From the Democrat & Chronicle:
After the Great Lakes cleanup of the 1970s, pollution levels plummeted, fish began to thrive and algae receded to a minor annoyance.
But three decades after that massive, multibillion-dollar cleanup, the waters of four of the five Great Lakes are once again plagued by smelly, slimy algae.
Lake Ontario's shoreline has become distinctly murky. Some describe it as a bathtub with a dirty ring around it.
The stringy green algae known as cladophora is once again washing up on shore — fouling boat propellers, shutting down an upstate nuclear power plant and closing beaches.
Cladophora-related closures at Rochester's Ontario Beach have increased fourfold in recent years.
Health officials are concerned that decomposing cladophora provides a breeding ground for pathogenic bacteria. And some U.S. scientists worry about the increase of cyanobacteria, which can produce dangerous, even deadly, toxins.
The new growth of these algae and bacteria, scientists say, is driven by an abundance of phosphorus in some near-shore areas and connected bays and ponds, particularly around Rochester and points west.
Concern about algae and weed growth has made phosphorus a hot topic throughout North America and spurred new government controls on phosphorus discharges. But New York state is lagging.
A dozen states in recent years have adopted or considered legislation to address phosphate content in dishwashing detergent. Dozens of Great Lakes cities and counties, and some entire states, also have banned phosphorus in lawn fertilizer in the last few years.
Neither of these tactics has taken root in New York state.
Phosphorus was the main target of the 1970s cleanup. Improving sewage treatment and banning phosphates in laundry detergent proved effective — in the deep waters in the middle of the lake.
But water near the shore now has high levels of the pollutant. Discovering the cause and the remedy for this problem is a key goal of research being conducted by academic and government scientists....
Phosphorus, a highly reactive element obtained by mining phosphate rock, was named a pollutant of concern by the U.S. and Canada in their 1972 Great Lakes Water Quality Agreement. An ingredient of fertilizer and cleaning compounds, phosphorus was discharged into the lakes in large quantities. The agreement called on the two nations to tighten control of phosphorus at sewage treatment plants and reduce phosphate additives to laundry soaps.
Those steps and more were taken. For example, New York was among several Great Lakes states that had essentially banned phosphates in laundry soap by the mid-1970s....
As phosphorus tapered off, so did algae....
But in the late 1990s, citizen complaints about fouling of beaches and shorelines began to recur. When Howell surveyed the lake bottom in 2000, "there was scads of the stuff there," he said, and complaints became even more frequent after that.
No systematic survey has been made in U.S. waters, but there is no doubt that the algae is running wild again....
In the 15 years from 1978 to 1992, the beach averaged fewer than two days a season when algae sent swimmers home. In the 15 full years since then, the average has been almost eight algae closures per year.
"This is a newer problem — it's a problem we actually haven't seen for many years now," Makarewicz said of the algal buildup at the shoreline. "Lots of places are problem spots. This stuff is so thick in some places you can't move a boat through it."
The Fitzpatrick nuclear power plant in Oswego County had to shut down unexpectedly three times last September and October because cladophora overwhelmed protective screens and clogged water intakes, reducing the flow available to cool the reactor, according to reports submitted to the U.S. Nuclear Regulatory Commission.
The algae coats sand or rocks with a slippery scum. As it rots, algae emits an odor so foul that shoreline residents must shut their windows in mid-summer.
But it's not just aesthetic concerns that prompt officials to shut down beaches, said Charles Knauf, an environmental health project analyst for the Monroe County Health Department. Mats of cladophora and other algae appear to provide a breeding ground for harmful bacteria. Organisms such as E.coli that come from the digestive tracts of mammals have been found at the beach during algae events, Knauf said.
"The concern now is they can reproduce in these algal mats," he said. "The thought is that it's an 'artificial gut' inside these mats, or in the sand."....
Another part is to sample at pre-determined spots on the U.S. and Canadian shorelines in an effort to learn how much new phosphorus is flowing into the lake from various sources, including sewage treatment plants, stormwater overflows into creeks and rivers, leaking septic tanks, and runoff from fertilized grass and farm fields laden with nutrients. Typical lawn and garden fertilizer contains phosphorus, as do some farm fertilizers.
Although phosphorus has been largely eliminated from laundry detergents, phosphates still are added to dishwasher soap and other cleaners...
Phosphates in dishwasher detergent have been banned by law in some U.S. states, and the federal government in Canada just proposed new regulations to eliminate phosphates from all household cleaning products.
Various locations around the Great Lakes have implemented restrictions on phosphorus in lawn fertilizers.
Such things have been discussed informally in New York, but not adopted, Zelazney said.
The DEC applies a more stringent, holistic approach to regulating pollution in some smaller water bodies, including two small bays connected to Lake Ontario. But the program hasn't been used to address phosphorus in Lake Ontario.
Sunday, August 24, 2008
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment