The City of St. Johns Annual Water Quality Report for the reporting year of 2016

Is my water safe?


We are pleased to present this year's Annual Water Quality Report (Consumer Confidence Report) as required by the Safe Drinking Water Act (SDWA). This report is designed to provide details about where your water comes from, what it contains, and how it compares to standards set by regulatory agencies. This report is a snapshot of last year's water quality. We are committed to providing you with information because informed customers are our best allies.

 

Do I need to take special precautions?


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. EPA/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 Water Drinking Hotline (800-426-4791)



 

 

Why are there contaminants in my drinking water?


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 Environmental Protection Agency's (EPA) Safe Drinking Water Hotline (800-426-4791). 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:
microbial contaminants, such as viruses and bacteria, that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife; inorganic contaminants, such as salts and metals, which can be naturally occurring or result from urban stormwater runoff, industrial, or domestic wastewater discharges, oil and gas production, mining, or farming; pesticides and herbicides, which may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses; organic Chemical Contaminants, including synthetic and volatile organic chemicals, which are by-products of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, and septic systems; and radioactive contaminants, which 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, EPA prescribes regulations that limit the amount of certain contaminants in water provided by public water systems. Food and Drug Administration (FDA) regulations establish limits for contaminants in bottled water which must provide the same protection for public health.

 

 

Water Conservation Tips

 

Did you know that the average U.S. household uses approximately 400 gallons of water per day or 100 gallons per person per day? Luckily, there are many low-cost and no-cost ways to conserve water. Small changes can make a big difference - try one today and soon it will become second nature.

 

Cross Connection Control Survey

 

The purpose of this survey is to determine whether a cross-connection may exist at your home or business. A cross connection is an unprotected or improper connection to a public water distribution system that may cause contamination or pollution to enter the system. We are responsible for enforcing cross-connection control regulations and insuring that no contaminants can, under any flow conditions, enter the distribution system. If you have any of the devices listed below please contact us so that we can discuss the issue, and if needed, survey your connection and assist you in isolating it if that is necessary.

 

Source Water Protection Tips

 

Protection of drinking water is everyone's responsibility. You can help protect your community's drinking water source in several ways:

 

Additional Information for 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. City of St. Johns 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/safewater/lead.

 


Water Quality Data Table

In order to ensure that tap water is safe to drink, EPA prescribes regulations which limit the amount of contaminants in water provided by public water systems. The table below lists all of the drinking water contaminants that we detected during the calendar year of this report. Although many more contaminants were tested, only those substances listed below were found in your water. All sources of drinking water contain some naturally occurring contaminants. At low levels, these substances are generally not harmful in our drinking water. Removing all contaminants would be extremely expensive, and in most cases, would not provide increased protection of public health. A few naturally occurring minerals may actually improve the taste of drinking water and have nutritional value at low levels. Unless otherwise noted, the data presented in this table is from testing done in the calendar year of the report. The EPA or the State requires us to monitor for certain contaminants less than once per year because the concentrations of these contaminants do not vary significantly from year to year, or the system is not considered vulnerable to this type of contamination. As such, some of our data, though representative, may be more than one year old. In this table you will find terms and abbreviations that might not be familiar to you. To help you better understand these terms, we have provided the definitions below the table.

 

Contaminants

MCLG
or
MRDLG

MCL,
TT, or
MRDL

Detect In
Your Water

Range

Sample
Date

Violation

Typical Source

Low

High

Disinfectants & Disinfection By-Products

(There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants)

TTHMs [Total Trihalomethanes] (ppb)

NA

80

1.8

1.8

1.8

2016

No

By-product of drinking water disinfection

Microbiological Contaminants

Total Coliform (RTCR) (% positive samples/month)

NA

TT

NA

NA

NA

2016

No

Naturally present in the environment

Radioactive Contaminants

Radium (combined 226/228) (pCi/L)

0

5

4.8

1.5

5.1

2016

No

Erosion of natural deposits

Synthetic organic contaminants including pesticides and herbicides

PCBs [Polychlorinated biphenyls] (ppt)

0

500

NA

NA

NA

2016

No

 

Contaminants

MCLG

AL

Your
Water

Sample
Date

# Samples
Exceeding AL

Exceeds AL

Typical Source

Inorganic Contaminants

Copper - action level at consumer taps (ppm)

1.3

1.3

.02

2016

No

Corrosion of household plumbing systems; Erosion of natural deposits

Inorganic Contaminants

Lead - action level at consumer taps (ppb)

0

15

1

2016

No

Corrosion of household plumbing systems; Erosion of natural deposits

 

Violations and Exceedances

 


Undetected Contaminants

The following contaminants were monitored for, but not detected, in your water.

 

Contaminants

MCLG
or
MRDLG

MCL,
TT, or
MRDL

Your
Water

Violation

Typical Source

1,1,1-Trichloroethane (ppb)

200

200

ND

No

Discharge from metal degreasing sites and other factories

1,1,2-Trichloroethane (ppb)

3

5

ND

No

Discharge from industrial chemical factories

1,1-Dichloroethylene (ppb)

7

7

ND

No

Discharge from industrial chemical factories

1,2,4-Trichlorobenzene (ppb)

70

70

ND

No

Discharge from textile-finishing factories

1,2-Dichloroethane (ppb)

0

5

ND

No

Discharge from industrial chemical factories

1,2-Dichloropropane (ppb)

0

5

ND

No

Discharge from industrial chemical factories

2,4,5-TP (Silvex) (ppb)

50

50

ND

No

Residue of banned herbicide

2,4-D (ppb)

70

70

ND

No

Runoff from herbicide used on row crops

Alachlor (ppb)

0

2

ND

No

Runoff from herbicide used on row crops

Atrazine (ppb)

3

3

ND

No

Runoff from herbicide used on row crops

Benzene (ppb)

0

5

ND

No

Discharge from factories; Leaching from gas storage tanks and landfills

Benzo(a)pyrene (ppt)

0

200

ND

No

Leaching from linings of water storage tanks and distribution lines

Carbofuran (ppb)

40

40

ND

No

Leaching of soil fumigant used on rice and alfalfa

Carbon Tetrachloride (ppb)

0

5

ND

No

Discharge from chemical plants and other industrial activities

Chlordane (ppb)

0

2

ND

No

Residue of banned termiticide

Chlorobenzene (monochlorobenzene) (ppb)

100

100

ND

No

Discharge from chemical and agricultural chemical factories

Dalapon (ppb)

200

200

ND

No

Runoff from herbicide used on rights of way

Di (2-ethylhexyl) adipate (ppb)

400

400

ND

No

Discharge from chemical factories

Di (2-ethylhexyl) phthalate (ppb)

0

6

ND

No

Discharge from rubber and chemical factories

Dibromochloropropane (DBCP) (ppt)

0

200

ND

No

Runoff/leaching from soil fumigant used on soybeans, cotton, pineapples, and orchards

Dichloromethane (ppb)

0

5

ND

No

Discharge from pharmaceutical and chemical factories

Dinoseb (ppb)

7

7

ND

No

Runoff from herbicide used on soybeans and vegetables

Dioxin (2,3,7,8-TCDD) (ppq)

0

30

ND

No

Emissions from waste incineration and other combustion; Discharge from chemical factories

Diquat (ppb)

20

20

ND

No

Runoff from herbicide use

Endothall (ppb)

100

100

ND

No

Runoff from herbicide use

Endrin (ppb)

2

2

ND

No

Residue of banned insecticide

Ethylbenzene (ppb)

700

700

ND

No

Discharge from petroleum refineries

Ethylene dibromide (ppt)

0

50

ND

No

Discharge from petroleum refineries

Glyphosate (ppb)

700

700

ND

No

Runoff from herbicide use

Haloacetic Acids (HAA5) (ppb)

NA

60

ND

No

By-product of drinking water chlorination

Heptachlor (ppt)

0

400

ND

No

Residue of banned pesticide

Heptachlor epoxide (ppt)

0

200

ND

No

Breakdown of heptachlor

Hexachlorobenzene (ppb)

0

1

ND

No

Discharge from metal refineries and agricultural chemical factories

Hexachlorocyclopentadiene (ppb)

50

50

ND

No

Discharge from chemical factories

Lindane (ppt)

200

200

ND

No

Runoff/leaching from insecticide used on cattle, lumber, gardens

Methoxychlor (ppb)

40

40

ND

No

Runoff/leaching from insecticide used on fruits, vegetables, alfalfa, livestock

Nitrate [measured as Nitrogen] (ppm)

10

10

ND

No

Runoff from fertilizer use; Leaching from septic tanks, sewage; Erosion of natural deposits

Oxamyl [Vydate] (ppb)

200

200

ND

No

Runoff/leaching from insecticide used on apples, potatoes and tomatoes

Pentachlorophenol (ppb)

0

1

ND

No

Discharge from wood preserving factories

Picloram (ppb)

500

500

ND

No

Herbicide runoff

Simazine (ppb)

4

4

ND

No

Herbicide runoff

Styrene (ppb)

100

100

ND

No

Discharge from rubber and plastic factories; Leaching from landfills

Tetrachloroethylene (ppb)

0

5

ND

No

Discharge from factories and dry cleaners

Toluene (ppm)

1

1

ND

No

Discharge from petroleum factories

Toxaphene (ppb)

0

3

ND

No

Runoff/leaching from insecticide used on cotton and cattle

Trichloroethylene (ppb)

0

5

ND

No

Discharge from metal degreasing sites and other factories

Vinyl Chloride (ppb)

0

2

ND

No

Leaching from PVC piping; Discharge from plastics factories

Xylenes (ppm)

10

10

ND

No

Discharge from petroleum factories; Discharge from chemical factories

cis-1,2-Dichloroethylene (ppb)

70

70

ND

No

Discharge from industrial chemical factories

p-Dichlorobenzene (ppb)

75

75

ND

No

Discharge from industrial chemical factories

trans-1,2-Dichloroethylene (ppb)

100

100

ND

No

Discharge from industrial chemical factories

 


Unit Descriptions

Term

Definition

ppm

ppm: parts per million, or milligrams per liter (mg/L)

ppb

ppb: parts per billion, or micrograms per liter (g/L)

ppt

ppt: parts per trillion, or nanograms per liter

ppq

ppq: parts per quadrillion, or picograms per liter

pCi/L

pCi/L: picocuries per liter (a measure of radioactivity)

% positive samples/month

% positive samples/month: Percent of samples taken monthly that were positive

NA

NA: not applicable

ND

ND: Not detected

NR

NR: Monitoring not required, but recommended.

 

Important Drinking Water Definitions

Term

Definition

MCLG

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

MCL

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

TT

TT: Treatment Technique: A required process intended to reduce the level of a contaminant in drinking water.

AL

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

Variances and Exemptions

Variances and Exemptions: State or EPA permission not to meet an MCL or a treatment technique under certain conditions.

MRDLG

MRDLG: Maximum residual disinfection level goal. 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.

MRDL

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

MNR

MNR: Monitored Not Regulated

MPL

MPL: State Assigned Maximum Permissible Level

 

For more information please contact:

Contact Name: Dana Waite
Address: PO Box 455
St. Johns, Az 85936
Phone: 928.337.2031