Table of Contents

Introduction

Definitions

Drinking Water Quality: 2006 Test Results

Testing Our Drinking Water For Lead

Drinking Water Quality

For People With Special Risks of Infection

What Is Cryptosporidium?

Where Does Our Water Come From

Where Do Contaminants Come From

N.C. Source Water Assesment Program Results

Water Conservation

How You Can Get Involved In Water Quality and Water Supply Issues

INTRODUCTION

As your water service provider, Orange Water and Sewer Authority (OWASA) follows a five-part strategy to make sure you receive a safe, high quality, and reliable supply of drinking water to meet your needs:

We protect our supply through prevention of source water contamination; acquisition and preservation of critical watershed lands; and assisting local governments in implementing and maintaining effective controls on development activities within our watersheds.

We make the water safe by using high quality water treatment processes to remove potentially harmful contaminants.

We prove it’s safe by carefully monitoring the quality of the water in our reservoirs, as well as the drinking water we deliver to you and all our other customers.

We promote the wise and sustainable use and management of our local water resources through year-round conservation standards, our seasonal pricing structure, our planned reclaimed water system, and other strategies.

We do this by having a dedicated and well-trained staff of certified treatment plant operators, laboratory personnel, and other utility professionals.

In 2006, we provided more than 3 billion gallons of drinking water to the Carrboro-Chapel Hill community in compliance with State and Federal standards for safe drinking water.

Our Laboratory staff tested our drinking water for more than 100 substances, but only 13 were present at detectable levels.  As shown in this report, all 13 substances we detected were below the allowable limits of the Federal Safe Drinking Water Act (SDWA).

Regular testing shows that our drinking water is healthy and safe for almost everyone. However, people with weak or developing immune systems may need to take special precautions.  (Please see the section below titled “For people with special risks of infection...” for more information.)

DEFINITIONS

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 allow for a margin of safety.

Maximum Contaminant Level (MCL) - 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. MCLs are set at very stringent levels. A person would have to drink 2 liters (about two quarts) of water at the MCL level every day for a lifetime to have a one-in-a-million chance of having adverse health effects from many regulated contaminants.

Parts per million (ppm) - one part per million corresponds to about one minute in two years, or one penny in $10,000.  One ppm is equivalent to 1 milligram per liter (mg/L).

Parts per billion (ppb) - one part per billion corresponds to about one minute in 2,000 years, or one penny in $10 million. One ppb is equivalent to 1 microgram per liter (ug/L).

Nephelometric Turbidity Unit (NTU) - a measure of cloudiness in water. Turbidity over 5 NTU is just barely noticeable to the average person.

Action Level (AL) - the concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow under the SDWA.

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

90th Percentile – the contaminant level which 90 percent of the samples for a given water characteristic were below. The 90th percentile level is the required reporting unit for lead and copper.

Below Detectable Level (BDL) - a concentration that is below the level that can be detected with required tests using accepted laboratory methodologies.

Maximum Residual Disinfection 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 using disinfectants to control microbial contaminants.

Maximum Residual Disinfectant Level (MRDL) - the highest level of a disinfectant allowed in drinking water.  Disinfection is necessary to control microbial contaminants in drinking water.

Disinfection by-products - substances such as haloacetic acids and trihalomethanes, which are formed when chlorine or chloramines used to disinfect drinking water react chemically with organic compounds naturally present in the water from our lakes. Federal standards require public water systems to limit the levels of haloacetic acids and trihalomethanes because they could be harmful at high levels.

Disinfection by-product precursors - organic carbon compounds that can combine with disinfectants (chlorine and chloramines) to form haloacetic acids and trihalomethanes as discussed above.

Removal Ratio - measure of the effectiveness of Total Organic Carbon removal during OWASA’s treatment process. This ratio should be greater than or equal to 1.0. The Removal Ratio is the Federally required reporting unit for Total Organic Carbon.

DRINKING WATER QUALITY:  2006 TEST RESULTS

In 2006, the Laboratory staff of four people at our Jones Ferry Road Water Treatment Plant tested our drinking water more than 60,000 times for more than 100 substances in accord with State and Federal requirements. Listed below are the substances that were detected, all of which were below the regulatory limits. There were no violations of the Federal Safe Drinking Water Act or other related State and Federal standards. (Note: Please see the Definitions section above for an explanation of various terms used in the following table.)

TESTING OUR DRINKING WATER FOR LEAD

We fully comply with the Federal and State drinking water standards including all lead testing and test reporting requirements.  The Federal limit on lead in drinking water is a maximum of 15 parts per billion (ppb). Our testing results are significantly better than this standard as discussed below.

One part per billion corresponds to one penny in $10 million.

In some communities with old water systems, lead has dissolved from lead fittings or lead pipes in the network of public water mains. In the OWASA water system, however, all known lead fittings and pipes have been abandoned or removed.  

Plumbing code limits for lead in solder and fixtures were tightened in 1986. In plumbing systems built before then, lead may dissolve from pipes, solder or fixtures into drinking water.  Under certain conditions, lead can also dissolve from newly installed plumbing fixtures in a home or other building.

In accord with Federal and State standards, we test every three years for lead in tap water at 30 homes built between 1983 and 1985.  The test results from 2005, the year of our last triennial tests in the older homes, were below the detectable level of 3 parts per billion.  We also regularly monitor our drinking water as it leaves the Jones Ferry Road Water Treatment Plant.  For over 10 years, lead levels in all of those samples have been less than 3 parts per billion.

Also, in response to customers’ requests in 2006, we tested tap water for lead in 41 homes and other locations.  In 40 samples or 98% of the tests, lead was below the detectable level of 3 ppb.  In the remaining test, the lead level was 4 ppb, well below the Federal Safe Drinking Water Act limit of 15 ppb.

In the spring of 2007, we began testing water in buildings constructed in the last two years for lead contamination because of concerns about a possible link between lead contamination and new plumbing systems before a corrosion-inhibiting coating develops inside plumbing pipes and fixtures. The coating develops inside plumbing systems because OWASA adds chemicals called phosphates to drinking water during the treatment process.

We also engaged Dr. Marc Edwards of Virginia Tech to evaluate potential changes in OWASA’s water treatment process to further reduce the potential for lead contamination.

The results of the testing and evaluation work will be publicized on the OWASA Website, www.owasa.org, information provided to news media and in our customer newsletter, etc.

ARSENIC TESTING: In March and October of 2006, we tested for arsenic in our drinking water.  Arsenic was below the detectable level of 5 parts per billion.

MTBE TESTING: In March of 2006, we tested our drinking water for a substance called MTBE, which was used as an additive in gasoline.  MTBE was below the detectable level of 0.5 parts per billion.

DRINKING WATER QUALITY

All drinking water, including bottled drinking water, may be reasonably expected to contain at least small amounts of some contaminants.  The presence of these contaminants does not necessarily pose a health risk. The U.S. Environmental Protection Agency (EPA) limits the amount of certain contaminants in water from public drinking water systems. The Food and Drug Administration sets limits for contaminants in bottled water to protect public health.

ADDITIONAL CHARACTERISTICS OF OUR DRINKING WATER

• DISINFECTION WITH CHLORAMINES. We disinfect our water with chloramines, a compound of chlorine and ammonia, in all months except March, when we instead use chlorine for disinfection in accord with State requirements. Chloramines and chlorine are toxic to fish and amphibians, such as frogs. If you have fish in an aquarium that is filled with OWASA water, please contact a pet supply store for advice on how to neutralize chloramines and chlorine to protect your fish.
• OUR DRINKING WATER IS VERY SOFT. It has a low mineral content (dissolved calcium, etc.) of about 2 grains per gallon of water. This means that a small amount of soap is needed for washing dishes, clothes, your hands, etc.
• OUR WATER IS SLIGHTLY ALKALINE. On the scale of acidity to alkalinity, our water normally has a pH of about 8.3. In the month of March, we adjust the pH to about 7.4 when we temporarily use chlorine instead of chloramines to disinfect the water. The pH of our water helps make the water treatment process work effectively and helps prevent corrosion in both public water mains and private plumbing system pipes, fixtures and appliances.
• SOMETIMES OUR WATER LOOKS RUSTY, MILKY OR BUBBLY because repairs or other work that we do on the water system may stir up iron or other minerals that have accumulated in a water main, or because air may enter water mains during a repair. This can also occur when fire hydrants have been used for firefighting.  Running cold water in a bathtub, etc. for 5 to 10 minutes usually clears up the discoloration. If the water does not clear up, please contact us at 968-4421. The water should be clear before washing clothes, etc.

FOR PEOPLE WITH SPECIAL RISKS OF INFECTION

Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as people with cancer undergoing chemotherapy, people who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly people and infants can be particularly at risk of infections.

These people should seek advice from their health care providers about drinking water. Guidelines from the U.S. EPA and Centers for Disease Control and Prevention (CDC) on appropriate means to lessen the risk of infection by Cryptosporidium (please see additional information below about Cryptosporidium) and other microbial contaminants are available from the Safe Drinking Water Hotline (800-426-4791). 

To assist people with these infection risks, OWASA offers water treated with extra filtration, reverse osmosis and final disinfection with ultraviolet light. This water is available from an outdoor water vending machine on the west side of our Administration Building at 400 Jones Ferry Road, Carrboro. The cost is 40 cents per gallon. The water vending machine can fill a customer’s container of up to 5 gallons.

WHAT IS CRYPTOSPORIDIUM?

Cryptosporidium is a microscopic organism that can cause diarrhea, fever and other gastrointestinal symptoms. The organism comes from human and animal wastes and may occur in local streams and lakes. We have tested for Cryptosporidium in our reservoirs and treated water and have never detected it in our treated water or lake water.

We use a combination of source water protection and sophisticated treatment technology to minimize the potential for problems with Cryptosporidium in our drinking water supply.

Please contact us at 537-4227 if you would like to receive more information about Cryptosporidium.

WHERE DOES OUR WATER COME FROM?

                                         
The Carrboro-Chapel Hill community uses water from three surface water reservoirs:

1. University Lake, which can hold about 450 million gallons;
2. The Cane Creek Reservoir, with a capacity of about 3 billion gallons; and      
3. The Stone Quarry Reservoir, which can store about 200 million gallons. 

Water from the Cane Creek Reservoir and University Lake is pumped directly to the Jones Ferry Road Water Treatment Plant in Carrboro. Water from the Stone Quarry Reservoir can be pumped to University Lake via Phil’s Creek and, with pending improvements, to our water treatment plant. In addition to these sources, OWASA has water line connections with the City of Durham, the Town of Hillsborough and Chatham County.

By the year 2030, an expanded stone quarry about two miles west of Carrboro will become available to OWASA for water storage with an expected capacity of 2.4 to 3 billion gallons.

OWASA has an allocation of Jordan Lake storage capacity that will yield an average of 5 million gallons of water per day if needed.  If necessary in the future, we would have to either build the pumps and pipelines required to obtain water directly from the lake or we would have to partner with others to get water from Jordan Lake. However, our policy is to maximize the use of water from our existing, high quality water sources, which are protected with locally-adopted restrictions on development in our lakes’ watersheds.

WHERE DO CONTAMINANTS COME FROM?

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 land or through the ground, the water dissolves naturally-occurring minerals and, in some cases, radioactive material. Water can also pick up substances resulting from the presence of animals or human activity. Contaminants that may be present in water before it is treated include:

• Microbial contaminants such as viruses and bacteria, which may come from wastewater treatment plants, septic systems, pets, agricultural livestock operations and wildlife.
• Inorganic contaminants such as salts and metals, which may be  naturally present in water or may result from 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, stormwater runoff and residential uses, Department of Transportation, electric and gas utility operations, etc.
• 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 and stormwater runoff from paved and other impervious surfaces.
• Radioactive contaminants, which may be naturally-occurring or result from oil and gas production and mining activities, runoff from permitted or unpermitted landfills, etc.

N.C. SOURCE WATER ASSESSMENT PROGRAM RESULTS

The N.C. Department of Environment and Natural Resources (DENR), Public Water Supply (PWS) Section, Source Water Assessment Program (SWAP) has 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 to potential contaminant sources (PCSs).  The results of the assessment are available in SWAP Assessment Reports that include maps, background information and a susceptibility rating of Higher, Moderate or Lower.

The susceptibility rating of each water source for OWASA 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 in the watershed and its delineated assessment area). The assessment findings are summarized in the table below:

Susceptibility of OWASA’s Water Sources to Potential Contaminant Sources

The complete SWAP Assessment report for OWASA may be viewed on the Web at http://www.deh.enr.state.nc.us/pws/swap. To get a printed copy of this report, please mail a written request to: Source Water Assessment Program – Report Request, 1634 Mail Service Center, Raleigh NC 27699-1634, or e-mail your request to swap@ncmail.net. Please indicate your water system name (OWASA), OWASA’s public water supply number (03-68-010), and provide your name, mailing address and phone number. If you have any questions about the SWAP report, please contact the NC Source Water Assessment staff at 919-715-2633.

WATER CONSERVATION: PART OF OUR COMMUNITY’S SUSTAINABLE QUALITY OF LIFE.

Year-round water conservation requirements are in effect for OWASA customers as part of ordinances adopted by the Carrboro, Chapel Hill and Orange County governments in 2003, and as part of OWASA’s standards for service. The year-round requirements cover basic conservation practices to ensure that water is used wisely.

Additional water use restrictions go into effect when necessary due to drought conditions or other water shortages.

For information on current water supply and demand levels or on conservation requirements in effect at a given time, please contact us (Please see the “HOW TO CONTACT US” section below).

We will be glad to mail you our Water Conservation brochure with information on some of the best ways to conserve water indoors and outdoors, and on the year-round conservation standards.

Conservation saves water and dollars-- and energy.
 
WATER TREATMENT SYSTEM

• Raw water from University Lake or the Cane Creek Reservoir is pumped to our Jones Ferry Road Water Treatment Plant.
• The water enters our plant through the “headworks” facility, where non-toxic chemicals (fine powdered carbon and alum) are added to make solid particles clump together and to improve the taste and odor of the water.
• Water then flows to either a “pulsator” or sedimentation basins, which allow time for solids to settle out of the water.
• As water flows to filters, a liquid form of chlorine (bleach) is added for initial disinfection.
• Water flows downward through filters with layers of sand and anthracite coal, where additional particles are removed from the water.
• The water enters the post-treatment stage, where we add fluoride for dental health, and a chemical to set the pH (acidity/alkalinity) at the right level.
• The water flows to our 1.5 million gallon “clearwell” holding tank for temporary storage. Ammonia is added to the water and the ammonia combines with chlorine to form “chloramines” to further disinfect the water. (Please see the part of this report on “Additional Characteristics of our Water” for important information about chloramines and fish in aquariums.) Millions of gallons of water are pumped each day to our elevated water storage tanks.
• Our elevated tanks help to maintain water pressure so that treated drinking water can be delivered to your tap through our 406 miles of public water mains.  Those tanks also ensure that a sufficient supply of water is available at a given time to fight fires and meet peak demands.

HOW YOU CAN GET INVOLVED IN WATER QUALITY AND WATER SUPPLY ISSUES

You can get involved in water resource issues at the local, State and national levels in several ways.

• Becoming informed is the first step in being an effective participant.
• You can learn about water and water resource issues from news media; books in the library; Websites such as those of the U.S. Environmental Protection Agency, American Water Works Association and other organizations; and by contacting OWASA (telephone: 968-4421; Website: www.owasa.org; e-mail: webmaster@owasa.org).
• Expressing your views at public meetings, by contacting public officials, etc. is important when improvements, new policies and standards affecting water quality and watershed protection are needed or proposed.

We invite you to attend and participate in meetings of the OWASA Board of Directors, which makes decisions on plans and policies and adopts the annual budget for our water and wastewater services. The OWASA Board meets at 7:00 pm on second Thursdays of most months in the Community Room on the lower floor of the OWASA Administration Building, 400 Jones Ferry Road, Carrboro; and on fourth Thursdays in the Council Chamber at the Chapel Hill Town Hall. On fourth Thursdays, OWASA Board meetings are televised live on channel 18 of the cable television systems serving Chapel Hill and Carrboro.

FOR MORE INFORMATION

If you have any questions about this report or concerning your water utility, please contact our Water Treatment Plant Laboratory Supervisor at (919) 537-4227; or our Water Supply and Treatment Manager at (919) 537-4232. We appreciate the opportunity to respond to any questions you may have and we welcome your feedback about your drinking water, or any other services you receive from OWASA.

Here’s how you can contact us:

Orange Water and Sewer Authority
Public Water Supply No.: 03-68-010
 400 Jones Ferry Rd., Carrboro, NC 27510
Telephone: (919) 968-4421    Fax: (919) 968-4464   
E-mail: webmaster@owasa.org   Website: www.owasa.org

OWASA is the public, non-profit, community-owned water and sewer agency serving the Carrboro-Chapel Hill community.

EPA’s Drinking Water Hotline: (800) 426-4791

This report on the quality of our drinking water in 2006 was distributed in the spring of 2007.