Water Quality Assessment Report - Florida Department of ...

In Citrus County, levels of nitrate exceeding drinking water standards
were detected in numerous wells monitoring large effl uent percolation
ponds. The effect of effl uent on the Homosassa and Chassahowitzka
Spring Complexes is probably insignifi cant, however, because the amount
of nitrogen contributed from effl uent in these ground water basins is low.
In the Weeki Wachee ground water basin, the nitrogen from effl uent is
high, but the treatment plants are dispersed over a very large area and most
are located far from the spring. Also, the low nitrogen isotopic ratios in
the springs indicate an inorganic source, most likely from fertilizer application.
In the Aripeka ground water basin, the nitrogen from effl uent may
contribute some nitrogen to the Aripeka Springs Complex, because the
Hudson wastewater treatment plant is located approximately 3.5 miles
from the spring. However, the plant is probably not the dominant nitrogen
source because, like Weeki Wachee Springs, the low nitrogen isotopic ratios
indicate an inorganic fertilizer source.
Ground Water Usage
Water supply in the Springs Coast Basin is derived principally from the
upper Floridan aquifer. In 1996, ground water use in the basin was estimated
at 80 mgd, or 94 percent of total water use, compared with 5.5 mgd
of surface water. Hernando County accounted for about 45 percent
(38.3 mgd) of total water use, compared with 40 percent for Pasco County
and 15 percent for Citrus County. The largest use of water was for potable
supply (57.9 mgd, or 68 percent). About 30.8 mgd are withdrawn from
within Pasco County for potable supply. The basin contains more than
500 public supply wells, according to the Florida Department of Environmental
Protection’s (Department’s) Public Water System (PWS) Database.
The largest wellfi elds are operated by Hernando County West Utilities
(33 wells), Pinellas County Utilities (31 wells), Hudson Waterworks
(17 wells), and Tampa Bay Water (17 wells).
Public supply constitutes the greatest water use in the basin, with
mining activities a distant second. In addition, 2 wellfi elds in Pasco
County serve as a major source of public water supply for the Tampa Bay
area (which lies outside the basin) through Tampa Bay Water: the Cross
Bar Ranch and North Pasco wellfi elds. Rates of ground water withdrawals
from these facilities in 1996 were 20.2 mgd and 1.6 mgd, respectively.
Most of the area supplying Tampa Bay Water that falls within the Springs
Coast Basin is considered unsuitable for future ground water development.
In some areas, such as Pasco County, wetlands are drying up as a result of
pumping. Large ground water withdrawals in coastal Pasco, Hernando,
and Citrus Counties have also increased saltwater intrusion and the contamination
of water supplies.
In 1998, the SWFWMD conducted a water supply assessment for
4 regions within its boundaries. The majority of the Springs Coast Basin
was contained in the northern water supply planning region, which
includes Citrus, Hernando, and Sumter Counties and portions of Marion,
Levy, and Lake Counties. Water supply demands for the northern region
were projected to grow from 186.4 mgd in 1995 to 246.1 mgd in 2020, an
increase of about 60 mgd (32 percent).
Water Quality Assessment Report: Springs Coast
45