Consumer Confidence Report
2017 for the year 2016


Message from the Assistant General Manager

Last year, as in years past, your tap water met all United States Environmental Protection Agency (USEPA) and State drinking water health standards. The City of Corona Department of Water and Power (DWP) vigilantly safeguards its water supplies, and once again, we are proud to report that our system did not exceed any of the Maximum Contaminant Levels (MCLs) or any other water quality standard. This report is a snap shot of last year’s water quality. Included are details about where your water comes from, what it contains, and how it compares to State standards. We are committed to providing you with information because informed customers are our best customers.

This year, California experienced a very wet winter which lead to Governor Brown rolling back the drought state of emergency in California. I want to take this opportunity to express gratitude to every resident and business in Corona for your tremendous conservation efforts during the drought. We saved nearly 20% during the drought period! This was a huge accomplishment for the City.

That being said, we still live in a dry and arid climate and we must continue to be vigilant in reducing water waste. Our new campaign slogan is “Water Efficiency Always.” We are asking Corona to make water efficiency a priority to help ensure our water supply remains healthy for years to come. Please help us reduce water waste by fixing leaks and broken sprinklers quickly, and watering your landscaping according to the current watering guidelines. The watering guidelines can be found on our website at www.CoronaDWP.org. Thank you again for your commitment to Corona and for helping us achieve our water conservation goals. We couldn’t do it without you!

I invite you to please contact me with any questions on this report or if you need additional information.

Tom Moody
Assistant General Manager
951-736-2477
www.CoronaDWP.org


Corona’s Water Sources

In 2016, Corona residents and businesses used approximately 9.7 billion gallons of drinking water. Corona’s water supply comes from three main sources: local groundwater, the Colorado River and the State Water Project in Northern California. Groundwater wells owned and operated by the City of Corona provided 47.5% of our water supply, 44.8% came through Lake Mathews from the Colorado River, 6.7% was from the State Water Project’s California Aqueduct and the final 1% was purchased from Western Municipal Water District’s Arlington Desalter treatment facility.


Water Treatment Processes

The surface water from the Colorado River requires treatment to become drinking water. The treatment process is accomplished in the City of Corona’s two surface water treatment facilities: Sierra Del Oro and Lester. These facilities incorporate the use of coagulants, which bind small particles together to form larger particles that can be easily removed through multimedia filtration. After filtration, the water is treated with sodium hypochlorite (NaOCl) to kill or inactivate harmful organisms. This part of the process is called disinfection. Through independent laboratory testing, 100% of the samples taken in 2016 were free of harmful organisms.

About half of the groundwater pumped in Corona is sent through a state- ofthe- art reverse osmosis membrane treatment facility, the Temescal Desalter. This facility provides removal of nitrates, per-fluorinated compounds, 1,2,3-Trichloropropane (123-TCP), perchlorates, and suspended and dissolved solids. Addition of NaOCl is also performed at this facility to maintain chlorine residual in the water distribution system and act as a disinfectant. DWP adds an ammonium hydroxide (NH4OH) solution to the disinfected water which in conjunction with NaOCl forms a compound called chloramines. This chemical acts as a disinfectant in the distribution system and remains active for a longer period of time than NaOCI alone. It also helps reducing the formation of disinfection by products that could be harmful to health. Disinfection byproducts are formed when some disinfectants like chlorine react with naturally occurring organic matter in the water.


Blending

DWP has five blending facilities that blend water with low nitrate, fluoride, perchlorate and Total Dissolved Solids (TDS) with the remaining groundwater sources to deliver safe, reliable drinking water to your tap. You will notice in the tables of detected contaminants that the groundwater exceeds the primary standard for fluoride, nitrate and perchlorate. DWP is required by law to report the range of all samples monitored, as well as the average concentration delivered to your tap. The averages of what you receive at your tap are much lower because DWP treats and blends water from several sources to improve water quality. The blending stations are continuously monitored and routinely sampled to ensure that the water delivered to your tap meets all health standards with a safety margin of no less than 10%. Please refer to the “Treated Average System Water” column in the tables at the end of the report for a more accurate representation of system water quality.

For more information about fluoridation, oral health, and current issues visit: http://www.waterboards.ca.gov/drinking_water/certlic/ drinkingwater/Fluoridation.shtml.


Governor Brown’s Executive Order B-40-17

Following water conservation and plentiful winter rain and snow, Governor Edmund G. Brown Jr. ended the drought state of emergency in most of California on April 7, 2017, while maintaining water reporting requirements and prohibitions on wasteful practices, such as watering during or right after rainfall. The State released a long-term plan to better prepare the state for future droughts and make conservation a California way of life. Building on the successes and lessons learned from California’s five-year drought, the plan establishes a framework for long-term efficient water use that reflects the State’s diverse climate, landscape, and demographic conditions.


Corona’s Response to the Governor’s Mandate

DWP thanks everyone for their overwhelming participation in conservation over the year. Thanks to everyone’s efforts Corona conserved nearly 3.7 billion gallons from June 2015 through March 2017, a reduction of 18% compared to water used during 2013. We ask that everyone be water efficient in their water usage, by requiring all residents and businesses in DWP’s service area to follow the water use guidelines below:


Rebates for Water Saving Appliances and Devices

Improve the water use efficiency at your home or business by upgrading your appliances and fixtures to water efficient models. DWP offers rebates for a variety of water saving appliances, devices, and fixtures. For inside the home, DWP offers several rebates to help you conserve water. By upgrading your clothes washer to a high efficiency model you can save an average of 14 gallons of water per day, as well as save on energy. Using less water and energy with a high efficiency clothes washer (HECW) reduces your monthly bills and can save you over $400 over the lifetime of the HECW. On average, nearly 30% of water usage in the home goes toward flushing the toilet. Rebates are available for residents who replace toilets that use 1.6 gallons per flush (gpf ) or more with new 1.06 gpf premium high efficiency toilets. The premium high efficiency toilets that qualify for the rebate have been performance tested and certified through MAP testing to ensure performance quality.

DWP offers a $50 rebate for newly-installed recirculating hot water systems. A recirculating hot water system uses a by-pass valve that connects the cold and hot water supply lines at the fixture that is farthest away from the water heater. The by-pass valve uses the cold water line as the return loop back to the water heater, continuously recirculating hot water. We also offer free water saving showerheads and faucet aerators for the bathroom and kitchen sinks. You can pick up your free devices at the Utility Billing counter at City Hall or contact the Water Resources Team at 951-736-2234 or e-mail StopTheDrop@CoronaCA.gov.

To help you improve water efficiency outdoors, DWP offers rebates on a variety of devices. Ensure your sprinklers are delivering a uniform and effective spray stream by upgrading your sprinkler nozzles to precision nozzles. For larger areas, consider upgrading your rotors to high efficiency multi-projectory nozzles and get a rebate! Once you have your irrigation system operating efficiently, it’s time to upgrade your irrigation timer to a weather-based model that automatically adjusts the watering schedule based on the weather conditions. Never get caught watering during the rain again with a weather-based irrigation controller (WBIC).

To learn more about the rebates available, visit www.discovercoronadwp. com/conservation/res-rebates.shtml.


Water Efficiency Rebates for Businesses

DWP offers numerous rebates just for businesses to help them improve water efficiency and keep the water bill down. Available rebated technologies and fixtures include:

For more information on these and other water efficiency rebates available to Corona businesses, contact the Water Resources Team at (951) 736-2234 or e-mail StopTheDrop@CoronaCA.gov.


Water: An Undervalued Resource

Earth is called the blue planet because most of its surface is covered with water. Yet only 3% of the earth’s water is fresh water that can be used for drinking, with 2/3 stored in ice caps and glaciers. That’s a small amount of water for everyone on the planet to share. Yet many of us don’t think twice about the water that we use every day. All too often, water that has been pumped in from afar and treated for human consumption can be seen running down the storm drains – wasted.

At a cost of less than a penny a gallon, the true value of water is not represented in the price. Water is a precious resource; we all need water to live. The drought California experienced over the past five years has proven that the water supply can be highly variable, with many factors that affect it, including drought, legislative restrictions, water quality issues, and environmental needs.

We must always use our resources efficiently, and focus on sustainable water supplies. Make every drop count – use water efficiently always.


Tour Our Facilities: In Person or on the Web!

A lot goes on behind the scenes to provide our customers with clean and affordable drinking water. Do you want to learn more about how your water is treated and delivered? Are you interested in seeing how we produce reclaimed water? If you have any questions about our water supply or water reclamation facilities, or you’re just curious, we encourage you to attend one of our quarterly facility tours. Visit our website at www.discovercoronadwp.com/education/facilitytour.shtml to be put on an interest list for future tours, or contact our Water Resources Team at 951-736-2234 or by e-mail at StopTheDrop@CoronaCA.gov to sign up for an upcoming tour. You must be at least 18 years old and a customer of the Department of Water and Power to attend.

Don’t have the spare time to come on a tour? The Department of Water and Power has created 11 videos of our facilities and services for you to watch from the convenience of your home computer or tablet. Simply go to our website at www.discovercoronadwp.com/about/ video.shtml.


Reclaimed Water

To improve water supply reliability for the City, DWP developed and built our reclaimed water system in 2006. Utilizing reclaimed water to help meet water demands for the City reduces the impact of imported water supply shortages and costs.

The reclaimed water system uses highly treated wastewater from our state-of-the-art water reclamation facilities and distributes it throughout the City. The reclaimed water system is completely separate from the drinking water system; pipes, sprinkler caps and signage are colored purple to easily identify them as part of the reclaimed water system. Reclaimed water is used primarily on landscaping at parks, schools, parkway areas, and some commercial buildings. By re-using water we save potable water for our homes and businesses. A rebate incentive is offered for businesses that convert their landscape irrigation and/or process operation water use to reclaimed water. Save water and get funding assistance to cover the cost of the conversion. Contact the Water Resources Team at (951) 736-2234 or by e-mail at StopTheDrop@CoronaCA.gov to see if your business qualifies.

The City of Corona’s infrastructure for the reclaimed water system consists of approximately 54.6 miles of pipeline, three storage tanks, and four pump stations. Of the reclaimed water produced, 1.77 billion gallons went into the reclaimed water distribution system for customer use. We currently have 345 connections, and are continually adding new sites.


From Your Drain to the Environment – Keep It Clean

While water reclamation treatment removes most pollutants, even trace amounts of some substances may be harmful to the environment. The best solution is to prevent pollution from going down the drain in the first place.

Dispose of unwanted medicine properly… No Drugs down the Drain!

For years, unwanted medicine was flushed down the drain to protect children and pets from accessing it, and to ensure against illegal recovery of controlled substances. Today, there are better options. The City of Corona DWP and the Police Department are working together to protect our environment from the harmful effects of improperly discarded, unused medications. Unused medication can be dropped off at the Corona Police Department by appointment only. For more information, please call 951‑736‑2330.

Keep drains free of FOG – Fats, Oils and Grease

When washed down the drain, cooking fats, oils and grease, or “FOG,” can block sewer lines, causing raw sewage to back up into your home or into neighborhood streets and storm drains. Overflows can be costly, and pose health and environmental hazards. Keep your sewer lines FOG-free by scraping cooking fats into the garbage or into your food scrap recycling bin, where available – not down the drain.


General Water Quality Information

The sources of drinking water (both tap 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 include:

In order to ensure that tap water is safe to drink, the USEPA and the State Water Resources Control Board (SWRCB) prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. SWRCB 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. 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 (1-800-426-4791).

This Consumer Confidence Report (CCR) reflects changes in drinking water regulatory requirements during 2016. All water systems are required to comply with the state Total Coliform Rule. Beginning April 1, 2016, all water systems are also required to comply with the federal Revised Total Coliform Rule. The new federal rule maintains the purpose to protect public health by ensuring the integrity of the drinking water distribution system and monitoring for the presence of microbials (i.e., total coliform and E. coli bacteria). The USEPA anticipates greater public health protection as the new rule requires water systems that are vulnerable to microbial contamination to identify and fix problems. Water systems that exceed a specified frequency of total coliform occurrences are required to conduct an assessment to determine if any sanitary defects exist. If found, these must be corrected by the water system.

Nitrate

Nitrate in drinking water at levels above 45 ppm is a health risk especially for infants of less than six months of age. Such nitrate levels in drinking water can interfere with the capacity of the infant’s blood to carry oxygen, resulting in a serious illness; symptoms include shortness of breath and blueness of the skin. Nitrate levels above 45 parts per million (ppm) may also affect the ability of the blood to carry oxygen in other individuals, such as pregnant women and those with certain specific enzyme deficiencies. If you are caring for an infant, or you are pregnant, you should ask advice from your health care provider.

Source Water Assessment

In accordance with the Federal Safe Drinking Water Act (SDWA), the SWRCB Division of Drinking Water and Environmental Management developed a program, called the Drinking Water Source Assessment and Protection (DWSAP) Program, to assess the vulnerability of drinking water sources to contamination. Assessments of the drinking water sources for the City of Corona were completed most recently in February 2012. The assessment concluded that the City of Corona’s sources are considered most vulnerable to the following activities not associated with any detected contaminants in the water supply: automobile – gas stations, chemical/petroleum pipelines, chemical/ petroleum processing/storage, dry cleaners, historic gas stations, machine shops, metal plating/finishing/fabricating, mining – sand/gravel, NPDES/WDR permitted discharges, plastics/synthetics producers, septic systems – low density [<1/acre], sewer collection systems, underground storage tanks – confirmed leaking tanks, utility stations – maintenance areas, and wastewater treatment plants. A copy of the complete assessments are available through the City of Corona’s City Clerk’s office at 400 S. Vicentia, Corona, CA 92882, or by using the online Public Records Request form at http://www.discovercorona. com/Online-Services/Public-Records-Request.aspx.

Lead and Copper Rule Monitoring

The Lead and Copper Rule (LCR) was developed to protect public health by minimizing lead and copper levels in drinking water. The LCR established an action level of 15 parts per billion (ppb) for lead and 1.3 parts per million (ppm) for copper, based on the 90th percentile level of tap water samples collected. Lead and copper are sampled on a mandated three-year testing cycle with sampling conducted at the customer’s tap.

Parameter Units State MCL
PHG State DLR Date Sampled 90th Percentile No. Sites Sampled No. Sites Exceeding AL
Lead
ppb AL=15 0.2 5 2014 2 50 0
Copper ppm AL=1.3 0.3 0.05 2014 0.11 50 0

AL         Allowable Levels
DLR      Detection Limits for purposes of Reporting
MCL      Maximum Contaminant Level
PHG      Public Health Goal
ppb       Parts per billion or micrograms per liter (μg/L)
ppm      Parts per million or milligrams per liter (mg/L)

Lead

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 home plumbing. The City of Corona 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 2 minutes before using water for drinking or cooking. 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 or at http://www.epa.gov/lead.

Primary Standards —
Mandatory Health-Related Standards 

Clarity

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

Water Source

Major Sources in
Drinking Water

Combined Filter
Effluent Turbidity

%

95(a)

NA

% < 0.3

100

Metropolitan Water District, Henry J. Mills Water Treatment Plant

Soil runoff

NTU

TT 0.3

Highest

0.1

Combined Filter
Effluent Turbidity

%

95(a)

NA

% < 0.3

100

City of Corona, Lester & Sierra Del Oro Water Treatment Facilities

Soil runoff

NTU

TT 0.3

Highest

0.08

Microbiological Contaminants

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

 Regulated in Distribution System

Major Sources in
Drinking Water

Total Coliform Bacteria
(State Total Coliform Rule)

%

5.0 (b)

0

Highest % of positive samples collected in any one month = 1%

Naturally present in the environment

Fecal Coliform and
E. Coli
(State Total Coliform Rule)

(c)

(c)

0

Total number of positive samples collected in 2016 = 0

Human and animal fecal waste

Total Coliform Bacteria
(Federal Total Coliform Rule)

%

TT(s)

Highest % of positive samples collected in any one month = 1%

Naturally present in the environment

Fecal Coliform and
E. Coli
(Federal Total Coliform Rule)

(t)

(t)

(o)

Total number of positive samples collected in 2016 = 0

Human and animal fecal waste

Heterotrophic Plate Count (HPC)

CFU/mL

TT

N/A

N/A

Range

Distribution System Wide: 
ND-1,500

Naturally present in the environment

Average

Distribution System Wide: 13

Radioactive Contaminants(u)

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

State Project Water

Colorado River Water

Arlington Desalter

Ground Water

Treated Average System Water

Major Sources in
Drinking Water

Gross Alpha
Particle Activity

pCi/L

15

(0)

3

Range

ND-4

ND-4

5.96

ND-8.8

-

Erosion of natural deposits

Average

ND

3

5.96

1.84

-

Uranium

pCi/L

20

0.43

1

Range

ND-4

2-3

2.69

ND-18

-

Erosion of natural deposits

Average

2

3

2.69

4.79

-

Inorganic Contaminants

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

State Project Water

Colorado River Water

Arlington Desalter

Ground Water

Treated Average System Water

Major Sources in
Drinking Water

Arsenic

ppb

10

0.004

2

Range

2.5

2.4

ND

ND-3.2

ND-2.7

Erosion of natural deposits; runoff from orchards; glass and electronics production wastes

Average

2.5

2.4

ND

ND

ND

Barium

ppm

1

2

0.1

Range

ND

0.14

ND

ND-0.18

ND-0.13

Discharges of oil drilling wastes and from metal refineries; erosion of natural deposits

Average

ND

0.14

ND

ND

ND

Fluoride
(e, h, k)

ppm

2.0

1

0.1

Range

0.5-0.8

0.3

ND-0.1

ND-2.7

ND-0.76

Erosion of natural deposits; water additive that promotes strong teeth; discharge from fertilizer and aluminum factories

Average

0.7

0.3

ND

0.45

0.24

Hexavalent Chromium

ppb

10

0.02

1

Range

ND

ND

-

ND-2.2

ND

Discharge from electroplating factories, leather tanneries, wood preservation, chemical synthesis, refractory production, and textile manufacturing facilities; erosion of natural deposits

Average

ND

ND

-

ND

ND

Nitrate (as N) (e, k)

ppm

10

10

0.4

Range

0.4-1.1

ND

2.9-4.6

ND-21

ND-8.1

Runoff and leaching from fertilizer use; leaching from septic tanks and sewage; erosion of natural deposits

Average

0.8

ND

4.1

10

3.6

Perchlorate (e, k)

ppb

6

1

4

Range

ND

ND

ND

ND-

ND

Perchlorate is an inorganic chemical used in solid rocket propellant, fireworks, explosives, flares, matches, and a variety of industries.  It usually gets into drinking water as a result of environmental contamination from historic aerospace or other industrial operations that used or use, store, or dispose of perchlorate and its salts.

Average

ND

ND

ND

ND

ND

Selenium

ppb

50

30

5

Range

ND

ND

ND

ND-18

ND

Discharge from petroleum, glass, and metal refineries;  erosion of natural deposits;  discharge from mines and chemical manufacturers; runoff from livestock lots (feed additive)

Average

ND

ND

ND

ND

ND

Synthetic Organic Contaminants (including Pesticides/PCBs)

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

State Project Water

Colorado River Water

Arlington Desalter

Ground Water

Treated Average System Water

Major Sources in
Drinking Water

Dibromo-chloro-propane (DBCP)

ppt

200

1.7

10

Range

ND

ND

ND

ND-19

ND

Banned nematocide that may still be present in soils due to runoff/leaching from former use on soybeans, cotton, vineyards, tomatoes, and tree fruit

Average

ND

ND

ND

ND

ND

Volatile Organic Contaminants

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

State Project Water

Colorado River Water

Arlington Desalter

Ground Water

Treated Average System Water

Major Sources in
Drinking Water

Tetrachloro-ethylene (PCE)

ppb

5

0.06

0.5

Range

ND

ND

ND

ND-0.53

ND

Discharge from factories, dry cleaners, and auto shops (metal degreaser)

Average

ND

ND

ND

ND

ND

Trichloro-ethylene (TCE)

ppb

5

1.7

0.5

Range

ND

ND

ND

ND-1.6

ND

Discharge from metal degreasing sites and other factories

Average

ND

ND

ND

0.6

ND

Secondary  Standards—Aesthetic Standards

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

State Project Water

Colorado River Water

Arlington Desalter

Ground Water

Treated Average System Water

Major Sources in
Drinking Water

Aluminum
(i)

ppb

200

600

50

Range

93-150

ND

ND

ND

ND-870

Erosion of natural deposits; residual from some surface water treatment processes

Max RAA

122

79

ND

ND

262

Chloride

ppm

500

NA

NA

Range

78-89

97-98

36-42

ND-240

26-100

Runoff/leaching from natural deposits; seawater influence

Average

84

98

39

132

66

Corrosivity (as Aggressive-ness Index)

AI

NA

NA

NA

Range

-

-

-

12-13

10-12

Elemental balance in water; affected by temperature, other factors

Average

12

-

-

12

11.5

Foaming Agents (MBAS)

ppb

500

NA

NA

Range

ND

ND

ND-80

ND-210

ND

Municipal and industrial waste discharges

Average

ND

ND

ND

ND

ND

Manganese
(f, k)

ppb

50

NL= 500

20

Range

ND

ND

ND

ND-620

ND

Leaching from natural deposits

Average

ND

ND

ND

34

ND

Odor Threshold
(k)

ppb

3

NA

NA

Range

2

2

ND

ND-100

1-2

Naturally-occurring organic materials

Average

2

2

ND

6.8

1.7

Specific Conductance
(k)

µS/
cm

1,600

NA

NA

Range

475-570

1000-1050

298-584

3-1950

179-1090

Substances that form ions when in water; seawater influence

Average

522

1025

449

1295

636

Sulfate

ppm

500

NA

0.5

Range

29-72

250-251

42-47

ND-370

3-250

Runoff/leaching from natural deposits; industrial wastes

Average

50

251

45

192

121

Total Dissolved Solids
(e, j, k)

ppm

1,000

NA

NA

Range

261-326

632-643

210-310

ND-1,200

110-690

Runoff/leaching from natural deposits

Average

294

638

248

820

396

Turbidity

ppb

5

NA

NA

Range

ND

0.8-1.7

ND-0.14

ND-1.2

ND-3.3

Soil runoff

Average

ND

1.2

ND

0.1

1.1

Unregulated Contaminants with No MCLS (g)

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

State Project Water

Colorado River Water

Arlington Desalter

Ground Water

Treated Average System Water

Health Effects

Boron (p)

ppm

NA

NL=1

0.1

Range

0.24

0.15

-

0.35-5.1

0.13-0.43

The babies of some pregnant women who drink water containing boron in excess of the notification level may have an increased risk of developmental effects, based on studies in laboratory animals.

Average

0.24

0.15

-

1.98

0.24

Vanadium

ppb

NA

NL=50

3

Range

8.9

ND

4.8-6

ND-9.2

ND-3.1

The babies of some pregnant women who drink water containing vanadium in excess of the notification level may have an increased risk of developmental effects, based on studies in laboratory animals.

Average

8.9

ND

5.4

5.1

ND

Federal Unregulated Contaminants Monitoring Rule (UCMR3) (d)

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

Distribution System

1,4-Dioxane

ppb

NA

NA

0.07

Range

ND-0.14

Average

ND

Chlorate

ppb

NA

NA

20

Range

75-360

Average

152

Chromium

ppb

NA

NA

0.2

Range

ND-0.52

Average

ND

Hexavalent Chromium (Dissolved)

ppb

NA

NA

0.03

Range

ND-0.43

Average

0.134

Molybdenum

ppb

NA

NA

1

Range

ND-17

Average

3.7

Strontium

ppb

NA

NA

0.3

Range

25-1100

Average

589

Vanadium

ppb

NA

NA

0.2

Range

ND-6.4

Average

2.4

Perfluoro octanesulfonic acid - PFOS

ppb

NA

NA

0.04

Range

ND-0.046

Average

ND

Perfluorooctanoic acid - PFOA

ppb

NA

NA

0.02

Range

ND-0.042

Average

ND

Perfluoroheptanoic acid - PFHpA

ppb

NA

NA

0.01

Range

ND-0.013

Average

ND

 

Other Parameters

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average

State Project Water

Colorado River Water

Arlington Desalter

Ground Water

Treated Average System Water

Alkalinity

ppm

NA

NA

NA

Range

64-78

120-131

59-95

ND-330

23-120

Average

71

126

87

205

70

Bicarbonate

ppm

NA

NA

NA

Range

-

-

72-120

ND-400

28-140

Average

-

-

106

251

81

Calcium

ppm

NA

NA

NA

Range

17-27

71-76

31-32

ND-180

3.6-83

Average

22

74

32

111

39

Hardness (q)

ppm

NA

NA

NA

Range

87-112

281-300

120-130

ND-690

13-320

Average

100

291

125

400

155

Magnesium

ppm

NA

NA

NA

Range

10

26

11-13

ND-71

0.83-28

Average

10

26

12

30

14

pH

ppm

NA

NA

NA

Range

8.3-8.6

8-8.2

7.8-8.5

6.3-11

6.9-9.4

Average

8.4

8.1

8.2

7.2

8

Potassium

ppm

NA

NA

NA

Range

2.7-2.8

4.9

1-1.2

ND-13

ND-5

Average

2.8

4.9

1.1

3.9

2.9

Sodium (r)

ppm

NA

NA

NA

Range

62-75

99-102

37-40

ND-180

30-100

Average

68

100

39

102

68

Disinfection Byproducts, Disinfectant Residuals, and Disinfection Byproduct Precursors Federal Rule(m)

Parameter

Units

State       
MCL
[MRDL]

PHG
(MCLG)
[MRDLG]

State
DLR

Range
Average/

LRAA/RAA

Distribution System Wide

Major Sources in Drinking Water

Health Effects Language

Total Trihalomethanes              (TTHMs) (n)

ppb

80

NA

1

Range

ND-44

Byproduct of drinking water disinfection

Some people who drink water containing trihalomethanes in excess of the MCL over many years may experience liver, kidney, or central nervous system problems, and may have an increased risk of getting cancer.

LRAA

32.8

Haloacetic Acids (o)

ppb

60

NA

1

Range

ND-13

Byproduct of drinking water disinfection

Some people who drink water containing haloacetic acids in excess of the MCL over many years may have an increased risk of getting cancer.

LRAA

9.9

Bromate (Mills - WR-24 Conn.) (l)

ppb

10

0.1

1

Range

ND-7

Byproduct of drinking water disinfection

Some people who drink water containing bromate in excess of the MCL over many years may have an increased risk of getting cancer.

Max RAA

4.5

Chloramines

ppb

[4.0 as Cl2]

[4.0 as Cl2]

NA

Range

0.3-2.7

Drinking water disinfectant added for treatment

Some people who use water containing chloramines well in excess of the MRDL could experience irritating effects to their eyes and nose.  Some people who drink water containing chloramines well in excess of the MRDL could experience stomach discomfort or anemia.

Max RAA

1.8

Control of DBP precursors  (TOC)

ppb

TT

NA

0.3

Range

2.3-2.7

Various natural and manmade sources

Total organic carbon (TOC) has no health effects.  However, total organic carbon provides a medium for the formation of disinfection byproducts.   These byproducts include trihalomethanes (THMs) and haloacetic acids (HAAs).  Drinking water containing these byproducts in excess of the MCL may lead to adverse health effects, liver or kidney problems, or nervous system effects, and may lead to an increased risk of cancer.

Average

2.4

 


Key to Abbreviations


Extended Abbreviations

Water-saving Tip: One unnecessary flush per day wastes up to 1,000 gallons of water over the course of a year.


Footnotes

(a) The turbidity level of the filtered water shall be less than or equal to 0.3 NTU in 95% of the measurements taken each month and shall not exceed 1 NTU at any time. Turbidity, a measure of the cloudiness of the water, is an indicator of treatment performance. The averages and ranges of turbidity shown in the Secondary Standards were based on the treatment plant effluent.

(b) Total coliform MCLs: No more than 5.0% of the monthly samples may be total coliform-positive. Compliance is based on the combined distribution system sampling from all the treatment plants. In 2016, 1,561 samples were analyzed and one was positive for total coliform. The MCL was not violated.

(c) E. coli MCL: The occurrence of two consecutive total coliform-positive samples, one of which contains E. coli, constitutes an acute MCL violation. The MCL was not violated.

(d) Data was collected in 2014 and reported per UCMR 3 guidance. Minimum reporting levels are as stipulated in the Federal UCMR 3. List 1 – Assessment
Monitoring consists of 21 chemical contaminants for which standard analytical methods were available. List 2 – Screening Survey consists of 7 contaminants for which new analytical methods were used. All analyses conducted by contract laboratories. Values listed in state DLR column are federal minimum reporting levels.

(e) Fluoride, nitrate, perchlorate, and TDS are a part of Corona’s blending remediation plan to reduce the levels being delivered to the consumer’s tap. Refer to the “Treated Average System Water” column for a more accurate representation of system water quality.

(f) The high concentration of Manganese is from two groundwater wells; the City utilizes over 20 wells. Refer to the “Treated Average System Water” column for a more accurate representation of system water quality.

(g) Unregulated contaminant monitoring helps the USEPA and the State Board determine where certain contaminants occur and whether the contaminants need to be regulated.

(h) City of Corona was in compliance with all provisions of the State’s Fluoridation System Requirements. This is part of the City of Corona’s blending plan to reduce the levels of fluoride being delivered to the consumer’s tap. Refer to the “Treated Average System Water” column for a more accurate representation of system water quality.

( i ) Aluminum has a secondary standard limit. In 2016, the secondary standard limit was exceeded at our Treatment Facility effluent with a Maximum Running Annual Average (Max RAA) of 262 ppb, exceedance shown in bold. No consumer action is necessary since secondary standards for aluminum are established only for aesthetic effects (water color). We are continually calibrating our aluminum base coagulant to achieve the non-mandatory secondary standard limit of 200 ug/L. We expect to achieve this limit by the end of 2017. Our current Max RAA for 2017 is 163 ug/L.

( j ) Total Dissolved Solids (TDS) is a measure of the total amount of all the materials that are dissolved in water. These minerals, both natural and anthropogenic (made by humans), are mainly inorganic solids, with a minor amount of organic material.

( k ) This constituent was detected at levels exceeding the MCL, results shown in bold. Please note that this water is treated or blended with water from other sources to provide customers with the highest quality drinking water.

( l ) Bromate reporting level is 3 ppb and reported from Mills Filtration Plant Metropolitan Water District (MWD). Mills MWD water is blended with other Corona water sources. Please note that this water is blended with water from other sources to provide customers with the highest quality drinking water.

(m) The City of Corona was in compliance with all provisions of the Stage 2 Disinfectants and Disinfection Byproducts Rules (D/DBP). Compliance was based on the locational running annual average (LRAA). The average reported reflects the highest TTHM and HAA5 LRAAs for the year.

(n) Reporting level is 0.5 ppb for each of the trihalomethanes (bromodichloro-methane, bromoform, chloroform, and dibromochloromethane).

(o) DLR is 1.0 ppb for each of the following: dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid; and 2.0 ppb for monochloroacetic acid.

(p) The sources that were detected for Boron are all directed to the Temescal Desalter for reverse osmosis treatment. The treated water is monitored at the effluent of the facility which is represented in the “Treated Average System Water” column.

(q) Hardness is the sum of polyvalent cations present in the water, generally magnesium and calcium. The cations are usually naturally occurring.

(r) Sodium refers to the salt present in the water and is generally naturally occurring.

(s) 5.0% total coliform-positive samples in a month trigger Level 1 assessments. Failure to conduct assessments and correct findings within 30 days is a total coliform violation. No triggers, Level 1 assessments, or violations occurred.

(t) E. coli MCL and Level 2 TT triggers for assessments: Routine and repeat samples are total coliform-positive and either sample is E. coli-positive or system fails to collect all repeat samples following an E. coli-positive sample, or fails to test for E. coli when the repeat sample is total coliform-positive. No samples were E. coli-positive. No MCLs violations or no assessments occurred.

(u) Results are from 2008-2016.


Frequently Asked Questions

If you are interested in participating in decisions that affect the quality and supply of the water in the City of Corona, or for general information about this report and questions related to water quality, please call 951-736-2234.

Regular City Council meetings are held on the first and third Wednesday of every month.

Did you know?
• There are 748 gallons of water in one billing unit.
• One acre-foot of water equals 325,829 gallons or 435.6 billing units.
• One acre-foot of water can supply two typical families with water for a whole year.
• A leaky toilet can waste between 30 to 500 gallons of water per day.