Water Monitoring 

To meet Oregon Health Authority rules, the City of Salem monitors for the presence of Total Microcystin and Cylindrospermopsin (cyanotoxins).

Regulatory monitoring for cyanotoxins in North Santiam Watershed typically begins in April and ends in October (algae season).  Additional monitoring occurs November – April depending on the weather conditions and Detroit Reservoir water levels.

Sample Collection

Samples are collected from multiple locations at Detroit Reservoir, Big Cliff Reservoir, the North Santiam River, and the two key locations listed below:

Aldersgate

This is where treated drinking water from the Geren Island Water Treatment Facility enters Salem's drinking water distribution system on its way to homes and businesses.

Intake

This is where raw, untreated water from the North Santiam River enters the Geren Island Water Treatment Facility.

Data

Data from the Intake and from Aldersgate will be used to determine when to activate additional drinking water treatment processes at Geren Island, Thanks to an in-house ELISA testing system, the City is now able to provide Total Microcystin and Cylindrospermopsin test results faster. When toxins are detected in the North Santiam River, samples will be collected daily and the results will be available the following day on the City website.

If the need arises to issue a water advisory, a City notification will be sent through the Marion-Polk Community Alert System, posted on the front page of our website, shared with media, and posted to the City of Salem Facebook and Twitter social media accounts. The status on the City's drinking water water advisory pages will also be updated to reflect that an advisory is in effect.