CAS No. 27314-13-2
Pesticides appearing in Caloosahatchee samples
By Eric Staats. Naples Daily News. April 11, 2005.

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Naples Daily News (Florida)

April 11, 2005

Pesticides appearing in Caloosahatchee samples


Pesticides are showing up in water samples from the Caloosahatchee River, raising concern among river watchdogs and prompting talk of a closer look by state regulators.

Quarterly monitoring by the South Florida Water Management District at three spots along the river has found various pesticides, in some cases at levels that two local watchdog groups say are high enough to harm small marine life.

The Conservancy of Southwest Florida and the Southwest Florida Watershed Council made monitoring results since 1998 the focus of letters to the state Department of Environmental Protection in 2004.

The groups urged the DEP to look more closely at listing the Caloosahatchee River as impaired under the Clean Water Act because of the pesticide levels, a step that would trigger clean-up requirements. The river already is listed on a draft list as impaired for malathion.

In a February letter to the Conservancy, DEP program administrator Daryll Joyner wrote that the agency disagreed that pesticides were at high enough levels or found often enough in the river to warrant a spot on the list.

Joyner wrote that the DEP wants to "further study this potential problem" with local stakeholders and will work with the state

Department of Agriculture and Consumer Services to determine whether new rules are needed for how pesticides are used in the river's watershed.

Conservancy policy manager Matt Bixler said the group is encouraged by those pledges for more study but hasn't given up on getting the Caloosahatchee River listed as impaired for additional pesticides.

"Address the problem is what we're looking to do," Bixler said.

Chemicals found in the river's water comprise weed killers and insect killers that are used at citrus groves, vegetable farms, sugarcane fields and, in some cases, on yards.

The Water Management District's monitoring stations on the river are near Olga in eastern Lee County, on the Lee-Hendry county line and in Glades County.

The Caloosahatchee River runs past groves and farms in Hendry, Glades and Lee counties, and the river takes water from Lake Okeechobee, where water from sugarcane fields south of the lake is pumped.

In their letters, the Conservancy and the Watershed Council cite tests that have detected atrazine, bromacil, metolachlor, norflurazon and simazine.

The pesticides have been found at levels that are fractions of micrograms per liter, a unit of measurement often referred to as parts per billion — where one part per billion is equivalent to one second out of 32 years.

The letters also refer to a 1998 sample that found ethoprop in the river's water and refers to one sample in 2000 and four samples in 2003 that found diazinon.

Ethoprop and diazinon were found at levels that exceed what scientists call acute and chronic toxicity levels, according to the groups.
Florida water quality standards say a pesticide is at chronic toxicity levels if it is at one-twentieth of the amount that tests have found to be lethal to 50 percent of test organisms in 96 hours. Acute toxicity is one-third of that level, according to state standards.

The 1998 sample found ethoprop at acute toxicity levels for a type of shrimp and chronically toxic to bluegill, according to the Conservancy's review of toxicity levels reported in the Hazardous Substance Data Bank.

The Conservancy review showed that the 2000 and 2003 samples found diazinon at chronic toxicity levels for a tiny crustacean, commonly called a water flea, that is important to the food chain.

In the DEP letter, Joyner wrote that DEP biologists' review of an EPA database found nothing to indicate that the pesticide levels in the Caloosahatchee River were toxic, with the "possible exception" of the diazinon data.

Joyner refers to debate over the use of toxicity testing and points out that toxicity testing is seldom done to measure pesticides in rivers.
The DEP uses toxicity testing to measure effluent coming into a body of water from a discharge point, Joyner wrote.

Judy Sanchez, a spokeswoman for Clewiston-based U.S. Sugar Corp., said she had no comment on whether pesticides used in sugarcane fields is a problem in the Caloosahatchee River.

"It seems like if DEP is looking at that data, they're a better person to speak to that than we are," Sanchez said.

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