SAN FRANCISCO (CBS / AP) – A judge has tentatively agreed to have customers pay a little more than half the $2.2 billion cost to improve Pacific Gas & Electric Co.’s gas lines.

But the judge rejected the utility’s request to have ratepayers shoulder 84 percent of required safety upgrades to their pipelines.

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The California Public Utilities Commission judge’s proposed decision Friday to have ratepayers pay roughly 55 percent of the overall cost is aimed at improving record-keeping and safety testing of PG&E’s gas transmission lines.

KCBS’ Mark Seelig Reports:

The deadly San Bruno explosion prompted the improvement plan. The September 2010 blast killed eight people and destroyed 38 homes.

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Last year, the commission required state utilities to forecast how they would pressure-test or replace the untested segments of their gas transmission lines.

Consumer advocates expressed disappointment at the tentative decision handed down Friday. Public comment was extended through mid-November.

A final decision is expected in late December.

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