Florida Lake Management Society Annual Conference, Naples, Florida, June 4 – 7, 2007
The following pie chart shows that fertilizer use by agriculture and for residential
turfgrass are major sources of nitrate to the Wekiva Basin (26 and respectively), as are septic tanks (22% of total loading). Fertilizer use
total loadings. Anthropogenic
Domestic wastewater loadings are about 90% of
is also a the total.
20 % of total loading, comprises about half of at 10% of the total.
Nitrate loadings to the Wekiva Basin, Partitioned by Source Significant uncertainties are associated with these estimated loadings, and additional research is recommended to reduce these uncertainties. In particular, the portion of the Basin in residential land uses is growing rapidly, yet field data that can be used to estimate the groundwater loading that result from fertilizer use on residential turfgrass is quite limited. A broad scale monitoring effort is recommended to improve estimates of nitrate loading to groundwater from residential land uses. Natural or unattributed 6% Fertilizer - Res 20% Septic Tanks 22% Fertilizer - Ag 26% Domestic Wastew ater 10% Fertilizer - Golf 2% Atmospheric 2% Livestock 6% Potential strategies for reducing loadings were identified and evaluated in Fertilizer - Other 6%
of the Basin,
nitrate loadings in the Basin homeowners and farmers, and
may need septic tank
to be reduced as much and domestic wastewater
as 85%. effluents
Fertilizer use by contribute the bulk
of the loadings. To achieve the Provisional Pollutant Load would represent the primary targets for load reduction. included:
Reduction Goals, these source types Load reduction strategies evaluated
More stringent requirements for domestic wastewater management as promulgated by Florida Department of Environmental Protection in 2006 as Florida Administrative Code 62-600.550; these requirements will be phased in during the next five years
Replacement of conventional septic systems with advanced septic systems;
Replacement of conventional septic systems by expanding the service areas of central sewer systems;
Wider implementation of Best Management Practices for both fertilizer use and irrigation in residential and agricultural land uses.
Florida Department of Health recommended load reduction strategies for septic systems, as summarized above. Florida Department of Agriculture and Consumer Services and UF/IFAS Extension Service are involved in the development and implementation of Best Management Practices for fertilizer use and irrigation. A load reduction scenario was evaluated in which each of these strategies was assumed to be implemented, resulting in a 20% reduction in nitrate loading.
Session 8B – Page 4