The compilation of best practices to reduce nutrient pollution would be available free from the Gulf Coast Community Foundation.

NOKOMIS — Unless the flow of nitrogen into Sarasota Bay is reduced and remediated, the water quality there may someday mirror that of the Indian River Lagoon on the East Coast of Florida — where the growth of healthy seagrass has been stymied by algae blooms.


Steve Suau, principal of Progressive Water Resources, said that over the past 20 years, the amount of total nitrogen in Sarasota Bay has doubled, according to data in the Sarasota County Water Atlas.


"It’s still not a high number, but this is reason to be concerned that we start reversing that trend," Suau told a gathering of Nokomis Area Community Association presidents Tuesday night.


#apolloLink{color:#000;background-color:#F4BE11;text-shadow: none;padding: 8px 15px 10px;font-family: 'Roboto', sans-serif;font-weight: 600;border-radius:10px;}

Read more environment stories


"What can happen as nutrients increase is that you start seeing the sea grass transition into macro algae and phytoplankton," Suau said. "That tends to remove sunlight to be able to get down and it kills the seagrass and a lot of aquatic life is dependent on that.


"This is what’s happening over in the Indian River Lagoon on the East Coast.


"It’s a brown algae and the concerning thing is they don’t know if they can ever get that bay back to the way it was — they don’t know how to do it," he added.


#apolloLink{color:#000;background-color:#F4BE11;text-shadow: none;padding: 8px 15px 10px;font-family: 'Roboto', sans-serif;font-weight: 600;border-radius:10px;}

Read more Venice news stories


Suau later said that that there have been indications that macro algae is being seen in the bays — something that’s reason to be concerned that too much nitrogen is going in, and that trend has to be reversed.


Suau, who just finished what he called a yearlong deep dive into research on nutrients in the area watershed, funded by the Gulf Coast Community Foundation, spoke to NACA along with Jon Thaxton, senior vice president for community investment at the Gulf Coast Community Foundation, as part of a series of water quality talks where they also previewed the "Community Playbook for Clean Water, an initiative of the Gulf Coast Community Foundation."


The playbook is being produced by Suau, along with David Shafer and Jennifer Shafer of Shafer Consulting.


Once finalized, the playbook will be available for free at gulfcoastcf.org for community associations, bureaucrats and elected officials, as they seek best practices to improve water quality throughout the state.


Suau and Thaxton — who also gave several talks on water quality last summer — will make a similar presentation to the Sarasota County Commission when it meets Tuesday at the Robert L. Anderson Administration Center at 4000 S. Tamiami Trail, Venice.


The duo will also speak on understanding and managing nutrients at 7 p.m. that night, in a program hosted by Hands Along the Water at the Unitarian Universalist Congregation of Venice, 1971 Pinebrook Road, Venice.


They spoke Monday night to the city of North Port environmental advisory board and hope to present the playbook to the elected officials in North Port, Sarasota and Venice as well.


Gulf Coast’s interest in developing environmental initiatives predated the persistent red tide bloom that plagued the area in 2018, Thaxton said but the red tide brought things into sharper focus — specifically with respect to the impact excess nutrients have on red tide growth.


"It was causing red tide to become of greater intensity, longer extent and longer duration as well," Thaxton said.


#apolloLink{color:#000;background-color:#F4BE11;text-shadow: none;padding: 8px 15px 10px;font-family: 'Roboto', sans-serif;font-weight: 600;border-radius:10px;}

Read more stories by Earle Kimel


Because of data collected in Sarasota County, Suau was able to compare watersheds such as the relatively pristine Deer Prairie Slough and the more urban Whitaker Bayou.


Deer Prairie Slough is a Myakka River tributary that mostly flows through preserved land, while Whitaker Bayou flows through mostly urban sections of Sarasota.


Suau said it was possible to view several years of data to see what percentage of nitrate vs nitrogen is present in the water.


"Bottom line, what we found, the natural watershed only had about 5 percent of the nitrogen in this category as nitrate," Suau said. "The more developed watershed it was up to 28 percent."


There are a variety of solutions to reduce the flow of nutrients into the bay.


The most high-profile, and cost-effective, solution now being pursued by Sarasota County is the conversion of its wastewater treatment plants to AWT standards by removing nitrogen — something that the city of Sarasota already does at its treatment plant.


The other five sewage treatment plants — Bee Ridge, Central and Venice Gardens, for Sarasota County, and the cities of North Port and Venice all exceed the AWT nitrogen standard of 3 milligrams per liter, according to Florida Department of Environmental Protection 2018 discharge monitoring reports.


Sarasota County is already planning a $157 million upgrade of the Bee Ridge plant to convert it to AWT standards. While such upgrades don’t come cheap, they provide the greatest amount of nitrogen reduction per dollar spent.


Gulf Coast’s playbook also discusses efforts in other areas of nutrient reduction, including using denitrification systems with organic carbon — as simple as sawdust and wood chips — to reduce the nutrient content of septic system effluent.


Thaxton hopes that Sarasota County — which has already made great strides in reducing fertilizer use with its fertilizer ordinance — can become a model community for nutrient management in the state of Florida.


"If we were to do everything that Steve and the team is suggesting and we were to restore nutrient levels as close as we possibly can to pre-human settlements and they don’t impact red tide — and I don’t think that’s going to happen but let’s just assume that they don’t — oh my God, we’re stuck with clean water," Thaxton said. "Our goal is clean, healthy water for Sarasota County and we can achieve that through our playbook."