Location and Construction of New Private Wells

The first step in providing a safe water supply is to properly locate and construct your new well. Proper location is critical, as the possibility of contamination can be found throughout numerous sources. One of the most important things to consider in providing a good location for your well is to find high ground, thus, making sure surface water drains away from the well and all possible surface contamination sources are at a lower elevation than your well. A well must be no closer than 10 feet to sewers with water tight joints (e.g., schedule 40 PVC pipe or heavier with solvent welded water tight joints); 50 feet to septic tanks and barnyard or animal confinement lots; and 75 feet to septic fields and manure piles.

• Bored wells are constructed in areas where aquifers (a water-bearing geological formation or structure that stores or transmits water to wells and springs) are shallow and low-yielding. Thus, they typically range in depth from 30 to 100 feet. Bored wells have a larger diameter to serve as storage reservoirs to help compensate for low-yielding aquifers. However, this can create a greater potential for contamination. To identify this type of well look for a relatively large stone or concrete object sticking out of the ground or a 5-6 inch riser pipe for bored wells that are constructed by the buried slab method. For information regarding large diameter bored wells, and directions on how to disinfect them, visit IDPH's online fact sheet, Bored Wells.
• Drilled wells normally have narrower holes (4 to 10 inches around) and are deeper; ranging in depth from less than 100 feet to more than 1,000 feet. They can be identified by a pipe, ranging 4 to 10 inches in diameter, sticking about 8 to 12 inches out from the ground with a flat or rounded cover on top. For information regarding small diameter drilled wells, and directions on how to disinfect them, visit the IDPH's online fact sheet, Drilled Wells.
• To learn about the different options and concerns of a new well, visit the University of Illinois Extension's online publication, Planning Your Well: Guidelines for Safe Dependable Drinking Water (13 pages, pdf).
• For more information on specific construction and installation codes for Illinois, visit IDPH's web page, Water Wells.