Sweet Home water tests clear of cyanotoxins

Sean C. Morgan

Testing has showed Sweet Home’s drinking water is clear of the cyanotoxins detected in May in Salem’s drinking water supply.

Public Works Director Greg Springman and Jacobs Project Manager Steven Haney reported the findings to the City Council during its regular meeting on July 10.

Springman told the council the city had received the test results for the city’s treated water that day. The city sampled finished drinking water on June 14. That test generally takes up to two weeks to complete.

The city also sampled its raw water, which is drawn directly from Foster Reservoir, on June 25. That test also failed to detect cyanotoxins.

Downstream along the South Santiam River, tests have not detected cyanotoxins in Albany’s water supply.

In May, Salem detected cyanotoxins in its drinking water, which originates in the North Santiam River and Detroit Reservoir. Emergency officials sent out alerts, which also reached Sweet Home residents, to warn against drinking the water.

Since then, the Oregon Health Authority created a temporary rule requiring other Oregon cities that use surface water for drinking to test for cyanotoxins every two weeks through Oct. 31. Sweet Home began testing prior to implementation of the rule this month. The state has agreed to pick up the lab costs.

Springman expects the OHA to implement a similar permanent rule that will require ongoing testing throughout the summer.

Cyanobacteria may produce toxins that pose a risk to the public, Springman said, with children under the age of 6, the elderly, people with immune problems, pregnant women and pets most at risk.

That bacteria can flourish in an algae bloom, like the algae blooms in Detroit that apparently led to the detection of cyanotoxins in Salem’s drinking water supply.

If a bloom occurs, it doesn’t automatically mean the toxin is produced, Springman said, but it increases the risk of toxins.

Normal treatment cannot remove the cyanotoxins, he said. It can be removed, but “our system can’t.”

“We’re in a better situation (than others), but there’s still that risk,” Springman said. City officials have been discussing monitoring and preparedness.

Should that need arise, Brownsville has agreed to provide bulk water, and No Drought has four trucks it can use to transport water, Springman said. Officials also have looked into cost of setting up a clean water source behind the new City Hall, where people could bring their own containers to fill.

Springman said Sweet Home is in a pretty good position compared to Salem, which uses a different filtration system and stores its water in ponds for longer periods of time during the treatment process. Temperature is a big part of algae growth, and Sweet Home pulls water from a minimum of nearly 14 feet below the surface of Foster Lake, where the temperature is lower.

Sweet Home draws water from the 600-foot mark, while the surface of Foster Lake typically runs above 613 feet above sea level during the winter. During the summer, it is normally kept at more than 635 feet, more than 35 feet above the intake pipe.

Salem had a “perfect storm” when it experienced cyanotoxins, Haney said. Detroit Reservoir was full for the first time in a decade, and the Corps of Engineers was running warmer algae-laden surface water over the top of Detroit Dam instead of through the dam’s turbines.

But Sweet Home is vulnerable, Springman said. “We need to start thinking at least strategically how to deal with that.”

Haney said his company, Jacobs, is looking into techniques for treatment, including activated carbon, ozone and a membrane system.

For more information about cyanotoxins and algae, visit the OHA website at http://www.oregon.gov/oha/PH/HealthyEnvironments/DrinkingWater/Operations/Treatment/Pages/algae.aspx.

Present during the meeting were councilors Bob Briana, Susan Coleman, Lisa Gourley, Mayor Greg Mahler, Dave Trask, James Goble and Diane Gerson.

In other business, the council held the first and second readings of a proposed ordinance to regulate accessory dwelling structures, which are now allowed by state law for each primary dwelling unit on a property.