Tag Archives: drinking water

Construction, Repairs and Spills, Water Quality

Unidirectional Hydrant Flushing

Charlotte Water clears mineral deposits (sediment) from water pipes by flushing water through fire hydrants. The mineral deposits in the pipes are only dislodged when the water is flowing at very high speeds. It has not affected water quality but may have reduced water pressures and pipe capacity.

Water quality sampling stations (green boxes) are installed in the neighborhood so staff can test the water before and after flushing hydrants.

Customers receive a postcard and a notice on their door before this type of hydrant use. Updates will be posted on NextDoor.

Discolored Water is Possible

Customers near flushing may notice temporarily discolored water and lower than normal water pressure. The discoloration does not pose a health risk. However, avoid using tap water or running the washing machine or dishwasher until flushing is complete.

If you experience some discoloration in your water from nearby flushing, run the cold water at one tap for 5 minutes to see if it clears. If it does not clear wait an hour and try again. When the water runs clear, flush any taps where discolored water was present. If not clear after one hour, call 311 to report issues

If you have a question about this project, please contact us at 311 or 704-336-7600.

Fire Hydrant Unidirectional Flushing Frequently Asked Questions

What is unidirectional flushing?

Unidirectional flushing is used to improve and maintain our high-quality drinking water. Sediments and mineral deposits in the pipes can discolor drinking water. The high-speed water flows used in unidirectional flushing is an efficient and cost-effective way to remove sediments and deposits from the pipes and prevent potential water quality issues.
Why does Charlotte Water flush drinking water pipes?

Drinking water pipes need to be flushed out to improve water quality. Over time, very fine sediment from mineral deposits and organic matter settle out of the water and accumulate in the bottom of the pipes. While the sediments are generally harmless, they can make the disinfectant in the water less effective. Additionally, sudden changes in the flow of water can disturb these sediments resulting in cloudy, discolored water.

What should customers expect to see?

While crews have the hydrants open, passersby may notice a lot of water running down the road to a nearby storm drain. At times, the water may be very cloudy or brownish.

Is it common to flush the pipes?

Charlotte Water uses three techniques to clean and maintain the drinking water system: spot flushing, auto flushing, and unidirectional flushing.

Spot flushing is used to address discolored water issues. This includes when drinking water is discolored due to a disturbance in the system such as construction or other hydrant activity. Crews open fire hydrants to flush this water out of the system and bring fresh water into the pipes.
Auto-flushing is similar to spot flushing and is used to maintain water quality by reducing the water age in the distribution system. This type of flushing uses an automatic flushing device, called an auto-flusher, which is connected to hydrants and programmed to flush water at certain time intervals and flow rates. Using an auto-flusher reduces the amount of staff time needed to maintain consistently better water quality at a certain location in the distribution system while using water in a more efficient manner.

Unidirectional flushing is not used in response to a specific water quality issue but instead is used as routine maintenance to prevent problems from arising. The goal of unidirectional flushing is to clean the insides of the water delivery pipes. Cleaning the pipes removes sediment that builds up in the pipes. This reduces the potential for water quality problems. Unidirectional flushing works by forcing water in the pipes to flow at much higher speeds than normal. Flushing crews first open and close valves to isolate sections of pipe, and then the water and any mineral sediments in the pipes are flushed out through an open fire hydrant.

Has the sediment built up in the pipes harmed me?

The sediment from mineral deposits in the pipes is only dislodged when the water is flowing at very high speeds. It has not impacted water quality but may have impacted water pressures and pipe capacity.
Unidirectional flushing will have minimal impacts to customers. If you see hydrant flushing crews working in the area, please drive carefully and treat them like any other road construction crew.
Customers in the immediate vicinity of flushing may notice temporarily discolored water and lower than normal water pressure. The discoloration does not pose a health risk. However, avoid using tap water or running the washing machine or dishwasher until flushing is complete.
If you experience some discoloration in your water from nearby flushing, run the cold water at one tap for 5 minutes to see if it clears. If it does not clear wait an hour and try again. When the water runs clear, flush any taps where discolored water was present. If not clear after one hour, call 311 to report issues.

Behind the Scenes, History

The History of Charlotte Water

In 1899, Charlotte City Council purchased Charlotte Water Works Company to provide drinking water and fire protection for the City of Charlotte. 

In 1972, the City and County consolidated efforts to provide a single water & wastewater service. This department began with 72,000 customers and 2,300 miles of pipe to maintain. It provided 48 million gallons of drinking water and treated 40 million gallons of wastewater. 

During the 1980s Charlotte Water began serving all of Mecklenburg County. Over the decades, infrastructure has grown to keep pace with the community. The technology was used to switch from septic storage to state-of-the-art wastewater treatment and using chemicals like chlorine, fluoride, and ultra-violet rays to improve water quality.

History Timeline

1870 – City Council identified a need for a water supply system. 

1876 – Charlotte constructs sewer service under Trade Street.

1881 – First water supply company established called ‘Charlotte Water Company’.

1899 – 50,000-gallon standpipe (a pressure regulator) in Dilworth was built for fire protection. The City of Charlotte purchased the water and wastewater system. 

1900 – 5 million gallons a day filter plant and pumping station on Irwin Creek (less than a mile east from present Vest Water Treatment location on Beatties Ford Road).

1903 – The Original Catawba River Pump Station was opened to provide fire protection and drinking water. The pump station was impounded and flooded by Duke Power in 1920 to create Mt. Island Lake.

1903 – The first wastewater septic/treatment plants were built on property now known as Revolution Park & Freedom Park. 

1905 – First water treatment plant built.

1911 – Irwin Creek water supply failed due to a severe water shortage. Trains temporarily brought in water. Utility Department built a new water intake facility on the Catawba River. According to “Water Rates and By-laws of Charlotte Water Works,” the deposit to receive water was $1.50. The monthly rate was $.55 for 1,500 gallons or less. In 1911 customers were located in the ‘four wards,’ Dilworth, Brevard Street, and East Sixteenth.

1917 – 60 million gallon reservoir built (steam and electricity used for operation) to store water.

1920 – The population of Charlotte was 46,538.

1922 – Mt. Island Lake created by Duke Power and a new raw water intake facility built on the lake. Vest Water Treatment Plant built (On Beatties Ford Rd).

1923 – Charlotte abandoned septic tanks within the city limits.

1927 – Charlotte begins construction of two new plants on the current Sugar Creek and Irwin Creek locations. Sugar Creek (located at Park and Tyvola Road) and Irwin Creek (located on Billy Graham Parkway) wastewater treatment plants were actually miles outside of the city limits when first operated.

These plants had the capacity to treat 6 million gallons a day with a flow of 3 million gallons a day in the late 1920s.  The facilities were implemented to protect the environment and water providers downstream.

1929 – The Literary Digest proclaims “Engines Run on Sewage Gas…the first American city to obtain power upon a plant-operating scale from sewage sludge gas falls to Charlotte…the savings in power cost should pay for an engine installation within three years.”

1948 – An Industrial Waste Ordinance was adopted to provide treatment of industrial wastes that would otherwise be discharged into creeks.

1949 – Charlotte’s first use of fluoride as a dental health experiment project.  The natural level of fluoride in the water was .05 – .10 parts per million (ppm).  The experiment prescribed the dosage of 1.05 ppm.  This level was maintained for a month.

1950 –Charlotte population 134,042 served by 36,000 water meters.

1959 – Franklin Water Treatment Plant (5200 Brookshire Blvd) built.  It provided 12 million gallons of drinking water a day.  It now provides over 100 million gallons of drinking water a day.

1960 – Charlotte population is 201,564.

1963 – Cowan’s Ford Dam and Lake Norman created by Duke Power.

1966 – McAlpine Creek Wastewater Treatment Plant built and serving the southern part of Mecklenburg County.

1970 – Water use was 33.8 million gallons a day, served via 1,091 miles of water pipe, 82,478 meters, and 3,234 hydrants.

1972 – Charlotte-Mecklenburg Utility Department (CMUD) formed as a division of the City of Charlotte from existing City and County departments.

1979 – McDowell and Mallard Creek Wastewater Treatment plants built to serve the Huntersville area and University area respectively.

1984 – Agreement with six surrounding towns in Mecklenburg County to provide water and wastewater services.

1990 – 100,000th customer and 4,000 miles of pipe.

1996 – Operation of Irwin Creek Plant (along with Vest Water Plant) put up for competitive bid.  The city developed a winning bid, beating 7 international private companies by more than 20%.

1998 – North Mecklenburg Water Treatment Plant completed. Later named Lee Dukes Water Treatment Plant.

2003 – Automated meters in use in North Mecklenburg.  Radio signals send the customer’s water usage to a computer.

2015 – Name changed to Charlotte Water (CLTWater).

Events, What's Going On?

Charlotte Water Celebrates Drinking Water Week 2023: Saturday, May 6th at Quest Nature Center

Charlotte Water is thrilled to continue the tradition of celebrating National Drinking Water Week within our communities. Drinking Water Week recognizes the vital role water plays in everyday life for both water professionals and the communities they serve.

Water Week 2023 Flyer

This year, Charlotte Water is excited to host a day of family fun at the Quest Nature Center on May 6th, 2023, from 11 am to 3 pm. There will be games, guest exhibitors, and many family-friendly activities!

RSVP to let us know you’re coming at our eventbrite: https://www.eventbrite.com/e/water-week-celebration-2023-tickets-619160835727?aff=ebdssbdestsearch

Charlotte Water invites the public to learn about the importance of clean, safe water in daily life and its role in our public health, environment, and thriving community.

Come meet some of Charlotte’s water heroes and sustainability groups that support our region!

Charlotte Water is proud to serve our community 24/7, 365 days a year, bringing clean, safe drinking water to over 1.1 million residents across Mecklenburg County.

My Water, Water Quality

Why is My Water Bubbly, Cloudy, or Discolored? What is Turbidity?

A little bubbly water may catch you by surprise, but don’t worry. We didn’t change your tap to champagne. Sometimes air can get trapped inside pipes and cause temporary bubbles in a glass of water. If you notice cloudy or discolored water, it may be mineral deposits.

Very fine sediment from mineral deposits settles out of the water and accumulates in the bottom of the pipes over several years. The mineral deposits in the pipes can be dislodged during sudden changes in the direction or flow of the water (i.e., water main break, hydrant use, etc.).

CLTWater notifies water billing customers of planned and unplanned water outages as soon as possible. If you rent, you can sign up to receive alerts at charlottewater.org. If you are notified of a water outage, please turn off dishwashers, washing machines, and automatic ice machines until water service is restored.

Once water service is restored, you shouldn’t experience bubbly, cloudy, or discolored water. If you do, please:

  • Run cold water for 10 minutes (preferably an outside spigot or bathtub first).
  • When water runs clear, run cold water through any faucets where discolored water is present.
  • If the water isn’t clear, run cold water for an additional 10 minutes and carefully unscrew faucet aerators to remove and clean.
  • If water is not clear, please call 311 or 704-336-7600 and say or select water emergency.

Turbidity is the measure of the cloudiness of the water and is a key water quality measurement taken at our treatment plants, fire hydrants, and sampling stations. Charlotte Water (CLTWater) tests water throughout Mecklenburg County daily.

Your home’s humidity will typically be less than one Nephelometric turbidity unit (NTU). A glass of water with a reading of five NTU is just noticeable to the average person. If you notice cloudy water, it is likely a higher NTU, and you should follow the steps above.