Category Archives: Construction

Photos of Water and Wastewater Construction

This blog provides general information about what to expect during construction. This is not comprehensive and may not include all equipment or construction situations.

Water and Wastewater Terms

WATER

Service Lines are the pipes between the water main under the street and the water meter. Sizes are ¾-inch or 1-inch in diameter at the meter box.

Water Mains (also distribution mains) are the pipes under the street that serve immediate customers and neighborhoods. Sizes range 4 to 12-inch diameter pipe along public streets or appropriate rights-of-way used for distributing water to individual customers.

Transmission Mains are the pipes under the street that serve several neighborhoods and zip codes. Sizes range from 16-inches in diameter to 72-inches.

WASTEWATER

Laterals convey wastewater (sewage) from an individual building to a gravity sewer pipe in the road right of way or a Charlotte Water easement.

Manholes are the access points for inspecting and maintaining wastewater pipes.

Low-Pressure Sanitary Sewer (LPSS) helps push wastewater away from properties near steep and uneven topography (usually near lakes and creeks).  Properties with this special need also have specialized maintenance needs. 

Trunk receives waste from laterals and conveys wastewater under the street or behind buildings along easements.

Interceptor is a large pipe that gathers wastewater from other trunks or collector pipes to convey to a wastewater treatment plant. Sizes range from 8-inches in diameter to 30-inches.

Relief Sewer is a large pipe to assist the existing interceptor when flows are reaching capacity. These pipes help prevent sanitary sewer overflows (SSOs) especially during heavy rain events. Sizes range from 12-inches in diameter to 78-inches.

Force Main & Pump Stations (also known as lift stations) pump neighborhood(s) wastewater from one creek/drainage basin to another through force mains to gravity flow sewer lines so that it can be conveyed to a wastewater treatment plant.

Project Types

  • photo of Crews installing new pipe to replace older pipe.
  • photo of men helping lower a blue pvc pipe into a trench for a water main replacement
  • photo of Crew cleaning underground pipe while customers are served with an above ground pipe.
  • Crews will be on scaffolding installing a sock-like lining inside an existing pipe through manholes. The sock-like liner will extend the wastewater pipe’s service life minimizing construction in the area.
  • photo of project inspector inspecting developer funded projects
  • photo of Meter and meter box installed for a new customer.

Capital Investment Plan (CIP)

Projects identified and budgeted through the Capital Investment Plan. These include projects to serve growing service areas, enhancements at water and wastewater treatment plants and other facilities, and to reline/replace old pipes. Size of equipment and construction zones will vary.

Pipe Replacement

Replacing the water main and/or service pipes (between the water main under the street to the water meter) to reduce future leaks/repairs due to age. Typical construction zone is a few street blocks.

Water Rehabilitation

Crews clean inside of 50+ year old pipes in the oldest neighborhoods. A temporary above-ground drinking water pipe may be installed.  Above-ground water pipes serve customers while the water pipe under the street is cleaned and relined with an epoxy solution. All pipes are tested for water quality. A typical construction area is several street blocks.

Wastewater Rehabilitation

Crews clean inside the pipe and install a

sock-like lining inside an existing pipe through manholes. Think of it as a new pipe inside the old pipe. The construction area may be in the street or the backyards.

Developer ‘Donated’ Projects (Installation Development Services, IDS)

Developers install new water and wastewater pipes and then donate to CLTWater.
CLTWater inspects pipe installation and tests pipes.

New Service Tap, Street Main Extension

Customers currently on well, septic, or developing a vacant lot can apply for water or wastewater service if it is within 1,000 feet of their property. Extending the pipe to serve a new customer may take months, depending on the location of the existing infrastructure and required permits.

What To Expect Before Construction

photo of two surveyors using equipment to take measurements that will help design a water or wastewater extension project.

Surveying

Survey crews determine the required depth for pipes by calculating the elevations in the area. Stakes, brightly colored flagging, and paint marks may appear in your yard or on the street after a survey crew has worked.

crew blowing smoke into a wastewater manhole to find any cracks in the wastewater pipe.

Smoke Testing

Crews may blow smoke into wastewater pipes to identify potential pipe cracks (where smoke escapes). Customers will be notified in advance.

photo of a large equipment used to assess soil and rock conditions so contractor can be more prepared for where to expect rock along the pipe alignment.

Soil Boring

Subcontractors may conduct subsurface investigations (also known as test pit or soft dig) to assess existing utilities as well as soil and rock conditions along the pipe alignment.

photo of a person spray painting or locating the underground utilities before a contractor begins digging.

Locates (Spray Painting)

Utilities spray paint where fiber optic, gas, and water pipes to inform contractors before  they dig.

a black fencing between the construction zone and private property to prevent soil or sediment from washing away.

Silt Fence

Silt fencing prevents soil /sediment from washing away.

photo of chain link fencing with a screening fabric.

Fencing

Security and privacy fencing may be installed.

photo of a small flag with charlotte water logo.

Ribbons, Stakes, & Spray Paint

The project area will have various markings along the pipe alignment.  Trees may be labeled differently. Please talk to the project manager or inspector to confirm what markings may mean for the project.

large equipment used to clear trees and bushes that are in the construction easement.

Clearing

The easement and temporary construction easement will be cleared of trees (with some exceptions) and restored to grass after pipe installation. CLTWater will preserve trees if possible.

photo of the top of a wastewater manhole with area cleared around it and trees on the sides. the area is being restored back to grass after construction.

Easement

The easement for a project will vary based on size of pipe, required depth, and other factors.

photo of a semitruck delivering pipes. a backhoe is taking them off the truck and stacking them in prepartion fro

Pipe Delivery and Storage

Pipe, equipment, soil and other materials are stored in the construction easement or road right-of-way.

a photo of a man helping a trackhoe lift a 48-inch water pipe off a tractor trailer.

48-inch drinking water pipe delivered to a construction area.

several pipes laying beside the street.

6-inch drinking water pipe along the side of the road during a water pipe replacement project.

What To Expect During Construction

a photo of two large excavators digging in a park with a mound of dirt behind them.

Construction Zone

Construction zones will be large enough for excavators and dump trucks to move.

a photo of a trackhoe digging up the middle of the street

Trackhoe & Backhoe
Excavators use a bucket on a hinged boom to remove dirt in the middle of the road for a new 36-inch pipe.

a photo of a backhoe in use with cones as flaggers help drivers around the construction zone, smaller than the  previous photo.

Crews using a backhoe at a water pipe rehabilitation project

a photo of equipment used to cut asphalt

Asphalt Cutter & Impact Hammer

Equipment used to break or cut asphalt to expose the pipe.

a photo of equipment used to break asphalt

a photo of a man looking at engineering plans for construction. the man is a construction inspector.

Inspectors

CLTWater inspectors will verify that pipes are installed in accordance with the design and assist customers.

a photo of an excavator dumping dirt into a dump truck.

Dump Trucks

Several dump trucks may assist with construction to remove and add soil, gravel, etc.

a photo of a trench box in a trench with a person working inside the box.

Trench Box

Trench boxes protect workers from cave-ins while installing, inspecting, or replacing pipes in the trench.

Wastewater Pipe Construction

a photo of two large excavators on a road that is closed for construction for a large wastewater pipe installation.

Large Equipment

24-inch wastewater pipe project under a street.

a photo of construction equipment driving over a creek that continues to flow via storm drain pipes.

Creek Crossing

Contractors may create a safe creek crossing for equipment. Large pipes keep the creek flowing underneath.

a photo of crews are lowering the top of a wastewater pipe manhole.

Manholes

Manholes vary in size depending on the amount of wastewater generated by a community.

Drinking Water Pipe Construction

a photo of two men using a valve key to turn water off to repair a pipe.

Valves

Crews may use drinking water valves to temporarily turn off water to a pipe.

a photo of crews flowing water from a fire hydrant after a repair.

Fire Hydrant Flushing

Crews may flow hydrants to test or maintain water quality.

photo of Meter and meter box installed for a new customer.

Meter Box Installation

A new water service installation includes: pipe near the property line, meter, and meter box. The property owner is responsible for connecting plumbing to tailpiece leaving the meter box.

a photo showing a fire hydrant including the exposed pipe and valve that are typically under ground.

Fire Hydrant Installation or Replacement

Fire hydrants are installed to provide emergency water service.

photo of 72-inch water transmission pipe to serve several neighborhoods.

A 72-inch water transmission pipe to serve several neighborhoods.

a photo of a 24-inch water pipe being lowered into a trench with a crew member watching it.

24-inch drinking water pipe installation.

a photo of a crew member on one side of the street working with crew on other side to install water service pipe under the pipe without trenching the entire street. a small backhoe or excavator can be used for a typical water main replacement or service line replacement project.

6-inch drinking water pipe replacement project, including new service pipes to each water meter.

What Does Tunneling (Boring) Look Like

a photo of a large tunneling operation installing wastewater pipe under a busy street. The photo includes a large pit or trench with tall trenchboxes, a trackhoe, crane, fencing and materials needed to tunnel underground.

CLTWater may tunnel under major roads to reduce lane closures. Tunneling requires entry and exit pits. Tunneling takes several months to complete. Some boring operations may be smaller to go under a large tree or driveway.

a photo of a large tunnel boring machine being lowered onto a tractor trailer.

Tunnel Boring Machine (TBM)

Some tunnel boring machines uses disc cutters to fracture rock.

a photo of a tunnel boring machine inside a pit with ladders to get down to the tunnel.

Tunnel boring machine at the bottom of the photo.

a photo of a man connecting a hook to a metal casing as part of tunneling process.

The pipe is installed inside a metal casing to
protect the pipe, the street, and other infrastructure above the tunnel.

a photo from inside a tunnel looking back at the entry pit or hole where someone is working.

View from inside the tunnel looking at the entry pit.

Cranes may be required to move equipment and dirt.

Cranes may be required to move equipment and dirt.

What Does Rock Blasting Look Like?

a photo of an excavator is lowering heavy matts in preparation for blasting.

CLTWater may contact customers to conduct a pre-blast survey to record building details.

A seismograph monitor records blast vibrations to
verify they are within safe specifications.

Blasting is a standard construction procedure for removing rock when other methods are not effective.

Holes are drilled to insert the dynamite charges into the rock.

Residents may hear a warning horn, a muffled noise, and slight vibration or rumble similar to a slammed door or thunder.

What Does Water Rehabilitation Look Like?

When pipes exceed 50 years of service, CLTWater can extend their service life through rehabilitation. Crews will clean and add a new interior lining. First, the contractor will install a temporary above-ground drinking water pipe and test it for quality. Once the above-ground pipe is approved, customers are connected.

What Does Wastewater Rehabilitation Look Like?

Crews will be on scaffolding, installing a sock-like lining inside an existing pipe through manholes. The sock-like liner will extend the wastewater pipe’s service life, minimizing construction in the area.

What Does Restoration Look Like?

  • wastewater pipe construction inthe street with two excavators with a ternch.
  • restored area showing repaved road and new grass
  • All construction and restoration by CLTWater contractors includes a one year warranty.
  • Subcontractors or Charlotte Department of Transportation (CDOT) Street Maintenance may repave a larger area than the trench after the project is complete.

What Do Charlotte Water’s Visible Utility Structures On Private Property Look Like?

  • Fire hydrants are installed within 1,000 feet of every existing property served by Charlotte Water.
  • photo of a water sampling station (green) The purpose is to monitor quality of water within the system.
  • photo of grass and two circles in the lawn that are the meter lids so that crews can turn water off to a water pipe to replace or repair a pipe.
  • Auto-flushers are used on dead ends or locations to flow water where water flow isn’t optimal to maintain excellent water quality.
  • Manholes are installed flush with grass if in a maintained yard. If the manhole is installed in a floodplain, it may have a vent coming out of it or may be raised.

Accomplishing two goals with one project

Adding Capacity at Rocky River Wastewater Treatment Plant and Moving More Water Back to the Catawba River

Clarke Creek Pump Station and Force Main Project

An average of 87+ million gallons of wastewater is treated and discharged each day from CLTWater’s wastewater treatment plants. Another 4.96 million gallons a day flows from northeastern Mecklenburg County to the Rocky River Regional Plant (owned and operated by the Water and Sewer Authority of Cabarrus County [WSACC]). Learn more about the agreement between CLTWater and Cabarrus County at CLTWater.org.

In 2021, CLTWater reached the maximum limit of permitted wastewater flow into the WSACC system. One of the steps to reduce flow was to move more wastewater to McDowell Creek by constructing a pump station in the Clarke Creek basin. The wastewater from these customers would naturally flow downstream to Rocky River, so CLTWater built a pump station to push the wastewater across the ridge line back to the Catawba River. The wastewater flows along pipes beside McDowell Creek until it reaches the McDowell Creek Wastewater Treatment Plant.

Facts
+ 2.5 million gallons a day pump station at peak. Started at more than half a million gallons of daily flow.
+ 21,812 feet of force main pipe
+ 7,000 feet of gravity sewer

McDowell Creek Wastewater Treatment Plant Improvements

Engineers also needed to ensure the wastewater plant’s readiness before adding more flow. CLTWater invested in multiple enhancements at the wastewater treatment plant so operators would be ready for the increased flow and replaced equipment that is at the end of its useful service life.

An excavator filling a dump truck at the pump station.

How CLTWater Repairs Leaks Under Highways, Interstates

To serve customers, CLTWater has water pipes under most roads, including crossing under highways and interstates.

So what happens when there is a leak or a necessary repair under a highway or interstate?

It starts with a lot of planning and preparation.

Teams of engineers and crews investigate the scope of the repair and begin working with the Charlotte Department of Transportation (CDOT) and the North Carolina Department of Transportation (NCDOT) to minimize impact on drivers.

Example: In the fall of 2024, crews installing a new pipe under Interstate 85 found excessive water entering the tunneling pits. Investigations revealed two underground leaks and cracked asphalt, which showed signs of water damage.

  • The team worked on an emergency plan.
  • At least one lane was closed on the interstate from 9:00 pm until 6:00 am Monday through Friday for at least a month.
  • Ground-penetrating radar (GPR) scans of each lane of the interstate helped identify the location of leaks and voids under the asphalt.
  • Stabilizing foam was injected under multiple lanes. More than 600, ¾ inch diameter holes were bored and injected to stabilize the subsurface.
  • The pipes were investigated from the inside using robot cameras. The pipes were in good condition, but some seals needed to be temporarily installed to keep them in service.
  • New pipes were installed inside the existing pipes to maintain use and minimize leaks.


Additional Resources:
How Charlotte Water Repairs Water Pipe Leaks | Charlotte Water Blog

Making the Most of Biosolids: Affordable Moves Toward Sustainable Biosolids Use

Based on an interview with Giovanna Forti Portiolli, Charlotte Water’s Resource Recovery Manager

Charlotte Water manages the largest public water and wastewater utility system in the Carolinas, serving more than one million people across Mecklenburg County. With five water resource recovery facilities (WRRFs) treating a combined average of 86 million gallons per day, the system also produces a significant amount of biosolids, about 120,000 wet tons per year. Traditionally, most of this material has been sent for beneficial reuse through land application, but rapid regional growth, tight storage capacity, and operational challenges have made that increasingly difficult.

I sat down with Giovanna Forti Portiolli, Charlotte Water’s Resource Recovery Manager, to discuss how Charlotte Water has navigated these hurdles without relying on significant immediate capital investments. Instead of waiting years for large-scale upgrades, her team found creative, collaborative, and cost-effective solutions that keep biosolids moving toward beneficial reuse rather than landfills.

Below are the key strategies and outcomes her team has piloted across our facilities.

Tackling Foreign Debris with a Sludge Screen Pilot at Irwin Creek WRRF

For almost two years, all of Irwin Creek’s biosolids were being landfilled out of precaution when the team started observing foreign debris finding its way to the final biosolids product. Landfilling biosolids is expensive, not sustainable, and wasteful of important nutrients and organic matter.

The operations team piloted a rental sludge screen to fine screen foreign debris out before dewatering the sludge. The impact was immediate. The utility was able to go back to beneficially reusing and recycling nutrients and organic matter from the biosolids, while also saving on landfill tipping fees. Renting the equipment also gave Charlotte Water time to test, refine, and validate the technology before purchasing and installing a permanent unit. This is a key example of how improperly disposing trash at home can have a direct negative impact in the community (e.g., higher costs and wasting important resources).

The image shows three columns of debris found in Biosolids. The columns are Nurdles/Pellets, Labels/Stickers, and Hair, from left to right.
Examples of debris causing this specific issue
Finding Storage Space

Biosolids storage is a valuable and often expensive resource to expand. Instead of launching a multimillion-dollar capital project, Charlotte Water took a more resourceful approach by looking inward at what already existed.

At Charlotte Water’s largest wastewater facility, McAlpine Creek Water Resource Recovery Facility, staff identified old, unused, or obsolete equipment inside the Residuals Management Facility that could be safely demolished to free up staging areas for future use. This newly reclaimed space eased bottlenecks and reduced the strain on limited storage. The effort generated savings of at least $135,000 every year.

A cleared-out space in the Biosolids storage. A large concrete space with barriers on the sides give potential room for biosolids. A truck has its lights on in the distant background of the facility.
Cleared out room for Biosolids storage
Strengthening Contractor Partnerships and Diversifying Outputs

Biosolids management is a shared effort. Charlotte Water works closely with its biosolids contractor to haul and land apply material, and Giovanna emphasized how important that relationship became during this transition.

Together, the team is exploring new outlets for beneficial reuse, including adding the ability to send a portion of biosolids to a composting facility. Furthermore, team is currently studying additional beneficial use outlet alternatives (e.g., alternative landfill daily cover, stormwater research). Additional reuse pathways reduce dependency on a single outlet when weather or operational conditions limits traditional land application. This adds more flexibility during challenging periods

To the right in the image a machine used to apply Biosolids onto land is spraying and distributing biosolids throughout a field. The sky is blue and there is a line of trees in the background.
Land application of Biosolids
Shifting to Seven-Day Dewatering at McAlpine Creek

For years, McAlpine operated on a five-day, twenty-four-hour dewatering schedule. This schedule created added operational pressure and challenges. The operations team transitioned to continuous seven-day operations, which streamlined biosolids flow and optimized every part of the process.

The change improved equipment efficiency, translated into a slight increase in cake solids, which help utilize storage more effectively. Even a small improvement in cake solids can reduce haul volumes and strengthen land application operations.

A Bigger Picture: Innovation Without a Giant Price Tag

All of these efforts share a commonality. Instead of waiting for long-term capital funding, staff, contractors, and consultants collaborated to identify practical, low-cost improvements that delivered benefits immediately.

Each strategy followed the same pattern:

• Start small

• Pilot first

• Measure everything

• Scale what works

And above all, stay open to ideas that come from every level of the organization.

These low-cost wins demonstrate how Charlotte Water is continuing to guide biosolids management toward higher efficiency, sustainable environmental outcomes, and reduced landfill dependency, while serving one of the country’s fastest-growing regions.

For questions, you can email Giovanna.FortiPortiolli@CharlotteNC.gov