Heavy metals, muck cloud Crane Creek

Further studies, safeguards needed, scientists say

BY JIM WAYMER
FLORIDA TODAY

Contaminated muck cakes the bottom of Crane Creek with mercury and silver at
50 to 100 times normal levels, putting fish and those who eat them at risk.

Recent studies by Florida Tech researchers have shown elevated levels of
those and other noxious metals that wash in with silt and clay, which also
clouds out seagrass vital to the Indian River Lagoon food chain.

The researchers say the health and environmental impacts need more study,
but the results so far raise concerns about what could be a lagoonwide
problem.

"It's a little bit of a yellow light," said John Trefry, a Florida Tech
geochemist who studied Crane Creek and several other tributaries.

Trefry and two other Florida
Tech scientists issued their final report to the St. Johns Water Management
District about clay clouding the lagoon. Similar work he and three other
Florida Tech scientists submitted to the district in 2004 turned up the
elevated mercury and other metals in Crane Creek.

The metals came from the city's past sewage discharges, upstream development
and from under boat docks, where dredges did not reach during a 1998
project.

But lagoonwide, metals from cars, power plants, paints and electronics keep
entering the estuary. They cling to clays from sod and construction sites,
flow into storm water, then ooze into the lagoon.

Specifically, the Crane Creek researchers found:

* Mercury and silver 50 to 100 times normal levels in the sediment, most
of it from 30 to 60 years ago. Trefry suspects most came from dental,
photographic and art wastes discharged when the city of Melbourne pumped
sewage directly into the creek, a practice the state banned in 1990.

* Lead up to six times above natural levels, likely from the fallout into
roadside soils when cars burned leaded gas.
* Copper two to 10 times above normal levels , most from anti-fouling
paints on boat hulls.

Mostly muck

An estimated 1,046 cubic yards of sediment flows into Crane Creek annually,
enough to fill about 62 dump trucks.

Much of that is muck -- the paste-like mix of silt, clay and decomposed
plant matter with the consistency of a rotten banana. Excess muck also can
be a sign of too many nutrients leaching from septic tanks, fertilizers and
other sources, triggering too much algae growth.

The $623,000 project in 1998 dredged about 98,000 cubic yards -- or 5,700
dump trucks worth -- from Crane Creek, pumping the spoil into three football
stadium-sized holes next to the city's water treatment plant along the
creek's southern bank.

"What we saw was that there was still a layer of muck everywhere, and that
some of it is still contaminated," Trefry said of the post-dredging study.

Preventing problems

The researchers recommended the district, along with local governments,
better control stormwater runoff with more dams, ponds and baffle boxes --
square concrete chambers linked to storm drains that capture dirt before it
enters the lagoon.

Trefry also says better enforcement on builders to control sediment on
construction sites would help.

"The science is somewhat more straightforward than the solution," he said.
"I still think we have to stop it from coming in."

A $3 million dredging project planned for late this year could do that, by
including rocks placed along the creek's banks to lessen soil erosion and a
sump in the creek to catch muck before it reaches the lagoon. The water
management district has set aside $1.3 million.

State Rep. Mitch Needelman, R-Melbourne, who lives along the creek, plans to
push this year for the additional $2 million to start the project by
October.

Carolynn and Walter Milouski notice the chronic coffee-like cloudiness in
Crane Creek.

"The water looks dark," Carolynn Milouski said as her 2-year-old, Alexander,
tossed stones into the creek one day this week at the manatee observation
area just west of U.S. 1.

They support dredging Crane Creek and other lagoon tributaries, as long as
it cleanses the lagoon enough to foster more marine life. The Palm Bay
couple likes to bring their son to see the manatees, catfish and the turtles
that loiter in Crane Creek just east of the railway bridge -- most days,
that is.

"Not even a catfish today," Walter Milouski said.

Fair Use Disclaimer

The Pelican Island Audubon Society web site, www.pelicanislandaudubon.org, is a nonprofit, noncommercial web site that, at times, may contain Copyrighted material that have not always been specifically authorized by the Copyright owner. The Society makes such material available in its efforts to advance the understanding of issues related to Florida’s natural environment in hopes of helping to find solutions for those problems. It believes that this constitutes a “fair use” of any such Copyrighted material as provided for in Section 107 of the US Copyright Law. Persons wishing to use Copyrighted material from this site for purposes of their own that go beyond “fair use” must first obtain permission from the copyright owner.

All articles are copyrighted by the respective newspapers.