Orange Water and Sewer Authority
400 JONES FERRY ROAD
CARRBORO NC 27510
Telephone: (919) 968-4421 or E-mail: OWASA

 

Test Results Summary For 2003

Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

Microbiological

Total Coliform Bacteria (percent)

1

0 to 1

presence of coliform bacteria in greater than 5% of the monthly samples

0

Naturally present in the environment

E. coli Bacteria

(percent)

0

no range

a routine sample and a repeat sample are total coliform positive, and one is also fecal coliform or E. coli positive

0

Human and animal fecal waste

Turbidity

(NTU)

0.22

 

and 100% of samples below 0.3

0.02 to 0.22

1.0

 

and 95% of samples

below 0.3

0.3

A measure of the cloudiness of water. It may be caused by inorganic soil particles or fragments of organic matter that can interfere with treatment.

Radiological

Gross Beta

(pCi/L)

 

BDL

no range

50

0

Decay of natural and man-made deposits

Gross Alpha

(pCi/l)

 

BDL

no range

15

0

Erosion of natural deposits

Radium 228

(pCi/l)

 

BDL

no range

2

0

Erosion of natural deposits

Inorganics

Antimony

(ppb)

BDL

no range

6

6

Discharge from petroleum refineries; fire retardants; ceramics; electronics; solder

Arsenic

(ppb)

BDL

no range

10

N/A

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

 


Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

Asbestos

(MFL)

(last tested in 2002)

BDL

no range

7

7

Decay of asbestos-cement water mains; erosion of natural deposits

Last tested 9/93

Barium

(ppm)

BDL

no range

2

2

Discharge of drilling wastes; discharge from metal refineries; erosion of natural deposits

Beryllium

(ppb)

BDL

no range

4

4

Discharge from metal refineries and coal-burning factories; discharge from electrical, aerospace, and defense industries

Cadmium

(ppb)

BDL

no range

5

5

Corrosion of galvanized pipes; erosion of natural deposits; discharge from metal refineries; runoff from waste batteries and paints

Chromium

(ppb)

BDL

no range

100

100

Discharge from steel and pulp mills; erosion of natural deposits

Copper

(ppm)

(last tested in 2002)

0.160

(90 th percentile,

with 0 sample sites above the action level)

0.026 to 0.580

1.3 (action level)

1.3

Corrosion of household plumbing systems; erosion of natural deposits; leaching from wood preservatives

Cyanide

(ppb)

BDL

no range

200

200

Discharge from steel/metal factories; discharge from plastic and fertilizer factories

Fluoride

(ppm)

0.91

0.86 to 0.91

4

4

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

Lead

(ppb)

(last tested in 2002)

4

(90 th percentile,

with 1 sample site above the action level)

BDL to 36

15 (action level)

0.0

Corrosion of household plumbing systems; erosion of natural deposits

Mercury

(ppb)

BDL

no range

2

2

Erosion of natural deposits; discharge from refineries and factories; runoff from landfills; runoff from cropland

Nitrate

(ppm)

BDL

no range

10

10

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

Nitrite

(ppm)

BDL

no range

1

1

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

Selenium

(ppb)

BDL

no range

50

50

Discharge from petroleum and metal refineries; erosion of natural deposits; discharge from mines


Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

Sodium

(ppm)

22.7

17.1 to 22.7

not regulated

20 [proposed]

An element that occurs naturally in soils

Sulfate

(ppm)

27

24 to 27

not regulated

500 [proposed]

A mineral that occurs naturally in soils

Thallium

(ppb)

BDL

no range

2

0.5

Leaching from ore-processing sites; discharge from electronics, glass, and drug factories

Synthetic Organics, including Pesticides and Herbicides
Tested in 2 consecutive quarters, once every 3 years
Tested in May, July and August 2003

2,4-D

(ppb)

BDL

no range

70

70

Runoff form herbicide used on row crops

2,4,5-TP

(ppb)

BDL

no range

50

50

Residue of banned herbicide

Alachlor

(ppb)

BDL

no range

2

0

Runoff from herbicide used on row crops

Atrazine

(ppb)

BDL

no range

3

3

Runoff from herbicide used on row crops

Benzo(a)pyrene

(ppt)

BDL

no range

200

0

Leaching from linings of water storage tanks and distribution lines

Carbofuran

(ppb)

BDL

no range

40

40

Leaching of soil fumigant used on rice and alfalfa

Chlordane

(ppb)

BDL

no range

2

0

Residue of banned termiticide

Dalapon

(ppb)

BDL

no range

200

200

Runoff from herbicide used on rights of way

Di(2-ethylhexyl)adipate

(ppb)

BDL

no range

400

400

Discharge from chemical factories


Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

Di(2-ethylhexyl)phthalate (ppb)

BDL

no range

6

0

Discharge from rubber and chemical factories

Dinoseb

(ppb)

BDL

no range

7

7

Runoff from herbicide used on soybeans and vegetables

Endrin

(ppb)

BDL

no range

2

2

Residue of banned insecticide

Heptachlor

(ppt)

BDL

no range

400

0

Residue of banned termiticide

Heptachlor Epoxide

(ppt)

BDL

no range

200

0

Breakdown of heptachlor

Hexachlorobenzene

(ppb)

BDL

no range

1

0

Discharge from metal refineries and agricultural chemical factories

Hexachlorocyclopentadiene

(ppb)

BDL

no range

50

50

Discharge from chemical factories

Lindane

(ppt)

BDL

no range

200

200

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

Methoxychlor

(ppb)

BDL

no range

40

40

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

Oxamyl

(ppb)

BDL

no range

200

200

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

Polychlorinatedbiphenyls

(ppt)

BDL

no range

500

0

Runoff from landfills; discharge of waste chemicals

Pentachlorophenol, ppb

BDL

no range

1

0

Discharge from wood preserving factories

Picloram

(ppb)

BDL

no range

500

500

Herbicide runoff

Simazine

(ppb)

BDL

no range

4

4

Herbicide runoff


Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

Toxaphene

(ppb)

BDL

no range

3

0

Runoff/leaching from insecticide used on cotton and cattle

Volatile Organics

Benzene

(ppb)

BDL

no range

5

0

Discharge from factories; leaching from gas storage tanks and landfills

Carbon Tetrachloride

(ppb)

BDL

no range

5

0

Discharge from chemical plants and other industrial activities

Chlorobenzene

(ppb)

BDL

no range

100

100

Discharge from chemical and agricultural chemical factories

o-Dichlorobenzene

(ppb)

BDL

no range

600

600

Discharge from industrial chemical factories

p-Dichlorobenzene

(ppb)

BDL

no range

75

75

Discharge from industrial chemical factories

1,2-Dichloroethane

(ppb)

BDL

no range

5

0

Discharge from industrial chemical factories

1,1-Dichloroethylene

(ppb)

BDL

no range

7

7

Discharge from industrial chemical factories

cis-1,2-Dichloroethylene

(ppb)

BDL

no range

70

70

Discharge from industrial chemical factories

trans-1,2-Dichloroethylene

(ppb)

BDL

no range

100

100

Discharge from industrial chemical factories

Dichloromethane

(ppb)

BDL

no range

5

0

Discharge from pharmaceutical and chemical factories

1,2-Dichloropropane

(ppb)

BDL

no range

5

0

Discharge from industrial chemical factories

Ethylbenzene

(ppb)

BDL

no range

700

700

Discharge from petroleum refineries


Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

Styrene

(ppb)

BDL

no range

100

100

Discharge from rubber and plastic factories; leaching from landfills

Tetrachloroethylene

(ppb)

BDL

no range

5

0

Leaching from PVC pipes; discharge from factories and dry cleaners

1,2,4-Trichlorobenzene

(ppb)

BDL

no range

70

70

Discharge from textile-finishing factories

1,1,1-Trichloroethane

(ppb)

BDL

no range

200

200

Discharge from metal degreasing sites and other factories

1,1,2-Trichloroethane

(ppb)

BDL

no range

5

3

Discharge from industrial chemical factories

Trichloroethylene

(ppb)

BDL

no range

5

0

Discharge from metal degreasing sites and other factories

Total Haloacetic Acids

(ppb)

54.4

( running yearly average)

42 to 78

(individual sample sites)

60

( running yearly average)

0

By-product of drinking water chlorination

Total Trihalomethanes

(ppb)

56.1

( running yearly average)

34 to 80

(individual sample sites)

80

( running yearly average)

0

By-product of drinking water chlorination

Chloramines

(ppm)

3.3

(running annual average of monthly distribution system samples Jan., Feb. and April through Dec.)

3.0 – 3.7

(range of monthly distribution system sample averages)

 

MRDL = 4

MRDLG = 4

Water additive used to control microbes.

Chlorine

(ppm)

0.72

(average of distribution system samples in March)

No range

MRDL = 4

MRDLG = 4

Water additive used to control microbes

Tolulene

(ppm)

BDL

no range

1

1

Discharge from petroleum factories

Vinyl Chloride

(ppb)

BDL

no range

2

0

Leaching from PVC piping; discharge from plastics factories

Xylenes

(ppm)

BDL

no range

10

10

Discharge from petroleum factories; discharge from chemical factories


Unregulated Synthetic Organic Chemicals

Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

Aldicarb

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Aldicarb sulfone

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Aldicarb sulfoxide

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Aldrin

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Butachlor

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Carbaryl

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Dicamba

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Dieldrin

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

3-Hydroxycarbofuran

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Methomyl

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Metolachlor

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Metribuzin

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Propachlor

(ppb)

BDL

no range

Not regulated

Not regulated

N/A


Unregulated Volatile Organic Chemicals

Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

Chloroform

(ppb)

7.99

no range

Not regulated

Not regulated

By-product of drinking water chlorination

Bromodichloromethane

(ppb)

1.66

no range

Not regulated

Not regulated

By-product of drinking water chlorination

Bromoform

(ppb)

BDL

no range

Not regulated

Not regulated

By-product of drinking water chlorination

Chlorodibromomethane

(ppb)

BDL

no range

Not regulated

Not regulated

By-product of drinking water chlorination

Bromobenzene

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

Bromochloromethane

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Bromomethane

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

n-Butylbenzene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

sec-Butylbenzene

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

tert-Butylbenzene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Chloroethane

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

Chloromethane

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

o-Chlorotoluene

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A


Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

p-Chlorotoluene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Dibromomethane

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

m-Dichlorobenzene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Dichlorodifluoromethane

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

1,1-Dichloroethane

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

1,3-Dichloropropane

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

2,2-Dichloropropane

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

1,1-Dichloropropene

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

1,3-Dichloropropene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Fluorotrichloromethane

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Hexachlorobutadiene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Isopropylbenzene

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

p-Isopropyltoluene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

Methyl-t-Butyl Ether

(ppb)

BDL

no range

Not regulated

Not regulated

N/A


Substance and Unit Measurement

Highest Level Detected

Range Detected

Highest Level Allowed (MCL)

Highest Level Goal (MCLG)

Major Source in Drinking Water

Naphthalene

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

n-Propylbenzene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

1,1,1,2-Tetrachloroethane

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

1,1,2,2-Tetrachloroethane

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

1,2,3-Trichlorobenzene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

1,2,3-Trichloropropane

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

1,2,4-Trimethylbenzene

(ppb)

BDL

no range

Not regulated

Not regulated

N/A

1,3,5-Trimethylbenzene

(ppb)

BDL

 

 

no range

Not regulated

Not regulated

N/A

Disinfection By-product Precursors

Total Organic Carbon

(ppm)

6.68

(annual average of source water)

5.03 to 8.38

TT

N/A

Naturally present in environment.

Physical Water Quality Characteristics
The following characteristics impact the taste and appearance of drinking water.

Substance and Unit Measurement

Annual Average

Range Detected

Highest Level Allowed (MCL)

Limit
(SMCL)

Major Source in Drinking Water

Alkalinity

(mg CaCO 3/L)

38

 

 

18 to 55

Not regulated

Not regulated

N/A

Calcium

(ppm)

5.91

 

 

4.01 to 8.02

Not regulated

Not regulated

N/A


Substance and Unit Measurement

Annual Average

 

Range Detected

Highest Level Allowed (MCL)

Limit
(SMCL)

Major Source in Drinking Water

Color

(CU)

0

 

 

0 to 2

No MCL

15

N/A

Iron

(ppm)

<0.05

 

 

no range

No MCL

0.3

N/A

Manganese

(ppm)

<0.03

 

 

no range

No MCL

0.05

N/A

Ortho-Phosphorus

(ppm)

0.25

 

 

<0.10 to 0.46

Not regulated

Not regulated

N/A

pH

8.34

 

 

7.00 to 8.90

No MCL

6.5 to 8.5

N/A

Specific Conductance (umhos/cm)

170

 

 

121 to 244

Not regulated

Not regulated

N/A

Total Hardness

(mg CaCO 3/L)

26

 

 

14 to 35

Not regulated

Not regulated

N/A

Total Phosphorus

(ppm)

0.43

 

 

0.28 to 0.69

Not regulated

Not regulated

N/A

Total Solids

(ppm)

108

 

 

36 to 186

Not regulated

Not regulated

N/A

Total Suspended Solids

(ppm)

0

no range

Not regulated

Not regulated

N/A


Glossary of Terms in Table

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.

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.

SMCL - Secondary maximum contaminant level - limits set for aesthetic reasons. They are non-enforceable.

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

90 th Percentile – 90 percent of the samples were below this value. Required reporting unit for lead and copper.

BDL - Below detection level

ppm - Parts per million - equivalent to milligrams per liter. One part per million is comparable to 1 penny in $10,000.

ppb – Parts per billion – equivalent to micrograms per liter. One part per billion is comparable to 1 penny in $10,000,000.

ppt – Parts per trillion – equivalent to nanograms per liter. One part per trillion is comparable to 1 penny in $10,000,000,000.

NTU – Nephelometric Turbidity Units – Units of measurement used for turbidity or the cloudiness of water.

PCi/L – PicoCuries per liter – a measure of radioactivity in water with an activity equal to one millionth of a millionth of a curie.

MFL – Million Fibers per liter – a measure of the presence of asbestos fibers that are longer than 10 micrometers in water.

mg CaCO 3/L - Milligrams of calcium carbonate per liter water.

CU - Color units - a measurement used for color of water.

umhos/cm - Micromhos per centimeter - a measurement used for conductivity of water.

MRDLG – Maximum Residual Disinfection Level Goal – The “Level” of of 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 – Maximum Residual Disinfection Level - The “Highest Level” (MRDL) of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

 

 

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