Behind the Scenes, Construction, How Things Work, Repairs and Spills
May 10, 2024 Cam Coley CLTWater Communications
Everyone has a job to do…
To watch coworkers underground to ensure they are safe. If someone is injured they are to call 911.
To communicate with equipment operators about raising or lowering materials in or out of the trench.
To supervise or verify that the project or repair is being completed efficiently and effectively.
Training opportunities for new coworkers to see how we safely work in a trench.
To hand equipment and tools down to team members in the trench.
And sometimes they are waiting on more equipment or materials to be delivered.
Trenches are typically just enough space for the minimum number people to get the job done. The less digging, the less time to restore the trench.
Construction, Repairs and Spills
August 25, 2023 Cam Coley CLTWater Communications
First, what is a wastewater overflow? A wastewater overflow, also referred to as an SSO (Sanitary Sewer Overflow), is a release of untreated or partially treated sewage from a municipal sanitary sewer, typically out of a manhole or a broken pipe.
While wastewater overflows are nearly inevitable in a system as large as Charlotte’s, we do our best to keep these incidents to a minimum to protect human and environmental health.
How can I tell if there is a wastewater overflow in a creek?
You may notice a gray, milky color or odor. If you do suspect an overflow, call 311 right away and say or select wastewater emergency, and a crew will respond.
What should I do if I see a wastewater spill?
Call 311 or 704-336-7600 and say or select sewer emergency. We will respond 24 hours a day.
How can I help reduce overflows?
- Toss in the trash: paper towels, wipes, hair, cotton swabs, feminine products, dental floss, coffee grounds, and excess food.
- Toss in the toilet: only toilet paper.
- Drain in the sink: soap suds, small amounts of food from the plate, and liquids.
- Take to a full-service recycling center: used and expired oils and grease.
What causes wastewater overflows?
- Clogs from wipes, paper towels, leftover kitchen grease, oils, or anything other than toilet paper.
- Pipe failure (tree falls and breaks pipe, stream/creek erosion causing the pipe to fall into the creek)
- Tree roots attacking and clogging the pipe
- Damage by nearby construction. (Reminder to always call 811 before you dig.)
How does CLTWater respond?
A rapid response crew will investigate the area and attempt to remove the clog. This work does not impact drinking water quality. Crews may run hydrants to flush the area, lightly apply lime to sanitize, and/or return to investigate other pipes. Residents and their pets are encouraged to avoid contact with the creek during an overflow response.
How does CLTWater respond to a large overflow?
There is a myriad of responses depending on the situation. For example – a tree falls into the creek, washing out the creek bank and undermining the wastewater pipe just behind the creek bank. Crews frequently inspect these areas, but erosion can occur quickly during heavy rain events. Crews will:
- Create a temporary access road or path if necessary to respond.
- Install a temporary wastewater pipe to bypass the broken pipe and stop the overflow. The pumps and temporary above-ground pipes are checked several times daily to prevent possible wastewater overflows.
- Stabilize the creek bank.
- Construct a barrier / temporary stream bank to protect workers.
- Remove the broken pipe.
- Install the new pipe and test it.
- Rebuild the stream bank with clean fill material (soil).
- Remove temporary pipes and pumps.
- Remove large spoil piles of dirt.
- Complete grading/drainage.
- Plant trees/shrubs and seed/straw the area.
- Restore the stream bank and revegetate.
- If the greenway was closed during work, it would be restored and reopened. When greenways are affected, CLTWater works with Mecklenburg County on restoration.
How does CLTWater handle tropical storms or heavy rains and prevent spills?
The underground sanitary sewer pipe network is not designed to handle rain, yet the runoff and flooding from large rains inevitably infiltrate the wastewater pipe network. Overflow basins at the five largest wastewater treatment plants capture and later treat more than 160 million gallons of rainwater mixed with wastewater. These equalization basins (EQ basins) prevent wastewater from overflowing out of manholes in our community.
CLTWater has also added several large wastewater pipes to help reduce the impact of heavy rains. Crews work to prevent rainwater from getting into the sanitary sewer system and are out investigating our system soon after a storm ends.
Additional Resources:
Wastewater treatment plant process
Why does wastewater cost more than water on my bill?
How does CLTWater respond to a wastewater overflow?
What does a growing city mean to wastewater treatment plants?
Is the odor from a wastewater plant or sewer manhole?
Construction, Repairs and Spills, Water Quality
April 3, 2023 Cam Coley CLTWater Communications
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.
Construction, Repairs and Spills
March 13, 2023 Cam Coley CLTWater Communications
With more than 4,500 miles of drinking water pipe, there is always something to fix. Customers can help by calling 311 or 704-336-7600 when they see or suspect a water leak or water main break. Even after the 311 Call Center is closed customers can say or select ‘water emergency’ to reach our dispatchers 24/7.
Charlotte Water prioritizes leaks so that crews repair emergency leaks first.
The Numbers
• 2,000+ repairs per year. Most are service line repairs (between the water main and meter box).
• There are multiple pipes under major roads (serving immediate areas and zip codes).
• Less than 10% of water pipe infrastructure is over 50 years due to proactive pipe replacement efforts.
Water Pipe Repair Step-By-Step
Investigate
Within hours, a field technician investigates and attempts to repair if it is an easy fix. If it is a leak that requires a construction crew, the technician prioritizes the leak based on severity. Many repairs require coordination with other departments or towns to minimize the impact on customers or drivers.
Locate
Call NC811 to have other utilities spray paint where their pipes / cables are before digging begins. This can take hours.
Isolate
Crews turn valves to stop water flowing through the leaking pipe. Crews may attempt to repair the pipe while keeping water in service for customers. Cones and barriers are set up to protect workers.
Excavate
Crews will uncover the pipe to make repairs or replace a section of the pipe. Crews will hand-dig portions to reduce the chance of damaging underground infrastructure.
Restore Water Service
Fire hydrants flow to test water quality before restoring water service to customers.
Repave and Reopen
Crews will backfill soil into the trench, test compaction, and then repave the road.
Restoration
Straw is placed over dirt if the repair is in a yard. A separate crew or contractor will return several days or weeks later to complete restoration efforts.
What other factors may extend the time between reporting a water leak and the repair?
Crews attempt to repair leaks without a water outage when possible and if there is time will work on solutions to minimize the outage.
Challenges underground
- Other utilities (fiber, storm water pipes) conflict with the repair and need to be replaced or moved including a large excavation area.
- Pipe requires full replacement including cutting it out and inserting a new pipe.
- Repaving depends on the weather. Air temperature is required to be a minimum of 40 degrees and rising in order to properly install asphalt.
Reducing impact on customers
- Coordinating with Charlotte Department of Transportation, North Carolina Department of Transportation, and/or towns to plan the repair to minimize detours during high traffic times.
- Installing new valves to minimize the number of customers affected by a water outage.
- Above ground water pipes may be installed to serve customers if the pipe replacement will take several days to complete.
What caused the water main break / leak?
Unfortunately, since water main breaks occur underground, in most cases we can only speculate as to how exactly the pipe broke. Here are some factors:
- Construction crews hitting mains while digging for other projects.
- Call 811 before you dig to locatethe pipes
- Temperature changes that can cause the soil to expand and contract,putting stress on pipes.
- Sudden change in water pressure. Quick use of a hydrant to fight a fire or a water main break nearby can cause other pipes to leak.
- Weak seals or a weakness where two pipes are joined together.
- Soil conditions (movement, corrosion, extra soil on top pushing down on pipes)
What causes a water main to break?
There are several factors that can cause a pipe to break, including change in temperature, age and external damage.
Who should I call if I see a leak?
If you see or suspect a leak, call 3-1-1 or 704-336-7600 so that Charlotte Water can quickly dispatch a crew to the location. Our dispatchers are working 24/7 so even after CharMeck 311 is closed you can say or select water emergency after the audio greeting to reach our staff.
Learn more at
- Employee Profile: Crew Chief Restoring Water Service
- Large Meter Repair
- Cold Weather and Water Main Breaks
- How to Protect your pipes during the winter months
“Every day, Charlotte Water routinely repairs and maintains water and sewer pipes across our entire service area,” says Charlotte Water Director Angela Charles. “It’s important that we are doing all that we can to keep customers’ trust in our ability to provide clean, safe and reliable water service to the Charlotte region.”
To stay up to date on the most recent events and announcements, follow Charlotte Water on Twitter @CLTWater. For more information on other pipe replacement and restoration projects, visit us at CharlotteWater.org.
