Water from underground flows to county's taps

Sealed systems less vulnerable to contamination than Portland's

By Eric Florip, Columbian transportation & environment reporter



By the numbers

• 200,000: The approximate number of customers served by the city of Vancouver’s drinking-water system.

• 11: Water stations included in the system.

• 3: Underground aquifers the city draws from.

• 1,026: Miles of pipes used to deliver water.

photoWorkers from HCI Industrial & Marine Coatings, Inc., put up scaffolding around the city of Vancouver's Water Tower 7. Crews will repaint the 115-foot-tall water tower this year, in part to prevent corrosion and extend its life. The steel tower is one of 11 enclosed water stations in the city that draw drinking water from underground aquifers. The $633,569 repainting project is expected to be completed by this fall.

(/The Columbian)

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When the city of Portland sent word of a bacterial contamination in its drinking water supply over the weekend, Vancouver's public works department took notice.

Not because Vancouver was affected by the incident — in fact, the two cities draw from separate and very different water supplies. Rather, local officials wanted to keep tabs on their neighbor's health risk and the response that followed.

"We always watch, regardless of where it is," said Loretta Callahan, a Vancouver public works spokeswoman. "I think it's always good to be aware of what's happening."

Vancouver's water supply isn't likely to see the same type of contamination that affected an estimated 105,000 Portland customers on Saturday and Sunday. The difference: Vancouver draws its drinking water entirely from underground aquifers. Portland uses above-ground sources, sent through a system that includes five uncovered reservoirs in the city. That leaves its water supply more susceptible to outside contaminants — in the most recent case, likely animal or human waste, according to the Portland Water Bureau.

A sample collected from one of Portland's open-air reservoirs in Washington Park showed possible bacterial contamination last Thursday. When the results of a follow-up test were confirmed Saturday, the city told its west-side customers to boil their tap water before using it. The order was lifted Sunday morning.

It wasn't the first time the city has confronted contamination in its drinking water. Routine cleaning of other Portland reservoirs has revealed such unseemly treasures as bags of dog waste in the past, said Tim Hall, public information manager with the Portland Water Bureau.

Vancouver draws drinking water from three main underground aquifers, sent through 11 well stations -- towers are above ground, but contained — to some 200,000 customers. The system is completely closed, Callahan said, "from the ground to the tap."

Vancouver hasn't issued a boil-water order in recent memory, Callahan said. But city officials have a plan in place to get the word out quickly in the event of contamination. That includes announcements through the Web, local media, social media and the Clark Regional Emergency Services Agency. And that's a big reason the city watches what works — and what doesn't — in other cities' responses, Callahan said.

Clark Public Utilities, which provides water to about 30,000 customers in Clark County, uses a system similar to Vancouver's. The utility draws drinking water from underground aquifers through dozens of groundwater wells. Most of those are in the Salmon Creek watershed.

Risks to underground water sources stem more from the metals and minerals around them, said Clark Public Utilities spokeswoman Erica Erland. Both the utility and the city add chlorine to their water as a precaution against contamination. Vancouver has also added fluoride since the city council approved the practice in the 1960s.

Neither Erland nor Callahan reported hearing of any customers' calling because of Portland's weekend notice. If such an event happened here, officials wouldn't waste time getting the word out, Callahan said.

"Water is such a critical part of our lives, and it's important that we be able to reach people," she said.

Eric Florip: 360-735-4541; http://twitter.com/col_enviro; eric.florip@columbian.com.