Water Quality

Water Quality

Monitoring and Testing for Blue Green Algae Cyanotoxins in the Clackamas

Cyanobacteria, sometimes called blue-green algae, are microscopic organisms found naturally in all types of water; fresh, brackish (combined salt and fresh water), and marine water. These organisms use sunlight to make their own food. When present in large numbers they may form visible green, blue-green or reddish-brown blooms that float on the surface of the water.

Not all blue-green algae blooms produce toxins, but under certain conditions, such as in warm water containing an abundance of nutrients, they can rapidly form harmful algal blooms (HABs) capable of producing toxins known as cyanotoxins that can harm humans and animals.

How is the drinking water utility protecting me, my family and our pets from the risk of cyanotoxins in our drinking water?

The Clackamas River Water Providers have been working with PGE since 2006 to monitor for blue green algal blooms in the Clackamas River. Through these efforts PGE conducts weekly monitoring for blooms at North Fork Reservoir from May to October each year. If a blue green algae bloom is identified by PGE, samples are taken and tested for toxins.  

Our drinking water treatment systems on the Clackamas River can remove the risks to humans and pets from drinking water with cyanotoxins in all conditions except those that may occur during an extremely large and long duration cyanobacteria bloom.  It is only the blooms that are very large and last a long time that create a risk from drinking the water, because under all other conditions our treatment processes, which are designed to meet all Federal and State Drinking Water health protection mandates, provide multiple layers of protection.

To date no toxins have ever been detected in finished drinking water from the Clackamas.  If toxins ever were found in finished water the public will receive public notification with additional information.

We will continue to work closely with PGE to monitor for blooms throughout the summer months.

Clackamas Subbasin TMDL

Clackamas River has very good water quality, however, analysis of temperature and bacteria data have indicated that parts of the Clackamas River do not meet state water quality standards at all times. Four stream segments are listed on the 2002 Oregon 303(d) list for temperature and eight stream segments also violate the E. coli bacteria criteria for water quality due to excessive concentrations of fecal bacteria. These bacteria are produced in the gastrointestinal tracks of warm-blooded vertebrate animals, and indicate the presence of pathogens that cause illness in humans.  

The water bodies that violate the temperature standard are: the Clackamas River from its mouth to River Mill dam, Eagle Creek from its mouth to the wilderness boundary, Fish Creek and Cow Creek. Water that is consistently over 64 degrees can foster algal blooms that decrease water quality and impart an unpleasant taste and odor into drinking water. It can also be detrimental to Salmon and steelhead. For more information about DEQ ‘s Water Quality Standards or for an overview of the Clackamas Subbasin TMDL click here.

In 2002, the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) implemented Source Water-Quality Assessments (SWQAs) to characterize the quality of selected rivers and aquifers used as a source of supply to community water systems in the United States. These assessments are intended to complement drinking-water monitoring required by Federal, State, and local programs, which focus primarily on post-treatment compliance monitoring.

The long-term goal of this program is to complete SWQAs at about 30 systems that withdraw water from streams by 2012 using standard protocols and nationally consistent methods. The Clackamas River was one of the first nine community water systems sampled as a part of this program. The USGS has prepared a Fact Sheet called Organic Compounds in Clackamas River Water Used for Public Supply near Portland, Oregon, 2003-05 as part of the National Water-Quality Assessment Program, Source Water-Quality Assessment for the Clackamas River data. Click here for a pdf of the fact sheet.

The Clackamas River Water Providers are implementing a number of on going water quality programs which include and streamflow monitoring, and funding for maintenance and upkeep of the water quality monitoring stations.  In addition the CRWP has developed a Drinking Water Protection Plan that will help guide our efforts our source water protection efforts for years to come.

Monitoring Contract with USGS

The Clackamas River Water Providers, have a Joint Funding Agreement with USGS for the operation and maintenance for three water quality monitoring stations at Carter Bridge, River Mill, and Oregon City on the Clackamas River. These monitoring stations continuously log pH, conductivity, dissolved oxygen, turbidity, and temperature. The River Mill and Oregon City sites also record chlorophyll and streamflow. In addition to USGS contract the CRWP also provide funding for replacement probes and cables, and for the utility fees for the real time data signal associated with the USGS monitoring sites. The water quality data can be accessed via the web at https://or.water.usgs.gov/clackamas/monitors/.

Source Water Sampling

Since the early 2000’s the water providers have been taking monthly samples through out the Clackamas River Watershed to monitor changes in the watershed and and water quality.