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10:24 AM Tue, Nov. 20th

Prescott agrees to repair water pipeline; 3,000-foot section through Chino Valley needs dirt work

CHINO VALLEY – Prescott officials agreed Monday to dig up dirt surrounding a 3,000-foot section of their main water supply pipeline through Chino Valley, and re-compact the dirt.

Prescott, Chino Valley, Copeland Geotechnical Consultants and Arizona Department of Environmental Quality (ADEQ) representatives met Monday to resolve issues surrounding the section of pipe, which serves the entire City of Prescott.

Prescott Environmental Services Director Brad Huza said he will ask the contractor, Johansen Construction, to start reworking the section Monday. The work should take approximately a month, Huza said. Water will continue to flow to Prescott during the work.

Previous tests of other parts of the three-mile section of 36-inch pipeline that runs through Chino Valley have produced varying conclusions about the level of dirt compaction.

In a fourth series of soil compaction tests this past week that focused on 3,000 feet of the pipeline south of Outer Loop Road and just west of Highway 89, Copeland consultants found four voids, or air pockets, under and alongside the pipeline.

The voids are a definite indication that the work did not meet specifications, said Stu Spaulding, Chino Valley Public Works director. Those areas amount to zero-percent compaction when workers were supposed to compact the soil to a minimum of 95 percent.

The voids shocked him, Spaulding said, because Huza as the project engineer certified it at 95-percent compaction.

"We want it compacted to the specifications given to us by the City of Prescott," Spaulding said.

Substandard compaction of the pipeline could cause pipe welds to crack or leak, and continued settling of the trench as time passes could cause the pipeline to break and flood nearby homes and roadways, Spaulding said.

When Huza and Al Johansen checked out the 3,000-foot section Wednesday, Johansen agreed to recompact the dirt at his own cost, since the work still is under warranty, Huza said.

ADEQ will oversee the compaction work on the 3,000-foot section during the coming month, to make sure the process works, said Peter Foster, ADEQ liaison.

The landowner where that section sits has plans for development, and Chino Valley officials are concerned about damage to future roads if the soil below them isn't properly compacted, Spaulding said.

Copeland also was the on-call geotechnical contractor during construction of the $8.3 million pipeline, and Copeland official Brian Carpenter said Prescott did not ask the company to perform compaction tests in that 3,000-foot section along the south side of town.

Since Huza and Prescott City Manager Larry Asaro agreed in Monday's meeting to dig up the 3,000-foot section and re-compact it, Copeland doesn't need to bother working another two or three weeks to wrap up final test results on the level of compaction in that area, Foster said.

Prescott finished the pipeline in July 2000, and Chino Valley officials began expressing concerns by October 2000 when dirt surrounding the pipeline along Road 4 South collapsed after a heavy rain. Chino officials asked ADEQ to become involved in the process, and ADEQ since has been trying to mediate the review of the pipeline construction.

"It's their prerogative, it's their community, we've got nothing to hide," Huza said of Chino's request for ADEQ oversight and review. "My fear is what it's done for regional cooperation."

Approximately three miles of the 13-mile pipeline run through Chino Valley. ADEQ is waiting to see Prescott's proposal on what repairs the city might conduct on the remainder of the pipeline within Chino, Foster said.

ADEQ is reviewing Prescott's compaction tests on the remaining 10 miles of pipeline that run south through unincorporated parts of the county to Prescott, Foster said.

Prescott and Chino Valley officials still disagree about the quality of the pipeline project outside of the 3,000-foot section on the south side of Chino.

"There's no doubt in my mind that the last 3,000 feet was put in differently," and the rest of the pipeline compaction is better, Huza said.

Contact Joanna Dodder at jdodder@prescottaz.com and Dorine Goss at dgoss@prescottaz.com