Beach Closings-Sun Times

Trying to pinpoint the source of these bans often turns into an environmental whodunit.

We know the weapon is E. coli, bacteria that are typically harmless but serve as a clue that fecal contamination -- and the disease-causing microorganisms that go along with it -- might be lurking nearby. When E. coli levels get too high, the "No Swimming" signs aren't far behind.

But who, or what, is pulling the trigger? That's the mystery facing beach managers, environmentalists, public health officials and politicians across the Great Lakes.

AVOIDING E. COLI

Here are a few patterns experts have noticed when monitoring the bacterium E.coli in the water:

# E. coli counts generally peak in the early morning and tend to decrease throughout the afternoon.

# E. coli levels tend to be highest closer to the shore in knee-deep water.

# If the lake water is cloudy, there's a good chance E. coli is present.

# E. coli levels tend to climb after heavy rains.

# Long, straight beaches often have lower E. coli levels than beaches with coves, which can act like a teacup to trap the E.coli.

A growing body of evidence suggests that the leading suspect is above us -- and we don't mean everyone's favorite water-polluting whipping boy, Milwaukee.

Public Beach Enemy No. 1 appears to be gulls.

That's not to say sewage overflows and other factors don't shoulder some of the blame for shuttered beaches. But recent studies in Illinois have fingered gulls as the main E. coli contributor.

The scoop on droppings

A 2003 study using DNA fingerprinting found bird droppings were responsible for almost two-thirds of the E. coli culled from three Lake County beaches. Human waste and sewage came in a distant second, accounting for 20 percent of the bacteria. A total of 5 percent came from rats and dogs.

Gulls surfaced as a major culprit in a similar study done at Chicago's 63rd Street Beach, which over the last several years has consistently logged more swim bans than any other city beach.

The birds weren't always a problem for Chicago area bathers. Their ranks were low in the early 1900s, thanks to our appetite for gull eggs and a penchant for plumage in women's hats. Now that we don't eat them or wear them, their numbers are up. Same goes for swim bans, although experts chalk up much of that increase to more rigorous water monitoring in recent years.

"Back in 1970, there were only 300,000 nesting pairs for the entire Great Lakes," said Mark Pfister, aquatic biologist with the Lake County Health Department. "Now, there are about 800,000. Consider that 1 gram of gull feces can contain over 325 million E. coli. That's a lot of E. coli just sitting there, waiting to be washed in by waves and wind."

In an attempt to get a grip on the gull problem, Chicago's Environment Department will use a newly awarded $150,000 federal grant to try a few novel strategies this summer. One plan calls for stringing a series of thin wires about 15 feet above popular avian hangouts along the lakefront, such as DuSable Harbor, to dissuade birds from landing -- a strategy that was born in Canada.

"If it's successful, we'll definitely look at expansion," said Sadhu Johnston, acting commissioner of the department.

The department also plans to break out other weapons to lower E. coli counts in Lake Michigan to try to keep beaches open to bathers as many days as possible.

"On a hot summer day," Johnston said, "having a swimming ban is not something we like."

It's not us, Milwaukee says

Local politicians were quick to blame Milwaukee for a rash of beach closings in Chicago last June. The finger-pointing started after torrential rains the month before overwhelmed the city's sewer system, causing the Metropolitan Milwaukee Sewerage District to dump sewer water into waterways that feed Lake Michigan.

Officials originally estimated Milwaukee dumped 4.6 billion gallons of sewer water, but an investigation showed that the computer model that generated that estimate grossly inflated it. The actual number hovered closer to nearly 1.5 billion gallons, 477 million of which were raw sewage made up of rainwater as well as waste flushed down the toilet.

Findings presented last month at an International Association for Great Lakes Research conference backed Milwaukee's argument that the Wisconsin sewage did not spark Chicago's swim bans. A study noted that high E. coli levels were diluted long before they could reach Chicago's shores.

U.S. Rep. Mark Kirk (R-Ill.) asked the National Oceanic & Atmospheric Administration to weigh in on the matter, and that report is due in late July.

Unlike Milwaukee and plenty of other cities along the Great Lakes, Chicago's wastewater treatment plants don't discharge into waterways that drain into Lake Michigan, so sewage shouldn't get dumped into the lake. But it has happened. Heavy rains, which often leave high E. coli counts in their wake, have exceeded the Metropolitan Water Reclamation District's capacity to treat incoming wastewater. The resulting overflow makes its way into the lake when the district opens the locks at the Chicago River or Wilmette Harbor, for example, to stave off flooding.

During heavy rains in August 2002, the district opened three river locks, allowing river water and sewage to funnel into Lake Michigan. As a result, the Chicago Park District banned swimming at all of its 31 beaches for 48 hours.

All sewers not the same

A water reclamation spokeswoman said the district hasn't had to discharge into Lake Michigan since then, largely because the reservoirs and miles of caverns that make up the Deep Tunnel project have been able to hold sewage overflows, giving the wastewater treatment plants time to catch up.

The sewer system is different in Lake County, so anything that pours into the grates lining the curbs -- including runoff from fertilizers on lawns or radiator spills on driveways -- flows untreated into the nearest body of water. If you live east of Green Bay Road, that body of water is Lake Michigan.

"Not a lot of people know where those storm sewers lead," said state Sen. Susan Garrett (D-Lake Forest). "We're trying to educate them so they don't use them to throw away pet waste and other pollutants."

A 'smorgasbord' for waterfowl

Volunteers recently scoured some neighborhoods in Lake County, putting no-dumping warning decals on storm sewers and hanging reminders on people's doorknobs.

It doesn't always take a leaky septic system, sewer line break or sewage overflow to contaminate the water with human feces and the E. coli that tags along. Swimmers can bring E. coli into the water on their bodies, which is why health officials advise taking a shower before you go swimming. Kids with poopy diapers are a source of E. coli, as are boats that discharge their waste directly into the water instead of a designated pumping station.

People indirectly contribute to the gull problem, too.

"We found that 42 percent of what our volunteers are picking up from Chicago area beaches is either food or food packaging," said Cameron Davis, director of the Alliance for the Great Lakes, formerly known as the Lake Michigan Federation. "No wonder animals are heading to the beach. It's a smorgasbord."

The city will be posting signs this year at all beaches telling people not to feed the birds and to properly dispose of their food wrappers and other garbage that attracts waterfowl. It also plans to replace all of its beach trash cans with lidded containers that will make it harder for birds to treat the waste receptacles as a buffet table, Johnston said.

"People are feeding the gulls and leaving behind garbage, and they don't understand the connection about why the beach is closed the next day," Johnston said. "Residents can help keep swim bans from occurring."

Pfister says he thinks it's no coincidence that his North Point Marina Beach in Winthrop Harbor has logged the most swim bans this year.

"That's the beach where we see the highest concentration of gulls," he said. "Go to Sunrise Beach in Lake Bluff, and we recently had three days in a row that had zero E. coli. That beach has a very low gull population. These beaches are only 15 miles apart."

Gulls weren't as abundant at North Point Marina -- and neither were E. coli -- when the lake's water levels were higher. But as water levels dropped in recent years, the beach grew. And so did the birds' habitat.

"That beach is 255 percent bigger than it was in 1997," Pfister said. "The lake level just started to rise again, and I can't wait for water levels to get higher."