According to information provided by the Association of California Water Agencies, the legal decision signifies TID was still required to obtain a NPDES permit though the herbicide Magnacide H was applied as directed by the U.S. Environmental Protection Agency-approved label.
Left untreated, weeds and algae clog waterways, diminish their capacity and efficiency and leave unpleasant flavors and odors in drinking water.
The decision, which affects California and other western states, also establishes irrigation canal tributaries to waters of the United States can be subject to federal Clean Water Act regulations. Failure to comply with Clean Water Act regulations can result in civil and criminal penalties.
According to ACWA, the decision apparently applies to all registered aquatic pesticides including herbicides, algaecides, fungicides and insecticides regardless of application in compliance to the product label.
The decision, however, raises more questions than it offers solutions.
"Unfortunately, it leaves districts like the IID totally in limbo," said Elston Grubaugh, IID principal engineer.
IID uses the herbicides Rodeo and Roundup on its canal banks but does not put those herbicides directly into canal water, Grubaugh said.
The court decision doesn't make it clear if such canal bank application is covered by the ruling, Grubaugh said.
IID has not stopped spraying its banks with the herbicides, Grubaugh said.
Guidance from the state hasn't been forthcoming, although there have been indications in Northern California that a permit will be needed, Grubaugh said.
According to ACWA, the EPA has delegated its Clean Water Act authority in California to the State Water Resources and Regional Water Quality control boards.
ACWA officials say those two agencies do not have the administrative capability to issue NPDES permits for aquatic pesticide applications and that such a permit could take as long as two years to develop and adopt.
"If we lose the ability to use these chemicals, we lose the ability to treat waterways," Grubaugh said.
Without treatment, delivering water will be problematic, Grubaugh said.
Staff Writer Kelly Grant can be reached at 337-3441.