SYMPOSIUM ON SANITATION 45 



THE EXrERIEXCE OF THE STATE OF ILLIXOIS 

 WITH THE SHALL(3\V WELL. 



EDWARD BARTOW 



\'ery few Illinois cities obtain their municipal water sup- 

 plies from shallow wells. Many people in cities either from 

 necessity or preference use shallow well water for drinking 

 purposes. Cftentimes the city mains are not extended to new 

 sections. Oftentimes in old sections the houses are not con- 

 nected with the mains, making the use of a shallow well neces- 

 sary. Cftentimes the city water furnished has unpleasant 

 physical characteristics like taste, color, or turbidity causing 

 ipeople to prefer the clean shallow well water. 



Tn a great measure the relative use of shallow wells in 

 different sections of the state is dependent upon the source 

 and character of the municipal water supplies. In the north- 

 ern part of the State of Illinois, the majority of the city water 

 supplies are obtained from deep rock wells. In the east cen- 

 tral portion of the state the water supplies are obtained from 

 deep drift wells, in the west central and southern part of the 

 state from streams- It is possible to have deep rock wells in 

 the northern part of the state because the St. Peter and 

 Potsdam sandstones which outcrop in the central and 

 northern part of Wisconsin dip to the southward so that they 

 are from a few hundred feet to two thousand feet 

 below the surface in the northern third of Illinois. 

 or rather north of a line drawn from Ouincy to Chicago. 

 Tiiecause the height above sea level in Illinois is less than in 

 Wisconsin, wells which enter these two strata are free flow- 

 ing or can be easily pumped. Such wells furnish an ideal 

 water for municipal water supply. As the water lies in the 

 water bearing stratum it is absolutely free from contamina- 

 tion. Proper measures must be taken to prevent contamina- 

 tion during delivery to the consumer from defective casing, 

 from contaminated reservoirs, or from faulty connections with 

 river supplies. 



In deep rock wells along or south of a line drawn from 

 Ouincy to Chicago there is a strong probability that the water 

 will be very highly mineralized. It is therefore necessary in 

 the central and southern parts of the state to obtain water 

 supplies from sources other than deep wells in rock. In the 

 eastern part of the central area the glacial drift is deep enough 

 and contains gravel coarse enough to furnish a satisfactory 



