Zone 7 explains hard water Zone 7 explains hard water (January 16, 2004)

More groundwater used while facilities under repair

The tap water has been hard lately, reported Zone 7 water agency, because it is adding more groundwater than usual to the Delta water used in Pleasanton while doing seasonal maintenance on its facilities.

"We try our best to keep these periods short to minimize any inconvenience to our customers," said Dale Myers, Zone 7 general manager.

The water has been harder than usual lately in Pleasanton, Dublin and Livermore, and residents may have noticed a stronger mineral taste. The water also may leave spots or cloudy residue on dishes, cars and clothes.

Normally groundwater makes up about 25 percent of the treated water delivered to these cities. But due to the maintenance in recent weeks to the facilities that treat surface water imported from the Sacramento-San Joaquin Delta, Zone 7 has increased the proportion of groundwater to surface water to as much as 100 percent groundwater in some areas. Zone 7 hopes to return to normal in March.

Groundwater in the Tri-Valley is naturally hard, particularly in the Pleasanton and Dublin areas, according to Zone 7, due to minerals such as calcium and magnesium. But the groundwater does surpass state and federal safety standards for drinking.

Zone 7 is working on ways to improve the hard water, such as wellhead demineralization. It also has projects to increase the availability of surface water for blending, such as the South Bay Aqueduct Improvement and Expansion Project and the future Altamont Treatment Plant.

To receive more information about tap water, call the city of Pleasanton at 931-5510. -Dolores Fox Ciardelli

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