Sliplining Gives Louisville Water a Solution

Louisville Water is conducting the largest main replacement program in its history, with minimal impact on local residents.
Sliplining Gives Louisville Water a Solution
New sections of pipe are staged for sliplining along the Eastern Parkway Project in Louisville.

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Infrastructure replacement projects tend to draw the ire of anyone who is inconvenienced by traffic delays or service interruptions, but Louisville Water has found a way around that.
The Louisville Water Company is replacing 6.4 miles of old cast iron water main in the midst of the city, and doing so with a surprisingly minimal impact on affected neighborhoods.
The $23 million Eastern Parkway Project follows a busy tree-lined boulevard that features historic homes, spacious yards, parks and commercial developments. The project’s success is predicated on three main points:

  • The work is taking place in three phases during winter months only, so that summertime water use — when demand is highest — is not affected
  • Citizens in the affected area have been closely involved in preconstruction communications and meetings so their concerns could be heard and plans shared
  • Perhaps most important, the old pipe is being sliplined with steel to avoid large excavations and major traffic disruptions

“We’re doing this without anyone losing water,” says Kelley Dearing Smith, vice president of communications and marketing for Louisville Water. “We are keeping Eastern Parkway open. We are preserving the beauty and character of the area.”

Traffic detours are being kept to a minimum, she adds.

Out with the old

The old cast iron pipe is 48 inches in diameter and dates to the 1920s. Wall thickness is 1.75 inches, with sections joined by “leadite” — a  nonmetallic resin. It carries water from the Crescent Hill water treatment plant to a 25-million-gallon underground reservoir, and has experienced a number of breaks over the past few years, three major breaks only recently.   

“We examined the pipe using robotic technology from Pure Technologies,” explains Mike Meyer, project manager for Louisville Water. “The technology looks for leaks, air pockets, and pipe wall stress areas.”

“We also televised it,” Meyer adds. “The breaks were not in the walls themselves, but at the joints. There were breaks where the joints had cracked.”

Meyer attributes the cracks to stress brought on by temperature changes over the years. “The leadite joints expanded and contracted differently than the pipe itself.”

Once the decision was made to replace the 6.4-mile section of old pipe, Louisville and its design consultant, HDR, looked at alternatives.

“Opencut excavation would have been very disruptive,” Meyer says. That made sliplining the choice. Meyer says Louisville looked at a number of liners — including PVC and HDPE pipe, before settling on steel. “Our concerns were about wall thickness and inside diameter size,” says Meyer. “We didn’t want to lose capacity.”

In the end, Louisville went with a 42-inch O.D. steel pipe, to be inserted inside the old 48-inch O.D. host pipe. Meyer says the smaller bell and spigot size on the steel pipe also figured heavily in the analysis. “That allowed us to maximize the interior diameter of the liner pipe.”

Eastern Parkway is not only the largest water main repair project in Louisville Water’s history, it’s the first time the company has used sliplining. “Opencut would have been a nightmare,” Meyer says. “It would have taken much longer and caused more disruption.”

How they did it

Louisville initiated the first phase of the slipline project last fall, after awarding the project to Garney Construction, headquartered in Kansas City. In the process, the contractor digs 30-foot push pits at points where 25-foot-long sections of the liner pipe (supplied by American Steel Pipe) are to be inserted into the host pipe. Then, a hoist drops a jacking machine into the pit, where it is mounted on a set of rails. Spacers are attached to the pipe sections, and the sections are placed into the pit and pushed by the jacking machine into the old pipe. Inside the pit, the machine can also be turned around to push pipe in the other direction.

“The jacking machine is basically a jack-and-bore with the bore unit removed,” explains Meyer.

Where the pipe goes around sweeping turns or bends, shorter 10-foot sections of steel liner pipe are used. In the case of tight turns, the section is fully excavated and the old pipe is removed before the steel pipe is put in place.

Meyer explains that the sections are fitted together, and a welder enters the pipeline and physically welds the pipe sections together at each bell-and-spigot joint. The welds are then inspected, and the pipe system is chlorinated and pressure tested. First, it is filled with chlorinated water, which remains in the pipe for a period of 25 to 50 hours, and then is flushed out. Potable water is pumped into the piping and the system is pressure tested to 150 psi. Meyer says normal operating pressure is 90 psi.

Each section of steel pipe installed in the opencut trench areas has a poly liner on the outside surface installed at the factory to prevent corrosion. Pipe sliplined through the existing 48-inch pipe is not coated and left bare steel.  

Finally, the new pipe is grouted in place. Meyer says grout is pumped into the annular space between the outside of the liner pipe and the inside of the host pipe. “Grouting is last so that it doesn’t cause any false readings with pressure testing,” he explains.

Louisville prides itself on system redundancy, and there are several distribution connections along the Eastern Parkway water main that convey water to other specific areas. “We have multiple backups in place — a lot of redundancy — so we can remove the Eastern Parkway main from service while other mains pick up the water load,” Meyer says. Where those connections exist, the open pit method is used to replace the piping because it’s not possible to push the new pipe through them.

Community outreach

Both Meyer and Dearing Smith emphasize the important role that community involvement has played in the success of the project thus far.

“If there’s a takeaway, it’s communications,” says Dearing Smith. She says Louisville Water made sure that affected citizens had a chance to hear preliminary plans and voice their concerns at meetings before the first pit was dug. “It was important that we identify the stakeholders and get them involved early on so they would know what to expect. We had all vendors at the table as well. There were no surprises. It’s probably the most layered communications program we’ve ever done.”

Effective communication is more than just a press release. Dearing Smith points out that Louisville Water is using social media, its website, signage, face-to-face meetings, and even drone videography to facilitate the flow of information back and forth.

“We’ve had some complaints, but not as many as we thought we’d have. Most have involved vehicles speeding through the neighborhood.”

Traffic is a big deal with projects like this, but since Eastern Parkway is a four-lane boulevard with a wide median strip, disruption was minimized. While work took place on one side of the road, traffic was diverted to the other two lanes, traveling in both directions. In cases where complete intersections required work, they were shut down from 8 p.m. Friday to 6 a.m. Monday.

“We worked very closely with Metro Parks, Metro Public Works, and the Kentucky Transportation Cabinet on these plans and diversions,” says Dearing Smith.

Now that phase 1 is complete, citizens who will be affected by phase 2 — scheduled for next winter — can see what to expect. “We’re doing the site restoration in phases, too,” she says. “They can see the new curbs, pavement, trees and landscaping (that follow the pipe replacement).”

The next phase will pass through the University of Louisville campus, close to the school’s highly regarded engineering department. Dearing Smith sees this is an opportunity.

“The existing pipeline goes through the center of the campus,” she explains. “So we’re talking with the university about realigning the pipe and going through an area that they’ve just begun to develop.”

She envisions lectures, classroom presentations, photos in the campus library, and pipeline parties. “What better way to get the schools and the students involved in the project?” she asks.

As of April 1, Louisville Water was wrapping up the first phase of the sliplining project and preparing to put the Eastern Parkway water main back in business. And just in time.
“We have something pretty big here the first Saturday of May,” Meyer notes. “It’s called the Kentucky Derby.”

A big piece of history

For more than 100 years it was out of sight, buried underground in Louisville Water’s distribution system.

Soon, it will be on display for thousands to see and examine at Louisville’s Water Works Museum.

It’s an enormous water valve, 12 feet high and weighing more than 100,000 pounds, carrying a patent date of 1888.

According to Kelley Dearing Smith, public information officer for the Louisville Water Company, the valve was manufactured by the Rensselaer Valve Company in Troy, New York. It was installed along with the original cast iron pipe, which ran along Eastern Parkway and was discovered as crews worked to repair the Eastern Parkway water main.

Smith says the huge valve is being cleaned up and will soon be on display at the Water Works Museum, located along the Ohio River and dedicated to exhibiting the history of the water infrastructure that serves the area. The museum is located in the city’s original pump house No. 1, and includes the city’s first water tower on its property. Exhibits include historic photographs, films and memorabilia that demonstrate the company’s contributions to safe drinking water and innovations in science and engineering. Special exhibits rotate throughout the year.

Thousands of people visit annually, including students on field trips, group tours and individuals. The facility can be rented for weddings and other special occasions.

The historic valve will have some historic company when it’s placed in the museum. The exhibits also include a 1919 Allis-Chalmers pump.


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