Solid Waste And
Emergency Response
(5102 G)
SUPERFUND:
EPA/540/R-93/006
December 1992
PB93-963207
Progress at
National
Priority
List Sites
COLORADO
1992 UPDATE
Printed on Recycled Paper
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If you wish to purchase copies of any additional State volumes, contact:
National Technical Information Service (NTIS)
U.S. Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
(703) 486-4650
The complete set of the 49 State reports may be ordered as PB93-963250.
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TABLE OF CONTENTS
INTRODUCTION
A Brief Overview of Superfund v
Streamlining Superfund: The Superfund Accelerated Cleanup Model ix
How Superfund Works x
THE VOLUME
How to Use the State Book xi
A SUMMARY OF THE STATE PROGRAM
.XV
THE NPL REPORT
Progress to Date xix
THE NPL FACT SHEETS i
THE GLOSSARY
Terms used in the NPL Book G-l
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INTRODUCTION
A BRIEF OVERVIEW OF SUPERFUND
During the second half of the Twentieth
Century, the environmental conse-
quences of more than 100 years of industrial-
ization in the United States became increas-
ingly clear. Authors such as Rachel Carson
wrote passionately about the often-hidden en-
vironmental effects of our modern society's
widespread use of chemicals and other, haz-
ardous materials. Their audience was small at
first, but gradually their message spread.
Growing concern turned to action, as people
learned more about the environment and be-
gan to act on their knowledge
The 1970s saw environmental issues burst
onto the national scene and take hold in the
national consciousness. The first Earth Day
was observed in 1970, the year that the U.S.
Environmental Protection Agency (EPA) was
founded. By the end of the 1970s, Love Canal
in New York and the Valley of the Drumis in
Kentucky had entered the popular lexicon as,
synonyms for pollution and environmental
degradation.
Superfund Is Established
The industrialization that gave Americans the
world's highest standard of living also created
problems that only a national program could
address. By 1980, the U.S. Congress had
passed numerous environmental laws, imple-
mented by the EPA, but many serious hazard-
ous waste problems were slipping through the
cracks.
Responding to growing concern about public
health and environmental threats from uncon-
trolled releases of hazardous materials, the
U.S. Congress passed the Comprehensive En-
vironmental Response, Compensation, and
Liability Act (CERCLA). Popularly known as
Superfund, CERCLA had one seemingly
simple job—to uncover and clean up hazard-
ous materials spills and contaminated sites.
A Big Job
Few in Congress, the EPA, the environmen-
tal community, or the general public knew in
1980 just how big the nation's hazardous ma-
terials problem is. Almost everyone thought
that Superfund would be a short-lived pro-
gram requiring relatively few resources to
clean up at most a few hundred sites. They
were quite mistaken.
As the EPA set to work finding sites and.
gauging their potential to harm people and
the environment, the number of sites grew.
Each discovery seemed to lead to another,
and today almost 36,000 hazardous waste -
sites have been investigated as potential haz-
ardous waste sites.. They are catalogued in
the EPA's computerized database, CERCLIS
(for the Comprehensive Environmental Re-
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INTRODUCTION
sponse, Compensation, and Liability Informa-
tion System).
The damage to public health and thd environ-
ment that each site in CERCLIS might cause
is evaluated; many sites have been referred to
State and local,governments for cleanup. The
ERA lists the nation'sitnost serious hazardous
waste sites on the National Priorities List, or
NPL. (These Superfund sites are eligible for
federally-funded cleanup, but whenever pos-
sible the EPA makes polluters pay for the
contamination they helped create.) The NPL
now numbers 1,275 sites, with 50, to 100
added each year. By the end of the century,
the NPL may reach as many as 2,100 sites.
Superfund faces some of the most complex
pollution problems ever encountered by an
environmental program. Improperly stored or
disposed chemicals and the soil they contami-
nate are one concern. More difficult to correct
are the wetlands and bays, and the groundwa-
ter, lakes, and rivers often used for drinking
water that are contaminated by chemicals
spreading through the soil or mixing with
storm water runoff. Toxic vapors contaminate
the air at some sites, threatening the health of
people living and working near by.
Superfund aims to control immediate public
health and environmental threats by tackling
the worst problems at the worst sites first.
Wherever possible, Superfund officials use
innovative treatment techniques—many de-
veloped or refined by the EPA—to correct
hazardous materials problems once and for
all. Many of the treatment techniques they use
did not exist when the program was created.
The EPA Administrator had challenged Su-
perfund to complete construction necessary
for cleanup work at 130 NPL sites by the end
of the 1992 federal fiscal year. By September
30,1992, the end of fiscal year 1992, con-
struction had been completed at a total of 149
NPL sites. Superfund is well on its way of
meeting the Administrator's goal of complet-
ing construction at 200 NPL sites by the end
of fiscal year 1993, and 650 sites by the end
of fiscal year 2000.
Quick Cleanup at
Non-NPL Sites
Long-standing hazardous waste sites are not
Superfund's only concern. The EPA also re-
sponds to hazardous spills and other emergen-
cies, hauling away chemicals for proper treat-
ment or disposal. Superfund teams perform or
supervise responses at rail and motor vehicle
accidents, fires, and other emergencies in-
volving hazardous substances. They also
evacuate people living and working near by,
if necessary, and provide clean drinking water
to people whose own water is contaminated.
Removal crews also post warning signs and
take other precautions to keep people and ani-
mals away from hazardous substances.
Superfund employee prepares equipment for gro'undwaler
treatment.
VI
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INTRODUCTION
Quick Cleanups, or Removals, are not limited
to emergencies. When cleanup crews at con-
taminated sites find hazardous substances that
immediately threaten people or the environ-
ment, they act right away to reduce the threat
or to remove the chemicals outright. As the
EPA implements the Superfund Accelerated
Cleanup Model (SACM), more and more sites
will undergo quick cleanups, and many of
these will be cleaned up completely without
ever being included on the NPL. (See
"Streamlining Superfund: The Superfund Ac-
celerated Cleanup Model.")
Some of Superfund's most significant gains in
public health and environmental protection
have been won by the removal program. As of
March 31, 1992, the Emergency Response
Superfund employee removing drums from a Superfund site.
Program had logged more than 2,300 removal
completions since Superfund was established.
The Public's Role
Superfund is unique among federal programs
in its commitment to citizen participation. Al-
though the EPA is responsible for determin-
ing how dangerous a site is and how best to
clean it up, the Agency relies on citizen input
as it makes these decisions.
Community residents are often invaluable
sources of information about a hazardous
waste site, its current and previous owners,
and the activities that took place there. Such
information can be crucial to experts evaluat-
ing a site and its potential dangers.
Residents also comment on EPA cleanup
plans by stating their concerns and prefer-
ences at public meetings and other forums and
in formal, written comments to Agency pro-
posals. The EPA takes these comments and
concerns seriously, and has modified many
proposals in response to local concerns. For,
ultimately, it is the community and its citizens
that will live with the results of the EPA's de-
cisions and actions; it is only fair that citizens
participate in the process.
A Commitment to
Communication
The Superfund program is very serious about
public outreach and communication. Com-
munity relations coordinators are assigned to
each NPL site to help the public understand
the potential hazards present, as well as the
cleanup alternatives. Local information re-
positories, such as libraries or other public
buildings, have been established near each
NPL site to ensure that the public has an op-
portunity to review all relevant information
and the proposed cleanup plans.
The individual State volumes contain sum-
mary fact sheets on NPL sites in each State
and territory. Together, the fact'sheets-provide
a concise report on site conditions and the
progress made toward site cleanups as of
March 1992; The EPA revises these volumes
periodically to provide an up-to-date record of
program activities. A glossary of key terms
relating to hazardous waste management and
Superfund site cleanup is provided at the back
of this book.
VII
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INTRODUCTION
Superfund is, of course, a public program, and
as such it belongs to everyone of us. This vol-
ume, along with other State volumes, com-
prises the EPA's report on Superfund
progress to the program's owners for the year
1992.
VIM
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INTRODUCTION
STREAMLINING SUPERFUND: THE SUPERFUND
ACCELERATED CLEANUP MODEL
Historically, critics and supporters alike
have measured Superfund's progress
by the number of hazardous waste sites de-
leted from the NPL. Although easy enough to
tally, this approach is too narrow. It misses
the major gains Superfund makes by reducing
major risks at the nation's worst hazardous
sites long before all clean-up work is done
and the site deleted. It also ignores the Re-
moval Program's contributions to meeting
Superfund's twin mandates of maximizing
public health and environmental protection.
Renewing Superfund's commitment to rapid
protection from hazardous materials, the EPA
is streamlining the program. The Superfund
Accelerated Cleanup Model, or SACM, will
take Early Actions, such as removing hazard-
ous wastes or contaminated materials, while
experts study the site. SACM also will com-
bine similar site studies to reduce the time re-
quired to evaluate a site and its threats to
people and the environment. This way, imme-
diate public health and environmental threats
will be addressed while long-term cleanups
are being planned.
Emergencies such as train derailments and
motor vehicle accidents will continue to be
handled expeditiously. Teams of highly
trained technicians will swing into action
right away, coordinating the cleanup and re-
moval of hazardous substances to ensure pub-
lic safety as quickly as possible.
Breaking With Tradition
The traditional Superfund process begins with
a lengthy phase of study and site assessment,
but SACM will save time by combining sepa-
rate, yet similar, activities. Each EPA Region
will form a Decision Team of site managers,
risk assessors, community relations coordina-
tors, lawyers, and other experts to monitor the
studies and quickly determine whether a site
requires Early Action (taking less than five
years), Long-term Action, or both.
While the site studies continue, the Decision
Team will begin the short-term work required
to correct immediate public health or environ-
mental threats from the site. Besides remov-
ing hazardous materials, Early Actions in-
clude taking precautions to keep contaminants
from moving off the site and restricting access
to the site. Early Actions could eliminate most
human risk from these sites, and Superfund
will further focus its public participation and
public information activities on site assess-
ment and Early Action.
Long-Term Solutions
While Early Actions can correct many hazard-
ous waste problems—and provide the bulk of
public health and environmental protection—
some contamination will take longer to cor-
rect. Cleanups of mining sites, wetlands, estu-
aries, and projects involving incineration of
contaminants or restoration of groundwater
can take far longer than the three to five years
envisioned for Early Actions. Under SACM,
these sites will be handled much as they are
now.
Also under SACM, the EPA will continue its
pursuit of potentially responsible parties who
may have caused or contributed to site con-
tamination. Expedited enforcement and
procedures for negotiating potentially respon-
sible party settlements will secure their par-
ticipation. Superfund personnel will continue
to oversee clean-up work performed by poten-
tially responsible parties.
IX
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INTRODUCTION
HOW SUPERFUND WORKS
Each Superfund site presents a different
set of complex problems. The same haz-
ardous materials and chemicals often con-
taminate many sites, but the details of each
site are different. Almost always, soil is con-
taminated with one or more chemicals. Their
vapors may taint the air over and around the
site. Contaminants may travel through the soil
and reach underground aquifers which may be
used for drinking water, or they may spread
over the site to contaminate streams, ponds,
and wetlands. The contaminating chemicals
may interact with each other, presenting even
more complicated cleanup problems.
Superfund's cleanup process is arduous and
exacting. It requires the best efforts of hun-
dreds of experts in science and engineering,
public health, administration and manage-
ment, law, and many other fields.
The average NPL site takes from seven to ten
years to work its way through the system,
from discovery to the start of long-term
cleanup. Actual cleanup work can take years,
decades if contaminated groundwater must
be treated. Of course, imminent threats to
public health or the environment are cor-
rected right away.
The diagram to the right presents a simplified
view of the cleanup process. The major steps
in the Superfund process are:
• Site discovery and investigation to iden-
tify contaminants and determine whether
emergency action is required;
• Emergency site work such as removing
contaminants for proper treatment or dis-
posal, and securing the site to keep people
and animals away, if warranted by condi-
tions at the site;
• Site evaluation to determine how people
living and working nearby, and the envi-
ronment, may be exposed to site contami-
nants;
Detailed studies to determine whether con-
ditions are serious enough to add the site to
the National Priorities List of sites eligible
for federally funded cleanup under Super-
fund;
• Selection, design, and implementation of a
cleanup plan, after a thorough review of
the most effective cleanup options, given
site conditions, contaminants present, and
their potential threat to public health or the
environment.
• Follow-up to ensure that the cleanup work
done at the site continues to be effective
over the long term.
The Superfund Process
From the earliest stages, EPA investigators
work hard to identify those responsible for the
contamination. As their responsibility is es-
tablished, the EPA negotiates with these "re-
sponsible parties" to pay for cleaning up the
problem they helped create. This "enforce-
ment first" policy saves Superfund Trust Fund
monies for use in cleanups where the respon-
sible parties cannot be identified, or where
they are unable to fund cleanup work.
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THE VOLUME
How to Use the State Book
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 always is being
made at NPL sites, and the EPA periodically
will update the site fact sheets to reflect recent
actions and will publish updated State vol-
umes. The following two pages show a ge-
neric fact sheet and briefly describe the infor-
mation under each section.
How Can You Use
This State Book?
You can use this book to keep informed about
the sites that concern you, particularly ones
close to home. The EPA is committed 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 Super-
fund sites. Citizens are likely to be affected
not only by hazardous site conditions, but also
by the remedies that combat them. Site clean-
ups take many forms and can affect communi-
ties in different ways. Local traffic may be
rerouted, residents may be relocated, tempo-
rary 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.
XI
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THE VOLUME
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:
XX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX
:XXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX XXXXXXXX
xxxxxxxx5Bftw^jxxxx xxx xxxxxxxxxxxxx xx xxxxxx xxxx xxxxx xxxx x xxx xxxxxxxA
XXX XXx3ftB»^X.XXXX XXXXX XXXXXX XXXXXXXX XXXXXXXX XXXX XXXXXXXXXX XXXXX>i
XXXXXXXXXXXX XXXXXXXXX^fWJXX XXX XX XXXXXXXXX XXXXX XXXX XXXX XXXXX XXXXXXX XXXXXXXX
XXXXXXXXXXXX XX XXXXXXX XXX XXXXX xStet^JCXX XXXXXX XX XXXX XXX XXXXX XXX XXXXX XXX XXXXX
Site Responsibility:
Threats and Contaminants
NPL Listing History
Proposed: XX/XX/XX
Final: XX/XX/XX
XXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX
xxxxxxxx xxx xxxxxxxxxxxx xxxxx xxx xxxxxxxxxxxxx xx xxxxxx xxxx x:
XXX XXXXXXXXXX XXXXXXXX XXXXXXX XXX XXXXXX XXXXXX XXXXX XXXXXX XXXXX!
XXXXXXXX XXXX XXXXXXXXXX XXXXXXXX XXXXXXXXXXXX XXXXXXXXX XXXX X XXX XX XXXXXXXXX"
XXXX XXXX XXXXX XXXXXXX XXXXXXXX XXXXXXXX XXXXXXXXX XXXX XXXX XXXXX XXXX XXXXX:
Cleanup Approach
xxxxxx xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx xxxxxxxxxxxxx xxxxxx:
XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX XXXXXXXl
XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX X XXX XXXXXXXX
Response Action Status
XXXXXX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX XXXXXXX:
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 XXXXXX XXXXXXXX XXXXXXXX
:x 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 XXXXXXXX
Site Facts:
XXXXXX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX XX:
XXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX
. xxxxxxxxxxxx xxxxx xxx xxxxxxxxxxxxx xx xxxxxx xxxx xxxxx xxxx x xxx xxxxxxx:
^S()PCXXXX XXX XXXXXX
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
; xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx xxxxxxxxxxxxx xxxxxxx:
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.
XII
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THE VOLUME
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.
XIII
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THE VOLUME
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
Contaminated Groundwater resources
in the vicinity or underlying the site.
(Groundwater is often used as a drink-
ing 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 emis-
sions.)
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 Environ-
mentally Sensitive Areas in the vicinity
of the site. (Examples include wet-
lands and coastal areas or critical
habitats.)
Icons in the Response
Action Status Section
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 contamination
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 engineers
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.
XIV
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A SUMMARY OF THE STATE PROGRAM
xv
-------
Superfund
Activities in
Colorado
f Major Cil S3
• NPLSitea
The State of Colorado is located within
EPA Region 8, which includes six north central
States extending from the mid-western plains
to the Rocky Mountains. The State covers
104,091 square miles. According to the 1990
Census, Colorado experienced a 14 percent
increase in population between 1980 and 1990, and is ranked thirty-sixth in U.S. population with
approximately 3,294,000 residents.
The Colorado Hazardous Waste Clean Up Act, amended most recently in 1990, authorizes
funding, but provides no State enforcement authorities for site cleanup. Colorado instead participates
in site cleanup in accordance with the Federal Superfund program, when necessary entering into
cooperative agreements with the Federal government when a response action is relevant to the interest
of the State. In addition to the 10 percent contribution from the State required by the Federal
Superfund program, the State Hazardous Substances Response Fund is used to support administrative
functions, and to conduct removal and long-term clean up actions. The Colorado Comprehensive
Environmental Response, Compensation, and Liability Act Recovery Fund provides additional
funding for responses to natural resource damage. Currently, 16 sites in the State of Colorado have
been listed as final on the NPL. One new site was proposed for listing in 1992.
The Department of Health
implements the Superfund Program in the State of Colorado
Activities responsible for hazardous
waste contamination in the State of
Colorado include:
Other
Mining
Operations
Pesticide
Manufacturers,
Landfills/
Recycling
Operations
Chemical
and Metal
Production
Federal Facilities
Facts about the 17 NPL sites
in Colorado:
Immediate Actions (such as removing
hazardous substances or restricting
site access) were performed at 13
sites.
Two sites endanger sensitive environ-
ments.
Twelve sites are located near residen-
tial areas.
XVII
March 1992
-------
Most Sites Have Multiple Contaminants and
Contaminated Media:
Media Contaminated at Sites
Ground-
waiter
10 20 30 40 50 60 70 80 90 100
Contaminants Found at Sites
Percentage of Sites
Heavy Metals
VOCs
Radiation
Pesticides/Herbicides
Creosotes
71%
41%
35%
18%
12%
Percentage of Sites
In the State of Colorado, potentially responsible
parties are paying for or conducting cleanup
activities at 11 sites.
For Further Information on NPL Sites and Hazardous
Waste Programs in the State of Colorado Please Contact:
EPA Region 8 Public Affairs
Branch
National Response Center
The Department of Health: Office
of Environment, Hazardous
Materials and Waste Management
Division, Remedial Programs Section,
Superfund
EPA Region 8 Hazardous Waste
Management Division
EPA Superfund Hotline
For information concerning
community involvement
To report a hazardous
waste emergency
For information about the
State's responsibility in the
Superfund Program
For information about the
Regional Superfund Program
For information about the
Federal Superfund Program
(303)294-1120
(800) 424-8802
(303) 692-3398
(303) 294-7630
(800) 424-9068
March 1992
XVIII
-------
THE NPL REPORT
PROGRESS TO DATE
The following Progress Report lists all
sites currently on, or deleted from, the
NPL and briefly summarizes the status of ac-
tivities for each site at the time this report was
prepared. The steps in the Superfund cleanup
process are arrayed across the top of the chart,
and each site's progress through these steps is
represented by an arrow (O) indicating the
current stage of cleanup.
Large and complex sites often are organized
into several cleanup stages. For example,
separate cleanup efforts may be required to
address the source of the contamination,
hazardous substances in the groundwater, and
surface water pollution, or to clean up differ-
ent areas of a large site. In such cases, the.
chart portrays cleanup progress at the site's
most advanced stage, reflecting the status of
site activities rather than administrative ac-
complishments.
O An arrow in the "Initial Response" cate-
gory indicates that an emergency
cleanup, immediate action, or initial ac-
tion has been completed or currently is
underway. Emergency or initial actions
are taken as an interim measure to pro-
vide immediate relief from exposure to
hazardous site conditions or to stabilize
a site to prevent further contamination.
O A final arrow in the "Site Studies" cat-
egory indicates that an investigation to
determine the nature and extent of the
contamination at the site currently is on-
going or planned.
O A final arrow in the "Remedy Selection"
category means that the EPA has se-
lected the final cleanup strategy for the
site. At the few sites where the EPA has
determined that initial response actions
have eliminated site contamination, or
that any remaining contamination will
be naturally dispersed without further
cleanup activities, a "No Action" rem-
edy has been selected. In these cases,
the arrows are discontinued at the
"Remedy Selection" step and resume in
the "Construction Complete" category.
^> A final arrow at the "Remedial Design"
stage indicates that engineers currently
are designing the technical specifica-
tions for the selected cleanup remedies
and technologies.
OA final arrow in the "Cleanup Ongoing"
column means that final cleanup actions
have been started at the site and cur-
rently are underway.
O A final arrow in the "Construction Com-
plete" category is used only when all
phases of the site cleanup plan have
been performed, and the EPA has deter-
mined that no additional construction
actions are required at the site. Some
sites in this category currently may be
undergoing long-term operation and
maintenance or monitoring to ensure
that the cleanup actions continue to pro-
tect human health and the environment.
/ A check in the "Deleted" category indi-
cates that the site cleanup has met all
human health and environmental goals
and that the EPA has deleted the site
from the NPL.
Further information on the activities and
progress at each site is given in the site "Fact
Sheets" published in this volume.
XIX
-------
Progress Toward Cleanup at NPL Sites in the State of Colorado
Site Name
AIR FORCE PLANT PROJECTS
BRODERICK WOOD PRODUCTS
CALIFORNIA GULCH
CENTRAL CITY-CLEAR CREEK
CHEMICAL SALES COMPANY
DENVER RADIUM SITE
EAGLE MINE
LINCOLN PARK
LOWRY LANDFILL
MARSHALL LANDFILL
ROCKY FLATS PLANT (USDOE)
ROCKY MOUNTAIN ARSENAL
SAND CREEK INDUSTRIAL
SMELTERTOWN
SMUGGLER MOUNTAIN
URAVAN URANIUM PROJECT
(UNION CARBIDE CORP.)
WOODBURY CHEMICAL COMPANY
County
JEFFERSON
ADAMS
LEADVILLE
CLEAR CREEK/
GILPIN
DENVER
DENVER
EAGLE
FREMONT
ARAPAHOE
BOULDER
JEFFERSON
ADAMS
ADAMS
CHAFFEE
PITKIN
MONTROSE
NPL
Final
Final
Final
Final
Final
Final
Final
Final
Final
Final
Final
Final
Final
Proposed
Final
Final
Date
11/21/89
09/21/84
09/08/83
09/08/83
08/30/90
09/08/83
06/10/86
09/21/84
09/21/84
09/08/83
10/04/89
07/22/87
09/08/83
02/07/92
06/01/86
06/10/86
Initial Site Remedy Remedy Cleanup Construction
Response Studies Selected Design Ongoing Complete Deleted
ADAMS
Final 09/08/83
3
Sites
with
Studies
Underway
0
Sites
with
Remedy
Selected
2
Sites
with
Remedy
Design
11
Sites
with
Cleanup
Ongoing
1
Site
with
Construction
Complete
N
0
Deleted
Sites
y
Note: Cleanup status reflects actual site activities rather than administrative accomplishments.
-------
AIR FORCE RtA
PJKS
COLORADO
EPA ID# CO7570090038
EPA REGION 8
Jefferson County
Waterton
Site Description
The 464-acre Air Force Plant PJKS site is surrounded by about 4,700 acres of land owned by
Martin Marietta. Since 1957, wastes generated at the facility have consisted primarily of spent
solvents from equipment cleaning, contact and non-contact cooling water, and fuels
discharged as a result of engine and rocket testing. Contamination from trichloroethylene
(TCE), other hydrocarbons, rocket fuel components, and radiation was found in groundwater,
surface water, and soils. A total of 18 contamination plumes were found in two groundwater
zones. Some of these plumes are moving off Air Force property and onto the adjacent
Martin Marietta property. A total of 19 potential or known surface contamination sources
also were identified. The facility is located in a rural area with farming and ranching facilities.
Located nearby are major recreational areas used by local residents and visitors, including
Chatfield Reservoir, Roxbury State Park, Waterton Canyon.
Site Responsibility:
This site is being addressed through
Federal and State actions.
NPL LISTING HISTORY
Proposed Date: 07/14/89
Final Date: 11/21/89
Threats and Contaminants
7J3
Monitoring wells have detected TCE, trichloroethane, and freon contamination in
the groundwater. Discovery of thorium and gross alpha, beta, and gamma radiation
directed the Air Force to some low-level drummed wastes in a landfill. Brush
Creek, located on the site, also contains TCE. Direct contact with or accidental
ingestion of contaminated surface water, groundwater, or surface wastes may pose a
health threat to the nearby population.
March 1992
-------
Cleanup Approach
This site is being addressed in two stages: an immediate action and a single long-term
remedial phase focusing on cleanup of the entire site.
Response Action Status
Immediate Action: After the Air Force's monitoring revealed radiation
contamination, the source was traced to a small quantity of low-level radioactive
alloy that had been buried in drums in 1971. The Air Force located the
magnesium-thorium alloy and removed the drums safely off site in 1986 to a regulated
disposal facility. Uranium ore occurring naturally in the area may also contribute to the levels
of radioactivity found at this site.
Entire Site: The Air Force completed a draft report of an investigation at the
site that was reviewed by the EPA and the State. Further investigations have
been started to determine contamination in deeper groundwater zones. The Air
Force is preparing plans to conduct further investigations at certain contamination sources
and the deeper groundwater zones. Cleanup strategies for some surface sources and
groundwater contamination also are being developed.
Site Facts: The Air Force Plant PJKS site is participating in the Installation Restoration
Program (IRP), a specially funded program established by the Department of Defense
(DOD) in 1978 to identify, investigate, and control the migration of hazardous contaminants
at military and other DOD facilities.
Environmental Progress
The removal of contaminated drums has greatly reduced the potential for acute exposure to
hazardous materials at the Air Force Plant PJKS site while further investigations and cleanup
activities are taking place.
Site Repository
Denver Public Library, Central Library, 1357 Broadway, Denver, CO 80203
March 1992 2 AIR FORCE PLANT PJKS
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BRODERICK
PRODUCT
COLORADO
EPA ID#COD000110254
EPA REGION 8
Adams County
Denver
Site Description
The 64-acre Broderick Wood Products site is a former wood treatment plant with two main
activities that contributed to contamination: wood treatment operations between 1947 and
1981 and railroad shops on site before 1947. The wood preserving process used creosote and
pentachlorophenol (PCP) to treat power poles, fence posts, railroad ties, and other wood
products. Wastes were disposed of in various locations on the property, with the majority
piped to two unlined impoundments in the northwestern corner. These were called the "main"
and "secondary" impoundments, and were the primary sources of contamination on the site.
The main impoundment contained a surface layer of oil and grease, a water layer, and a
sludge layer. The secondary impoundment held mainly sludge. The combined contents totalled
about 2,200 cubic yards. No industrial activities currently take place on the site, but
contaminated buildings, equipment, and wastewater ponds still exist. None of the four former
ponds appears to have received plant wastewater, although a number of waste pits have been
discovered. The main access road to the site is barricaded, the treatment building is fenced,
the ponds have been excavated and sludges placed in a lined impoundment, and the site is
posted. A water supply well on the site was abandoned in the early 1970s, but several homes
to the north of the site continue to use well water. Fisher Ditch distributes water to irrigation
ditches that flow to Copeland Lake, used for power plant cooling. Approximately 79,000
people live within a 3-mile radius of the site; 2,900 people live within 1 mile. The nearest
home is 500 feet from the site. Clear Creek lies 1/2 mile to the north, as well as a sanitary
landfill and areas where sand and gravel mining have occurred.
Site Responsibility: This site is being addressed through
Federal and potentially responsible
parties' actions.
NPL USTING HISTORY
Proposed Date: 09/08/83
Final Date: 09/21/84
Threats and Contaminants
ZGJ
Groundwater, surface water, impoundment sludges, and soil are contaminated with
various polynuclear aromatic hydrocarbons (PAHs), PCP, and volatile organic
compounds (VOCs). In addition, some soil is contaminated with various heavy
metals. Direct contact with or accidental ingestion of contaminated groundwater or
soil may pose a health threat to the nearby population.
March 1992
-------
Cleanup Approach
The site is being addressed in two long term remedial phases focusing on cleanup of surface
impoundment sludges and soil and groundwater cleanup.
Response Action Status
Surface Impoundment Sludges: In 1989 potentially responsible parties
installed a security fence at the site. Under an Administrative Order issued in
1990, the potentially responsible parties excavated impoundment sludges and
stored them in lined impoundments. In a recent decision, the EPA modified the selected
remedy addressing these sludges. The sludges will be reclaimed. Actions for this phase of
the cleanup are expected to be completed in 1992.
Soils and Groundwater: In 1990, the potentially responsible parties began an
investigation, under EPA monitoring, that explored the nature and extent of
pollution at and around the property. The investigation, complete in 1991,
specifically targeted impoundment water, soils beneath impoundments, groundwater, surface
water, surface and subsurface soils, and structures located on the site. The remedy was
selected in early 1992. The remedies selected include: bioremediation of soils and sediment,
closure of the previously excavated impoundments, bioremediation of groundwater, and
reclamation of materials in tanks and containers. The design of the selected remedies is
scheduled to begin in mid-1992.
Site Facts: The EPA negotiated with Broderick Investment Company for studies to be
conducted at the site and signed a partial Consent Decree in 1986, requiring the company to
conduct a site investigation. An Administrative Order was signed in 1990 requiring the
potentially responsible parties to conduct cleanup of the surface impoundment sludges.
Environmental Progress
The installation of a security fence and the excavation and storage of the surface
impoundments sludges at the Broderick Wood Products site have reduced the potential for
exposure to hazardous materials and migration of hazardous substances while further cleanup
activities take place.
Site Repository
Adams Country Public Library, Commerce City Branch, 7185 Monaco Street,
Commerce City, CO 80022 ?-
March 1992 4 BRODERICK WOOD PRODUCTS
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CALIFORNIA
COLORADO
EPA ID#COD980717938
EPA REGION 8
Leadville County
100 miles west of Denver
Site Description
The 130 year old California Gulch site is a mining area covering 16 1/2 square miles of a
watershed area that drains along California Gulch to the Arkansas River. Starting in 1859,
the area was mined extensively for gold, lead, silver, copper, zinc, and manganese. California
Gulch contains numerous abandoned mines and wastes from mining, milling, and smelting.
Miners built the Yak Tunnel to drain water from the mine works and to make mineral
exploration and development easier. This tunnel drains hundreds of mines in its 4-mile
underground course and discharges a total of 210 tons of various heavy metals each year into
California Gulch. Although the tunnel mainly contaminates surface water, heavy metals also
have moved through surface water to pollute groundwater and sediments. California Gulch
also collects runoff from several other gulches that drain other mine tailings piles and pond
wastes. Some of this runoff flows through local town storm drains and city streets. The
Arkansas River, which receives water from the California Gulch, has been classified as a
recreational resource, and is used heavily for irrigation, livestock watering, public water
supplies, and fisheries. Approximately 6,000 people live in nearby Leadville and Lake County.
Site Responsibility:
This site is being addressed through
Federal and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date: 12/30/82
Final Date: 09/08/83
Threats and Contaminants
The primary contaminants of concern affecting surface water, sediments, and
groundwater are the heavy metals cadmium, copper, lead, arsenic, mercury, and
zinc. The water in several shallow groundwater wells in California Gulch and in
some private wells has been shown to exceed the EPA's drinking water standards
for cadmium and zinc. Arsenic, cadmium, and lead have been detected in waste
piles and soils. Adverse effects on the fish population have been observed in the
Arkansas River. Contaminants have degraded vegetation in pastures downstream,
and plant tissues in some cases contained levels of metals toxic to livestock and
wildlife. Water in the main stem of California Gulch is unsafe to drink. Other
potential threats to the health of the nearby population include direct contact with
contaminants in the soil.
March 1992
-------
Cleanup Approach
This site is being addressed in six stages: immediate actions and five long-term remedial
phases focusing on cleanup of the Yak Tunnel groundwater and surface water, mine waste
rock, smelter slag and additional areas.
Response Action Status
Immediate Actions: In 1986, EPA emergency workers extended public water
supply system lines to residences using private wells. In 1990, a potentially
responsible party improved the area storm water drainage system to prevent
surface water from coming into contact with mining wastes. This storm water drain system is
being upgraded to ensure that the system is effective in times when it is most needed.
Yak Tunnel: In 1988, the EPA selected a remedy to minimize the flow of acid
water from the Yak Tunnel and to prevent the uncontrolled release of tunnel
drainage to the environment. It features: (1) building a surge pond to capture
tunnel drainage and dissipate the effect of surges from the tunnel on the California Gulch
and the Arkansas River; (2) installing a permanent system to treat the tunnel water before
discharging it; (3) installing plugs at three places in the tunnel to stop the uncontrolled
discharge of mine drainage; (4) sealing shafts, drill holes, and fractured rock, and diverting
surface water to reduce the amount of water entering the tunnel; (5) establishing a surface
water and groundwater monitoring system; and (6) installing a pumping or drainage system to
control water levels. Under EPA monitoring, the parties potentially responsible for site
contamination are designing the remedies and conducting the cleanup. The parties finished
building the surge pond and filter unit in 1989 and currently are designing the permanent
treatment plant, which is scheduled for completion in mid-1992. All cleanup activities are
scheduled for completion by the end of 1993.
Groundwater and Surface Water: The EPA began an investigation in 1987 of
materials contributing to contamination of the site. Fullscale studies of surface
water and groundwater began in 1991 including surface water sampling, stream-
bed sampling, and toxicity testing of the California Gulch, adjacent drainages, and the
Arkansas River. Installation of 56 additional monitoring wells and piezometers is being done
as part of a larger groundwater study.
Mine Waste Rock: The potentially responsible parties began an investigation of
the mine waste rock area in 1991. The investigation is exploring the extent of lead
and zinc contamination contained in the mine waste rock. Runoff from this area
drains into surface water. The investigation is expected to be completed in 1993, at which
time alternatives for cleanup will be selected.
Smelter Slag: In 1991, the potentially responsible parties began an investigation
to determine the nature and extent of contamination of the smelter slag. The
investigation will explore the possibility of heavy metal releases from the slag.
Once the investigation is completed, expected in 1993, alternative cleanup options for final
remedy selection will be identified.
March 1992 6 CALIFORNIA GULCH
-------
Additional Ares: The EPA and the potentially responsible parties are beginning
studies of the residential soils, the smelter demolition debris/building materials,
the upland ecosystems, the alluvial channels, and the Arkansas River Valley in
1992. These studies will help define the nature and extent of contamination at these areas of
the site, as well as the best alternatives for cleanup.
Environmental Progress
Extending the public water supply has provided safe drinking water for affected area
residents. The surge pond and temporary filter unit treating surface waterflow in California
Gulch have been operational since 1989 and continue to provide environmental protection
while permanent treatments are sought for contaminated surface water and groundwater and
investigations at additional areas are underway.
Site Repository
Lake County Public Library, 1115 Harrison Avenue, Leadville, CO 80461
CALIFORNIA GULCH
March 1902
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CENTRAL CIT
CLEAR CREE
COLORADO
EPA ID#COD980717557
EPA REGION 8
lear Creek and Gilpin Counties
30 miles west of Denver
Other Names:
Argo Tunnel
Big Five Tunnel
Burlelgh Tunnel
Gregory Incline
National Tunnel
Quartz Hill Tunnel
Chase Gulch
Gregory Gulch
Golden Gilpin Mill
Boodle Mill
Clay County Tailings
North Clear Creek Tailings
Black Eagle Tailings
Little Bear Creek Tailings
McClelland Tailings
Site Description
The Central City-Clear Creek site is located approximately 30 miles west of Denver,
Colorado. The site boundary has not been narrowly defined because of the nature of the
contamination. Extensive activity at the site took place on a large number of small mining
claims. In general, this resulted in the disposal of mine waste rock and tailings piles over a
very large area. Additionally, numerous mine tunnels that were constructed for ore haulage
and mine water drainage have affected the area. These mine tunnels include: Argo Tunnel,
Big Five Tunnel, Burleigh Tunnel, McClelland Tunnel, and Rockford Tunnel (all on Clear
Creek); National Tunnel, Gregory Incline, and Quartz Hill Tunnel (all on North Clear
Creek). Consequently, the investigations at the site have involved identification and
prioritization of contamination within the approximately 400 square mile drainage basin for
Clear Creek. Clear Creek has three major tributaries as well as numerous smaller tributaries.
Recreational uses include fishing, kayaking, rafting, and tubing. Clear Creek and its
tributaries are used in whole or in part as a drinking water source by several municipalities
including Georgetown, Idaho Springs, Black Hawk, Golden, Westminster, Thornton, and
Arvada. Approximately 2,600 people live in Gilpin County; over 7,300 people reside in Clear
Creek County. Areas of both Counties were extensively mined in the past because of the
abundance of precious and base metals. Active mines are still present at some locations in
the Counties. In October 1991, limited stakes gaming was permitted in the towns of Black
Hawk and Central City. This will undoubtedly change the land use and population density in
these areas.
Site Responsibility: This site is being addressed through
Federal and State actions.
NPL USTING HISTORY
Proposed Date: 07/23/82
Final Date: 09/08/83
March 1992
-------
Threats and Contaminants
ZEJ
Soils, including tailings and waste rock, contain heavy metals such as arsenic,
cadmium, chromium, copper, and lead. Children may be at risk from playing on
these contaminated areas. Groundwater and surface waters also contain heavy
metals. Drinking contaminated groundwater from private wells in the shallow and
deep aquifers may pose a threat to the health of the nearby population. The
aquatic environment has been and continues to be severely affected by the elevated
levels of metals in Clear Creek and its tributaries.
Cleanup Approach
The site is being addressed in four stages: immediate actions and three long-term remedial
phases focusing on cleanup of mine surface water discharges, cleanup of tailings and waste
rock and control of discharges from Argo Tunnel and a Basin-wide study.
Response Action Status
Immediate Actions: In 1987, the EPA constructed a new retaining wall to
support the waste rock and tailings known as the Gregory Incline mine dump.
The EPA decreased the slope of the waste pile and replaced the retaining wall to
prevent it from collapsing into North Clear Creek. The EPA surveyed local households to
determine whether residents were using contaminated water from their private wells. Of the
wells tested, only one showed significant levels of contamination from cadmium. The EPA
provided the residents with bottled water as an interim measure until their home could be
connected to the Idaho Springs municipal water supply. Additionally, the EPA connected
four other nearby residences to the city water supply; these wells were at risk from future
contamination because they drew water from the same aquifer. The Colorado Department
of Health conducted a second survey in 1989, and two new problem wells were identified.
These will be addressed by future actions. In 1991, the EPA removed mercury contamination
from an abandoned trailer in Idaho Springs. The mercury was probably left over from a mine
assay laboratory operated inside the trailer.
CENTRAL CITY-CLEAR CREEK 9 March 1992
-------
Mine Surface Water Discharges: The EPA and the State plans to construct a
wetland passive treatment systems to treat the mine tunnel discharge from
Burleigh Tunnel before it reaches Clear Creek. The EPA already has constructed
a pilot-treatment system at Big Five Tunnel to determine the ability of passive treatment to
meet water quality standards. Results have been promising. An active treatment system
using chemical precipitation will be constructed to treat Argo Tunnel discharge. These
systems will be designed to reduce the mobility of dissolved and suspended metals in the mine
drainages, decrease the acidity of the mine drainages, and meet water quality standards.
Currently, the State and the EPA are carrying out the pilot program, and the State expects to
complete the design for addressing contamination of the site by 1993. In the future, the
State and the EPA will consider treating other mine tunnel discharges in the area.
Tailings/Waste Rock Remediation: Tailings and waste rock piles at the Argo
Tunnel, Gregory Incline, Big Five Tunnel, Quartz Hill Tunnel, and National
Tunnel will be graded to stable configuration and diversion ditches will be added to
the upslope side of the piles to provide drainage control. The tailings stabilization is
complete at Argo Tunnel and Gregory Incline. Tailings stabilization is being designed for Big
Five Tunnel, Quartz Hill Tunnel, and National Tunnel. Design of capping or erosion control
measures will soon begin for over two dozen other tailings and waste rock piles. The EPA,
the State, and local officials are evaluating institutional measures as a means to control
threats that future development on the tailings and waste rock piles could pose to the
population or the environment. The tailings stabilization of the entire site is expected to be
completed in 1993.
Argo Tunnel Discharge Control and Basin-Wide Study: In 1988, the EPA
conducted a study to evaluate ways to control further blow-outs from occurring at
Argo Tunnel and for reducing or stopping water from entering the tunnel. The
State's study, funded by the EPA through a Cooperative Agreement, was completed in the
spring of 1990. A decision was made on Argo Tunnel and the rest of the basin in late 1991,
after public review and comment. As a result of this study, the State identified three more
tunnels and 16 more tailings piles that will be addressed. The remedy chosen to cleanup the
three additional tunnels in Central City and Hawk Counties include collecting the
contaminated water and disposing of it outside the town area. The EPA will explore if
further treatment is necessary. Construction of capping or retaining walls and erosion control
measures is the remedy selected to address treatment of the 16 tailing piles. Within the
vicinity of Argo Tunnel, an extraction and treatment by chemical precipitation system will be
designed to capture contaminated groundwater before it reaches Clear Creek. The Colorado
Department of Health also will seek volunteers for private groundwater well testing. This will
be the third such solicitation. Owners of wells contaminated with metals resulting from
mining activities will be eligible to receive bottled water or will be connected to a public water
supply. The design of the remedy began in late 1991.
Site Facts: In 1989, the EPA entered into an Interagency Agreement with the U.S. Bureau
of Reclamation to proceed with the cleanup action for the tailings and waste rock area. The
Colorado Department of Health is leading all other cleanup activities. The EPA funded a
study conducted by the State on discharges from Argo Tunnel through a Cooperative
Agreement; the study was completed in 1990.
March 1992 10 CENTRAL CITY-CLEAR CREEK
-------
Environmental Progress
The construction of a new retaining wall to support the waste rock and tailings has prevented
the further spread of contamination from the Gregory Incline mine dump into North Clear
Creek. The EPA provided affected residences with bottled water prior connecting them to
the municipal water supply and later connected four other residences to the city water supply.
The stabilization of tailings and waste rock piles is underway, and remedies have been chosen
for the treatment of the acidic water and the design of those systems is underway. These
cleanup activities have reduced threats to the nearby population and environment while
further actions are being planned and taking place.
Site Repository
Idaho Springs Public Library, 219 14th Avenue, Idaho Springs, CO 80452
CENTRAL CITY-CLEAR CREEK
11
March 1992
-------
CHEMICAL SAL
COMPANY
COLORADO
EPAID#COD007431620
EPA REGION 8
Denver County
2 miles northwest of Stapleton
International Airport
Other Names:
Dahlia NPL Staging Area
Site Description
The Chemical Sales Company site is located in a predominantly light industrial area in
northeastern Denver and covers approximately 5 square miles. The company is a wholesale
distributor of commercial/industrial chemicals, detergents, and water leisure products.
Operations include the storage and repackaging of bulk chemicals from rail cars and drums.
A warehouse located on site has been owned and operated by the company since 1976.
Surface and underground storage tanks, ranging in size from 5,000- to 15,000-gallons, were
installed between 1976 and 1977. In 1981, as a result of EPA-sponsored national random
sampling of drinking water, the groundwater in the South Adams County Water and
Sanitation District (SACWSD) as found to be contaminated with organic chemicals. This lead
to the discovery of Chemical Sales Company as the main source of the organic chemical
contamination. There have been two known spills at the site, one of which occurred in 1985
when approximately 200 gallons of methylene chloride were spilled as a result of a spigot
breaking off a tank. In 1986, the discharge of contaminated water from the company property
was discovered by the Denver Fire Department. The transfer pipe gallery between the
storage tanks and the loading dock had filled with runoff water. The pipe gallery was pumped
into a nearby drainage ditch along the railroad tracks.
Site Responsibility: This site is being addressed through
Federal and potentially responsible
parties' actions.
Threats and Contaminants
NPL LISTING HISTORY
Proposed Date: 06/24/88
Final Date: 08/30/90
High concentrations of volatile organic compounds (VOCs), such as
tetrachloroethylene (PCE), trichloroethylene (TCE), methylene chloride, and
chloroform, were detected in groundwater samples. The EPA detected VOCs in the
soil in and around the Chemical Sales Company property. Ingestion of
contaminated groundwater or inhalation of vapors while using groundwater pose
the greatest potential risks. Potential health risks may exist for individuals who
come in direct contact with the contaminated soil or groundwater. The site has
been identified as a potential source of contamination of the South Adams County
alluvial aquifer.
12
March 1992
-------
Cleanup Approach
The site is being addressed in five stages: immediate actions and four long-term remedial
phases focusing on controlling the source of contamination and cleanup of the groundwater,
residential wells, and well 18.
Response Action Status
Immediate Actions: In the summer of 1986, SACWSD connected its water
system to a temporary treatment system to provide safe drinking water to its
customers. At the same time, the EPA began hookup of about 400 residences, all
of whom who were using private alluvial wells for indoor purposes, to the SACWSD system.
In 1987, construction was begun on a permanent treatment plan for SACWSD (Klein Water
Treatment Plant). This project was completed and put on line in 1989. In 1989, the EPA
removed leaking and corroded drums containing contaminated soils, solvents, and liquids
discovered during the EPA's investigation. Drums were removed to a federally approved
disposal facility.
Source Control: Under EPA oversight, Chemical Sales Company initiated an
investigation in 1989 to determine the source of contamination at the site and to
identify alternative technologies to control these sources. The study, completed in
February 1991, recommends the following remedy: treating contaminated soils through the
use of soil vapor extraction. This selected remedy was signed by the EPA in mid-1991; the
design of the cleanup strategy is expected to begin in 1992.
Groundwater: The EPA initiated an investigation in 1989 to determine the
extent of groundwater contamination at the site. The EPA collected groundwater
samples from 80 wells in the site area. Based on the site investigation results, the
EPA proposed the following remedy in 1991: using groundwater extraction wells to prevent
further migration of groundwater contamination and treating contaminated groundwater
through the use of air stripping to meet federal and State drinking water standards. The
treated water will be reinjected into the aquifer. The design of the cleanup strategies is
expected to begin in 1992.
Residential Wells: In 1990, the EPA began an investigation to determine how
many private alluvial wells were not hooked up to the SACWSD system in the
aquifer. In August 1990, a Colorado Department of Health and Tri-County
Health survey identified 12 residences that were using shallow wells located within
contaminated portions of the alluvial aquifer. Based on the site investigations, the EPA
decided in 1991 to connect the affected residences to the SACWSD water supply system. The
EPA has completed designing the remedy and anticipates connecting those residence to the
municipal water system by the end of 1992.
Well 18: In 1991, the EPA began an investigation to determine the nature and
extent of contamination at this well. The study is expected to be completed in
1993 and lead to the selection of a final cleanup remedy.
CHEMICAL SALES COMPANY 13 March 1992
-------
Site Facts: The EPA entered into an Administrative Order in consent with Chemical Sales
Company, requiring them to conduct an investigation of site contamination and to identify
alternative cleanup technologies.
Environmental Progress
By constructing a water treatment facility and connecting residences to the municipal water
system, the EPA provided residences with safe drinking water. Removing and disposing of
drums containing hazardous materials and securing the area have reduced the threat of
exposure to contaminants at the Chemical Sales Company site. Investigations leading to the
selection of remedies for the contaminated groundwater and control of the sources of
contamination have been completed and designs of the strategies are underway.
Site Repository
Not established.
March 1992
14
CHEMICAL SALES COMPANY
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DENVER RA
SITE
COLORADO
EPA ID#COD980716955
Site Description
EPA REGION 8
Denver County
Denver
Forty-nine properties in Denver are contaminated with radioactive soils and debris abandoned
after the collapse of the city's World War I-era radium industry. Following the demise of the
industry in the late 1920s, people soon forgot about the origin, location, and nature of the
refining wastes. An EPA investigator discovered the situation in 1979 while reviewing some
old documents. The State, with help from several agencies, undertook an extensive study and
found 35 sites where radium had been processed, refined, or fabricated into various devices
or products. The number of properties affected has since expanded to 49, with 48 in the
metropolitan Denver area. These 48 properties were combined into 9 groups for cleanup
activities. These group are: (1) 12th and Quivas Properties; (2) llth and Umatilla
Properties;(3) 1000 W. Louisiana Properties; (4) Robinson Brick Company (ROBCO) and
Denver and Rio Grande Western (D&RGW) Properties; (5) Card Property; (6) Open Lands;
(7) Denver Street; (8) Shattuck Chemical Property; and (9) ROBCO - Non-Radioactive
Contamination.
Site Responsibility: This site is being addressed through
Federal and State actions.
Threats and Contaminants
NPL USTING HISTORY
Proposed Date: 10/23/81
Final Date: 09/08/83
The soil is contaminated with radium, thorium, uranium, arsenic, and lead.
Although the immediate threat to public health and the environment is limited,
redevelopment of contaminated properties or further dispersal of the wastes could
increase the exposure risk if the contaminated material is not removed and disposed
of safely. The principal threat arises from the buildup of radon gas in structures
built over the contaminated soil. In addition, direct contact with the wastes may
pose a health risk.
Cleanup Approach
This site is being addressed in ten stages: emergency actions and nine long-term remedial
phases focusing on cleanup of the identified contamination areas and properties. Some of
these separate units contain multiple long-term remedial phases.
15
March 1992
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Response Action Status
Emergency Actions: In 1985, EPA emergency workers arrived at an appliance
refurbishing facility to remove radon gas from between the walls. They installed a
wall with ventilation systems along two sides of the operation's basement. This
action resulted in a decrease of the radon concentrations to levels well below EPA standards.
12th and Quivas Properties: In 1987, the EPA selected a remedy for this
portion of the site including: (1) excavating the contaminated soil lying in open
areas and under several structures on the properties; and (2) transporting the soil
to a permanent disposal site. Cleanup activities began in 1989 and were completed in 1991.
Workers removed 33,000 tons of contaminated soil and backfilled with clean soil, regrading to
the original contours. Where buildings were constructed over contaminated soil, cleanup
workers removed the floors to excavate underlying wastes, and then replaced the floors.
11th and Umatilla Properties: The EPA selected a remedy for the area in
1987. Features of the remedy are: (1) excavating contaminated soil from open
areas and from under buildings; and (2) disposing of the contaminated material at
a permanent disposal facility. The EPA anticipates leaving waste beneath certain on-site
structures and estimates that 85,000 tons of contaminated material will be removed from the
property and replaced with clean fill. This project is scheduled for completion in 1992. The
U.S. Bureau of Reclamation is managing the transport and disposal of all wastes from the
Denver Radium site.
1000 W. Louisiana Properties: The EPA selected a remedy for this portion of
the site in 1987. The remedy includes: (1) cleaning up the Creative Illumination
property; (2) excavating the contaminated soil remaining on the 1000 W. Louisiana
properties; and (3) removing the contaminated material from the properties to the permanent
disposal facility. Cleanup activities began in 1989, with the demolition of the contaminated
brick building at 1298 S. Kalamath Street. Workers have excavated 64,000 tons of
contaminated soil, and demolished one contaminated building. The EPA is considering leaving
waste that extends under the streets in place.
ROBCO and D&RGW Railroad Properties: The EPA selected a remedy for
the ROBCO property and the adjacent D&RGW Railroad property in 1986. The
remedy featured: (1) removing contaminated soil from the ROBCO property and
the D&RGW Railroad property; (2) demolishing the contaminated laboratory and office
buildings on the ROBCO property and removing 200 cubic yards of debris; (3) disposing of
the contaminated soil and debris at a permanent disposal facility; and (4) continuing periodic
groundwater monitoring. Over 96,000 tons of contaminated waste were excavated and safely
disposed of. The decontamination work was completed in 1991.
March 1992 16 DENVER RADIUM SITE
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Card Property: The EPA selected a remedy for this subsite in 1987 which
includes: (1) excavating 4,000 cubic yards of contaminated soil and sediments from
the Card property; (2) temporarily storing this waste in reinforced synthetic bags
placed inside a building at the site; (3) possibly staging or storing wastes from other subsites
on the Card property, but not more than 13,000 cubic yards total; (4) removing all
contaminated material to a permanent disposal facility; and (5) decontaminating and
dismantling the True Truss building and disposing of the material in a sanitary landfill. All
plans for temporary storage of waste on the site were abandoned when a permanent disposal
facility became available. The EPA began excavation and disposal of contamination wastes in
1988 and completed these cleanup activities in 1989.
Open Lands: The EPA selected a remedy for the open lands in 1987 before the
permanent disposal site had been found. It featured: (1) capping 290 cubic yards of
contaminated material; and (2) removing 1,020 cubic yards of wastes and
temporarily storing them. The EPA began excavation and disposal of contaminated wastes in
1990 and is scheduled to complete these activities in 1992; to date, workers have excavated
5,600 tons of contaminated soil from ten properties. The EPA estimates that an additional
2,000 tons will be excavated from the last remaining property in 1992.
Denver Streets: In 1986, the EPA chose a "no action" remedy for several
Denver street segments where the subsurface contains contaminated paving
materials. The remedy is to leave the contaminated material in place; however,
institutional controls governing routine maintenance, repair, and construction
activities on the affected streets will be set up to ensure that the area is not disturbed or
developed and to remove and properly dispose of any contaminated material excavated. The
State has taken the lead in developing institutional controls that will protect human health
and the environment.
Shattuck Chemical Property: The Colorado Department of Health, assisting
the EPA in the cleanup action, has completed a study of the nature and extent of
contamination as well as various cleanup alternatives. A proposed plan discussing
the remedy preferred by the EPA and the State was released for public comment in 1991.
The preferred alternative was identified as excavation of the contaminated soils and off-site
disposal. The proposed plan also considered the feasibility of solidifying the soils by mixing
them with cement or a similar material. The resulting solidified mass could then be safely left
in place beneath a cap. The final remedy was selected and published in 1992. On-site
treatment to solidify the soils was the selected remedy.
ROBCO - Non-Radioactive Contamination: During the cleanup of
radioactive contamination at the ROBCO site, non-radioactive soil contamination
was discovered. The EPA conducted additional investigations to identify the area,
extent, and concentration of contaminants of these materials and to evaluate the best
remedies for addressing the metals contamination. A final remedy was selected in 1992 and
consists of capping the contaminated soils with cleanfill material, which will serve as a barrier
to prevent direct exposure to the metals contamination. Design of the remedy is underway.
Actual cleanup activities are scheduled to be completed in late 1992.
DENVER RADIUM SITE 17 March 1992
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Environmental Progress
Extensive cleanup work has been completed at the Denver Radium site, including the
removal and safe disposal of over 225,000 tons of contaminated materials. Additionally,
cleanup actions have addressed immediate sources of radon and have protected workers from
short-term exposure. Many additional actions are currently underway at the Denver Radium
site which will continue to reduce sources and levels of contamination.
Site Repository
Denver Public Library, Central Library, 1357 Broadway, Denver, CO 80203
March 1992
18
DENVER RADIUM SITE
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EAGLE MINE
COLORADO
EPAID#COD081961518
Site Description
EPA REGION 8
Eagle County
8 miles west of Vail
Other Names:
New Jersey Zinc, Inc.
Oilman
The Eagle Mine site includes the Eagle Mine workings, the town of Oilman, the mine tailings
pond areas, Rex Rats, Rock Creek Canyon, and waste rock and roaster piles. This site
encompasses an area of approximately 5 to 7 miles along the Eagle River. Over the last 100
years, zinc miners deposited about 7 million tons of mine wastes and mill tailings along the
Eagle River. The mining conditions and wastes formed acid, which leached toxic metals into
surrounding surface water and groundwater. Five major sources of contamination have been
identified at the site: (1) ponds containing tailings over a total of 107 acres; (2) roaster piles,
five of which are found at this site; (3) a 25-acre pipeline corridor that extends from Rex
Flats to the new tailings pond; (4) twelve major waste rock piles that cover about 93 acres;
and (5) groundwater that has flooded the mine. Access to one of the local wilderness areas
runs through the site and next to the old tailings pond. The closest residence to the Eagle
Mine site is approximately 1,000 feet to the northwest. Minturn, the closest population
center, has 1,500 people, and its filter ponds and municipal wells lie 2,000 feet to the
northwest of the mine tailings and across Cross Creek. Minturn draws its public water supply
both from area wells and from Cross Creek. A middle school is located only 400 yards from
the largest tailings pile.
Site Responsibility:
This site is being addressed through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 10/15/84
Final Date: 06/10/86
Threats and Contaminants
EE3
Soil, surface water, and groundwater below the tailings piles and the now-flooded
mine contain various heavy metals including arsenic, cadmium, chromium, copper,
lead, and zinc. Fish populations have declined in the reaches of the river next to
mine waste areas. Water from three private wells located downgradient from the
Eagle Mine site could pose a health risk if used as drinking water. Wind-blown
particulates from the tailings pile are of concern because of the proximity of a
middle school. One wetland area, Maloit Park, located adjacent to the new mine
tailings pile, may be affected by surface water and groundwater flowing from the
pile and from mass wastage off an adjacent tailings pile.
19
March 1992
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Cleanup Approach
This site is being addressed in three stages: initial and emergency actions and two long-term
remedial phases focusing on cleanup of the entire site and the soils.
Response Action Status
Initial and Emergency Actions: Between 1976 and 1979, the mine owners
undertook early cleanup activities such as treating mine water, revegetating small
test plots located in the Rex Rats and old tailings pond areas, and building
surface water diversion ditches along the old and new tailings ponds. Workers removed
about half the tailings deposited on Rex Flats and built a surface runoff ditch. They also
built a seepage collection pond and a sump and liming facility between the old tailings pond
and the Eagle River. When the mine was abandoned in approximately 1983 and the pumps
were turned off, the mine began to flood. Transformers containing polychlorinated biphenyls
(PCBs), located in the mine shaft, threatened to erode and spread contaminants throughout
the lower mine levels and to the Eagle River. EPA emergency workers removed the
transformers from the shaft, secured and stored them on site as usable products, and supplied
the electricity needed to run the pump and water treatment systems while the salvage
operations were underway. They also constructed dikes in the mine to divert water from the
upper mine areas and to prevent its release.
Entire Site: In 1988, the State selected a remedy for cleaning up the sources of
pollution at the site featuring: plugging the mine portals; removing the roaster
piles, Rex Flats tailings, and tailings pile and consolidating them in the "new"
tailings pile; capping the new pile and pumping groundwater; and monitoring the Eagle River.
The State and a potentially responsible party reached an agreement on performance of a
long-term cleanup action. To prevent discharge of contaminated water to the river from the
mine, the former owners constructed five concrete bulkheads in mine openings. A temporary
lime treatment system was constructed at the old pond to neutralize runoff prior to discharge
to the river. Under State monitoring, the former mine owners plugged the mine and
reworked many millions of cubic yards of mine tailings. They have consolidated
approximately 95 percent of the wastes from the roaster piles, Rex Flats, and the old tailings
pile into the new tailings pile. In early 1990, however, it became apparent that problems had
developed with the ongoing cleanup. Mine seepage, a failed groundwater pump-back system,
and run-off from various tailings areas were putting a large quantity of metals into the Eagle
River. In 1990, the State and the potentially responsible party agreed to place a water
treatment plant on site and to collect and treat visible mine seepage and consolidated pile
groundwater. A second selection of remedies outlining necessary cleanup measures is
expected to be determined in late 1992.
March 1992 20 EAGLE MINE
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Soils: In late 1992, an investigation is scheduled to begin to explore the nature
and extent of contaminated soils at the Eagle Mine site. The study is expected to
be completed in late 1993, and lead to the selection of a final cleanup remedy.
Environmental Progress
The EPA has taken emergency actions at the Eagle Mine site to remove the PCB-laden
transformers and to construct dikes to prevent the further spread of contamination. To date,
most of the tailings and roaster pile material has been consolidated at the new tailings pile,
which is 40 percent capped. A groundwater extraction system is operational, and the mine is
plugged and nearly completely flooded. However, water drainage treatment and monitoring
river impacts will continue while long-term cleanup actions and additional site investigations
are underway in order to protect the Eagle River from contaminated runoff from the site.
Site Repository
Town Clerk's Office, Minturn Town Hall, 302 Pine Street, Minturn, CO 81645
EAGLE MINE
21
March 1992
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LINCOLN PA
COLORADO
EPA ID#COD042167858
EPA REGION 8
Fremont County
Canon City
Other Names:
Uranium Mill
Cotter Corporation
Site Description
Beginning in 1958, the Cotter Corporation operated a uranium mill approximately 1 1/2 miles
from the community of Lincoln Park. Mill operations caused the release of radionuclides and
heavy metals into the environment. Contaminants migrated through the groundwater to
Lincoln Park prior to the construction of a dam on Sand Creek. Drinking water wells in the
impacted area have been abandoned and residents have stopped using groundwater for
domestic purposes. These homes have been connected to the Canon City water supply;
however, some individuals in Lincoln Park are still using groundwater for irrigation purposes.
The Lincoln Park area has approximately 3,500 residents.
Site Responsibility:
This site is being addressed through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 09/08/83
Final Date: 09/21/84
Threats and Contaminants
ZGJ
Groundwater underlying the mill area and the community of Lincoln Park has been
shown to be contaminated with uranium and other radionuclides. Soils in the mill
area also are contaminated with similar uranium products. Drinking or otherwise
coming into contact with contaminated well water may cause adverse health effects.
Wind-blown contaminants and migration of contaminants through surface streams
also pose potential threats.
Cleanup Approach
This site is being addressed in a single long-term remedial phase focusing on cleanup of the
entire site.
22
March 1992
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Response Action Status
Entire Site: In 1988, the State, with the EPA's approval, selected a remedy to
clean up the site by: connecting area residences to an alternate water supply;
pumping and treating the groundwater above the dam on Sand Creek to remove
the contaminants; flushing the contaminants out of the water below the dam; revegetating
the site; implementing air quality controls; and stopping off-site groundwater migration. Area
residences have been furnished with safe drinking water. A pilot groundwater treatment
system has been installed. Soil, vegetation, and sediment sampling is continuing. To date,
the Cotter Corporation has contained the contaminants from the uranium mill using a
groundwater cut-off barrier and by pumping the water back into holding ponds. The
company is designing the technical specifications for the remedy. Most of the design phase is
scheduled to be completed in 1992. A risk study of the site, to be completed in early 1992,
will help the EPA determine the effectiveness of selected cleanup remedies.
Site Facts: In 1988, the State and the Cotter Corporation signed a Consent Decree, under
which the Cotter Corporation agreed to clean up the contamination at the site.
Environmental Progress
Residences near the Lincoln Park site have been furnished with safe drinking water. A pilot
groundwater treatment system has been installed and containment measures have been taken
at the site to prevent uranium-contaminated groundwater from migrating off the mill site.
Currently, the design for the cleanup remedies that will restore the site to environmentally
safe levels is underway.
Site Repository
Canon City Library, 516 Macon Avenue, Canon City, CO 81212
LINCOLN PARK 23 March 1992
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LOWRY LAN
COLORADO
EPA ID# COD98049924
EPA REGION 8
Arapahoe County
2 miles east of Aurora
Other Names:
Lowry Disposal Area
djtyind County of Denver Landfill
jConoBO City and County of Denver
Landfarm
Denver Arapahoe Disposal
Site Description
The Lowry Landfill covers approximately 400 acres near Aurora, a suburb of Denver. It is
estimated that approximately 145 million gallons of liquid industrial wastes were dumped into
65 unlined trenches or pits in the landfill from 1966 until 1980. These wastes included
sewage sludges, metal plating wastes, petroleum-derived products, pesticides, and industrial
solvents. Municipal refuse was added to the pits to soak up the liquids. This industrial waste
disposal method, known as co-disposal, was discontinued in 1980. Beginning at that time, the
landfill accepted only solid waste for disposal. In addition to the industrial wastes at the site,
approximately 8 million tires were stockpiled in the 1970s in the hope that they might be
recycled as a source of fuel or other raw material. Chemical Waste Management, Inc. took
over the operation of the landfill in 1980. The wastes have migrated into the groundwater
and surface water. Liquid wastes that reached the land surface have formed a contaminated
stream within the site. Surface water runoff and liquid wastes from the site drain into an
unnamed creek that flows into a holding pond. The unnamed creek is intermittent and flows
to the north into Murphy Creek, which crosses farmland and various subdivisions before
flowing into Toll Creek, and from there into a tributary of the South Platte River. The area
around the site is zoned for future industrial, commercial, and residential development. The
population within 1 mile is less than 500 people. Approximately 5,000 people live within 3
miles of the site.
Site Responsibility: This site is being addressed through
Federal, local, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 09/08/83
Final Date: 09/21/84
24
March 1992
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Threats and Contaminants
The air, shallow groundwater, sediments, soils, and surface water contain one or
more of the following: organic chemicals, radionuclides/ionizing radiation, and
inorganic chemicals. Although the shallow ground water is contaminated, it is not
used for drinking water sources. The potential exists, however, for the
contaminants to migrate into the deep groundwater, the source of drinking water in
the area. The EPA has determined that the site does not pose any immediate risks
to public health.
Cleanup Approach
The site is being addressed in seven stages: initial actions and six long-term remedial phases
focusing on cleanup of the shallow groundwater and other subsurface liquids, landfill gas,
landfill solids, soils, surface water and sediment, and deep groundwater.
Response Action Status
Initial Actions: In an initial action in 1984, the City and County of Denver
constructed an underground barrier wall and treatment system. The wall
functions as a dam to contain and collect shallow groundwater, which is pumped
into storage tanks and piped to an on-site plant for treatment. The treated water is
discharged into an underground gravel drain off site, where it slowly seeps into the ground.
In 1989, the City and County of Denver began to shred the discarded tires that are stockpiled
at the site. The shredding is expected to be completed in 1992. In 1990, the EPA bulked
and removed drums containing wastes and treated the liquids in an on-site wastewater plant.
Shallow Groundwater and Subsurface Liquids: In 1988, the Lowry Coalition,
a group of 14 potentially responsible parties, under EPA guidance, began studying
the shallow groundwater and subsurface liquids beneath the site to determine the
extent of the contamination. This study is being performed in conjunction with the deep
groundwater study. Completion is expected in 1993.
Landfill Gas: In 1990, the City and County of Denver, Waste Management of
Colorado Inc., and Chemical Waste Management, Inc. began a study of the gas
accumulating in the landfill. This study will investigate methane and other gases
generated at the site and will determine the extent to which contaminant vapors may have
migrated from the landfill. This study is scheduled to be completed in 1993.
LOWRY LANDFILL 25 March 1992
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Landfill Solids: In 1990, the City and County of Denver, Waste Management of
Colorado, Inc., and Chemical Waste Management, Inc. began a study, under EPA
monitoring, of the solid refuse disposed of at the site. This includes the buried
drums, tires, and other debris in the unsaturated waste pit area. Once this study is completed
in 1993, effective environmental measures will be recommended.
Soils: In 1991, the City and County of Denver and Metro Wastewater
Reclamation District began a study, under EPA monitoring, of soil contamination.
This investigation is expected to be completed in 1993.
Surface Water and Sediment: In 1991, the City and County of Denver and
Metro Wastewater Reclamation District began a study of the surface water and
sediment contamination both on and off the site. The study is scheduled to be
completed in 1993. In 1991, a Consent Decree was signed by the City and County of Denver
and Waste Management of Colorado, Inc. to modify the surface water treatment system to
treat a wider range of contaminants and prevent the off-site overflow of an unnamed creek
during high precipitation events.
Deep Groundwater: In 1989, the Lowry Coalition, under EPA guidance, began
studying the deep groundwater. This study is being performed in conjunction with
the shallow groundwater and subsurface liquids investigation. It is scheduled for
completion in 1993.
Site Facts: In 1988, the EPA and the Lowry Coalition reached an agreement to investigate
shallow groundwater contamination at the site. In 1989, the coalition agreed to broaden the
investigation to include deep groundwater. In 1990, an Administrative Order on Consent was
signed by the City and County of Denver, Waste Management of Colorado, Inc., and
Chemical Waste Management, Inc. for performance of investigations of the landfill solids and
gas contamination. In 1991, an Administrative Order on Consent was signed by the City and
County of Denver and the Metro Wastewater Reclamation District for performance of
investigations into soil, surface water, and sediment contamination. In 1991, an
Administrative Order on Consent was signed by the City and County of Denver, Waste
Management of Colorado, Inc., and Chemical Waste Management, Inc. to modify the surface
water treatment system.
Environmental Progress
By constructing an underground barrier wall and treatment system, the City and County of
Denver have contained the contaminated shallow groundwater and have prevented it from
migrating off the site to cause further pollution. Additionally, removal of deteriorating drums
was conducted to protect the environment while site investigations are continuing. Various
investigations currently are underway to evaluate the extent of the contamination at the site.
These studies will result in the selection of final remedies for all the affected areas of the
Lowry Landfill site.
March 1992 26 LOWRY LANDFILL
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Site Repository
Aurora Public Library, Central Library, 14949 East Alameda Drive, Aurora, CO 80012
LOWRY LANDFILL 27 March 1992
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MARSHALL
COLORADO
EPA ID# COD98049925
PA REGION 8
Boulder County
Town of Marshall
Site Description
The Marshall Landfill, covering 160 acres, is immediately south of Colorado Highway 170 and
is bounded on the east by South 66th Street. Marshall Reservoir is upstream of the site,
about 2,000 feet to the west. The site is divided into two adjacent sections: an inactive
80-acre section that served as a landfill and an 80-acre section actively serving as a privately
owned and operated landfill. Between 1965 and 1974, the inactive landfill accepted
unstabilized sewage sludge and many unidentified and potentially hazardous wastes. Septic
wastes, and possibly liquid industrial wastes, also were disposed of off site in two septic ponds.
The ponds are now closed. The active landfill currently accepts only municipal wastes. In
1981, landfill leachate was observed seeping into the community ditch that carries drinking
water from nearby Marshall Lake to the City of Louisville and serves as irrigation water for a
reservoir and irrigation company.
Site Responsibility:
This site is being addressed through
Federal and potentially responsible
parties' actions.
NPL USTING HISTORY
Proposed Date: 07/23/82
Final Date: 09/08/83
Threats and Contaminants
Volatile organic compounds (VOCs) and inorganic chemicals have been detected in
the groundwater both on and off site and in surface waters on the site. Drinking
contaminated groundwater could present a health threat to individuals.
Cleanup Approach
The site is being addressed in two stages: immediate actions and a long-term remedial phase
focusing on cleanup of the groundwater and surface water both on and off site.
28
March 1992
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Response Action Status
Immediate Actions: In 1984, Landfill, Inc. installed a 60-inch pressurized
pipeline to protect local drinking water supplies by transporting the water across
the landfill.
Groundwater and Surface Water: The selected groundwater and surface water
cleanup technologies to address VOC and inorganic chemical contamination
include: fencing, regrading, and planting at the northern portion of the inactive
landfill; installing a groundwater collection and treatment system (allowing some contaminants
to settle out, exposing the groundwater to air to allow organic contaminants to evaporate,
and recapturing the contaminants in a carbon filter before releasing to the air) and
discharging the treated water to Cowdery Drainage; monitoring groundwater and surface
water; and improving the landfill structure by regrading, revegetating, digging perimeter
ditches, and installing fences. The potentially responsible parties, under EPA monitoring, are
preparing the technical specifications and design for the selected cleanup technologies in two
phases. The first phase, which includes fencing, regrading, and vegetating the northern section
of the inactive landfill, was completed in 1990. An interim groundwater and surface water
monitoring program was initiated in 1991. The remaining cleanup activities are included in the
second design phase. Actual cleanup activities are scheduled to be completed in late 1993.
Site Facts: Pursuant to an Enforcement Order in 1984, Landfill, Inc. installed a pressurized
pipeline to protect drinking water supplies. The EPA negotiated Consent Decrees with the
potentially responsible parties, including the City of Boulder, Landfill, Inc., and the Cowdery
Company, for performance of the response actions.
Environmental Progress
Protective measures have been taken to ensure the safety of the local drinking water supply
and a fence has been constructed to restrict access and prevent further degradation of the
site. These actions have reduced the potential for exposure to site contamination while the
permanent groundwater treatment system is being designed and constructed.
Site Repository
Louisville Library, 950 Spruce Street, Louisville, CO 80027
MARSHALL LANDFILL 29 March 1992
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ROCKY FL
PLANT (USD
COLORADO
EPA ID # CO7890010526
EPA REGION 8
Jefferson County
6 miles northwest of Denver
Site Description
The Rocky Flats Plant site covers 6,500 acres of United States Department of Energy
(USDOE) land. Originally established by the Federal government in 1951, the facility
currently is under contractor management. Rocky Flats has produced plutonium triggers for
the USDOE nuclear weapons programs. Site operations include recovery and reprocessing of
plutonium from old weapons and manufacturing residues, laboratory research, and the
manufacture of "high-tech" metals, many of which continue to generate a variety of waste
streams on site. Many of the manufacturing and pollution control facilities that originally
operated at the site have been upgraded from their original construction and have been used
in the USDOE's nuclear weapons production program. Since a 1989 FBI raid, plutonium
operations have been suspended pending the correction of the identified problems. Although
a phased restart of operations was planned for late 1991, as of early 1992, Rocky Flats Plant
has no production mission. Site contaminants have spilled onto the ground and into water
supply drainages. The USDOE identified over 2,000 waste streams that the production
processes generated at the site. Other major environmental concerns at the site encompass
178 disposal areas resulting from past waste management practices including a series of
evaporation surface impoundments, old process pipelines and underground tanks, an aqueous
spray irrigation field, two on-site landfills, leaking drum storage areas, and several disposal
trenches. Approximately 9,500 people live within a 5-mile radius of the industrial complex.
Site Responsibility: This site is being addressed through
Federal and State actions.
NPL USTING HISTORY
Proposed Date: 10/15/84
Final Date: 10/04/89
Threats and Contaminants
Air is a potential contaminant pathway for migration of radioactive plutonium,
uranium, and americium. Groundwater contains various volatile organic compounds
(VOCs), radionuclides, and heavy metals. Soil and surface water are contaminated
with plutonium, uranium, and americium. Touching, inhaling, or ingesting
contaminants in soil, air, groundwater, and surface water and could pose a health
threat. Shallow groundwater in the southern section of the site (the Hillside area)
is contaminated with high levels of VOCs.
30
March 1992
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Cleanup Approach
This site is being addressed in multiple stages: immediate actions and a total of 15 long-term
remedial phases focusing on the Hillside Areas; the 903 Pad Area, East Trenches, and
Mound Areas; Off-site Releases; Solar Ponds; Woman Creek; Walnut Creek; Present
Landfill; 700 Area; Original Process Waste Lines; Other Outside Closures; West Spray Field;
400/800 Area; 100 Area; Radioactive Sites; and Inside Building Closures.
Response Action Status
Immediate Actions: In 1987, the USDOE removed more than 20,000 cubic
yards of sludge from evaporation ponds.
Hillside Areas: In 1988, the USDOE completed draft reports on the nature and
extent of contamination activities within the Hillside 881 area. Construction has
begun on interim cleanup activities that are intended to stop contaminants from
moving through the groundwater through the use of a french drain collection system and
associated treatment plant. Investigations are continuing in the area and include additional
drilling and sampling of soil, water, air and biota. The USDOE began treating the
groundwater in early 1992.
903 Pad, East Trenches, and Mound Areas: This area may be the most
complex and difficult to address on the site due primarily to the high
concentrations of radioactive contaminants that must be cleaned up, as well as
surface water seeps, which have required interim measures. An interim remedy was selected
in early 1991 and consisted of a surface water collection and treatment system, which is under
construction. Additional sampling and analysis began in mid-1991 on soil, sediments, water,
and biota. A second interim measure is being developed to address potential releases from
this area of the site to an adjacent drainage.
Off-site Releases: These areas consist of: two reservoirs used for irrigation and
as drinking water supplies for approximately 250,000 people, a third irrigation
reservoir, and land used for recreational purposes. The USDOE conducted two
preliminary risk studies that have been used as a focus for an investigation of these areas. An
investigation work plan was submitted in mid-1991 and has been approved.
Solar Ponds: In 1991, an interim remedy was selected by the USDOE to
operate a groundwater collection system to cleanup the solar ponds. The
groundwater collection system includes the following: installation of evaporators
which will be used to still the water within the pond and the water leading downgradient from
the pond; building large tanks to equalize the water flow into the evaporators; and the water
condensation to be forwarded to the process water. The USDOE issued an interim response
action decision document for public comment, in order to complete the dewatering of the
solar ponds. Construction of the groundwater collection system is expected to be completed in
1992. A work plan for a further site-wide investigation of the area was prepared and has been
approved. Additional remedies and cleanup activities are expected to take place in the near
future.
ROCKY FLATS PLANT (USDOE) 31 March 1992
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Woman Creek: This area encompasses the stream, two ponds on the stream,
and a number of disposal sites within the basin including an abandoned landfill,
disposal trenches, and former waste storage areas. The drainage basin receives
surface water flows and groundwater seepage from contaminated and active industrial areas
of the site, which potentially may affect downstream surface water supplies. A draft
investigation work plan has been submitted and approved. Investigative field work is
expected to begin in mid-1992.
Walnut Creek: The Walnut Creek Area encompasses the stream, numerous
ponds, disposal trenches and surface impoundments, and former waste storage
areas. The drainage basin receives surface water flows and groundwater seepage
from contaminated and active industrial areas of the site, which potentially may affect down
stream surface water supplies. A draft work plan for an investigation has been submitted and
approved. Investigative field work began in 1991.
Present Landfill: This area of the site comprises a large, active landfill that has
been in use for over 20 years. It once was enclosed by a groundwater diversion
and seepage collection system, but the system has since been abandoned and is
partially destroyed. A work plan for the investigation of this area has undergone revisions and
has been approved.
Original Process Waste Lines (OPWL): This area consists of an underground
network of old process waste lines that were used to pipe wastes to the surface
impoundments or discharge points. A preliminary work plan for an investigation
of these poorly mapped lines was submitted and has been approved.
Other Areas: Eight separate investigations will be conducted to determine the
nature and extent of contamination. These areas include the 700 Area, Other
Outside Closures, West Spray Field, 400/800 Area, 100 Area, Radioactive Sites,
Inside Building Closures, and Low Priority Sites. Workplans are in various stages of
development for these areas.
Site Facts: The EPA, the USDOE, and the State signed an Interagency Agreement in early
1991. The agreement outlines procedures and schedules for investigations of the 16 long-term
cleanup phases. In 1991, a Federal Facility Compliance Agreement was signed to achieve
compliance with land disposal restrictions. In 1992, an amendment was signed extending the
provisions of the Federal Facility Compliance Agreement to Third Land Disposal Restrictions
Mixed Wastes.
Environmental Progress
Numerous actions and investigations currently are underway at the Rocky Flats Plant. The
removal of contaminated sludge from solar ponds and the dewatering operation are intended
to contain the spread of contaminants. The construction for the cleanup of contaminated
groundwater resources at the site has begun, and further cleanup activities are planned that
March 1992 32 ROCKY FLATS PLANT (USDOE)
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Site Repository
Front Range Community College Library, Public Reading Room, 3645 West 112th Avenue,
Westminster, CO 80030
ROCKY FLATS PLANT (USDOE)
33
March 1992
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ROCKY MO
ARSENAL
COLORADO
EPAID#CO521002076J
EPA REGION 8
Adams County
niles northeast of downtown Denver
Other Names:
Shell Chemical Company
Site Description
The 17,000-acre Rocky Mountain Arsenal site is a facility owned and operated by the U.S.
Army. Hazardous wastes have been deposited on 1,750 acres of the site. The facility was
established in 1942 and has been used by both government and industry to manufacture, test,
package, and dispose of various chemical products, chemical warfare agents, and munitions
including rocket fuels, herbicides, pesticides, nerve gases, mustards, and incendiary munitions.
In 1947, portions of the site were leased to a chemical manufacturing company, Colorado
Fuel and Iron Corporation, for the manufacture of chlorinated benzenes and the pesticide
DDT. Shell Chemical Company later assumed the pesticide and herbicide manufacturing
operations. Industrial effluents generated at the arsenal routinely were discharged to unlined
evaporation basins. Solid wastes were buried at various locations. Spills of raw materials and
final products occurred within the manufacturing complexes. Munitions and pesticide
operations over 40 years led to spills and the disposal of more than 750 different hazardous
wastes in several areas. All production operations ceased at the site in 1982. Investigations by
the Army have identified at least 178 on-post areas as being potentially contaminated with
hazardous wastes. Basin F, which is closed, formerly held as much as 240 million gallons of
liquid wastes. It now holds about 10 million gallons in three lined tanks and a double-lined
surface impoundment, and 564,000 cubic yards of solids in a double-lined, capped waste pile.
Five unlined basins received wastes before Basin F was built. The site also contains an
incinerator; processing, storage, and supporting operations; and two major industrial
complexes that produced pesticides, nerve gas, and mustard gas. There are numerous waste
piles, burial trenches, and abandoned munitions storage areas on site. On-site groundwater,
which currently is not being used, is contaminated in both the shallow and deep aquifers. Old
livestock wells on site are being plugged and abandoned. Seven groundwater intercept systems
have been installed to remove the contaminants. Three plumes of contaminated groundwater
migrated off site before the intercept systems were installed. Surface streams near the arsenal
may be receiving contaminants from groundwater discharge. Plumes of contaminated
groundwater eventually discharge into the South Platte River. Stapleton Airport abuts the
southwest corner of the site. The South Adams County Water and Sanitation District
(SACWSD) was created in 1953 to supply approximately 30,000 customers with well water
from the aquifers.
Site Responsibility: This site is being addressed through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 10/15/84
Final Date: 07/22/87
34
March 1992
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Threats and Contaminants
T
On-site groundwater is contaminated with various volatile organic compounds
(VOCs). Sediment samples from lakes and drainage areas are contaminated with
VOCs, heavy metals, and pesticide residuals. Soils are contaminated with heavy
metals including arsenic, lead, and mercury; pesticides; VOCs and breakdown
products from warfare agents. The health threats associated with this site include
inhaling contaminated dusts that result from cleanup activities, touching or ingesting
contaminated soils, and eating contaminated plants and animals. Homes affected by
contaminated drinking water were supplied with alternate water.
Cleanup Approach
This site is being addressed in eighteen stages: initial actions and seventeen long-term
remedial phases focusing on the contamination areas identified at the site.
Response Action Status
Initial Actions: Shell Chemical Company installed the Irondale groundwater
treatment system in 1981. The installation of the North Boundary groundwater
treatment system was completed in 1982. Liquids were evaporated and the
contaminated sewer was removed from Basin F in 1982. In 1984, the Northwest Boundary
groundwater treatment system was completed. Over 76,000 drums of waste salts were
removed in 1986. A 12,045-foot-deep hazardous waste injection well was closed in 1986.
South Adams County Public Water Supply: The EPA connected
approximately 400 private drinking water wells to a temporary granular activated
carbon water treatment system in 1986. Located adjacent to the arsenal, a
permanent water treatment system was constructed and began operating in 1989 as the Klein
Water Treatment Plant, supplying 30,000 people in the SACWSD with treated water.
M-1 Ponds and Rail Classification Yard: Currently the M-l Ponds
vitrification system is being designed and is expected to be completed in 1992.
Construction has been completed and operation and maintenance has begun for
the Motor Pool Area vapor extraction system and the Lime Settling Basins containment
system. These cleanup activities are expected to be completed in 1992. Workers have
completed activities at the Rail Classification Yard which involved the treatment of
contaminated groundwater through an intercept and treatment system.
Basin F and Basin A: The groundwater intercept and treatment systems north
of Basin F and Basin A Neck were constructed in 1990. The following cleanup
activities currently are underway: disposal of liquid wastes at the hydazine facility
and cleanup/dismantling of the facility; and sanitary sewer closure. The reapplication of the
wind-blown dust control was completed in 1988 and asbestos was removed in 1989.
ROCKY MOUNTAIN ARSENAL 35 March 1992
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Aquifers: The investigation determining the nature and extent of contamination of
an off-site area, south of 86th Avenue, affecting the SACWSD continues under the
jurisdiction of the Chemical Sales Company NPL Site.
Site Contamination: On-site and off-site studies are investigating the type and
extent of contamination. The investigations will include alternatives for final
cleanup and are scheduled for completion in 1994 and 1992, respectively.
Groundwater Intercept and Treatment System: The technical specifications
for the groundwater intercept and treatment system off site, to the north of the
arsenal, were completed in 1991. Construction is underway and is expected to be
completed in late 1992.
North Boundary System: Recharge trenches were installed at the North
Boundary System. The first stage of improvements were made to the system in
1988, and the second stage improvements were completed in 1990. Engineering
design for two new intercept and treatment systems, Basin F and Basin A, and one new
system located off-site, north of the Arsenal, also were completed in 1989.
Abandoned Wells: A total of 353 abandoned wells on post were sampled, and
properly closed and plugged in 1990.
Contaminated Liquids and Sludges From Under Basin F: Basin F was
closed in 1989. Approximately 10 1/2 million gallons of liquid and 564,000 cubic
yards of contaminated sludges have been removed and placed in temporary storage.
Contaminated Liquids in the Building 1727 Sump: The operations and
maintenance of the sump are expected to continue through 1993.
Wastewater: The design and construction of a water treatment plant to treat
wastewater resulting from other cleanup actions will began in 1991. Operation of
the wastewater treatment plant began in late 1992 and is expected to have fully
treated wastewater by the end of the year.
South Tank Farm: In 1991, remedies were selected to cleanup the South Tank
Farm plume. The South Tank Farm Plume is being monitored to delineate plume
movement and natural biodegradation. Currently, cleanup activities are underway
and are expected to be completed in 1993.
Army Trenches: A monitoring plan is ongoing and is re-evaluated annually to
determine if further action is necessary at the Army trenches.
Shell Trenches: Construction of the containment system, which consisted of a
slurry wall and cap, was completed in 1991.
March 1992 36 ROCKY MOUNTAIN ARSENAL
-------
Northwest Boundary System: Improvements to the Northwest Boundary
system are ongoing, and the first stage was completed in 1991. Monitoring of
approaching plumes is being conducted. Contaminants are being captured and
treated by a groundwater intercept and treatment system.
Treatment of Basin F Liquids: Construction of the incinerator for the
treatment of the liquids began in 1991. Metals in incineration residues will be
recycled and the remaining liquids will be disposed of off site. The incinerator is
scheduled to begin operation in 1992. The selected cleanup technologies used to treat the
contaminated groundwater include construction of a granular activated carbon water
treatment system, regeneration of spent carbon at an off-site location, and modification of
the system to include an air stripping facility to treat vinyl chloride. Combustion residues will
be disposed of off-site and will include recovery of metals. Well pumps and motors,
transmission piping, and laboratory and office space will be constructed at the site to ensure
that the remedy operates effectively.
Chemical Process Related Activities: Cleanup activities which entail ongoing
sampling and decontamination of agent related equipment, piping, and containers
began at this area in 1991.
Site Facts: In 1982, the EPA initiated a Memorandum of Agreement with the Army, the
State, and Shell Chemical Company, a potentially responsible party, requiring the exchange of
information and participation in the development and implementation of response actions at
the arsenal. In 1989, Shell, the Army, the Department of Interior, the Agency for Toxic
Substances and Disease Registry, the Department of Justice, and the EPA signed a Federal
Facility Agreement. The new agreement superseded the Memorandum of Agreement,
apportioned liability between Shell and the Army, and resolved the Army-Shell litigation.
Congress is considering legislation to make the arsenal a National Wildlife Refuge.
Environmental Progress
Numerous initial and long-term cleanup actions have been performed at the Rocky Mountain
Arsenal site. The closing of the site, removal of contaminants, and the provision of an
alternative water supply have reduced the potential for exposure to contaminated materials at
the site. Further studies and cleanup actions are being performed that will continue to reduce
contamination levels and to identify final cleanup remedies for the diverse site contamination
areas.
Site Repository
Denver Public Library, Central Library, 1357 Broadway, Denver, CO 80203
ROCKY MOUNTAIN ARSENAL 37 March 1992
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SAND CREEK
INDUSTRIAL
COLORADO
EPA ID# COD980717953
EPA REGION 8
Adams County
Commerce City
Other Name*:
L C Corporation
ado Organic Chemical Company
Holly & 48th SL Landfill
Browning Ferris/Globe Chemical
Colorado International Corporation
Private Brand* Western, Inc.
Site Description
The 500-acre Sand Creek Industrial site consists of four known sources of contamination, all
currently inactive: the Oriental Refinery, the Colorado Organic Chemical (COC) property,
the L.C. Corporation acid pits, and the 48th Street and Holly Landfill. The site's 25-year
history includes a fire that destroyed the refinery; a major spill of refined petroleum; two
methane explosions which killed two men and injured others; an incident in which livestock
were severely burned when they wandered into acid pits; and a fire at the pesticide
formulator that released fumes over northeast Denver and resulted in several firemen being
hospitalized. The Oriental Refinery is a former oil refinery and consists mostly of rubble. The
site now is occupied by a propane distributing firm and a gas station. The COC plant
originally manufactured pesticides in the 1960s. Since 1968, when a fire destroyed three of
the buildings on site, several health agencies have found unacceptable conditions at the plant.
These have included unsatisfactory waste management practices and worker safety conditions,
violations in storage and handling of flammable liquids, and soil containing high levels of
pesticides and other chemicals. A second fire occurred at the plant in 1977. The L.C.
Corporation hauled and disposed of approximately 8,000 tons of acid waste in pits. Lime was
added to neutralize the acid and the pit area was covered. Acid was found to be seeping from
the pits into Sand Creek in 1976. In 1980, the L.C. Corporation covered the seepage with
clean soil. The 48th Street and Holly Landfill was used to dispose of municipal wastes. Less
than 25 people live within 1/2 mile of the site; however, hundreds of people work in the area.
Site Responsibility: This site is being addressed through
Federal and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date: 12/30/82
Final Date: 09/08/83
38
March 1992
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Threats and Contaminants
Groundwater contaminants include various volatile organic compounds (VOCs), as
well as the heavy metals cadmium, nickel, and arsenic. Soil is contaminated with
VOCs, pesticides, herbicides, and arsenic. Sand Creek is polluted with heavy metals
including cadmium, nickel, and arsenic. Those who accidentally come in contact
with or ingest contaminated groundwater, surface water, or soil may suffer adverse
health effects. In addition, individuals on site may be exposed by inhaling
contaminated dust or vapors from the soil.
Cleanup Approach
This site is being addressed in seven stages: initial actions and six long-term remedial phases
focusing on cleanup of COC subsurface soils and structures, COC surface soils, L.C.
Corporation acid pits, 48th Street and Holly Landfill, groundwater contamination, and gas at
the Holly Landfill.
Response Action Status
Initial Actions: In 1984, COC removed waste drums and contaminated soil and
fenced the area. In 1988, the EPA removed two tanks and five drums containing
pesticides and transported them to federally approved facilities. In addition, a
synthetic cover was placed over the contaminated soil to prevent erosion and vapor emissions.
The potentially responsible parties installed a methane gas collection and treatment system at
the Holly Landfill in late 1991.
COC Subsurface Soils and Structures: In 1989, the EPA selected a remedy
to clean up the COC subsurface soils and structures by: excavating the
contaminated soil and incinerating it off site, extracting the VOCs from the
subsurface soil with a vacuum extraction system, demolishing the contaminated tanks and
buildings and disposing of them in a federally approved facility, and treating 38,000 cubic
yards of subsurface soil by either biological treatment or soil washing. The engineering design
of the selected remedy has been completed. Cleanup activities have been underway since late
1990 and are expected to be completed in late 1994.
COC Surface Soils: In 1990, the EPA selected a remedy to clean up COC
surface soils by soil washing and incinerating of soil wash residues. Washed soils
will be replaced and covered on the site. As part of the engineering design of this
cleanup remedy, the EPA is conducting pilot tests to refine the soil washing process. The
design phase is expected to be completed in late 1992.
LC. Corporation Acids Pits: In 1992, the EPA is scheduled to complete studies
on the type and extent of acid contamination in the pits and the surrounding area.
SAND CREEK INDUSTRIAL 39 March 1992
-------
48th Street and Holly Landfill: The EPA is conducting an investigation to
determine the extent of the contaminants in the 48th Street and Holly Landfill and
to identify alternative technologies to clean up the area. Investigations are also
underway to reduce the gas emissions emanating from the Holly Landfill. This study is
expected to be completed in 1992.
Groundwater: In 1992, the EPA initiated extensive studies of the groundwater in
the area to determine if there is a need for groundwater cleanup activities. These
studies are expected to be completed in 1993.
Gas at Landfill: In 1990, the EPA began investigating methods to reduce the
gas emissions emanating from the Holly Landfill. The investigation is schedule to
be completed in late 1992.
Site Facts: In 1984, the EPA issued an Administrative Order to COC to remove waste
drums and contaminated soil and to fence the area.
Environmental Progress
The removal of drums and contaminated soil and the fencing of the area, in addition to early
actions taken by the site owners, have reduced the potential for exposure to contaminated
materials at the Sand Creek Industrial site while further investigations and cleanup activities
are on-going.
Site Repository
Adams County Public Library, Commerce City Branch, 7185 Monaco Street, Commerce City,
CO 80022
March 1992
40
SAND CREEK INDUSTRIAL
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SMELTERTOWN7
COLORADO
EPA ID# COD983769738^
EPA REGION 8
Chaffee County
Near Salida
Site Description
Smeltertown site is a 100-acre site in a rural area near Salida, Colorado. Koppers, Inc.,
CoZinCo, Inc., and a smelter company all conducted operations on this property which is
owned by Butala Construction Company. The smelter operated from 1902 to 1920 removing
molten slag from the furnaces and dumping it down a bluff toward the Arkansas River.
Koppers treated railroad ties on the site from 1926 to 1946. When the surface soil became
saturated with creosote dripping from the ties, a layer of sand was added and operations
continued. Butala Construction Company scraped the soils into a pile to make room for
gravel mining operations. CoZinCo has processed zinc sulfate and smelter slag on the site
since 1977. According to a 1987 EPA report, soil on the property contains elevated levels of
heavy metals. Contaminants were found in three drum storage areas, two ponds used to hold
spent processing water, a pile consisting of sludge scraped from the ponds, and an area where
sludge was worked into the soil. Shallow soil in the smelter area is also contaminated from
smelter stack emissions and spilled ore. A 1988 EPA report found groundwater to be
contaminated with heavy metals and creosote constituents. The report also documented
metals and creosote constituents in the air, and metals in the Arkansas River downstream of
where Kimmet Spring discharges into the river. An estimated 3,700 people obtain drinking
water from public and private wells and springs within 4 miles of the site; the nearest well is
approximately 1,000 feet from the site. Approximately 5,200 people live within 4 miles of the
site. Two recreation areas are nearby and the river is used for fishing.
Site Responsibility: This site is being addressed through
Federal actions.
NPL LISTING HISTORY
Proposed Date: 02/07/92
Threats and Contaminants
The air is contaminated with heavy metals and creosote. On-site soil contains
elevated levels of heavy metals, including chromium, lead, zinc, and, nickel. On-site
groundwater is contaminated with heavy metals including zinc, barium, and
manganese and creosote constituents. The Arkansas River is contaminated with
metals. Butala Construction Company workers are at risk of being exposed to
contaminated soil on the site. Since the site is accessible, the 200 people living
within 1 mile of the site also may be exposed.
41
March 1992
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Cleanup Approach
This site is being addressed in one long-term remedial phase focusing on cleanup of the
entire site.
Response Action Status
Entire Site: The EPA is planning an investigation of the nature and extent of
contamination at the site. This investigation is scheduled to begin in 1992 and will
help determine the best alternative for cleanup at the site.
Environmental Progress
The EPA holds that no immediate threats for human health and the environment exist while
further studies are taking place.
Site Repository
Not established.
March 1992
42
SMELTERTOWN
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SMUGGLER
MOUNTAIN
COLORADO
EPA ID# COD98080627
EPA REGION 8
Pitkin County
In the northeast comer of
the City of Aspen
Site Description
The 116-acre Smuggler Mountain site is an inactive silver and lead mining site that was in
operation from 1879 to 1918. Waste rock and mine tailings from mills and mines in the area
have been deposited between the Roaring Fork River and the steep slope that forms the
western side of Smuggler Mountain. Most of the mines are abandoned, but limited mineral
exploration activities are still conducted on site. Tailings and mine wastes were mixed with
native soil, and spread across the site. The total volume of mine waste material has been
estimated at 1,300,000 cubic yards. In many cases, development in the Aspen area has taken
place directly over waste piles, or mine waste has been dozed into mounds that remain as
berms of contaminated soil. Contaminated soil has also been used as fill material in some
areas. The site is situated in a residential area in the northeastern portion of the City of
Aspen. The City has a year-round population of approximately 4,500 people, as well as
substantial seasonal visitors. The City of Aspen obtains its drinking water from the Roaring
Fork River, approximately 1,000 feet downstream from the site.
Site Responsibility: The site is being cleaned up through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 10/15/84
Final Date: 06/01/86
Threats and Contaminants
Soil is contaminated with heavy metals including lead, cadmium, and arsenic. The
potential health threats to area residents include accidentally ingesting
contaminated surface soils or eating vegetables grown in contaminated soils. The
Roaring Fork River is not contaminated by the site, and thus is not considered a
potential health risk to the residents of Aspen.
43
March 1992
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Cleanup Approach
This site is being addressed in three stages: immediate actions and two long-term remedial
phases focusing on cleanup of the residential areas and cleanup of the mine area.
Response Action Status
Immediate Actions: In 1985, a party potentially responsible for site
contamination installed fencing around portions of the site and posted warning
signs, as directed by the EPA. In 1990, the EPA excavated, recontoured, and
capped contaminated soil on two residential properties as a demonstration project.
Residential Areas: The remedy selected by the EPA in 1990 addresses the
impact of contamination on residential areas within the site including:
constructing two cells for on-site disposal of waste materials and relocating an
irrigation pipeline that passes through the Mollie Gibson Park repository; excavating one foot
of contaminated soil in areas with high lead concentrations, laying a geo-textile liner,
backfilling with clean fill, covering with topsoil, and revegetating; and placing institutional
controls to ensure the integrity of the remedy within the residential areas. The EPA is
currently conducting a lead speciation and bioavailability study to define risk further. The
design phase is scheduled to be completed in 1992.
Mine Area: The EPA is expected to begin a study of the nature and extent of
contamination at the Smuggler-Durant Mine area, including possible
contamination of groundwater underlying the site, in 1992. The study will define
the contaminants and recommend alternatives for final cleanup.
Site Facts: In 1985, the EPA issued three Administrative Orders to the potentially
responsible parties. The orders required the property owners to notify the EPA of any plans
to move soils or mining wastes on the site, investigate site contamination, recommend
alternatives for final cleanup, and provide for the fencing and securing of a portion of the site
to prevent public access.
Environmental Progress
Initial actions such as fencing portions of the Smuggler Mountain site and excavating,
removing, and capping contaminated soil in other areas have reduced the threat of direct
contact with contaminants while investigations and design activities take place.
Site Repository
Pitkin County Library, 120 East Main Street, Aspen, CO 81611
March 1992 44 SMUGGLER MOUNTAIN
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URAVAN URANIOM
PROJECT (U
CARBIDE
CORP.)
COLORADO
EPA ID# COD007063274
Site Description
FGPA REGION 8
Montrose County
90 miles southwest
of Grand Junction
Other Names:
avajn Uranium Mill Operations
Urtvan Uranium Mill Town
UMETCO
The Uravan Uranium site began as a radium recovery plant in 1915. The plant was expanded
to include vanadium recovery in 1935 and began this process in 1936. The plant operated
from the late 1940s as a uranium processing facility. In 1984, Union Carbide formed a
wholly-owned subsidiary, UMETCO, which now owns and operates the facility. During the
history of operations at the site, a large volume of waste products, including raffinates (liquid
wastes from the uranium processing operations), mine tailings, and raffinate crystals from the
various processes were disposed of on site. Radon gas emanates from the eroding tailings
piles. Uravan is one of the more complex radiation sites in the country, with heavy metals,
residual salts, and radionuclide contamination of groundwater and surface water. The Town
of Uravan, established in 1935 to house the workers at the mill and mine facilities, no longer
exists.
Site Responsibility:
This site is being addressed through
Federal, State, and potentially
responsible parties' actions.
NPL USTING HISTORY
Proposed Date: 10/15/84
Final Date: 06/10/86
Threats and Contaminants
ZEJ
Air at the site contains elevated levels of radon gas. Soil, groundwater, and the
San Miguel River contain radionuclides and heavy metals. Before the town was
evacuated and torn down, potential exposure to radionuclides posed a threat to
human health.
45
March 1992
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Cleanup Approach
This site is being addressed in a single long-term remedial phase focusing on cleanup of the
entire site.
Response Action Status
Entire Site: The State completed a plan to clean up contamination at the site in
1986, and reached an agreement with Union Carbide over their performance of
the cleanup actions. The features of the remedy include: reclaiming nearly 10
million cubic yards of radioactive tailings by capping and revegetating; constructing a disposal
system for radioactive crystals; placing 1 1/2 million cubic yards of waste found along the San
Miguel River in a secure disposal area; excavating contaminated soil and placing it in an
approved landfill; and reclaiming and revegetating the land on the site. The major elements
of these activities are underway and are scheduled to be completed by 1995. Most of the 10
million cubic yards of tailings have been placed in a secured disposal area and capped.
Process pond water and seep water now are collected and evaporated in lined ponds.
Approximately 400,000 cubic yards of pond crystals have been deposited in a clay-lined
repository. Union Carbide has finished constructing two lined evaporation ponds adjacent to
the state highway. The State installed pumps and is pumping the old, unlined tailings ponds
for mill raffinate and sending the recovered wastewater to the new lined ponds. The State
also is conducting radiation surveys of the old pond area to address issues that affect the
health of workers on site before they dewater the raffinate crystals from the old ponds.
Site Facts: The EPA entered into a Memorandum of Agreement (MOA) with the State in
1986 to avoid duplicating efforts. The MOA designated the State as the acting lead agency
and required the State to consult with the EPA on all actions taken at the site as well as find
an effective remedy for the problems there.
Environmental Progress
After adding this site to the NPL, the EPA performed preliminary investigations and
determined that, because the town surrounding the site has been evacuated and torn down,
no immediate actions were required at the Uravan Uranium site. Cleanup actions presently
completed or underway will restore the site to safety levels that are protective of human
health and the surrounding environment.
Site Repository
Colorado State Health Department, Radiation Control Division, 3773 Cherry Creek Drive,
North Denver, CO 80231
March 1992 46 URAVAN URANIUM PROJECT
(UNION CARBIDE CORP.)
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WOODBURY
CHEMICAL
COMPANY
COLORADO
EPA ID# COD980667075
EPA REGION 8
Adams County
Commerce City
Site Description
The 11-acre Woodbury Chemical Company site began operations in the 1950s as a pesticide
formulation plant. The plant burned down in 1965, and the fire debris and rubble, including
water-soaked bags of pesticides and contaminated soils, were moved to an adjacent lot. Over
1,500 pounds of pesticides were placed on the lot. The plant was rebuilt in the original
location and continued operations until 1971. Various pesticides and volatile organic
chemicals (VOCs) were produced or used on the site during its period of operation. The site
is surrounded by industry, and approximately 3,000 people live within 1/2 mile of the site.
Site Responsibility:
This site is being addressed through
Federal and potentially responsible
parties' actions.
NPL USTING HISTORY
Proposed Date: 07/23/82
Final Date: 09/08/83
Threats and Contaminants
Sediments in a drainage ditch, surface water runoff, and soils on the site contained
chlorinated pesticides and heavy metals. Potential health risks may have existed for
individuals who accidentally ingested or had contact with contaminated soils or
surface water.
Cleanup Approach
This site is being addressed in three stages: immediate actions and two long-term remedial
phases focusing on cleanup of the rubble piles and removal of contaminated soils on the
entire site.
47
March 1992
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Response Action Status
Immediate Actions: In 1983, to prevent public access to the site and to help
stabilize the contamination, the EPA posted warning signs, installed a fence
around the site, and graded the site to prevent additional surface water runoff.
Rubble Piles: In 1985, the EPA selected a complete cleanup remedy for the
original site that involved a combination of off-site landfilling and incineration of
soil and rubble. During design of this remedy in 1986, the EPA discovered that site
contamination extended farther off site than was originally believed. This led to the addition
of another cleanup area to the site. All contaminated soil, originally meant to be addressed in
this cleanup action, were addressed in the next phase. Actual cleanup activities were
completed in 1992.
Soils: In 1989, the EPA selected a remedy for cleanup of the remainder of the
site, which included off-site incineration of up to 2,000 cubic yards of highly
contaminated soils and placement of 10,600 cubic yards of soils above the cleanup
levels in an off-site federally approved landfill. The design of the cleanup technologies began
in 1990 and was completed in 1991. This work was completed in 1992 by the parties
potentially responsible for site contamination under EPA monitoring.
Site Facts: An Administrative Order on Consent was signed in 1987 between the EPA and
the McKesson Corporation to conduct an investigation into the contamination at the site and
to identify alternative technologies for the cleanup. A Consent Decree was signed in 1990
between the EPA, the McKesson Corporation, and Farmland Industries. This decree covered
cleanup and past costs associated with the study and cleanup design for the site. A separate
Consent Decree was completed in 1991 between the EPA and Maytag for collection of a
portion of the past costs.
Environmental Progress
The actions to prevent access to the site and to prevent additional surface water runoff
eliminated the potential for exposure to contaminated materials at the Woodbury Chemical
Company site while cleanup of the rubble and soils at the entire site were completed.
Concentrations have been reduced to health-based levels throughout the site to industrial use
exposures. The EPA is in the process of deleting this site from the NPL.
Site Repository
Adams County Public Library, Commerce City Branch, 7185 Monaco Street, Commerce City,
CO 80022
March 1992 48 WOODBURY CHEMICAL COMPANY
-------
GLOSSARY
Terms Used in the NPL Book
This glossary defines terms used throughout the NPL Volumes. The terms and
abbreviations contained in this glossary apply specifically to work performed
under the Superfund program in the context of hazardous waste management. These
terms may have other meanings when used in a different context. A table of common
toxic chemicals found at NPL sites, their sources, and their potential threats is located
onpageG-15
Acids: Substances, characterized by low pH
(less than 7.0), that are used in chemical manu-
facturing. Acids in high concentration can be
very corrosive and react with many inorganic
and organic substances. These reactions possi-
bly may create toxic compounds or release
heavy metal contaminants that remain in the
environment long after the acid is neutralized.
Administrative Order On Consent: A
legal and enforceable agreement between the
EPA and the parties potentially responsible for
site contamination. Under the terms of the
Order, the potentially responsible parties (PRPs)
agree to perform or pay for site studies or
cleanups. It also describes the oversight rules,
responsibilities, and enforcement options that
the government may exercise in the event of
non-compliance by potentially responsible
parties. This Order is signed by PRPs and the
government; it does not require approval by a
judge.
Administrative Order [Unilateral]: A
legally binding document issued by the EPA,
directing the parties potentially responsible to
perform site cleanups or studies (generally, the
EPA does not issue Unilateral Orders for site
studies). This type of Order is not signed by the
PRPs and does not require approval by a judge.
Aeration: A process that promotes breakdown
of contaminants in soil or water by exposing
them to air.
Agency for Toxic Substances and Dis-
ease Registry (ATSDR): The Federal
agency within the U.S. Public Health Service
charged with carrying out the health-related
responsibilities of CERCLA.
Air Stripping: A process whereby volatile
organic chemicals (VOCs) are removed from
contaminated material by forcing a stream of air
through the contaminated material in a pressur-
ized vessel. The contaminants are evaporated
into the air stream. The air may be further
treated before it is released into the atmosphere.
Ambient Air: Any unconfined part of the
atmosphere. Refers to the air that may be
inhaled by workers or residents in the vicinity of
contaminated air sources.
Applicable or Relevant and Appropriate
Requirements (ARARs): Federal, State, or
local laws which apply to Superfund activities at
NPL sites. Both emergency and long-term
actions must comply with these laws or provide
sound reasons for allowing a waiver. ARARs
must be identified for each site relative to the
characteristics of the site, the substances found
at the site, or the cleanup alternatives being
considered for the site.
G-1
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GLOSSARY
Aquifer: An underground layer of rock, sand,
or gravel capable of storing water within cracks
and pore spaces, or between grains. When
water contained within an aquifer is of sufficient
quantity and quality, it can be tapped and used
for drinking or other purposes. The water
contained in the aquifer is called groundwater.
A "sole source aquifer" supplies 50 percent or
more of the drinking water of an area.
Artesian (Well): A well made by drilling into
the earth until water is reached, which, due to
internal pressure, flows up like a fountain.
Asbestos: A mineral fiber that can pollute air
or water and is known to cause cancer or
asbestosis when inhaled.
Attenuation: The naturally occurring process
by which a compound is reduced in concentra-
tion over time through adsorption, degradation,
dilution, or transformation.
Background Level: The amount of a sub-
stance typically found in the air, water, or soil
from natural, as opposed to human, sources.
Baghouse Dust: Dust accumulated in
removing particulates from the air by passing it
through cloth bags in an enclosure.
Bases: Substances characterized by high pH
(greater than 7.0), which tend to be corrosive in
chemical reactions. When bases are mixed with
acids, they neutralize each other, forming salts.
Berm: A ledge, wall, or a mound of earth used
to prevent the migration of contaminants.
Bioaccumulate: The process by which some
contaminants or toxic chemicals gradually
collect and increase in concentration in living
tissue, such as in plants, fish, or people, as they
breathe contaminated air, drink contaminated
water, or eat contaminated food.
Biological Treatment: The use of bacteria
or other microbial organisms to break down
toxic organic materials into carbon dioxide and
water.
Bioremediation: A cleanup process using
naturally occurring or specially cultivated
microorganisms to digest contaminants and
break them down into non-hazardous compo-
nents.
Bog: A type of wetland that is covered with
peat moss deposits. Bogs depend primarily on
moisture from the air for their water source, are
usually acidic, and are rich in plant residue [see
Wetland].
Boom: A floating device used to contain oil
floating on a body of water or to restrict the
potential overflow of waste liquids from
containment structures.
Borehole: A hole that is drilled into the
ground and used to sample soil or ground-water.
Borrow Pit: An excavated area where soil,
sand, or gravel has been dug up for use else-
where.
Cap: A layer of material, such as clay or a
synthetic material, used to prevent rainwater
from penetrating and spreading contaminated
materials. The surface of the cap generally is
mounded or sloped so water will drain off.
Carbon Adsorption: A treatment system in
which contaminants are removed from ground-
water and surface water by forcing water
through tanks containing activated carbon, a
specially treated material that attracts and holds
or retains contaminants.
Carbon Disulfide: A degreasing agent
formerly used extensively for parts washing.
This Compound has both inorganic and organic
G-2
-------
GLOSSARY
properties, which increase cleaning efficiency.
However, these properties also cause chemical
reactions that increase the hazard to human
health and the environment.
Carbon Treatment: [see Carbon Adsorp-
tion].
Cell: In solid waste disposal, one of a series of
holes in a landfill where waste is dumped,
compacted, and covered with layers of dirt.
CERCLA: [see Comprehensive Environmen-
tal Response, Compensation, and Liability Act].
Characterization: The sampling, monitoring,
and analysis of a site to determine the extent and
nature of toxic releases. Characterization
provides the basis for acquiring the necessary
technical information to develop, screen, ana-
lyze, and select appropriate cleanup techniques.
Chemical Fixation: The use of chemicals to
bind contaminants, thereby reducing the poten-
tial for leaching or other movement.
Chromated Copper Arsenate: An insecti-
cide/herbicide formed from salts of three toxic
metals: copper, chromium, and arsenic. This
salt is used extensively as a wood preservative
in pressure-treating operations. It is highly toxic
and water-soluble, making it a relatively mobile
contaminant in the environment
Cleanup: Actions taken to eliminate a release
or threat of release of a hazardous substance.
The term "cleanup" sometimes is used inter-
changeably with the terms remedial action,
removal action, response action, or corrective
action.
Closure: The process by which a landfill stops
accepting wastes and is shut down under Federal
guidelines that ensure the protection of the
public and the environment.
Comment Period: A specific interval during
which the public can review and comment on
various documents and EPA actions related to
site cleanup. For example, a comment period is
provided when the EPA proposes to add sites to
the NPL. Also, there is minimum 3-week
comment period for community members to
review and comment on the remedy proposed to
clean up a site.
Community Relations: The EPA effort to
establish and maintain two-way communication
with the public. The goals of community
relations programs include creating an under-
standing of EPA programs and related actions,
assuring public input into decision-making
processes related to affected communities, and
making certain that the Agency is aware of, and
responsive to, public concerns. Specific com-
munity relations activities are required in
relation to Superfund cleanup actions [see
Comment Period].
Comprehensive Environmental Re-
sponse, Compensation, and Liability
Act (CERCLA): Congress enacted the
CERCLA, known as Superfund, in 1980 to
respond directly to hazardous waste problems
that may pose a threat to the public health and
the environment. The EPA administers the
Superfund program.
Confluence: The place where two bodies of
water, such as streams or rivers, come together.
Confined Aquifer: An aquifer in which
groundwater is confined under pressure that is
significantly greater than atmospheric pressure.
G-3
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GLOSSARY
Consent Decree: A legal document, ap-
proved and issued by a judge, formalizing an
agreement between the EPA and the parties
potentially responsible for site contamination.
The decree describes cleanup actions that the
potentially responsible parties are required to
perform, or the costs incurred by the govern-
ment that the parties will reimburse, and the
roles, responsibilities, and enforcement options
that the government may exercise in the event of
non-compliance by potentially responsible
parties. If a settlement between the EPA and a
potentially responsible party includes cleanup
actions, it must be in the form of a Consent
Decree. A Consent Decree is subject to a public
comment period.
Consent Order: [see Administrative Order
on Consent].
Containment: The process of enclosing or
containing hazardous substances in a structure,
typically in a pond or a lagoon, to prevent the
migration of contaminants into the environment.
Contaminant: Any physical, chemical,
biological, or radiological material or substance
whose quantity, location, or nature produces
undesirable health or environmental effects.
Contingency Plan: A document setting
out an organized, planned, and coordinated
course of action to be followed in case of a
fire, explosion, or other accident that releases
toxic chemicals, hazardous wastes, or radioac-
tive materials into the environment.
Cooperative Agreement: A contract
between the EPA and the States, wherein a State
agrees to manage or monitor certain site cleanup
responsibilities and other activities on a cost-
sharing basis.
Cost Recovery: A legal process by which
potentially responsible parties can be required
to pay back the Superfund program for money
it spends on any cleanup actions [see Poten-
tially Responsible Parties].
Cover: Vegetation or other material placed
over a landfill or other waste material. It can
be designed to reduce movement pf water into
the waste and to prevent erosion that could
cause the movement of contaminants.
Creosotes: Chemicals used in wood pre-
serving operations and produced by distilla-
tion of tar, including polycyclic aromatic
hydrocarbons and polynuclear aromatic
hydrocarbons [see PAHs and PNAs]. Con-
taminating sediments, soils, and surface
water, creosotes may cause skin ulcerations
and cancer through prolonged exposure.
Culvert: A pipe used for drainage under a
road, railroad track, path, or through an embank-
ment.
Decommission: To revoke a license to
operate and take out of service.
Degradation: The process by which a chemi-
cal is reduced to a less complex form.
Degrease: To remove grease from wastes,
soils, or chemicals, usually using solvents.
Deletion: A site is eligible for deletion from
the NPL when Superfund response actions at the
site are complete. A site is deleted from the
NPL when a notice is published in the Federal
Register.
De minimis: This legal phrase pertains to
settlements with parties who contributed small
amounts of hazardous waste to a site. This
process allows the EPA to settle with small, or
d*> minimis contributors, as a single group rather
than as individuals, saving time, money, and
effort.
De water: To remove water from wastes, soils,
or chemicals.
G-4
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GLOSSARY
Dike: A low wall that can act as a barrier to
prevent a spill from spreading.
Dioxin: An organic chemical by-product of
pesticide manufacture which is known to be one
of the most toxic man-made chemicals.
Disposal: Final placement or destruction of
toxic, radioactive, or other wastes; surplus or
banned pesticides or other chemicals; polluted
soils; and drums containing hazardous materials.
Disposal may be accomplished through the use
of approved secure landfills, surface impound-
ments, land farming, deep well injection, or
incineration.
Downgradient: A downward hydrologic
slope that causes groundwater to move toward
lower elevations. Therefore, wells downgradi-
ent of a contaminated groundwater source are
prone to receiving pollutants.
Ecological Assessment: A study of the
impact of man-made or natural activity on living
creatures and their environment
Effluent: Wastewater, treated or untreated,
that flows out of a treatment plant, sewer, or
industrial outfall. Generally refers to wastes
discharged into surface waters.
Emission: Pollution discharged into the
atmosphere from smokestacks, other vents, and
surface areas of commercial or industrial facili-
ties.
Emulsifiers: Substances that help in mixing
materials that do not normally mix; e.g., oil and
water.
Endangerment Assessment: A study
conducted to determine the risks posed to public
health or the environment by contamination at
NPL sites. The EPA or the State conducts the
study when a legal action is to be taken to direct
the potentially responsible parties to clean up a
site or pay for the cleanup. An endangerment
assessment supplements an investigation of the
site hazards.
Enforcement: EPA, State, or local legal
actions taken against parties to facilitate
settlements; to compel compliance with laws,
rules, regulations, or agreements; or to obtain
penalties or criminal sanctions for violations.
Enforcement procedures may vary, depending
on the specific requirements of different
environmental laws and related regulatory
requirements. Under CERCLA, for example,
the EPA will seek to require potentially
responsible parties to clean up a Superfund
site or pay for the cleanup [see Cost Recov-
ery].
Erosion: The wearing away of land surface
by wind or water. Erosion occurs naturally
from weather or surface runoff, but can be
intensified by such land-related practices as
farming, residential or industrial develop-
ment, road building, or timber-cutting. Ero-
sion may spread surface contamination to off-
site locations.
Estuary (estuarine): Areas where fresh
water from rivers and salt water from
near shore ocean waters are mixed. These
areas may include bays, mouths of rivers, salt
marshes, and lagoons. These water ecosys-
tems shelter and feed marine life, birds, and
wildlife.
Evaporation Ponds: Areas where sewage
sludge or other watery wastes are dumped and
allowed to dry out.
Feasibility Study: The analysis of the
potential cleanup alternatives for a site. The
feasibility study usually starts as soon as the
remedial investigation is underway. In this
volume, the feasibility study is referred to as a
site study [see also Remedial Investigation].
G-5
-------
GLOSSARY
Filtration: A treatment process for remov-
ing solid (particulate) matter from water by
passing the water through sand, activated
carbon, or a man-made filter. The process is
often used to remove particles that contain
contaminants.
Flood Plain: An area along a river, formed
from sediment deposited by floods. Flood
plains periodically are innundated by natural
floods, which can spread contamination.
Flue Gas: The air that is emitted from a
chimney after combustion in the burner
occurs. The gas can include nitrogen oxides,
carbon oxides, water vapor, sulfur oxides,
particles, and many chemical pollutants.
Fly Ash: Non-combustible residue that results
from the combustion of flue gases. It can
include nitrogen oxides, carbon oxides, water
vapor, sulfur oxides, as well as many other
chemical pollutants.
French Drain System: A crushed rock drain
system constructed of perforated pipes, which is
used to drain and disperse wastewater.
Gasification (coal): The conversion of soft
coal into gas for use as a fuel.
General Notice Letter: [See Notice Letter].
Generator: A facility that emits pollutants
into the air or releases hazardous wastes into
water or soil.
Good Faith Offer: A voluntary offer, gener-
ally in response to a Special Notice letter, made
by a potentially responsible party, consisting of
a written proposal demonstrating a potentially
responsible party's qualifications and willing-
ness to perform a site study or cleanup.
Groundwater: Water that fills pores in soils
or openings in rocks to the point of saturation.
In aquifers, groundwater occurs in sufficient
quantities for use as drinking and irrigation
water and other purposes.
Groundwater Quality Assessment: The
process of analyzing the chemical characteris-
tics of groundwater to determine whether any
hazardous materials exist.
Halogens: Reactive non-metals, such as
chlorine and bromine. Halogens are very
good oxidizing agents and, therefore, have
many industrial uses. They are rarely found
by themselves; however, many chemicals
such as polychlorinated biphenyls (PCBs),
some volatile organic compounds (VOCs),
and dioxin are reactive because of the pres-
ence of halogens.
Hazard Ranking System (HRS): The
principal screening tool used by the EPA to
evaluate relative risks to public health and the
environment associated with abandoned or
uncontrolled hazardous waste sites. The HRS
calculates a score based on the potential of
hazardous substances spreading from the site
through the air, surface water, or groundwater
and on other factors such as nearby popula-
tion. The HRS score is the primary factor in
deciding if the site should be on the NPL.
Hazardous Waste: By-products of society
that can pose a substantial present or potential
hazard to human health and the environment
when improperly managed. Hazardous waste
possesses at least one of four characteristics
(ignitability, corrosivity, reactivity, or toxic-
ity), or appears on special EPA lists.
Heavy Metals: Metallic elements with high
atomic weights, such as arsenic, lead, mercury,
and cadmium. Heavy metals are very hazardous
even at low concentrations and tend to accumu-
late in the food chain.
Herbicide: A chemical pesticide designed to
control or destroy plants, weeds, or grasses.
G-6
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GLOSSARY
Hot Spot: An area or vicinity of a site contain-
ing exceptionally high levels of contamination.
Hydrocarbons: Chemical compounds that
consist entirely of hydrogen and carbon.
Hydrology: The properties, distribution, and
circulation of water.
Hydrogeology: The geology of groundwater,
with particular emphasis on the chemistry and
movement of water.
Impoundment: A body of water or sludge
confined by a dam, dike, floodgate, or other
barrier.
Incineration: A group of treatment technolo-
gies involving destruction of waste by controlled
burning at high temperatures, e.g., burning
sludge to reduce the remaining residues to a
non-burnable ash that can be disposed of safely
on land, in some waters, or in underground
locations.
Infiltration: The movement of water or
other liquid down through soil from precipita-
tion (rain or snow) or from application of
wastewater to the land surface.
Influent: Water, wastewater, or other liquid
flowing into a reservoir, basin, or treatment
plant.
Injection Well: A well into which waste
fluids are placed, under pressure, for purposes
of disposal.
Inorganic Chemicals: Chemical sub-
stances of mineral origin, not of basic carbon
structure.
Installation Restoration Program: The
specially funded program established in 1978
under which the Department of Defense has
been identifying and evaluating its hazardous
waste sites and controlling the migration of
hazardous contaminants from those sites.
Intake: The source from where a water supply
is drawn, such as from a river or water body.
Interagency Agreement: A written agree-
ment between the EPA and a Federal agency
that has the lead for site cleanup activities,
setting forth the roles and responsibilities of the
agencies for performing and overseeing the
activities. States often are parties to interagency
agreements.
Interim (Permit) Status: Conditions under
which hazardous waste treatment, storage,
and disposal facilities, that were operating
when regulations under the RCRA became
final in 1980, are temporarily allowed by the
EPA to continue to operate while awaiting
denial or issuance of a permanent permit. The
facility must comply with certain regulations
to maintain interim status.
Lagoon: A shallow pond or liquid waste
containment structure. Lagoons typically are
used for the storage of wastewaters, sludges,
liquid wastes, or spent nuclear fuel.
Landfarm: To apply waste to land or incor-
porate waste into the surface soil, such as
fertilizer or soil conditioner. This practice
commonly is used for disposal of composted
wastes and sludges.
Landfill: A disposal facility where waste is
placed in or on land. Sanitary landfills are
disposal sites for non-hazardous solid wastes.
The waste is spread in layers, compacted to the
smallest practical volume, and covered with soil
at the end of each operating day. Secure chemi-
cal landfills are disposal sites for hazardous
waste. They are designed to minimize the
chance of release of hazardous substances into
the environment [see Resource Conservation
and Recovery Act].
Leach, Leaching [v.t.]: The process by
which soluble chemical components are dis-
solved and carried through soil by water or
some other percolating liquid.
G-7
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GLOSSARY
Leachate [n]: The liquid that trickles through
or drains from waste, carrying soluble compo-
nents from the waste.
Leachate Collection System: A system
that gathers liquid that has leaked into a landfill
or other waste disposal area and pumps it to the
surface for treatment.
Liner: A relatively impermeable barrier
designed to prevent leachate (waste residue)
from leaking from a landfill. Liner materials
include plastic and dense clay.
Long-term Remedial Phase: Distinct,
often incremental, steps that are taken to solve
site pollution problems. Depending on the
complexity, site cleanup activities can be
separated into several of these phases.
Long-term Response Action: An action
which requires a continuous period of on-site
activity before cleanup goals are achieved.
These actions typically include the extraction
and treatment of groundwater and monitoring
actions.
Marsh: A type of wetland that does not
contain peat moss deposits and is dominated by
vegetation. Marshes may be either fresh or
saltwater and tidal or non-tidal [see Wetland].
Migration: The movement of oil, gas, con-
taminants, water, or other liquids through porous
and permeable soils or rock.
Mill Tailings: [See Mine Tailings].
Mine Tailings: A fine, sandy residue left from
mining operations. Tailings often contain high
concentrations of lead, uranium, and arsenic or
other heavy metals.
Mitigation: Actions taken to improve site
conditions by limiting, reducing, or controlling
toxicity and contamination sources.
Modeling: A technique using a mathematical
or physical representation of a system or theory
that tests the effects that changes on system
components have on the overall performance of
the system.
Monitoring Wells: Special wells drilled at
specific locations within, or surrounding, a
hazardous waste site where groundwater can be
sampled at selected depths and studied to obtain
such information as the direction in which
groundwater flows and the types and amounts of
contaminates present.
National Priorities List (NPL): The
EPA's list of the most serious uncontrolled or
abandoned hazardous waste sites identified
for possible long-term cleanup under Super-
fund. The EPA is required to update the NPL
at least once a year.
Natural Attenuation: [See Attenuation].
Neutrals: Organic compounds that have a
relatively neutral pH, complex structure and,
due to their organic bases, are easily absorbed
into the environment. Water is the most
commonly known neutral, however, naphtha-
lene, pyrene, and trichlorobenzene also are
examples of neutrals.
Nitroaromatics: Common components of
explosive materials, which will explode if
activated by very high temperatures or pres-
sures; 2,4,6-Trinitrotoluene (TNT) is a
nitroaromatic.
Notice Letter: A General Notice Letter
notifies the parties potentially responsible for
site contamination of their possible liability. A
Special Notice Letter begins a 60-day formal
period of negotiation during which the EPA is
not allowed to start work at a site or initiate
enforcement actions against potentially respon-
sible parties, although the EPA may undertake
certain investigatory and planning activities.
G-8
-------
GLOSSARY
The 60-day period may be extended if the EPA
receives a good faith offer from the PRPs
within that period. [See also Good Faith Offer].
On-Scene Coordinator (OSC): The
predesignated EPA, Coast Guard, or Depart-
ment of Defense official who coordinates and
directs Superfund removal actions or Clean
Water Act oil- or hazardous-spill corrective
actions.
Operation and Maintenance: Activities
conducted at a site after a cleanup action is
completed to ensure that the cleanup or
containment system is functioning properly.
Organic Chemicals/Compounds:
Chemical substances containing mainly
carbon, hydrogen, and oxygen.
Outfall: The place where wastewater is
discharged into receiving waters.
Overpacking: Process used for isolating
large volumes of waste by jacketing or encap-
sulating waste to prevent further spread or
leakage of contaminating materials. Leaking
drums may be contained within oversized
barrels as an interim measure prior to removal
and final disposal.
Pentachlorophenol (PCP): A synthetic,
modified petrochemical that may be used as a
wood preservative because of its toxicity to
termites and fungi. It is a common component
of creosotes and can cause cancer.
Perched (groundwater): Groundwater
separated from another underlying body of
groundwater by a confining layer, often clay or
rock.
Percolation: The downward flow or filtering
of water or other liquids through subsurface
rock or soil layers, usually continuing down-
ward to groundwater.
Pesticide: A substance or mixture of sub-
stances intended to prevent, destroy, or repel any
pest. If misused, pesticides can accumulate in
the foodchain and contaminate the environment
Petrochemicals: Chemical substances
produced from petroleum in refinery operations
and as fuel oil residues. These include
fluoranthene, chrysene, mineral spirits, and
refined oils. Petrocheinicals are the bases from
which volatile organic compounds (VOCs),
plastics, and many pesticides are made. These
chemical substances often are toxic to humans
and the environment.
Phenols: Organic compounds that are used in
plastics manufacturing and are by-products of
petroleum refining, tanning, textile, dye, and
resin manufacturing. Phenols are highly poison-
ous.
Physical Chemical Separation: The
treatment process of adding a chemical to a
substance to separate the compounds for further
treatment or disposal.
Pilot Testing: A small-scale test of a pro-
posed treatment system in the field to determine
its ability to clean up specific contaminants.
Plugging: The process of stopping the flow of
water, oil, or gas into or out of die ground
through a borehole or well penetrating the
ground.
Plume: A body of contaminated groundwater
flowing from a specific source. The movement
of the groundwater is influenced by such factors
as local groundwater flow patterns, the character
of the aquifer in which groundwater is con-
tained, and the density of contaminants [see
Migration].
Pollution: Generally, the presence of matter
or energy whose nature, location, or quantity
produces undesired health or environmental
effects.
G-9
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GLOSSARY
Poly cyclic Aromatic Hydrocarbons or
Polyaromatic Hydrocarbons (PAHs):
PAHs, such as pyrene, are a group of highly
reactive organic compounds found in motor oil.
They are a common component of creosotes and
can cause cancer.
Polychlorinated Biphenyls (PCBs): A
group of toxic chemicals used for a variety of
purposes including electrical applications,
carbonless copy paper, adhesives, hydraulic
fluids, microscope immersion oils, and caulking
compounds. PCBs also are produced in certain
combustion processes. PCBs are extremely
persistent in the environment because they are
very stable, non-reactive, and highly heat
resistant. Chronic exposure to PCBs is believed
to cause liver damage. It also is known to
bioaccumulate in fatty tissues. PCB use and
sale was banned in 1979 with the passage of the
Toxic Substances Control Act
Polynuclear Aromatic Hydrocarbons
(PNAs): PNAs, such as naphthalene, and
biphenyls, are a group of highly reactive organic
compounds that are a common component of
creosotes, which can be carcinogenic.
Polyvinyl Chloride (PVC): A plastic made
from the gaseous substance vinyl chloride. PVC
is used to make pipes, records, raincoats, and
floor tiles. Health risks from high concentra-
tions of vinyl chloride include liver cancer and
lung cancer, as well as cancer of the lymphatic
and nervous systems.
Potable Water: Water that is safe for drink-
ing and cooking.
Potentially Responsible Parties (PRPs):
Parties associated with a Superfund site who
may be liable for the cost of remedying the
release of hazardous substances. This may
include owners or operators of the site or trans-
porters who disposed of materials at the site.
PRPs may admit liability, or liability may be
determined by a court of law. PRPs may sign a
Consent Decree or Administrative Order on
Consent to participate in the site cleanup without
admitting liability.
Precipitation: The removal of solids from
liquid waste so that the solid and liquid portions
can be disposed of safely; the removal of
particles from airborne emissions. Electro-
chemical precipitation is the use of an anode or
cathode to remove the hazardous chemicals.
Chemical precipitation involves the addition of
some substance to cause the solid portion to
separate.
Preliminary Assessment: The process of
collecting and reviewing available information
about a known or suspected waste site or release
to determine if a threat or potential threat exists.
Pump and Treat: A groundwater cleanup
technique involving the extracting of contami-
nated groundwater from the subsurface and the
removal of contaminants, using one of several
treatment technologies.
Radionuclides: Elements, including radium
and uranium-235 and -238, which break down
and produce radioactive substances due to their
unstable atomic structure. Some are man-made,
and others are naturally occurring in the envi-
ronment. Radon, the gaseous form of radium,
decays to form alpha particle radiation, which
cannot be absorbed through skin. However, it
can be inhaled, which allows alpha particles to
affect unprotected tissues directly and thus cause
cancer. Radiation also occurs naturally through
the breakdown of granite.
RCRA: [See Resource Conservation and
Recovery Act].
Recharge Area: A land area where rainwater
saturates the ground and soaks through the earth
to reach an aquifer.
G-10
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GLOSSARY
Record of Decision (ROD): A public
document that explains which cleanup
alternative(s) will be used to clean up sites
listed on the NPL. It is based on information
generated during the remedial investigation
and feasibility study and consideration of
public comments and community concerns.
Recovery Wells: Wells used to withdraw
contaminants or contaminated groundwater.
Recycle: The process of minimizing waste
generation by recovering usable products that
might otherwise become waste.
Remedial Action (RA): The actual con-
struction or implementation phase of a
Superfund site cleanup following the remedial
design [see Cleanup].
Remedial Design: A phase of site cleanup
where engineers design the technical specifi-
cations for cleanup remedies and technolo-
gies.
Remedial Investigation: An in-depth
study designed to gather the data necessary to
determine the nature and extent of contamina-
tion at a Superfund site, establish the criteria
for cleaning up the site, identify the prelimi-
nary alternatives for cleanup actions, and
support the technical and cost analyses of the
alternatives. The remedial investigation is
usually done with the feasibility study. In this
volume, the remedial investigation is referred
to as a site study [see also Feasibility Study].
Remedial Project Manager (RPM): The
EPA or State official responsible for oversee-
ing cleanup actions at the site.
Remedy Selection: The selection of the
final cleanup strategy for the site. At the few
sites where the EPA has determined that
initial response actions have eliminated site
contamination, or that any remaining con-
tamination will be naturally dispersed without
further cleanup activities, a "No Action"
remedy is selected [see Record of Decision].
Removal Action: Short-term immediate
actions taken to address releases of hazardous
substances [see Cleanup].
Residual: The amount of a pollutant re-
maining in the environment after a natural or
technological process has taken place, e.g.,
the sludge remaining after initial wastewater
treatment, or the particulates remaining in air
after the air passes through a scrubber.
Resource Conservation and Recovery
Act (RCRA): A Federal law that established
a regulatory system to track hazardous sub-
stances from the time of generation to dis-
posal. The law requires safe and secure
procedures to be used in treating, transport-
ing, storing, and disposing of hazardous
substances. RCRA is designed to prevent
new, uncontrolled hazardous waste sites.
Retention Pond: A small body of liquid
used for disposing of wastes and containing
overflow from production facilities. Some-
times retention ponds are used to expand the
capacity of such structures as lagoons the
store waste.
Runoff: The discharge of water over land
into surface water. It can carry pollutants
from the air and land and spread contaminants
from its source.
Scrubber: An air pollution control device
that uses a spray of water or reactant or a dry
process to trap pollutants in emissions.
Sediment: The layer of soil, sand, and
minerals at the bottom of surface waters such
as streams, lakes, and rivers, that absorbs
contaminants.
G-11
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GLOSSARY
Seeps: Specific points where releases of
liquid, usually leachate, form from waste
disposal areas, particularly along the lower
edges of landfills.
Seepage PitsT A hole, shaft, or cavity in
the ground used for the storage of liquids,
usually in the form of leachate, from waste
disposal areas. The liquid gradually leaves
the pit by moving through the surrounding
soil.
Septage: Residue remaining in a septic tank
after the treatment process.
Sinkhole: A hollow depression in the land
surface in which drainage collects; associated
with underground caves and passages that
facilitate the movement of liquids.
Site Characterization: The technical pro-
cess used to evaluate the nature and extent of
environmental contamination, which is neces-
sary for choosing and designing cleanup mea-
sures and monitoring their effectiveness.
Site Inspection: The collection of informa-
tion from a hazardous waste site to determine
the extent and severity of hazards posed by the
site. It follows, and is more extensive than, a
preliminary assessment. The purpose is to
gather information necessary to score the site,
using the Hazard Ranking System, and to
determine if the site presents an immediate
threat that requires a prompt removal action.
Slag: The fused refuse or dross separated
from a metal in the process of smelting.
Sludge: Semi-solid residues from industrial
or water treatment processes that may be
contaminated with hazardous materials.
Slurry Wall: Barriers used to contain the flow
of contaminated groundwater or subsurface
liquids. Slurry walls are constructed by digging
a trench around a contaminated area and filling
the trench with an impermeable material that
prevents water from passing through it. The
groundwater or contaminated liquids trapped
within the area surrounded by the slurry wall
can be extracted and treated.
Smelter: A facility that melts or fuses ore,
often with an accompanying chemical change,
to separate the metal. Emissions from smelters
are known to cause pollution.
Soil Gas: Gaseous elements and compounds
that occur in the small spaces between par-
ticles of soil. Such gases can move through
or leave the soil or rock, depending on
changes in pressure.
Soil Vapor Extraction: A treatment
process that uses vacuum wells to remove
hazardous gases from soil.
Soil Washing: A water-based process for
mechanically scrubbing soils in-place to remove
undesirable materials. There are two ap-
proaches: dissolving or suspending them in the
wash solution for later treatment by conven-
tional methods, and concentrating them into a
smaller volume of soil through simple particle
size separation techniques [see Solvent Extrac-
tion].
Stabilization: The process of changing an
active substance into inert, harmless material,
or physical activities at a site that act to limit
the further spread of contamination without
actual reduction of toxicity.
Solidification/Stabilization: A chemical
or physical reduction of the mobility of
hazardous constituents. Mobility is reduced
through the binding of hazardous constituents
into a solid mass with low permeability and
resistance to leaching.
G-12
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GLOSSARY
Solvent: A substance capable of dissolving
another substance to form a solution. The
primary uses of industrial solvents are as
cleaners for degreasing, in paints, and in
Pharmaceuticals. Many solvents are flam-
mable and toxic to varying degrees.
Solvent Extraction: A means of separating
hazardous contaminants from soils, sludges,
and sediment, thereby reducing the volume of
the hazardous waste that must be treated. It
generally is used as one in a series of unit
operations. An organic chemical is used to
dissolve contaminants as opposed to water-
based compounds, which usually are used in
soil washing.
Sorption: The action of soaking up or
attracting substances. It is used in many
pollution control systems.
Special Notice Letter: [See Notice Let-
ter].
Stillbottom: Residues left over from the
process of recovering spent solvents.
Stripping: A process used to remove volatile
contaminants from a substance [see Air Strip-
ping].
Sumps: A pit or tank that catches liquid
runoff for drainage or disposal.
Superf und: The program operated under the
legislative authority of the CERCLA and
Superfund Amendments and Reauthorization
Act (SARA) to update and improve environ-
mental laws. The program has the authority to
respond directly to releases or threatened re-
leases of hazardous substances that may endan-
ger public health, welfare, or the environment
The "Superfund" is a trust fund that finances
cleanup actions at hazardous waste sites.
Surge Tanks: A holding structure used to
absorb irregularities in flow of liquids, including
liquid waste materials.
Swamp: A type of wetland that is dominated
by woody vegetation and does not accumulate
peat moss deposits. Swamps may be fresh or
saltwater and tidal or non-tidal [see Wetlands].
Thermal Treatment: The use of heat to
remove or destroy contaminants from soil.
Treatability Studies: Testing a treatment
method on contaminated groundwater, soil, etc.,
to determine whether and how well the method
will work.
Trichloroethylene (TCE): A stable, color-
less liquid with a low boiling point. TCE has
many industrial applications, including use as
a solvent and as a metal degreasing agent.
TCE may be toxic to people when inhaled,
ingested, or through skin contact and can
damage vital organs, especially the liver [see
Volatile Organic Compounds].
Unilateral [Administrative] Order: [see
Administrative Order].
Upgradient: An upward hydrologic slope;
demarks areas that are higher than contaminated
areas and, therefore, are not prone to contamina-
tion by the movement of polluted groundwater.
Vacuum Extraction: A technology used to
remove volatile organic compounds (VOCs)
from soils. Vacuum pumps are connected to a
series of wells drilled to just above the water
table. The wells are sealed tightly at the soil
surface, and the vacuum established in the soil
draws VOC-contaminated air from the soil
pores into the well, as fresh air is drawn down
from the surface of the soil.
G-13
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GLOSSARY
Vegetated Soil Cap: A cap constructed with
graded soils and seed for vegetative growth, to
prevent erosion [see Cap].
Vitrification: The process of electrically
melting wastes and soils or sludges to bind the
waste in a glassy, solid material more durable
than granite or marble and resistant to leaching.
Volatile Organic Compounds (VOCs):
VOCs are manufactured as secondary petro-
chemicals. They include light alcohols, acetone,
trichloroethylene, perchloroethylene,
dichloroethylene, benzene, vinyl chloride,
toluene, and methylene chloride. These poten-
tially toxic chemicals are used as solvents,
degreasers, paints, thinners, and fuels. Because
of their volatile nature, they readily evaporate
into the air, increasing the potential exposure to
humans. Due to their low water solubility,
environmental persistence, and widespread
industrial use, they are commonly found in soil
and groundwater.
Waste Treatment Plant: A facility that
uses a series of tanks, screens, filters, and
other treatment processes to remove pollut-
ants from water.
Wastewater: The spent or used water from
individual homes or industries.
Watershed: The land area that drains into a
stream or other water body.
Water Table: The upper surface of the
groundwater.
Weir: A barrier to divert water or other liquids.
Wetland: An area that is regularly saturated
by surface or groundwater and, under normal
circumstances, is capable of supporting
vegetation typically adapted for life in satu-
rated soil conditions. Wetlands are critical to
sustaining many species of fish and wildlife.
Wetlands generally include swamps, marshes,
and bogs. Wetlands may be either coastal or
inland. Coastal wetlands have salt or brackish
(a mixture of salt and fresh) water, and most
have tides, while inland wetlands are non-
tidal and freshwater. Coastal wetlands are an
integral component of estuaries.
Wildlife Refuge: An area designated for
the protection of wild animals, within which
hunting and fishing are either prohibited or
strictly controlled.
G-u
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GLOSSARY
Some Common Contaminants at NPL Sites
Contaminant
Category
Example
Chemical Types
Sources
Potential Health
Threats*
Metals
Volatile Organic
Compounds
Creosotes
Radiation
Arsenic, Barium, Beryllium,
Cadmium, Cobalt, Copper,
Chromium, Lead, Manga-
nese, Mercury, Nickel,
Silver, Selenium, Zinc
Trichloroethylene (TCE),
Perchloroethylene (PCE),
Acetone, Benzene,
Ketone, Methyl chloride,
Toluene, Vinyl Chloride,
Dichlorethylene
Chlordane, DDT 4-4, DDE,
Heptachlor, Aldrin, Endrin,
Atrazine, Dieldrin, Toxa-
phene
Polyaromatic hydrocar-
bons (PAHs), Polynuclear
aromatics (PNAs),
Phenolic Tars, Pentachlo-
rophenol (PCP)
Radium-226, Radon,
Uranium-235, Uranium-
238
Electroplating, batteries,
paint pigments, photogra-
phy, smelting, thermom-
eters, fluorescent lights,
solvent recovery
Solvents and degreasers,
gasoline octane enhanc-
ers, oils and paints, dry
cleaning fluids, chemical
manufacturing.
Agricultural applications,
pesticide and herbicide
production
Electric transformers and
capacitors, insulators and
coolants, adhesives,
caulking compounds,
carbonless copy paper,
hydraulic fluids.
Wood preserving, fossil
fuel combustion
Mine tailings, radium
products, natural decay of
granites
Tumors, cancers, and kidney,
brain, neurological, bone and
liver damage
Cancers, kidney and liver
damage, impairment of the
nervous system resulting in
sleepiness and headaches,
leukemia
Various effects ranging from
nausea to nervous disorders.
Dioxin is a common by-product
of the manufacture of pesti-
cides and is both highly toxic
and a suspected carcinogen.
Cancer and liver damage.
Cancers and skin ulcerations
with prolonged exposure
Cancer
Sources:
Toxic Chemicals—What They Are, How They Affect You (EPA, Region 5)
Glossary of Environmental Terms (EPA, 1988)
'The potential for risk due to these contaminants is linked to a number of factors; for example, the length and level of exposure
and environmental and health factors such as age.
G-15
*U.S. G.P.O.:1993-341-835:81036
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