SACRAMENTO – The Central Valley Regional Water Quality Control Board is urging boaters and recreational users to avoid direct contact with or use of waters containing blue-green algae, or cyanobacteria, in the Mountain Meadows Reservoir in Lassen County.

The recommendation is based on the potential health risks from the algae, which is currently blooming in the reservoir.

Central Valley Regional Water Quality Control Board staff visually observed a cyanobacteria bloom in the reservoir near the Indian Ole Dam. 

Bloom conditions can change rapidly and wind and waves may move or concentrate the bloom into different regions of the reservoir. 

A water sample collected near the dam has confirmed the presence of at least two different cyanobacteria genera (Gloeotrichia sp., and Aphanizomenon sp.). 

These types of cyanobacteria are capable of producing toxins.  However, the presence of toxins has not been confirmed.

Mountain Meadows Reservoir is a recreational lake near the town of Westwood and is part of the Upper Feather River Hydroelectric System operated by Pacific Gas and Electric Co. The lake is not used for drinking water supply.

PG&E has posted caution signs at known public access points around the reservoir and along Hamilton Branch, where water discharges from the Indian Ole dam.   

Blue-green algae can pose health risks, particularly to children and pets. People are urged to choose safe activities when visiting Mountain Meadows Reservoir and recommend that people and their pets avoid contact with water, and avoid swallowing lake water in an algae bloom area.

This map  indicates the location in Mountain Meadows Reservoir where a cyanobacteria bloom was visually confirmed (Indian Ole Dam): https://us.vocuspr.com/Publish/3240560/vcsPRAsset_3240560_63705_49ace0e8-9b68-4a37-bcbf-db4f5cb0ead1_0.png .

An evaluation of a water sample collected near the Indian Ole Dam has confirmed the presence of at least two different genera of cyanobacteria – Gloeotrichia sp. and Aphanizomenon sp.

The algae bloom can appear as cut grass in the water or blue-green, white or brown foam, scum or mats that can float on the water’s surface and accumulate along the shoreline and boat ramp area.

Recreational exposure to toxic blue-green algae can cause eye irritation, allergic skin rash, mouth ulcers, vomiting, diarrhea, and cold and flu-like symptoms. Pets can be especially susceptible because they tend to drink while in the water and lick their fur after.

The Statewide Guidance on Cyanobacteria and Harmful Algal Blooms recommends the following for blue-green algae impacted waters:

– Take care that pets and livestock do not drink the water, swim through algae, scums or mats, or lick their fur after going in the water. Rinse pets in clean water to remove algae from fur.
– Avoid wading, swimming, or jet or water skiing in water containing algae blooms or scums or mats.
– Do not drink, cook or wash dishes with untreated surface water from these areas under any circumstances; common water purification techniques (e.g., camping filters, tablets and boiling) do not remove toxins.
– People should not eat mussels or other bivalves collected from these areas. Limit or avoid eating fish from these areas; if fish are consumed, remove guts and liver, and rinse filets in clean drinking water.
– Get medical treatment immediately if you think that you, your pet, or livestock might have been poisoned by blue-green algae toxins. Be sure to alert the medical professional to the possible contact with blue-green algae.

For more information visit the following:

– California Department of Public Health: http://www.cdph.ca.gov/healthinfo/environhealth/water/Pages/Bluegreenalgae.aspx ;

– State Water Resources Control Board - California CyanoHAB Network: http://www.mywaterquality.ca.gov/monitoring_council/cyanohab_network/index.html ;

– California Office of Environmental Health Hazard Assessment, information on microcystin: http://oehha.ca.gov/ecotoxicology/general-info/information-microcystins ;

– US Environmental Protection Agency CyanoHAB Web site: https://www.epa.gov/nutrient-policy-data/cyanohabs ;

– US Environmental Protection Agency, Anatoxin-a report: https://www.epa.gov/sites/production/files/2015-06/documents/anatoxin-a-report-2015.pdf .