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Should you ditch the dig?

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Should you ditch the dig?

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    Which repair/rehab method do you use?Cured-in-place piping ranked highest for methods to repair or rehabilitate pipe. No respondents use pipe eating. Source: PUBLIC WORKS

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    Crews set up a boring pit to jack a casing into place under Interstate 80 in Illinois for water and sewer installation. Photos: Pam Broviak

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    This boring head and auger is used to penetrate soil and convey it back to the receiving pit. Special rock heads are also made to penetrate solid rock.

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    Built-up scale in water lines can be removed through the use of trenchless methods such as air scouring and pigging.

Not just for sewers

Horizontal directional drilling on the rise for water lines.

Although trenchless methods like pipe jacking have long been used to install water mains, the use of plastics such as high-density polyethylene pipe has expanded to embrace horizontal directional drilling (HDD) and other methods. According to results of an exclusive PUBLIC WORKS survey, HDD has been used most frequently (80%) in new construction.

HDD also showed the largest satisfaction rating for rehabilitation or new construction—28% of respondents rate their experience as excellent, 43% as good.

HDD can be preferable to pipe-jacking because of the ability to place the pipe within a wider range of elevation change. “With the use of flexible rods, we can steer the pipe through a vertical distance of 21 inches within 30 feet,” says Jared Wintermyer of Leon E. Wintermyer Inc., a construction company based in Etters, Pa.

Trenchless methods also are used to clean and rehabilitate existing lines. Structural and nonstructural liners extends useful life by 50 to 75 years. Processes such as air scouring and pigging can be used to rejuvenate pipes that are still structurally sound and only require a removal of built-up scale.