&EPA
United States
Environmental Protection
Agency
Solid Waste And
Emergency Response
(OS-240)
EPA/540/8-91-022
September 1991
PB92-963237
National
Priorities
List Sites:
COLORADO
Printed on Recycled Paper
-------
Publication #9200.5-707A
September 1991
NATIONAL PRIORITIES LIST SITES:
Colorado
u.*.v**^v^*^
Region 5,Library (PL-12,; _(
77 West Jackson Bo'-!./-::;, i^» ^
Chicago, IL 60b04-o:;,,
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Office of Emergency & Remedial Response
Office of Program Management
Washington, DC 20460
-------
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) 487-4650
The National Overview volume, Superfund: Focusing on the Nation at Large (1991),
may be ordered as PB92-963253.
The complete set of the overview documents, plus the 49 state reports may be ordered
as PB92-963253.
-------
TABLE OF CONTENTS
Page
Introduction:
A Brief Overview 1
Super fund:
How Does the Program Work to Clean Up Sites? 5
The Volume:
How to Use the State Book 13
NPL Sites:
In the State of Colorado 17
The NPL Report:
Progress to Date 19
The NPL Fact Sheets:
Summary of Site Activities 21
Appendix A: Glossary:
Terms Used in the Fact Sheets 67
Appendix B: Repositories of
Site Information 83
-------
INTRODUCTION
WHYTHESUPERFUND
PROGRAM?
As the 1970s came to a close, a series of
headline stories gave Americans a
look at the dangers of dumping indus-
trial and urban wastes on the land. First there
was New York's Love Canal. Hazardous
waste buried there over a 25-year period
contaminated streams and soil, and endangered
the health of nearby residents. The result:
evacuation of several hundred people. Then
the leaking barrels at the Valley of the Drums
in Kentucky attracted public attention, as did
the dioxin-tainted land and water in Times
Beach, Missouri.
In all these cases, human health and the envi-
ronment were threatened, lives were disrupted,
and property values were reduced. It became
increasingly clear that there were large num-
bers of serious hazardous waste problems that
were falling through the cracks of existing
environmental laws. The magnitude of these
emerging problems moved Congress to enact
the Comprehensive Environmental Response,
Compensation, and Liability Act in 1980.
CERCLA commonly known as Superfund
was the first Federal law established to deal
with the dangers posed by the Nation's hazard-
ous waste sites.
After Discovery, the Problem
Intensified
Few realized the size of the problem until the
Environmental Protection Agency (EPA)
began the process of site discovery and site
evaluation. Not hundreds, but thousands of
potential hazardous waste sites existed, and
they presented the Nation with some of the
most complex pollution problems it had ever
faced.
Since the Superfund program began, hazard-
A
Brief
Overview
ous waste has surfaced as a major environ-
mental concern in every part of the United
States. It wasn't just the land that was con-
taminated by past disposal practices. Chemi-
cals in the soil were spreading into the ground-
water (a source of drinking water for many)
and into streams, lakes, bays, and wetlands.
Toxic vapors contaminated the air at some
sites, while improperly disposed or stored
wastes threatened the health of the surrounding
community and the environment at others.
The EPA Identified More than 1,200
Serious Sites
The EPA has identified 1,245 hazardous waste
sites as the most serious in the Nation. These
sites comprise the National Priorities List; sites
targeted for cleanup under Super-fund. But
site discoveries continue, and the EPA esti-
mates that, while some will be deleted after
lengthy cleanups, this list, commonly called
the NPL, will continue to grow by approxi-
mately 50 to 100 sites per year, potentially
reaching 2,100 sites by the year 2000.
THE NATIONAL CLEANUP
EFFORT IS MUCH MORE THAN
THE NPL
From the beginning of the program, Congress
recognized that the Federal government could
-------
INTRODUCTION
not and should not address all environmental
problems stemming from past disposal prac-
tices. Therefore, the EPA was directed to set
priorities and establish a list of sites to target.
Sites on the NPL (1,245) thus are a relatively
small subset of a larger inventory of potential
hazardous waste sites, but they do comprise
the most complex and compelling cases. The
EPA has logged more than 35,000 sites on its
national inventory of potentially hazardous
waste sites and assesses each site within one
year of being logged.
THE EPA IS MAKING PROGRESS
ON SITE CLEANUP
The goal of the Superfund program is to tackle
immediate dangers first and then move through
the progressive steps necessary to eliminate
any long-term risks to public health and the
environment.
Superfund responds immediately to sites
posing imminent threats to human health and
the environment at both NPL sites and sites not
on the NPL. The purpose is to stabilize,
prevent, or temper the effects of a release of
hazardous substances, or the threat of one, into
the environment. These might include tire
fires or transportation accidents involving the
spill of hazardous chemicals. Because they
reduce the threat a site poses to human health
and the environment, immediate cleanup
actions are an integral part of the Superfund
program.
Immediate response to imminent threats is one
of Superfund's most noted achievements.
Where imminent threats to the public or
environment were evident, the EPA has initi-
ated or completed emergency actions that
attacked the most serious threats of toxic
exposure in more than 2,700 cases.
The ultimate goal for a hazardous waste site on
the NPL is a permanent solution to an environ-
mental problem that presents a serious threat
to the public or the environment. This often
requires a long-term effort. The EPA has
aggressively accelerated its efforts to perform
these long-term cleanups of NPL sites. More
cleanups were started in 1987, when the
Superfund law was amended, than in any
previous year. By 1991, construction had
started at more than four times as many sites as
in 1986! Of the sites currently on the NPL,
more than 500 nearly half have had
construction cleanup activity. In addition,
more than 400 more sites presently are in the
investigation stage to determine the extent of
site contamination and to identify appropriate
cleanup remedies. Many other sites with
cleanup remedies selected are poised for the
start of cleanup construction activity. In
measuring success by "progress through the
cleanup pipeline," the EPA clearly is gaining
momentum.
THE EPA MAKES SURE
CLEANUP WORKS
The EPA has gained enough experience in
cleanup construction to understand that envi-
ronmental protection does not end when the
remedy is in place. Many complex technolo-
gies like those designed to clean up ground-
water must operate for many years in order
to accomplish their objectives.
The EPA's hazardous waste site managers are
committed to proper operation and mainte-
nance of every remedy constructed. No matter
who has been delegated responsibility for
monitoring the cleanup work, the EPA will
assure that the remedy is carefully followed
and that it continues to do its job.
Likewise, the EPA does not abandon a site
even after the cleanup work is done. Every
five years, the Agency reviews each site where
residues from hazardous waste cleanup still
remain to ensure that public and environmental
-------
INTRODUCTION
health are being safeguarded. The EPA will
correct any deficiencies discovered and will
report to the public annually on all five-year
reviews conducted that year.
CITIZENS HELP SHAPE
DECISIONS
Superfund activities also depend upon local
citizen participation. The EPA's job is to
analyze the hazards and to deploy the experts,
but the Agency needs citizen input as it makes
choices for affected communities.
Because the people in a community where a
Superfund site is located will be those most
directly affected by hazardous waste problems
and cleanup processes, the EPA encourages
citizens to get involved in cleanup decisions.
Public involvement and comment does influ-
ence EPA cleanup plans by providing valuable
information about site conditions, community
concerns, and preferences.
The State and U.S. Territories volumes and the
companion National overview volume provide
general Superfund background information
and descriptions of activities at each NPL site.
These volumes clearly describe what the
problems are, what the EPA and others partici-
pating in site cleanups are doing, and how we,
as a Nation, can move ahead in solving these
serious problems.
USING THE STATE AND
NATIONAL VOLUMES TOGETHER
To understand the big picture on hazardous
waste cleanup, citizens need to hear about both
environmental progress across the country and
the cleanup accomplishments closer to home.
Citizens also should understand the challenges
involved in hazardous waste cleanup and the
decisions we must make, as a Nation, in
finding the best solutions.
The National overview, Superfund: Focusing
on the Nation at Large (1991), contains impor-
tant information to help you understand the
magnitude and challenges facing the
Superfund program, as well as an overview of
the National cleanup effort. The sections
describe the nature of the hazardous waste
problem nationwide, threats and contaminants
at NPL sites and their potential effects on
human health and the environment, vital roles
of the various participants in the cleanup
process, the Superfund program's successes in
cleaning up the Nation's serious hazardous
waste sites, and the current status of the NPL.
If you did not receive this overview volume,
ordering information is provided in the front of
this book.
This volume compiles site summary fact sheets
on each State or Territorial site being cleaned
up under the Superfund program. These sites
represent the most serious hazardous waste
problems in the Nation and require the most
complicated and costly site solutions yet
encountered. Each book gives a "snapshot" of
the conditions and cleanup progress that has
been made at each NPL site. Information
presented for each site is current as of April
1991. Conditions change as our cleanup
efforts continue, so these site summaries will
be updated annually to include information on
new progress being made.
To help you understand the cleanup accom-
plishments made at these sites, this volume
includes a description of the process for site
discovery, threat evaluation, and long-term
cleanup of Superfund sites. This description,
How Does the Program Work to Clean Up
Sites?, will serve as a reference point from
which to review the cleanup status at specific
sites. A glossary defining key terms as they
apply to hazardous waste management and site
cleanup is included as Appendix A in the back
of this book.
-------
SUPERFUND
The diverse problems posed by hazard-
ous waste sites have provided the EPA
with the challenge to establish a consis-
tent approach for evaluating and cleaning up
the Nation's most serious sites. To do this, the
EPA has had to step beyond its traditional role
as a regulatory agency to develop processes
and guidelines for each step in these techni-
cally complex site cleanups. The EPA has
established procedures to coordinate the
efforts of its Washington, D.C. Headquarters
program offices and its front-line staff in ten
Regional Offices, with the State and local
governments, contractors, and private parties
who are participating in site cleanup. An
important part of the process is that any time
How Does the
Program Work
to Clean Up
Sites?
THREE-STEP SUPERFUND PROCESS
STEP1
Discover site and
determine whether
an emergency
exists *
STEP 2
Evaluate whether a
site is a serious threat
to public health or
environment
STEP 3
Perform long-term
cleanup actions on
the most serious
hazardous waste
sites in the Nation
' Emergency actions are performed whenever needed in this three-step process.
during cleanup, work can be led by the EPA
or the State or, under their monitoring, by
private parties who are potentially responsible
for site contamination.
The process for discovery of the site, evalu-
ation of threat, and the long-term cleanup of
Superfund sites is summarized in the follow-
ing pages. The phases of each of these steps
are highlighted within the description. The
flow diagram above provides a summary of the
three-step process.
Although this book provides a current "snap-
shot" of site progress made only by emergency
actions and long-term cleanup actions at
Superfund sites, it is important to understand
the discovery and evaluation process that leads
to identifying and cleaning up these most
serious uncontrolled or abandoned hazardous
-------
SUPERFUND
waste sites in the Nation. The discovery and
evaluation process is the starting point for this
summary description of Superfund involve-
ment at hazardous waste sites.
STEP 1: SITE DISCOVERY AND
EMERGENCY EVALUATION
How does the EPA learn about
potential hazardous waste sites?
Site discovery occurs in a number of ways.
Information comes from concerned citizens.
People may notice an odd taste or foul odor in
their drinking water or see half-buried leaking
barrels; a hunter may come across a field
where waste was dumped illegally. There may
be an explosion or fire, which alerts the State
or local authorities to a problem. Routine
investigations by State and local governments
and required reporting and inspection of
facilities that generate, treat, store, or dispose
of hazardous waste also help keep the EPA
informed about actual or potential threats of
hazardous substance releases. All reported
sites or spills are recorded in the Superfund
inventory (CERCLIS) for further investigation
to determine whether they will require cleanup.
What happens if there is an imminent
danger?
As soon as a potential hazardous waste site is
reported, the EPA determines whether there is
an emergency requiring an immediate cleanup
action. If there is, they act as quickly as
possible to remove or stabilize the imminent
threat. These short-term emergency actions
range from building a fence around the con-
taminated area to keep people away, or tempo-
rarily relocating residents until the danger is
addressed, to providing bottled water to resi-
dents while their local drinking water supply is
being cleaned up or physically removing
wastes for safe disposal.
However, emergency actions can happen at
any time an imminent threat or emergency
warrants them. For example, if leaking barrels
are found when cleanup crews start digging in
the ground or if samples of contaminated soils
or air show that there may be a threat of fire or
explosion, an immediate action is taken.
STEP 2: SITE THREAT EVALUATION
If there isn't an imminent danger, how
does the EPA determine what, if any,
cleanup actions should be taken?
Even after any imminent dangers are taken
care of, in most cases, contamination may
remain at the site. For example, residents may
have been supplied with bottled water to take
care of their immediate problem of contami-
nated well water, but now it's time to deter-
mine what is contaminating the drinking water
supply and the best way to clean it up. The
EPA may determine that there is no imminent
danger from a site, so any long-term threats
need to be evaluated. In either case, a more
comprehensive investigation is needed to
determine if a site poses a serious, but not
imminent, danger and whether it requires a
long-term cleanup action.
Once a site is discovered and any needed
emergency actions are taken, the EPA or the
State collects all available background infor-
mation not only from their own files, but also
from local records and U.S. Geological Survey
maps. This information is used to identify the
site and to perform a preliminary assessment of
its potential hazards. This is a quick review of
readily available information to answer the
questions:
Are hazardous substances likely to be
present?
-------
SUPERFUND
How are they contained?
How might contaminants spread?
How close is the nearest well, home, or
natural resource area such as a wetland
or animal sanctuary?
What may be harmed the land,
water, air, people, plants, or animals?
Some sites do not require further action be-
cause the preliminary assessment shows that
they do not threaten public health or the envi-
ronment. But even in these cases, the sites
remain listed in the Superfund inventory for
record-keeping purposes and future reference.
Currently, there are more than 35,000 sites
maintained in this inventory.
If the preliminary assessment
shows a serious threat may exist,
what's the next step?
Inspectors go to the site to collect additional
information to evaluate its hazard potential.
During this site inspection, they look for
evidence of hazardous waste, such as leaking
drums and dead or discolored vegetation.
They may take some samples of soil, well
water, river water, and air. Inspectors analyze
the ways hazardous materials could be pollut-
ing the environment, such as runoff into
nearby streams. They also check to see if
people (especially children) have access to
the site.
How does the EPA use the results of
the site inspection?
Information collected during the site inspection
is used to identify the sites posing the most
serious threats to human health and the envi-
ronment. This way, the EPA can meet the
requirement that Congress gave them to use
Superfund monies only on the worst hazardous
waste sites in the Nation.
To identify the most serious sites, the EPA
developed the Hazard Ranking System (HRS).
The HRS is the scoring system the EPA uses to
assess the relative threat from a release or a
potential release of hazardous substances from
a site to surrounding groundwater, surface
water, air, and soil. A site score is based on
the likelihood that a hazardous substance will
be released from the site, the toxicity and
amount of hazardous substances at the site, and
the people and sensitive environments poten-
tially affected by contamination at the site.
Only sites with high enough health and envi-
ronmental risk scores are proposed to be added
to the NPL. That's why 1,245 sites are on the
NPL, but there are more than 35,000 sites in
the Superfund inventory. Only NPL sites can
have a long-term cleanup paid for from
Superfund, the national hazardous waste trust
fund. Superfund can, and does, pay for emer-
gency actions performed at any site, whether
or not it's on the NPL.
Why are sites proposed to the NPL?
Sites proposed to the NPL have been evaluated
through the scoring process as the most serious
problems among uncontrolled or abandoned
hazardous waste sites in the U.S. In addition, a
site will be proposed to the NPL if the Agency
for Toxic Substances and Disease Registry
issues a health advisory recommending that
people be moved away from the site. The NPL
is updated at least once a year, and it's only
after public comments are considered that
these proposed worst sites officially are added
to the list.
Listing on the NPL does not set the order in
which sites will be cleaned up. The order is
influenced by the relative priority of the site's
health and environmental threats compared to
other sites, and such factors as State priorities,
engineering capabilities, and available tech-
-------
SUPERFUND
nologies. Many States also have their own list
of sites that require cleanup; these often contain
sites that are not on the NPL and are scheduled
to be cleaned up with State money. And, it
should be noted again that any emergency
action needed at a site can be performed by the
Superfund, whether or not a site is on the NPL.
A detailed description of the current progress in
cleaning up NPL sites is found in the section of
the 1991 National overview volume entitled
Cleanup Successes: Measuring Progress.
How do people find out whether the
EPA considers a site a national
priority for cleanup under the
Superfund Program?
All NPL sites, where Superfund is responsible
for cleanup, are described in the State and
Territorial volumes. The public also can find
out whether other sites, not on the NPL, are
being addressed by the Superfund program by
calling their Regional EPA office or the Super-
fund Hotline at the numbers listed in this book.
STEP 3: LONG-TERM CLEANUP
ACTIONS
After a site is added to the NPL, what
are the steps to cleanup?
The ultimate goal for a hazardous waste site on
the NPL is a permanent, long-term cleanup.
Since every site presents a unique set of chal-
lenges, there is no single all-purpose solution.
A five-phase "remedial response" process is
used to develop consistent and workable
solutions to hazardous waste problems across
the Nation:
1. Remedial Investigation: investigate in
detail the extent of the site contamination
2. Feasibility Study: study the range of
possible cleanup remedies
3. Record of Decision or ROD: decide
which remedy to use
4. Remedial Design: plan the remedy
5. Remedial Action: carry out the remedy
This remedial response process is a long-term
effort to provide a permanent solution to an
environmental problem that presents a serious
threat to the public or environment.
The first two phases of a long-term cleanup are
a combined remedial investigation and feasibil-
ity study (RI/FS) that determine the nature and
extent of contamination at the site and identify
and evaluate cleanup alternatives. These
studies may be conducted by the EPA or the
State or, under their monitoring, by private
parties.
Like the initial site inspection described earlier,
a remedial investigation involves an examina-
tion of site data in order to better define the
problem. However, the remedial investigation
is much more detailed and comprehensive than
the initial site inspection.
A remedial investigation can best be described
as a carefully designed field study. It includes
extensive sampling and laboratory analyses to
generate more precise data on the types and
quantities of wastes present at the site, the type
of soil and water drainage patterns, and specific
human health and environmental risks.
The result of the remedial investigation is
information that allows the EPA to select the
cleanup strategy that is best suited to a particu-
lar site or to determine that no cleanup is
needed.
Placing a site on the NPL does not necessarily
mean that cleanup is needed. It is possible for
-------
SUPERFUND
a site to receive an HRS score high enough to
be added to the NPL, but not ultimately require
cleanup actions. Keep in mind that the purpose
of the scoring process is to provide a prelimi-
nary and conservative assessment of potential
risk. During subsequent site investigations, the
EPA may find either that there is no real threat
or that the site does not pose significant human
health or environmental risks.
How are cleanup alternatives
identified and evaluated?
The EPA or the State or, under their monitor-
ing, private parties identify and analyze spe-
cific site cleanup needs based on the extensive
information collected during the remedial
investigation. This analysis of cleanup alterna-
tives is called a feasibility study.
Since cleanup actions must be tailored exactly
to the needs of each individual site, more than
one possible cleanup alternative is always
considered. After making sure that all potential
cleanup remedies fully protect human health
and the environment and comply with Federal
and State laws, the advantages and disadvan-
tages of each cleanup alternative are compared
carefully. These comparisons are made to
determine their effectiveness in the short and
long term, their use of permanent treatment
solutions, and their technical feasibility and
cost.
To the maximum extent practicable, the rem-
edy must be a permanent solution and must use
treatment technologies to destroy principal site
contaminants. Remedies such as containing the
waste on site or removing the source of the
problem (like leaking barrels) often are consid-
ered effective. Often, special pilot studies are
conducted to determine the effectiveness and
feasibility of using a particular technology to
clean up a site. Therefore, the combined
remedial investigation and feasibility study can
take between 10 and 30 months to complete,
depending on the size and complexity of the
problem.
Does the public have a say in the
final cleanup decision?
Yes. The Superfund law requires that the
public be given the opportunity to comment on
the proposed cleanup plan. Their concerns are
considered carefully before a final decision is
made.
The results of the remedial investigation and
feasibility study, which also point out the
recommended cleanup choice, are published in
a report for public review and comment. The
EPA or the State encourages the public to
review the information and take an active role
in the final cleanup decision. Fact sheets and
announcements in local papers let the commu-
nity know where they can get copies of the
study and other reference documents concern-
ing the site. Local information repositories,
such as libraries or other public buildings, are
established in cities and towns near each NPL
site to ensure that the public has an opportunity
to review all relevant information and the
proposed cleanup plans. Locations of informa-
tion repositories for each NPL site described in
this volume are given in Appendix B.
The public has a minimum of 30 days to
comment on the proposed cleanup plan after it
is published. These comments can be written
or given verbally at public meetings that the
EPA or the State are required to hold. Neither
the EPA nor the State can select the final
cleanup remedy without evaluating and provid-
ing written answers to specific community
comments and concerns. This "responsiveness
summary" is part of the EPA's write-up of the
final remedy decision, called the Record of
Decision, or ROD.
The ROD is a public document that explains
the cleanup remedy chosen and the reason it
-------
SUPERFUND.
was selected. Since sites frequently are large
and must be cleaned up in stages, a ROD may
be necessary for each contaminated resource or
area of the site. This may be necessary when
contaminants have spread into the soil, water,
and air and affect such sensitive areas as
wetlands, or when the site is large and cleaned
up in stages. This often means that a number
of remedies, using different cleanup technolo-
gies, are needed to clean up a single site.
If every cleanup action needs to be
tailored to a site, does the design
ofthe remedy need to be tailored,
too?
Yes. Before a specific cleanup action is carried
out, it must be designed in detail to meet
specific site needs. This stage of the cleanup is
called the remedial design. The design phase
provides the details on how the selected rem-
edy will be engineered and constructed.
Projects to clean up a hazardous waste site may
appear to be like any other major construction
project but, in fact, the likely presence of
combinations of dangerous chemicals demands
special construction planning and procedures.
Therefore, the design of the remedy can take
anywhere from six months to two years to
complete. This blueprint for site cleanup
includes not only the details on every aspect of
the construction work, but a description of the
types of hazardous wastes expected at the site,
special plans for environmental protection,
worker safety, regulatory compliance, and
equipment decontamination.
Once the design is completed,
how long does it take to actually
clean up the site, and how much
does it cost?
The time and cost for performing the site
cleanup, called the remedial action, are as
varied as the remedies themselves. In a few
cases, the only action needed may be to remove
drums of hazardous waste and to decontami-
nate them, an action that takes limited time and
money. In most cases, however, a remedial
action may involve different and expensive
cleanup measures that can take a long time.
For example, cleaning polluted groundwater or
dredging contaminated river bottoms can take
several years of complex engineering work
before contamination is reduced to safe levels.
Sometimes the selected cleanup remedy de-
scribed in the ROD may need to be modified
because of new contaminant information
discovered or difficulties that were faced
during the early cleanup activities. Taking into
account these differences, each remedial
cleanup action takes an average of 18 months
to complete and ultimately costs an average of
$26 million to complete all necessary cleanup
actions at a site.
Once the cleanup action is
completed, is the site
automatically "deleted" from the
NPL?
No. The deletion of a site from the NPL is
anything but automatic. For example, cleanup
of contaminated groundwater may take up to
20 years or longer. Also, in some cases, long-
term monitoring of the remedy is required to
ensure that it is effective. After construction of
certain remedies, operation and maintenance
(e.g., maintenance of ground cover, groundwa-
ter monitoring, etc.), or continued pumping and
treating of groundwater may be required to
ensure that the remedy continues to prevent
future health hazards or environmental damage
and ultimately meets the cleanup goals speci-
fied in the ROD. Sites in this final monitoring
or operational stage of the cleanup process are
designated as "construction complete."
It's not until a site cleanup meets all the goals
and monitoring requirements of the selected
10
-------
SUPERFUND
remedy that the EPA can officially propose the
site for deletion from the NPL, and it's not
until public comments are taken into consid-
eration that a site actually can be deleted from
the NPL. All sites deleted from the NPL and
sites with completed construction are included
in the progress report found later in this book.
Can a site be taken off the NPL if
no cleanup has taken place?
Yes. But only if further site investigation
reveals that there are no threats present at the
site and that cleanup activities are not neces-
sary. In these cases, the EPA will select a "no
action" remedy and may move to delete the
site when monitoring confirms that the site
does not pose a threat to human health or the
environment.
In other cases, sites may be "removed" from
the NPL if new information concerning site
cleanup or threats show that the site does not
warrant Superfund activities.
A site may be removed if a revised HRS
scoring, based on updated information, results
in a score below the minimum for NPL sites.
A site also may be removed from the NPL by
transferring it to other appropriate Federal
cleanup authorities, such as RCRA, for further
cleanup actions.
Removing sites for technical reasons or trans-
ferring sites to other cleanup programs pre-
serves Superfund monies for the Nation's most
pressing hazardous waste problems where no
other cleanup authority is applicable.
Can the EPA make parties
responsible for the contamination
pay?
Yes. Based on the belief that "the polluters
should pay," after a site is placed on the NPL,
the EPA makes a thorough effort to identify
and find those responsible for causing con-
tamination problems at a site. Although the
EPA is willing to negotiate with these private
parties and encourages voluntary cleanup, it
has the authority under the Superfund law to
legally force those potentially responsible for
site hazards to take specific cleanup actions.
All work performed by these parties is closely
guided and monitored by the EPA and must
meet the same standards required for actions
financed through the Superfund.
Because these enforcement actions can be
lengthy, the EPA may decide to use Superfund
monies to make sure a site is cleaned up
without unnecessary delay. For example, if a
site presents an imminent threat to public
health and the environment or if conditions at a
site may worsen, it could be necessary to start
the cleanup right away. Those responsible for
causing site contamination are liable under the
law (CERCLA) for repaying the money the
EPA spends in cleaning up the site.
Whenever possible, the EPA and the Depart-
ment of Justice use their legal enforcement
authorities to require responsible parties to pay
for site cleanups, thereby preserving Superfund
resources for emergency actions and for sites
where no responsible parties can be identified.
11
-------
THE VOLUME
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 discov-
ered and related threats to public and ecologi-
cal health ("Threats and Contaminants").
"Cleanup Approach" presents 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 environ-
ment. The summaries also pinpoint other
actions, such as legal efforts to involve pollut-
ers responsible for site contamination and
community concerns.
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-
How to Use
the State
Book
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.
13
-------
THE VOLUME
NPL LISTING HISTORY
Dates when the site was
Proposed, made Final, and
Deleted from the NPL.
SITE RESPONSIBILITY
Identifies the Federal, State,
and/or potentially respon-
sible parties that are taking
responsibility for cleanup
actions at the site.
SITE NAME
STATE
EPA ID* ABCOOOOOOO
EPA REGION XX
CONGRESSIONAL DIST XX
COUNTY NAME
hreats and Contaminants
Cleanup Approach
Response Action Status
Site Facts:,
Environmental Progress
ENVIRONMENTAL PROGRESS
A summary of the actions to reduce the threats to
nearby residents and the surrounding environment;
progress towards cleaning up the site and goals of
the cleanup plan are given here.
©
14
-------
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.
15
-------
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 Contaminated Groundwater in
the vicinity or underlying the site.
(Groundwater is often used as a
drinking water source.)
Contaminated Surface Water and
Sediments on or near the site. (These
include lakes, ponds, streams, and
rivers.)
Contaminated Air in the vicinity of
the site. (Air pollution usually is
periodic and involves contaminated
dust particles or hazardous gas 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 vicin-
ity of the site. (Examples include
wetlands and coastal areas or critical
habitats.)
Icons in the Response Action
Status Section
Initial 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.
Environmental Progress summa-
rizes the activities taken to date to
protect human health and to clean
up site contamination.
16
-------
NPL SITES
The State of
Colorado
The State of Colorado is located in the west central United States within EPA Region 8. Region
8 includes six north central states extending from the mid-western plains to the Rocky Moun-
tains. Colorado covers 104,091 square miles consisting of high plains terrain in the east, a hilly
to mountainous plateau in the central section, and the Rocky Mountains with high ranges, broad
valleys, and deep canyons in the west. Currently ranked 36th in U.S. populations, according to
the 1990 Census, Colorado experienced a 14 percent increase in population since 1980 and has
approximately 3,294,000 residents. Tourism, agriculture, and aerospace comprise the principal
state industries. Colorado manufacturing produces electronics equipment, foods, and machinery.
How Many NPL Sites
Are in the State of Colorado?
Proposed
Final
Deleted
0
16
_Q
16
Where Are the NPL Sites Located?
Congressional District 1
Congressional District 2, 3,4
Congressional District 5, 6
2 sites
4 sites
1 site
What Type of Sites are on the NPL
in the State of Colorado?
# of sites
4
3
2
2
1
1
3
type of sites
Mining
Federal Facilities
Municipal & Industrial Landfills
Chemicals & Allied Products
Recyler
Lumber & Wood Products
Other Manufacturing (radium, uranium
mill, various manufacturers)
17
April 1991
-------
NPL SITES
How Are Sites Contaminated and What Are the Principal* Chemicals?
15--
12--
1,4
M
3 --
GW Soil SW Air
Contamination Area
Sed
Groundwater: Volatile organic
compounds (VOCs), heavy metals
(inorganics), and radiation.
Soil: Heavy metals (inorganics),
creosotes (organics), pesticides, and
radiation.
Air: Radiation.
Surface Water and Sediments:
Heavy metals (inorganics), creosotes
(organics), volatile organic com-
pounds (VOCs), pesticides, and
radiation.
Appear at 20% or more sites
Where Are the Sites in the Superfund Cleanup Process?1
3
Sites
with Bj
Studies
Underway
Sites
* with
Remedy
Selected
3
Sites
^ with
Remedy
Design
10
Sites
^ with
Cleanup
Ongoing
N
Sites
^ with
Construction
Complete
Deleted
Sites
In addition to activities described above, initial actions have been taken at 13 sites as intermediate
cleanup measures.
'Cleanup status reflects phases of site activities rather than administrative accomplishments.
April! 991
18
-------
THE NPL REPORT
The following Progress Report lists all
sites currently on, or deleted from, the
NPL and briefly summarizes the status
of activities for each site at the time this
report was prepared. The steps in the Super-
fund cleanup process are arrayed across the
top of the chart, and each site's progress
through these steps is represented by an arrow
indicating the current stage of cleanup.
Progress
To Date
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
accomplishments.
An arrow in the "Initial Response" cate-
gory indicates that an emergency cleanup or
initial action has been completed or currently
is underway. Emergency or initial actions are
taken as an interim measure to provide im-
mediate relief from exposure to hazardous site
conditions or to stabilize a site to prevent
further contamination.
A final arrow in the "Site Studies"
category indicates that an investigation to
determine the nature and extent of the
contamination at the site currently is ongoing.
A final arrow in the "Remedy Selection"
category means that the EPA has selected 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" remedy is 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 specifications for the
selected cleanup remedies and technologies.
A final arrow in the "Cleanup Ongoing"
column means that final cleanup actions have
been started at the site and currently are
underway.
A final arrow in the "Construction
Complete" category is used only when all
phases of the site cleanup plan have been
performed, and the EPA has determined 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 protect human
health and the environment.
A check in the "Deleted" category indicates
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.
19
April 1991
-------
ftftft ftftft ftftft
o
o
(0
_o
o
a
0)
C^S
^^«
0)
+-
c
0>
55
0.
Z
+-
(0
a
c
(0
O
o
I
(A
£
O)
O
ftftftft
ftftftftft
ft ft ft ft ft ft
ftftftftftft ft
.S
.5 .1 .5 .3 .G 1 .S .S .1 1 .1 .1
1
§
q
tu
CO
O
a <
April 1991
20
-------
THE NPL FACT SHEETS
Summary
of Site
Activities
EPA REGION 8
21
April 1991
-------
Who Do I Call with Questions?
The following pages describe each NPL site in Colorado, providing specific
information on threats and contaminants, cleanup activities, and environmental
progress. Should you have questions, please call EPA's Region 8 Office in
Denver, Colorado or one of the other offices listed below:
EPA Region 8 Superfund Community Relations Office
EPA Region 8 Superfund Office
EPA Superfund Hotline
EPA Headquarters Public Information Center
Colorado Superfund Office
(303)294-1100
(303) 293-1720
(800) 424-9346
(202) 260-2080
(303) 331-4465
April 1991
22
-------
AIR FORCE PLANT
PROJECTS
COLORADO
EPA ID# CO7570090038
EPA REGION 8
CONGRESSIONAL DIST. 06
Jefferson County
Waterton
O
Site Description
The 464-acre Air Force Plant PJKS Projects 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 is a major recreational area used by
local residents and visitors.
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
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. People who have direct contact with or accidentally ingest
contaminated surface water, groundwater, or surface wastes may suffer adverse health
effects.
23
April 1991
-------
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 Projects 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 exposure to hazardous
materials at the Air Force Plant PJKS Projects site while further investigations and cleanup activities
are taking place.
April 1991 24 AIR FORCE PLANT PJKS PROJECTS
-------
BRODERICK WO
PRODUCTS
COLORADO
EPA ID#COD000110254
EPA REGION 8
CONGRESSIONAL DIST. 02
Adams County
Denver
Site Description
The 64-acre Broderick Wood Products site is a former wood treatment plant with three main
activities that have contributed to contamination: wood treatment operations between 1947 and
1981; railroad shops on site before 1947; and smelting operations on adjacent property. 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 are called
the "main" and "secondary" impoundments, and are the main sources of contamination on the site.
The main impoundment contains a surface layer of oil and grease, a water layer, and a sludge layer.
The secondary impoundment holds mainly sludge. The combined contents probably totalled 4,000
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 appear 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 a snow fence around them, 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 LISTING HISTORY
Proposed Date: 09/08/83
Final Date: 09/21/84
Threats and Contaminants
Groundwater, surface water, impoundment sludges, and soil are contaminated with
various polycyclic aromatic hydrocarbons (PAHs), PCP, and volatile organic compounds
(VOCs). In addition, soil and surface water are contaminated with various heavy metals.
People may incur health risks by coming into direct contact with or accidentally ingesting
contaminated groundwater, surface water, or soil.
25
April 1991
-------
Cleanup Approach
This site is being addressed in two long-term remedial phases focusing on cleanup of the surface
impoundment sludges and soil, surface water, and groundwater cleanup.
Response Action Status
Surface Impoundment Sludges: In a recent decision, the EPA has modified the
selected remedy for this phase of the site cleanup to address the sludges found in the site
impoundments. All other planned cleanup activities will be investigated and addressed in
the next phase of site cleanup. In 1989, the potentially responsible parties installed a security fence
at the site. The EPA currently is excavating the contaminated sludges and oils and is treating the
material by incineration. Remaining ash from the incinerator process will be disposed of off site.
Cleanup actions for this phase are expected to be completed in 1991.
Soils, Surface Water, and Groundwater: In 1990, the potentially responsible parties
began an investigation, under EPA monitoring, that will further explore the nature and
extent of pollution at and around the property. The investigation is specifically targeting
impoundment water, soils beneath impoundments, groundwater, surface water, surface and
subsurface soils, and structures located on the site. The study is scheduled for completion in 1991.
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.
Environmental Progress
The installation of a security fence and the ongoing cleanup and treatment of the surface
impoundments at the Broderick Wood Products site have reduced the potential for exposure to
hazardous materials while further investigations into the remaining contamination areas and cleanup
activities are taking place.
April 1991 26 BRODERICK WOOD PRODUCTS
-------
CALIFORNIA
COLORADO
EPA ID# COD980717938
EPA REGION 8
CONGRESSIONAL DIST. 05
Lake County
100 miles west of Denver
Site Description
The 130-year-old California Gulch site is a mining area covering 11 1/2 square miles of a watershed
area that drains along California Gulch to the Arkansas River. Starting in 1859, the area has been
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 supply, 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 cadmium, copper, lead, and zinc. The water in several shallow
groundwater wells in California Gulch and in some private wells has been shown to
exceed EPA drinking water standards for cadmium and zinc. Arsenic, cadmium, and lead
exist 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 for drinking.
27
April 1991
-------
Cleanup Approach
This site is being addressed in three stages: an immediate action and two long-term remedial phases
focusing on cleanup of the Yak Tunnel and cleanup of groundwater and surface water.
Response Action Status
Immediate Action: In 1986, EPA emergency workers extended public water supply
system lines to residences using private wells. In 1990, the 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 Gulch and 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 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 continuation in the summer of 1991. All cleanup activities are scheduled for
completion by the end of 1993.
Groundwater and Surface Water: The EPA began an investigation of mine wastes
at the site in 1987. The preliminary investigations are exploring the nature and extent of
the water pollution caused by mine tailings piles and ponds, smelter slags, and mine
waste dumps. Full-scale site investigations are scheduled to begin during the summer of 1991.
Environmental Progress
Extending the public water supply has provided safe drinking water for affected area residents.
Ongoing work to control surface runoff and to prevent further contamination from the California
Gulch site continues to provide environmental protection while permanent treatments are sought for
contaminated surface and groundwater.
April 1991 28 CALIFORNIA GULCH
-------
CENTRAL GIT
CLEAR CREEK
COLORADO
EPA ID#COD980717557
EPA REGION 8
CONGRESSIONAL DIST. 02
Clear Creek and Gilpin County
20 miles west of Denver
Other Names:
Argo Tunnel
Big Five Tunnel
Burleigh Tunnel
Central City Mining District
Gregory Incline
McClelland Tunnel
National Tunnel
Newhouse Tunnel
Quartz Hill Tunnel
Rockford Tunnel
Site Description
The Central City/Clear Creek site covers over 50 river miles in north central Colorado near
Central City and Idaho Springs. The site encompasses the Clear Creek drainage basin, which has
been affected by a number of inactive gold mines, including eight major areas that the EPA has
identified: Argo Tunnel, Big Five Tunnel, Burleigh Tunnel, McClelland Tunnel, and Rockford
Tunnel (all on Clear Creek); National Tunnel (on North Clear Creek); Gregory Incline (on North
Clear Creek); and Quartz Hill Tunnel (on North Clear Creek). The Clear Creek/Central City
Mining District contains numerous abandoned mine tailings and waste rock piles, mining
tunnels, and open shafts. The 4-mile Argo Tunnel, completed in 1904, drains water from
numerous inactive mines. The acidic water that drains from these mines contains various
dissolved heavy metals and flows from the tunnels into the creek and other tributaries feeding
into Clear Creek. During storms and annual snowmelts, water erodes the tailings piles, picks up
contaminants from the piles, and flows into the creeks. Clear Creek is an important source of
water to local industry, agriculture, and to people in the area who use it for drinking water and
recreation. In 1980, a sudden discharge or blow-out from the Argo Tunnel moved large amounts
of contaminants into Clear Creek, affecting users of the water farther downstream and
contaminating drinking water supplies. At the time the site was discovered, approximately 2,400
people lived in Gilpin County, and 7,308 people lived in Clear Creek County. The population of
this area increases slightly during the summer months due to tourism. Aquatic life in Clear
Creek is sparse for many miles both above and below the Argo Tunnel.
Site Responsibility: This site is being addressed through
Federal and State actions.
NPL LISTING HISTORY
Proposed Date: 07/23/82
Final Date: 09/08/83
29
ApriM991
-------
Threats and Contaminants
Soils, including tailings and waste rock, contain heavy metals such as arsenic,
cadmium, chromium, copper, and lead. Groundwater and surface waters contain
heavy metals. People can become exposed to site-related contaminants by
drinking contaminated water from private wells in the shallow and deep aquifers.
Children may also be at risk from coming into direct contact with contaminated
soil while playing on the tailings piles or on contaminated areas. The aquatic
environment has been and continues to be severely affected by Clear Creek and
the tributaries.
Cleanup Approach
The site is being addressed in four stages: immediate actions and three long-term remedial
phases directed at cleanup of the mine surface water discharge, tailings and waste rock, 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 Tailings. 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 water
from wells drilled into the shallow aquifer. Of the few such wells being used, only one showed
significant levels of contamination from cadmium. The EPA arranged to provide the home with
clean water from the Idaho Springs municipal water supply and provided the residents with bottled
water as an interim measure. The EPA connected four other 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.
Mine Discharge Treatment of Surface Water Contaminants: The EPA plans to
construct a wetland as a passive treatment system to treat mine tunnel discharge before
they reach surface waters. This is the preferred alternative and is contingent upon results
of pilot studies. The EPA already has constructed a pilot-treatment system to determine the ability
of passive treatment to meet water quality standards upstream from the site. If water quality
concentrations cannot be achieved by passive treatment, a combination system of passive and active
treatment systems using chemical or electrochemical precipitation will be constructed to treat mine
tunnel discharge. These systems will be designed to reduce the mobility, toxicity, or volume of
dissolved and suspended metals in the mine drainage, decrease the acidity of the mine drainage, and
meet the levels of water quality for waters upstream of the site. The State and the EPA currently are
carrying out the pilot program, and the State expects to complete the design for addressing
contamination of the site by early 1992.
April 1991 30 CENTRAL CITY-CLEAR CREEK
-------
Tailings/Waste Rock Remediation: The selected remedy involves stabilizing
the slope at five tailings and waste rock piles (Argo Tunnel, Gregory Incline, Big Five
Tunnels, Quartz Hill Tunnel, and National Tunnel) and adding diversion ditches to the
upslope side of the piles to provide drainage control. The remedy involves regrading portions of
the piles to stable configurations and placing large boulders at the base of the piles to minimize
erosion. 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
people or the environment. The tailings stabilization is complete at Argo Tunnel and the
Gregory Incline. The tailings stabilization procedure is being designed for the Big Five Tunnel,
the Quartz Hill Tunnel, and National Tunnel areas.
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 the
Argo Tunnel and focusing on the entire drainage basin for reducing or stopping water
from entering the tunnel. The state conducted an additional study, funded by the EPA through a
Cooperative Agreement, that was completed in the spring of 1990. A decision will be made on
the Argo Tunnel and the rest of the basin in late 1991, when the EPA study of the entire drainage
basin and the State study have been reviewed and have had an opportunity to undergo public
review and comment. As a result of its study, the State has identified three more tunnels and 15
more tailings piles that need to be addressed.
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 areas. The
Colorado Department of Health is leading all other cleanup actions.
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 waste pile across the ground at the Central City site.
The EPA provided affected residences with bottled water prior to hooking them up to the
municipal water supply and later connected four other residences to the city water supply. The
stabilization of the slope at the tailings and waste rock piles is underway, and remedies have
been chosen for the treatment of the acidic water. Studies on how to control blow-outs from
occurring and to reduce or stop water from entering the tunnel to prevent future contamination
currently are being conducted, as is a study to identify other sources of contamination and select
final cleanup remedies.
CENTRAL CITY-CLEAR CREEK 31 April! 991
-------
CHEMICAL S
COMPANY
COLORADO
EPAID#COD007431620
EPA REGION 8
CONGRESSIONAL DIST. 01
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 Adams
County Water and Sanitation District was found to be contaminated with organic chemicals. There
have been two 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.
NPL LISTING HISTORY
Proposed Date: 06/24/88
Final Date: 08/30/90
Threats and Contaminants
High concentrations of volatile organic compounds (VOCs), such as tetrachloroethylene,
were detected in groundwater samples. Sampling of a nearby drainage ditch by the
Colorado Department of Health detected the solvents methylene chloride and chloroform.
The EPA detected trichloroethylene (TCE) in soil in the northwestern corner of the
Chemical Sales Company site. 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 surface aquifer. Sand Creek is located near the site, but is not
affected by the observed contamination.
Cleanup Approach
The site is being addressed in four stages: immediate actions and three long-term remedial
phases focusing on controlling the source of contamination and cleanup of the groundwater and
the residential wells.
33
April 1991
-------
Response Action Status
Immediate Actions: 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 monitoring, Chemical Sales initiated an investigation in
1989 to determine where the contamination is coming from at the site and to identify
alternative technologies to control the sources of the contamination. The study,
completed in February 1991, recommends the following remedy: treating contaminated soils
through the use of soil vapor extraction and treating contaminated groundwater located near the
source through pump and treat systems and, possibly, air stripping. The EPA currently is reviewing
comments received during the public comment period. Following the review of the comments, the
EPA expects to select a cleanup strategy for the source control in 1991.
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 has proposed the
following remedy: the use of 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 EPA currently is reviewing comments
received during the public comment period and expects to select a cleanup strategy to address
groundwater contamination by mid-1991.
Residential Wells: In 1990, the EPA began an investigation to determine the extent of
contamination within the residential wells in the site area. 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 proposed connecting the affected residences to the South Adams County
Water and Sanitation District (SACWSD) water supply system. The EPA anticipates selecting the
cleanup strategy by following a review of comments received during the public comment period by
the end of 1991.
Site Facts: The EPA has entered into an Administrative Order on Consent with Chemical Sales,
requiring the company to conduct an investigation of site contamination and to identify alternative
technologies for the cleanup.
Environmental Progress
By removing drums containing hazardous materials and disposing of them at an approved facility
and securing the area, the EPA has reduced the threat of exposure to dangerous chemicals at the
Chemical Sales Company site. Further investigations leading to the selection of remedies for the
contaminated groundwater and control of the sources of contamination currently are underway.
April 1991 34 CHEMICAL SALES COMPANY
-------
DENVER RADI
COLORADO
EPAID#COD980716955
EPA REGION 8
CONGRESSIONAL DIST. 01
Denver County
Denver
Site Description
Forty-four properties in Denver are contaminated with radioactive sands and wastes 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 44, with 31 in the metropolitan Denver area. These 31 areas were
combined into 9 groups for cleanup activities including: (1) 12th and Quivas Properties; (2) 11th
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.
NPL LISTING HISTORY
Proposed Date: 10/23/81
Final Date: 09/08/83
Threats and Contaminants
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.
35
April 1991
-------
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. Workers expect to excavate 22,500 cubic yards of
contaminated soil and backfill with clean soil, regrading to the original contours. Where buildings
were constructed over contaminated soil, cleanup workers will remove the floors to excavate
underlying wastes, and then replace the floors. Cleanup was completed in April of 1991 and
reconstruction is scheduled for completion later in 1991.
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. Several contaminated buildings will be either decontaminated or demolished. The EPA
anticipates that 100,000 tons of contaminated material will be removed from the property and
replaced with clean fill, to be completed 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 both properties to the permanent disposal facility. The
wastes will be brought to the rail spur where workers will load them into sealed rail cars for transport
to a federally approved facility in western Utah. Cleanup activities began in 1989, with the
demolition of the contaminated brick building at 1298 S. Kalamath Street. Workers will excavate
51,000 cubic yards of contaminated soil, and they will either clean up or demolish contaminated
buildings. 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
features: (1) removing contaminated soil from the Robinson Brick Company 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. The EPA began two separate cleanup activities at this subsite in 1988.
Over 96,000 tons of contaminated waste was excavated and safely disposed of. The
decontamination work was completed in March 1991.
April 1991 36 DENVER RADIUM SITE
-------
Card Property: The EPA selected a remedy for this subsite in 1987 featuring: (1)
excavating 4,000 cubic yards of contaminated soil and sediments from the Card
property; (2) storing this waste in reinforced synthetic bags placed inside the True Truss
building and inside possible additions to the building; (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. The EPA began excavation
and disposal at contamination wastes in October 1990 and is scheduled to complete these cleanup
activities in September 1991. Delayed completion is likely as additional contamination was
discovered during cleanup, but the cleanup approach for this area is yet to be designed.
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 1991. Delayed completion of this phase of site cleanup is
possible, as additional contamination was discovered during initial excavations.
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 EPA has provided funding to the State to
conduct an in-depth investigation of the pollution problems at Shattuck Chemical
Company and the neighboring railroad property. The study will explore the nature and
extent of site contamination and will recommend the best strategies for cleanup. It is scheduled for
completion
in 1991.
ROBCO - Non-Radioactive Contamination: During the cleanup of radioactive
contamination at the ROBCO site, non-radioactive soil contamination was discovered.
The EPA is conducting an additional investigation to determine the nature and extent of
contamination and to identify cleanup alternatives. Preliminary studies have shown lead and arsenic
in the soil. The non-radioactive contamination is attributable to smelting of precious metals
conducted at the site in the late 19th century. Cleanup remedies are expected to be identified in
1991.
Environmental Progress
Extensive cleanup work has been completed at the Denver Radium Site, including the removal
and safe disposal of over 192,000 tons of contaminated materials. Additionally, cleanup actions
have addressed immediate sources of radon and have protected workers from long-term
exposure. Many additional actions currently are underway and are planned at the Denver
Radium Site, which will continue to reduce sources and levels of contamination.
DENVER RADIUM SITE 37 April 1991
-------
EAGLE MINE
COLORADO
EPAID#COD081961518
i i
EPA REGION 8
CONGRESSIONAL DIST. 03
Eagle County
8 miles west of Vail
Other Names:
New Jersey Zinc, Inc.
Gilman
Site Description
The Eagle Mine site includes the Eagle Mine workings, the town of Gilman, the mine tailings pond
areas, Rex Flats, 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. Mining
conditions and wastes form acid, which leaches toxic metals into surrounding surface water and
groundwater. Five major sources of contamination have been identified at the site: (1) ponds
containing tailings (mining wastes) cover 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 1,000 feet to the northeast.
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
L\
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 down gradient from the Eagle Mine site could pose
a health risk if used for human consumption. 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.
39
April 1991
-------
Cleanup Approach
This site is being addressed in two stages: initial and emergency actions and a long-term
remedial phase focusing on cleanup of the entire site.
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 Flats 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: (1) plugging the mine portals; (2) removing the roaster
piles, Rex Flats tailings, and tailings pile and consolidating them in the "new" tailings
pile; (3) capping the new pile and pumping groundwater; and (4) monitoring the Eagle River. To
prevent discharge of contaminated water to the river from the mine, the former owners have
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 have plugged the mine and reworked many millions of cubic
yards of mine tailings. They have consolidated approximately 90% of the wastes from the roaster
piles, Rex Flats, and the old tailings pile into the new tailings pile and are controlling groundwater in
the area. Workers have capped approximately 40% of the tailings. The state cleanup actions are
scheduled to be completed in 1994. However, the EPA currently is conducting further site
investigations due to the recent detection of mine leakages occurring through fractured rock.
Results of these investigations are expected in early 1992 and may result in additional cleanup
actions.
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% capped. A
groundwater extraction system is operational, and the mine is plugged and nearly completely
flooded. The EPA will, however, continue to treat water drainage and to monitor river impacts
while long-term remedial actions and additional site investigations are underway in order to protect
the Eagle River from contaminated runoff from the site.
April 1991 40 EAGLE MINE
-------
LINCOLN PARK
COLORADO
EPA ID# COD042167858
EPA REGION 8
CONGRESSIONAL DIST. 03
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
Groundwater underlying the mill area and the town 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. People who drink or otherwise come into
contact with contaminated well water may suffer 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.
41
April 1991
-------
Response Action Status
Entire Site: In 1988, the State, with the EPA's approval, selected a remedy to clean up
the site by: (1) hooking up area residences to an alternate water supply; (2) pumping and
treating the groundwater above the dam on Sand Creek to remove the contaminants; (3)
flushing the contaminants out of the water below the dam; (4) revegetating the site; (5)
implementing air quality controls; and (6) 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 1991. A risk study of the
site, to be completed in late 1991, will help the EPA determine the effectiveness of selected cleanup
remedies.
Site Facts: In 1987, the State and the Cotter Corporation signed a Consent Decree, under which
Cotter 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.
April 1991 42 LINCOLN PARK
-------
LOWRY LANDFILL
COLORADO
EPAID#COD980499248
EPA REGION 8
CONGRESSIONAL DIST. 04
Arapahoe County
2 miles east of Aurora
Other Names:
Lowry Disposal Area
City and County of Denver Landfill
Conoco 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 over 16 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 and undertook a preliminary cleanup in
1980. The wastes have migrated into the groundwater and surface water. Liquid wastes that reached
the land surface have formed a heavily contaminated stream flowing at peak rates of 16,500 gallons
per day. 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 Sand 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 and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date: 09/08/83
Final Date: 09/21/84
Threats and Contaminants
The air, shallow groundwater, sediments, soils, and surface water contain organic
chemicals, radionuclides/ionizing radiation, and inorganic chemicals. Although the
shallow groundwater 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 human health.
43
April 1991
-------
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 solids, landfill
gases, soils, surface water and sediments, 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, Denver began to shred the discarded tires that arc
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,
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 1992.
Landfill Solids: In 1990, the City of Denver, Waste Management of Colorado, and
Chemical Waste Management 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 waste
pit area. Once this study is completed in 1994, effective measures will be recommended to clean up
the refuse.
Landfill Gas: In 1990, the City of Denver, Waste Management of Colorado, and
Chemical Waste Management 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 1994.
Soils: The potentially responsible parties currently are investigating, under EPA
monitoring, the extent of soil contamination. This investigation is expected to be
completed in 1993.
Surface Water and Sediment: The potentially responsible parties are studying the
extent of the surface water and sediment contamination both on and off the site. The
study is scheduled to be completed in 1993.
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 1992.
April 1991 44 LOWRY LANDFILL
-------
Site Facts: In 1988, the EPA and 13 parties potentially responsible for the site contamination,
who refer to themselves as the Lowry Coalition, reached an agreement to investigate shallow
groundwater contamination at the site. In 1989, the parties agreed to broaden the investigation to
include deep groundwater. In March 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.
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.
LOWRY LANDFILL
45
April 1991
-------
MARSHALL LANDFILL
COLORADO
EPA ID# COD98049925
EPA REGION 8
CONGRESSIONAL DIST. 02
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; the first is an inactive 80-acre section
that served as a landfill, and the second is a 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 LISTING 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.
47
April 1991
-------
Response Action Status
x Immediate Actions: In 1984, Landfill, Inc. installed a 60-inch pressurized pipeline to
£* nrntp.rt Irval Hrinlfinrr water snnnlips hv transTWtinff thft wafpr arrncc thp landfill
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 of 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 contaminants to evaporate, and recapturing the contaminants in a
carbon filter before releasing the air) and discharging the treated water to Cowdery Drainage;
monitoring groundwater and surface water; and landfill improvements including regrading,
revegetating, digging of 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. The remaining cleanup activities
are included in the second design phase, with cleanup activities scheduled to be completed in late
1992.
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.
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.
April 1991 48 MARSHALL LANDFILL
-------
ROCKY FLATS PLANT
(USDOE)
COLORADO
EPA ID #007890010526
Site Description
EPA REGION 8
CONGRESSIONAL DIST. 02
Jefferson County
16 miles northwest of Denver
The Rocky Flats site covers 6,500 acres of United States Department of Energy (DOE) land.
Originally established by the Federal government in 1951, the facility currently is under contractor
management Rocky Flats produces plutonium triggers for the DOE nuclear weapons programs.
Site operations include recovering and reprocessing 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
are still used in the DOE's nuclear weapons production program. Since a 1989 FBI raid, plutonium
operations have been suspended pending the correction of the identified problems. A phased restart
of operations is planned for late 1991. Site contaminants have spilled onto the ground and into water
supply drainages. The DOE 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 LISTING 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. People could be exposed to chemicals on
site by touching, inhaling, or accidentally ingesting contaminants in soil, air,
groundwater, and surface water. Shallow groundwater in the southern section of the
site (the Hillside area) is contaminated with VOCs, which are excessively high for
this area.
49
April! 991
-------
Cleanup Approach
This site is being addressed in multiple stages: an immediate action and a total of 16 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; and Other Areas.
Response Action Status
Immediate Action: In 1987, the DOE removed more than 20,000 cubic yards of sludge
from evaporation ponds and conducted dewatering operations.
Hillside Areas: In 1988, the DOE completed the draft reports on the nature and extent of
contamination activities within the Hillside 881 area. Construction has begun on 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
DOE expects to begin treating the groundwater in 1992.
RO°J>I 903 Pad, East Trenches, and Mound Areas: This area is the most complex and
jfi;. 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 require
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 will
begin in the 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 that are used for irrigation and
as drinking water supplies for approximately 250,000 people, and land used for
recreational purposes. The DOE conducted two preliminary risk studies that will be used
as a focus for an investigation of these areas. A draft of the investigation work plan is expected in
mid-1991.
Solar Ponds: The DOE continues to operate a groundwater collection system. This has
effectively contained the contaminants until further action can be taken to assess and clean
up soils and groundwater. A work plan for an investigation of the area has been prepared
and is under review.
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 is under review.
Field work is expected to begin in late 1991.
April 1991 50 ROCKY FLATS PLANT (USDOE)
-------
Walnut Creek: The Walnut Creek Area encompasses the stream; numerous ponds;
disposal areas including an active landfill, 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 is under
review, and field work is scheduled to begin 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 is undergoing revisions before final acceptance.
Original Process Waste Lines: 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 is under review to determine the final study approach.
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.
Site Facts: The EPA, DOE, and the State signed an Interagency Agreement in January 1991. The
agreement outlines procedures and schedules for investigations of the 16 long-term remedial phases.
In May 1991, a Federal Facility Compliance Agreement was signed to achieve compliance with land
disposal restrictions.
Environmental Progress
Numerous actions and investigations currently are underway at the Rocky Flats Plant. The removal
of contaminated sludge and the dewatering operation have contained the spread of contaminants.
The construction for the cleanup of contaminated groundwater resources the site has begun, and
further cleanup activities are planned that will eliminate the potential for exposure to hazardous
substances at diverse areas of the site.
ROCKY FLATS PLANT (USDOE) 51 April 1991
-------
ROCKY MOUN
ARSENAL
COLORADO
EPAID#C05210020769
EPA REGION 8
CONGRESSIONAL DIST. 04
Adams County
10 miles 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 also 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 alluvial and bedrock aquifers. Old livestock wells on site
are being plugged and abandoned. 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 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: 07/01/87
53
April 1991
-------
Threats and Contaminants
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, accidental ingestion of 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 twenty-six stages: initial actions and twenty-five 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 also closed in 1986.
South Adams County Public Water Supply: The EPA connected 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 South
Adams County Water and Sanitation District with treated water.
M-1 Ponds and Pail Classification Yard: The following phases are in the
engineering design stage and are scheduled for completion in 1992: M-1 ponds
vitrification design; motor pool area vapor extraction system; Pail Classification Yard
groundwater intercept and treatment system; and Lime Settling Basins containment 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: hydrazine facility for disposal of liquid wastes and cleanup/
dismantling of the facility; wind-blown dust control reapplication; sanitary sewer closure; and
asbestos removal from the building.
April 1991 54 ROCKY MOUNTAIN ARSENAL
-------
Aquifers: The investigation determining the nature and extent of contamination of
an off-site area, south of 86th Avenue, affecting the South Adams County Water and
Sanitation District continues under the jurisdiction of the Chemical Sales Company
NPL Site.
Site Contamination: On-Site Contamination and Off-Site Contamination phases
are investigating the type and extent of contamination. The investigations will
include alternatives for final cleanup. The On-Site Contamination study is expected
to be completed in 1994 and the Off-Site Contamination study is scheduled for completion in
1993.
Groundwater Intercept and Treatment System: The technical specifications
for the groundwater intercept and treatment system off site, to the north of the
Arsenal, are expected to be completed in 1991.
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, 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 begin in 1991.
South Tank Farm: The South Tank Farm plume is under investigation, and an
implementation document allowing activities to occur, pending a final decision on
cleanup actions, is expected in 1991.
Army Trenches: A monitoring plan is ongoing and is re-evaluated annually to
determine if further action is necessary.
Shell Trenches: The containment system is under construction and is scheduled
for completion in 1991.
Northwest Boundary System: Improvements are ongoing, and the first stage is
expected to be completed in 1991. An interim document allowing site activities to
continue, pending a final remedy is expected for the second stage in 1992.
ROCKY MOUNTAIN ARSENAL 55 April 1991
-------
Treatment of Basin F Liquids: Construction of the incinerator for the treatment of
the liquids began in 1991. Incineration residues 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 and 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, installation of
transmission piping, and laboratory and office space will be constructed at the site to ensure that the
remedy operates effectively.
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.
Environmental Progress
Numerous initial and long-term cleanup actions have been performed or are currently underway at
the Rocky Mountain Arsenal site. The closing of the site, removal of contaminants, and the
provision of an alternative water supply have greatly 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 diverse site
contamination areas.
April 1991 56 ROCKY MOUNTAIN ARSENAL
-------
SAND CREEK
INDUSTRIAL
COLORADO
EPAID#COD980717953
Site Description
EPA REGION 8
CONGRESSIONAL DIST. 04
Adams County
Commerce City
Other Names:
L C Corporation
Colorado Organic Chemical Company
E. Holly & 48th St. Landfill
Browning Ferris/Globe Chemical
Colorado International Corporation
Private Brands Western, Inc.
The 500-acre Sand Creek Industrial site consists of four known sources of contamination, all of
which are now 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; an explosion in a
trench, which killed two men; an incident in which livestock were severely burned when they
wandered into acid pits; and a fire at the pesticide formulator, which 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 rubber-lined pits.
After the livestock were burned, lime was added and the pit area was covered. Acid was found to be
seeping from the pits into Sand Creek in 1976. In 1980, 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
Threats and Contaminants
The EPA conducted sampling at the site and found the soil, groundwater, and surface
water to be contaminated. Waste was discharged into Sand Creek. 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. People who accidentally come in direct contact with or ingest
contaminated groundwater, surface water, or soil may suffer adverse health effects. In
addition, people on site may be exposed by inhaling contaminated dust or vapors from
the soil.
57
April 1991
-------
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 EPA currently is
installing methane gas collection system at the Holly Landfill. Installation is scheduled to be
completed in mid-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 vacuum
pressure, 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.
COC Surface Soils: In 1990, the EPA selected a remedy to clean up COC surface soils
by soil washing and incineration 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 examine the feasibility of the soil washing process.
L.C. Corporation Acids Pits: In 1991, the EPA is scheduled to conduct studies to
determine the type and extent of acid contamination in the pits and the surrounding area.
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. Well sampling is underway. This study is
expected to be completed in 1992.
Groundwater: In 1991, the EPA is scheduled to conduct extensive studies of the
groundwater in the area to determine if there is a need for groundwater cleanup activities.
Gas at Holly Landfill: The EPA currently is investigating methods to reduce the gas
emissions emanating from the Holly Landfill. The investigation is scheduled to be
completed in' 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.
April 1991 58 SAND CREEK INDUSTRIAL
-------
Environmental Progress
The removal of drums and contaminated soil and the fencing of the area, as well as 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 taking place.
SAND CREEK INDUSTRIAL
59
April 1991
-------
SMUGGLER M
COLORADO
EPA ID# COD980806277
EPA REGION 8
CONGRESSIONAL DIST. 03
Pitkin County
1 mile northeast 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. Mine tailings from the site and mines in the area, as well as ancillary smelting
and milling operations, 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 mineral
exploration activities are still conducted on site. Tailings and mine wastes were spread downhill and
mixed with native soil, ore-bearing rock, and miscellaneous fill material. The total volume of waste
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 waste piles have been moved to the sides of developed areas
and remain as berms or mounds of contaminated soil. Portions of contaminated soil also have been
used for fill in some areas. The site is located in a residential area northeast of the City of Aspen,
which has a year-round population of approximately 4,500, as well as seasonal visitors. The City of
Aspen obtains drinking water from surface waters in the area. The nearest surface water is the
Roaring Fork River, approximately 1,000 feet downstream from the site.
Site Responsibility: The site is being cleaned up through a
combination of Federal 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 or touching
contaminated surface soils or vegetables grown in contaminated soils. The Roaring Fork
River is not likely to be a potential health risk to people.
61
April 1991
-------
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 the site and posted warning signs, as directed by the EPA. In
1990, the EPA excavated, removed, buried, and capped contaminated soil on two
residential properties.
Residential Areas: The remedy selected by the EPA in 1990 addresses contamination
impacts to residential areas near the site including: (1) construction of two cells for on-site
disposal of waste materials and relocation of the pipeline that passes through the Mollie
Gibson Park repository; (2) excavation of the top levels of soils and tailings in areas with high lead
concentrations, which will be overlain with a geo-textile liner, backfilled with clean fill, covered
with topsoil, and revegetated; and (3) operation and maintenance of the repositories to preserve the
integrity of an existing tailings cap within the residential areas. The EPA currently is designing the
technical specifications for the selected remedies. The design phase is scheduled to be completed in
1991. An irrigation pipeline currently is being relocated in order to prepare the repository and is
expected to be completed in 1991. Cleanup on the properties also is scheduled to begin in mid-1991
and is expected to continue into 1992.
Mine Area: The EPA currently is conducting an additional study of the nature and extent
of contamination at the Smuggler-Durant Mine area, including possible contamination of
groundwater underlying the site. The study will define the contaminants and will
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 the site and excavating, removing, and capping contaminated soil
have reduced the threat of direct contact with contaminants while final remedies are being designed
to restore the residential area and additional studies are being conducted at the Smuggler Mountain
site.
April 1991 62 SMUGGLER MOUNTAIN
-------
URAVAN URANIUM
PROJECT
CARBIDE CORP.)
COLORADO
EPA ID# COD007063274
EPA REGION 8
CONGRESSIONAL DIST. 03
Montrose County
90 miles southwest
of Grand Junction
Other Names:
Uravan Uranium Mill Operations
Uravan Uranium Mill Town
UMETCO
Site Description
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.
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. Radon gas emanates from the
eroding tailings piles. The Town of Uravan was established in 1935 to house the workers at the mill
and mine facilities and no longer exists.
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
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.
63
April 1991
-------
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.
The features of this remedy include: (1) reclaiming nearly 10 million cubic yards of
radioactive tailings by capping and revegetation; (2) constructing a disposal system for
radioactive crystals; (3) placing 1 1/2 million cubic yards of waste found along the San Miguel River
in a secure disposal area; (4) excavating contaminated soil and placing it in an approved landfill; and
(5) 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 and to 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.
ApriM991 64 URAVAN URANIUM PROJECT
(UNION CARBIDE CORP.)
-------
WOODBURY CHEMICAL
COMPANY
COLORADO
EPA ID# COD980667075
EPA REGION 8
CONGRESSIONAL DIST. 04
Adams County
Commerce City
Site Description
The 5-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
panics' actions.
NPL LISTING 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 contain
chlorinated pesticides and heavy metals. Potential health risks may exist for
individuals accidentally ingesting or coming in direct 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 cleanup of the entire site.
65
April 1991
-------
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 at the site. All contaminated soil, originally meant to be addressed in this cleanup action, is
now being addressed in the next phase. The engineering design for cleanup of the rubble piles is
anticipated to be completed in 1991.
Entire Site: In 1989, the EPA selected a remedy for cleanup of the remainder of the site,
which includes 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 technologies to be used began in 1990 and is
scheduled to be completed in mid-1991. This work is being conducted by the parties potentially
responsible for the contamination, under EPA monitoring. Cleanup of the site is expected to begin
immediately following the completion of the engineering design.
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,
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 a portion of the past costs.
Environmental Progress
The actions to prevent access to the site and to prevent additional surface water runoff have reduced
the potential for exposure to contaminated materials at the Woodbury Chemical Company site while
cleanup activities are being designed.
April! 991 66 WOODBURY CHEMICAL COMPANY
-------
APPENDIX A
Glossary:
Terms Used
in the
Fact Sheets
67
-------
GLOSSARY
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.
Terms Used
in the NPL
Book
Acids: Substances, characterized by low pH
(less than 7.0), that are used in chemical
manufacturing. Acids in high concentration
can be very corrosive and react with many
inorganic and organic substances. These
reactions possibly may create toxic com-
pounds 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).
Aeration: A process that promotes break-
down of contaminants in soil or water by
exposing them to air.
Agency for Toxic Substances and Disease
Registry (ATSDR): The Federal agency
within the U.S. Public Health Service charged
with carrying out the health-related responsi-
bilities of CERCLA.
Air Stripping: A process whereby volatile
organic chemicals (VOCs) are removed from
contaminated material by forcing a stream of
air through it in a pressurized 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.
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% or more of the drinking water of
an area.
Artesian (Well): A well made by drilling
into the earth until water is reached, which,
from internal pressure, flows up like a foun-
tain.
69
-------
GLOSSARY.
Attenuation: The naturally occurring pro-
cess by which a compound is reduced in
concentration over time through adsorption,
degradation, dilution, and/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 remov-
ing 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, form-
ing salts.
Benin: A ledge, wall, or a mound of earth
used to prevent the migration of contami-
nants.
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 contami-
nated 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
elsewhere.
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
groundwater 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 or-
ganic 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 Environ-
mental Response, Compensation, and Liabil-
ity Act].
Characterization: The sampling, monitor-
ing, and analysis of a site to determine the
70
-------
GLOSSARY
extent and nature of toxic releases. Character-
ization provides the basis for acquiring the
necessary technical information to develop,
screen, analyze, and select appropriate
cleanup techniques.
Chemical Fixation: The use of chemicals to
bind contaminants, thereby reducing the
potential 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 interchangeably 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. 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 communica-
tion with the public. Goals of community
relations programs include creating an under-
standing of EPA programs and related ac-
tions, assuring public input into decision-
making processes related to affected commu-
nities, and making certain that the Agency is
aware of, and responsive to, public concerns.
Specific community relations activities are
required in relation to Superfund cleanup
actions [see Comment Period].
Comprehensive Environmental Response,
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 to-
gether.
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 and/or the costs incurred by the
government that the parties will reimburse, as
well as the roles, responsibilities, and enforce-
ment options that the government may exer-
cise in the event of non-compliance by poten-
tially responsible parties. If a settlement
between the EPA and a potentially respon-
sible party includes cleanup actions, it must
be in the form of a Consent Decree. A Con-
sent 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 struc-
ture, typically in a pond or a lagoon, to pre-
vent the migration of contaminants into the
environment.
71
-------
GLOSSARY.
Contaminant: Any physical, chemical,
biological, or radiological material or sub-
stance 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 radioactive
materials into the environment.
Cooperative Agreement: A contract be-
tween 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 of water into
the waste and to prevent erosion that could
cause the movement of contaminants.
Creosotes: Chemicals used in wood preserv-
ing operations and produced by distillation of
tar, including polycyclic aromatic hydrocar-
bons and polynuclear aromatic hydrocarbons
[see PAHs and PNAs]. Contaminating
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
embankment.
Decommission: To revoke a license to
operate and take out of service.
Degradation: The process by which a
chemical is reduced to a less complex form.
Degrease: To remove grease from wastes,
soils, or chemicals, usually using solvents.
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 de minimis contributors, as a single
group rather than as individuals, saving time,
money, and effort.
Dewater: To remove water from wastes,
soils, or chemicals.
Dike: A low wall that can act as a barrier to
prevent a spill from spreading.
Disposal: Final placement or destruction of
toxic, radioactive, or other wastes; surplus or
banned pesticides or other chemicals; polluted
soils; and drums containing hazardous materi-
als. Disposal may be accomplished through
the use of approved secure landfills, surface
impoundments, land farming, deep well
injection, or incineration.
Downgradient: A downward hydrologic
slope that causes groundwater to move toward
lower elevations. Therefore, wells
downgradient of a contaminated groundwater
source are prone to receiving pollutants.
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
facilities.
Emulsifiers: Substances that help in mixing
materials that do not normally mix; e.g., oil
and water.
72
-------
GLOSSARY
Endangerment Assessment: A study con-
ducted 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; and/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 Recovery].
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
nearshore 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; together,
they are commonly referred to as the Rl/FS
[see Remedial Investigation].
Filtration: A treatment process for removing
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.
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
73
-------
GLOSSARY.
and willingness to perform a site study or
cleanup.
Groundwater: Underground 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. It possesses at
least one of four characteristics (ignitability,
corrosivity, reactivity, or toxicity), or appears
on special EPA lists.
Hot Spot: An area or vicinity of a site con-
taining exceptionally high levels of contami-
nation.
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 con-
trolled 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 precipitation
(rain or snow) or from application of waste-
water 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 substances
of mineral origin, not of basic carbon struc-
ture.
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,
74
-------
GLOSSARY
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 and/or
incorporate 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 chemical landfills are disposal sites for
hazardous waste. They are designed to
minimize the chance of release of hazardous
substances into the environment [see Re-
source Conservation and Recovery Act].
Leachate [n]: The liquid that trickles
through or drains from waste, carrying soluble
components from the waste. Leach, Leach-
ing [v.t.]: The process by which soluble
chemical components are dissolved and
carried through soil by water or some other
percolating liquid.
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 com-
plexity, site cleanup activities can be sepa-
rated into several of these phases.
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,
contaminants, 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 control-
ling 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
75
-------
GLOSSARY.
which groundwater flows and the types and
amounts of contaminants present.
National Priorities List (NPL): The EPA's
list of the most serious uncontrolled or aban-
doned hazardous waste sites identified for
possible long-term cleanup under Superfund.
The EPA is required to update the NPL at
least once a year.
Neutrals: Organic compounds that have a
relatively neutral pH, complex structure and,
due to their organic bases, are easily absorbed
into the environment. Naphthalene, pyrene,
and trichlorobenzene 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 poten-
tially responsible parties, although the EPA
may undertake certain investigatory and
planning activities. The 60-day period may
be extended if the EPA receives a good faith
offer within that period.
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, hydro-
gen, 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 is 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.
Petrochemicals: Chemical substances
produced from petroleum in refinery opera-
tions and as fuel oil residues. These include
fluoranthene, chrysene, mineral spirits, and
refined oils. Petrochemicals 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
poisonous.
76
-------
GLOSSARY
Physical Chemical Separation: The treat-
ment process of adding a chemical to a sub-
stance 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 deter-
mine its ability to clean up specific contami-
nants.
Plugging: The process of stopping the flow
of water, oil, or gas into or out of the ground
through a borehole or well penetrating the
ground.
Plume: A body of contaminated groundwater
flowing from a specific source. The move-
ment of the groundwater is influenced by such
factors as local groundwater flow patterns, the
character of the aquifer in which groundwater
is contained, 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.
Polycyclic 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 creo-
sotes 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 caulk-
ing 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 Sub-
stances Control Act
Polynuclear Aromatic Hydrocarbons
(PNAs): PNAs, such as naphthalene, and
biphenyls, are a group of highly reactive
organic compounds that are a common com-
ponent of creosotes, which can be carcino-
genic.
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 con-
centrations 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, including owners, who may have
contributed to the contamination at a
Superfund site and may be liable for costs of
response actions. Parties are considered PRPs
until they admit liability or a court makes a
determination of liability. PRPs may sign a
Consent Decree or Administrative Order on
Consent to participate in site cleanup activity
without admitting liability.
Precipitation: The removal of solids from
liquid waste so that the solid and liquid
portions can be disposed of safely; the re-
moval of particles from airborne emissions.
Electrochemical 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 informa-
tion about a known or suspected waste site or
release to determine if a threat or potential
threat exists.
77
-------
GLOSSARY.
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 environment. 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. Radia-
tion also occurs naturally through the break-
down of granite stones.
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.
Record of Decision (ROD): A public docu-
ment 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 construc-
tion 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 contami-
nation at a Superfund site, establish the
criteria for cleaning up the site, identify the
preliminary alternatives for cleanup actions,
and support the technical and cost analyses of
the alternatives. The remedial investigation
is usually done with the feasibility study.
Together they are customarily referred to as
the RI/FS [see Feasibility Study].
Remedial Project Manager (RPM): The
EPA or State official responsible for oversee-
ing cleanup actions at a 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 with-
out 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 remain-
ing in the environment after a natural or
technological process has taken place, e.g.,
the sludge remaining after initial wastewater
treatment, or particulates remaining in air
after the air passes through a scrubbing, or
other, process.
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
78
-------
GLOSSARY
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 to store
waste.
Riparian Habitat: Areas adjacent to rivers
and streams that have a high density, diver-
sity, and productivity of plant and animal
species relative to nearby uplands.
Runoff: The discharge of water over land
into surface water. It can carry pollutants
from the air and land and spread contamina-
tion from its source.
Scrubber: An air pollution 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.
Seeps: Specific points where releases of
liquid (usually leachate) form from waste
disposal areas, particularly along the lower
edges of landfills.
Seepage Pits: A hole, shaft, or cavity in the
ground used for 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
necessary for choosing and designing cleanup
measures 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 subsur-
face 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 smelt-
ers 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
79
-------
GLOSSARY.
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
approaches: dissolving or suspending them in
the wash solution for later treatment by
conventional methods, and concentrating
them into a smaller volume of soil through
simple particle size separation techniques [see
Solvent Extraction].
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 hazard-
ous constituents. Mobility is reduced through
the binding of hazardous constituents into a
solid mass with low permeability and resis-
tance to leaching.
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 at-
tracting substances. It is used in many pollu-
tion control systems.
Stillbottom: Residues left over from the
process of recovering spent solvents.
Stripping: A process used to remove volatile
contaminants from a substance [see Air
Stripping].
Sumps: A pit or tank that catches liquid
runoff for drainage or disposal.
Superfund: 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
releases of hazardous substances that may
endanger public health, welfare, or the envi-
ronment. 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, includ-
ing 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 Wet-
lands].
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
80
-------
GLOSSARY
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 contami-
nated areas and, therefore, are not prone to
contamination 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.
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
potentially toxic chemicals are used as sol-
vents, degreasers, paints, thinners, and fuels.
Because of their volatile nature, they readily
evaporate into the ah-, 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 pollutants 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.
81
-------
APPENDIX B
Information
Repositories
for
NPL Sites
in Colorado
83
-------
itory
ntity
f the
s,
ac
n rel
pert
and
lic
nters
ti
mi
ic i
obta
ll pu
ds o
Repository
Si
.£
S
CN
O
oo
8
S
1
Broadway
r~
>n
en
1
J
Denver Public Library, Central
Street, Commerce City, CO 80022
|
1
oo
B
s
«
u
<
|
ON
Idaho Springs Public Library, 2
Not Established
1
00
8
i
1
Broadway
r-
VI
en
£
jjj
Denver Public Library, Central
i
oo
o
U
.S
S
of
s
oo
(X
es
o
"3
i
Town Clerk's Office, Minturn 1
ts
Canon City Library, 516 Macoi
cs
8
oo
o
O
rf
I
u
I
cd
o
a
u
Os
^
i
^
a
I
u
|
u
1
cd
|
1
oo
o
U
tS
'>
VI
'3
2
*s
ai
I
00
Louisville Library, 950 Spruce
5 West 1 12th Avenue, Westminster, CO 800!
en
I
0
on
00
1
4
Broadway
m
CO
1 <
J
Denver Public Library, Central
i Street, Commerce City, CO 80022
§
§
oo
ty Branch,
U
u
g
a
£
o
IB
a
1
3
c
o
'3
CQ
'i
OS
c
Colorado State Health Departm
i Street, Commerce City, CO 80022
S
o
oo
n
u
QJ
a
V
o
U
Adams County Public Library,
a «
a
s
ary
tati
a
(A
E
R
lo
PARK
, _ K U <
U U U Q W
U.S. G.P.O.:1992-311-893-60427
85
------- |