,400

110–310

Average

3.1

2.4

2.7

3.8

3,667

227

the City of Martinez tap water, please call 925-372-3588.

2020 ANNUAL WATER QUALITY REPORT 9

CITY OF PITTSBURG

SOURCE OF WATER

The City of Pittsburg purchases untreated water from CCWD, treats it in

a City-owned treatment plant and delivers it to customers through the City’s distribution pipes. In addition to the water it buys from CCWD, the City is able to pump water from two wells.

A source water assessment was conducted for the Dover Well in September 2015, and for Bodega Well in July 2009. In summary:

  • Bodega well was found to be most vulnerable to residential sewer collection systems, abandoned military installation (Camp Stoneman) and illegal activities (drug labs).
  • Dover well was considered most vulnerable to sewer collection systems, transportation corridors, and storm drain discharge points. No contaminants associated with the identified potentially contaminating activities (PCA) have been detected in water samples from Dover well.

TABLE OF CHEMICALS OR CONSTITUENTS DETECTED IN WATER IN 2020

CITY OF

PITTSBURG

PRIMARY DRINKING WATER STANDARDS Contaminants that may affect health

Inorganic

State or

Highest Amt.

Range

Average

Major Source in Drinking Water

Federal Goal

Allowed

Detected

Aluminum (mg/L)

0.6

1

ND–0.1

0.05

Erosion of natural deposits; residue from some

surface water treatment processes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Arsenic (µg/L)

0.004

10

1.6–2.6

2.1

Erosion of natural deposits; runoff from orchards;

glass and electronics production wastes

 

 

 

 

 

 

Fluoride (mg/L)

1

2

0.4–0.8

0.7

Erosion of natural deposits; water additive that

promotes strong teeth

 

 

 

 

 

 

Nitrate as N (mg/L)

10

10

0.4

 

n/a

Runoff and leaching from fertilizer use

Lead and Copper

State or

Highest Amt.

# of Sites

90%

 

Tested/#

Major Source in Drinking Water

Federal Goal

Allowed

Percentile

 

Exceeding AL

 

 

 

 

 

 

 

 

 

 

 

 

Internal corrosion of household water plumbing

Lead (µg/L)

0.2

15

54/0

 

ND

systems; discharges from industrial manufacturers;

 

 

 

 

 

 

erosion of natural deposits

 

 

 

 

 

 

Internal corrosion of household water plumbing

Copper (mg/L)

0.3

1.3

54/0

 

ND

systems; erosion of natural deposits; leaching from

 

 

 

 

 

 

wood preservatives

Date of sampling

 

 

August 2018

 

 

State or

Highest Amt.

Maximum

Monthly %

 

Microbiological Standards

of Samples

Major Source in Drinking Water

Federal Goal

Allowed

Value

that Meets

 

 

 

 

 

Requirement

 

Turbidity (NTU) (treatment plant)

n/a

95% ≤ 0.3

0.16

 

100%

Soil runoff

Disinfectant/Disinfection

State or

Highest Amt.

Range

Highest

Major Source in Drinking Water

Byproducts

Federal Goal

Allowed

Detected

Quarterly RAA

Chloramines as CI2 (mg/L)

 

4

0.3–2.3

1.5

Drinking water disinfectant added for treatment

Chlorite (mg/L)

0.05

1

0.1–0.4

0.3

 

Haloacetic acids (µg/L)

n/a

60

6–11

10

Byproduct of drinking water disinfection

Total trihalomethanes (µg/L)

n/a

80

20–48

36

Byproduct of drinking water disinfection

SECONDARY DRINKING WATER STANDARDS

Contaminants that may affect the odor, taste or appearance of water

 

State or

Highest Amt.

Range

Average

Major Source in Drinking Water

 

Federal Goal

Allowed

Detected

 

 

 

Aluminum (µg/L)

n/a

200

ND–140

49

Erosion of natural deposits; residue from some

surface water treatment processes

 

 

 

 

 

 

Chloride (mg/L)

n/a

250

51–135

94

Runoff/leaching from natural deposits; seawater

influence

 

 

 

 

 

 

Odor-threshold (units)

n/a

3

1.3

 

1.3

Naturally-occurring organic materials

 

 

 

 

 

 

 

Specific conductivity

n/a

900

447–885

658

Substances that form ions when in water; seawater

(µmhos/cm)

influence

 

 

 

 

 

Sulfate (mg/L)

n/a

250

59–98

74

Naturally-occurring organic materials

Total dissolved solids (mg/L)

n/a

500

260–507

377

Runoff/leaching from natural deposits

 

 

 

 

 

 

 

Turbidity (NTU)

n/a

5

0.06–0.25

0.12

Soil runoff

(distribution system)

 

 

 

 

 

 

GENERAL WATER QUALITY PARAMETERS

 

 

 

 

 

State or

Highest Amt.

Range

Average

PUBLIC MEETINGS

 

Federal Goal

Allowed

Detected

 

 

Alkalinity (mg/L)

n/a

n/a

67–160

106

First and Third Mondays

Ammonia (mg/L)

n/a

n/a

1.2

 

n/a

Calcium (mg/L)

n/a

n/a

29

 

n/a

7:00 p.m.

Hardness (mg/L)

n/a

n/a

93–196

157

65 Civic Avenue

Magnesium (mg/L)

n/a

n/a

16

 

n/a

Pittsburg, CA 94565

pH

n/a

n/a

8.0–8.8

8.5

925-252-4850

Potassium (mg/L)

n/a

n/a

2.8

 

n/a

 

ci.pittsburg.ca.us

Sodium (mg/L)

n/a

n/a

56

 

n/a

UCMR4 ASSESSMENT MONITORING 2018–2020

 

 

 

If you have any questions about

 

State or

Notification

Range

Average

 

Federal Goal

Level

Detected

 

the City of Pittsburg tap water,

Manganese (µg/L)

n/a

500

3.2–5.3

3.9

please call 925-252-6916.

HAA5 (µg/L)

n/a

n/a

1.7–8.6

5.4

HAA Br (µg/L)

n/a

n/a

1.0–16

8.4

 

HAA9 (µg/L)

n/a

n/a

2.7–20

12

 

Total Organic Carbon (TOC)

n/a

n/a

2,100–

2,975

 

(µg/L)

4,200

 

 

 

 

 

 

 

Bromide (µg/L)

n/a

n/a

45–260

115

 

UNTREATED WATER TEST RESULTS

 

 

 

 

 

Radiochemistry

State or

Highest Amt.

Range

Average

 

Federal Goal

Allowed

Detected

 

Gross Beta (pCi/L)

0

50

4.0–6.0

5.0

 

Uranium (pCi/L)

0.43

20

1.2–1.3

1.3

 

10 2020 ANNUAL WATER QUALITY REPORT

DIABLO WATER DISTRICT

TABLE OF CHEMICALS OR CONSTITUENTS DETECTED IN WATER IN 2020

 

 

 

DIABLO WD

RANDALL-BOLD

 

 

 

 

WTP

 

 

 

 

 

 

 

PRIMARY DRINKING WATER STANDARDS Contaminants that may affect health

 

Inorganic

State or

Highest Amt.

Range

Average

Range

 

Average

Major Source in Drinking Water

Federal Goal

Allowed

Detected

Detected

 

 

 

 

 

 

 

 

 

Erosion of natural deposits;

Fluoride (mg/L)

1

2

0.6–0.7

0.7

0.6–0.7

 

0.7

water additive that promotes

 

 

 

 

 

 

 

 

strong teeth

Nitrate as N (mg/L)

10

10

0.2–0.8

0.5

ND-0.7

 

0.4

Runoff and leaching from

 

fertilizer use

 

 

 

 

 

 

 

 

Lead and Copper

State or

Highest Amt.

# of Sites

90%

# of Sites

 

90%

 

Tested/#

Tested/#

 

Major Source in Drinking Water

Federal Goal

Allowed

Percentile

 

Percentile

 

Exceeding AL

Exceeding AL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Internal corrosion of household

Lead (µg/L)

0.2

15

30/0

0.6

n/a

 

n/a

water plumbing systems; discharges

 

from industrial manufacturers;

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

erosion of natural deposits

 

 

 

 

 

 

 

 

Internal corrosion of household

Copper (mg/L)

0.3

1.3

30/0

0.14

n/a

 

n/a

water plumbing systems; erosion

 

of natural deposits; leaching

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

from wood preservatives

Date of sampling

 

 

June 2019

 

n/a

 

 

 

 

 

 

 

 

 

 

Microbiological

State or

Highest Amt.

Maximum

Monthly %

Maximum

 

Monthly %

 

of Samples

 

of Samples

Major Source in Drinking Water

Standards

Federal Goal

Allowed

Value

that Meets

Value

 

that Meets

 

 

 

 

 

 

Requirement

 

 

Requirement

 

Turbidity (NTU)

n/a

95% ≤ 0.3

n/a

n/a

0.10

 

100%

Soil runoff

(treatment plant)

 

 

 

 

 

 

 

 

 

Total Coliform

n/a

5% of mo.

0.0%–1.5%

0.1%

n/a

 

n/a

Soil runoff

(State Total Coliform Rule)

samples

 

 

 

 

 

 

 

 

Disinfectant/

State or

Highest Amt.

Range

Highest

Range

 

Highest

Major Source in Drinking Water

Disinfection Byproducts

Federal Goal

Allowed

Detected

Quarterly RAA

Detected

 

Quarterly RAA

Chloramines as CI2

 

4

0.1–3.6

2.4

n/a

 

n/a

Drinking water disinfectant

(mg/L)

 

 

 

 

 

 

 

added for treatment

Haloacetic acids (µg/L)

n/a

60

3.0–9.9

7.0

n/a

 

n/a

Byproduct of drinking water

 

disinfection

 

 

 

 

 

 

 

 

Total trihalomethanes

n/a

80

7.0–16

12

n/a

 

n/a

Byproduct of drinking water

(µg/L)

 

disinfection

 

 

 

 

 

 

 

SECONDARY DRINKING WATER STANDARDS Contaminants that may affect the odor, taste or appearance of water

SOURCE OF WATER

Diablo Water District purchases untreated water from CCWD. Water is treated and blended with groundwater pumped from two wells. The treated water is then delivered

to customers through its distributions pipes.

A source water assessment was conducted for the Glen Park well in April 2005 and for Stonecreek well in March 2011. In summary:

  • Both wells were found to be most vulnerable to historic waste dumps/ landfills and septic systems (high density, >1/acre). These activities are not associated with contaminants in the water supply.

Chloride (mg/L)

Manganese (µg/L) Specific conductivity (µmhos/cm)

Sulfate (mg/L)

Total dissolved solids (mg/L)

Turbidity (NTU)

(distribution system)

State or

Federal Goal

n/a

n/a

n/a

n/a

n/a

n/a

Highest Amt.

Allowed

250

50

900

250

500

5

Range

Detected

45–100

ND–170

433–691

47–95

229–383

0.11–0.68

Average

67

28

549

73

296

0.25

Range

Detected

32-83

ND

336–577

49–85

181–312

n/a

Average

58

n/a

466

62

248

n/a

Major Source in Drinking Water

Runoff/leaching from natural deposits; seawater influence

Leaching from natural deposits

Substances that form ions when in water; seawater influence

Naturally-occurring organic materials Runoff/leaching from natural deposits

Soil runoff

GENERAL WATER QUALITY PARAMETERS

Alkalinity (mg/L)

Ammonia (mg/L)

Bromide (mg/L)

Calcium (mg/L)

Hardness (mg/L) Magnesium (mg/L) pH

Potassium (mg/L) Sodium (mg/L)

State or

Federal Goal

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

Highest Amt.

Allowed

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

n/a

Range

Detected

63–115

0.6

ND–0.3

16–31

83–149

11–18

7.6–8.5

1.9–3.2

47–78

Average

84

n/a

0.1

22

112

14

8.0

2.5

63

Range

Detected

51–90

0.5

ND–0.2

12–25

64–120

8.2–14

7.8–8.7

1.8–3.3

39–74

Average

65

n/a

0.1

17

89

11

8.2

2.5

55

PUBLIC MEETINGS

Fourth Wednesday 6:30 p.m.

87 Carol Lane Oakley, CA 94561

925-625-3798 diablowater.org

UCMR4 ASSESSMENT MONITORING 2018–2020

If you have any

Manganese (µg/L)

HAA5 (µg/L)

HAA Br (µg/L)

HAA9 (µg/L)

Total Organic Carbon (TOC) (µg/L)

Bromide (µg/L)

State or

Federal Goal

n/a

n/a

n/a

n/a

n/a

n/a

Notification

Level

500

n/a

n/a

n/a

n/a

n/a

Range

Detected

2.7–62

2.5–9.5

3.1–14

3.6–18

2,000–

4,400

88–261

Average

19

5.1

6.1

8.6

3,275

185

Range

Detected

0.9–45

n/a

n/a

n/a

2,000–

4,300

88–275

Average

12

n/a

n/a

n/a

3,000

191

questions about Diablo Water District tap water, please call 925-625-2112.

UNTREATED WATER TEST RESULTS

Radiochemistry

State or

Highest Amt.

Range

Federal Goal

Allowed

Detected

 

Uranium (pCi/L)

0.43

20

1.8–2.2

Average

2.0

Range

Detected

n/a

Average

n/a

2020 ANNUAL WATER QUALITY REPORT 11

This report contains important information about your drinking water. Have someone translate it for you, or speak with someone who understands it.

Su informe anual de la calidad del agua en español está disponible en línea

en ccwater.com/awqr_es. Este informe contiene información importante sobre su agua potable.

Mahalaga ang impormasyong ito. Mangyaring ipasalin ito.

WANT MORE INFORMATION?

Contra Costa Water District’s website contains valuable information about water issues. Visit ccwater.com to begin your research.

Contaminants


City of Antioch

EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the California State Water Resources Control Board, as well as information from the U.S. EPA Enforcement and Compliance History database (ECHO). For the latest quarter assessed by the U.S. EPA (January 2019 - March 2019), tap water provided by this water utility was in compliance with federal health-based drinking water standards.

Utility details

  • Serves: 103833
  • Data available: 2012-2017
  • Data Source: Surface water
  • Total: 11

Contaminants That Exceed Guidelines

  • Chromium (hexavalent)
  • Total trihalomethanes (TTHMs)

Other Detected Contaminants

  • Chlorate
  • Dichloromethane (methylene chloride)
  • Fluoride
  • Haloacetic acids (HAA5)
  • Molybdenum
  • Nitrate
  • Nitrate and nitrite
  • Strontium
  • Vanadium

Reminder

Always take extra precautions, the water may be safe to drink when it leaves the sewage treatment plant but it may pick up pollutants during its way to your tap. We advise that you ask locals or hotel staff about the water quality. Also, note that different cities have different water mineral contents.

Sources and Resources

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