Section 1817.121  Subsidence Control

a)         Measures to prevent or minimize damage.

1)         The permittee shall either adopt measures consistent with known technology which prevent subsidence from causing material damage to the extent technologically and economically feasible, maximize mine stability, and maintain the value and reasonably foreseeable use of surface lands; or adopt mining technology that provides for planned subsidence in a predictable and controlled manner.

2)         Based on the requirements of 62 Ill. Adm. Code 1784.20(b)(7) and (b)(8), the permittee shall perform a survey of the condition of all structures and facilities that may be materially damaged or for which the reasonably foreseeable use may be diminished by subsidence, as well as a survey of the quantity and quality of all drinking, domestic, and residential water supplies within the permit area, subsidence shadow area, and adjacent area that could be contaminated, diminished, or interrupted by subsidence.  The applicant must pay for any technical assessment or engineering evaluation used to determine the pre-mining condition or value of such structures and facilities and the quantity and quality of drinking, domestic, or residential water supplies.  The applicant must provide copies of the survey and any technical assessment or engineering evaluation to the property owner.

A)        The condition survey of structures and facilities shall be performed or scheduled to be performed a minimum of 120 days prior to undermining.  A lesser time may be approved by the Department if justified by the permittee in writing.  The permittee shall provide a copy of the condition survey to the property owner and maintain a copy to be provided to the Department upon request.  The permittee shall provide the Department with verification that the survey has been completed and forwarded to the property owner.

B)        The survey of drinking, domestic and residential water supplies shall be completed and submitted 120 days prior to the water delivery system being undermined.  A lesser time may be approved by the Department if justified by the permittee in writing.  The permittee must provide a copy of the water survey to the property owner and to the Department.

3)         If a permittee employs mining technology that provides for planned subsidence in a predictable and controlled manner, the permittee must take necessary and prudent measures, consistent with the mining method employed, to minimize material damage to the extent technologically and economically feasible to structures and facilities, except that measures required to minimize material damage to such structures are not required if:

A)        The permittee has the written consent of their owners; or

B)        Unless the anticipated damage would constitute a threat to health or safety, the costs of such measures exceed the anticipated costs of repair.

4)         Nothing in this Part prohibits the standard method of room-and-pillar mining.

b)         The permittee shall comply with all provisions of the subsidence control plan prepared pursuant to the requirements of 62 Ill. Adm. Code 1784.20, and as approved by the Department.

c)         Repair of damage.  The requirements of this subsection apply only to subsidence-related damage caused by underground coal extraction conducted after February 1, 1983, except as noted in Section 1817.41(j).

1)         Repair of damage to surface land.  The permittee must correct any material damage resulting from subsidence caused to surface lands, to the extent technologically and economically feasible, by restoring the land to a condition capable of maintaining the value and reasonably foreseeable uses which it was capable of supporting before subsidence damage.

2)         Repair or compensation for damage to structures and facilities.  The permittee must promptly repair or compensate the owner for material damage resulting from subsidence caused to any structure or facility that existed at the time of the coal extraction under or adjacent to the materially damaged structure.  If repair option is selected, the permittee must fully rehabilitate, restore or replace the damaged structure.  If compensation is selected, the permittee must compensate the owner of the damaged structure for the full amount of the decrease in value resulting from the subsidence related damage.  The permittee may provide compensation by the purchase, before mining, of a non-cancelable premium-prepaid insurance policy. 

3)         Adjustment of bond amount for subsidence damage.  When subsidence-related material damage to land, structures or facilities protected under subsections (c)(1) and (c)(2) occurs, or when contamination, diminution, or interruption to a water supply protected under Section 1817.41(j) of this Part occurs, the Department must require the permittee to obtain additional performance bond in the amount of the estimated cost of the repairs if the permittee will be repairing, or in the amount of the decrease in value if the permittee will be compensating the owner, or in the amount of the estimated cost to replace the protected water supply if the permittee will be replacing the water supply, until the repair, compensation, or replacement is completed.  If repair, compensation, or replacement is completed within 90 days after the occurrence of damage, no additional bond is required.  The Department may extend the 90-day time frame, but not to exceed one year, if the permittee demonstrates and the Department finds in writing that subsidence is not complete, that not all probable subsidence-related material damage has occurred to lands or protected structures, or that not all reasonably anticipated changes have occurred affecting the protected water supply, and that therefore it would be unreasonable to complete within 90 days the repair of the subsidence-related material damage to lands or protected structures, or the replacement of protected water supply.  The permittee may also utilize appropriate terms and conditions for liability insurance required under 62 Ill. Adm. Code 1800.60 to assure the financial responsibility to comply with subsection (c) is in place.

d)         Underground mining activities shall not be conducted beneath or adjacent to public buildings and facilities; churches, schools, and hospitals; impoundments with a storage capacity of 20 acre-feet or more or bodies of water with a volume of 20 acre-feet or more, unless the subsidence control plan demonstrates that subsidence will not cause material damage to, or reduce the reasonably foreseeable use of such features or facilities.  If the Department determines that it is necessary in order to minimize the potential for material damage to the features or facilities described above or to any aquifer or body of water that serves as a significant water source for any public water supply system, it may limit the percentage of coal extracted under or adjacent thereto.

e)         If subsidence causes material damage to any of the features or facilities covered by subsection (d), the Department may suspend mining under or adjacent to such features or facilities until the subsidence control plan is modified to ensure prevention of further material damage to such features of facilities.

f)         The Department shall suspend underground mining activities under urbanized areas, cities, towns, and communities, and adjacent to industrial or commercial buildings, major impoundments, or perennial streams, if imminent danger is found to inhabitants of the urbanized areas, cities, towns, or communities.

g)         All underground permittees shall on or before April 1 of each year submit three mine maps of underground workings to the Department.  The mine maps shall indicate the actual extent of mining for the calender year prior to the submittal date.  Mine maps and descriptions shall include the size, configuration, and approximate location of pillars and entries, extraction ratios, measures taken to prevent or minimize subsidence and related damage and areas of full extraction.  The mine maps shall also project the anticipated extent of mining for at least the calendar year at the time of the submittal.  Mine maps shall also include, at a minimum, all features identified in subsection (d), public roads and all Township and Range designations and section corners.  The map shall be sealed by an engineer registered in the State of Illinois.  The maps shall be planned as a continuous map so that areas mined each year may be added and indicated by the dates mining occurred.  Maps shall include the name of the mine and the permittee; address of the permittee; scale, including both written and bar scales; and by whom the map was drawn.  Maps submitted shall be at a scale approved by the Department as necessary to provide sufficient detail for the information required by this subsection.

(Source:  Amended at 29 Ill. Reg. 9829, effective June 27, 2005)