Lake Herman water substituted for Lake Berryessa supply, though some residents complain about quality

Damage to the 24-inch pipeline that carries untreated water from Lake Berryessa to the Benicia Water Treatment Plant is being repaired, city water officials said Wednesday.

Until the repairs are complete, Benicia is taking advantage of “free rainfall” that fell on Lake Herman in December and is treating and distributing water from that source, said Public Works Director Graham Wadsworth and Scott Rovanpera, water treatment plant superintendent, in a joint statement.

The South Napa Earthquake Aug. 24, 2014, caused cracks in the pipeline that begins at the end of the Putah South Canal in Cordelia. Benicia city employees discovered the damage Dec. 1 after the pipeline was brought into service Nov. 15.

The city is more dependent on Lake Berryessa water since the State Water Project (SWP) dramatically reduced how much Benicia would get from its SWP contract for North Bay Aqueduct water.

Normally, Benicia counts on the SWP contract for Sacramento-San Joaquin Delta water for 75 to 85 percent of its supply, and uses about 10,000 acre-feet, or 3.3 billion gallons, of water annually. That changed when the state decided last year its contractors would get no more than 5 percent of their contracts.

The city gets 15 to 25 percent from Lake Berryessa, and its third major water source is Lake Herman, which supplies raw water to Valero Benicia Refinery and is the city’s emergency water supply.

A section of the Berryessa pipe that runs underneath Interstate 80 in Fairfield is suspended on pipeline insulators within a 36-inch steel casing, Wadsworth and Rovanpera said.

Though the pipe was five miles from the earthquake epicenter, the ground movement caused the pipe to compress and recoil within the casing, damaging three pipe joints, they said.

For nearly a month, construction crews excavated the pipeline, videotaped the interior and repaired cracks in three welded pipe joints, the two said.

When December storms increased natural organic concentration in the North Bay Aqueduct, that water became more expensive to treat, and that reduced water quality, Wadsworth and Rovanpera said.

However, that rain caused Lake Herman to reach its overflow point, the two said.

“In the interest of using ‘free rainfall,’ the Water Treatment Plant staff switched to the Lake Herman source,” they said in their statement. That change took place Dec. 18.

Though they said Lake Herman water meets all federal and state standards for primary drinking water quality and “is perfectly safe to drink,” some residents have heard for years that fish caught there shouldn’t be eaten, and those who come here to fish often are given that advice.

Among those who had heard residents question the lake’s quality is Carolyn Wynn, who said she also noticed a change in her water quality about Christmas time, particularly when she washed her hair.

“It felt like I put conditioner in my hair when I didn’t,” she said. Her hair wasn’t as tangled and was soft. She didn’t see any difference in her laundry.

But she has noticed that her skin feels like she never gets all the soap off after she washes.

“It felt slimy. And my hair was flat,” she said. She has the same impression when she washes dishes by hand using the new water, which she said she does to save water.

She said she mentioned her experiences to friends, and they said they also noticed a change.

Wynn said she called City Hall and was told about the switch to Lake Herman water and changes in water treatment procedures to accommodate the switch.

“They were very up front,” she said. However, she said city employees should notify water customers of such changes before they happen, particularly should customers have sensitivities.

She, too, said she had heard recommendations not to eat fish caught in Lake Herman, and rumors of mercury contamination. “But that could be an old wives’ tale,” she said. Regardless, she’s decided to drink bottled water until the city starts sending Lake Berryessa water through its pipes.

Though Lake Herman’s water is treated differently than that from other sources, both Wadsworth and Rovanpera insisted the water has no mercury contamination. Valero Public Affairs Manager Sue Fisher Jones referred Lake Herman water quality questions to Wadsworth, saying refinery operations specifications for treatment of raw water differ from requirements for treated potable water delivered to other Benicia customers.

“The Lake Herman source meets all federal and state standards for primary drinking water quality and is perfectly safe to drink,” Wadsworth and Rovanpera said. “Lake Herman water quality is free of mercury contamination, as has been demonstrated in the past five years of sampling.”

City Manager Brad Kilger added, “The city can assure the citizens the water is safe.”

Water customers may have noticed “a slight change in flavor and possibly aroma due to the algal concentration in the lake,” Wadsworth and Rovanpera said. But cooler weather and reduced sunlight this time of year stunts that growth, they said.

“The Water Treatment Plant has not received any water quality complaints during the switch over to Lake Herman water,” they said in their statement. “Because of this decision, the city was able to treat over 400 acre-feet of rainfall that was captured in Lake Herman during the December storm, thus conserving our North Bay Aqueduct supply.”

Those conservation efforts are needed as complementary to imposed water restrictions, voluntary consumption reductions and other efforts Benicia as a municipality and community are taking to cope with the severe drought and the dramatic slashing of the SWP allocation.

Wadsworth and Rovanpera said Water Treatment Plant employees have been monitoring the water quality of the North Bay Aqueduct weekly this month.

But once the 24-inch Cordelia Transmission Main is put back into service — they would not speculate on when that will be — Benicia will switch back to Lake Berryessa water, they said.

Cost of the repairs has reached $105,000, the two said, but Benicia has asked the Federal Emergency Management Agency for reimbursement.

Wadsworth and Rovanpera said, “It is likely that the city will be reimbursed for 93 percent of the $105,000 repair cost.”