&EPA
United States
Environmental Protection
Agency
Solid Waste And
Emergency Response
(5201 G)
EPA/540/R-95/104
PB95-962936
9200.5-734C
May 1995
SUPERFUND:
Progress at
National
Priority
List Sites
NORTH & SOUTH DAKOTA
1995 UPDATE
Printed on Recycled Paper
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How to Use the NPL Book
'-*•?
-"t-
m
The site fact sheets presented in this book
are comprehensive summaries that cover a
broad range of information. The fact sheets
describe hazardous waste sites on the NPL and
their locations, as well as the conditions
leading to their listing ("Site Description").
The summaries list the types of contaminants
that have been discovered and related threats
to public and ecological health ("Threats and
Contaminants"). "Cleanup Approach" pres-
ents an overview of the cleanup activities
completed, underway, or planned. The fact
sheets conclude with a brief synopsis of how
much progress has been made in protecting
public health and the environment. The
summaries also pinpoint other actions, such as
legal efforts to involve polluters responsible
for site contamination and community con-
cerns.
The fact sheets are arranged in alphabetical
order by site name. Because site cleanup is a
dynamic and gradual process, all site informa-
tion is accurate as of the date shown on the
bottom of each page. Progress is always being
made at NPL sites, and the EPA periodically
will update the site fact sheets to reflect recent
actions. The following two pages show a
generic fact sheet and briefly describe the
information under each section.
How Can You Use
This State Book?
You can use this book to keep informed
about the sites that concern you, particu-
larly ones close to home. The EPA is commit-
ted to involving the public in the decision
making process associated with hazardous
waste cleanup. The Agency solicits input from
area residents in communities affected by
Superfund sites. Citizens are likely to be
affected not only by hazardous site conditions,
but also by the remedies that combat them.
Site cleanups take many forms and can affect
communities in different ways. Local traffic
may be rerouted, residents may be relocated,
temporary water supplies may be necessary.
Definitive information on a site can help
citizens sift through alternatives and make
decisions. To make good choices, you must
know what the threats are and how the EPA
intends to clean up the site. You must under-
stand the cleanup alternatives being proposed
for site cleanup and how residents may be
affected by each one. You also need to have
some idea of how your community intends to
use the site in the future, and you need to know
what the community can realistically expect
once the cleanup is complete.
The EPA wants to develop cleanup methods
that meet community needs, but the Agency
only can take local concerns into account if it
understands what they are. Information must
travel both ways in order for cleanups to be
effective and satisfactory. Please take this
opportunity to learn more, become involved,
and assure that hazardous waste cleanup at
"your" site considers your community's
concerns.
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NPL LISTING HISTORY
Provides the dates when the
site was Proposed, made Final,
and Deleted from the NPL.
SITE RESPONSIBILITY
Identifies the Federal, State,
and/or potentially responsible
parties taking responsibility
for cleanup actions at the site.
ENVIRONMENTAL
PROGRESS
Summarizes the actions to
reduce the threats to nearby
residents and the surrounding
environment and the progress
towards cleaning up the site.
SITE NAME
STATE
EPA ID# ABCOOOOOOO
Site Description
EPA REGION XX
COUNTY NAME
LOCATION
Other Names:
: xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx xxxxxxxxxxxxx :
: xxxxxxxxxx xxxx xxxxxxxx xxxx xx xxxxxxxxx xx xxxxxx xxxxxxxx I
: xxx xxxxxxxxxxxxx xx xxxxxx xxxx xxxxx xxxx x xxx :
XXXXXXX XXX XXX5Cfeft«*XXXXX XXXXX XXXXXX XXXXXXXX XXXXXXXX XXXX XXXXXXXXXX :
xxxxxxxxxxxx xxxxxxxxSc^nn^xxxx xx xxxxxxxxx xxxxx xxxx xxxx xxxxx xxxxxxx xxxxxxxx
xxxxxxxx xxxxxxxxx xxxx xxxx>tai*xxxxx xxxxxxxx xxxxx xxxx xxxxx xxx xxx xxxxxx
XXXXXXXXXXXX XX XXXXXXX XXX XXXXX XjOftW^XJCX XXXXXX XX XXXX XXX XXXXX XXX XXXXX XXX XXXXX
Site Responsibility:
xxxxxx xxx xxxxx ;
xxxxxx xxxxxxxxx xxxxxxxx
xxxxxxxxxxxxx xxxxxxxxx
NPL Listing History
Propoeed- XOTOC/XX
Final XX/XX/XX
Threats and Contaminants
xxxxxx xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx
XXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX
XXXXXXXX XXX XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX
XXX XXXXXXXXXX XXXXXXXX XXXXXXX XXX XXXXXX XXXXXX XXXXX XXXXXX
XXXXXXXX XXXX XXXXXXXXXX XXXXXXXX XXXXXXXXXXXX XXXXXXXXX XXXX X XXX XX
XXXX XXXX XXXXX XXXXXXX XXXXXXXX XXXXXXXX XXXXXXXXX XXXX XX!
xxxxxxxxx
Cleanup Approach
xxxxxx xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx xxxxxxxxxxxxx
XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX XXXXXXXX
XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX X XXX XXXXXXXX
Response Action Status
xxxxxx xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx :
XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX \
XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX X :
XXXXXXXX XXXXXXX XXX XXXXXX XXXXXX XXXXX XXX
XXXXXXXXXX XXXXXXXX XXXXXXXXXXXX XXXXXXXXX XXXX X XXX XX XXXXXXXXX XXXXX XXXX XXXX XXXXX
XXXXXXX XXXXXXXX XXXXXXXX XXXXXXXXX XXXX XXXX XXXXX XXXX XXXXXXXX XXXXX XXXX XXXXX XXX
xxx xxxxxx xxxxxxxxxxxx xx xxxxxxx xxx xxxxxx xx xxxxxx xxxxxxxx xxx :
Site Facts:
xxxxxx xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx
XXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX
XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX X XXX
^^^ttxxxxx ;
Environmental Progress
xxxxxx xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx xxxxxxxxxxxxx xxxxxxxxx
XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX XXXXXXXX XXX
XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX X XXX XXXXXXXXXX
XXXXXXXX XXXXXXX XXX XXXXXX XXXXXX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX
Site Repository
xxxxxx xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx xxxxxxxxxxxxx xxxxxxxxx
SITE REPOSITORY
Lists the location of the primary site repository. The site
repository may include community relations plans, public
meeting announcements and minutes, fact sheets, press
releases, and other site-related documents.
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SITE DESCRIPTION
This section describes the location and history of the site. It includes descrip-
tions of the most recent activities and past actions at the site that have con-
tributed to the contamination. Population estimates, land usages, and nearby
resources give readers background on the local setting surrounding the site.
THREATS AND CONTAMINANTS
The major chemical categories of site contamination are noted, as well as
which environmental resources are affected. Icons representing each of the
affected resources (may include air, groundwater, surface water, soil, and
contamination to environmentally sensitive areas) are included in the margins
of this section. Potential threats to residents and the surrounding environ-
ments arising from the site contamination also are described.
CLEANUP APPROACH
This section contains a brief overview of how the site is being cleaned up.
®
RESPONSE ACTION STATUS
Specific actions that have been accomplished or will be undertaken to clean
up the site are described here. Cleanup activities at NPL sites are divided
into separate phases, depending on the complexity and required actions at the
site. Two major types of cleanup activities often are described: initial,
immediate, or emergency actions to quickly remove or reduce imminent
threats to the community and surrounding areas; and long-term remedial
phases directed at final cleanup at the site. Each stage of the cleanup strategy
is presented in this section of the summary. Icons representing the stage of
the cleanup process (initial actions, site investigations, EPA selection of the
cleanup remedy, engineering design phase, cleanup activities underway, and
completed cleanup) are located in the margin next to each activity descrip-
tion.
SITE FACTS
Additional information on activities and events at the site are included in this
section. Often details on legal or administrative actions taken by the EPA to
achieve site cleanup or other facts pertaining to community involvement with
the site cleanup process are reported here.
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Guide to the NPL Book Icons
The "icons," or symbols, accompanying the text allow the reader to see at a glance which envi-
ronmental resources are affected and the status of cleanup activities at the site.
Icons in the Threats
and Contaminants
Section
Icons in the Response
Action Status Section
Contaminated Ground-water re-
sources in the vicinity or underlying
the site. (Groundwater is often used
as a drinking water source.)
Contaminated Surface Water and
Sediments on or near the site.
(These include lakes, ponds,
streams, and rivers.)
Contaminated Air in the vicinity of
the site. (Air pollution usually is
periodic and involves contaminated
dust particles or hazardous gas
emissions.)
Contaminated Soil and Sludges on
or near the site. (This contamination
category may include bulk or other
surface hazardous wastes found on
the site.)
Threatened or contaminated Envi-
ronmentally Sensitive Areas in the
vicinity of the site. (Examples
include wetlands and coastal areas
or critical habitats.)
Initial, Immediate, or Emergency
Actions have been taken or are
underway to eliminate immediate
threats at the site.
Site Studies at the site to determine
the nature and extent of contamina-
tion are planned or underway.
Remedy Selected indicates that site
investigations have been concluded,
and the EPA has selected a final
cleanup remedy for the site or part
of the site.
Remedy Design means that engi-
neers are preparing specifications
and drawings for the selected
cleanup technologies.
Cleanup Ongoing indicates that the
selected cleanup remedies for the
contaminated site, or part of the site,
currently are underway.
Cleanup Complete shows that all
cleanup goals have been achieved
for the contaminated site or part of
the site.
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EPA ID
Number Site Name
NDD980716963 ARSENIC TRIOXIDE SITE
NDD980959548 MINOT LANDFILL
SDD987666013 ANNIE CREEK MINE TAILINGS
SD2571 924644 ELLSWORTH AIR FORCE BASE
SDD980717136 WHITEWOOD CREEK
SDD000823559 WILLIAMS PIPE LINE CO. DISPOSAL PIT
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ARSENIC
TRIOXIDE
SITE
NORTH DAKOTA
EPA ID# NDD980716963
EPA REGION 8
20 townships in Richland, Ransom,
and Sargent Counties
Site Description
The Arsenic Trioxide Site consists of 20 townships covering approximately 500 square miles of
land. Heavy grasshopper infestations of agricultural crops in the 1930s and 1940s resulted in
widespread and frequent applications of arsenic-based pesticides. In 1979, it was discovered that
the public and private water supplies for the City of Lidgerwood exceeded Federal drinking water
standards for arsenic. Naturally occurring arsenic in shale found in the area also may have
contributed to the contamination problem. Approximately 4,500 people reside in the area. In
1970, the residents of 278 homes in Lidgerwood who used private wells were considered to be at
risk of arsenic exposure. Presently, groundwater is used only for agricultural and domestic
purposes.
Site Responsibility:
The site was addressed through Federal
and State actions.
NPL LISTING HISTORY
Proposed Date: 10/23/81
Final Date: 09/08/83
Threats and Contaminants
The groundwater is contaminated with arsenic as a result of the use of arsenic-based
pesticides. People who drink from private wells in the area could suffer adverse health
effects. Public water supplies in several small cities are being addressed, including the
cities of Lidgerwood, Wyndmere, and Milner.
April 1995
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Cleanup Approach
Response Action Status
Initial Actions: In 1986, 10,000 square feet of contaminated surface area were
covered with clay. Individual water treatment units were installed in 116 private
homes, and five residences were hooked up to a rural water supply system. Also, an
abandoned bait station was cleaned up. In 1988 and 1989, the City of Lidgerwood's water
treatment plant was repaired, and the filter sand was changed.
Rural Areas Water System: Based on the results of the site investigation, the EPA
decided to expand the hookup of homes to the existing rural water treatment and
distribution system in Richland and to evaluate institutional controls on well use and
well drilling. Construction of this phase of the cleanup plan began in the summer of 1990 and
was completed in 1992. The City of Milner was included as part of this phase in 1991. A final
inspection was conducted in the summer of 1993.
Lidgerwood/Wyndmere: Based on the results of the site investigation, the EPA
assisted the City of Lidgerwood with its efforts to improve the water treatment plant.
Construction to improve the Lidgerwood water treatment plant began in 1989 and was
completed in early 1991. In 1990, the City of Lidgerwood, the North Dakota State Department
of Health, and the EPA conducted an inspection of the treatment plant and completed minor
modifications as part of the now completed cleanup activities. The EPA also provided funds to
the City of Wyndmere to increase its water treatment plant's capability to handle periods of high
demand. Site work for the Wyndmere water treatment system was completed in 1991. This
included monitoring of the treatment plant's operating procedures and equipment for one year, in
coordination with the State, to ensure that the treatment plant consistently operated as designed
and produced high quality, colorless drinking water. Treated water is now being pumped to
water users in both cities.
Site Facts: In 1982, a Cooperative Agreement was provided to the North Dakota State
Department of Health to conduct a site investigation. In 1985, the State of North Dakota was
provided a second Cooperative Agreement to conduct an investigation into the nature and extent
of site contamination as well as the most effective methods to clean up the site. Cleanup was
initiated with a Cooperative Agreement to the State hi March 1989.
Environmental Progress
The EPA and the State have installed water treatment facilities and provided waterline hookups to
affected residences. Construction of both city water treatment plants and expansion of hookup to
the rural water system was completed in the fall of 1992, and residents now are provided with
safe drinking water. A 5-year review of the site cleanup will be completed in 1995, after which
the EPA is planning to delete the site from the NPL.
April 1995 2 ARSENIC TRIOXIDE SITE
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MINOT LANDFILL
NORTH DAKOTA
EPA ID# NDD980959541
EPA REGION 8
Ward County
Minot
Site Description
The 15-acre Minot Landfill was operated by the City of Minot from 1962 to 1971. The landfill
received refuse from several nearby industries from 1962 to 1970. While the exact composition
of the disposal materials is not known, available sources indicate that municipal and industrial
wastes, oily wastes, spent battery casings, calcium carbide, lime sludge from acetylene
production, and wastes from the construction of nearby missile sites most likely were disposed of
at the site. Runoff from the site flows toward the Sour is River, a source of drinking water for the
City of Minot, which has a population of approximately 35,000 people. Additional residential and
commercial development has been proposed for the area. The nearest home and business are
approximately 750 feet from the site.
Site Responsibility:
This site is being addressed through
Federal and Municipal actions.
NPL LISTING HISTORY
Proposed Date: 06/24/88
Final Date: 03/24/89
Threats and Contaminants
Hazardous compounds detected in on-site groundwater and landfill gas include benzene
and vinyl chloride. Soils contain chlorinated organic pesticides and inorganic
contaminants. Surface water analysis showed the presence of benzene compounds and
arsenic. Potential risks may exist for individuals who inhale landfill gas or touch or
ingest the contaminated groundwater or leachate. The Sour is River may be threatened
by runoff from the site.
April 1995
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Cleanup Approach
This site is being addressed in two stages: an initial action and a long-term remedial phase
focusing on cleanup of the entire site.
Response Action Status
Initial Action: The City of Minot installed a fence around the landfill to restrict site
access in mid-1990. The City also introduced surface erosion control measures at the
site to halt pesticide and metal contamination from the landfill from seeping to the
surface.
Entire Site: The City of Minot began an investigation at the site in late 1990 to
determine the extent of the contamination and to select a remedy to clean up the
groundwater and areas surrounding the site. The City of Minot completed the
investigation, and a remedy was selected in the summer of 1993. The remedy includes landfill
cap improvements, leachate extraction and treatment, landfill gas collection and dispersion,
groundwater monitoring, and institutional controls. Construction of the remedy has begun and is
scheduled for completion in 1995.
Environmental Progress
The installation of a fence has restricted access to the site and reduced the potential for exposure
to hazardous substances at the Old Minot Landfill site. Surface erosion control measures have
been completed to prevent the possible migration of contaminants to the Souris River while
further cleanup activities are underway.
April 1995 2 MINOT LANDFILL
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ANNIE CREEK
TAILINGS
SOUTH DAKOTA
EPA ID# SDD987666013
EPA REGION 8
Lawrence County
3- 4 miles west of Lead
Site Description
The Annie Creek Mine Tailings site is located hi the Black Hills National Forest, 3l/i miles west
of Lead, South Dakota. The site is situated hi mountainous terrain and wetlands border the entire
length of the Annie Creek corridor. Annie Creek flows southwest down a relatively narrow,
heavily wooded and vegetated valley for approximately 2l/i miles before empty ing into Spearfish
Creek. Spearfish Creek is a fishery and flows northwest through Spearfish Canyon, a National
Scenic Highway and River route. Between 1907 and 1916, gold ore was processed at the mine in
a small cyanide mill. Tailings were disposed of hi an impoundment at the head waters of Annie
Creek, where a timber crib dam was constructed. This impoundment is located approximately 2
miles up Annie Creek above its confluence with Spearfish Creek. Erosion of the arsenic-bearing
tailings from the site over the years has deposited tailings and tailings mixed with soil and
sediment hi Annie Creek and hi the streambed sediments of Spearfish Creek about one mile
below its confluence with Annie Creek. In 1989, the EPA conducted sampling which detected
arsenic contaminated tailings hi Annie and Spearfish Creeks.
Site Responsibility:
This site is being addressed through
Federal and potentially responsibility
parties' actions.
NPL LISTING HISTORY
Proposed Date: 07/29/91
Threats and Contaminants
The soil and sediments in Annie and Spearfish Creeks are contaminated with arsenic.
The surface water and groundwater are contaminated with low levels of arsenic and are
being monitored. Wetlands border the entire length of the Annie Creek corridor.
Ingesting or coming into contact with contaminated soil, sediments, or water may pose
a threat to people and animals.
March 1995
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Cleanup Approach
This site is being addressed in two stages: initial actions and a long-term remedial phase focusing
on cleanup of the entire site.
Response Action Status
• Initial Actions: In early 1994, the EPA covered an exposed area of arsenic-
contaminated mill tailings with clean soil, revegetated the cover, and established
drainage controls to divert surface water runoff from entering Annie Creek. These
activities were completed in the summer of 1994. The institutional controls, scheduled for
completion by late 1995, include deed and access restrictions, land-use limitations, groundwater
use restrictions, surface water and groundwater monitoring, and public information programs.
Entire Site: In mid-1992, the potentially responsible party began an investigation
into the nature and extent of contamination at the site, under EPA supervision. In
1994, the EPA determined that the immediate removal actions described above would
fully address site contamination. No further cleanup actions are planned for the site.
Site Facts: This site is a Superfund pilot project using a cross program multi-media approach
by which the EPA initiated the investigation of the site using the authorities provided by the
federal Clean Water and Safe Drinking Water Acts. The cleanup of the site will continue to meet
requirements of the Superfund program.
Environmental Progress
Initial removal activities have been completed at the site. Institutional controls are scheduled to be
implemented by late 1995. No further cleanup actions are planned at the Annie Creek Mine
Tailings site.
March 1995 2 ANNIE CREEK MINE TAILINGS
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ELLSWORTH
AIR FORCE B
SOUTH DAKOTA
EPA ID# SD2571924644
EPA REGION 8
iMeade and Pennington Counties
miles northeast of Rapid City
Site Description
The 4,858-acre Ellsworth Air Force Base (EAFB) was established in 1942 and is now the 28th
Bombardment Wing of the U.S. Air Force Air Combat Command (ACC), the 44th Strategic
Missile Wing, and the 99th Tactics and Training Wing. Activities at the base generated a variety
of chlorinated solvents, waste oils contaminated with solvents, pesticides, jet fuel, and other
hazardous substances that were disposed of at various areas. A Federal Facilities Agreement
(FFA), negotiated between EAFB, the EPA, and the South Dakota Department of Environment
and Natural Resources (SDDENR), was completed in early 1992. The FFA identifies 12 areas
of the site to be investigated. In 1985, the Air Force initiated investigations at the site that
showed releases of solvents, jet fuel, oil and grease, metals and other hazardous substances to the
soil and groundwater. Approximately 1,600 people obtain drinking water from wells within 3
miles of the site. The nearest surface water intake is located approximately 6,400 feet from the
site.
Site Responsibility:
This site is being addressed through
Federal actions.
NPL LISTING HISTORY
Proposed Date: 10/26/89
Final Date: 08/30/90
Threats and Contaminants
Groundwater, soil, and surface water on site are contaminated with volatile organic
compounds (VOCs), including trichloroethane, methylene chloride, vinyl chloride,
benzene, and xylene, and low concentrations of heavy metals including arsenic and
chromium. Drinking contaminated groundwater and coming into contact with
contaminated soil and surface water could pose health threats.
Cleanup Approach
The site is being addressed in five stages: early actions and four long-term remedial phases
focusing on cleanup of the South Area, the Central Area, the Northern Area, and the
groundwater.
April 1995
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Response Action Status
Early Actions: Contamination of an off-site drinking water well was discovered in
1991. EAFB is providing the affected residents with a permanent alternate water
supply. The Air Force is developing early actions to remove an industrial waste line
pretreatment building, contain contaminated groundwater in the South Area, and remove
contamination from soil at the Fire Protection Training Area, located in the South Area of the
site. The final decision on these projects is scheduled to be made in the spring of 1995, and
construction is expected to begin in early summer. The treatment systems are scheduled to go
into operation by the fall of 1995.
South Area: The South Area consists of four areas which are primarily
contaminated with solvents and jet fuel. Interim cleanup actions will be conducted in
the summer of 1995 for three of the areas; these actions include treating contaminated
soil with soil vapor extraction and installing two groundwater pump and treat systems.
Investigations at the site are scheduled for completion in mid-1996, at which time final cleanup
remedies for the South Area will be selected.
Central Area: The Central Area consists of two areas contaminated with solvents
and jet fuel. The jet fuel-contaminated groundwater is being addressed by the State.
Investigations leading to the selection of final cleanup actions are scheduled for
completion in the fall of 1995 and will address solvent-contaminated groundwater.
Northern Area: The Northern Area has shown low levels of contamination in the
soil and groundwater. Investigations leading to the selection of final cleanup actions
are scheduled for completion in late 1995.
Groundwater: Investigations of the groundwater revealed a large, solvent-
contaminated plume located in the center of the site. An interim cleanup action,
scheduled to begin in 1996, will prevent the groundwater from migrating off site by
installing a collection and treatment system.
Site Facts: EAFB is participating in the Department of Defense (DOD) Installation Restoration
Program (IRP), a specially funded program established by the DOD in 1978 to identify,
investigate, and control the migration of hazardous contaminants at military and other DOD
facilities. A Federal Facility Agreement (FFA) was completed and became effective in April
1992.
Environmental Progress
Supplying drinking water to nearby residents has reduced the threat of exposure to contaminants
from EAFB while the Air Force continues to conduct investigations at the site and develop plans
for cleanup actions.
April 1 995
ELLSWORTH AIR FORCE BASE
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WHITEWOOD
SOUTH DAKOTA
EPA ID# SDD98071713
PA REGION 8
e, Meade, and Butte Counties
Afojlg an 18-mile stretch of the
hitewood Creek flood plain
Site Description
The Whitewood Creek site contains approximately 22 million tons of mining-related wastes such
as mine tailings containing toxic metals. Since the 1870s, millions of tons of mine waste have
been discharged from gold mining operations and deposited along the Whitewood Creek flood
plain. Tailings continued to be discharged to Whitewood Creek until 1977, when the only mine in
the area that still followed this practice built a tailings impoundment for disposal of these wastes.
The EPA has detected arsenic in shallow groundwater in amounts above the State and Federal
drinking water standards. The Whitewood Creek contains low amounts of site-related
contaminants, and local residents use for watering livestock and fishing. Approximately 280
people live within a mile of the site. The site lies adjacent to the town of Whitewood.
Site Responsibility:
This site was addressed through Federal,
State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 10/23/81
Final Date: 09/08/83
Threats and Contaminants
Groundwater, surface water, and soils contained heavy metals including arsenic,
cadmium, chromium, lead, selenium, and cyanide. Soils also were contaminated with
sulfates. People could have been exposed to site-related contaminants by drinking or
touching contaminated groundwater, surface water, or soil. In 1974 and 1975,
approximately 50 Holstein cattle from a dairy operation next to Whitewood Creek died
of unknown causes. Later, a study conducted by the South Dakota State University
showed that the cattle had died of arsenic poisoning, caused by eating corn
contaminated with mining wastes.
April 1995
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Cleanup Approach
Response Action Status
Entire Site: In 1990, the EPA selected a remedy to clean up the site which included:
removing and covering the contaminated soil at the existing residential properties;
continuing the monitoring of White wood Creek surface water quality; and establishing
institutional controls to limit future uses of contaminated areas. The institutional controls involved
continuing the ban on drinking water wells in the 100-year flood plain, establishing zoning
regulations to prohibit development in the tailings deposits areas, and providing an educational
program informing future buyers concerning the condition of the properties within the site area.
The Homestake Mining Company, under EPA and State oversight, conducted the cleanup
activities at the existing residential yards hi the summers of 1991 and 1992. In cleaning up the
yards, Homestake removed a total of 4,500 cubic yards of contaminated soils and disposed of
them at a landfill in an undeveloped portion of the site. Institutional controls in the form of land-
use ordinances were adopted by the three affected counties at the site in 1993 and early 1994.
Homestake has begun long-term monitoring of the water quality of Whitewood Creek. All
construction and cleanup work at the site has now been completed. The EPA began the process
to delete the site from the NPL in late 1994 and expects to complete the process by 1995.
Beginning in 1996, the EPA will conduct 5-year reviews of the site to assess the effectiveness of
the remedy at Whitewood Creek. This assessment may include sampling the soils in residential
yards to ensure that they are not re-contaminated by remaining tailings at the site, reviewing of
the water quality of Whitewood Creek, and reviewing whether or not the county land-use
ordinances are being complied with and enforced.
Site Facts: By 1977, Homestake Mining Company was the only operator continuing to
discharge wastes into Whitewood Creek when other milling operations ceased. In 1982, the
EPA, the South Dakota Department of Water and Natural Resources, and Homestake Mining
Company entered into an agreement to conduct a study of the site. The study investigated the
quality of surface waters, ground water, soils, sediments, and vegetation in the site area and
selected aquatic life of Whitewood Creek. A Consent Decree was signed in 1991, in which
Homestake agreed to pay past cleanup costs incurred by the EPA, conduct remaining cleanup
activities, and to pay any future costs incurred by the EPA or the State.
Environmental Progress
All construction and cleanup work have been completed. Removing contaminated soil,
monitoring Whitewood Creek, establishing institutional controls, and educating nearby site
residents has eliminated the threats posed by the Whitewood Creek site. The EPA will continue
to ensure the effectiveness of the remedies and is in the process of deleting the site from the
NPL.
April 1995 2 WHITEWOOD CREEK
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WILLIAMS PI
COMPANY DISPOSAL
PIT
SOUTH DAKOTA
EPA ID# SDD00082355S
EPA REGION 8
Minnehaha County
Sioux Falls
Site Description
The Williams Pipe Line Company Disposal Pit site lies within the 50-acre 12th Street Terminal
of the Williams Pipe Line Company. The pit was used in the 1970s for disposal of leaded
stillbottoms and storage tank sludge. The facility was an unlined pit where the company disposed
of metals, oily wastes, pesticides, and solvents. The company burned the wastes in the pit
periodically until the 1970s. From 1986 to 1987, the EPA tested the sediments in the pit for
contaminants and determined that they contained volatile organic compounds (VOCs), heavy
metals, pesticides, and poly cyclic aromatic hydrocarbons (PAHs). The EPA found that
groundwater near the pit is contaminated with pesticides and heavy metals. Approximately
33,500 people live within 3 miles of the site. Approximately 100,000 people in the Sioux Falls
area obtain drinking water from two sets of public wells that are within 3 miles of the site. The
site is directly west of a housing development and is 2 miles west of the Big Sioux River and
Skunk River.
Site Responsibility:
This site is being addressed through
Federal, State, and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date: 10/26/89
Final Date: 08/30/90
Threats and Contaminants
Groundwater underlying the disposal pit contains petroleum constituents and arsenic, a
heavy metal. Sediments in the pit are contaminated with various heavy metals, VOCs,
PAHs, and other petroleum-related contaminants. People in the site vicinity who use
or come into direct contact with contaminated groundwater or sediments may be
exposed to hazardous chemicals.
April 1995
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Cleanup Approach
Response Action Status
Entire Site: A study into the nature and extent of contamination at the site began in
1992. In the fall of 1994, the EPA completed investigations and determined that no
further actions were needed since the petroleum contamination was being addressed
under a State order. Potential exposure to arsenic-contaminated groundwater is unlikely;
however, the EPA will conduct monitoring to ensure that the risk from arsenic in the
groundwater remains low. Monitoring will begin in 1995 and will continue for two years.
Site Facts: An Administrative Order was signed by Williams Pipe Line in early 1991, requiring
the company to conduct the site study. An amendment to the Administrative Order was signed in
January 1995 to cover groundwater monitoring. Williams Pipe Line has been conducting a
cleanup of a petroleum release under a State Order.
Environmental Progress
The EPA determined that no federal cleanup activities were necessary at the Williams Pipe Line
Company Disposal Pit. Petroleum contamination is being addressed under a State order, and the
groundwater will be monitored to ensure that arsenic levels remain at low risk levels.
April 1995 2 WILLIAMS PIPE LINE COMPANY DISPOSAL PIT
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