Rehabilitating Stormwater Pipe

Credit: iStock/NUMAX3D

Growing in Orange County
Orlando, FL, is home to Cinderella’s Castle. It’s where 17.2 million visitors pass through the gates to Mickey’s house annually. Upon its opening in 1971, Disney World hosted some 10,000 visitors, all of them happy to pay the $3.50 admission to the Magic Kingdom. Today, that same admission price is upwards of $97.

Orange County, FL, however, is no longer known only as being the home to Walt Disney’s dream. Admissions to the theme parks are not the only prices that have sky­rocketed, either. In 2013, 1.225 million citizens shared the 1,000 square miles of the county (10% of which is water), making it the fifth most populous county in the state of Florida. Of the state’s $105 billion total global merchandise trade in 2013, $3.9 billion came from the Orlando-Kissimmee-Sanford region. Not only is it the most visited destination in the United States, but the life sciences and health care industries have expanded tremendously there as well.

In the decades since 1970, Florida’s population has grown by 134.6%. In the 1990s, record numbers of people entered the state, giving it the distinction of being the third consecutive decade that it grew by roughly 3 million. Orange County itself saw a 30% population growth. And from 2004 to 2014, the population growth continued until it exceeded Florida’s overall population growth.

In the booming 1990s, Orange County took a close look at its growing—and aging—water infrastructure to make decisions about maintaining and upgrading it. Officials knew they had to get the older infrastructure inspected and that repairs were necessary. They decided to contract outside their own stormwater department for making the repairs to the system. The Stormwater Management Division in Orange County has been through many changes since then. Today it employs approximately 104 different technicians, engineers, equipment operators, foremen, and inspectors, who are jointly responsible for the planning, operation, and maintenance of unincorporated Orange County’s storm and flood drainage systems.

The division includes 18 pump stations, 1,700 stormwater ponds, 95 miles of canals, 5 dams, 80 drain wells, and 50 major control structures. By working with outside contractors on some of the work, the county has been able to get the older infrastructure inspected, sewer lines cleaned, stormwater pipe relined, and manhole structures rehabilitated. Part of this work has been performed by local divisions of Insituform Technologies Inc., Plastic Composites, and Layne Inliner.

“We have multiyear, ongoing rehabilitation projects with Orange County on their combined wastewater and stormwater systems,” explains D. J. Wroble, senior vice president with Raven Lining Systems. “Insituform did the pipe, and Plastic Composites did the manhole rehabilitation work. Later, Layne Inliner did both pipe and manholes. And all of them sprayed Raven.”

Taking its name from the founder’s favorite poem, “The Raven” by Edgar Allen Poe, Raven Lining Systems is a leader in the water, wastewater, and manhole ­rehabilitation industry, and a supplier to many of the ­rehabilitation specialists.

Andrew Costa, business development manager with Insituform Technologies LLC, a subsidiary of Aegion Corp., says Orange County determines its needs and awards annual contracts. “In general, pipes eventually fail from a number of causes. Joints have issues; you get sinkholes. Pipes just deteriorate from erosion or corrosion.”

Insituform Technologies provides cured-in-place pipe (CIPP) technology and other services for rehabilitation of water and wastewater pipeline systems. From 2011 to 2014, Insituform relined 45,768 feet of stormwater pipe in Orange County. “We used a combination of installation methods,” says Costa. “Pipes in drier areas were installed with air inversion/steam cure [AISC], and those pipes that were fully submerged or ended in outfalls were installed with water inversion/water cure.”

After cleaning and preparation, Costa says, crews installed the standard Insituform CIPP lining tube, InsituTube. All installations were done per ASTM F-1216, the longstanding industry standard for CIPP design and installation. “Once the pipe is fully cured, if we used water to invert/cure, that cure water is cooled, and after the ends are cut the pipe is CCTV’d [inspected with closed-circuit TV technology] to document the final installation. Copies of DVDs and printed reports are then presented to the client.”

Photos: Insituform

Photos: Insituform

After Insituform finished with the CIPP relining, Plastic Composites of Mount Dora, FL, came in and performed the rehabilitation work on the manholes and boxes. Plastic Composites is a leader in concrete corrosion protection. Mike

Ashcraft, vice president with Plastic Composites, says the company used Raven 405 when rehabilitating more than 350 manholes in Orange County. “First we prep—according to Raven’s data sheets on preparation and depending on the manhole—open one grate, and set up our tripod and safety gear,” says Ashcraft.

After moving through the safety protocols, crews get down to the tougher work. “We use a Vac-Tron truck to vacuum out water and debris. We inspect the concrete structures to look for active groundwater penetration,” he says. “If there is a leak, we would take the following steps: Drill a three-eighth-inch hole in the concrete, and install an injection port. We will then inject Avanti 202-LV into the port, and allow it to flow on the backside of the pipe or structure. This will then activate with water and seal the leak off.” Avanti 202-LV is a low-viscosity grout.

Relining pipe in Florida’s Orange County with CIPP technology

Relining pipe in Florida’s Orange County with CIPP technology

If an inspection showed no leaks, crews rebuild the surface integrity by installing 0.5 to 1 inch of a cementitious resurfacer. After that cures, they profile it again at 5,000 psi and spray Raven 405.

Raven 405 is a two-part product that is heated in a special tank to be sprayed. This is not just any spray equipment. Plastic Composites uses a Graco XP plural-component sprayer that allows the Raven 405 components to remain separate while moving through the heated lines towards the “whip” and sprayer gun. It’s only right at the whip that it mixes and moves into the sprayer and into the flex gun for spraying.

Manhole rehabilitation often includes replacement of steps and other components. However, because the manholes the company rehabilitated in Orange County had none of those, crews didn’t have to deal with that aspect of the job. All of the Plastic Composites crews are trained in Florida’s Maintenance of Traffic (FMOT) control, so neither vehicular nor pedestrian traffic presented a challenge, either.

sw1701_35The biggest challenge, as would be expected in the South, was water. “It was the active infiltration of water. Always,” says Ashcraft. “The floors were eaten out, so we would sometimes have to mix up grout and fill in the holes and let it set up. Then we would go back in later and work. But that was all just part of the job.”

Layne Inliner, with corporate headquarters in The Woodlands, TX, has rehabilitated more than 450,000 feet of sanitary and storm sewers in Orange County using its CIPP lining techniques. Mike Cannon, P.E., with the Clearwater, FL division of Layne, says the projects included sewer cleaning, pre- and post-CCTV inspection, dewatering, bypass pumping, and manhole structure rehabilitation, utilizing the Raven Lining System. Pipe diameters ranged 8–84 inches. Layne Inliner has installed more than 18.9 million feet of CIPP throughout the US, with all of its installation techniques ISO 9001:2008 certified.

Working on the Train Lines
Claycomo, MO, is a small village in Clay County with a population of only 1,430, according to the 2010 census. It seems that little towns have their own special feature people remember about them. In this case, the town’s name seems to have been borrowed and reconstructed by what’s referred to as a portmanteau, a blend of multiple words that forms an entirely new word: Clay + Co+ Mo = Claycomo.

There are 100 or so businesses in the area, including Ford Motor Co., which manufactures the Ford F-150 pickup trucks at its assembly plant in Claycomo. Near 18th and Brooklyn Streets, there’s a railroad line with three tracks running at all times. With the commerce depends on the railroad, nobody wants these rails shut down.

The problem, however, was the infrastructure running under the tracks. Between 10 feet and 13.5 feet below the tracks was a 42-inch concrete storm drain. The pipes were breaking down and had cracks. The railroad recognized that this deteriorated pipe was potentially a serious problem.

“They had previously done an emergency liner, but that failed,” says Jon Foster, a project manager with Blue Nile Contractors in Claycomo. “They saw the major cracks and wanted to get it fixed before it collapsed.”

Blue Nile turned in a low bid on the job, but it was actually the company’s timeline that the railroad liked. “We could be in and out in 24 hours using the UV-cured liner,” explains Foster. “We bid it with the Reline America Alphaliner 1500.”

Reline America, located in Saltville, VA, is the only manufacturer of Alphaliner (formerly known as Blue-Tek) ultraviolet glass reinforced cured-in-place pipe (UV CIPP) in North America.

And the rest, as they say, is history. Foster’s company won the bid, and the crew went in to set up and get to work—just as any other day, right?

Maybe not.

Foster knew that he would have three railroad tracks to deal with—what he didn’t know was that two trains would be running on either side of the site at all times, while the crew was working.

Underneath the railroad tracks was an old creekbed, and on the sides were 15-foot, poured-in-place concrete walls that formed a ravine to stop rocks from falling in on the tracks. In preparing for the job, the crew looked for an access road and finally found a place they could possibly set vehicles down, but it was still 15 feet from the work site, says Foster. “About a third of a mile down, there was a ramp for trucks where we could maybe get vehicles on, but there was a big drop off. So we brought in a 90-ton crane that lifted the railroad track panels. These are cut out to allow access to the manholes, and they’re set about 150 feet apart. It ended up that the crane did a lot of the work for us.”

But, first the crew had to get the 90-ton crane onto the railroad track. On one side of the tracks they had a 20-foot-wide hill, and on the other side, 30 feet down, a valley. They decided to haul some of the dirt out from the hill to lower it and smooth it out so they could get the crane onto the tracks. “We hauled out 30 tri-axle dump truck loads of dirt!” says Foster.

To make things worse, on the same day that they began to prepare the site, it began to rain. It rained for hours and hours, Foster recalls. The crew set up two 8-inch bypass pumps and 1,400 feet of hose to stop the combined sewer and stormwater overflow.

“The crane area became a mud hole. The crane got stuck,” he says. “We hauled in two loads of rock to help get it out. We figured that would work. It took seven loads of rock.”

Eventually, the rain stopped, and they got the crane out and were able to get on with their work.

Starting upstream at what they called manhole number 5, the crew used John Deere tractors to lift the track and move it down to the junction box. They used the crane to set a trench box over the hole and to move an 8-foot by 20-foot street plate across the trench box and back over the manhole. They then moved all of the winches and equipment, along with the crane, to the next hole—four in all. “At that point, we’d spent 20 hours just getting debris out of the lines,” he says.

After all the cleaning, 600 feet of 42-inch liner was brought to the site.

Foster says, “We pulled the liner in, inflated it, and pulled in the light-train,” the piece of equipment used to cure the liner. “We took video to look for air bubbles in the liner, then we fired up the bulbs and pulled back the light-train.”

Foster says the thickness of the AlphaLiner 1500 for this job was 12.5 millimeters. For that thickness, the light-train is pulled back at 1.8 feet per minute. After the liner cured for six hours, the crew was able to pull the light-train out, grout the ends, and get ready to do the post inspection video.

All in all, Blue Nile rehabilitated 600 feet of 42-inch concrete pipe and never had to shut down the tracks. Compared to digging the pipe out, Foster says, the method saved the railroad millions of dollars. And when the job was finished, each truckload of dirt taken from that slope to get the crane in—all 30 loads— was returned to where it came from.

Credit: AP/M Permaform Stormwater pipe in Navarre Beach, FL, ran beneath a busy highway.

Credit: AP/M Permaform
Stormwater pipe in Navarre Beach, FL, ran beneath a busy highway.

When Challenges Come In After the Contract Bid
Each underground pipe rehabilitation project has its challenges, but it seems some crop up a little later—even after the contract’s original bid.

The Florida Department of Transportation had a fairly typical-sounding project along Highway 87 in Navarre Beach. The storm drain ran parallel to the highway. It consisted of a 48-inch corrugated metal pipe (CMP) located directly beneath the sidewalk and curb, along with some other utilities and lines one would normally expect. The pipe needed to be replaced.

Marshall Brothers Contracting of Lynn Haven, FL, originally bid the job as an open-cut dig and replace with a cost of $1.3 million. However, a change order of $1.5 million was added later because the original plans had not shown one of the sections of pipe extending into the main highway. This little glitch was a bit of a game changer in terms of digging and replacing large pipe along a major coastal highway in Florida.

John Lewis, vice president of L&R Contracting of Panama City, FL, worked as a subcontractor on the project. He explains the added pipe extension: “There was about 300 yards of pipe that was parallel to the highway, under the sidewalk, that you could see. But there was also about 100 feet that ran parallel along the sidewalk, and it was right in the travel lane of the highway.”

Crews would have about 100 feet of 42-inch concrete pipe to replace and about 1,346 feet of 48-inch CMP, all of which lay at a 14-foot depth. Lewis says the area had

such a high water table that an ­open-cut approach would have been difficult, and because of the location of the pipe, it would mean closing lanes on a major highway. The soil beneath the pipe had already begun to erode, likely because of the leaks from the pipe.

Marshall Brothers decided to seek an alternate method for both ­sections of pipe. Lewis reached out to Scott Benner, a CentriPipe ­applicator with Centrifugal Lining in New Jersey. CentriPipe, a product of AP/M Permaform, is a trenchless relining method.

“They would have had to close the road to remove and replace, and that’s with dewatering every inch along the way,” says Lewis. “To dig and replace that pipe, they would have to detour traffic. With this method, we only had one lane of closure for four days, in lieu of months and months of total detour and closure.”

The Florida DOT has a program called Cost Saving Initiative, whereby a contractor can propose an ­alternate method for a project that saves money for the state, and the state will basically split the savings with the contractor. (See sidebar.) Lewis admits he was not entirely familiar with the program at the time.

Florida’s Cost Saving Initiative

The purpose of changing the contract must be to adopt a more cost effective approach and a higher-quality end result. The contractor must call for a Cost Saving Initiative workshop to be held before the contract time actually begins. The contractor and the Florida DOT will then meet to discuss how feasible the proposal is.

The contractor must demonstrate that the proposed alternate method will result in savings without impairing safety, reliability, service, life, economy of operation, ease of maintenance, aesthetics, or necessary standard design features. However, contractors can change or eliminate features that are excessive or nonessential.

At the core of this program is a sharing arrangement that says that if the DOT approves the alternate method proposed, the contractor will receive “50% of the net reduction in the cost of performance of the contract as determined by the final negotiated agreement between the contractor and the department.”

A New Approach at Navarre Beach
Ultimately, L&R Contracting rehabilitated more than 1,300 feet of 48-inch CMP along Highway 87 with CentriPipe. “We use the CIPP for the smaller pipe, but for the big pipes we use CentriPipe. This is 8,000 psi cement mix, fiber-bonded and basically spun inside the pipe,” says Lewis.

AP/M Permaform began as Action Products Marketing Corporation (AP/M) in Johnston, IA, in 1985, rehabilitating manholes with its patented product Permaform. A leader in trenchless technology, AP/M has many products that can be used depending on the degree of damage to the pipe and what is needed to satisfy the client’s needs. CentriPipe is used to renew structural integrity of culverts and storm and sanitary sewer pipe from 30 to 120 inches in diameter; it provides waterproofing, sealing, and corrosion protection.

In Florida, water is always an additional challenge. The work was done during the rainy period, and the site was located at the lower end of a pond. When it rained, crews had to stop work and wait for the rain to stop. “The water table was also a big challenge,” explains Lewis. “It was a challenge to get them sealed because of the heavy water pressure.”

Once the pipe rehabilitation was done, Marshall Brothers patched and overlaid the roadway. “They came in and milled the existing asphalt and brought in new asphalt to lose that settled area,” says Lewis.

Utility Services Group The roadway above the damaged pipe;

Utility Services Group
The roadway above the damaged pipe;

When Sidewalks Cave In
Several small boroughs and townships lie 21 miles southeast of Harrisburg in northwestern Lancaster County, PA. The estimated 11,550 citizens of Elizabethtown Borough, like most of us, gave little thought to what was happening under their streets or sidewalks until one day when the road simply caved in.

The problem occurred on the main road that had a small drainage ditch running beside it. A corrugated metal stormwater pipe was located beneath the road, and the bottom of the pipe had worn away.

Robert Kalbach, president of ­Utility Services Group, says the problem had probably been developing for a period of time. “But funding is the driving factor,” he notes. “Gas blows up. Water gets bacteria in it and makes people sick. Stormwater really doesn’t impact people in that way, so it’s the least critical. It’s an out-of-sight, out-of-mind kind of thing. But it costs lots of money to repair.”

Credit: Utility Services Group The pipe before and after repair

Credit: Utility Services Group
The pipe before repair

Inspections were performed on the open-ended pipe to determine what could or should be done. Kalbach says the town’s first consideration was to remove and replace the entire pipe. That was before officials realized how costly such a project can be for a small community, not to mention how disruptive it is to tear up the main street in a quiet little town.

Utility Services Group, a family-owned contracting services group in Camp Hill, PA, that specializes in underground infrastructure, was asked to inspect and submit a bid for an alternate method of repairing the stormwater pipe. Kalbach chose MH Liner from Parson Environmental Products in Reading, PA. MH Liner is a high-strength fiber-reinforced, Portland-cement-based, microsilica-enhanced mortar.

Because the road already had a drainage ditch running alongside, says Kalbach, the main concern was to have adequate pumps to be prepared for rain events during the work. “We didn’t get any rain that I remember, but we still had to have everything there and be prepared just in case.”

Credit: Utility Services Group The pipe before and after repair

Credit: Utility Services Group
The pipe after repair

Since the bottom of the large pipe was fully deteriorated already, prep work involved cutting the pipe down to the good metal and thoroughly cleaning it, according to Parson’s surface preparation instructions.

Kalbach explains, “We high-pressure-water-blasted all the walls, then spray coated with the cementitious coating. It can either be sprayed or troweled and brushed. From there, it just has to be kept dry while it’s curing.” MH Liner can be applied to vertical, horizontal, or overhead surfaces with a 0.5-inch minimum thickness.

The community was able to maintain normal traffic while the pipe was repaired, says Kalbach. “The town was not impacted and that made them happy. And we stayed within budget.”

It’s always good to have a little cushion, even if it’s not used. Kalbach says that in the proposal, his company had allowed for a “rain day,” but there was no rain and so they were able to finish the job sooner than the contract specified. And they were able to save the town roughly half of what the original removal and replacement plan would have cost. SW_bug_web

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