Drinking Water & Human Health in Florida
Groundwater is the source of drinking water for 90% of Florida residents. Public water supply use has increased 134% since 1970. Data from over 1,900 wells in Florida's ambient monitoring network indicate generally good water quality, but local groundwater contamination problems exist. Agricultural chemicals, including aldicarb, alachlor, bromacil, simazine, and ethylene dibromide (EDB) have caused local and regional (in the case of EDB) problems. Other threats include petroleum products from leaking underground storage tanks, nitrates from dairy and other livestock operations, fertilizers and pesticides in stormwater runoff, and toxic chemicals in leachate from hazardous waste sites. The state requires periodic testing of all community water systems for 118 toxic organic chemicals.
Potential sources of groundwater contamination are numerous in Florida. The state's unique hydrogeologic features of a thin soil layer, high water table, porous limestone and large quantities of rainfall coupled with rapid population growth, result in a groundwater resource extremely vulnerable to contamination. There are tens of thousands of potential point sources such as surface-water impoundments, drainage wells, underground storage tanks, flowing saline water wells, hazardous wastes sites, power plants, landfills and cattle and dairy feedlots. Similarly there are numerous septic tanks and urban and industrial areas that may discharge water with undesirable quality. Non-point sources that have vast potential for groundwater contamination include coastal saltwater bodies, agricultural and horticultural practices, and mining. Wetlands (10.9 million acres (4.4 Mha)) provide buffers between anthropogenic activities and water quality of lakes, streams, and groundwater. Recognition of the function of wetlands is essential for sustainable development in Florida.
Conditions in Your Watershed
The Environmental Protection Agency provides information on drinking water systems by county. The Florida Department of Environmental Protection (FDEP) Drinking Water Section lists drinking water violations in Florida and the FDEP Source Water Program manages state surface waters.
Data on organic quality of water from the state's principal aquifers are limited; nevertheless, occasional incidences of organic contaminants that may affect human health and welfare are a reality. In the Northwest Florida Water Management District the most prevalent organic contaminants are dry-cleaning solvents and leaking underground gasoline storage tanks. Santa Rosa, Escambia and Holmes counties in the Florida panhandle get their water from the sand and gravel aquifer. This is the sole source for Escambia County. Wells furnishing water for the county populati on are from two to five hundred feet deep. Ten major wells owned by the Escambia County Utility Authority (ECUA) are contaminated. A dry-cleaning solvent (PCE) is the biggest contaminant. Benzene, which indicates petroleum contamination, has also been identified in multiple wells. It is important to point out that rainfall within the boundaries of the county accounts for nearly all the available groundwater. Because of groundwater recharge characteristics, any disposal of waste products or misuse of toxic chemicals on the land surface, whether accidental or intentional, has a high probability for adversely impacting groundwater.
The Biscayne aquifer has been designated by the USEPA as a "sole source" drinking-water supply. The Biscayne aquifer is managed closely to control saltwater intrusion. Water in the aquifer is primarily a calcium bicarbonate type that does not exceed standards for most uses. However, it is subject to contamination by organic solvents used in industry, pesticides and nutrients used in agricultural and urban settings, and leaking fuel storage facilities. Iron concentration in untreated groundwater is commonly larger than the secondary standard of 300 g/L. Iron is commonly associated with the large natural organic content of the region's groundwater resource. This large natural organic content has contributed to the formation of trihalomethanes during chlorination of public water supplies.
The major inorganic constituent of the surficial aquifers is calcium carbonate. Concentrations of dissolved solids are generally less than 1200 mg/L. In the intermediate aquifers, the inorganic chemical composition is generally mixed calcium magnesium carbonate. Water in these aquifers is hard to very hard. Nitrate, fluoride and iron concentrations generally do not exceed drinking-water standards, but sodium, chloride and dissolved solids commonly do. Saltwater intrusion and upward movement of saline water from deeper aquifers commonly result in unsuitable water quality for most uses.
The major inorganic constituent in the Floridan aquifer is calcium carbonate with concentration of dissolved solids less than 500 mg/L. Although the water tends to be hard, it generally does not exceed drinking-water standards for nitrate, fluoride, sodium and chloride. Iron may exceed the standard in about 10% of water-quality analyses.
In predominantly agricultural regions of Florida, the frequency of drinking water wells contaminated by nitrates exceeds the national frequency (2.4%) found in the EPA survey. Of 3949 drinking water wells analyzed for nitrate by the Florida Department of Agriculture and Consumer Services, (FDACS) and the Florida Department of Environmental Protection, 2483 (63%) contained detectable nitrate and 584 wells (15%) contained nitrate above the EPA MCL (maximum contaminant level). Of the 584 wells statewide that exceeded the MCL, 519 were located in the Central Florida Ridge citrus growing region, encompassed primarily by Lake, Polk and Highland Counties.
Determinants of Change
The following factors impact water quality in Florida:
- Population growth (increased waste generation)
- Enforcement of total maximum daily loads (TMDLs)
- Florida Stormwater Rule
- Mandated development and implement minimum flows and levels to maintain riverine base flow to maintain in-stream water quality, fish and wildlife habitats, and estuarine integrity.
- Required use of Best Management Practices and precision application of nutrients, pesticides, and irrigation water.
The University of Florida Cooperative Extension Service and Florida A&M University College of Engineering Sciences, Technology & Agriculture Cooperative Extension and Outreach Program develop and deliver programs designed to provide educational outreach into all counties of the state. Extension education enables research conducted at colleges, universities and other places throughout the world to be interpreted and delivered to the end user (e.g., families, business owners and agricultural producers). Some of the major Extension education programs addressing drinking water and human health in Florida are:
The objective of FL412 Florida's Comprehensive Water Quality Program is to provide educational materials, training and programs, where appropriate, in the areas of water quality assessment, protection and improvement for diverse clientele groups in the state of Florida. It aims to increase public awareness of the options for safeguarding drinking water quality through development and use of Best Management Practices to enhance sustainability and protection of drinking water quality.
Youth development programs in FL714 (1962) FL214 (1890) Environmental Education help individuals understand their interdependence with the environment, local ecosystem, energy and other natural resources. Information that addresses all perspectives of critical issues is presented with emphasis on maintaining the quality of human life as well as the quality of the environment. Individuals can then make informed decisions for remediation of environmental issues with a better understanding of the long and short term consequences of their choices.
Guidelines developed for FL114 Environmental Landscape Management in Florida integrate landscape characteristics of site conditions, landscape design, plant selection and placement, irrigation, fertilization, pest control, mowing, pruning and recycling. Specifically, the Environmental Landscape Management and Florida Yards & Neighborhoods programs teach consumers and other stakeholders how to water efficiently, mulch, recycle yard wastes, manage pests through IPM (Integrated Pest Management), put the right plant in the right spot, fertilize as needed, provide food, water and shelter for wildlife, protect ground water and surface water bodies (i.e., bays, rivers, lakes, ponds, etc.) and minimize stormwater runoff.
The FL269 Water Quality and Environmental Programs in North Florida Design Team teaches small-scale farmers, rural families, public officials, agency representatives, local organizations, community leaders, wholesalers and retailers about practices to enhance the quality of their drinking and domestic water supply. This program is tailored for particular environmental conditions in northern Florida.
The primary impact of FL316 Florida's Coastal Environment and Water Quality program involves increased efforts to apply sustainable management to Florida's coastal and estuarine resources. Increased understanding of ecological, economic and management principles and processes among citizens, professionals and agency personnel is promoted. Citizens become more involved in coastal and estuarine monitoring and management and ecological concepts are more frequently key in discussions held by state and federal management agencies.
- Florida Agricultural Experiment Station, Office of the Dean For Research
- FAMU-CESTA Research Programs
College and University Education
Youth and continuing adult education are critical to develop new talent and human resources to address the water quality issues of the future. Educational curricula in drinking water and human health are available within several colleges at the University of Florida, College of Agriculture and Life Sciences, College of Design, Construction and Planning and College of Natural Resources and Environment. Key courses include those found in the following areas:
- Agricultural and Biological Engineering
- Agricultural Operations Management
- Civil and Coastal Engineering
- Environmental Engineering Sciences
- Forest Resources and Natural Resource Conservation
- Landscape Architecture
- Pest Management – Plant Protection
- Soil and Water Science
Courses addressing drinking water and human health at Florida A&M University are located within the College of Engineering Sciences, Technology & Agriculture.
Related Web Sites
University of Florida
- Soil and Water Science Department
- Department of Agricultural and Biological Engineering
- The Florida Water Resources Primer
- Wetland Biogeochemistry Laboratory
- Florida Farmstead Assessment System (Florida Farm*A*Syst)
- Florida Homestead Assessment System (Florida Home*A*Syst)
- Keep Your Well Water Clean (for adult poor readers)
- Florida Yards & Neighborhoods
Federal and State Agencies
- USDA Natural Resources Conservation Service
- USGS National Water Quality Program
- Florida Department of Environmental Protection
- Florida Department of Agriculture and Consumer Services
- Florida Department of Health and Human Services
- Northwest Florida Water Management District
- Suwannee River Water Management District
- St. Johns River Water Management District
- Southwest Florida Water Management District
- South Florida Water Management District