Section 920.90  Construction Materials and Other Requirements

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 reject pipe shall not be used.

1)         Steel well casing shall meet one of the following standards:  American Society For Testing Materials (ASTM) A-53-93A or B, A-589-93, or American Petroleum Institute 5L, March, 1982 Edition and conform to the minimum standards given in Table A.

2)         Plastic well casing and liners shall meet the requirements of ASTM Standard F480-94 and the NSF International Standard Number 14-1990, Plastic Piping System Components and Related Materials. Evidence of compliance shall be inclusion in the current  NSF listing and display of the NSF seal on each section of casing, and marking the casing in accordance with the requirements of ASTM Standard F-480-94.

3)         Plastic well casing and liners must be Standard Dimension Ratio (SDR) rated and conform to the minimum requirements given in Table B.

b)         Outer Casing.  Casing intended for construction purposes only shall be of weight and design as 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. 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. Other types of joints may be evaluated and approved by the Department.

d)         Screens.  Screen openings shall provide the maximum amount of open area consistent with strength of 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 inner casing.  A formation packer shall be installed 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 steel nipple 5 to 10 feet long 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:

1)         Grout.  Grout shall be bentonite grout, or neat cement grout as described in Section 920.10.

2)         Application.  When grouting through the inside of the casing, the grouting shall be performed so that the grout fills the annular opening from the bottom to the surface.  When grouting through a tremie pipe that is installed in the annular space, grout shall be pumped through the tremie pipe until grout completely fills the annular space to the surface.  Bentonite, aquajel, or similar materials may be added to the annular opening in the manner indicated for grouting, prior to the cement grouting, to seal any small crevices or fissures and assure that the annular space is open.  If the grout settles below the ground surface or the point of pitless adapter attachment, it is the responsibility of the water well contractor who constructed the well to grout from the depth of settling to the surface or the point of pitless adapter attachment.  If the grout has settled, the annular space shall be grouted as required in Section 920.90(h).  When the grout has settled less than 20 feet, the annular space can be grouted with bentonite chips.

3)         Setting Time.  Drilling operations shall not be resumed until the cement grout has set.  Neat cement grout shall set for at least 48 hours.  Setting time may be reduced from 48 hours by addition of manufacturers' approved chemicals and following manufacturers' recommendations for setting time.  Bentonite grout shall set for a minimum of 1 hour from the start of placement of the grout at the bottom of the annular opening by Tremie Method or 1 hour after completion of grouting by other methods.

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 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 which will not result in contamination of the well. All such water shall be treated so as to maintain a free chlorine residual as an extra precaution.

(Source:  Amended at 24 Ill. Reg. 11934, effective August 1, 2000)