88 REPORT OF INVESTIGATIONS No. 50
Nitrate (NO3) .0 ppm Color 8 units Hardness as
CaCO3 5 ppm
The relatively high iron content (.45 ppm) was probably due to iron dissolved from the casing or pump by the water of low pH (5.2). The water from a well (832-101-2) at Christmas in eastern Orange County had an iron content of 4.5 ppm. This high -iron content probably came from the aquifer because the neutral pH of the water, 7.0, indicates that it is not corrosive.
Total mineral content as high as about 500 ppm and- high concentration of some constituents indicate that the water in some wells in the nonartesian aquifer is polluted. The water from a well (822-138-3) in the southwestern part of Orange County had a dissolved mineral content of 530 ppm (estimated from a conductivity measurement). Concentrations of other constituents were potassium, 10 ppm, sulfate, 107 ppm, and nitrate, 173 ppm, which definitely indicates a nearby source of pollution. Use of water containing an excess of about 45 ppm of nitrate for feeding formulas for infants results in metheglobinemia or cyanosis (blue babies) in the infants. The water from some of the shallow wells had as much as 90 units of color.
SECONDARY ARTESIAN AQUIFERS
Several secondary artesian aquifers occur locally within the confining beds of the Hawthorn Formation and less extensively within the formations above the Hawthorn. These aquifers are usually found at depths ranging from about 60 to more than 150 feet below the land surface and are composed of discontinuous shell beds, thin limestone lenses or permeable sand-and-gravel zones. The secondary artesian aquifers are most productive in tthe area east and south of Orlando where they generally yield sufficient water for domestic use. Open-end cased wells can sometimes be constructed in the secondary artesian aquifers, but screens are often necessary to keep sand from the well and to obtain sufficient water.
WATER LEVELS
A continuous record of the water levels of a secondary artesian aquifer have been recorded in a well about 1 mile east of Bithlo