blue green algae Blue-green algae levels in Geist Reservoir triggered “High Health Risk” alerts in May this year following the seasonal warm up. The health alert is now ongoing and will likely remain in effect until late fall.

This information comes to us from the Indiana Department of Environmental Management and the Center for Earth and Environmental Science at Indiana University-Purdue University Indianapolis. Their assessment is based on the World Health Organization’s guidelines for safe recreational water which state that the presence of blue-green algae, or cyanobacteria, at levels greater than 100,000 cells/ml pose a high health risk.

What is a “High Health Risk for Recreational Waters?”

According to the Indiana State Department of Health, exposure to blue-green algae during recreational activities such as swimming, wading, and water skiing can lead to rashes, skin and eye irritation, and other uncomfortable effects such as nausea, stomach aches, and tingling in fingers and toes.

“We recommend people use caution when swimming, skiing, or participating in other recreational water activities,” said Jennifer House, DVM, veterinary epidemiologist at the Indiana State Department of Health. “Avoid coming into direct contact with the algae and try to avoid swallowing water if at all possible. It is always a good idea to take a bath or shower with warm, soapy water after coming in contact with untreated water in ponds and lakes, especially before preparing or consuming food. Pets should not be allowed to swim in or drink untreated water from these sources.”

Drinking Water is Safe

Geist Reservoir was designed with a holding capacity of about 7 billion gallons to help supply Central Indiana with drinking water. According to Lou Ann Baker, Vice President of Communications and Community Affairs at Veolia Water Indianapolis, “Standard drinking water treatment effectively removes algae and its byproducts from your drinking water. While some customers can detect taste differences caused by higher levels of taste and odor compounds produced by the algae, the water still meets all state and federal water quality standards and is safe to drink.”

What is Causing the Algae Blooms?

A major limiting factor for algae blooms is available nutrients – especially phosphorus. Agricultural and urban fertilizer runoff are major contributors of phosphorus as are pet waste, leaves and grass clippings. All have high amounts of nutrients that move into waterways and the reservoir following rain events.

What Can We Do?

If you fertilize your lawn, use a phosphorus free product. True Green has been P-free for the last few seasons. Scott’s offers P-free options and its entire Turf Builder line will be P-free by 2012. Many other suppliers now offer P-free options. Please make sure you are using the right product. The middle number on the bag should be a “0”.

Make sure that grass clippings are composted back into your lawn and not thrown onto sidewalks, streets, or the reservoir. The phosphorus in the lawn clippings gets returned to the lawn where it is recycled. Clean up after your pet and dispose of waste properly.

Homeowners may also want to adopt landscape practices that lessen the impact to our water supply. These practices are encouraged by our county’s soil and water conservation district and include rain gardens, barrier plantings at water’s edge, and landscaping with native plants. Lawn roots are about two inches deep. Native Black Eyed Susans, by comparison, root up to eight feet deep and are much more effective in controlling erosion and slowing runoff.

At a regional level, the Upper White River Watershed Alliance, which includes watersheds draining into Eagle Creek, Morse, and Geist Reservoirs, is finalizing a series of watershed management plans. A watershed management plan describes sources of water quality problems and identifies corrective and preventative actions for residential, agricultural, governmental and commercial stakeholders in the area.

Statewide, Indiana recently banned phosphorus in our dishwasher detergents. This will reduce the phosphorus load in our waters by up to 3% according to Dr. Bill Jones of Indiana University School of Public and Environmental Affairs. In 1974, Indiana became the first state in the union to phase out phosphorus from laundry detergent.

While a reduction in nutrient load is necessary, it will not produce an immediate fix. According to Dr. Lenore Tedesco of IUPUI, “Geist reservoir has very high levels of phosphorus in the waters. Our research shows that phosphorus levels tend to increase throughout the summer indicating that there are continual additions to the reservoir that are likely sourced from residential lawns and gardens. There is an important role for homeowners both living on the reservoir and in the neighborhoods surrounding the reservoir. Reducing and/or eliminating fertilizers, managing yard waste and cleaning up after pets are all important steps.

For information about how your lawn is connected to our water supply, check out, a collaboration between Upper White River Watershed Alliance, IUPUI, and some additional watershed groups. While you’re there, take the phosphorus free pledge. Team Geist is in 7th place.

Please see our website, for additional information including links to local demonstration properties that feature watershed friendly landscape practices.