Naples Daily News (Florida)
April 11, 2005
Pesticides appearing in Caloosahatchee
By ERIC STAATS, firstname.lastname@example.org
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
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
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,"
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
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
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.
Copyright 2005, Naples Daily News. All Rights Reserved.