Water Quality Report 2020

Winston-Salem/Forsyth County Utilities drinking water meets all water quality standards

Winston-Salem/Forsyth County Utilities operates three water treatment facilities drawing water from both the Yadkin River and Salem Lake. Together, these water treatment facilities can produce up to 91 million gallons of drinking water per day. The Neilson and Swann Water Treatment Plants can treat 48 and 25 million gallons per day, respectively, from the Yadkin River. The Thomas Water Treatment Plant can treat 18 million gallons per day from Salem Lake and the Yadkin River.

For 2020, as in previous years, these treatment facilities have met or surpassed all state and federal standards for drinking water quality. This accomplishment reflects the quality and dedication of the employees who work year-round to provide adequate supplies of safe drinking water.

This report includes details about the sources of your drinking water, how it is treated, what it contains and exactly how it compares to state and federal standards. We provide this updated information annually because we are committed to delivering top-quality drinking water to our customers. 

Print version: Water Quality Report 2020 (PDF)
Reporte de calidad de agua 2020  Versión impresa: Reporte de calidad de agua 2020 (PDF)
For more non-English translations, click Select Language button at bottom right.

Flowing through history…

George Washington portrait

Did you know?

In 1774, the Moravians of Salem began work on one of the nation’s first water systems. Water was delivered through bored-out logs joined end-to-end, a design praised by President WaOld Salem wooden pipeshington during his 1791 visit.

empty water bottle with slash

Quench Your Thirst!

Our water is safe and satisfying, so skip the bottle and save big $$$!

Protecting Our Water Sources

Sources of both tap and bottled drinking water include rivers, lakes, 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. Water can also pick up substances resulting from the presence of animals or from human activity.

Contaminants that may be present in source water include:

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

• Inorganic contaminants, such as salts and metals, which can occur naturally or result from urban storm water runoff, industrial or wastewater discharges, oil and gas productions, mining or farming.

• Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban storm water 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 come from gas stations, urban storm water runoff and septic systems.

• Radioactive contaminants which can occur naturally or as a result of oil and gas production and mining activities.

To ensure that tap water is safe to drink, the Environmental Protection Agency limits the amount of certain contaminants in water provided by public water systems. Food and Drug Administration regulations establish limits for contaminants in bottled water, which must 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 the water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the EPA’s Safe Drinking Water Hotline at 800-426-4791.

North Carolina Source Water Assessment

The North Carolina Department of Environmental Quality (DEQ), Public Water Supply (PWS) Section, Source Water Assessment Program (SWAP) conducted assessments for all drinking water sources across North Carolina. The purpose of the assessments was to determine the susceptibility of each drinking water source (well or surface water intake) to Potential Contaminant Sources (PCSs). The results of the assessment are available in SWAP Assessment Reports that include maps, background information and a relative susceptibility rating of Higher, Moderate or Lower.

The relative susceptibility rating of each source for the City of Winston-Salem (PWSID 0234010) was determined by combining the contaminant rating (number and location of PCSs within the assessment area) and the inherent vulnerability rating (i.e., characteristics or existing conditions of the well or watershed and its delineated assessment area). The assessment findings are summarized in the table below:

Source Water Assessment Program Results Summary

Salem LakeModerateHigherHigher
Yadkin River (Idols Dam)HigherModerateHigher
Yadkin River (PW Swann Water Treatment Plant)HigherLowerModerate

Table 2 of SWAP Report for Winston-Salem

It is important to understand that a susceptibility rating of “higher” does not imply poor water quality, only the system’s potential to become contaminated by PCSs in the assessment area.

The complete SWAP Assessment report for the City of Winston-Salem may be viewed on the Web at: ncwater.org/?page=600. Please indicate your system name (Winston-Salem, City of) and number (0234010). Note that because SWAP results and reports are periodically updated by the PWS Section, the results available on this web site may differ from the results that were available at the time this report was prepared.

If you are unable to access your SWAP report on the web, you may mail a written request for a printed copy to:
Source Water Assessment Program - Report Request
1634 Mail Service Center
Raleigh, NC 27699-1634
or email requests to swap@ncdenr.gov. Please indicate your system name (Winston-Salem, City of), number (0234010), and provide your name, mailing address and phone number. If you have any questions about the SWAP report please contact the Source Water Assessment staff by phone at 919-707-9098.

Treated Water Quality

The following substances were detected in Winston-Salem/Forsyth County Utilities public water supply during the 2020 calendar year.

Regulated at the Treatment Plant

SubstanceHighest Level Allowed (EPA  MCL1)Ideal Goals
RANGe of DetectionAverage Level DEtectedSource
Barium, ppb42000200013.0 - 21.016.0Natural geology; drilling operations; metal refinery wastes
Fluoride ppm54.064.00.01 - 1.010.79Erosion of natural deposits; Water additive, promotes strong teeth
Orthophosphate, ppmN/A0.50 - 5.00120.37 - 1.010.86Water treatment additive to prevent pipe corrosion
Total Organic Carbon, ppmTreatment Technique7N/A0.79 - 1.531.03Naturally present in the environment
Turbidity, NTU8Treatment Technique 9N/A0.02 - 0.350.05Soil erosion

Regulated in the Distribution System

Range of dEtectionAverage LEvel DEtectedSource
Total Trihalomethanes, ppb80 LRAA100.018.2 - 98.853.4Byproducts of drinking water disinfection
Total Haloacetic Acids (5), ppb60 LRAA100.0

16.4 - 54.8

32.2Byproducts of drinking water disinfection
Chlorine, ppm4.04.00.04 - 1.860.97Water treatment additive for disinfection
Total ColiformsLess than 5% positive0.0ND - 0.54%110.05%

Naturally present in the environment

Unregulated Substances at the Treatment Plant - Point of Entry

Geosmin, ppt3Not RegulatedND - 7.13.1Byproduct of algae growth13
2-methylisoborneol, pptNot RegulatedND - 5.81.6Byproduct of algae growth

Unregulated Substances at the Treatment Plant - Source Water

Geosmin, pptNot RegulatedND - 7.72.8Byproduct of algae growth
2-methylisoborneol, pptNot RegulatedND - 40.48.1Byproduct of algae growth


1 Maximum Contaminant Level (MCL) - The highest level of a contaminant that is allowed in drinking water.

Maximum Contaminant Level Goal (MCLG) - The level of a contaminant in drinking water below which there is no known or expected risk to health.

3 ppt - One part per trillion. - (For example, one penny in $10,000,000,000.)

4 ppb - One part per billion. - (For example, one penny in $10,000,000.)

5 ppm - One part per million. - (For example, one penny in $10,000.)

6 The EPA’s maximum contaminant level for fluoride is 4.0 mg/L, however the State of North Carolina has established a maximum contaminant level of 2.0 mg/L.

7 Treatment technique - Treatment technique for total organic carbon was complied throughout 2019.

NTU - nephelometric turbidity unit, a measure of the cloudiness of water.

9 Treatment technique - 95% of the measurements taken in one month must be below 0.3 NTU. Turbidity treatment technique was complied with throughout 2020.

10 Locational running annual average - average of last four quarters of samples collected at each location at 12 monitoring sites.

11 1 TC positive sample out of 185 in August 2020 = 0.54%

12 A corrosion study was conducted that determined the ideal orthophosphate range for reducing lead and copper corrosion in our system was between 0.50 - 5.00 ppm.

13 These compounds are created by algae in raw water that can cause an earthy/musty taste or odor in drinking water. While some people may find this unpleasant, there are no known negative health impacts associated with their consumption.

ND = not detected

Physical & Mineral Characteristics - Calendar Year 2020

ConstituentAnnual Range DetectedAnnual Average
Alkalinity, ppm15.00 - 26.0020.60
Aluminum, ppm0.006 - 0.0270.011
Calcium, ppm3.21 - 4.583.90
Carbon Dioxide, ppm1.00 - 9.503.40
Chlorine, ppm0.75 - 1.821.42
Conductivity, micromhos/cm78.80 - 130.4096.20
Copper, ppmND - 0.0210.002
Hardness, ppm10.0 - 26.017.6
Iron, ppmND - 0.011<0.010
Lead, ppmND - 0.001<0.001
Magnesium, ppm1.17 - 1.721.42
Manganese, ppmND - 0.0110.001
Nickel, ppmND - 0.001<0.001
pH, Standard Units6.80 - 8.307.50
Phosphate, ppm0.68 - 1.040.86
Potassium, ppm1.34 - 3.241.78
Silica, ppm3.78 - 16.9010.50
Sodium, ppm7.94 - 16.4010.20
Zinc, ppm0.173 - 0.2730.215

 ND = not detected

Cryptosporidium sp.
This is a microscopic organism that, when ingested, can cause diarrhea, fever and other gastrointestinal symptoms. The organism occurs naturally in surface waters (lakes & streams) and comes from animal waste. Cryptosporidium sp. is eliminated by an effective treatment combination of coagulation, sedimentation, filtration and disinfection.

We have completed two rounds of 24-month sampling at all of our water sources and have not detected any cryptosporidium. In addition, Cryptosporidium sp. has never been detected in our treated drinking water.

Special Concerns
Some people may be more vulnerable to contaminants in drinking water than the general population. People whose immune systems have been compromised – such as people 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 for infections.

These people should seek advice about drinking water from their health care providers. Environmental Protection Agency and Centers for Disease Control guidelines on appropriate means to lessen risk of infection by Cryptosporidium sp. and other microbiological contaminants are available from the Safe Drinking Water Hotline at 800-426-4791.

En Español
Si desea recibir una copia de este reporte en Español o si tiene preguntas con respecto a la calidad del agua que consume, por favor comuniquese con el departamento the servicios públicos durante las horas de trabajo, el teléfono es 336-727-8000 o visite cityofws.org/wqr2020espanol.

Lead Exposure from Water

Elevated levels of lead in drinking water can cause serious health problems, especially for pregnant women and young children. Lead in drinking water comes primarily from materials and components associated with service lines and home plumbing.

Winston-Salem/Forsyth County Utilities 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 are concerned about lead in your water, you may wish to have your water tested by calling City Link 311 (336-727-8000). Information and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline at 800-426-4791 or epa.gov/ safewater/lead.

Regulated at the Consumers Tap - 2019 Compliance Samples                                                         

SubstanceHighest Level Allowed (EPA MCL1)Ideal Goals (EPA MCLG2)Number of Sites SampledNumber of Sites Above the Action Level90th Percentile Concentration, ppb
Lead, ppb315.0 (action level4)0.0531<3.0
Copper, ppb1300.0 (action level)1300.0530<50.0

Unregulated at the Consumers Tap - 2020 Customer Samples                                                        

Lead, ppb15.0 (action level)0.0170<3.0
Copper, ppb1300.0 (action level)1300.0170<50.0

Source (both lead and copper): Corrosion of household plumbing; erosion of natural deposits


1 Maximum Contaminant Level (MCL) - The highest level of a contaminant that is allowed in drinking water.

2 Maximum Contaminant Level Goal (MCLG) - The level of a contaminant in drinking water below which there is no known or expected risk to health.

3 ppb - One part per billion. - (For example, one penny in $10,000,000.)

4 Action Level - The concentration of a contaminant that triggers treatment or other requirement that a water system must follow. Action levels are reported as the 90th percentile, which is the concentration that 90 percent of the locations sampled falls below. In 2019, our 90th percentile values were lead <3.0 and copper 0.56 ppb.

ND= not detected

WSFC Utilities logo - 2019

Winston-Salem/Forsyth County Utilities is governed by the WSFC Utility Commission, which meets on the second Monday of each month. Meeting details at cityofws.org/utilitycommission. For questions about this report or the quality of our drinking water, call City Link 311 or 336-727-8000.

Mayor: Allen Joines
Denise D. Adams, Mayor Pro Tempore, North Ward
Barbara Hanes Burke, Northeast Ward
Robert C. Clark, West Ward
John C. Larson, South Ward
Jeff MacIntosh, Northwest Ward
Kevin Mundy, Southwest Ward
Annette Scippio, East Ward
James Taylor, Jr., Southeast Ward
City Manager: Lee D. Garrity

David R. Plyler, Chair
Don Martin, Vice Chair
Fleming El-Amin
Ted Kaplan
Richard V. Linville
Tonya D. McDaniel
Gloria D. Whisenhunt
County Manager: Dudley Watts, Jr.

Randall S. Tuttle, Chair
L. Wesley Curtis, Jr., Vice Chair
Harold E. Day
Tom Griffin
Yvonne H. Hines
Duane Long
Hugh W. Jernigan
Chris Parker
Donald R. Stewart
Charles Wilson
Allan Younger

Produced by Winston-Salem/Forsyth County Utilities
P.O. Box 2511
Winston-Salem, N.C. 27102

City Link 311 or 336-727-8000

PWSID 0234010

Copies of this report are available at cityofws.org/waterquality2020 or cityofws.org/wqr2020espanol..

water surface border