it is unstable and does not generally occur in significant levels (Phelps, 2004). Nitrate in drinking

water is typically measured in terms of the amount of nitrogen (not including oxygen); the

federal standard for nitrate in drinking water is 10 mg/L nitrate-N.

 Nitrate in groundwater not only causes ecological problems but can be a serious threat to

public health. Short-term exposure to drinking water with a nitrate level at or above the health

standard of 10 mg/L nitrate-N is a potential health problem primarily for infants and the elderly,

leading to a disease called methemoglobinemia. Methemoglobin is formed when nitrite oxidizes

the ferrous iron in hemoglobin to the ferric form which means that it cannot bind oxygen (Fan et

al. 1987). Infants consume large quantities of water relative to their body weight and their

immature digestive systems are more likely than adults' to allow the reduction of nitrate to nitrite

(Pierzynski et al, 1994).

 Identifying and quantifying the sources of nitrate pollution within the springshed is the first

step in developing proper management practices and legal framework to protect the water quality

of Florida's springs (Katz, 1999). The definition of a springshed was developed by

Hydrogeology Consortium in 2002 and is stated as "those areas within groundwater and surface-

water basins that contribute to the discharge of the spring" (Upchurch and Champion, 2002).

This definition is important because it includes surface-water drainage basins, such as Rose

Creek and Alligator Lake that discharge into the Ichetucknee's groundwater basin via sinkholes,

swallets, and sinking streams. Contaminants in surface water run-off ultimately end up in the

Ichetucknee and could be significant sources of pollution in the springs. Therefore to gain an

understanding of the level of nutrient pollution in a spring one must account for all of the sources

in the entire springshed, a process referred to as nutrient budgeting.