Using data to visualize vulnerabilities along the SJR

Sanitary Sewage Overflows (SSOs), Impaired Waters, Septic Tanks, Aquifer Vulnerability, Soil Drainage Classifications, and JEA’s owned properties.

H1. Introduction

In an effort to provide the public with information about aspects of Jacksonville sewage infrastructure, soils, and aquifer vulnerability, this section highlights a series of maps that show data from various sources, and periods. The maps for this section were made by Dr. Ashley Johnson*, Department of Geography, Jacksonville University.

*Ashley Johnson received her Ph.D. in Interdisciplinary Ecology from the University of Florida in 2004. In addition to her Ph.D., she was awarded a certificate in geospatial sciences. She began teaching at JU in the biology department in 2009 and is currently a professor of geography and the environment as well as sustainability. She teaches a variety of courses, but focuses on technical geography courses, or geographic information systems. Her areas of research include coastal, marine and inland water planning, describing spatial barriers to health care, and geography education in upper elementary and middle schools. In addition, she is interested in researching policy solutions to pressing environmental issues, including harmful algal blooms, management and development of working waterfronts, and sea level rise.  She has lived in Jacksonville for 15 years.

H2. SSOs and Impaired Water Bodies

This map indicates sanitary sewer overflow points as reported on Jacksonville Electrical Authority’s (JEA) website (https://www.jea.com/Outage_Center/Environmental_Incident_Reporting/). In addition, the map contains information on the total gallons of overflow at each point. The map also includes water bodies that are impaired based on a variety of biological, chemical and physical parameters. These data were downloaded from the DEP open data portal (https://geodata.dep.state.fl.us/).

Map 1. Sanitary sewer overflows (January 2018-Feburary 2019) and impaired water bodies (July 2018).

Map of Sanitary Sewer Overflows by Council District

H3. Water Impairment

This map illustrates additional water impairment measurements, including chlorophyll-a (an indication of primary production and phytoplankton) and physical and chemical parameters, bacteria and metals being two of the most prevalent impairments (as of July 2018).  These data were downloaded from the DEP open data portal (https://geodata.dep.state.fl.us/).

Map 2. Impaired waters Lower St. Johns River, July 2018.

This map illustrates additional water impairment measurements, including chlorophyll-a (an indication of primary production and phytoplankton) and physical and chemical parameters, bacteria and metals being two of the most prevalent impairments (as of July 2018).
Note: Although the mainstem is not included, it is impaired for nutrients and metals (saltwater).

H4. Septic Tank maps

All of these maps indicate the presence of septic tanks in Duval County. The maps are differentiated based on what type of septic tanks are shown and/or where they are located in relation to vulnerable resources. This map set contains all onsite sewage treatment and disposal systems (OSTDS) in Duval County during 1992-2012 (Map 3); all abandoned OSTDS in Duval County during 1992-2012 (Map 4); all existing septic systems during 1992-2012 (Map 5); all septic holding tanks during 1992-2012 (Map 6); all new septic systems installed during 1992-2012 (Map 7); and repairs on septic systems during 1992-2012 (Map 8). For additional reference, all septic tank points were overlaid with two additional data sets: Surficial aquifer classification (Maps 9 and 10 – note that the higher the DRASTIC index, the more vulnerable the aquifer is to contamination); Soil drainage classifications (Map 11); and Jacksonville Electric Authority owned parcels (Map 12). The OSTDS, aquifer vulnerability, and soils data were downloaded from the Florida Geographic Data Library, maintained by GeoPlan at the University of Florida (www.fgdl.org). The JEA owned parcels data were derived from the parcels database maintained by the Florida Department of Revenue.

Map 3. All septic tanks 1992 – 2012.

Map of all onsite sewage treatment and disposal systems (OSTDS) in Duval County during 1992-2012
Data source: Florida Geographic Data Library, GeoPlan, University of Florida (www.fgdl.org).

Map 4. Abandoned septic tanks 1992 – 2012.

Map of all abandoned OSTDS in Duval County during 1992-2012
Data source: Florida Geographic Data Library, GeoPlan, University of Florida (www.fgdl.org).

Map 5. Existing septic tanks 1992 – 2012.

Map of  existing septic tanks 1992 – 2012.
Data source: Florida Geographic Data Library, GeoPlan, University of Florida (www.fgdl.org).

Map 6. Existing septic holding tanks 1992 – 2012.

Map of Existing septic holding tanks 1992 – 2012.
Data source: Florida Geographic Data Library, GeoPlan, University of Florida (www.fgdl.org).

Map 7. New septic tanks 1992 – 2012.

Map of new septic tanks 1992 – 2012.
Data source: Florida Geographic Data Library, GeoPlan, University of Florida (www.fgdl.org).

Map 8. Existing repaired septic tanks 1992 – 2012.

Map of existing repaired septic tanks 1992 – 2012.
Data source: Florida Geographic Data Library, GeoPlan, University of Florida (www.fgdl.org).

H5. Aquifer Vulnerability maps

The vulnerability of Florida’s surficial aquifer is important to understand. This map set attempts to illustrate the spatial variation in the vulnerability of the aquifer. The surficial aquifer is shallow and found near the surface, the thickness of the surficial aquifer system is typically less than 50 feet. The DRASTIC index was developed by the EPA to assess groundwater aquifer systems’ vulnerability to contaminant pollution. Parameters analyzed in the index include depth to water table, net recharge, aquifer media, soil media, topography (slope), impact of vadose zone media, and hydraulic conductivity. The higher the value, the more vulnerable the aquifer is to contaminants. The mean index value for the state of Florida is included on the Map 7, for which it is noted that the majority of Duval County’s index values are above the state mean, indicating the County’s increased susceptibility to polluting the aquifer. Map 8 in this set affirms the critical nature of the problem by showing the aquifer and the presence of septic tanks in the area.

Map 9. Surficial Aquifer DRASTIC index.

Map showing the critical nature of the problem by showing the aquifer and the presence of septic tanks in the area.
Data source: Florida Geographic Data Library, GeoPlan, University of Florida (www.fgdl.org).
Note: The higher the DRASTIC index, the more vulnerable the aquifer is to contamination.

Map 10. Aquifer with septic tanks 1992 – 2012.

DRASTIC Aquifer map with septic tanks 1992 – 2012.
Data source: Florida Geographic Data Library, GeoPlan, University of Florida (www.fgdl.org).
Note: The higher the DRASTIC index, the more vulnerable the aquifer is to contamination.

Map 11. Soil drainage classifications with septic tanks 1992 – 2012.

DRASTIC Map of  soil drainage classifications with septic tanks 1992 – 2012.
Data source: Florida Geographic Data Library, GeoPlan, University of Florida (www.fgdl.org).

Map 12. Jacksonville Electric Authority owned parcels

Map 12. Jacksonville Electric Authority owned parcels
Data source: Florida Department of Revenue.

H6. Conclusion

This highlight provides a resource for the public to make important connections about human activities in the basin and how they affect quality of life and the environment. The maps help to visualize the magnitude and complexity of these issues.

Water Quality, Fisheries, Aquatic Life, & Contaminants