Illinois Administrative Code
Title 77 - PUBLIC HEALTH
Part 920 - WATER WELL CONSTRUCTION CODE
Section 920.90 - Construction Materials and Other Requirements
Current through Register Vol. 48, No. 12, March 22, 2024
a) Casing and Liner Pipe. In selection of casing and liner pipe, consideration shall be given to the stress to which the pipe will be subjected during construction and the corrosiveness of the water with which it comes in contact. Used or rejected pipe shall not be used.
b) Outer Casing. Casing intended for construction purposes only shall be of weight and design necessary to be watertight and permit installation without distortion or rupture to the specified depth and shall be removed upon completion of the well.
c) Joints. All casing and liner pipe joints shall be watertight. When the water well casing is to be extended, the joint shall be a threaded coupling or welded if the casing is metal, or the joint shall be solvent welded if the casing material is plastic. When plastic well casing is installed, the pipe spigot and socket shall be cleaned and treated with a cleaner primer. Other types of plastic joints may be evaluated and approved by the Department on the basis of NSF/ANSI 14-2010a, NSF/ANSI 61-2010a, and laboratory pressurization tests for leakage. A pressurized connection shall be used when steel casing is used to extend plastic casing when the connection is within 20 feet of the ground surface.
d) Screens. Screen openings shall provide the maximum amount of open area consistent with the strength of the screen and the grading of the water-bearing formation or gravel pack. The openings shall permit maximum transmitting ability without clogging or jamming. Screens shall be made of non-corrosive material.
e) Drive Shoe. Pipe that is to be driven shall be equipped with a drive shoe.
f) Grouting Guides. Casing that is to be pressure grouted in the drill hole or annular opening shall be provided with a centering shoe and shall have sufficient guides or centralizers to permit the unobstructed flow and deposition of the thickness of grout specified.
g) Plastic Casing Installations. There shall be no penetrations through the casing. A formation packer may be installed just above the screen on unconsolidated formation wells or just above the bottom of the casing. A coupling shall be cemented on the bottom of the casing to stabilize it in the hole. A section of steel well casing, a minimum of 5 feet in length and meeting the requirements of subsection (a)(1) may be used on the bottom of the casing in lieu of the coupling. In rock wells, the casing shall be set into the firm rock a minimum of 3 feet to prevent leaking around the end of the casing. In areas where the water is obtained at the rock surface, the casing shall be set just above the rock.
h) Grouting. Procedures and materials for grouting shall be as follows:
i) Plumbness and Alignment. The bore of the hole shall be sufficiently plumb and straight to receive the casing without binding. The casing shall be sufficiently plumb and straight so that it will not interfere with installation and operation of the pump.
j) Construction Water. Water used in the drilling process shall be obtained from a source that will not result in contamination of the well. All of the water shall be treated so as to maintain a free chlorine residual as an extra precaution.
k) Cement Tile for Bored Wells. The minimum wall thickness shall be 2 inches. The minimum strength of the concrete shall be 4,000 pounds per square inch (psi). Before pouring the concrete, #10 gage reinforcement wire mesh with a grid size of 6 inches by 6 inches shall be installed in the concrete casing form. Other concrete tile manufacturing methods shall be approved if they are certified by the manufacturer to withstand loads at depths of 120 feet with a 2:1 load factor. Certification shall be in the form of a letter from a professional or structural engineer registered in Illinois. If the slab is buried, the top of the casing shall not be installed deeper than 30 feet below ground surface. To keep the tiles aligned during installation, the concrete tile shall be formed to have overlapping joints on the top and bottom or another equivalent means of alignment shall be used.
l) Fiberglass Casing for Bored Wells. Fiberglass casing for bored wells shall meet the requirement for NSF/ANSI Standard 61 and be installed no deeper than 120 feet. The manufacturer shall certify that the fiberglass casing can withstand loads at depths of 120 feet with a 2:1 load factor. Certification shall be in the form of a letter from a professional or structural engineer registered in Illinois. If the casing is buried, the top of the casing shall not be installed deeper than 30 feet below ground surface.
m) Buried Slab for Bored Wells. The manufacturer shall certify that the buried slab shall withstand loads at depths to which it will be installed with a 2:1 load factor. Certification shall be in the form of a letter from a professional or structural engineer registered in Illinois. The design, including dimensions and type of reinforcement, shall be submitted to the Department along with the certification letter. The slab shall not be installed before Department approval is issued, based on compliance with this Section.
n) The admission of contaminants to the borehole shall be prevented until the borehole is sealed or finished. For the purpose of this Section, materials and chemicals used to construct the well are not considered contaminants.