ASTM D8512-23

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D8512 − 23
Standard Practice for
Preliminary Karst Terrain Assessment for Site Development
This standard is issued under the fixed designation D8512; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.4 The use of this practice is limited to the scope as set
forth in this section. However, the report might be of interest
1.1 This practice defines and summarizes various proce-
and useful in endeavors that the site characterization and report
dures for assessing specific sites for potential adverse impacts
do not address. It is beyond the scope of this practice to include
that karst conditions might have on site development including
recommendations to any facet of the project design or con-
proposed construction or site management and impacts to the
struction processes. Any portion of the scope of this practice
resource. Resources impacted may include water quality, water
should be considered carefully if it is found in conflict with
supply, cave, or aquifer fauna, and/or cultural or scientific
local ordinances or regulations. Such a condition may require
resources. Karst impacts to site development include collapse
a formal variance from the issuing agency.
and subsidence, differential subgrade conditions (for example,
shallow bedrock, voids, soft soils, etc.), non-uniform bearing,
1.5 This practice offers an organized collection of informa-
excavation difficulty, and dewatering. The goal is to identify
tion or a series of options and does not recommend a specific
the relevant conditions for consideration in site selection and
course of action. This document cannot replace education or
design. It is intended to offer various courses of actions that
experience and should be used in conjunction with professional
will provide a rational framework for planning and implement-
judgment. Not all aspects of this practice may be applicable in
ing a site characterization program to define potential karst
all circumstances. This ASTM practice is not intended to
conditions that might impact or be impacted by site develop-
represent or replace the standard of care by which the adequacy
ment consideration for site suitability assessment. It is of note
of a given professional service must be judged, nor should this
that the site assessment can use any combination of the
document be applied without consideration of a project’s many
included procedures
unique aspects. The word “Standard” in the title of this
document means only that the document has been approved
1.2 Since the site is in mapped or identified karst terrain,
through the ASTM consensus process.
final ranking of a site will fit in one of the following categories:
(1) There could be minimal karst influence (except subsur-
1.6 Personnel not having specialized training or experience
face influence) on site use and development;
in karst survey and assessment methods should solicit assis-
(2) It is likely that karst will influence or there is future
tance from qualified professionals. All references in this
potential that karst will influence site development;
standard to the “qualified professional” refers to individuals
(3) Karst will play a significant role on future planning and
(such as engineers, soil scientists, geophysicists, geologists
development at the site.
including engineering geologists or hydrogeologists), who
have the appropriate experience and, if required by local
1.3 Objectives guiding the development of this practice are:
regulations, applicable certification, licensure or registration.
(1) to synthesize and put in writing customary practice for
preliminary karst assessments, The term “engineering” must be understood to be associated
with the practices or activities of that qualified professional.
(2) to facilitate high quality, standardized preliminary karst
assessments, and
1.7 This standard does not purport to address all of the
(3) to clarify an industry standard practice for preliminary
safety concerns, if any, associated with its use. It is the
karst assessments to provide a protocol for these assessments
responsibility of the user of this standard to establish appro-
to assist design professionals, plan reviewers, public works
priate safety, health, and environmental practices and deter-
officials, and jurisdictional regulators in making an informed
mine the applicability of regulatory limitations prior to use.
judgment on site development and management.
1.8 This international standard was developed in accor-
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
This test method is under the jurisdiction of ASTM Committee D18 on Soil and
Development of International Standards, Guides and Recom-
Rock and is the direct responsibility of Subcommittee D18.27 on Karst.
mendations issued by the World Trade Organization Technical
Current edition approved Nov. 1, 2023. Published December 2023. DOI:
10.1520/D8512-23 Barriers to Trade (TBT) Committee.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8512 − 23
2. Referenced Documents sinkhole) that recharge an aquifer, as opposed to a losing
2 stream which loses its flow over an extended distance.
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained
4. Summary of Practice
Fluids
4.1 As described by Denton (1) and Veni (2), procedures of
D5717 Guide for Design of Ground-Water Monitoring Sys-
assessment will generally fit into two broad areas:
tems in Karst and Fractured-Rock Aquifers (Withdrawn
(1) A desktop review of available information such as
2005)
digital elevation models (DEMs), Light Detection and Ranging
D6429 Guide for Selecting Surface Geophysical Methods
(LiDAR), satellite imagery, topographic maps, aerial photos,
and reports of known karst conditions;
3. Terminology
(2) Site field reconnaissance.
3.1 Definitions—For definitions of common technical terms
used in this standard, refer to Terminology D653.
5. Significance and Use
3.2 Definitions of Terms Specific to This Standard:
5.1 This practice may serve to assist qualified professionals
3.2.1 cave, n—a natural underground space large enough for
in conducting preliminary karst assessments, and helping
a person to enter and may have a connection to the surface.
design professionals, plan reviewers, public works officials,
3.2.2 closed depression, n—an enclosed topographic low in and jurisdictional regulators in determining the minimum
elements that should be expected in a site evaluation. It should
the land which may be of natural or anthropogenic origin. (See
also sinkhole.) be emphasized that the protocol presented herein is not
intended to serve as a substitute for detailed subsurface
3.2.3 conduit, n—a void that transmits or has the capacity to
investigations, or to supersede any existing karst regulations or
transmit turbulently flowing water in karst, which occurs when
codified protocols.
the void achieves a width of about 1 cm and used generally to
describe all segments of karst drainage networks or to refer
5.2 According to Gutiérrez et al. (3) it is important to
specifically to segments too small for human entry. Conduits
understand that geo-hazards in karst terrain differ considerably
large enough for human entry are called caves.
from other natural settings. These geo-hazards are exacerbated
by the redirection and concentration of water draining into the
3.2.4 covered karst, n—a karst area where a great majority
subsurface and removal of soil or other natural cover over karst
of the karstic bedrock is below a thick deposit of soil, alluvium,
openings. The karst system is often unable to manage the
or sedimentary material; also known as mantled karst.
effects of heavy rainfall and flash floods, resulting in the
3.2.5 karst, n—a terrain with distinctive hydrology and
formation and/or reactivation of sinkholes, soil subsidence or
landforms that arise from a combination of rock solubility and
slope movement, and these effects become exaggerated by
well developed porosity and permeability.
human alteration of the natural drainage. In addition, the lack
3.2.6 paleokarst—karst phenomenon that have been formed
of filtration inherent to karst hydrogeologic systems can result
during the Tertiary or before and refers to karst features that
in transport and migration of a diverse variety of water-borne
have been preserved in the rock mass.
contaminants, including but not limited to pathogens, heavy
3.2.6.1 Discussion—These preserved features are often
metals, sediments, free-product, and dissolved-phase
masked but their presence can be inferred. This process
chemicals, as well as residual-phase contaminants adsorbed on
requires detailed understanding of geological processes, an-
sediment. The removal of cover by grading will reduce support
cient landscapes and geological events that took place at the
over cavities in the subsurface and increase the potential for
site of interest.
collapse or subsidence, particularly where surface water con-
3.2.7 pinnacle, n—bedrock remnant between solutionally centration occurs.
enlarged fractures where the remnant height is usually substan-
6. Procedure
tially greater than its width and at a scale typically less than 30
m in height; common usage implies a surface feature, but it
6.1 Desktop Review:
may be fully or partly covered by soil or sediment.
6.1.1 Site Description and Terrain Analysis—Describe the
site, based on examination of the most detailed topographic
3.2.8 sinkhole, n—a naturally formed topographically
mapping available and subsequent field observations. More
closed depression in the surface of the Earth formed by
detailed LiDAR can be used if available. LiDAR data can be
solution of bedrock and/or collapse or subsidence of bedrock or
used to create digital elevation models (DEMs) and topo-
overlying soils or sediment.
graphic maps if practicable, to examine the site for the
3.2.9 sinking stream, n—a stream that loses all or most of its
presence of closed descending contours suggesting the pres-
flow into a feature or group of features (typically a cave or
ence of a sinkhole or closed depression. In addition, stereo-
scopic aerial photograph pairs and aerial photo fracture trace
analysis may be used. Note any karst features (that is, caves
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
entrances, sinkholes, closed depressions, etc.) visible on the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3 4
The last approved version of this historical standard is referenced on The boldface numbers in parentheses refer to a list of references at the end of
www.astm.org. this standard.
D8512 − 23
topographic map and remote sensing resources. Note the surface, breccia pipes and paleokarst will seldom cause prob-
presence of any water features on the site and directions and lems beyond those presented by typical karst features.
pathways for site drainage and surface water flow. Include a However, when encountered in the subsurface (for example,
careful delineation of the property’s metes and bounds in the during mining and/or tunneling) these features can be, and
have been, life threatening. As with most adverse construction
site description, and its current use and condition (that is,
vacant land, agricultural land, developed land and alike). conditions, early recognition and avoidance is the most effec-
tive way to mitigate potential problems. However, breccia
6.1.2 Description of Soils and Bedrock Geology—Access
pipes and paleokarst terrain susceptible to subsidence and
soil maps for the project site. Examine soils data for the site
sinkhole formation can be widespread in some areas.
and adjacent properties, with particular emphasis on the parent
Therefore, according to Fischer and McWhorter (5) mitigation
materials (that is, whether the soils are residual or transported),
methods (for example, reverse graded filters, transit-mix plugs,
their hydrologic characteristics, and textural analysis. Soils in
various types of grouting, dynamic compaction, special foun-
certain geological settings may be noted as being “prone to
dation designs such as piles, and careful drainage design to
sinkhole formation” in soils maps. These soils shall be noted
keep water away from karst features) should be used to
and indicated in the final report.
minimize the impact of reactivated paleokarst.
6.1.2.1 Understanding the soils in conjunction with the
6.1.3 Description of Surface Drainage and Water
underlying bedrock is critical to predicting whether sinkholes
Features—Evaluate the surface drainage patterns at the site by
will form after a site has been cleared of vegetation. Where
examination of the topography. Identify limits of the drainage
surficial soils obscure the top of rock, covered or mantled karst
basin and primary discharge points into major waterbodies.
condition may exist where numerous soil-filled or open con-
Conduct research for publicly available hydrological assess-
duits may be present beneath a seemingly homogeneous soil
ments that may have been performed for the region by
cover. Upon removal of the vegetation and topsoil during
governmental or other entities.
stripping operations, infiltration will increase and the cover
6.1.3.1 The analysis of drainage patterns shall determine if
over expanding subsurface cavities is reduced to the point of
the site has outlets (that is, if drainage is directed offsite) or if
collapse, or the soil may begin to ravel due the surface
it is internally drained as these factors can profoundly affect
infiltration into covered subsurface voids or conduits and
site planning, especially in regard to stormwater management.
sinkholes may form.
Drainage to sinkholes shall be clearly delineated.
6.1.2.2 Research bedrock geology by referencing the high-
6.1.3.2 The locations of springs, streams, and water bodies
est resolution geological mapping available. This information
(lakes, ponds, wetlands, etc.) shall be noted. The locations of
often can be found by accessing the websites of the local or
losing streams, gaining streams, and sinking streams shall be
regional geological survey and water resources agencies. Note
carefully noted where these conditions can be identified. Note
dip and strike of the bedrock, and any significant structural
any discontinuous drainage ways and disappearing streams. It
features (mapped faults, anticlines, synclines, etc.). It is often
can be helpful to review historical maps to evaluate whether
of value to examine geologic maps contained in water resource
there have been changes in the site drainage over time. Such
reports as well as mining and minerals maps that would reflect
changes may be reflective of karst activity or alter the risk of
the presence of carbonate rock resources, quarries, and mines
areas where drainage has recently been directed. If such
in the site vicinity. Bedrock will be considered “soluble” if its
conditions are observed, they shall be noted.
lithology consists of a significantly soluble mineralogical
6.1.4 Identification of Previously Inventoried Karst
component (for example, carbonate or evaporite), though
Features—Prior to the field observation phase of the
solubility is often less important than the magnitude and nature
assessment, access available karst and cave survey databases to
of prior dissolution. In highly soluble evaporites, ongoing
determine which, if any, features have been previously located
dissolution of rock can be a significant factor in assessing risk
or mapped at the site or on adjacent areas. The International
to development but is not typically a concern in many
Union of Speleology (www.uis-speleo.org) provides links to
limestones and dolomites. It is of note that in some unconsoli-
national organizations that include such databases for their
dated siliciclastic units the dissolution of accessory carbonate
countries.
fossils (for example, molluscan and bryozoan beds) and thin
carbonate beds can cause surficial deformation karst issues if
6.1.4.1 In addition, many agencies in karst areas maintain
close enough to the land surface or create small preferential inventory maps of karst features such as caves, closed
hydrologic changes at depth which may be counter to the
depressions, sinkholes, etc. Some agencies also publish karst
regional hydrogeology. risk maps and other karst related data. The investigator shall
investigate the availability of such maps and review them as
6.1.2.3 Finally, in some settings, insoluble bedrock may
part of the desktop review. In evaluating any prior database or
overlie karst-forming rock below and surface depressions,
mapping, note the effective dates, basis, authors, and limita-
sinkholes and cave entrances may form when the insoluble
tions of the mapping.
overlying bedrock collapses into cavernous voids beneath.
Therefore, in any setting where this stratification is present, the 6.1.5 Aerial Imagery—Aerial imagery provides a useful
insoluble overlying unit shall be examined for the presence of source of information. In developed areas being considered for
documented sinkholes, depressions, or cave entrances. This is redevelopment, review of historical aerial images that predate
particularly important in regions where paleokarst is present. development may enable identifying karst features that have
As discussed by Lund, et al. (4) when exposed on or near the been obscured by regrading. Aerial imagery is available from
D8512 − 23
multiple sources including data search companies commonly (2) Evidence of anthropogenic activity surrounding the CD
used for environmental assessment, geological survey including human placed features and structures, foreign mate-
rials (concrete, steel, etc.), linear and orthogonal contours, etc.
agencies, regional and local governments, among others.
(3) Evidence of active erosion at the CD.
Google Earth provides free access to a limited amount of
(4) Tension cracks or faulting around the CD.
global aerial imagery, including historical imagery for some
(5) Presence and type of exposed bedrock, if applicable.
locations. Depending on the size, scope, and sensitivity of a
(6) Vegetation in the CD (grass, brush, mature trees, and
project, it may be advantageous to acquire aerial or satellite
the like) and size and estimated ages of trees present.
imagery from specialist companies.
(7) Description of the CD geometry including the presence
6.1.5.1 Examine imagery for isolated brush or trees in
of a “throat” or opening(s) leading into the subsurface, where
plowed fields, trash mounds within open fields, disappearing
present.
streams, pinnacle outcrops, pond areas, intermittent road
(8) Evidence of flooding in and around the CD (water
reroutes, etc. Evidence of karst repairs may include patched
marks, flotsam, saturated soils, outflow channel, and the like).
pavements, collapsed structures, and capped areas. Isolated
(9) Catchment area of the CD including estimated drainage
areas of distinctly different vegetation, or darker/greener veg-
area flowing into the CD.
etation may be indicative of surface depressions, subsidence, or
6.2.1.1 Collect the coordinates from the perimeter of the CD
areas of surface water concentration. Make note of any features
...