BFHD Harmful Algae Bloom Season Recap

Left Image Below: Planktonic algae growth suspended in the water column, usually within a few feet of the surface. Often times has a "pea soup" appearance with cloudy water giving an obvious indication of a bloom to even the untrained eye.

Right Image Below: Benthic types of algae grow on the bottom of a water body, attaching themselves to sediment or structures, such as rocks. The algae grow on the surface of these structures near the shoreline and the water in these areas remains relatively clear. The layers of growth on these structures are called "mats", if conditions, like water temperature and water level changes significantly, then the mats can break loose and travel downstream. 

The algae in the Columbia River are primarily benthic.

During early fall of 2021, portions of the shores of the Columbia River that flow through the Tri-Cities area (Richland, Kennewick and Pasco) were closed after the deaths of several dogs who had been exposed to toxic algae while along the shoreline. 

Benton-Franklin Health District was aware of this issue occurring in local lakes and rivers. What made this incident in 2021 unique was that toxin-producing blooms had not been found in the flowing waters of the Columbia River. Of concern was that the area in which the blooms appeared to be occurring was the same area where the cities of Richland, Kennewick and Pasco have water intakes for their drinking water treatment facilities. BFHD works closely with these utilities to make sure that the drinking water is safe.

In 2022, Benton-Franklin Health District worked with partners to improve lab capacity to allow for ELISA screening. ELISA can perform preliminary screening for anatoxin-a or microcystin in house. Samples that screen above .2ug/L get sent to King County Environmental Lab for further analysis with LC/MS. This pre-screening process provides an up-to-date picture of the toxin levels in our waters, while minimizing what gets sent to King County Environmental Lab.

Interlocal sampling agreements were established with four cities, allowing for both routine sampling of both recreational and drinking water locations. With the addition of Foundational Public Health Services funding BFHD hired a full time Climate Specialist.

To kick off the 2023 HAB season, the Climate Specialist negotiated and extended the interlocal sampling agreement to five years with four cities. A comprehensive sampling program SOP was created, along with a REDCap database and standardized field collection forms. The Climate Specialist provided training, oversite, and coordination of six sampling sites bi-weekly from April through November 2023.

Laboratory analysis of samples from twelve sites (6 drinking water, 6 recreational) were performed bi-weekly in house by BFHD Laboratory staff and the Climate Specialist. The Climate Specialist managed data collection and communication of results to municipal partners.

In 2023, the Climate Specialist partnered with various local and federal agencies, including EPA and USGS. BFHD staff met with EPA officials on several occasions to discuss their sampling methods and current work along the Columbia River. EPA is conducting an intensive study along the Columbia River shoreline in north Richland to determine the types of algae present & what toxins are being produced. In mid-September, the Climate Specialist went out with EPA staff to assist and observe their work with benthic algae. Their work will guide how BFHD conducts sampling events in the future.

USGS is using technology to monitor physical parameters that may be influencing the growth and distribution of the algae in the Columbia River. The sensor is measuring parameters such as water temperature, dissolve oxygen, turbidity, flow rate, and photosynthetic pigments that are often associated with cyanobacteria.   The goal of this project is to use this data to make predictions about when algae growth will be at its worse. BFHD has been assisting USGS with the selection of more sensor sites on the Columbia and helping them to maintain sensors already in place.