46, Escatawpa River water has average minimum DO levels of 6.0 mg/1 and 

 average maximum DO levels of greater than 12.0 mg/1. BOD levels are 

 generally low. In general the reason for the good water quality of the 

 Escatawpa River is the absence of large industries or population centers in 

 the basin (SARPC 1979). 



Coastal D ra i gages . Waters around Gulf Shores (Pensacola quadrangle) and 

 DaupFTn Island (Biloxi quadrangle) have water-quality problems (coliform 

 bacteria levels) associated with improperly installed or defective septic 

 tank drainfields. Bayou La Batre and Bayou Coden (Biloxi quadrangle) have 

 poor water quality due to waste disposal from seafood industries operating in 

 these areas (SARPC 1979). 



GROUND WATER AVAILABILITY 



The following discussion is taken primarily from Reed and McCain (1971 

 and 1972). There are good quantities of high-quality ground water available 

 throughout Baldwin and Mobile Counties. Ground water in this area is avail- 

 able from permeable sands ranging in age from Eocene to Holocene. These 

 formations can be placed in geologic perspective by referring to the 

 generalized stratigraphic column in the Oil, Gas, and Minerals section of 

 this atlas text. Tables 49 and 50 present data on the geologic series of 

 relevant aquifers, their unit designation, their thickness in both meters and 

 feet, yield, and comments on the general quality of water. 



The principal aquifer in the area is the Miocene-Pliocene aquifer, 

 comprising the Miocene Series and the Citronelle Formation, which is of 

 Pliocene to early Pleistocene age. The structure of the aquifer is complex, 

 the permeable beds of sand interfingering with relatively impermeable lime- 

 stone and clay. The individual beds of permeable sand are usually 15 to 30 m 

 (50 to 100 ft) thick, but reach a thickness of 58 m (190 ft) around 

 Citronelle (Citronelle quadrangle) in Mobile County and 70 m (230 ft) in the 

 vicinity of Loxley (Bay Minette quadrangle) in Baldwin County. The atlas 

 sheets present the contours of the approximate depth (ft) below sea level of 

 the base of the Miocene-Pliocene aquifer capable of yielding as much as 1 mgd 

 per wel 1 . 



Well depths to obtain small quantities of water from the Miocene-Pliocene 

 aquifer range from 46 m (150 ft) deep in the northern portion of the study 

 area to 30 m (100 ft) deep along the coast. These wells generally are 

 capable of delivering at least 3.8 million liters of water per day (mid) (1 

 million gallons of water per day (mgd)). Wells pumping larger quantities of 

 water range in depth from 29 to 244 m (94 to 800 ft) in depth. Water is 

 pumped from these wells at 379 to 3,785 liters per minute (1pm) (100 to 1000 

 gallons per minute gpm)). The specific capacities of these wells are 

 generally between 62 and 435 1pm per meter (5 and 35 gpm per ft) of drawdown. 

 The atlas sheets present the contours of the approximate elevation (feet) 

 above sea level to which water will rise in wells penetrating the Miocene- 

 Pliocene aquifer. 



The Eocene and Oligocene Series are a potential source of water in north- 

 eastern Baldwin County. This formation may produce 1.9 mid (0.5 mgd) per 

 well in nearby Monroe County. 



167 



