638 THE ILLINOIS GLACIAL LOBE. 



At the villag'e of Utica many artesian wells have been obtained in the 

 Lower Magnesian limestone. The strongest wells are obtained at depths 

 of 215 to 330 feet, but many are of much less depth. The water rises to a 

 height of about 50 feet above the surface, or 525 feet above tide. The 

 strongest wells have an estimated capacity of about 150 gallons a minute, 

 or 200,000 gallons a day. 



The city of Ottawa formerly obtained much of its public water supply 

 from shallow wells piped to a reservoir on the south bluff of the river and 

 distributed by gravity to the city. It is now supplied from six artesian 

 wells and Fox River. A large number of private artesian wells are sunk 

 through the St. Peter sandstone to the underlying strata, from which an 

 excellent quality of water overflows. It is estimated that there are not 

 less than 200 such wells in the city and vicinity. The great majority are 

 but 300 to 400 feet in depth. One boring was sunk, however, to a depth 

 of 1,840 feet and obtained water from the Potsdam, which has a strong 

 flow in the lower 200 feet. The head is estimated to reach 175 feet above 

 the well mouth, or 705 feet above tide The quality of the water is vari- 

 able in the several wells, but is usually slightly sulphurous and moderately 

 hard. The salinity is very slight. 



At the village of Marseilles a large number of private artesian wells 

 have been sunk which obtain water from the St. Peter sandstone at depths 

 of 100 to 200 feet. The head is remarkably low, being but 12 to 20 feet 

 above the surface, or scarcely 500 feet above tide. The wells are ordi- 

 narily but 2 inches in diameter, with a nozzle 1 inch in diameter. Their 

 rate of flow has appreciably decreased within the past 15 years and at pres- 

 ent an average Avell will discharge but 4 or 5 gallons a minute. For fire 

 purposes the village has a system of waterworks which pumps its supply 

 from the Illinois River. 



The village of Seneca, situated in the Illinois Valley near the east 

 border of the county, is also supplied with several private artesian wells, 

 which obtain water from the St. Peter or lower strata at depths ranging 

 from 350 to 680 feet. The strongest flow is thought to be obtained at a 

 depth of about 630 feet. The water is slightly sulphurous, but is other- 

 wise of pleasant taste. The head, like that of the wells at Marseilles, is 

 remarkably low, being scarcely more than 20 feet above the surface at the 

 wells, or 525 feet above tide. 



