[Code of Federal Regulations]
[Title 40, Volume 22]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR258.15]

[Page 397-398]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 258--CRITERIA FOR MUNICIPAL SOLID WASTE LANDFILLS--Table of Contents
 
                    Subpart B--Location Restrictions
 
Sec. 258.15  Unstable areas.

    (a) Owners or operators of new MSWLF units, existing MSWLF units, 
and lateral expansions located in an unstable area must demonstrate that 
engineering measures have been incorporated into the MSWLF unit's design 
to ensure that the integrity of the structural components of the MSWLF 
unit will not be disrupted. The owner or operator must place the 
demonstration in the operating record and notify the State Director that 
it has been placed in the operating record. The owner or operator must 
consider the following factors, at a minimum, when determining whether 
an area is unstable:

[[Page 398]]

    (1) On-site or local soil conditions that may result in significant 
differential settling;
    (2) On-site or local geologic or geomorphologic features; and
    (3) On-site or local human-made features or events (both surface and 
subsurface).
    (b) For purposes of this section:
    (1) Unstable area means a location that is susceptible to natural or 
human-induced events or forces capable of impairing the integrity of 
some or all of the landfill structural components responsible for 
preventing releases from a landfill. Unstable areas can include poor 
foundation conditions, areas susceptible to mass movements, and Karst 
terranes.
    (2) Structural components means liners, leachate collection systems, 
final covers, run-on/run-off systems, and any other component used in 
the construction and operation of the MSWLF that is necessary for 
protection of human health and the environment.
    (3) Poor foundation conditions means those areas where features 
exist which indicate that a natural or man-induced event may result in 
inadequate foundation support for the structural components of an MSWLF 
unit.
    (4) Areas susceptible to mass movement means those areas of 
influence (i.e., areas characterized as having an active or substantial 
possibility of mass movement) where the movement of earth material at, 
beneath, or adjacent to the MSWLF unit, because of natural or man-
induced events, results in the downslope transport of soil and rock 
material by means of gravitational influence. Areas of mass movement 
include, but are not limited to, landslides, avalanches, debris slides 
and flows, soil fluction, block sliding, and rock fall.
    (5) Karst terranes means areas where karst topography, with its 
characteristic surface and subterranean features, is developed as the 
result of dissolution of limestone, dolomite, or other soluble rock. 
Characteristic physiographic features present in karst terranes include, 
but are not limited to, sinkholes, sinking streams, caves, large 
springs, and blind valleys.