Lake Davis Fisheries Management

Rotenone and CFT Legumine
Information Sheet
Lake Davis Pike Eradication Project
September 2007

Rotenone is a naturally occurring compound that is derived from the roots of a tropical plant of the bean family. Rotenone compounds have been used by people worldwide for centuries to stun and kill fish for food.  CFT Legumine is a commercially available formulation of rotenone.

Several laboratory analyses have been done on CFT Legumine, including the seven lots (manufacturing batches) that will be used in Lake Davis.  Although CFT Legumine is approved for use by both the U.S. Environmental Protection Agency and the California Department of Pesticide Regulation, we have done this analysis to address the public’s concerns and desire to know what chemicals are being used on the project, including any inert ingredients.

Ingredients

The active ingredient of CFT Legumine is rotenone, which is 5% of the formulation.  The other main ingredients, as described on the label and determined in the lab are:   methyl pyrrolidone, diethylene glycol monoethyl ether, fatty acid esters, and polyethylene glycols.  These compounds are used to help the rotenone mix with water.  A number of trace compounds have also been detected, including naphthalene, substituted benzenes and hexanol.

Rate of application

In Lake Davis, the CFT Legumine will be applied at a rate of about one part per million.   The rotenone itself will initially be present at a rate of about 50 parts per billion.  The trace compounds will be present at a few parts per billion at the greatest, and many will not be detectable in the water when the rotenone is applied.

What is a part per billion?

A part per billion means one part of a substance to a billion parts of water, or “one billionth.”   For example, one part per billion of Interstate 80 between New York and San Francisco (about 3000 miles) is less than ¼ inch.

Even if they are found in small quantities, could the compounds persist or build up in the food chain?

None of the compounds identified are considered persistent in the environment nor will they bioaccumulate.  They are rapidly biodegraded, hydrolyzed and/or degraded  by sunlight.

More information

More detail can be found on the specific ingredients and trace compounds, the concentrations at which they will initially be present in Lake Davis, their toxicity, and behavior in the environment in Chapter 14 (PDF) and Appendix J (PDF) of the EIR/EIS, and in the Screening Level Risk Analysis of Additional Constituents.