Illinois Administrative Code › Title 77 - PUBLIC HEALTH › Part 920 - WATER WELL CONSTRUCTION CODE › Section 920.40 - Design Factors

Current through Register Vol. 48, No. 28, July 12, 2024
The design of each well shall include the following:
a) Natural Protection. Location of the well
			 shall include use of every natural protection available to promote sanitary
			 conditions.
b) Geologic Formations.
			 The well construction shall be adapted to the geologic formations and
			 groundwater conditions at the site, but shall comply with this Part.
c) Undesirable Geologic Formations.
			 Water-bearing formations shall be excluded by installing casing or a liner and
			 properly sealing when the formations contain undesirable water. When a
			 contaminated formation is to be excluded, the liner shall be grouted in place,
			 in accordance with Section
			 920.90(h),
			 from 10 feet below the bottom of the contaminated formation to at least 10 feet
			 above the top of the contaminated formation. When multiple water-bearing
			 formations of different static water levels are penetrated in the construction
			 of a water well and the lower water-bearing formation has sufficient yield for
			 the water well, the upper water-bearing formations shall be excluded by
			 installing casing or a liner and properly sealing to prevent the dewatering of
			 the upper water-bearing formations.
d) Capacity. The well shall be capable of
			 producing as much of the desired water quantity as the aquifer or aquifers can
			 safely furnish.
e) Durability.
			 Construction methods and materials shall provide a durable well capable of
			 maintaining safe water and protecting the aquifer.
f) Pitless Well Adapters. No well casing
			 shall be cut off or cut into below ground surface except to install a pitless
			 well adapter below the frost level. Pitless well adapters or pitless units
			 installed on plastic well casing shall be pressurized at the point of
			 attachment with the well casing, unless the pitless unit is solvent welded onto
			 the plastic casing and the riser casing of the pitless unit is plastic. Pitless
			 well adapters installed on steel well casing shall be pressurized at the point
			 of attachment with the well casing, unless the pitless unit is threaded or
			 welded onto the well casing. The annular opening between the well casing and
			 the well borehole or any excavation made to install the pitless adapter shall
			 be filled with earth to minimize settling and shall be mounded to provide
			 drainage away from the well. The contractor installing the pitless well adaptor
			 shall be responsible for the installation of the earth backfill. A list of
			 approved pitless well adapters will be periodically updated and a copy of this
			 list may be obtained from the Department.
g) Well Caps. There shall be no openings
			 through the well cap except for a factory-installed vent, air line connection,
			 and power supply wiring unless a proposal is submitted to and approved by the
			 Department. The proposal shall show that any entrance into the well cap is
			 watertight. In addition, well caps shall:
1)
			 Prevent surface water from entering the water supply;
2) Be secured in position;
3) Be removable only with tools;
			 and.
4) Be resistant to weathering
			 and corrosion.