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Chandler explosion: Southwest Gas previously proposed enhanced pipe inspections

Chandler explosion
Posted at 10:01 PM, Sep 08, 2021
and last updated 2021-09-09 07:45:33-04

CHANDLER, AZ — State utility regulators denied a proposal by Southwest Gas to step up Driscopipe 8000 pipe inspections and replacements less than a year before a Chandler explosion involving the same kind of pipe.

Four men were seriously injured in the Aug. 26 blast at Platinum Printing in a strip mall on the corner of Ray and Rural roads. ATF investigators and Chandler police determined the explosion was accidental.

On Wednesday, Southwest Gas announced the results of its initial investigation. The company said a leak in a Driscopipe 8000 line led to the explosion. Federal regulators had warned in 2012 that this type of pipe can prematurely deteriorate in the Desert Southwest.

After a 2014 garage explosion, Southwest Gas had done some remediation to lines it determined to be most prone to leaks. The company said the “stub” pipe near the Chandler site would have been part of that plan if it had not been mislabeled as a different time of pipe in construction records.

Southwest Gas has approximately 10,800 miles of Driscopipe 7000 and 8000, and at least 129 leaks have been detected in degraded pipes as of March 2019, according to a search of Arizona Corporation Commission records. The commission regulates public utilities in the state.

In its 2019 rate increase request, Southwest Gas requested a monthly customer surcharge to pay for a more extensive search for the faulty pipes. In past years, the company would only inspect pipes if leaks were detected or if they were excavated for other purposes.

The proposed enhanced field inspections would have included additional actions such as performing investigatory dig and inspect activities to identify external material degradation. The company said it could proactively assess more of this pipe with additional funding.

"It is prudent to replace pipe that is not performing as expected before the pipe leaks, resulting in a safety concern,” Southwest Gas claimed in its request.

When the Arizona Corporation Commission issued its decision in the rate case, it denied Southwest Gas’ request for the surcharge and pipeline program.

"Based on staffs engineering analysis, the company's leak performance records do not support the accelerated replacement of the 7000/8000 Driscopipe," the December 2020 decision said. "The evidence does not establish the existence of an immediate public health and safety concern."

The ABC15 Investigators emailed corporation commissioners asking whether regretted the decision after seeing the damaging effects of a leaking Driscopipe 8000 in Chandler.

Commissioner Sandra Kennedy responded in a written statement. She said the commission expects the company to make necessary repairs even without an approved program.

“As a public service corporation, the company is obligated to maintain its facilities in a manner which protects public health and safety,“ Kennedy wrote.

The commissioners agreed unanimously to call on Southwest Gas to answer questions in a public meeting about the Chandler incident.

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