Polluted Lake (Okeechobee) Muck Causes Concern

Flipper

Flipper

Well-Known Member
Sorry, hab's grad mal kopiert

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Polluted Lake Muck Causes Concern

By Associated Press
Posted July 8 2007, 7:57 PM EDT



[FONT=Verdana,Arial, Helvetica]FORT LAUDERDALE, Fla. -- Scientists have found elevated levels of arsenic and other pesticides in thousands of truckloads of muck scooped from the bottom of Lake Okeechobee. [/FONT]

[FONT=Verdana,Arial, Helvetica]State water and wildlife managers are taking advantage of a drought by removing life-choking muck from the 730-square-mile lake, Florida's largest. Its removal over several months will return the bottom to a more natural sandy base and create clearer water and better habitat for plants and wildlife. [/FONT]

[FONT=Verdana,Arial, Helvetica][/FONT]


[FONT=Verdana,Arial, Helvetica]But the plan could create new pollution headaches on shore. [/FONT]

[FONT=Verdana,Arial, Helvetica]Arsenic levels on the northern part of the lake bed were as much as four times the limit for residential land, according to new tests from the South Florida Water Management District. [/FONT]

[FONT=Verdana,Arial, Helvetica]The Sun-Sentinel conducted independent tests that found even higher levels, making the muck too polluted for use on agricultural or commercial lands, the newspaper reported Sunday. The district declined to comment on the independent tests. [/FONT]

[FONT=Verdana,Arial, Helvetica]"We are evaluating how and where we dispose of it ... so we don't create a new problem someplace else," said Chip Merriam, the district's deputy executive director. [/FONT]

[FONT=Verdana,Arial, Helvetica]Options include using the muck as the base for nearby lakeside parking lots. [/FONT]

[FONT=Verdana,Arial, Helvetica]It has taken about six weeks to scrape the top 2 feet of muck from the lake. It amounted to about 1.9 million cubic yards -- enough to fill roughly 950 backyard swimming pools. [/FONT]
 
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Flipper

Flipper

Well-Known Member
Grrrrr....dachte, ich haette das link in der Mitte rausgenommen...ging wohl nicht...sorry....:0025:
 
admin

admin

Administrator
Teammitglied
Bei der Problematik stellt sich natürlich die Frage, wie das Arsen in diser Konzentration herkommt. Mir persönlich drängt sich da natürlich der Verdacht als Spätfolge von massivem Einsatz von arsenhaltigen Pestiziden/ Insektiziden in der rüheren amerikanischen Landwirtschaft, speziell im Wein- und Obstanbau auf. (http://de.wikipedia.org/wiki/Benutzer:Blech/Bleiarsenat) Evtl. das es dort durch Auswaschungen abgelagert wurde - meines Wissens wird Arsen nicht auf natürlichem Wege abgebaut.

Ist aber natürlich genauso möglich, das dort einfach ein noch bisher nicht bekanntes Arsenvorkommen befindet, wobei das im Schlamm schon recht ungewöhnlich wäre, soweit ich weiß :0025:
 
Flipper

Flipper

Well-Known Member
Du hast wohl Recht mit Deiner Annahme...

hier ist mehr....der Sun_Sentinel hat den Schlamm selbst testen lassen und einen hoeheren Wert gefunden als angegeben, auch heisst es erst, das Zeug kann nicht verwendet werden, doch dann wollen sie evtl. doch...
Lake Okeechobee's polluted muck creates disposal concerns

By Andy Reid
South Florida Sun-Sentinel
Posted July 8 2007



[FONT=Verdana,Arial, Helvetica]Elevated levels of arsenic as well as a soup of pesticides and other chemicals were among contaminants found in thousands of truckloads of muck recently cleaned out of Lake Okeechobee's drought-exposed bottom.[/FONT]

[FONT=Verdana,Arial, Helvetica]Arsenic levels on the northern part of the lake bed were as much as four times the allowable limit for residential land, according to newly released test results from the South Florida Water Management District.[/FONT]

[FONT=Verdana,Arial, Helvetica]Independent lab tests of a sample taken by the South Florida Sun-Sentinel show even higher levels on the eastern part of the lake, exceeding what would be allowed to be spread on commercial and agricultural land.[/FONT]

[FONT=Verdana,Arial, Helvetica]The district's test results are expected to guide decisions about how to dispose of mounds of pollution-laden muck, scraped away by bulldozers and backhoes brought in to take advantage of a drought that dropped the lake to a historic low.[/FONT]

[FONT=Verdana,Arial, Helvetica]Spreading the muck on agricultural, commercial or industrial land, as well as dumping it in landfills, is among the options proposed.[/FONT]

[FONT=Verdana,Arial, Helvetica]"We are evaluating how and where we dispose of it...so we don't create a new problem someplace else," said Chip Merriam, the district's deputy executive director.[/FONT]

[FONT=Verdana,Arial, Helvetica]While scraping away the muddy layer should breathe new life into the suffocating lake bed, disposing of the black ooze could spread harmful pollutants elsewhere.[/FONT]

[FONT=Verdana,Arial, Helvetica]For example, mounds of muck are being temporarily piled on land intended to become a water storage area that is one day expected to filter water headed to the lake.[/FONT]

[FONT=Verdana,Arial, Helvetica]Some of the muck also could end up as the base of a parking lot planned at a public campground and marina beside the lake.[/FONT]

[FONT=Verdana,Arial, Helvetica]The water management district contends the muck can be used safely, as long as it doesn't end up on residential land. The muck proposed to be used for the parking lot at the Okeetantie campground, on the northern rim of the lake, would be covered by asphalt and out of reach of children and other campers."A pesticide is a poison," said Herb Zebuth, a former scientist for the Florida Department of Environmental Protection, who has worked on Everglades restoration. "These are very complex chemical compounds. These things need to be taken seriously."[/FONT]

[FONT=Verdana,Arial, Helvetica]Also, testing for many contaminants may show that individually the levels don't raise concerns, but mix them together and the health and environmental consequences may be unknown, Zebuth warned.[/FONT]

[FONT=Verdana,Arial, Helvetica]The muck that coats the bottom of the lake results from phosphorus, nitrogen and other pollutants washed into the lake with stormwater that drains off farms and lawns.[/FONT]

[FONT=Verdana,Arial, Helvetica]Those pollutants fuel the growth of algae and other plants that die and settle to the bottom, forming a muddy layer that stifles the grasses that provide fish habitat.[/FONT]

[FONT=Verdana,Arial, Helvetica]Removing the muck restores the lake's natural sandy bottom and fosters the growth of tape grass, bulrushes and other native grasses needed for fish to spawn and birds to feed.[/FONT]

[FONT=Verdana,Arial, Helvetica]Six weeks of scraping away the top 2 feet of muck, mostly from the lake's northern and western edges, ended in June. During that time, district crews collected more than 1.9 million cubic yards of muck — enough to fill about 950 backyard swimming pools, according to the district.[/FONT]

[FONT=Verdana,Arial, Helvetica]Although as many as 30 tests by the district at six locations revealed an alphabet soup of pesticides and PCBs, all were at levels below the state's allowable standards.[/FONT]

[FONT=Verdana,Arial, Helvetica]The elevated level of arsenic in the muck raised the most concerns. Arsenic and other pollutants from pesticides can affect the lungs and nervous system, lead to cancer and at high enough levels can be lethal.[/FONT]

[FONT=Verdana,Arial, Helvetica]The district's test results show arsenic at most sampling sites exceeding levels allowed for residential land, but below state limits for commercial and agricultural land.[/FONT]

[FONT=Verdana,Arial, Helvetica]The state standard for allowable levels of arsenic on residential land is 2.1 parts per million, and the limit for commercial and agricultural land is 12 parts per million.[/FONT]

[FONT=Verdana,Arial, Helvetica]At Eagle Bay Island, on the northern part of the lake, tests showed arsenic levels at more than 9 parts per million. At Fisheating Bay, the western side of the lake, the arsenic levels hit 4.5 parts per million. Eagle Bay Marsh, also on the north side of the lake, had the lowest arsenic readings, topping out at 1.5 parts per million.[/FONT]





[FONT=Verdana,Arial, Helvetica]The district's tests indicate the muck can be used on agricultural land and other commercial applications, as intended, as long as recipients "understand what's in the material," said Susan Gray, the district's Lake Okeechobee program director.[/FONT]


[FONT=Verdana,Arial, Helvetica]"You don't want to take this material and spread it on someone's garden [but] there's no restriction for commercial use," Gray said.[/FONT]




[FONT=Verdana,Arial, Helvetica]A sample of muck tested for the Sun-Sentinel by A&L Southern Agricultural Laboratories Inc. of Pompano showed an arsenic reading of about 15 parts per million.[/FONT]

[FONT=Verdana,Arial, Helvetica]The sample came from exposed lake bed near Port Mayaca, on the eastern part of the lake, not far from where district officials have held news conferences about the drought's effects on the lake. The district is not digging muck from that site.[/FONT]

[FONT=Verdana,Arial, Helvetica]The district would not comment on Sun-Sentinel test results. Agency officials said their own findings were preliminary and contaminant levels could come down after more evaluation.[/FONT]

[FONT=Verdana,Arial, Helvetica]Much of the muck dug from the lake has been piled on dry land inside the earthen dike that surrounds the 730-square-mile lake.[/FONT]

[FONT=Verdana,Arial, Helvetica]Temporary storage sites outside the dike include property owned by Glades County, west of the Harney Pond part of the lake. Muck also is being stored on the district's Lemkin Creek property, pegged for a future water retention area, and a nearby private property at the lake's northern bend.[/FONT]

[FONT=Verdana,Arial, Helvetica]The Audubon Society supports the muck cleanup, but disposing of the muck north of the lake in areas that drain into the lake raises concerns about recycling the problem, said Paul Grey, a scientist for Audubon of Florida.[/FONT]

[FONT=Verdana,Arial, Helvetica]"There is a concern that, 'Oh great, it will just flow right back into the lake,'" Grey said. "If they do it wrong, it will be a problem."[/FONT]

[FONT=Verdana,Arial, Helvetica]Before dumping the muck at the temporary storage sites, district crews bulldozed earthen berms several feet high to surround the muck and contain any runoff. And though the sites are not lined, tests for "leachability" indicate the harmful materials are not likely to soak into the ground, said Lake Okeechobee program director Gray.[/FONT]

[FONT=Verdana,Arial, Helvetica]Storage at the Lemkin Creek property is just temporary and the muck should not leave any pollutants that would hamper plans for water storage there, Gray said.[/FONT]

[FONT=Verdana,Arial, Helvetica]Andy Reid can be reached[/FONT]

[FONT=Verdana,Arial, Helvetica]at abreid@sun-sentinel.com[/FONT]


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http://www.sun-sentinel.com/news/local/southflorida/sfl-flpmuck0708nbjul08,0,388972.story?page=1
 
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