Friday, August 31st, 2007
Grand Lake is first to get quality check
Final EPA report on water is long way off
By Nancy Allen
Linda Merchant-Masonbrink of the Ohio EPA uses a net to collect the microscopic. . .
The water in Grand Lake was tested Thursday as part of a first-ever Survey of the Nation's Lakes.
The 13,500-acre lake is among 19 in Ohio and 909 across the United States randomly selected for the testing.
Ohio EPA officials Thursday took a boat on the lake and tested the water for clarity (suspended soil particles and algae), the species, composition, diversity and number of microscopic plant and animal life, mercury, the possible existence of algal toxins, fecal bacteria, and water chemistry, Linda Merchant-Masonbrink of the Ohio EPA's Inland Lakes and Source Water program said.
Some raw data should be available in spring 2008, but a final report analyzing what the results mean will not be available until some time in 2009, said Masonbrink.
"We don't have any results yet, but what we could tell today looking at the lake is there is a fair amount of algae in the lake," Masonbrink said.
Part of the testing also will be done for the existence of a toxin produced by some types of blue-green algae. Blue-green algae is the predominant type of algae in Grand Lake, previous, local water quality testing has shown.
Mandated by Congress and sponsored by the U.S. EPA and U.S. Geological Survey, the survey's purpose is to determine and compare conditions in inland lakes, ponds and reservoirs in the lower 48 states.
Separate Ohio EPA water quality testing done in recent years shows that excess nutrients entering the lake mostly from farmland, the predominant land use in the 71,862-acre watershed, cause large blooms of blue-green algae. That same testing determined that the local watershed is one of the most degraded in the state.
Masonbrink said EPA officials could know this spring if the toxin is present in Grand Lake. But even if it is, it is hard to know what that means, because the toxin is transient and can come and go, she said.
"It's not well understood, but when the toxin is produced, it is a liver toxin that could produce liver cancer and tumors over time and contact dermatitis (skin rashes)," she said. "This would be good to know if it's here in the lake since it is used for drinking water."
A Secchi disk reading done on the lake water showed the disk was visible 10 inches below the water's surface, Masonbrink said.
The black and white disk attached to a rope is lowered into the water to measure water clarity.
A 21/2 to 3-feet deep core of muck also was taken from the lake's bottom, which Masonbrink called a "time capsule" that will tell EPA officials what has happened with phosphorous levels in the lake throughout the years. Phosphorous is a nutrient found in high levels in the lake that impairs water quality.
It has been 10 years since the Ohio EPA conducted a water quality study of the state's inland lakes. The study will take a closer look at the state's lakes to identify ones that are impaired and determine how to make them healthy. While lakes will be the focus, attention also will be paid to streams draining into them, she said.
Masonbrink said through the course of this national study, Ohio EPA officials are learning new water testing techniques that will help them when the OEPA begins its own inland lake sampling program next year in Ohio.