Chemical improves quality of water in Spring Lake

[Hamilton Reef]

Spring Lake - Chemical improves quality of water in Spring Lake

http://www.mlive.com/news/chronicle/ind ... xml&coll=8

02/27/08 By Jeff Alexander jalexander@muskegonchronicle.com

A chemical treatment used to combat algae in Spring Lake has dramatically improved water quality in the lake, according to two new studies.

The Spring Lake Lake Board paid $1.3 million to pump more than 1 million gallons of aluminum sulfate, or alum, into much of the 1,298-acre lake in late 2005. The treatment was aimed at reducing the amount of phosphorus in the lake, which fueled massive algae blooms that made the water's surface look like it was covered with bright green paint.

In the two summers since the alum treatment, there have been no major algae blooms on the lake, water clarity has improved and phosphorus concentrations have dropped by more than 50 percent, according to a study by Progressive AE, a Grand Rapids engineering firm.

"There's been a huge difference -- we haven't seen the algae that looks like green paint on the water's surface and I hope we never see it again. That was disgusting," said John Nash, the Spring Lake Township Supervisor and chairman of the lake board.

"There were times in the past when I could only see down about 15 inches in the water," Nash said. "Now I can see down five feet sometimes."

Cheryl Mendoza, a lakefront property owner, said she has noticed a big improvement in water clarity since the alum treatment. "The lake is clearer now than it has ever been in the six years we've lived there," she said.

Summer algae blooms were an almost annual event on the lake prior to the alum treatment. Some years there were two or three large algae blooms, Nash said.

The liquid alum sprayed in deeper areas of the lake settled on the bottom, where it bound to phosphorus in sediments. By chemically tying up the phosphorus, the alum reduced the amount of phosphorus available to feed aquatic plants and algae in the lake.

Prior to the treatment, the highest phosphorus concentration in the water was 786 parts per billion. That dropped to 132 parts per billion two years after the treatment, according to Progressive AE's monitoring data. Average phosphorus concentrations prior to the treatment were 101 parts per billion; that dropped to 39 parts per billion last summer.

A separate study by Grand Valley State University's Water Resources Institute found similar results. But the GVSU study concluded that excessive amounts of phosphorus are still entering the lake from the surrounding landscape and tributaries.

"The lake is healthier, in general, in terms of water quality conditions," said Alan Steinman, director of GVSU's Water Resources Institute.

"But as I said before the alum treatment, this was not a panacea," he said. "If you continue to put phosphorus into the lake, with fertilizers and storm water runoff, that's going to create more algae, which will sit on top of the alum and create a whole new problem."

The only noticeable drawback of the alum treatment was that it reduced the number of beneficial insects living on the lake bottom, according to the GVSU study. Those insect populations will likely rebound over time, Steinman said.

The alum treatment was expected to improve water quality in the lake for up to 20 years. That time frame could be shortened unless individuals and communities around the lake reduce the amount of phosphorus entering the water, Steinman said.

Nash said efforts to reduce phosphorus inputs to the lake are ongoing. Ottawa County, for instance, recently banned the sale of phosphorus-based lawn fertilizers.

Local officials are also working with area farmers to reduce manure and fertilizer runoff into Norris Creek, which flows into Spring Lake. And Nash said officials in Fruitport, where homeowners still rely on septic tanks that can leak sewage into the lake, are warming up to the idea of connecting homes and businesses to a municipal sewage treatment system.

Absent those costly changes, Nash said he believes the current water quality in Spring Lake is probably as good as it will get.

[Will Schultz]

Hmmm... I wonder how much money they spent on getting the property owners to stop fertilizing their lawns?

[Hamilton Reef]

The Spring Lake Lake Board is getting the zero phosphorous information out to its members (newsletters & meetings) and Ottawa County passed the Zero Phosphorous Ordinance.