Lessons In Protecting Against Nutrient Pollution

Earlier this month, the U.S. EPA released findings from its National Lakes Assessment (NLA) based on 2012 data that found 40 percent of the country’s lakes have excessive levels of phosphorus and 35 percent have excessive levels of nitrogen. Microcystin, an algal toxin, was found in 39 percent of lakes. Compared to the previous version of the NLA conducted in 2007, most indicators of nutrient pollution have not changed, prompting renewed efforts to alter the rate at which this pollution occurs.

“We are seeing how nutrient pollution is degrading our drinking water and increasing the prevalence of algal blooms fouling our recreational waters,” an EPA spokesperson said. “The NLA offers a unique opportunity to frame discussions and planning strategies for the protection and restoration of lakes across the United States.”

A latest effort to put an end to nutrient pollution was the agency’s webcast seminar, “Understanding Nutrient Issues Affecting Ohio’s Inland Lakes.” By demonstrating to attendees how intervention efforts have unfolded in possibly the most notorious nutrient-plagued state, the agency hoped to offer lessons that could be applied throughout the country.

“The EPA recently helped the State of Ohio develop preliminary lake management plans based on the state’s monitoring data for Buckeye Lake, Lake Alma, and Kiser Lake as models for other lake management plans,” the spokesperson said. “To ensure a broad benefit of our support to Ohio, we asked that the project work plan include a webinar or similar opportunity to transfer the project results to a wider audience of interested state and local water quality managers and the public.”

More than 400 attendees heard from environmental scientists with experience addressing nutrient problems in drinking water sources, including Rick Wilson, an environmental specialist with the Ohio EPA who has supported the state’s lake program for years, and Dr. Harry Gibbons, a scientist with Tetra Tech who has led management and restoration for over 350 lakes, reservoirs, and stream and river systems.

A publicly available PowerPoint from the webinar shares information on Ohio’s lake monitoring program, lessons learned from efforts at Buckeye Lake, case studies from Kiser Lake and Lake Alma, an assessment of the current data gaps and monitoring recommendations to fill them, recommendations for managing nutrient loading to lakes from watersheds, and recommendations for internally maintaining water quality and limiting the occurrence of harmful algal blooms.

“The webcast described the types of data that states and others need to collect in order to understand if a lake or other waterbody is impaired by nutrients,” said the agency spokesperson, pointing to the EPA’s handbook and quick guide for “Developing Watershed Plans to Restore and Protect Our Waters” and an “Introduction to Watershed Planning” as sources of more information.

Attendees were also instructed to identify and work with appropriate stakeholders when pursuing nutrient reduction efforts, such as public officials, water department officials, state park officials, the farming community, local soil and conservation districts, and lake associations.

“It is critical to engage these stakeholders as they have important information about the issues affecting their local lakes and also will be critical to getting the buy-in needed to implement the solutions,” the spokesperson said.

The EPA also has two guides for engaging stakeholders in protecting a local watershed.

Finally, attendees heard about the key takeaways from efforts in Ohio to battle back local nutrient pollution and harmful algal blooms:

• Internal phosphorus loading in shallow lakes may be more important than external loading in short-term summer algal bloom production.
• In shallow lakes, modest flux rates from sediments can result in high water column concentrations due to shallowness, which can lead to harmful algal blooms.
• Watershed best management practices will only address part of the increase in external phosphorus loading due to land use, compared to historical phosphorus loading.
• In-lake management practices like phosphorus inactivation have been proven effective in shallow lakes for internal phosphorus loading and harmful algal blooms, regardless of how closely the watershed is managed.
• Interested parties must always work with watershed best management practices to reduce overall loading to lakes and reservoirs if nutrient reduction will be successful long-term.