90 REPORT OF INVESTIGATIONS No. 50
rise that corresponds to general wet or dry periods. This indicates that water enters and leaves the aquifer at a slow rate, and the hydraulic connections to the overlying and underlying aquifers are probably rather poor.
RECHARGE
Recharge to the secondary artesian aquifers in Orange County is by downward leakage from the nonartesian aquifer in most parts of the county and by upward leakage from the Foridan aquifer where the piezometric surface of the Floridan aquifer is above the piezometric surface of the secondary artesian aquifers. A small amount of water probably flows into the county from secondary artesian aquifers in surrounding counties. The secondary artesian aquifers are the least likely to be polluted because the overlying, low-permeability beds tend to protect them from surface pollution, and drainage wells are usually cased through the secondary artesian aquifer zone.
DISCHARGE
Water discharges from the secondary artesian aquifers by downward leakage to the Floridan aquifer, upward leakage to the nonartesian aquifer where the piezometric surface is above the water table, underground flow out of the county, and pumpage.
QUALITY OF WATER
The quality of water in the secondary artesian aquifers in Orange County varies with location, depth, and the local hydrology. In areas where the piezometric surface of the secondary artesian aquifer is below the water table, downward leakage from the water table aquifer occurs and the water tends to be similar to the nonartesian water except where additional solution has taken place within the aquifer. In areas where the piezometric surface of the Floridan aquifer is higher than the piezometric surface of the secondary artesian aquifer, upward leakage occurs from the Floridan aquifer and the water in the secondary aquifer tends to be similar to the water in the Floridan aquifer.
Generally, the dissolved-solids content of the water in the secondary artesian aquifers ranges from 100 to 400 ppm. The predominating ions usually are calcium and bicarbonate. Water from secondary artesian aquifers is sometimes more mineralized than is water from the Floridan aquifer. For example: The water