Water is necessary for life. Everyone knows that.Yet sometimes, we might take it for granted.Turn on the tap, and it’s there!

But would you dip your cup into the lake and drink it? Probably not. There’s still a necessary process that water must undergo in order to get from the lake to your glass. We at OWASA proudly manage that process for you and the entire Carrboro-Chapel Hill community.

On the lake, in the field, at the lab and in the office, our diverse team works to reliably deliver high-quality drinking water, efficiently and sustainably. Follow the links below to learn more about how we deliver water to you and your loved ones.

Where Does My Water Come From?

The warm morning sun shines through the tops of pines and hardwoods, down onto a rippling mirror of lapping waves. A choir of cicadas whirs in a rising song. Fish pop at insects landing on the lake surface. An osprey returns to its nest in an old oak tree nearby. This is where your water comes from.

OWASA’s water supply originates as rain in the watersheds of Cane Creek Reservoir and University Lake. A watershed is an area where all water eventually drains into the same place. Cane Creek Reservoir and University Lake are themselves within the watershed of the Haw River, itself in the Cape Fear River basin, which runs southeast to its delta near Wilmington before spilling into the Atlantic Ocean. About 90% of our reservoirs’ watersheds are in Orange County; the remaining 10% lay in Alamance and Chatham counties.

Within these watersheds, water is stored in three reservoirs:

Cane Creek Reservoir

Cane Creek Reservoir, about 9 miles west of Carrboro, can store about 3 billion gallons from its 32-square mile watershed and has a surface area of about 540 acres. More than 3,000 acres of watershed land is either owned by OWASA or protected through conservation easements.

University Lake

University Lake. just west of Carrboro. can store about 450 million gallons from its 30-square mile watershed and has a surface area of about 200 acres.

Quarry Reservoir

Quarry Reservoir, within the University Lake watershed about 3 miles west of Carrboro, can store around 200 million gallons. Beginning around 2030, the reservoir is expected to expand and provide a capacity of at least 2.2 billion gallons; filling the expanded quarry will take a few years.

The Cane Creek Reservoir, University Lake, and Quarry Reservoir system combined can support an average yield of about 10.5 million gallons per day (mgd) during severe drought conditions; current demand is approximately 7 mgd. OWASA also has an allocation of 5% of Jordan Lake’s water-supply storage capacity, which can yield about 5 to 6 mgd.

If you’d like information about your water supply, including future plans, please refer to our Long-Range Water Supply Plan.

How Does OWASA Treat My Water?

The cleanliness of America’s water supplies is a true masterpiece of public health. In fact, water treatment was highlighted by the Centers for Disease Control as one of the top achievements of the 20th Century, leading to a sharp decrease in diseases ranging from typhoid to chronic tooth decay.

While water in our local reservoirs is very clean, it requires treatment before it is drinking-water quality, just like water supplies anywhere else in the country.

“We take water from the lake, and while we do our best to protect the area around the reservoirs, it’s still not ready for drinking,” says Katie Harwell, OWASA’s Jones Ferry Rd. Water Treatment Lab Supervisor. “There’s algae growing in it, ducks paddling around in it, silt floating in it. And we make it safe and aesthetically pleasing.”

Water is pumped from the reservoirs to the water treatment plant in Carrboro; the plant can treat up to 20 million gallons per day (mgd).There, any impurities or contaminants affecting water quality — bacteria, microorganisms, algae, silt, clay particles and the like — are removed through a series of physical and chemical processes.


The treatment process can be divided into four steps. Click through to see the stage of this process:

Mixing at Water Treatment Plant

1. Mixing

The mixing step is actually two processes performed in quick succession: coagulation and flocculation. While these terms sound very technical, the concept behind the first step of the treatment process can be explained quickly and simply.

Coagulation refers to removing negative charge from particles present in lake water by adding a substance that makes organic compounds stick together. When combined with slow, steady mixing, this initial process leads to flocculation. Flocculation is the binding together of contaminants into larger particles, called “floc”, making it easier to remove these impurities from drinking water.

Clarification at Water Treatment Plant

2. Clarification

Unwanted particles that accumulated during flocculation become suspended in the treated water. This water then moves into settling basins, where it undergoes the process of clarification. Clarification, or sedimentation, is like silt formation in lakes and rivers, in that the larger particles settle out of the water — that is, they sink to the bottom.

Filtration at Water Treatment Plant

3. Filtration

Any of the tiniest particles still remaining in the water following the sedimentation process are removed during filtration. Filtration is exactly what it sounds like: Water sinks through a barrier — first, a layer of anthracite, then through densely-packed sand — trapping unwanted particles.

Jones Ferry Road Water Treatment Plant

4. Disinfection

The final step in the treatment process is disinfection. Disinfection is the eradication of bacteria, viruses and other pathogens to reduce waterborne illnesses. Primary disinfection actually begins during the filtration process; free chlorine, in the form of liquid bleach, is added to the sand in order to kill microorganisms. The water then passes into a tank called the clearwell, where we apply additional chlorine as needed to ensure proper disinfection. As the water leaves the plant, we carefully add a bit of ammonia to the water, which combines with the chlorine to form “chloramines,” our secondary disinfectant. Chloramines and chlorine in your drinking water is safe to drink.

If you would like more information about our drinking-water treatment processes, view our FAQs below or call our lab staff at (919) 537-4228.

Water Treatment FAQs

We know the science of water can be a bit complex. Here are some answers to your most-frequently asked questions.

Who sets the standards for the quality and safety of drinking water?

Both Federal and State agencies set the standards. In accordance with the Federal Safe Drinking Water Act, the Environmental Protection Agency (EPA) issues national standards for the quality of drinking water and how it is tested. For more information, please visit the EPA’s water quality website. The State of North Carolina sets some additional drinking water standards related to water quality testing procedures and regulatory limits. State regulations can only be more stringent than Federal regulations.

Who tests the quality of OWASA’s water? How?

The staff at our water treatment plant laboratory, which is certified by the State, monitors our drinking water quality by doing about 50,000 tests each year. Using state-of-the-art equipment and instruments, our laboratory staff tests for more than 150 substances in drinking water. The results of these analyses are published in our annual Water Quality Report Card, which is distributed throughout our service area. While our laboratory staff does most of the water testing required by State and Federal regulations, private laboratories approved by the State do some specialized testing for OWASA.

In addition to testing our drinking water, we monitor the water quality in our reservoirs, as water goes through the treatment process and through our distribution system of more than 390 miles of public water pipes in the Carrboro-Chapel Hill community.

Is a home filter needed for OWASA drinking water?

OWASA does not recommend removing disinfectants, except for special uses including dialysis and in aquariums, because disinfectants kill bacteria. Maintaining a disinfectant residual in our water pipes and your home plumbing helps prevent bacterial regrowth.

A home filter may be necessary if you have a weak immune system, allergies, special medical needs or sensitivities that you can address with additional filtering. For home dialysis or other specialized medical uses, please follow the advice of health care providers and medical equipment manufacturers regarding water filtration or treatment.

Otherwise, OWASA customers do not need to treat their drinking water at home to make it safe. Certain home water-treatment units can improve water’s taste. If you own or plan to buy a home water treatment unit, we recommend carefully researching the product so that you will understand its capabilities, limitations, benefits and ongoing costs for filter replacement, maintenance and more. Please note: If a home water-treatment filter is not changed regularly, it may stop working as intended and could become a source of bacterial growth or other contamination.

What should I do if I want OWASA to test the OWASA drinking water in my home or business?

If you’d like a lab analyst to collect a water sample from your home or business, please contact the OWASA Laboratory Staff at 919-537-4228, or send an email to WTPLaboratory@owasa.org to schedule an appointment. Typically, we schedule water sampling at customers’ homes or businesses on Mondays through Thursdays between 10 a.m. and 12 p.m. We test the pH, chlorine, and turbidity (clarity) of our water, as well as for bacteriological indicators. We also provide lead and copper testing of our water for our customers. To request a lead and copper sample kit, contact the lab staff at the number or email provided above. There are no fees for these services.

Who tests water from private wells?

The Orange County Health Department can test your well water. If you live in Orange County and wish to have your well water tested, please contact the Wells Division of the Orange County Health Department at 919-967-9251 and ask for the Wells Division, or visit their website for more information.

Is the chloramine and chlorine in my water safe to drink?

Yes. OWASA water treated with chloramines or chlorine is safe to drink. We carefully control the disinfectant levels in our water to meet the standards in the Federal Safe Drinking Water Act, and we routinely monitor the chloramine and chlorine levels throughout the water system.

My water smells and tastes like chlorine. How can I get rid of the chlorine?

During the month of March, we use chlorine as both our primary and secondary disinfectant. As a result, your water may have a slight tinge of chlorine, either in taste or odor. OWASA does not recommend removing chlorine, except for special uses like dialysis and in aquariums, because chlorine kills bacteria. However, we recognize that some customers may wish to remove chlorine due to sensitivities. If you would like to remove the chlorine from the drinking water, you may do so with several methods, including:

  • filtering the water with a pitcher featuring an activated-carbon filter,
  • letting the water sit uncovered in the refrigerator for a day or so,
  • boiling the water for one minute to cause the chlorine to evaporate, or
  • adding a few lemon slices to a pitcher of water; acids in lemon naturally dechlorinate the water.

Why is chlorine used as the only disinfectant during the month of March?

The Department of Environmental Quality requires annual, full chlorination of water systems for a few reasons. As our drinking water is disinfected but not completely sterile, bacteria can still exist and grow in our system. Bacteria can contribute to nitrification, or the breakdown of ammonia found in the chloramines we use as the secondary disinfectant most of the year, leading to less-efficient disinfection throughout the system. Also, biofilms can form in our pipes. Chlorine is especially effective at preventing these things from happening. Finally, we flush the water distribution system in March, so consider the chlorination as another bit of spring cleaning.

How can I remove chloramines?

OWASA does not recommend removing chloramines, except for special uses including dialysis and in aquariums, because chloramines kill bacteria. However, we recognize that you may wish to remove chloramines because of sensitivities. To effectively reduce chloramine levels in drinking water, select a filter, filtration system, or treatment system that has been tested specifically for chloramine reduction under NSF/ANSI Standard 042.

Can water with chlorine or chloramines affect rubber plumbing components, such as toilet flappers?

All rubber components have useful lifetimes and require periodic replacement. For example, expansion tanks for hot water heaters typically have a five-year warranty. Selecting rubber plumbing components intended for use in water treated with chloramines will increase the useful lifetime of toilet flappers, supply lines and flexible connectors or hoses. When replacing rubber components, be sure to choose a model designed for use in water systems with chloramines. For example, PVC is generally considered non-reactive to both chloramines and chlorine itself, so connectors and supply lines with PVC cores are more resistant to these disinfectants than others. Also, some materials have been tested specifically for chloramine resistance and are labeled as such. Note that “chemical-resistant” and “chlorine-resistant” are not the same as chloramine-resistant.

Do chloramines contribute to dezincification of brass?

Dezincification is the selective release of zinc from brass, and it can affect brass with high zinc content. Direct connections of different types of metals, water velocity, water chemistry and higher temperatures can facilitate dezincification of susceptible brass. However, OWASA drinking water is classified as non-aggressive with respect to corrosion like dezincification, on the basis of its chloride level, alkalinity and pH. Current research has not found chloramines to contribute to dezincification of brass; as a matter of fact, a 2011 study of chemical and physical factors associated with real plumbing systems found that chlorine and chloramines slightly inhibit dezincification.

Do chloramines cause the release of lead from brass or other materials?

Some plumbing fixtures and fittings within homes may contain lead, especially in older homes. Fittings and fixtures containing lead should be considered a potential source of lead in drinking water. However, current research has not found a relationship between chloramines and release of lead from brass or other metals. Moreover, OWASA has an effective corrosion control program, which includes adding a phosphate compound to inhibit the release of lead from household plumbing. The phosphate forms a protective coating inside pipes and fixtures, controlling corrosion in our public water system and in private plumbing.

What precautions should kidney dialysis patients take before using our tap water?

Both chlorine and chloramines must be removed from water used in kidney dialysis machines. Medical clinics performing dialysis are responsible for purifying the water entering dialysis machines. We have informed the overall community, including dialysis clinics and medical facilities, about the need to remove chloramines from water used in dialysis machines. We also provide annual notices about our switch to chlorine during the month of March. Customers with home dialysis equipment should contact the equipment manufacturer or dealer for information about whether any adjustments in operation or maintenance of the equipment are needed.

Do I need to treat my tap water before I use it in an aquarium or herpetarium?

Yes. Unfortunately, chlorine and chloramines in our drinking water are toxic to fish and amphibians. We disinfect our water with chlorine in the month of March and with chloramines in the rest of the year; these two types of disinfectants must be dechlorinated differently. Chemical treatment or additives are available at most pet stores. For more information on treating water for your aquarium, please contact your pet or fish supply store.

How Does Water Get to Me?

Your water comes from reservoirs, then undergoes an extensive treatment process, but how does it travel from the treatment plant to your drinking glass?


square miles


miles of water distribution pipes




fire hydrants

The OWASA distribution system covers about 35 square miles and consists of about 390 miles of water distribution pipes, over 12,000 valves and more than 2,000 fire hydrants. Local demand for water remains steady at about 7 million gallons per day (mgd).

Drinking water is pumped from the water treatment plant on Jones Ferry Rd. in Carrboro to elevated storage tanks, like the Carolina blue water tower on Manning Dr. in Chapel Hill, through our system of pipes. The pipes also lead to your home or business, but the water pressure necessary to keep water flowing to your home is maintained by simple physics: the weight of water stored in our water towers. Pumping stations maintain water pressure throughout the system, all the way to your home, and when you open your tap or faucet, the water streams through. It’s as simple as that!

System Resiliency

As you can imagine, a public water system undergoes some stress in its service to the community. Major storms, debris, root growth, accumulated fats and other stressors can impact some the hundreds of miles of pipes constituting the community’s water and wastewater system. Our team works diligently to maintain and upgrade this critical infrastructure.

Nearly 50% of customer rates fund OWASA’s Capital Improvements Program. Each year, we invest $20 million in strengthening water and wastewater infrastructure to increase system resiliency — upgrading pipes, pumps and much more. In other words, most of your water bill goes directly to making your water better.

Moreover, we subject the many facets of our system to routine maintenance, inspection and exercise. One of the key examples is our valve maintenance program. We maintain 12,000 water-distribution valves across the Carrboro-Chapel Hill community. These valves, connecting our hundreds of miles of underground pipes, constitute one of the most important parts of our distribution system. Quite like the kitchen tap or shut-off valve in your home or business, we can use these valves to shut off water service to a portion of the system and perform localized repairs.

For more information on the resilience of the OWASA system, contact us with any questions or concerns you may have by emailing info@owasa.org.

How Our Water Meters Work

Our water meter is located within a small box in the ground, usually at or near the boundary between your property and the street right-of-way. The OWASA meter registers the amount of water use in your home or business.

Advanced Metering Infrastructure (AMI) technology in your meter uses a small battery-powered communications device to read and transmit a low-powered radio signal to a nearby collector. The collector then transmits the meter reading to our office in Carrboro. This allows water-use data to be more available to you and OWASA on a daily basis and eliminates the need for someone to drive to your home to read your water meter.

Our meter does not indicate the type of water use — unless the meter is for irrigation-only service — or where water goes after passing through the meter. Normally, we use the readings from your water meter to determine the volume of your wastewater use. In other words, we assume the volume of water discharged into the wastewater system equals the amount of drinking water that came through the meter to your location. However, for individually-metered residential customers, the maximum charge for wastewater use is for 15,000 gallons per month.

Please keep the meter area clear of garbage cans, boxes, yard waste, vehicles and other possible obstructions. Please do not install fences or plant trees or shrubs which would restrict access to our meter. We appreciate your cooperation!

My Plumbing System

When it comes to your plumbing system, a basic understanding can be a big help. You can save water, time, money and inconvenience by understanding key items about your plumbing system and its simple maintenance needs.

Emergency Shut-Off Valve

Quite like the system of distribution valves running below your feet, there are valves within your home or business regulating water pressure and service. A crucial one to know about is your shut-off valve. It performs a duty you might expect: In case of a major leak, you can use it to shut off service to your premises, saving water from being wasted and preventing possible damage.

Typically, the shut-off valve is located within a closet, crawlspace or basement, relatively close to the OWASA meter for your property. We encourage you to clearly mark the shut-off valve in your plumbing system, or, if your property doesn’t have one, to install a shut-off valve if one is not in place.

We recommend that you determine which pipes, faucets and other fixtures are affected when you use the shut-off valve and which pipes (if any) are not. For example, a shut-off valve will not turn off the water flow to an outdoor spigot and piping, which are “upstream” of the valve. As a basic check, you can turn the shut-off valve to the Off position, then see which faucets and fixtures are affected. Most shut-off valves are closed by turning the wheel or lever clockwise; turn it counter-clockwise to open the valve. You may also ask a plumber to determine what parts of your system are affected by the shut-off valve.

Here’s a printable tag you can use to clearly mark your emergency shut-off valve.

Pressure-Reducing Valve (PRV)

Another important valve to know about with regards to your plumbing system is the pressure-reducing valve (PRV). A PRV is a device that reduces and stabilizes the water pressure in a home, business or other building, typically between 35 and 60 pounds per square inch (psi).

Lower pressure helps conserve water, and plumbing pipes, hoses and fixtures tend to last longer and experience fewer leaks if they are used at lower pressures. Reducing water pressure is also important because the pressure in some of our public water pipes can be much higher than 60 psi.

It’s simple physics: The pressure in our water pipes results from the weight of water in elevated storage tanks throughout the Carrboro-Chapel Hill community. The fact that water is surprisingly heavy contributes to water pressure: A cubic foot of it (7.48 gallons) weighs about 62 pounds, and we have a storage capacity of roughly 8 million gallons. This means the greater the difference in elevation of water in our tank compared to the elevation of our pipes serving your building, the greater the pressure.

Differences in Carrboro-Chapel Hill’s topography lead to variable pressures around the community. The elevation of land here is typically higher in the west and lower in the east; thus, water pressures tend to be higher in east Chapel Hill than on the west side of Carrboro. And those pressures vary quite a bit: Water pressure in neighborhoods on hills or ridges may be as low as 35 psi, while pressures in low-lying areas may exceed 150 psi.

Therefore, the water pressure in your private plumbing system can be determined in one of two ways: Either by the elevation of your building in relation to a storage tank, or by a PRV. Under the State plumbing code, a PRV is required if the pressure in the OWASA water main serving a house or building is above 80 psi. Even if not required, a PRV may be a good idea if you need to adjust or limit pressure in your plumbing system.

If you’d like to find out if you have a PRV, you could try to locate it yourself. PRVs are usually installed at a point near where your private water-supply line from our water meter comes into the building. For example, if your residence has a crawlspace, the PRV may be installed just inside the foundation wall; if there is no crawlspace, the PRV may be in a closet near the front of the premises.

If you’re noticing fluctuations in water pressure, a failing PRV might be the culprit. Like other devices, PRVs can fail due to age and other factors. As a first step, we invite you to call us at 919-968-4421 to schedule a free pressure check. If repair or replacement of your PRV is needed, we recommend having a licensed plumber advise you about the type of PRV needed and install it.


The P-trap is a plumbing device that prevents odorous gas in plumbing drains and sewers from rising up through a toilet, sink or floor drain into a home or business. Despite the name, though, a P-trap is a U-shaped section of pipe that holds a bit of water serving as that barrier.

Sewer gas is formed in the natural breakdown of solids in wastewater due to bacterial activity. Sewer gas may not only have an offensive odor; it may also include methane, which is potentially combustible.

P-traps are built into toilets and are required in plumbing drains under State building code. If you smell sewer gas inside a home or other building, a faulty or dry P-trap may be the cause.

If a drain, sink or toilet is not used for a long time, or if there is a leak in the P-trap, it may go dry and allow sewer gas to rise into a home or other building. To refill a P-trap, flush the toilet, pour water in the floor drain or run water down the sink. Then, check to make sure the sewer gas has stopped coming into the building. If sewer gas continues, there may be a leak or loose connection at the P-trap, so you may need help from a plumber.

Water and Sewer Laterals

When we refer to laterals, we’re talking about the privately owned and maintained service pipes carrying water to and wastewater from a building. Typically, they run perpendicular to the street right-of-way. Private-property owners are responsible for maintaining laterals.

If there is a leak in water lateral, the property owner is responsible for repairing it. Property owners are responsible for repairs, clearing debris, roots, grease and other blockages from sewer laterals even if your lateral lays within an OWASA easement.

However, in certain circumstances, we may repair structural failures and settling in the part of a sewer lateral in a public street right-of-way at no charge. For example, when we repair or replace public sewers, we will, where necessary, replace the portion of laterals within the street right-of-way.

Before we do structural repairs to the part of a sewer lateral in street right-of-way, it is necessary that the property owner or customer:

  • Make a request by letter, email or fax so that OWASA can determine whether we can repair the lateral under our policy. Please send the request to:

Manager, OWASA Distribution & Collections Systems
400 Jones Ferry Rd.
Carrboro, NC 27510
Email: info@owasa.org
Fax: 919-968-4464

  • Have in place or install a “clean-out” pipe for access to the lateral at the boundary of the right-of-way and private land.
  • The clean-out must have at least the same diameter as the 4” sewer lateral.
  • Have a plumber inspect the lateral with a special video camera to confirm whether a structural repair is needed and provide the video to us.
  • Give us written permission to work on the sewer lateral.
  • Agree to reimburse us for our costs for labor, equipment, time and materials if we start work and then determine that a structural repair is not needed.

OWASA inspects the part of new sewer laterals installed by developers or property owners in public street right-of-way and in sewer easements. Our policy is intended to help property owners in situations where factors outside of the control of the owner may affect the structural condition of a lateral within street right-of-way. At the same time, our policy is intended to encourage property owners to properly maintain and use their private plumbing systems to avoid blockages from debris, roots, grease and more.

If you believe there is a blockage in your sewer service lateral, please contact us at 919-537-4292 or info@owasa.org so that we can check whether the blockage is in our public sewer before you hire a company to clean the service lateral.

Water Heater

Your water heater performs a simple function: It warms water you use to wash your clothes, dishes and, well, yourself. But its functions might also impact your plumbing system.

Most water heaters should be flushed once per year to remove sediment that might collect at the bottom tank. Please follow manufacturers directions regarding water heater flushing.

Just like all matter, water expands slightly when it’s heated. This expansion may lead to an increase in pressure within the plumbing system. Increased pressure could exhaust your water heater’s emergency PRV, damage the flexible hoses used by appliances or cause leaks in pipes and other fixtures.

You can install a thermal-expansion tank near the water heater, or a toilet-tank “fill valve” with a PRV to relieve pressure from thermal expansion of water. Installing an expansion tank should be done by someone qualified to do so; installing a toilet fill valve is simpler, but it is important to seek advice and help from a licensed plumber if you do not know how to do this.

Clean-out Pipe

The wastewater line leaving your house should have a vertical clean-out pipe with a removable cap. Clean-out pipes make it easier to perform maintenance, such as removing blockages from the lateral.

The clean-out pipe is often installed near the boundary between private property and the public street right-of-way — the several feet of public space on each side of a roadway. The cap on the clean-out pipe prevents stormwater, trash and debris from getting into the lateral and then into the public sewers. The cap is especially important, because our sanitary sewers are not designed to carry stormwater. If stormwater gets into an OWASA sewer, stormwater may exceed the capacity of the pipe, and an overflow from a manhole may result. Further, debris and trash entering a sewer may block the flow of wastewater inside the pipe and cause an overflow.

Maintaining My Plumbing System

Aside from knowing all these elements of your plumbing system, pretty much anyone can follow these easy maintenance tips:

Check your water bill every month for unexpected high water use.

This could indicate there is a leak somewhere in your plumbing system. Toilet flappers are one of the most common culprits for leaks, and they can waste as much as 100,000 gallons every month; for context, residential water use averages about 4,000 gallons each month. To check a toilet with a tank for a leak, put food dye in the tank and wait 15 to 20 minutes without flushing; if the dye appears in the toilet bowl, there is a leak, probably at the flapper at the bottom of the tank. If you confirm that the flapper leaks and replace it, be sure to get a flapper suitable for use with water containing our secondary disinfectant, chloramines.

Make sure that you have an emergency shut-off valve and know its location within your building.

If a major leak occurs, being able to quickly turn off your water will save water, money and possible damage to your property.

Dispose of fat, oil and grease responsibly.

Fatty materials accumulate and harden to a plaster-like consistency within pipes, causing wastewater overflows, back-ups and more. Learn more about proper disposal of fat, oil and grease.

Protect your pipes from freezing weather by closing cracks and other openings in unheated areas with water pipes.

You can use insulation, plastic, newspaper and other materials to keep out cold air. Foundation vents may be hinged so they are easy to close. If you cannot protect pipes from freezing temperatures or for other reasons believe that pipes may freeze, you can let water drip from fixtures to reduce the potential for frozen pipes to burst. If frozen water bursts a pipe, the repair costs, property damage and water loss may exceed the cost of simple precautions with limited cost.

Periodically check your fixtures for leaks and drips.

Common leak sources include indoor faucets, outdoor spigots, showerheads, washing machine hoses and, if you have one, your irrigation system. A small drip or leak can waste thousands of gallons over time.

Monitor for leaks.

Register for the Agua Vista Web Portal and track your water use for leaks.

OWASA does not evaluate or endorse plumbing companies, but we recommend that you have plumbing work done by a licensed plumber or by someone you trust with expertise in plumbing. Improper plumbing work can cause significant water waste.

Who Owns Which Pipes?

We maintain…

  • the public water pipes (also referred to as “lines” or “mains”), usually 8” or more in diameter, installed in the street right-of-way
  • the pipe from the water main to our water meter
  • the water meter, box and cover
  • the meter “yoke” that holds the meter, including two short, curved sections of pipe on each side of the meter

If you see evidence of a leak in a pipe that OWASA owns and maintains, please call us at (919) 968-4421.

You maintain…

  • the service pipe connecting the meter assembly to your residence or other building
  • the nut or other fitting that connects your service pipe to OWASA’s meter assembly
  • your plumbing system, including pipes, the pressure-reducing valve, thermal-expansion tank or pressure-relief valve, water heater and other appliances and fixtures
  • the sewer lateral that connects your house to the sewer main

Backflow Prevention

Protecting our community’s water supply is a team effort. OWASA takes seriously the responsibility of delivering high-quality drinking water to customers. One way that you can help is by properly installing and maintaining a backflow prevention assembly where needed.

Backflow can occur when pressure decreases in one part of the public water distribution system. Backflow prevention devices in locations with irrigation systems, swimming pools, and at commercial locations help to protect the quality of the treated drinking water in an instance where pressure decreases due to a water line break, during firefighting operations, or similar circumstances.

The ultimate goal is to provide the highest quality drinking water possible to customers, so please make sure to have your backflow prevention device checked annually. OWASA has partnered with BSI Online to coordinate the annual testing program. Visit the BSI Online website for more information or contact BSI Online by calling (800) 414-4990 or via email at bsionline@backflow.com. 

Thank you for helping protect the drinking water for all of our community. 

Backflow Prevention Ordinance

effective January 1, 2017

Blackflow/Cross Connection Control Manual
Certified Backflow Testers
Frequently Asked Questions


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conservation tips!




Conservation of natural resources — including water — is a strong value in the Carrboro-Chapel Hill community, and sustainability is one of OWASA’s core values. Together, we have achieved remarkable water conservation: Drinking water use in our community has fallen and returned to levels not seen since the early ’90s, despite the community’s double-digit growth in the last two decades.

Conservation practices and investments make our community better prepared for droughts, defer the need for multi-million dollar projects to expand our system capacity and reduce greenhouse gas emissions from the use of conventional energy sources to pump water. Also, reducing hot-water use in homes and businesses lessens energy use and greenhouse gas emissions from heating water with conventional fuels.

Our conservation policy is to develop, fund and implement a cost-effective water conservation and demand management program meeting the Carrboro-Chapel Hill community’s long-term water supply needs. We accomplish our goals by making the highest and best use of our local water resources and eliminating the need for costly new water supply sources and facilities.

So, aside from our year-round conservation standards, what are the best ways to conserve water? There are many variables going into the answer to this question, including everything from your water-use patterns to the age and efficiency of your water-using appliances. You can improve your water conservation by following any of a few easy, simple steps.

Conservation Tips

The following tips are a good start for you to increase your own water conservation.


Take showers instead of baths.

Showering normally requires much less water than running a full bath.

Take shorter showers.

Limiting your shower time to five minutes or less greatly reduces water use.

Replace old showerheads.

Leaky old showerheads waste tons of water. High-efficiency heads use as little as 1.5 gallons per minute, whereas old showerheads use as much as five gallons per minute, so consider how much you’ll save on your bills. We provide free low-flow showerheads to customers upon request. Once you receive your new showerhead, you can watch this short video to learn how to install it.

Turn off the water while you lather and scrub during showers.

It also can’t hurt to shut off water when washing your hands or face.

Flush your toilet only when necessary.

Older toilets especially use much more water — upwards of five gallons per flush — than newer, high-efficiency models.

If you can’t replace an old toilet, put a bottle of water in the tank to reduce the amount of water used in flushing. Be careful to avoid affecting the normal operation of the flapper and fill valve.

Only run fully-loaded clothes- and dishwashers.

Try to cut down on how often you wash your clothes and dishes, as these appliances use a lot of water. If you have the means, consider installing an Energy Star-rated washer to save water, energy and money.

Periodically check for leaks in water-using appliances.

Many household appliances use water, so that leaves plenty of room for mechanical error. For example, toilet flappers are common causes of water waste and high bills, as they tend to leak or even just get stuck in an open position.

Register for Agua Vista so that you can be notified of leaks via email, text or voicemail.

If you fix a leak, make sure to contact us.

We may be able to reimburse you for this accidental water usage. Call OWASA Customer Service at (919) 537-4343, or email us at customerinquiries@owasa.org.

Replace your inefficient appliances.

This is a big ask, but if you have the means, replacing old toilets, clothes- and dishwashers, showerheads, faucets and other appliances with high-efficiency units helps significantly to conserve water. Also, considering how much you’ll reduce your water use, new fixtures eventually pay for themselves by reducing your monthly OWASA bills.

For more resources on high-efficiency water-using appliances, here’s a list of appliances approved by the Environmental Protection Agency to improve water conservation:


Follow our year-round conservation standards for watering and irrigation.

The water you use to water your plants, irrigate your fields, clean your siding, wash your car and more is drinking water. Be mindful of your water use, and follow the rules on our conservation chart. One memorable, hard-and-fast rule: Odd addresses can water on Tuesday, Thursday and Saturday, and even addresses on Wednesday, Friday and Sunday.

Water your plants and lawn less — and less often.

Overwatering can damage or weaken grass and other plants. Check our conservation chart to see when to water.

When landscaping, plant native, sustainable flora.

Consider planting drought-resistant, non-invasive trees, shrubs and groundcover, or a drought-tolerant, warm-season grass such as Bermuda. Drought-tolerant landscaping can add regional beauty and character, improve wildlife habitat and reduce fertilizer & pesticide use. All these benefits save you water and dollars.

Check for an outdoor leak in your service pipe.

A wet spot on the ground during dry weather is as suspect as it seems. Leaks may occur in the private water service pipe that carries water from OWASA’s meter to a residence or other building. If there is a leak in this service pipe, you may need help from a plumber to find and fix it.

Register for Agua Vista so that you can be notified of leaks via email, text or voicemail.

Weatherize your irrigation system.

Freezing conditions can damage your irrigation system and cause leaks. Check your system manufacturer’s website for more info on weatherizing.

In Case of Drought

Along with our standard conservation schedules, we have adopted a Water Shortage Response Plan in accord with State requirements.

We also adopted a Drought Response Operating Protocol (DROP), describing our procedures and criteria for making water-supply and demand-management decisions in an extended drought. Read the OWASA Board of Directors’ resolution.

Standard Conservation Schedules
Water Shortage Response Plan
Drought Response Operating Protocol (DROP)
OWASA Board of Directors’ Resolution

Protect the Water

What you pour down the drain in your home (or the storm drain down the street), what you flush down the toilet, how you fertilize your lawn — these all impact water quality. Wastewater treatment processes, regulated by the State and Federal governments, remove much of these contaminants. Still, traces of chemicals that get sprayed on the ground or pharmaceuticals flushed down the drain can end up in local waterways. There are so many ways that, together, we can protect the community’s water.

What OWASA Does…

  • Supports and conducts scientific research
  • Supports stringent zoning and land-use controls in the watersheds near our water sources
  • Prohibits body contact with lake water
  • Minimizes use of gasoline engines on our lakes
  • Limits extension of public water and sewer service in our local watersheds
  • Purchases and manages property, plus conservation easements, in watershed areas critical for protecting high water quality

What You Can Do…

  • Sweep debris that collects in your walkway or driveway instead of washing it
  • Dispose of chemicals and pharmaceuticals responsibly, not down a drain or toilet
  • Properly fertilize your landscape — if you use too much, it can run off into a local waterway
  • Volunteer to monitor stream water quality, or participate in stream clean-up work
  • Direct water from downspouts to vegetated areas or a rain barrel
OWASA Energy Management

We recognize that the use of energy at our facilities impacts land, water and air resources, and our use of fossil fuels contributes to increased greenhouse gas emissions. Our use of energy also directly impacts you, our customers — operating with fossil fuels costs us about $1.1 million a year.

To reduce costs and the environmental impacts of our operations, and to improve OWASA’s sustainable practices, we have launched an organization-wide Energy Management Program to meet the energy goals and objectives set by the OWASA Board of Directors:

  1. Reduce use of purchased electricity by 35% by the end of Calendar Year 2022 compared to the Calendar Year 2010 baseline
  2. Reduce use of purchased natural gas by 5% by the end of Calendar Year 2020 compared to the Calendar Year 2010 baseline
  3. Beneficially use all Mason Farm Wastewater Treatment Plant biogas
  4. Formally engage local governments and partners in discussion about potential development of biogas-to-energy projects at the Mason Farm plant

Forest Management

You may be surprised by this, but OWASA owns woodlands surrounding local reservoirs to protect the community’s water. Where and why, you ask? Read on to learn.

OWASA owns 2,400 acres of forested lands, the majority of which is in the Cane Creek watershed. Cane Creek Reservoir is a main water source for the Carrboro-Chapel Hill community. Protecting the Cane Creek watershed and its surrounding woodland helps safeguard water quality for the community. Sustainable forest management facilitates this protection and provides other environmental benefits, such as reducing the risk of wildfire.

Our incremental approach to forest management includes managing a few tracts of land at a time. Using this approach, we develop management plans for a few high-priority tracts, review those plans with neighbors, incorporate feedback and then implement the resulting plans. We apply any lessons learned to our next group of priority tracts.

A key part of our approach is engaging with residents and the community near our forested land. We wish to enable two-way dialogue — to garner local insights and knowledge, exchange ideas and minimize impacts on neighboring residents — to protect the watershed together.