Virtual Tour of the Cary Apex Water Treatment Facility

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A Virtual Tour of the Cary/Apex Water Treatment Facility

Thank you for joining us for a virtual tour of the Cary Apex Water Treatment Facility. This facility provides drinking water to over 280,000 citizens in central NC. Most of the time we don't think about our drinking water. We just turn on the tap and it is there, ready to drink, use for bathing, watering plants or cleaning. Today we will be discussing how water gets from nature's sources to our faucets.

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We are going to talk about water in nature , where our drinking water comes from, how safe drinking water is produced, how water is distributed to our community, how testing is performed to verify its safety, and finally how the process water and dirt are returned to the environment.

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Let's start by learning about water in nature

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Most of us are aware of the hydrologic cycle where the limited water on earth continuously cycles through the different stages such as: precipitation, evaporation, and condensation.

Condensation

Precipitation

Evaporation

But have you ever thought about the community water cycle? Water starts with a drinking water source like a river or lake. It is pumped to the water treatment facility where it is purified, then distributed to people’s homes where it is used and discarded down the drain. The wastewater is treated at a water reclamation facility. Then the treated wastewater goes back into the environment where a portion of it may become the source water for a downstream community.

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Community Water Cycle

Lake

Water Treatment

Water Reclamation

Homes

Discharge

Depending on where you live, your drinking water comes from different places. If you live in a rural area, your water may come from underground aquifers in the form of well water. Here at the Town of Cary, our drinking water begins its journey as surface water or more specifically Jordan Lake.

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What is an underground aquifer?

What is surface water?

Jordan Lake is operated by the US Army Corps of Engineers. In 1983, the Haw River was impounded (meaning it was dammed to create a man-made lake). The Corps built the lake to help prevent flooding downstream; to provide a water source for our area; and to offer recreation such as swimming, fishing and boating.

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Jordan Lake Dam

As a Cary water customer, your water starts its treatment journey at the Raw Water Intake located off of the Highway 64 causeway. Lake water, also known as Raw water, flows by gravity through a large pipe that is screened to prevent fish, sticks and debris from entering it.

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What does the intake pipe look like?

Drone Footage

The water coming in from the intake pipe flows to the Raw Water Pump Station. This building houses pumps, electrical equipment, computer control systems, and emergency power generators. So even when storms cause power outages water will always be pumped to the treatment facility.

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What does the structure look like underground?

Raw Water Pump Station

Even before Jordan Lake water gets to the treatment facility, the process of turning it into drinkable water has started. While the raw water flows through the Pump Station, Powdered Activated Carbon is added. Some organic and inorganic material adhere to the activated carbon which is later physically removed at the treatment facility.

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Powdered Activated Carbon

What are the different sources of carbon?

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The lake water is pumped 6 miles in underground pipes to the Cary/Apex Water Treatment Facility.

What do the pipes look like?

Intake

6 miles

Welcome to the Cary/Apex Water Treatment Facility where the real fun begins. This facility provides the drinking water to your homes, restaurants, parks, schools, swimming pools, the airport and everywhere else in Cary, Apex, Morrisville, and parts of RTP.

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Where is the service area?

It began operation in 1993 with the ability to produce 12-million gallons of drinking water a day. The plant was expanded several times as the area's population grew. The most recent expansion occurred in 2019 and enables us to produce up to 56-MGD. Currently we regularly treat approximately 23 MGD. In order to do that, the facility employs 28 staff members including Operators, Maintenance, Laboratory and Administration.

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How much water is a million gallons?

Drone Footage

There are 5 steps that complete the water treatment process. The first three remove dirt particles and the last two remove germs. The five steps are Ozonation to oxidize organics and remove taste and odor problems; flocculation and coagulation to make dirt particles stick together; sedimentation to capture the large dirt particles; filtration to remove smaller dirt particles; and disinfection to kill germs. We will discuss these steps in the next few slides.

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Disinfection

Ozonation

Filtration

Sedimentation

Flocculation & Coagulation

After arriving at the water treatment facility, the raw water is surrounded by bubbles of ozone that oxidize organics, remove color so water becomes clearer and to reduce taste and odors so the water is pleasant tasting and doesn't taste like fish and dirt. The ozone is generated onsite by splitting and recombining oxygen atoms to form ozone.

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Step 1: Ozonation

How Does it Work?

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Watch this video to get an overview of the next three steps: coagulation and floccculation, sedimentation and filtration

Watch Video

Coagulation happens within this structure, called the Rapid Mix. Operators add Aluminum Sulfate and polymer to make the dirt particles stick together to form heavy particles called floc. The water is mixed really fast which is why we call it the rapid mix.

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Step 2: Flocculation and Coagulation

What's Happening in the Rapid Mix?

Watch Mixing

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Once the floc forms, it is gathered in the sedimentation process. In the tabletop demonstration, the particles fell to the bottom due to gravity. At Cary's treatment facility, we use Super Pulsators because it allows us to treat more water in a limited area. The water is pulsed up from the bottom. The floc collects on the settling plates or baffles and the clean water goes out through the collection laterals or pipes with holes in the top where it goes on to the next step in the process.

How does it work?

Step 3: SedimentationSuper Pulsator®

or baffles

Watch Video

Any dirt particles that are remaining are removed through filtration. Before it goes through the filters, we jumpstart the disinfection process by adding chlorine in the form of liquid bleach. Then the chlorinated water flows down through layers of sand and anthracite coal in the filters, where those small lingering particles are removed. Since the particles are trapped in the filters, periodically those filters have to be cleaned. We do that by forcing water backwards through the filter.

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Step 4: Filtration

Watch Backwash

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At this point, Operators add fluoride to the drinking water to help keep your teeth healthy.

at least 25%

How Does it Work?

Before the final disinfection step, Operators also add phosphates to the drinking water. Phosphates form a protective coating on the inside of pipes that deliver water to you. This coating helps prevent metals such as lead and copper that may be present in plumbing installed prior to 1987 from getting into the water.

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Without Phosphate Protective Coating

With Phosphate Protective Coating

In the disinfection step, we add another dose of chlorine to kill germs in the drinking water. Chlorination has been credited with practically eliminating waterborne diseases such as cholera and typhoid fever.

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Step 5: Disinfection

The water then travels through baffles inside the clearwell storage tank to ensure there is appropriate contact time with chlorine. The baffles keep the water organized - similar to if you are at an amusement park and you have to wait in a long line that corrals back and forth before getting on the roller coaster. Then ammonia is added to form chloramines before it enters the final two clearwells.

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Clearwells Onsite Storage Tanks

How do the baffles work?

Ozonation

Flocculation & Coagulation

Sedimentation

Filtration

Disinfection

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That is the end of the 5 step process that we use to produce high quality drinking water. The water is now ready for everyone to use.

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In order to get it to our community, it takes up to 10 pumps to push it through the underground pipes to you.

FinishedWater Pumps

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Now let's talk about what happens to the water after it leaves the water treatment facility.

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The water travels in pipes to one of 8 elevated water storage tanks or 1 ground storage around town. Have you ever wondered why the tanks are up so high? That way gravity can help maintain the water pressure at your home and allow us to meet variations in water use.

Water Storage Tanks

Give 2 reasons it is good to store more water than typically needed?

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Water Pressure at your home is related to your home's elevation and the elevation of the elevated water storage tank.

Your Water Pressure

Watch Video to learn More

Can you believe that Cary has over 1,100 miles of water pipe? It is hard to believe, but if the pipe was stretched out end to end it would reach from Cary to the Canada. That is a lot of pipe to maintain. Thankfully, we have a whole crew dedicated to doing just that. Whether it is the middle of the day or the middle of the night, we have crews to fix broken or leaking pipes.

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1,100+ Miles of Water Pipe

Would reach from Cary to Canada if stretched end to end

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That same water flows to over 11,000 fire hydrants in the town of Cary to help protect you, your homes and businesses.

Fire Hydrants

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Have you ever seen blue spray paint in your yard or in your street? That is a clue that drinking water pipes are underground to bring water to your home.

Blue Lines Spray Paint

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So that we know how much water is used, each property has a water meter. You might recognize this from your yard. Your water bill is based upon the quantity of water your household uses and the meter tells us this.

Water Meters

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Another thing you might see in your street, is a valve cover with the word Water on it. These are access ways for staff to turn off water to isolate and fix a leak in the distribution system.

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Valves

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You can drink and use the water confidently because it has been tested and monitored by specially trained staff. Let's learn about that testing process.

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This staff member is testing the water at one point in the over 1100 miles of pipe in our distribution system. Over 150 samples are collected every month from throughout our service area verifying the quality.

Regulatory Distribution Testing

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Before that water gets into the pipes, Water Plant Operators monitor computer trends, perform rounds where they physically look at chemical feed and other processes as well as test the water at the different stages in the treatment process every hour, 24 hours a day, 365 days a year.

How many tests do Operators perform each year?

Water Plant Operators

See Analysis in Action

Our State Certified Laboratory performs approximately 100,000 tests per year verifying the drinking water meets standards set by the US Environmental Protection Agency and the NC Department of Environmental Quality. Specialized laboratory equipment is used to test for over 150 different contaminants such as microbiological organisms, pesticides, and harmful chemicals. Contaminants are monitored down to the part per million, part per billion or even part per trillion levels.

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How much is 1 part per trillion?

The State Certified Laboratory

See Analysis in Action

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CaryNC.gov/waterreport

Test results are posted online each year in two reports. The Annual Water Quality Report contains results for any detected substances and the Water Quality Testing Summary details all the test results.

Test Results are Published Annually

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Returning the Process Water and Dirt Safely to the Environment

At the same time the drinking water is delivered to you, we also have to manage the process water and dirt that have been removed as we make the water drinkable.

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The solids that are removed from the super pulsators and the filter backwash water have to be treated before being returned to the environment. There is a small physical wastewater treatment facility onsite that does just that.

Solids Handling Process

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The clarified and dechlorinated process water is safely returned to the environment by discharging it to the nearby creek. While the solids are shipped in trucks to a local company where it is integrated into nutrient rich compost.

Returning to the Environment

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Thank you for your attention.

Thank you for your attention. We hope you now better understand the five step process we use to make Jordan Lake water drinkable and how we distribute it to our community to drink and use wisely.

How do you contact us for more information?