The Lehigh River is nearly pristine. It wasn't always sparkling clean. Only 50 years ago the river was so polluted that the occasional swimmer would have to push aside various wastes with every stroke. The river was dead - no one fished the Lehigh River.

Because of numerous projects and programs, the Lehigh River has not only become free of obvious pollution but its rebirth has attracted paddlers and anglers, businesses and tourists which come to the clean outdoors of the Lehigh River Valley and have helped to revitalize its communities.

But the battle isn't over. The Lehigh River continues to be receive pollutants, drainage from the now abandoned coal mines that were once the economic engine of northeastern Pennsylvania. The largest source of abandoned mine drainage comes from the Lausanne Tunnel, located on the west bank of the Lehigh River half a mile north of Jim Thorpe.

To reduce the amount of heavy metals entering the Lehigh River from the Lausanne Tunnel, in 2004, a two stage artificial wetlands was constructed by the Wildlands Conservancy with funding from the Pennsylvania Department of Environmental Protection.

A century ago, the Lausanne Tunnel was constructed to drain water from the Panther Valley coal mines. Even though these mines have been closed for 50 years, they continue to drain into the Lehigh River and no way has been conceived to stop the flow.

The wetland project was not designed to handle the entire flow from the Lausanne Tunnel. It was designed to process 4,000 gallons per minute from a flow that varies between 7,000 and 16,000 cfs. The actual flow rate is not known and needs to be known so that a system capable of handling the total flow can be designed.

On Friday, Oct. 2, Matt MacConnell and Tom Gyory set about installing instruments to obtain the needed information.

MacConnell is president of the Lehigh River Stocking Association and Conservation Chair of the Lehigh Valley Group of the Sierra Club - Pennsylvania Chapter. He received funding for the project from the Sierra Club and the Wildlands Conservancy with the LRSA providing the installation.

The project is to install two flow measuring systems. One is located at the outflow of the bypass around the wetlands system; the second will be installed at the juncture of the stages of the wetland treatment system. The resulting data, which will be gathered for one year, will provide a picture of both the total flow and how much flow is being treated by the wetland.

"Today, we are installing an open channel flow meter and a rectangular weir in the bypass flow from the Lausanne Tunnel flowing into Nesquehoning Creek and then into the Lehigh River," MacConnell said. It will measure the untreated, raw AMD."

The rectangular weir, made from a large sheet of aluminum, was positioned at a narrow section of the discharge stream. MacConnell and Gyory, working in waders, set the weir plate and blocked it into place with stones and hydraulic cement.

Next, they set the measuring device, a float inside a pipe. As the water level upstream of the weir changes the float rises or falls, and this elevation is picked up by a transmitter wired to a solar powered data logger.

MacConnell plans to download the data each month and expects to have sufficient information to engineer an improved wastewater management system in a year.