Where There’s Smoke ...

The Municipal Pipe Tool Co. uses a simple testing protocol to identify sewer leaks – which often become repair business opportunities

The Municipal Pipe Tool Co. Inc. is an established and diversified firm, offering maintenance and trenchless rehabilitation for sanitary and storm sewers and conducting infiltration and inflow studies throughout Iowa and surrounding states.

The company, based in Hudson, Iowa, has offered smoke testing for almost 40 years. Though it accounts for less than 1 percent of annual revenue, smoke testing provides an important component in the company’s arsenal of diagnostic tools. Because the tests require only a blower and a source of smoke, testing can be offered without tying up investment capital.

The company was founded in 1963 as a sales agent for Sewer Equipment Co. of America. It began servicing sewer and water lines in 1967 with the formation of Vic Gearheart & Son.

An early adopter of technology, the company purchased one of the first waterjet machines west of the Mississippi and owned and operated one of the first CCTV sewer inspection systems in the area. The son in the company name was Steve Gearheart, still a consultant with the firm.

“The televised inspection was very primitive,” says Gearheart. “We were shooting in black-and-white, and as we moved the camera, the light bulb would crack and the camera would leak. It would sometimes take three to four passes to complete an inspection, and we would take Polaroids of the television screen to present to clients.”

Smoke rising

The company became involved in smoke testing in 1972 with the advent of the federal Clean Water Act. “Smoke testing was an easy and cost-effective way to find the sources of extraneous inflows into the sanitary system,” says Gearheart.

“When you’re looking for a sewage leak, the rule seems to be that you find it under the last stone left unturned, and smoke testing leaves no stones unturned. I’d estimate that the number of cities that don’t have a problem with inflow and infiltration at the bottom side of 10 percent.”

Municipalities were eager to request the service, because federal incentives reduced the cost of smoke testing to about 10 cents on the dollar. Municipal provides collection system management services to more than 200 communities in Iowa, Minnesota, Illinois, Nebraska, South Dakota, Missouri and Wisconsin in a territory that covers a radius of about 150 miles.

The initial flurry of smoke testing engagements gave way to a more moderate pace. Gearheart recommends that municipalities smoke-test their systems at least once every 10 years to help to assess pipe degradation. Besides being prudent, that establishes a routine compliant with EPA recommendations for collection system maintenance.

“Smoke testing isn’t the only way to go, but it’s one of the tools we have available in our toolbox,” Gearheart says. The company also provides smoke testing to industrial and residential clients, but these calls are less common.

Weather-dependent

Smoke testing can help trace uncapped or abandoned lines as well as detect leaks. For example, the company used smoke testing to help a John Deere manufacturing plant in Cedar Falls map out its sewer system. Recent one-off clients include a high-rise apartment complex and a church.

The smoke testing season is limited to snow-free months. Frozen soil and snow cover impede the passage of smoke, masking pipe leaks. June and July are prime months for smoke testing, although the company has tests as late as December. No license or certification is required for smoke testing, so the company differentiates itself through professional conduct and results.

“Conducting a proper smoke test requires industrial blowers and consistent smoke production,” says Todd Patterson, operations manager. “We’ve heard of contractors just tossing smoke bombs down a manhole and hoping for the best, or using a residential window fan to blow the smoke around. That’s just not going to do anything for the client. I’ve also heard of smoke bombs used in unventilated sewers, where the bomb has ignited the gas and blown off the manhole covers for several blocks around.”

The market for smoke testing equipment and supplies is limited to a few major players. Municipal Pipe purchases most of its equipment and supplies from Superior Signal Co. Inc., a company with almost 50 years invested in commercial smoke supply sales. “They’re reliable in their deliveries, and they’re very consistent with supplying and updating their Material Safety Data Sheets,” says Patterson.

Marking air movement

Smoke testing is almost a misnomer for the process: It’s actually an air-pressure test. Air is forced into the system at 800 and 4,000 cfm, and the smoke marks the movement of the air.

To create air pressure, Municipal Pipe crews use a Superior Signal Model 30-S/L Blower that fits over a sewer manhole. The gasoline-powered unit works with either petroleum-based liquid smoke or water vapor smoke candles (on smaller residential jobs, the contractor uses an electric blower, the Superior Signal 5-E).

The blower is started before insertion into the manhole to avoid creating sparks that may ignite sewer gases. Smoke testing for municipalities usually requires a three-person crew, which typically covers about 10,000 linear feet of line per 12-hour shift.

Once the smoke is generated, the team disperses along the length of the lateral flow, two scanning the right and left sides of the street, while the third member walks down the center, examining the street and catch basins. When they detect leaks, they record them on video for the client.

“Some clients expect to receive photographs of the testing, but I always tell them that shooting video is so much better,” says Patterson. “On a still photograph you can barely make out a wisp of smoke, but on a video you can actually see it moving. It’s the difference between night and day.”

The crew can also train the video camera on street addresses and nearby intersections to help clients pinpoint the location of the leaks.

Ready to repair

If smoke testing uncovers a leak or other problem, Municipal crew members can often repair the defect. “If it’s something we can help with, we’re right there to fix it,” says Gearheart. The company has a substantial fleet of cleaning, inspection and repair equipment that includes:

• Four Camel combination trucks from Super Products LLC.

• One combination sewer cleaner from Vac-Con Inc.

• Three inspection vans from RS Technical Services Inc.

• A grout van from Telespector.

• Three TV inspection and lateral reinstatement vans, two from Aries Industries Inc., and one from CUES Inc.

• A manhole rehabilitation trailer from AP/M Permaform.

• Four boiler trucks, two refrigerated trucks, and two refrigerated trailers used for cured-in-place pipe lining.

• Six waterjet trucks, four bucket machines and three duct rodders from SRECO-Flexible.

The company has three crews devoted to trenchless repairs. Structural defects are repaired with cured-in-place liners going manhole-to-manhole for lengths of 3 to 50 feet. If repairs can’t be completed using trenchless methods, an excavation contractor is called in.

As needed

Gearheart says that the company doesn’t advertise smoke testing except on its Web site or as part of presentations at seminars given by the Water Environment Federation and others. Smoke testing is offered mostly on an as-needed basis or as an adjunct to collection system management services.

“When I’m talking to a client who says their flows go ballistic after a 1-inch rain, I’ll ask them, ‘Have you ever smoke-tested?’” says Patterson. “It’s not something the client will usually ask for themselves, so we have to be the ones to offer it.”

While locating pipe leaks through smoke testing doesn’t guarantee the company will earn a repair contract, it helps Municipal to promote itself as a knowledgeable, full-service enterprise offering the right diagnostic tools for the right job.



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