[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Fw: support for predictive models for beaches

attached doc is press article on how rutgers univ in nj is looking at ocean enterococcus sampling performed by the county from last year and comparing it to their current and wind information - a first step towards predictive modeling systems already established along the great lakes

rutgers codar web site is


William Simmons
Environmental Health Coordinator
Monmouth County Health Dept
3435 Rt. 9
Freehold N.J. 07748
Phone (732)431-7456
Fax  (732)409-7579

----- Original Message ----- From: "Shannon Briggs" <briggssl@michigan.gov>
To: <beachnet@great-lakes.net>
Sent: Tuesday, July 31, 2007 1:39 PM
Subject: support for predictive models for beaches

No-swim advisories often come a day too late for the beach-bound

Monday, July 30, 2007
By Jeff Alexander

Few things can spoil a day at the beach like a sign warning that the water is unsafe for swimming.

But consider this: Existing beach monitoring programs, which tell swimmers to stay out of the water when bacteria levels pose potential health threats, are outdated the minute they are posted, health officials said. Current beach closure notices are the equivalent of sounding a fire alarm the day after a fire.

That's because beach closures are based on water monitoring data from the previous day or, in some cases, from two days earlier. By the time warning signs are posted, water quality at a beach could be fine -- but no one would know until the next day because it takes 24 hours to culture bacteria samples.

"The technology really limits us right now," said Adam London, Ottawa County's environmental health director. "By the time we have the knowledge we need to make a decision (about closing a beach), that pollution risk may not be present any longer."

Those shortcomings are the reason local and federal officials are working to develop ways to forecast water-quality conditions at Great Lakes beaches. If current studies pan out, local and federal officials might be able by next summer to forecast water-quality conditions before people head to Lake Michigan beaches.

"The goal is to let people know when they wake up in the morning whether the beach is going to be clean that day," said Gary Fahnenstiel, a senior ecologist at the National Oceanic and Atmospheric Administration's Lake Michigan Field Station in Muskegon. "All the current methods to address bacterial contamination on beaches are based on conditions that were present 24 to 48 hours ago."

Elevated bacteria readings have closed beaches this summer in Muskegon and Ottawa counties, areas where beach closures relatively are unusual. Health officials last Friday posted a no-swimming advisory at Grand Haven City Beach and Grand Haven State Park after tests showed elevated E. coli levels. That advisory came on the first day of Grand Haven's popular Coast Guard Festival.

London said computer models being developed by scientists at NOAA's Great Lakes Environmental Research Laboratory and Michigan State University could give health officials the tools they need to more accurately assess bacterial water pollution risks at Lake Michigan beaches.

"Having accurate and effective forecasting tools will allow us to make better management decisions," London said. "It would empower health officials and beach managers to say with greater accuracy whether we need to close a beach."

Developing that water quality forecasting tool is a tall order, said Dave Schwab, a NOAA oceanographer. "This is new territory," he said.

Bacterial water pollution at Great Lakes beaches can come from shore birds, pet feces, sewer overflows and farm runoff. Elevated concentrations of bacteria in water can pose human health threats.

Researchers focused their work on the Grand River because it is one of the largest sources of pollutants entering Lake Michigan, Fahnenstiel said. The river also has a well-defined plume because it pumps so much sediment into the lake every day.

Scientists are in the third year of a project that involves tracking where water and pollutants in the Grand River go after the river flows into Lake Michigan.

Using dye to track water currents and aerial photographs to observe the plume, researchers have figured out how the plume moves in response to wind and water currents. The next step is figuring out what causes bacteria levels to rise in the river and how to predict that in the future, Schwab said.

The NOAA project is part of a growing trend among government agencies to focus more on research projects that help scientists forecast future environmental conditions. Similar efforts decades ago allowed meteorologists to develop more accurate weather forecasts, Schwab said.

A series of aerial photos by local photographer Marge Beaver dramatically illustrate how the coffee-colored Grand River plume moves in Lake Michigan. South winds can push the plume to Muskegon; north winds can push it to Pigeon Lake, near Holland, Schwab said.

A side-by-side comparison of Beaver's photos and computer predictions of how the plume will move shows the forecasting tool is very accurate.

Schwab said researchers were surprised to learn that the plume is only two to three feet thick as it floats across the surface of Lake Michigan before dissipating.

"Close to the river mouth, the plume seems to be acting like an oil slick," Schwab said. "It's very thin and sitting on top of the colder lake water."

On most days, London said, the brown color in the Grand River plume is harmless silt that has washed off the landscape, not sewage from Grand Rapids or manure from area farms.

In the future, London said, if there was a heavy rain event that triggered a combined sewage overflow in Grand Rapids, coupled with winds that pushed the river plume ashore at Grand Haven City Beach, it might prompt health officials to close that beach.

©2007 Muskegon Chronicle © 2007 Michigan Live. All Rights Reserved.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
beachnet is hosted by the Great Lakes Information Network:
To unsubscribe from this list: send mail to majordomo@great-lakes.net
with the command 'unsubscribe beachnet' in the body of your message. No
quotes or subject line are required.
About : http://www.great-lakes.net/lists/beachnet/beachnet.info
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Attachment: icms grant and ccmp - app.doc
Description: MS-Word document