In response to the deterioration of the health of the Indian River Lagoon (IRL) along Florida’s east coast, Brevard County residents approved a sales tax referendum in 2016 to fund the Save our Indian River Lagoon Project Plan for ten years. The plan focuses on reducing nutrient inputs to the lagoon through stormwater and wastewater retrofit projects as well as fertilizer education and restoration efforts. To reduce new sources of groundwater pollution, Brevard County Commissioners recently adopted a temporary ordinance limiting new conventional septic systems within 50 meters of the IRL, connected tributaries, and surrounding barrier islands. To produce a permanent ordinance that balances protection of water quality with other socio-economic factors, further analysis was needed to better understand which areas of the county are contributing the most septic pollution to the IRL. In May 2018, Applied Ecology was contracted by Brevard County to assist in the analysis of the potential loading impact of Onsite Wastewater-Treatment and Disposal Systems (OSTDS) to the Indian River Lagoon and Connected Waterways in Brevard County. The analysis is based on extensive predictive modeling using the ArcGIS-based Nitrate Load Estimation Toolkit (ArcNLET) and uses a simplified conceptual model of groundwater flow and transport customized with County-based input data. The results of this analysis provided Brevard County with support to implement a permanent, legislative ordinance instead of a temporary moratorium. To learn more about the results of this project, go to our Septic Moratorium Analysis Case Study page!