Table 49. Summary of geologic units, and availability and quality of ground 

 water in Baldwin County (modified from O'Neil and Mettee 1982). 



Thickness " 



Series 



Geologic unit 



m (ft) 



Avail abil ity of water 



Qual ity of water 



Holocene 



and 

 Pleistocene 



PI iocene 



Miocene 



Alluvium low 

 terrace, and coast- 

 al deposits 



High-terrace 

 deposits 



Citronel le 

 Formation 



Miocene Series 

 undi fferentiated 



Will yield 38 1pm (10 

 gpm) where saturated 

 sands are of sufficient 

 0-46 (0-150) thickness. Potential 



sources of 1,325 to 2,650 

 lpm (350 to 700 gpm) well 

 in the Mobi le basin . 



Probably of good chemical quality 

 in north half of county 

 but locally may have a dissolved 

 solids content that exceeds 

 1,000 mg/1 and may contain objec- 

 tional amounts of iron. In south 

 half of county adjacent to major 

 waterways, water commonly contains 

 objectionable amounts of iron, is 

 very hard, and has a sulfurous 

 odor. Locally, in areas adjacent 

 to the coastline, the water is 

 highly mineral ized. 



0-9 (0-30) 



0-40 (0-130) 



30-900 

 (100-3,000) 



Will yield 38 lpm 

 ( 10 gpm) where satu- 

 rated sands are of suffi- 

 cient thickness. 



Will yield 2,650 lpm 

 (700 gpm) or more 

 per well . 



Water probably is of good chemi- 

 cal quality; locally it may con- 

 tain objectionable amounts of 

 iron. 



Water generally is "of goocf qua! i ty 

 being soft and low in dissolved 

 solids. Locally, the water con- 

 tains objectionable amounts of 

 iron and generally is acidic. In 

 some areas adjacent to the coast- 

 line and in the Mobile River basin 

 the water has a dissol ved-sol ids 

 content that exceeds 1,000 mg/1, a 

 chloride content that exceeds 500 

 mg/1, and a sulfurous odor. 



01 igocene 



Eocene 



Eocene and 

 01 igocene 

 Series 



30-152 

 (100-500) 



120-210 

 (400-700) 



Water may be of good chemical 

 Potential source of quality in northernmost part of 



1,325 lpm (350 gpm) the county near Little River, 



per well. Dissol ved-sol ids content exceeds 



1,000 mg/1 in all other parts of 



the county. 



Wherever the permeable sand and gravel are of sufficient thickness, the 

 alluvium and low terrace deposits of Holocene age are a potential source of 

 groundwater along the Mobile River basin. These deposits may be as thick as 



46 m (150 ft) and yield 1.9 to 

 pumping large quantities of water 

 to 45 m (89 to 148 ft) in depth, 

 and have specific capacities of 

 foot) of drawdown. 



3.8 mid (0.5 to 1.0 mgd) per well. Wells 

 from these deposits generally range from 27 

 produce 1,779 to 3,202 lpm (470 to 846 gpm) 

 75 to 907 lpm per meter (6 to 73 gpm per 



Many industries in the Mobile area are supplied by wells in alluvial 

 deposits. These wells reportedly produce 38 to 5,678 lpm (10 to 1,500 gpm) 

 with specific capacities ranging from 75 to 807 lpm per meter (6 to 65 gpm 

 per foot) of drawdown, production varying more upon the industries' needs 

 rather than the ultimate well capacity. 



168 



