Toxin Watch: Safe to Drink.

• Where: Detroit Reservoir (Log Boom), Big Cliff Dam
• Testing: Water tested seven days a week
• Treatment: Water treated by ozone, slow sand filtration, chlorine, fluoride, and soda ash
• Chlorine levels increased, then reduced to normal levels

The Oregon Health Authority developed permanent rules that require us to routinely test for cyanotoxins and notify the public about the test results. These rules have been in place since December 2018. Our monitoring and reporting procedures meet and exceed these new requirements. Prior to the new rules being in place, Oregon Health Authority used guidelines set by the U.S. Environmental Protection Agency and provided advice to the water utilities on their response to cyanotoxins.

For more about the new Oregon Health Authority rules visit their website.

To learn more about these new rules and how we are monitoring and reporting, go to our website.

Updated water quality sample test result data and news updates will be posted online as these become available.

Learn the different monitoring levels

Salem monitors conditions in the watershed all year round that could have an effect on our drinking water. Algal blooms are a natural process. In the past few years, algae can be seen in Detroit Reservoir, Salem's drinking water source, from April through October.

Here are the different water monitoring levels you could see as the water in the North Santiam River changes throughout the year. If conditions warrant a water advisory, we will let you know through the Salem Community Alert System, the status at the top of this page, and our drinking water page, posts on the homepage of our website, through local media, and posts on the City of Salem Facebook and Twitter social media accounts.

Water is safe to drink

• Routine monitoring is underway, testing is occurring weekly as there is no algae growth in the watershed. Normal treatment is in place: slow sand filtration, chlorine, fluoride and soda ash.

• Algae Watch: At this stage, water is still safe to drink. We've seen algae in Detroit Reservoir and have begun testing a minimum of two days a week. In addition to normal treatment, we've added acetic acid (a form of vinegar) to help grow the Schmutzdecke.

• Cyanotoxins Detected: At this stage, water is still safe to drink. We've detected cyanotoxins in Detroit Reservoir but, they haven't yet shown up at the intake to our water treatment plant. We will continue to test five days a week. Normal treatment is in place: slow sand filtration, chlorine, fluoride and soda ash. We may add more chlorine, and reduce it back to normal levels.

• Cyanotoxins detected. Water is still safe to drink. We have now detected cyanotoxins at the intake to our water treatment facility and have begun testing daily. In addition to normal treatment, slow-sand filters, ozone treatment, and added chlorine, we may also add powdered activated carbon to our treatment regime if needed.

Vulnerable persons advisory

• If cyanotoxin levels exceed health advisory levels for vulnerable persons, we will issue an advisory and open water distribution stations. We will continue normal treatment and added chlorine, in addition to using powdered activated carbon. The advisory may be lifted after test results show two consecutive days of sampling at concentrations below the health advisory levels.

Do-Not-drink advisory

• If cyanotoxin levels exceed health advisory levels for all people, we will issue an advisory for all people. Water distribution stations will be in place. We will continue normal treatment and added chlorine, in addition to using powdered activated carbon. The advisory may be lifted after test results show two consecutive days of sampling at concentrations below the health advisory levels.

What triggers a Do-Not-Drink advisory?

If test results show health advisory levels of cyanotoxins after treatment, the Oregon Health Authority requires a second water sample—called a confirmation sample—be taken the following day at the same location. The follow-up sample—the second part of a two-part test—is taken because health issues related to cyanotoxins are based on multiple day exposure to the toxin at concentrations above the advisory level. The results of the two-step test—initial and confirmation sample together—provide the critical information needed on the presence of cyanotoxins and how long it has been present.

Where are the samples tested?

We have our own U.S. Environmental Protection Agency-preferred water testing system, ELISA, which means test results are available sooner than if they need to be sent to another lab. If an initial result shows the presence of cyanotoxins at concentrations above the health advisory level, our staff can draw a confirmation sample as soon as possible the following day (right after midnight) and run the lab test overnight. This allows us to tell the community as soon as possible if there is a need to issue aDo-Not-Drink advisory. We post results on our website during the algal season (May 1-October 31).

What happens if cyanotoxin test results indicate the need for a Do-Not-Drink health advisory?

If cyanotoxin test results indicate the need for a Do-Not-Drink health advisory, our community and water customers will be notified through our emergency notification system, news media, and social media channels.

How will water users learn more about the potential public health issues?

We will be coordinating with the Oregon Health Authority, Marion County Environmental Services, and Oregon Department of Agriculture to provide residents and businesses the best available information on potential public health issues and steps our community can take to keep their family and pets safe. We will use the same process to let people know when our water is safe again to drink following an advisory.

The U.S. Environmental Protection Agency also has public health information on their website.

How is a Do-Not-Drink advisory lifted?

To lift a Do-Not-Drink advisory, test results must meet the Oregon Health Authority requirements of two consecutive days of sampling that show cyanotoxins at concentrations below the health advisory levels. We will also consider other factors such as cyanotoxin levels in the watershed when deciding to lift a Do-Not-Drink advisory.

What are the new rules?

The Oregon Health Authority requires us to test and to report results for two cyanotoxins produced by cyanobacteria (algae). Based on national public health research shown in the U.S. Environmental Protection Agency guidelines, the rules set two health advisory levels for cyanotoxins in drinking water—one for "vulnerable people" and one for "all persons." A health advisory level is the concentration of cyanotoxins at or below which adverse health effects are not expected to occur if consuming water containing cyanotoxins at this level for up to 10 days.

Is there a health advisory level for pets?

There is no health advisory level for pets. The U.S. Environmental Protect Agency reports cyanotoxins can be harmful to animals if they drink tap water contaminated with elevated levels of cyanotoxins. They advise pet owners to contact a veterinarian if animals show signs of illness.