It’s the end of an era — the city of Longview officially has switched its water source to deep wells after decades of piping water from the Cowlitz River.

At 10 a.m. Thursday, Longview Mayor Don Jensen and City Councilmen Tom Hutchinson and Steve Moon turned a valve at the $33 million Mint Farm Regional Water Treatment Plant before a small crowd of city staff, contractors and Beacon Hill Water & Sewer District officials.

The council members clinked plastic cups and sipped the water pumped from the aquifer several hundred feet beneath the city-owned Mint Farm Industrial Park.

“I’d say this tastes better than what we’ve got now,” Hutchinson said.

“This is better than the old water,” remarked Moon, who’d brought along a sports bottle filled with treated river water.

Public Works Director Jeff Cameron told them to keep in mind the water must flow through the old pipes to get to their homes, which could affect the taste.

For the last couple of weeks, the city has received several complaints from citizens about the taste of the Mint Farm’s water, even though the water hadn’t been turned on yet. City Manager Bob Gregory said when he informed two callers they still were drinking river water, they were at a loss for words.

Extensive engineering studies show that surface contamination from old industrial sites does not pose a threat to the aquifer from which the new system draws water. Natural water pressure in the aquifer’s forces water up to the surface rather than down.

Water customers who live near the Mint Farm were expected to begin getting well water within an hour Thursday. The water is expected to reach customers in Longview’s hills by Friday night after it is piped to the main reservoirs before distribution to the upper zones of the system.

The water source from customer’s taps can be identified by testing for fluoride. To be able to tell the difference, the city stopped adding fluoride into the Fisher’s Lane plant on Nov. 26. Fluoride, which the city has added to its water supply for decades to fight tooth decay, will be added to the Mint Farm water when the plant is turned on. Therefore, fluoride will be the marker for Mint Farm water. City staff will regularly sample the water to track the transition of Cowlitz River water to groundwater.

The city began looking for an alternative to the Fisher’s Lane water plant in 2006 because volcanic silt in the river was damaging equipment and sediment was threatening to block the plant’s water intake. The Fisher’s Lane plant will be kept operational for several weeks after the Mint Farm plant begins supplying water to Longview utility customers, just in case there’s a big problem at the new plant.

The plant, which took two years to build, is expected to serve the city’s water capacity needs for at least 20 years before additional wells will need to be drilled, Cameron said. The city will hold a public open house at the Mint Farm treatment plant around May.

“I’m feeling great,” he said. “The plant’s working well, the water tastes great. … We’re moving on.”