The Pittsboro Water Filtration Facility is located on U.S. 15-501 less than a mile from the Haw River.

The facility is certified to clean and purify 2 million gallons of drinking water per day, which is nearly double the daily water use of Pittsboro. In addition, storage at the facility and around town allows for the storage of nearly 3 million gallons of clean water at any given time.

Facility staff have been awarded the Area Wide Optimization (AWOP) Award numerous times over the past decade. The AWOP Awards are given annually to water systems demonstrating outstanding turbidity removal, a key drinking water quality test.

The Water Process

The professional, knowledgeable staff at the Pittsboro Water Filtration Facility works around the clock to collect, treat, purify, and distribute the highest quality drinking water. This complex process laid out in the above diagram and detailed step-by-step below ensures that every drop of water reaching your tap is as free from contaminants and pathogens as possible.

1 - Collection

Raw water is drawn from the Haw River near the Bynum Bridge and pumped to the facility through large underground pipes. The water is stored in a large tank where the treatment process begins.

2 - Coagulation & Flocculation

Special chemicals, called coagulants, are added to the water. These chemicals help dirt and particles in the water stick together, forming clumps known as "floc." The water is then stirred in a series of mixers, which helps the floc get bigger.

3 - Sedimentation

After coagulation and flocculation, the water is allowed to settle. Floc sinks to the bottom, leaving clearer water on top. This process ensures that most contaminants are removed.

4 - Filtration

The clearest water from the top of the sedimentation tank is directed through a series of filters made of sand, gravel, and charcoal. These filters trap any remaining particles, bacteria, and pathogens.

5 - Disinfection

Disinfectants are added to the filtered water to kill any remaining harmful microorganisms. Additional chemicals are added to protect the inside of the distribution pipes. 

The disinfected water is sent to a clearwell to allow the recently added chemicals to fully activate. 

6 - Granular Activated Carbon (GAC) Filtration

While being stored in the clearwell, water is constantly pushed through a GAC filter. 

Our GAC filters are two tall cylindrical tanks filled with activated carbon pellets. The pellets help remove emerging contaminants, such as per- and polyfluoroalkyl substances (PFAS), with a removal rate of up to 99.9%.

7 - Storage

Water treated by GAC filtration is returned to the clearwell for further storage. 

The clearwell supplies the distribution network and provides a buffer against increased demand or reduced supply.

8 - Distribution

From the clearwell, water is pumped into the distribution system -- a network of pipes and tanks that deliver water to homes, businesses, and other establishments in Pittsboro.

GAC Advanced Filtration System

Pittsboro invested nearly $3.5 million to install GAC filters at the water filtration plant to protect customers from emerging contaminants in the water. Emerging contaminants are chemicals that get into water sources that can have detrimental affects on wildlife.

Understanding GAC: GAC is derived from organic materials like coconut shells or coal. These materials undergo a carbonization process, followed by activation using super-heated steam. The result is a highly porous material with a large surface area, ideal for adsorbing various contaminants.

Why GAC?: Traditional water treatment processes, while effective at removing traditional contaminants, may not remove certain organic compounds, chemicals (such as PFAS), or micro-pollutants. GAC's unique adsorptive properties make it very efficient at capturing these contaminants. Moreover, GAC effectively removes unpleasant tastes and odors, ensuring water is safe and has a pleasant taste and smell.

The GAC Process: Water is passed through granular activated carbon beds. As water flows through, contaminants are adsorbed onto the carbon particles. Adsorption means that the contaminants stick to the outside of the filtration media. Over time, as the outside of the carbon pellets become saturated with contaminants, they are removed and then regenerated off-site. This recharge is done in an environmentally sustainable way, with the process not releasing any of the collected PFAS into the environment. The Town maintains two separate GAC filters at our water plant but only uses one at a time. This means that as soon as our water treatment plant staff find evidence that the GAC is starting to experience a “breakthrough,” or the presence of PFAS in the lower level of the filter, we can switch to the other filter and continue to have 100% GAC treatment while the media in the used tank is replaced and regenerated.

Benefits of GAC: Beyond its superior contaminant removal capabilities, GAC offers multiple benefits. It acts as an added layer of purification, ensuring water quality consistency. GAC systems are also sustainable, with a lower environmental footprint than other advanced treatment methods. Furthermore, GAC-treated water often has a fresher taste, enhancing the drinking experience.

GAC in Pittsboro: To provide the highest quality drinking water for customers and residents, the Town of Pittsboro dedicated significant time and money to implementing a GAC filtration system. The Town conducted numerous engineering and operational studies and ensured staff received training to integrate GAC into the water treatment process seamlessly. The GAC facility operates round the clock, treating every drop of water the Town produces daily. The result is a significant enhancement in water quality, setting new standards in municipal water treatment.

How Much Did the GAC Cost: At nearly $3.5 million, this significant investment is one of the largest single infrastructure projects undertaken within the Pittsboro utility program, with funding coming from the town’s revenue and grant funding.

Testing Process

Water quality is tested at every stage of the treatment process. 

A state-certified laboratory is located on site at the Pittsboro Water Filtration Facility. Certified technicians work around the clock -- performing hundreds of tests every single day -- to make sure each step of the process is working optimally and every drop of finished water that leaves the facility meets the highest regulatory standards.

In addition, laboratory staff test tap water at 5 different sites across the distribution system every month. These tests help our experts monitor water quality at your tap, not just inside the filtration facility, ensuring that the water is flowing through the distribution system as expected.

If you notice any changes to your water or have any concerns about your water quality, you can call the filtration facility at (919) 542-3530.