Water Supply System Description
The City Water Supply is from four groundwater wells, numbered 2, 3, 5, and 6 which are drilled in the sand and gravel aquifier to depths of 72, 79, 75, and 75 feet respectively. These wells are located along Big Creek, East of Marshall. In 2000, wells 2 and 3 were filled with an aqua screen. This is fine gravel type material affixed to a perforated PVC suction pipe for each pump. This screen allows for a more evenly distributed water withdrawal along the full length of the suction pipe. In 2007, Wells 5 and 6 were completed. The raw water is pumped through the new chemical feed building where it is treated with chlorine and flouride before it is dispersed through the parallel 12" PVC mains which flow to town, to the 1967 500,000 gallon water tower located along IL Route 1 just South of Archer Avenue, which is 139’0" to the overflow. When the tower controls gauge that the tower is full the water is routed to the 1995 500,000 gallon water tower located just south of the TRW facility in the southwest part of town. This tower has an overflow height of 110’6". When the tower controls gauge that the tower is full a signal is sent to the pumps at the well site to shut off. The pumps will remain off until the water level in the towers drop to a set point in which a signal will be sent to the wells for a pump to begin pumping. Normally one pump is able to keep up with demand and all four wells are on a daily rotation from being lead pump to being back up and stand by pump. If demand requires, two pumps can be pumped at the same time with a third pump acting as back up. The average water pumpage from the wells is approximately one million gallons per day. This supplies the 2000 city customers.
Water Department Duties
The Water Department has four full time employees, these employees operate and maintain the water wells, take water samples for ILEPA testing, install new water services, maintain existing services and conduct a meter change out program, flush fire hydrants quarterly and replace or extend smaller diameter mains and service lines.