Tribut= aries Big Source of River Pollution

However creeks, ditches not part of cleanup plans
By Suzanne Wentley Ft. Pierce Tribune staff wri= ter
December 13, 2002

After a year of monitoring, state scientists on Thursday said 27 of the 38 urban creeks and ditches tested in Martin and St. Lucie counties directly pollute the St. Lucie River and the southern Indian River Lagoon with high amounts of nutrients and metals.

The biweekly testing started in November 2001 to determine the quality of t= he water in the tributaries that account for 30 percent of the runoff into the river.

The tributaries are not part of the $1 billion local Everglades cleanup plan, unlike the irrigation canals in St. Lucie County and the St. Lucie Canal in Martin County. Those water= ways make up the remaining 70 percent of the flow into the river and lagoon, according to South Florida Water Management District reports.

However, Boyd Gunsalus and Al Goldstein, senior environmental scientists with the district, said the high amounts of phosphorous, ammonia, nitrites and nitrates, copper and arsenic in the area= 's small water bodies are cause for concern.

"You need to understand the problem before you can build a solution,&q= uot; Goldstein said.

"The source of the problem comes off the land," he said. "Th= ere are a lot of assumptions, that it's all citrus land, but urban is to blame too."

Goldstein and Gunsalus created an almost comprehensive list of tributaries into the local waterways, without the main irrigation canals, and contracted out the work of sampling the water for nutrients, metals and physical characteristics such as temperature, levels = of dissolved oxygen and turbidity.

Most of the creeks and ditches exceeded the levels the scientists set for phosphorous, ammonia, nitrites plus nitrates and copper.

Phosphorous and nitrites plus nitrates -- all nutrients -- can cause algae blooms, fish kills and water clarity problems in the estuary. Ammonia and copper can be toxic to marine life.

The scientists have not yet analyzed the data to determine the direct cause= of the pollutants, but Gunsalus said there are some likely sources:

Phosphorous and nitrates are often products of too much fertilizer use.

Copper could be a result of copper sulfate, an inexpensive herbicide and fungicide.

Arsenic, like the others, occurs naturally, but a high presence could be le= ft over from old cattle-dipping vats.

Ammonia can leach into groundwater from leaking septic tanks then make its = way into the waterways.

Even though state officials have yet to set maximum amounts of the nutrients and metals the river can tolerate, the scientists said they created "r= ed flag" levels at which problems can arise.

Phosphorous levels should not exceed 150 parts per billion, but 15 sites di= d. Ammonia should not exceed 100 parts per billion, but 11 did. Nitrite plus nitrates should not exceed 100 parts per billion, but 14 did.

The state Department of Environmental Protection set levels for copper: 2.9 parts per billion as a maximum for saltwater, depending on how hard the wat= er is, and 30 parts per billion maximum for freshwater.

Because the St. Lucie Estuary is brackish -- a mix of salt and fresh water = -- state scientists set the "red flag" at 6 parts per billion, and 10 sites exceeded that limit.

Gunsalus said arsenic levels were also tested. = Most sites were in the healthy range, under two parts per billion, except one tributary, Piper's Ditch, which at 5.94 parts per billion was well beyond s= tate standards.

Engineers and educators with the St. Lucie River Initiative and the Florida Yards and Neighborhoods program said the testing can help them pick the hot spots that need the most attention.

"That's the key to it all," said Edie Gastri= ght, the program assistant with Florida Yards and Neighborhoods, an educational element of the water quality improvement program administered by the agricultural extension offices.

"If you don't know where it's coming from, you don't know how to corre= ct it," she said.

Gastright said one tributary -- the Hidden River in Port St. Lucie -- will be the subject of an educational meeting on how homeowners around the waterway can stop pollution on their property. The meeting is scheduled for 7 p= .m. Monday at the Port St. Lucie Community Center.

Although the monitoring program didn't test the quantity of water flowing in the river and lagoon, Gunsalus said he planned = to add six water level stage recorders throughout the area.

Already, the water quality monitoring program costs about $160,000 a year. Water stage monitors cost about $20,000, Goldstein said.

But state scientists said it's worth it. During the next three years of the program, they will be able to gauge the effectiveness of stormwater improvements in older neighborhoods in Martin and St. Lucie counties.

"I've got a little data at Frazier Creek," Gunsalus said, referring to an early Stuart stormwater improvement project. "And it's promising."

They will also be able to examine the effectiveness of the voluntary enviro= nmental improvements at area's farms and groves, he said.

Joining all the improvement projects -- and backing them up with scientific data -- will help clean up the St. Lucie River and the Indian River Lagoon = that much faster, Goldstein said.

"They're doing things and they're doing things. Let's put it all together," he said.

- suzanne.wentley@scripps.com=