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. Samples are collected from multiple locations at Detroit Reservoir, Big Cliff Reservoir, the North Santiam River, and the two key locations listed below:
- Intake – this is where water from the North Santiam River enter s the Geren Island Water Treatment Facility.
- Aldersgate – this is the point where treated drinking water from Geren Island enters Salem's drinking water distribution system.
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.