OPEN FILE REPORT NO. 85


Nitrate + Nitrite (NOa, N02) Nitrate and nitrite are both found in spring water in
Florida. Nitrate contamination recently has become a problem in Florida's springs. Nitrate
found in spring water originates from fertilizers, septic tanks and animal waste that enters
the aquifer in the spring recharge area. Nitrate, being a nutrient, encourages algal and
aquatic plant growth in spring water, which may lead to eutrophication of the spring and
associated water body. Nitrite, which is much less of a problem, can originate from sewage
and other organic waste products. When nitrate levels exceed 10 mg/L in drinking water, it
is potentially hazardous to infants, causing methemoglobinemia or "blue baby syndrome".
For this reason, the FDEP has set the Primary Drinking Water Standard for nitrate in
groundwater at 10 mg/L and nitrite at 1 mg/L.

Organic Carbon Natural and non-naturally occurring organic carbon are present in vary-
ing concentrations in spring water in Florida. The primary source of naturally occurring
organic carbon is humic substances (decaying plant material). Synthetic organic represent
a minor component. There are no standards set for naturally occurring organic carbon in
drinking water however, synthetic organic carbon compounds are regulated on an individ-
ual basis in Florida.

Orthophosphate (PO4-3) Phosphate is an essential nutrient and occurs in spring water in
Florida. Unfortunately, an excess of phosphate can cause run-away plant growth and the
eutrophication of surface waters. The Hawthorn Group, a geological unit in Florida, is the
primary source of phosphate in spring water. Other sources include organic and inorganic
fertilizers, animal waste, human waste effluent and industrial waste. In Florida, there is
no regulation nor standard for phosphate.

Potassium (K) Potassium occurs in trace amounts in Florida's spring water and is derived
primarily from sea water. Therefore, it occurs in higher concentration along the coast. The
weathering of feldspars and clays can contribute potassium to spring water. In addition,
because potassium is an essential nutrient, it is a component of fertilizers. In Florida, there
is no standard for potassium and it is considered to be beneficial in moderate concentrations.

Sodium (Na) In Florida, sodium occurring in spring water has several sources. Marine
aerosols, mixing of sea water with fresh water and the weathering of sodium bearing min-
erals like feldspars and clays are the primary sources. The Florida Department of
Environmental Regulation, in 1994, set the maximum allowable concentration of sodium in
drinking water at 160 mg/L. Concentrations exceeding this standard can occur in springs
that discharge from deep Floridan aquifer sources and in coastal areas where spring water
and marine water mixing may occur.

Sulfate (SO4) Sulfate is commonly found in aquifer waters in Florida and has several
sources. The two most common sources are from sea water and the dissolution of gypsum
and anhydrite (naturally occurring rock types within Florida's aquifer systems). Sulfate is
often used as a soil amendment to acidify soils, and thus is associated with agricultural
activities. Finally, disposal and industrial waste activities release sulfate to ground water.
Sulfate rich spring water can potentially be toxic to plants. In higher concentrations it
affects the taste of drinking water. For this reason, the FDEP established a Secondary
Drinking Water standard for sulfate of 250 mg/L.