PB98-963150
EPA 541-R98-176
March 1999
EPA Superfund
Explanation of Significant Difference
for the Record of Decision:
Lowry Landfill
Aurora, CO
10/24/1997
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION VIII
999 18th STREET - SUITE 500
DENVER, COLORADO 80202-2466
February 12, 1998
Subject: Responsiveness Summary for the Second Explanation of Significant
Differences, Lowry Landfill Superfund Site
Dear Sir/Madam:
Please be advised that there is an error within Attachment E (Technical Evaluation of
Proposed Ground-Water Treatment and Disposal Alternatives) of the above-referenced
document. The mistake was recently brought to my attention by the Citizens for Lowry
Landfill Environmental Action Now (CLLEAN). The evaluation table, which summarizes
the rankings of the two cleanup alternatives, failed to include numerical values for State
Acceptance and Community Acceptance.
This was an unintentional mistake and I take complete responsibility for the mixup.
Enclosed is a copy of the table as it should have appeared in Attachment E. Copies of this
errata sheet are being mailed to all recipients of the Responsiveness Summary.
The corrected ratings for State Acceptance and Community Acceptance are now
consistent with the existing text on page 8 of Attachment E of the Responsiveness
Summary. I believe the existing text adequately reflects the community's stated opposition
to Alternative 1 and preference for Modified Alternative 2B.
If you know of anyone who may have previously received a copy of the Responsiveness
Summary but did not receive the enclosed, corrected table, please either pass on a copy
to them or have them contact me. If you have any additional questions, I can be reached
at 1-800-227-8917 (extension 6724) or 303/312-6724.
Sincerely,
Marc E. Herman
Remedial Project Manager
Lowry Landfill Superfund Site
Enclosure
Printed on Recycled Paper
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10
EPA Assessment Criterion
1. Overall Protection of Human Health & the Environment
2. Compliance with ARARs
3. Long-Term Effectiveness and Permanence
4. Reduction of TMV Through Treatment
5. Short-Tcrm Effcciiveness .
6. Implcmcntability
7. Cost
8. State Acceptance
9. Community Acceptance
Total Score
Alternative 1
5
5
3
4
3
5
4
5
1
35
Modified Alternative 2B
5
5
2
3
3
3
2
4
5
32
Note: 5 = completely achieves the objectives of the criterion; 1 = minimally achieves the objectives of the criterion
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Responsiveness Summary for the
Second Explanation of Significant Differences
Lowry Landfill Superfund Site
ARCS Contract No. 68-W6-0036
EPA Work Assignment No. 016-ROBF-0808
CH2M HILL Master Project No. 139814
DCN 97-456
Volume I of II
Prepared for
U.S. Environmental Protection Agency
Prepared by
CH2M HILL
October 1997
H:\DA\WORDPWIN\005.WPD
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Preface
DENDividrs2.doc/l
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Preface
(How to Find Your Letter)
More than 400 letters with comments were submitted to the United States Environmental
Protection Agency (EPA) during the public comment period on the Lowry Landfill Superfund
Site Second Explanation of Significant Differences. This Responsiveness Summary document
provides responses to all of the comments and questions received in those letters and other
communications during that period. This preface explains how to find a particular letter within
this two-volume document.
This document is composed of the following two volumes:
Volume I
Preface
Executive Summary
Comment Letters Index
Acronyms and Abbreviations
Responses
References
Glossary
Attachments
Volume II
Preface
Comment Letters Index
Copies of the original comment letters
To find a particular letter in this docurnent, go to the Comment Letters Index that follows the
Executive Summary in Volume I and this Preface in Volume El and search for the last name of
the person who signed the letter. The Comment Letters Index is arranged alphabetically by the
last name of the persons who signed the letters. In some cases, signatures on some of the letters
were not legible. Because other copies of the form letters were available, these illegible
signatures are not included in the Comment Letters Index, but copies of the form letters with the
illegible signatures are included in Volume EL
The Comment Letters Index is divided into three columns. The first column is arranged
alphabetically by last name. The second column provides the page number in Volumn El where a
copy of the original letter the person signed can be found. The third column provides the page
number in Volume I where the responses to the letter(s) the person signed can be found. In some
cases, the same person sent in more than one letter. In these instances, there are multiple page
numbers listed in the second and third columns.
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A number of questions repeated frequent themes. The Executive Summary presents general
responses to these frequently asked questions.
Some of the responses in the document refer the reader to specific sections of the Executive
Summary so that the response is complete. When a response says (see Executive Summary -
Sludge/Biosolids), this means the reader is referred to the section in the Executive Summary with
the heading "Sludge/Biosolids." Additionally, the Executive Summary contains an overview of
the Lowry Landfill Superfund Site history and a description of the Publicly Owned Treatment
Works option. '
Upon receipt of all of the comments at the close of the public.comment period, EPA and the
Colorado Department of Public Health and Environment (CDPHE) carefully reviewed and
evaluated each comment. Based on this review and thoughtful consideration, EPA and CDPHE
developed a response to each comment. These responses are presented in Volume I.
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Executive Summary
DENDividrs2.doc/I
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Executive Summary
Responsiveness Summary
for the
Lowry Landfill Superfund Site
Second Explanation of Significant Differences
October 1997
Introduction
In accordance with the requirements of the
Comprehensive Environmental Response,
Compensation, and Liability Act' of 1980, as
amended (CERCLA), 42 U.S.C. 9601.etseq..
and the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40 C.F.R.
Part 300, et sco,., this responsiveness summary
presents the response of the United States
Environmental Protection Agency (EPA) and the
Colorado Department of Public Health and
Environment (CDPHE) to public comments
received on the Second Explanation of
Significant Differences (ESD), dated March
1997. The comments were received during the
public comment period that extended from March
24 through June 30, 1997. Community members
submitted comments on the proposed changes to
the Record of Decision (ROD) for the Lowry Landfill
County, Colorado.
The purpose of this executive summary is to
provide:
1. An overview of the site history and status;
2. A summary of the approved changes in the
Second ESD; and
3. Responses to the issues raised most
frequently in the comments.
Each comment is responded to in detail within
the body of the Responsiveness Summary. To
conserve paper, space, and money, copies of the
complete Responsiveness Summary are available
at the locations listed on the last page of this
executive summary.
Superfund Site (Lowry Site or Site) in Arapahoe
More than 400 written comments were received on the ESD in addition to the comments received during
the public meeting held on April 2, 1997. All of these comments have been responded to in the
Responsiveness Summary, which consists of this Executive Summary, Volume I, which contains the
responses, and Volume II, which contains copies of the original letters.
The purpose of this executive summary is to provide an overview of the site history and status, a summary
of the proposed and now approved changes in the Second ESD, and address the issues that were most
frequently raised in the comments. More detail on each of the topics raised in this Executive Summary can
be found in the responses to comments in Volume I. Each comment is responded to in detail in the body
of the complete Responsiveness Summary.
Boldcd terms are defined in the Glossary.
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Contents
Q Summary of Site History and Contamination Problems page 2
Q Summary and Status of Selected Sitewide Remedy page 3
Q Description of the Second Explanation of Significant Differences (ESD) page 4
Q Public Comments Overview page 6
Summary of Site History and Contamination Problems
The Lowry Site is located northeast of the
intersection of Quincy Avenue and Gun Club
Road, approximately 15 miles east of the City
and County of Denver (Denver), Colorado. In
the late 1930s, Denver bought 60,000 acres of
land (the Lowry Site comprises about 480 acres
of this land) to attract an Army Air Corps
Technical School to Denver. In 1939, the
Denver City Council transferred the land to the
Federal government. From about 1940 to 1962,
the United States Air Force used the land as a
bombing range. In 1964, the United States
transferred portions of the bombing range back
to Denver.
From 1966 until 1980, Denver operated a
landfill at Section 6 on the Lowry Site, taking in
liquid and solid household and industrial
wastes. These wastes included hazardous
substances, such as volatile organic
compounds and inorganics. Organic
compounds contain the element carbon.
Examples of organic compounds include
petroleum products, solvents, and pesticides.
Volatile organic compounds are organic
compounds that tend to evaporate easily.
Inorganic compounds include metals (such as
arsenic and selenium), chlorides, and sulfates.
IAST OUISCV AVtMUt
E/VW Slimy W.ll
Over 120 million gallons of liquid waste were
disposed of at the Lowry Site, primarily using a practice known as "co-disposal." Some 75 unlined waste
pits or trenches were dug to hold the mixed household and industrial wastes. In the southern half of the
Lowry Site, the pits were filled with liquid wastes and then covered with 25 to 60 feet of household waste.
The waste pits were about 15 to 30 feet deep, about 100 to 1,100 feet long, and about 50 to 150 feet wide.
Over time, the liquids seeped out of the pits and mixed with the household waste and ground water. In
the central part of the Lowry Site, the pits were filled with liquid wastes and household waste, then covered
with 2 to 5 feet of soil and used tires. Over time, these liquid wastes seeped into the ground water and into
DEN/H/DA/WORDPWIN/09.VWPU
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Unnamed Creek. Approximately 8 million tires were brought to the Lowry Site in the 1970s. These tires
were later shredded and placed in a monofill onsite.
From 1969 until 1986, about 37 million gallons of sewage sludge were spread on 160 acres of land along
the northern and eastern areas of the Lowry Site and mixed into the soils. After 1980, liquids collected in
surface ponds onsite were injected in the same 160-acre area. Both the sewage sludge and the collected
liquid contained hazardous substances.
The Lowry Site was placed on the National Priorities List (NPL) in September 1984. Studies performed
prior to 1984 found contaminants in surface water and sediments, ground water, soils, and landfill solids.
From 1984 to 1993, a series of Remedial Investigations/Feasibility Studies (Rl/FSs) were conducted to
find out how much and what types of contamination were at the Lowry Site. Also, the studies evaluated
the potential threats to human health and the environment posed by the Site.
The main threats at the Lowry Site are posed by: landfill gas; waste-pit liquids; contaminated ground
water; buried drums and their contents; and contaminated soils within the former tire pile area (FTPA).
The Lowry Site ROD was issued by EPA and CDPHE on March 10, 1994, and contains the sitewide
cleanup plans for the Lowry Site.
On November 18, 1994, EPA issued a Unilateral Order for Remedial Design/Remedial Action (RD/RA
Order) to 34 Potentially Responsible Parties. The RD/RA Order directs these parties to develop a remedial
design for the sitewide remedy and to perform the remedial action. Three of the parties (Denver, Waste
Management of Colorado, Inc., [WMC] and Chemical Waste Management, Inc. [CWM]), referred to as
the Respondents to the RD/RA Order, have reached agreements with 23 other parties to perform the RD
and the RA on their behalf.
In August 1995, EPA and CDPHE issued the First ESD to clarify and correct some minor details of the
remedy.
In March 1997, EPA and CDPHE proposed a second set of changes to the ROD, referred to as the Second
ESD. These changes to the ROD resulted from new information that EPA and CDPHE received after
issuing the ROD. The new information included the results of treatability studies performed by the
Respondents and the potential impact of the construction of a sanitary sewerline about a half mile west of
the Lowry Site.'
Summary and Status of Selected Sitewide Remedy
The ROD states that contaminated ground water will be contained and collected using: the existing
underground clay barrier wall and the Surface Water Removal Action collection system; underground
bentonite slurry walls on the eastern, southern, and western boundaries of the Lowry Site; and a ground-
water collection trench to be located at the northern boundary of the landfill mass. Contaminated ground
water will be treated at the existing onsite treatment plant or an upgraded facility. Landfill gas will be
contained, collected, and treated using an enclosed flare (a large open-flame burner housed in a four-sided
metal container). The cleanup in the FTPA will address principal threats (buried drums, drum contents,
and contaminated soils) through treatment and offsite disposal. Landfill solids and soils will be contained
onsite. The revisions to the ROD in the Second ESD do not change the overall approach of the sitewide
cleanup plans.
DEN/H/DAAVORDPWIN/095.WPI) 3
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Description of the Second Explanation of Significant Differences (ESP)
Highlights of the differences are as follows:
1. Former Tire Pile Area. The ROD states that buried drums, drum contents, and contaminated
soils in the FTPA will be excavated and transported qffsite for treatment and disposal. The Second
BSD requires that these contaminated materials be treated and disposed of onsite.
As part of remedial design, EPA performed _ r,,-,^ .
u. c . u-i . . .iT The approved change to the ROD is that the
oversight of treatabihty tests on the . *v 6 . ....
.... . , f ., buned drum contents and contaminated soils in
contaminated materials excavated from the r~m>A -n L. j n j
TTTOA TU . . A* i , ,u the FTPA will be treated using controlled
FTPA. These tests were used to evaluate the . ... , , .
..... r . ... . , , aeration and disposed or onsite.
possibility of treating and disposing of the _
contaminated materials onsite. The two ^^^^^^^^^^^^^^^^^^^^^^^^^
treatability tests were: air drying (controlled
aeration); and, enhanced bioremediation (natural decay process). For the air drying test, covered
stockpiles of soils/sludges were allowed to dry in a controlled manner. Air emissions data were
collected and will be used to design emissions monitoring. Enhanced bioremediation is a process in
which chemical-consuming bacteria are used to degrade organic compounds. For this test,
soils/sludges were mixed with bacteria. Organic compound degradation was enhanced by regulating
the amount of oxygen and nutrients, and the temperature.
Based on the treatability tests, controlled aeration met the remedial action objectives for the FTPA
soils. To dispose of the contaminated materials onsite, these materials will be treated, using controlled
aeration, to meet requirements of the Federal Solid Waste Disposal Act and the Colorado Hazardous
Waste Act.
2. Contaminated Ground Water. The ROD states that contaminated ground water shall be
treated at either: (1) a newlyrbuilt onsite treatment plant; or (2) the existing plant, which would be
upgraded.
The Second ESD requires that contaminated . .. ..
, . j The approved change to the ROD is that the
ground water be treated onsite to remove ... . .. j «
0 . , . . Tt_ j water would be pretreated and then piped ofrsite
organics from the ground water. The approved /. , Y Y .
,° . .-,?. . u 'j for treatment of inorganic and remaining organic
change to the ROD is that the pretreated water . 6 " &
.* . . . , - . f . . . f contaminants.
would then be piped offsite for treatment of L^^__^^___^_____^^^_^______-11__
inorganic and remaining organic contaminants ^^^^^^^^^^^^^^^^^^^^^^^^^^^^«
at the Metro Wastewater Reclamation District
(Metro) facility, a Publicly Owned Treatment Works (POTW) and the City of Aurora Sand Creek
Wastewater Reclamation Facility (also a POTW).
The POTWs will issue enforceable discharge permits to the Respondents to the RD/RA Order to control
the quality of the pretreated water to be discharged to the sewer system. The permits will require that the
pretreated water discharged to the POTWs meet specific chemical standards, in accordance with the
National Pretreatment Program requirements of the Clean Water Act of 1977, as amended (CWA).
Chemical-specific limits will be established to ensure that the pretreated ground water from the Lowry Site
will:
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Q Comply with state water quality standards
Q Achieve effluent concentration limits developed by EPA for pollutants not regulated by water quality
standards
Q Maintain "exceptional quality" sludge levels of pollutants in the POTWs' products
Q Prevent interference with the POTWs' treatment processes
Q Restrict releases of hazardous air pollutants from the POTWs' facilities
Q Protect workers from adverse health and safety effects caused by the presence of toxic and reactive
gases in the sewer system
In April 1996, the Respondents to the RD/RA Order evaluated options for treating contaminated ground
water at the Lowry Site:
Alternative 1 (POTW option) included onsite pretreatment for organic contaminants, likely
using the systems that are currently in place, followed by offsite treatment of inorganic contaminants
and remaining organic contaminants at the Metro POTW. Because this option would remove water
from the shallow ground-water system along Unnamed Creek, the water would have to be replaced or
augmented with clean water from another source. This alternative was amended to include treatment
of some of the pretreated ground water by the City of Aurora's Sand Creek Wastewater Reclamation
Facility.
Modified Alternative 2B (Onsite Treatment-Reverse Osmosis/Evaporation)
included: (1) onsite treatment of organic contaminants; and, (2) onsite treatment of inorganics, using a
two-stage reverse osmosis, followed by evaporation and recovery of the evaporated water. Modified
Alternative 2B also included offsite disposal of evaporator sludges and discharge of the recovered
water to the wetlands. This alternative would also require some ground-water augmentation (addition
of clean water from another source). It would require less augmentation than Alternative 1, but some
water would be lost in the treatment process.
Alternatives 2A (Onsite Treatment-Reverse Osmosis) and 2C (Onsite Treatment-
Evaporation) were evaluated and eliminated from further consideration based on the nine NCP
criteria.
Several years ago, the POTW option was evaluated as part of the feasibility study for the shallow and deep
ground-water operable units. At that time, the nearest interceptor was several miles away, and it was not
practical to build a sewer line to transfer the pretreated water to the POTW. The City of Aurora recently
indicated that it will allow connection of the discharge line from the Lowry Site to a newly constructed
sewer line. The City of Aurora also stated that it will allow pretreated Lowry Site water to be conveyed
through the sewer line to the Metro and Aurora POTWs. Metro and Aurora have indicated that they will
accept pretreated Lowry Site water for final treatment, provided the water has been pretreated to meet
established standards.
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Pros and Cons of the Two Options
The advantages of Alternative 1 (POTW option) are that this alternative is the most technically feasible,
cost-efficient, protective, and reliable option. The sewer line is already in place and the onsite treatment
plant and POTWs are operational and reliable. The disadvantage of Alternative 1 is that water
augmentation is required.
The advantage of Modified Alternative 2B is that less water augmentation is required. However, Modified
Alternative 2B uses more complex processes that may be less reliable. In addition, evaporator sludges
would be generated that would require offsite disposal and treatment.
Although both options would be effective and would comply with laws and regulations, the POTW option
rates higher in terms of effectiveness because of the reliability of the POTWs and because it is more easily
implemented.
Public Comments Overview
The sections that follow provide brief responses to some of the main issues raised in the public comments
received on the Second ESD. The issues have been organized into the following five categories:
Q Human Health, Environmental, and Biosolids Concerns
Q Sewer Leakage Concerns
Q Radiation Topics
Q Costs - Comparison of Alternative 1 and Modified Alternative 2B
Q Former Tire Pile Area (FTPA) Issues
Human Health, Environmental, and Biosolids Concerns
A number of commenters expressed concern that the pretreated ground water from the Lowry Site would
contaminate the eastern Colorado environment and threaten the health of future generations by
contaminating the biosolids produced at Metro's POTW.
Metro's biosolids will not be adversely affected
as a result of treating Lowry Site ground water at
Metro's POTW.
Sending pretreated Lowry Site ground water to
the Metro wastewater treatment plant will not
contaminate the air, water or land in eastern
Colorado. The biosolids produced by Metro will
continue to meet all regulatory requirements and
will not pose a threat to human health or the
environment. Metro's biosolids will not be adversely affected as a result of treating Lowry Site ground
water at Metro's POTW.
The Lowry Site ground water will be treated onsite to comply with pretreatment limits set to protect human
health and the environment (for both organic and inorganic contaminants) and specified in a wastewater
treatment permit to be issued by Metro. The pretreated ground water will be discharged to Metro's POTW
in accordance with the National Pretreatment Program, pursuant to the Clean Water Act.
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Permit requirements protect water discharge
quality, biosolids quality, and community and
workers' health and safety.
Industrial discharges to Metro are allowed, with pretreatment, under the Federal Clean Water Act and
regulations developed under the Colorado Water Quality Control Act The requirements under these
regulations are designed to ensure that Metro maintains the quality of its discharge and the biosolids it
produces. All discharges to surface water in the State of Colorado are regulated under the Colorado
Discharge Permit System (CDPS) Regulations. CDPS discharge limits for Metro's effluent are designed to
protect fish, other aquatic and vegetative life, and downstream uses of the South Platte River.
The National Pretreatment Program regulates industrial waste discharges to municipal sewer systems and is
applicable to every large wastewater treatment plant and many small wastewater treatment plants in the
United States. In Colorado, the National Pretreatment Program is implemented by EPA and is the program
under which Metro will issue a discharge permit to
the Respondents to the RD/RA Order. This permit
will control the quality of the pretreated ground
water to be discharged to the sewer system, and
will require that the pretreated ground-water
quality be monitored before the water is
discharged to the sewer system. Permit
requirements protect water discharge quality and
biosolids quality, as well as community and worker health and safety. The addition of pretreated Lowry
Site ground water to the wastewater stream to be treated by Metro will have no measurable effect on the
quality of Metro's discharge to the South Platte River.
"Sludge" is the solid that settles and is removed when a liquid with suspended solids passes through a
settling tank. Sludge includes 80 to 90 percent water. The remaining percentage (10 to 20 percent) is a
mixture of organic and inorganic solids and dissolved substances. Sludge contains nutrients such as
nitrogen and phosphorus, and pathogens such as viruses and parasites. Sludge also contains cells from
microorganisms that are used to treat the wastewater, organic chemicals, and inorganic chemicals (such as
iron or salts). Sludge is treated before disposal. This treatment is designed to remove water, reduce the
level of pathogens, stabilize volatile solids, and make the sludge less attractive to rodents, insects, and
other animals. After sludge is treated, it is referred to as biosolids.
Biosolids are produced in the United States at a rate of 6,856,169 dry tons per year. Of those solids,
55 percent are land-applied. In Colorado, 78 percent of the 60,273 dry tons of biosolids generated each
year are land-applied. Land application rates in other states range from 0 percent (Alaska) to 100 percent
(Delaware, North Dakota, and Oregon). Table ES-1 shows the quantity of biosolids generated and their
disposal mechanisms in the United States.
Over the past 20 years, biosolids management practices have changed significantly, moving from disposal
toward more beneficial use. Beneficial use of biosolids, such as land application, is continuing to rise. In
a recent poll by a trade industry magazine, 30 states indicated that beneficial use rates are expected to
increase and more biosolids will be land-applied in the future.
In Colorado, land application of biosolids is regulated under the State ct Colorado Biosolids Regulation
and the Federal Part 503 Regulations. These regulations contain requirements and standards that have
been established to protect human health and the environment. Based on 20+ years of research and
analysis, the regulatory limits for land-applied biosolids have been established to be protective of public
health and the environment.
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Table ES-1. Biosolids Management in the United States
EPA Region and States
Region 1 - Maine, Vermont, New Hampshire,
Massachusetts, Connecticut, Rhode Island
Region 2 - New York, New Jersey
[legion 3 - Pennsylvania, Maryland, Delaware,
West Virginia, Virginia
Region 4 - Kentucky, Tennessee, North Carolina,
South Carolina, Georgia, Alabama, Mississippi,
Florida
Region V - Minnesota, Wisconsin, Michigan,
Ohio, Indiana, Illinois
Region 6 - New Mexico, Texas, Oklahoma,
Arkansas, Louisiana
Region 7 - Nebraska, Kansas, Iowa, Missouri
Region 8 - Montana, North Dakota, South
Dakota, Wyoming, Utah, Colorado
Region 9 - California, Nevada, Arizona, Hawaii
Region 10 - Alaska, Washington, Oregon, Idaho
TOTAL
Total solids
(dry
tons/year)
367,430
605,046
1,040,206
1,050,326
1,705,316 .
425,203
511,712
111,880
819,050
220,000
6,856,169
Land
Application
24%
30%
74%
57%
51%
53%
65.5%
68%
51%
89%
55%
Surface
Disposal
46%
14%
16%
30%
2%
45%
4%
29%
36%
2%
19%
Incineration
30%
23%
10%
12%
30%
2%
25.5%
0%
4%
9%
17%
Other
0%
33%.
1%
1%
17%
0%
5%
3%
7%
0%
9%
Source: Bastion, Robert K. 1997. "Biosolids Management in the United States, A State-of-the-Nation Overview. "
Water Environment & Technology. Vol. 9, No. 5, Pp. 45-50.
Metro's biosolids may be applied beneficially to
land anywhere, even home gardens.
Metro's biosolids are not a hazardous waste.
The biosolids that are spread on Metro's land near
Deer Trail, Colorado are classified under Federal
and state regulations as "exceptional quality."
This means that the concentrations of pollutants
remaining in the biosolids are so low that the
biosolids can be applied beneficially to land
anywhere, even home gardens, and the biosolids
are regulated as a fertilizer. Metro's biosoHds are not a hazardous waste.
Table ES-2 provides data on the concentrations of chemicals that are allowed for biosolids to be classified
as "exceptional quality " under Federal and state regulations, the concentrations currently found in the
Metro biosolids, the maximum allowable concentrations (based on Metro's pretreatment standards) that
would be accepted from the Lowry Site, and the combined concentrations. Data in the table show that the
addition of the pretreated ground water from the Lowry Site will not affect the "exceptional quality " status
of the biosolids generated by Metro.
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Table ES-2. Exceptional Quality
Parameter
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
Gross Alpha, pCi/g
Gross Beta, pCi/g
"Exceptional
Quality" Biosolids
(Mg/g)
41
39
1200
1500
300
17
N/A
420
100
2800
N/A
N/A
Current
Metro Levels
(ug/g)
1.7
6
66
519
78
2.2
19
31
3.1
684
20
23
Biosolids
Maximum
Levels from
Lowry" (ug/g)
0.3
2
3
5
1
0.1
1
3
0.2
10
0.03
0.04
Metro & Maximum
Lowry Levels
Combined (ug/g)
2.0
8
69
524
79
2.3
20
34
3.3
694
20
23
Mg/g - micrograms per gram
pCi/g - picocuries per gram
N/A - not available
' contribution to Metro's biosolids if the Lowry Site were to discharge at the maximum allowable concentration
Source: Metro Wastewater Reclamation District. 1997. Preliminary Proposed Self-Monitoring Requirements and
Pollutants to be Limited by Permit for the Lowry Superfund Site Discharge to the dry of Aurora and the Metro
District.
Nevertheless, in response to community concerns, Metro will expand its environmental monitoring and
community involvement activities in eastern Colorado. Metro has already begun working with the Deer
Trail (Arapahoe County) and Agate (Elbert County) Soil Conservation Districts (SCDs) to develop
comprehensive soil conservation practices for Metro's Deer Trail property.
In response to community concerns, Metro will
expand its environmental monitoring and
community involvement activities in eastern
Colorado.
In addition to working with the SCDs, Metro is
also working directly with the Natural Resources
Conservation Service (NRCS) in developing a soil
conservation program. In addition, Metro intends
to fund a monitoring program that will enable
independent verification of Metro's biosolids -
quality and the impacts of Metro's biosolids land
application activities on soils, surface water, and ground water in Arapahoe and Elbert Counties. It is
envisioned that Arapahoe and Elbert Counties will be the agencies in charge of this monitoring program.
Metro, in consultation with EPA and CDPHE, intends to undertake additional community involvement and
monitoring activities including: working closely with community working groups or citizens' monitoring
committees; incorporating community concerns and suggestions into the sampling and monitoring
programs (currently under development); implementing a sampling and analysis program to establish
"baseline" data for relevant areas in eastern Colorado; sending monitoring reports or other information to
local libraries; arranging tours of the Metro facility and the biosolids application areas; developing and
DEN7H/DAAVORDPWIN/095.WPD
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conducting workshops on biosolids, the pretreatment program, other environmental issues near Metro's
Deer Trail property, etc.; developing outreach materials (e.g., fact sheets) on appropriate topics; and
implementing recommendations from the report entitled, Field Study of Institutions, Attitudes and
Opinions Impacting Acceptance of Biosolids Land Application Programs in Northeastern Colorado
(February 1994).
Sewer Leakage Concerns
Several commenters expressed the concern that the sewer pipes transporting pretreated Lowry ground
water may leak or back up, causing contamination to be spread.
The presence of pretreated Lowry ground water
in the wastewater stream within the sewer
systems will pose no additional risk to the
public, the environment or sewer workers.
Pretreated Lowry Site ground water will be
transported through sewer lines to the POTWs.
Although it would be unrealistic to assume that
sewer lines never break or leak, the presence of
pretreated Lowry Site ground water in the
wastewater stream within the sewer systems will
pose no additional risk to the public, the
environment, or sewer workers. First, concentrations of contaminants in the pretreated Lowry Site ground
water will meet Metro's and Aurora's pretreatment standards. Second, these pretreatment standards for
nonhousehold discharges are more protective of the environment than are the standards for raw household
sewage discharges.
Radiation Topics
The following general discussion provides
introductory information on several topics
related to radiation.
The discussion is intended to supplement
specific responses related to radiation questions
in Volume I of the Responsiveness Summary,
and to provide the reader with some fundamental
concepts that underlie all of the responses
relating to radiation and radiation exposure.
Many of the commenters expressed concern that
the Lowry Site water may contain plutonhtm and
other radionuclides.
Radiation is the energy released when a
radioactive substance disintegrates. This process
of energy release through disintegration is referred
to as radioactive decay. The higher the number
of disintegrations or decays during a given time
period, the greater the radioactivity of the
material.
During radioactive decay, energy is given off by
the release of atomic particles (e.g., alpha or beta particles), through emission of electromagnetic energy
(gamma or x-rays), or through release of both particle and electromagnetic energy. It is the energy released
by radioactive materials that can cause potential health effects in humans through direct damage to
sensitive biological tissues and cells.
DEN/H/DAAVORDPWIN/09.VWPD
10
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The amount of radioactivity in a sample or
substance is expressed in units of Curies (or
fractions of a Curie). Most environmental
radioactivity measurements are expressed in
picocuries (pCi) . A picocurie contains one
trillionth of the radioactivity in a Curie, and
represents approximately two disintegrations per
minute of a radioactive substance. Typically, the
concentration of radioactivity in a soil or water
Radioactivity is naturally present in soil in
concentrations ranging from a few pCi/g to tens
of pCi/g. Radioactivity also occurs naturally in
water with concentrations ranging from a few
pCi/L to tens of pCi/L for some radionuclides
(like radium and uranium) and from a few to
thousands of pCi/L for radon.
sample is measured in units of pCi per gram
(pCi/g) or pCi per liter (pCi/L). Radioactivity is present in soil naturally in concentrations ranging from a
few pCi/g to tens of pCi/g. Radioactivity also occurs naturally in water with concentrations ranging from a
few pCi/L to tens of pCi/L for some radionuclides (like radium and uranium) and from a few pCi/L to
thousands of pCi/L for radon. Table ES-3a provides a summary of typical background levels for some
naturally occurring radionuclides in rocks and soil, and Table ES-3b provides a similar summary for water.
The amount of radioactivity in an environmental sample (soil or water) is measured through detection of
the alpha and beta particles, or gamma energy released from the sample. Understanding how these
particles and energy interact is important to interpreting and understanding the results from radioactive
sample analyses. The simplest type of radioactive analysis is measurement of the gamma radiation
released from a sample. The amount of gamma radiation can be used directly (often with minimal sample
preparation) to determine the total activity in the sample. Because gamma radiation travels more than
several feet in air, and is not easily absorbed or shielded, gamma-emitting radionuclides usually are easily
detected and measured with low analytical uncertainty.
Table ES-3a. Concentrations of Naturally Occurring Radioisotopes in Rock and Soil (pCi/g)
Type of Rock or Soil
Igneous rocks
Basalt (crustal average)
Granite(cnista) average)
Sedimentary rocks
Shale sandstones
Beach sands (unconsolidated)
Carbonate rocks
Continental upper crust Average
Soils1
Soil"
Potassium-40
8
>30
22
<8
2
l
23
11
3-19 .
Rubidium-87
0.8
4-5
3
< 1
0.2
3
1
3.5
Thorium-232
0.3-0.4
1.5
1.4
0.7
0.2
1.2
1.0
0.2-1.4
Uranium- 238
0.2-0.3
1.1
1.1
1.1
0.7
1.0
1.8
0.2-1.4
"In-situ gamma spectral measurements at 200 locations by Lowder, W.M., et al. 1964. "Field Spectrometric
Investigations of Envrionmental Radiation in the U.S.A." The Natural Radiation Environment. J.S. Adams and
W.M. Lowder, ed., University of Chicago Press, Chicago, Illinois.
bPotassium, thorium, and uranium from, United Nations Scientific Committee on the Effects of Atomic Radiation.
1982. Ionizing Radiation: Sources and Biological Effects. Report to the General Assembly. Annex 1, UN82;
National Council on Radiation Protection and Measurements (NCRP). 1976. Environmental Radiation in the
United States. NCRP Report No. 50. December 27.
Source: EPA. 1990. Guidance for Data Usability in Risk Assessment. Interim Final. EPA/540/G-90/008.
Directive: 9285.7-05. Office of Emergency and Remedial Response, Washington, DC. October.
DEN/H/DAAVOROPWIN/095.WPD
11
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Table ES-3b. Concentrations of Naturally Occurring Radioisotopes in Ground Water (pCi/L)
Average1
Median1
Regional Data2
Radium-226
0.87
0.4
0.133-28.5
Radium-228
2.0
1.5
NA
Total Uranium
NA
0.1-20
0.264-18.83
Radon
881
289
NA
'Taken from the background information supporting proposed rulemaking for drinking water regulations for
radionuclides (Federal Register, National Primary Drinking Water Standards: Radionuclides. Notice of Proposed
Rulemaking. Volume 56, No. 138, Thursday, July 18, 1991)
2Taken from HLA. 1992. Final Remediation Investigation Report for the Shallow Groundwater and Subsurface
Liquids and Deep Ground Water Operable Units, Lowry Landfill, Arapahoe County, Colorado, March 25.
3Regional information for uranium reported as Uranium-238
NA - Data not available
Beta particles generally travel a few inches to a few feet in air (depending on their energy), and can be
absorbed or shielded by a few inches of plastic (again depending on the energy of the beta particle).
Measurement of beta-particle emitting radionuclides typically requires some sample preparation to extract
the radionuclide onto a thin layer so that the beta particles can be detected. This sample preparation
introduces some uncertainty or error into the final result.
Radioactive materials that decay primarily by alpha particle emission (such as most types of plutonium) are
the most difficult to measure because alpha particles only travel a short distance in air (an inch or less), and
can be completely stopped by something as thin as a sheet of paper. The analysis process for alpha
emitters typically includes a series of chemical extraction steps, with a final sample consisting of a very
thin layer of material plated on a small disk. Any interferences (such as moisture or dust on the final
sample disk) can cause significant errors or uncertainties in the final sample result.
Radioactive sample results typically are displayed as the sample concentration (in pCi/g or pCi/L), with an
associated minimum detectable activity (MDA) level, and counting errors. A separate MDA or
detection level usually is calculated for every sample result. This value represents the level that can be
detected with a high degree of confidence (i.e., with a small probability of either false positive or false
negative results). The counting error accounts for some of the uncertainty in a sample result caused by the
statistical nature of radioactive decay. It does not include consideration of errors or uncertainties
associated with the sampling event itself. This counting error term is a useful tool in determining how
representative a sample result is. It is an indication of the range of radioactivity that could actually be
present in the sample, given the possible errors associated with the counting process.
While the concentration of radioactivity (e.g., pCi/g) is important, the concentration alone actually says
very little about the potential hazard associated with the soil and water containing the radioactivity. The
absorbed dose is a quantity that provides an indication of the potential health effect or hazard associated
with the radioactivity. The absorbed dose is expressed in rads (radiation adsorbed dose), and is a measure
of the amount of energy deposited by radiation in an organ or tissue of interest. Absorbed dose (rads) is
the quantity that is often used for studies that focus on a particular organ. An example is the recently
released study on fallout from past atmospheric atomic weapons testing that focused on doses of iodine-
131 to the thyroid gland in exposed individuals.
DEN/H/UAAVORDP\V1N/095.WPO
12
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A more useful quantity for expressing potential human health impacts is effective dose equivalent.
Effective dose equivalent is similar to adsorbed dose except that it includes consideration of the differences
in biological effectiveness of different types of radiation and also considers the relative risks of cancer for
different organs. Effective dose equivalent is measured in a unit called rem (radiation equivalent man).
As a point of reference, the International Commission on Radiological Protection (ICRP) and the National
Council on Radiation Protection and Measurements (NCRP) have established recommended limits on
radiation exposure for the general public. These consensus scientific groups have recommended that
public exposures from all sources except medical exposures and radon be limited to 100 millirem per year
(mrem/yr). They further recommend that doses be minimized through use of the concept of as low as
reasonably achievable (ALARA), and that the dose from any single site should be limited to a fraction of
the 100 mrem/yr total limit.
Current proposed guidance from EPA (EPA. 1994. Federal Radiation Protection Guidance for Exposure
of the General Public. Federal Register. Vol. 59, No. 246, December 23.), and Department of Energy
(DOE) (10 CFR Part 834), (DOE. 1993. Radiation Protection for the Public and the Environment. Notice
of proposed rulemaking and public hearing. Federal Register. Vol. 58, No. 56, March 25), and recently
finalized rulemaking by the Nuclear Regulatory Commission (NRC) (NRC. 1997. Radiological Criteria
for License Termination; Final Rule. Federal Register. Vol. 62, No. 139, July 21.) comply with the
recommendation of the ICRP and NCRP by establishing a radiation exposure limit for the general public
of 100 mrem/yr from all sources (except medical and radon), and stating that the dose from any single site
should be a fraction of the 100 mrem/yr total limit. Recently, the NRC finalized its decommissioning
rulemaking efforts, and established 25 mrem/yr as the dose limit for exposure of the public to a single
decommissioned site. These regulations also require that doses be reduced to as far below the legal limit as
is reasonably achievable, taking costs and benefits into account. This philosophy of ALARA usually
results in further reduction of potential dose to a level on the order of a few mrem per year.
The regulations and guidance discussed previously have been developed to limit public radiation exposures
to safe levels. The major health concern for limiting radiation exposures is limiting the possibility of
cancer by such exposures to a negligible level. EPA requires that the risk associated with CERCLA sites
be limited to a range of 10"6 to 10'4. This risk range usually is interpreted as being between one cancer in a
population of one million persons to a few cancers in a population of 10,000 persons. The dose limits
discussed previously (in practice usually less than 25 mrem/yr) provide assurance that the possibility of
cancer is acceptably low, particularly considering that background radiation exposures are typically several
times higher than actual public exposures from a man-made source. Limiting public radiation doses to less
than 25 mrem/yr generally will provide adequate assurance that the CERCLA risk criteria have been met.
The sources of the radiation that have been detected in the Lowry Site samples are most likely the same as
the sources of the background radiation that can be detected in the general environment. Radiation occurs
naturally in the environment, and activities such as the past atmospheric nuclear weapons tests have
contributed to the background levels of radiation. The primary sources of background radiation that could
impact the Lowry Site samples are:
Q Cosmic radiation, which is radiation from space;
U Terrestrial sources of radiation including rocks and soil that naturally contain radioactive minerals; and
CJ Radioactive fallout from past atmospheric nuclear weapons testing.
UEN7H/DAAVORDPWIN/095.WPD 13
-------
Cosmic radiation contributes quantities of radionuclides such as tritium and carbon-14. These
radionuclides are present in soil and water, and may have contributed to the detection of radionuclides at
the Lowry Site. For example, tritium is present in the ambient environment both naturally, from cosmic
radiation, and artificially, from past atmospheric nuclear weapons testing. Tritium can be an interference
in the analytical procedure for plutonium-241. It is possible that natural background levels of tritium could
have contributed to the positive detections of plutonium-241 at the Lowry Site.
Detectable levels of plutonium have been
measured in ground water from background
samples in the Denver metropolitan area.
While it is possible to detect plutonium in
ground water and soils from background areas,
this does not mean that there is a potential health
threat associated with such low-level detections.
Naturally occurring radionuclides such as
uranium, thorium, and radium are present in
rocks and soil in varying quantities throughout
the world. In the Denver area, these
radionuclides are present in soil in higher
concentrations than in most areas of the United
States because of the geology of the Rocky
Mountain area. These radionuclides contribute
to the overall radioactivity in any soil or water
sample from the Lowry Site, and could
contribute interferences that increase the overall
error in more difficult measurements such as plutonium and americium. As an example, the naturally
occurring radium-224 isotope sometimes is mis-identified as americium-241 because it emits an alpha
particle that has nearly the same energy as the americium alpha particle.
Past atmospheric testing of nuclear weapons has caused detectable amounts of man-made radionuclides
such as plutonium, americium, and tritium to be dispersed in variable amounts around the world. These
radionuclides are detectable in trace quantities in soil and other media, and this source may be a contributor
to the sporadic detections of plutonium and americium that have been seen in Lowry Site samples.
Detectable levels of plutonium have been measured in ground water from background samples in the
metropolitan Denver area. While it is possible to detect plutonium in ground water and soils from
background areas, this does not mean that there is a potential health threat associated with such low-level
detections. There are measurable quantities of chemicals and radionuclides other than plutonium in
ground water in the Denver area, and in all other ground-water systems in the United States.
EPA has established standards for drinking water that
limit the concentrations of chemical and radiological
contaminants to levels that are judged to be safe for
human consumption. These are called maximum
contaminant levels or MCLs. For radionuclides, EPA
has established a performance standard of 15 pCi/L for
alpha-emitting radionuclides (excluding uranium and
radon).
Ground water leaving the Lowry Site must meet
ROD performance standards or pretreatment
standards for radionuclides before the water can
be sent to the Metro and Aurora wastewater
treatment plants.
Costs - Comparison of Alternative 1 and Modified Alternative 2B
Several of the commenters questioned the cost of the sitewide remedy and the two alternatives for ground-
water treatment. The commenters expressed concern that the POTW option was selected primarily
because it is the less costly option.
DEN/H/DAAVORDPWIN/09.XWPD 14
-------
As part of the process for evaluating the I _., " ! '. ~ " "
alternatives identified in the ESD, the estimated lle *? " *"*»* showe? a'°St
capital costs and operation and maintenance differential between onsite and offsite treatment,
/r\o+M\ _* r.u i. ^ cost was only one of the catena used to evaluate
(O&M) costs of the two alternatives were . , " . _,. . » i r
, . . , . ,. . ... __. the two alternatives. EPA uses a total of nine
calculated and compared in accordance with EPA . , . r c , ~T^
.. T.I f . u cntena to evaluate the ments of Superfund
guidance. Total net present worth costs were ,.
estimated by adding capital costs to the net present
worth of the annual O&M costs for a 30-year ^^^^^^^^^^^^^^^^^^^^^^^
period, using an interest rate of 5 percent. The
total net present worth cost for Alternative 1 (POTW option) is estimated to be $6,354,000. This includes
capital costs for a lift station, piping, excavation, and construction; the sewer connection fees; design and
construction management costs; O&M costs including equipment repair costs; POTW treatment fees; and
water augmentation costs.
The total net present worth cost for Modified Alternative 2B is estimated to be $9,300,000. This includes
capital costs for the reverse osmosis system, an iron removal system and an evaporation system; design and
construction management costs; O&M costs; and water augmentation costs.
Long-term monitoring is included for both options and is projected to cost approximately the same for both
options.
While the cost analysis showed a cost differential between onsite and offsite treatment, cost was only one
of the criteria used to evaluate the two alternatives. EPA uses the nine NCP criteria to evaluate the merits
of Superfund remedies. The first two criteria are: 1) overall protection of human health and the
environment; and 2) compliance with applicable or relevant and appropriate requirements (ARARs) of
other Federal and state environmental statutes. If a remedial alternative does not meet the first two criteria,
it is not carried over for further analysis. If an alternative does fulfill the first two criteria, it is then
reviewed against five more criteria: 3) long-term effectiveness and permanence; 4) reduction of toxicity,
mobility, or volume through treatment; 5) short-term effectiveness; 6) implementability; and 7) cost,
including capital and O&M cost. The final two criteria, 8) State acceptance and 9) community acceptance,
are evaluated following public comment.
EPA and CDPHE compared the two alternatives according to these criteria and concluded that the POTW
option would achieve the best balance among the criteria. The agencies have determined that this
alternative is the most technically feasible, cost-efficient, protective, and reliable option. The agencies
have further determined that this alternative would achieve better long-term effectiveness, provide a more
significant reduction in toxicity, mobility, and volume through treatment, be more cost effective, and be
protective of human health and the environment.
The Lowry ROD indicates that the 30-year net present worth estimate, including capital and annual O&M
costs, for the sitewide remedy is $93,848,000. EPA's costs to date (including contractor costs) are
approximately $27 million. It is estimated that the Potentially Responsible Parties have spent between $40
million and $70 million on remedial costs (including costs reimbursed to EPA).
DEN/H/DA/WOROPWIN/095.WPD 15
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Former Tire Pile Area (FTPA) Issues
EPA received only a few comments on this element of the Second ESD. The comments focused on
technical aspects of the design, most of which will be evaluated during preparation of the FTPA remedial
design.
The March 10, 1994 Lowry Site ROD specified that "contaminated materials in the former tire pile area
shall be excavated and characterized for offsite treatment and disposal." The ROD specified that "it is
anticipated that the solids and soils shall be treated using stabilization before disposal, but actual treatment
methods shall be determined by EPA, in consultation with CDPHE, during RD."
Because the ROD does not specifically identify a treatment technology, treatability studies and an
evaluation of potential treatment options were performed by the Respondents to the RD/RA Order. The
Respondents' report is entitled Treaiability Test Summary Report, Former Tire Pile Area Waste Pits
(Parsons ES, February 19, 1997). In this evaluation, the Respondents evaluated two possible remedial
designs:
Q Physical drying/controlled aeration
Q Enhanced bioremediation
Treatability test results indicated that enhanced bioremediation would not meet the remedial, or cleanup,
objectives established by EPA and CDPHE. Results of the physical drying/controlled aeration tests
indicated that this process would meet the remedial objectives. Physical drying/controlled aeration will
include the following elements.
Q Excavating, handling, and staging of FTPA waste pit materials
Q Treating FTPA waste pit materials
Q Backfilling the material or disposing in an onsite disposal area
The Second ESD identified a change to the FTPA treatment and disposal to include onsite treatment and
disposal instead of offsite treatment and disposal.
i
Locations of the Responsiveness Summary
Because of its size (several hundred pages) and in an effort to conserve paper, only the Executive
Summary of the Responsiveness Summary was mailed to each commenter.
If you are interested in reviewing or copying (all or part of) the complete, multi-volume Responsiveness
Summary, you can do so at any of the following locations:
EPA Superfund Records Center Aurora Public Library
999 18th Street 14949 East Alameda Drive
5th floor, North Terrace Aurora, CO 80012
Denver, CO 80202 303/739-6600
303/312-6473
DEN/H/DAAVORDPWIN/095.WPD 16
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Bennett Public Library
495 Seventh Street
Bennett, CO 80102
303/644-3303
Deer Trail Public Library
350 Second Avenue
Deer Trail, CO 80105
303/769-4310
Contacts
If you would like to talk with someone about the Responsiveness Summary or other issues related to the
Lowry Landfill Superfund Site, please feel free to contact any of the following people:
Byers Public Library
404 East Front Street
Byers, CO 80103
303/822-9392
Strasburg Public Library
Mobile Unit on Strasburg School Lot
303/622-4268
U.S. Environmental Protection Agency
Marc Herman
EPA Project Manager
1-800-227-8917 ext. 6724 or
303/312-6724
herman.marc@epamail.epa.gov
Diana Hammer
Community Involvement Coordinator
1-800-227-8917 ext. 6601 or
303/312-6601
hammer.diana@epamail.epa.gov
Colorado Department of Public
Health and Environment
Joe Vranka
State Project Officer
303/692-3402
joe.vranka@state.co.us
Marion Galant
Community Relations Manager
303/692-3304
marion.galant@state.co.us
DEN7H/D.VWORDPWIN/095.WPD
17
-------
Comment Letters Index
DENDividrs2.doc/l
-------
Comment Letters Index
Name
Moe
Rayma
Laura
Bill R.
Ilene D.
^eona R.
Adrienne
Beverly
Ken
Pat
B. Jordan
Fean
LeRoy O.
Cindy
Vlanan B.
Kathryn
Deborah M.
Janet
Mindi Leigh
James
Lynne
CleoM.
Colleen A.
Richard A.
Dennis D.
Harold
Doug
Evonne
B.
Geraldme M.
Lucinda
B.
Ruth E.
Jessica
Mike
George
Rosie
Pamela
Daniel L.
Paul W.
Jaime
Albert
Albert
Alexander
Allison
Allison
Allison
Anderson
Anderson
Armstrong
Armstrong
Asnicar
Bain
Bank
Barr
Beach
Beer
Behrens
Bergdorfer
Berry
Bilisoly
Bilisoly
Blakney
Boland
Boland
Bollmann
Bolstad
Bongiomi
Bongiomi
Bonlee
Bowman
Boyd
Boyett
Boyett
Brannan
Braudrick
Brawlv
Breeden
Brosel
Brotzman
Brown
Burchfield
Volume/Page No.
of Comment
117121
11/388
11/122
11/123
11/124
11/125
11/509
11/617
11/126
11/127
11/511
11/487
IU647
11/128
11/129,617
11/141
11/130
11/234
11/264
11/131
11/132
11/389
11/133
11/133
11/637
11/390
11/391
11/392
11/134
11/135
11/567
11/136
11/136
11/137
11/138
H/139
11/140
11/141
11/512
11/142
11/393
Volume/Page No.
of Response
1/69
1/72
1/69
1/69
1/69
1/69
1/75
1/129
1/69
1/69
1/79
1/74
1/148
1/69
1/69, 129
1/69
1/69
U69
1/69
1/69
1/69
1/72
1/69
1/69
1/146
1/72
1/72
1/72
1/69
1/69
1/89
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/80
1/69
1/72
-------
Comment Letters Index
Name
Mark R.
lonald E.
Ruby A.
Jnda
Donn L.
L. T. L. (Lin)
Mike
Stephen
Susanne G.
Bob
Kathy
Caryl
lamona
Wil
David
Valrie
Richard B.
DanaD.
Leonard W.
Harry
Nancy L.
(Illegible)
Brandy
Debbie
Thomas A.
Virginia
tfarvey
Galen
Olive
W.
Ken
Anne
James
Dave
Craig
Wendy
Marilyn R.
Edward
Tammy Sue
Michael O.
Walter L.
Burchfield
Burchfield
Burchfield
Cacek
Calkins
Callow
Card
Card
Card
Carlson
Carter
Cat
Chase
Chase
Clark
Clark
Clay
Clay
Cole
Collins
Collins
Coolidge
Cowell
Cowell
Cox
Cox
Crandell
Crawford
Crawford
Crawford
Prawford
Culver
Currier
Dannar
Darnell
Darnell
Davies
Davis
Davis
Dean
Dinwiddie
Volume/Page No.
of Comment
11/394
11/395
11/396
11/143
11/515
11/503
11/144
11/397
11/144, 398
11/618,645
11/145
11/146
11/147
11/517
11/148
11/148
11/149
11/399
11/488
11/150
11/151
11/141
11/152
11/153
11/154
11/400
11/483,617
11/155
11/156
11/157
11/401
11/518
11/402
11/158
11/159
11/159
11/403
11/404
11/405
11/325
11/647
Volume/Page No.
of Response
1/72
1/72
1/72
1/69
1/80
1/74
1/69
1/72
1/69, 72
1/129, 147
1/69
1/69
1/69
1/81
1/69
1/69
1/69
1/72
1/74
1/69
1/69
1/69
1/69
1/69
1/69
1/72
1/73, 129
1/69
1/69
1/69
1/72
1/81
1/72
1/69
1/69
1/69
1/72
1/72
1/72
1/69
1/148
19
-------
Comment Letters Index
Name
R.
Charles
Donna
Edie
Jim
Judith
Mike
Saundra
Jane
Frank
Patty
Joseph J.
JohnD.
Elmer
Edwin O.
Clarence G.
Susan
Don
Sharon R.
K. M.
Marge
Justina L.
Patricia
LoriL.
Terry D.
Ivy
Donna
Winifred
D.
Jerry J.
Patricia R.
Daniel
Deborah K.
Dean
Sharon
Del Loyd
Diane
AlanJ.
Clarine
Donald E.
Marian
Dobey
Dorrance
Dorrance
Dorrance
Dorrance
Dorrance
Dorrance
Dorrance
Dough
Doyle
Doyle
Drexler
Drummond
Dudden
Edlund
Eldringhoff
Eldringhoff
Erickson
Estell
Falino
Falino
Falls
Fanner
Fischer
Fischer
Fischer
Fletcher
Forbes
Francis
Francis
Froman
Galanaugh
Gardner
Gaudat
Gaudot
George
Gilbert
Gilbert
Glass
Grahlmann
Granlmann
Volume/Page No.
of Comment
11/160
11/161
11/162
11/163
11/164
11/165
11/166
11/167
11/168
11/519
0/519, 617
11/520
11/169
11/563
11/647
H/170
H/171
11/175
11/564
11/234
11/234
II/234
11/565
11/172
11/173
11/406
11/174
11/175
11/176
11/177
11/178,617
11/489
11/179, 180
11/607
11/181
11/182
11/183
11/502
11/407
11/184
11/185
Volume/Page No.
of Response
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/82
1/82, 129
1/82
1/69
1/87
1/148
1/69
1/69
1/69
1/87
y69
1/69
1/69
1/88
1/69
1/69
1/72
U69
1/69
1/69
1/69
1/69, 129
1/74
1/69
1/123
1/69
1/69
1/69
1/74
1/72
1/69
1/69
20
-------
Comment Letters Index
Name
Kathv
Debby
William A.
lay
Shirley
Stacey John
:mmy
Tammy
Pearl A.
Frank C.
Sheryl E.
Elmer
arnes
Jennis H.
Gerald A.
Amber
Conine K.
Elmer
Darlene
Thomas W.
Carolyn
Jerry
Dr. John W.
Clara M.
Harold E.
Harry
Leslie
Peter
John
M.A.
Viargaret
Albert K.
Margaret F.
Neil
Angela
Eric
Jack
Larry
Fred
Wanda
Richard S.
Griffin
Grindel
Groves, Jr.
Gunter
Gunter
Gust
Gustafson
Guy
Hageman
Hahn
Hahn
Hall
Hall
Hall
Hall
Hambek
Hamrnel
Hanes
Hanket
Hanket
Hankins
Hankins
Hanks
Hanks
Hanks
Hanks
Hanks
Hanks
Hanks
Hanks
Hanks
Hanlon
Hanlon
Hansen
Hairt
Hart
Hawkins
Heath
Hendrickson
Hetfield
Hillier
Volume/Page No.
of Comment
11/186
11/121
11/490
11/408
11/409
11/187
11/188
11/189
11/617
11/190
11/191
11/192
11/193
II/157, 410
H/411
11/194
11/195
11/196
11/412
11/413
11/197
11/198
11/199
11/200, 484
11/200, 484
11/566
11/201, 567
11/202
11/414
11/568, 645
11/414
11/415
11/416
11/491
IV203
11/417
11/573
11/204
II/492
11/205, 617
II/580, 586
Volume/Page No.
of Response
1769
1/69
1/74
1/72
1/72
1/69
1/69
1/69
1/129
1/129
1/69
1/69
1/69
1/69, 72
1/72
1/69
1/69
1/69
1/72
1/72
1/69
1/69
1/69
1/69, 73
1/69, 73
1/88
1/69, 89
1/69
1/72
1/89, 147
1/72
1/72
1/72
1/74
1/69
1/72
1/93
1/69
1/74
1/69, 129
1/97
21
-------
Comment Letters Index
Name
Bill
Robert W.
9
Mr. and Mrs. Forest
Gene
WardL.
Donald S.
Mr. & Mrs. Jerry
JayN.
Arden L.
JohnR.
Claudine
Rose
Bill
Linda
RheaR.
Hugh E.
Nancy L.
Patricia L.
Roselle
AlmedaM.
Christine
Michael
Nina
Hingeley
Kite
Hollingsworth
E. Hollingsworth
Hollingsworth
Hollingsworth
Holstrom
Hooker
Hutchison
Intermill
Jacus
Jeannenaud
Jennings
Johnson
Johnson
Johnson
Johnson
Johnson
Johnson
Johnson
Jones
Jones
Jones
Judd
Char K(?)
Craig
Donna Hall
J.
Bobbi S.
Florene K.
Paul
Marvlin
Carol
Steven A.
Daniel L.
Glenn
Sandra S.
Norma J.
M.
Michele
Allen
Keel
Keel
Keenan
Keenan
Kershman
Kettering
Kitchen
Kitzman
Knutson
Koephe
Koephe
Koephe
Koephe
Konrath
Konrath
Konrath
Volume/Page No.
of Comment
II/418
11/598
11/207
11/206,419
11/208
11/381
11/596
11/209
11/504
11/210
11/602
11/211
11/421
11/212
11/213
11/214, 617
11/422, 423
11/424
11/425
11/493
11/215
11/216
11/217
11/604
11/208
11/218
11/219
11/220
IU426
IV221
11/222
11/223
11/303
11/427
11/224
11/225
11/226
11/428
11/228
11/227
11/605
Volume/Page No.
of Response
1/72
1/122
1/69
1/69, 72
1/69
1/69
1/121
1/69
1/74
1/69
1/122
1/69
1/72
1/69
1/69
1/69, 129
1/72
1/72
1/72
1/74
1/69
1/69
1/69
1/122
1/69
1/69
1/69
1/69
1/72
1/69
1/69
1/69
1/69
1/72
1/69
1/69
1/69
1/72
1/69
1/69
1/123
22
-------
Comment Letters Index
Name
Karen
Margaret E.
Mildred L.
Ken
Garry J.
Dolores
Carl
Amy
Trudy
William
Mary E.
Dale
Dolores
Kate
Ginger
Diane
Kent R.
Robert W.
Wm. A.
C(?) J.
Dana
VeraC.
Margaret M.
Doris
Harold W.
Kelly
Lonnie
BenJ.
Chris
Jeff
Joseph F.
Margie
Susan K.
Deanne
Jill
Douglas R.
Joan I.
Robert
DoLaras
Robert E.
Don
Konrath
Kontour
Kontour
Koslowski
Kramer
Kroh
Kroh
Kuhn
Lacey
Larson
Lasecke
Lauer
Lavoie
Lawrence
Lee
Lee
Lee
Legge
Lehman
Lehman
Lemme
Lessy
Lien
Lind
Lind
Lindner
Lindner
Linnebur
Linnebur
Linnebur
.Linnebur
Linnebur
Linnebur
Linnebur
Linnebur
Lippett
Lippett
Lippett
Lisco
Lisco
Lockwood
Volume/Page No.
of Comment
11/606
11/229
11/429
11/230
11/231
11/232
11/430
11/231
11/234
11/431
11/235
11/563
11/236
11/234
11/234
11/382
11/383
11/432, 608, 618
11/237
11/237
11/238
11/239
11/240
L 11/241
11/241
11/242
11/243
11/244, 433
11/245
11/246
11/247
11/248, 436
11/249, 437
11/434
11/435
11/250
H/25 1,438
11/438, 439
11/252
11/253
11/254
Volume/Page No.
of Response
1/123
1/69
1/72
1/69
1/69
1/69
1/72
1/69
1/69
1/72
1/69
1/87
1/69
1/69
1/69
1/69
1/70
1/72, 124, 129
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69, 72
1/69
1/69
1/69
1/69, 72
1/69, 72
1/72
1/72
1/69
1/69, 72
1/72
1/69
1/69
1/69
23
-------
Comment Letters Index
Name
Karen
Beverly
Robert L.
William M.
Gary P.
Carl
Donald F.
R. W.
Victoria
H. D.
Vtarjorie M.
Andrew C.
Gary
Nancy L.
Dr. John R.
Deborah K.
Erwin
Dawne Robin
Jeffrey L.
Jeffery Halley
Leola
Dawne M.
Dusty
Robert J.
Bob
Carl Ray
Theodore
Beverly Shaw
Joyce E.
Tina
Daniel
JohnJ.
Teresa
William
Donna
L. R.
D.
Cynthia L.
R.Max
K.
Paul
Lockwood
Lowell
Mall
Martin
May
Mayer.
McClary
McClelland
McCormack
McDonald
McLellan
McMinimee
Meier
Meier
Meinhold
Messer
Mettler
Myers
Meyer
Miller
Miller
Miller
Miller
Miller
Monde
Monde
Montgomery
Mooney
Mooney
Mooney
Mooney
Mooney
Morey
Morey
Morris
Morris
Mullins
Myers
Myers
Nelson
Nelson
Volume/Page No.
of Comment
11/254
11/255
11/494
11/647
11/440
11/495
11/609,611
11/505
11/256
11/563
11/496
11/513
11/257
11/258
11/613
11/256
11/259
11/260
11/261
11/262
11/263,617
11/441
11/442
11/615
11/234
11/264
11/443,616
11/265
11/266
11/267
11/268
11/269
11/270
11/271
11/272
11/273
11/274
11/275
11/444
11/276
11/277
Volume/Page No.
of Response
1/69
1/69
1/74
1/148
1/72
1/74
1/124, 125
1/74
1/69
1/87
1/74
1/80
1/69
1/69
1/127
1/69
1/69
1/69
1/69
1/69
1/69, 129
1/72
1/72
1/128
1/69
1/69
1/72, 129
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/72
1/69
1/69
24
-------
Comment Letters Index
Name
Cynthia
Kathy Jere
Dorothy P.
na
Bonnie
Vicki
V.
Betsy
John
toseph
Margaret
^amona
Claude D.
^ancy
Betty
Ness
Neu
Nickerson
Nordyke
Norris
Northcutt
O'Brien
O'Brien
O'Brien
O'Brien
O'Brien
O'Brien
Off
Overly
Owens
Gwendolyn A. P(?)
Alan
Constance
Arthur A.
Colleen
Floyd
Colleen
Lisa
David A.
George
Michael
Donna
Lisa
Vlelody
Shirley A.
Wilhelmina
Alice
Pamela L.
James R.
Shannon
Pam
Lylamae
Richard
Bonnie L.
JohnT.
Fred
Paine
Paine
Paine
Pakuer
Pakuer
Pakuer
Palm
Pampu
Pazell
Pearson
Peterson
Phillips
Pierce
Pisel
Plante
Porter
Post
Posten, II
Price
Price
Price
Price, Jr.
Rader
Rafferty
Raleigh
Volume/Page No.
of Comment
11/445
11/278
11/259
11/279
11/280
11/281
11/284
11/282
11/283
11/384
11/285
11/286
11/497
11/446
11/287
11/618
11/447
11/447,617
11/617
11/288
11/289, 448
11/448
11/290
11/619
IU291
11/292
11/293
11/294
11/449
11/295, 485
11/296
11/297
11/450
11/298
11/299
11/451
11/645
11/620, 645
11/621,622
W507
11/300
Volume/Page No.
of Response
1/72
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/70
1/69
1/69
1/74
1/72
1/69
1/129
1/72
1/72, 129
1/129
1/69
1/69, 72
1/72
1/69
1/129
1/69
1/69
1/69
1/69
1/72
1/69, 74
1/69
1/69
1/72
1/69
1/69
1/72
1/147
1/130, 147
1/132
1/74
1/69
25
-------
Comment Letters Index
Name
Linda K.
Joyce
Cheryl
Madeline
Larry
Fred
Glenn
Dennis
Jeff
Penny
Shelly
Loma J.
Shirley A.
George
Julie
Tonya
Julie
Kenneth
Chris
Randy
LoisC.
Roberta
Helen
Vera
Elizabeth M.
John
Bruce
Ronald A.
Edwin A.
Fairie
Evelyn
Walter E.
Jim
Tammy
GaryL.
Justin W.
Michael R.
Nancy C.
Richard
Jimmy
Jim
Rankin
Rankin
Rector
Reed
Rehm
Rehner
Reid
Reynolds
Reynolds
Reynolds
Reynolds
Rhine
Robbins
Robinson
Robinson
Rocheur
Ross
Ross
Roth
Roth
Roth
Roth
Rouse
Roy
Sala
Sala
Scherer
Schiffer
Schoonover
Schoonover
Schroth
Schroth
Scon
Scott
Sears
Seitz
Seitz
Seitz
Seitz
Sell
Sherrill
Volume/Page No.
of Comment
11/301
11/452
11/302
11/617
11/303
11/618
11/453
11/304
11/305
11/306
11/305
11/454
11/307
11/308
11/308
11/455
11/456
11/456,631
11/309
11/310
11/457
11/458, 459
11/617
11/460
11/311
11/312
11/313
II/461
11/314
11/314
11/315
11/315
11/316
II/617, 632
11/508
11/317
11/318
11/319
W320
11/208
11/462
Volume/Page No.
of Response
1/69
1/72
1/69
1/129
1/69
1/129
1/72
1/69
1/69
1/69
1/69
y?2
1/69
1/69
1/69
1/72
1/72
1/72, 143
1/69
1/69
1/72
' 1/72
1/129
1/72
1/69
1/69
1/69
1/72
1/69
1/69
1/69
1/69
1/69
1/129, 144
1/74
1/69
1/69
1/69
U69
U69
1/72
26
-------
Comment Letters Index
Name
Charles
ielane
Lisa G.
vlargaret
Svron
Barbara
Scott B.
iernadette M.
Lynne
Michael C.
Pedro
Meredith
ivelvn
Cim
Wm.
Cody
Pamela
fohn L.
V. Ann
-ori A.
PaulJ.
Phyllis
Cindy
vlarian
Dolores Ann
Jack
David
Janelle
Sandra
7red
Dolores T.
Everett
Keith
Man-
Gordon
Nelva
Cheryl
Charles
John W.
Mabel
William F.
Shields
Shields
Shultz
Shy
Simpson
Smith
Smith
Sonefeld .
Sorber
Sorig
Sow
Steinman
Stewart
Stockley
Stockley .
Stoumbaugh
Stoumbaugh
Sweet
Swinsdorf
Tagawa
Thiele
Thompson
Thresher
Tinklenberg
Tippett
Tippett
Turecek
Turecek
Turecek
Tute
iTuxhom
Tuxhorn
Ulmer
Ulmer
Van Sickle
Van Sickle
Vashus
Vest
Vest
Vest
Vest
Volume/Page No.
of Comment
11/633
11/633
11/321
11/322
11/323,617
11/324
11/634
11/234, 325
11/326
11/327
11/328
11/329
11/486
11/463
11/464
11/330
H/331
11/498
H/234, 325
11/637
11/499
11/332
11/465
11/500
11/333, 618, 643
11/334
11/335
11/335
11/336
11/337
11/338
11/339
11/340
11/341,645
11/342
11/343
II/466
11/385, 467
11/386, 468
IU344, 469
IV345
Volume/Page No.
of Response
yi44
1/144
1/69
1/69
1/69
1/69
1/145
1/69
1/69
1/69
1/69
1/69
1/74
1/72
1/72
1/69
1/69
1/74
1/69
1/146
1/74
1/69
1/72
1/74
1/69, 129, 146
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69
1/69, 147
1/69
1/69
Mil
1/71,72
1/71, 72
1/69, 72
1/69
27
-------
Comment Letters Index
Name
S.
Bill
Roland
Richard N.
Brad
Traci
Sharon J.
Charlotte
Debra
Barbara
JonB.
Harold A.
Hayley J.
Theresa
Helen K.
Tara
Paul J.
Greg B.
Sharlene
Melvin J.
Cynthia
Dennis
Richard G.
Alberta
Brad
Elaine M.
Robert L.
Illegible Names-
Type A
Illegible Names-
Type B
Vogt
Voth
Wadsworth
Walker
Weisensee
Weisensee
Whalen
Wheeler
White
White
Whitehead
Wilbom
Whitehead
Williams
Witherspoon .
Witherspoon
Wolf
Wolfer
Wood
Wood
Worley
Worley
Wright
Young
Young
Zeucher
Zeucher
Letters
Letters >
Volume/Page No.
of Comment
11/346
11/347, 470
11/646
11/647
11/348
11/349
11/471
11/563
11/350
11/648, 649
H/351
11/473
11/472
11/352
11/474
11/475
11/563
11/353
11/354
11/476
11/355
11/356
11/208
11/357
11/651
11/358
H/359
11/360
11/477
Volume/Page No.
of Response
1/69
1/69, 72
1/147
1/148
1/69
1/69
1/72
1/87
1/69
1/148
1/69
1/72
1/72
1/69
1/72
1/72
1/87
1/69
1/69
1/72
1/69
1/69
1/69
1/69
1/148
1/69
1/69
1/69
1/72
28
-------
Acronyms and Abbreviations
DENDividrs2.doc/l
-------
Acronyms and Abbreviations
ACGffl American Conference of Governmental Industrial Hygienists
AFL-CIO American Federation of Labor and Congress Industrial Organizations
ALARA as low as reasonably achievable
ARAR applicable or relevant and appropriate requirement
ASC additional site characterization
BREACH Bombing Range Environmental Action for Community Health
CBSGW Colorado Basic Standard for Ground Water
CDPHE Colorado Department of Public Health and Environment
CDPS Colorado Discharge Permit System
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act of
1980, as amended
CFR Code of Federal Regulations ,
CLLEAN Citizens for Lowry Landfill Environmental Action Now
CWM Chemical Waste Management, Inc.
COC chemical of concern
CSU Colorado State University
CWA Clean Water Act
Denver City and County of Denver, Colorado
DIA Denver International Airport
DOE United States Department of Energy
DOT Department of Transportation
ECCV East Cherry Creek Valley Water and Sanitation District
EE/CA Engineering Evaluation/Cost Analysis
EPA United States Environmental Protection Agency
ESD Explanation of Significant Differences
FESUP Family Farmers for Environmentally Safe Use of Property
FTPA former tire pile area
HLA Harding Lawson Associates
H&S Health and Safety
ICRP International Commission on Radiological Protection
ISC3ST Industrial Source Complex (Release 3) Short Term dispersion model
Lowry Site Lowry Landfill Superfund Site
MCL maximum contaminant level
MDA minimum detectable activity
MDL minimum detection level
Metro Metro Wastewater Reclamation District (MWRD)
mrem millirem, I/I,000th rem
|ag/g micrograms per gram
NAAQS National Ambient Air Quality Standards
NCP National Oil and Hazardous Substances Pollution Contingency Plan
NCRP National Council on Radiation and Measurements
NESHAP National Emission Standard for Hazardous Air Pollutants
NPDES National Pollutant Discharge Elimination System
H:\DA\WORDPWIN\007.WPD
-------
NIOSH National Institute for Occupational Safety and Health
NPL National Priorities List
NRC Nuclear Regulatory Commission
OCAW Oil, Chemical & Atomic Workers International Union
O&M operation and maintenance
OSHA Occupational Safety and Health Administration
OU operable unit
PCB polychlorinated biphenyl
pCi picoCurie
pCi/g picoCuries per gram
pCi/L picoCuries per liter
PEMS Pretreatment Enforcement Management System
POTW Publicly-Owned Treatment Works
ppm parts per million .
PQL practical quantitation limit
PRP potentially responsible party
QNCR Quarterly Noncompliance Report
rad radiation absorbed dose
RCRA Resource Conservation and Recovery Act of 1976, as amended
RD/RA remedial design/remedial action
rem radiation equivalent man
RI/FS remedial investigation/feasibility study
RME reasonable maximum exposure
ROD Record of Decision
TAG Technical Assistance Grant
TCLP Toxic Characteristics Leaching Procedure
TMV toxicity, mobility, and volume
TSDF Treatment, Storage, or Disposal Facility
Mg/L micrograms per liter
USGS United States Geological Survey
WET whole effluent toxicity
WMC Waste Management of Colorado, Inc.
H:\DA\WORDPW1N\007.WPD
30
-------
Responses
DENDividrs2.doc/l
-------
April 2,1997 Public Meeting Transcript
Questions and Response
During the public meeting on April 2, 1997, a number of questions were asked. This section of
the responsiveness summary provides responses to those questions. The transcript of the meeting
is presented in Volume n of this responsiveness summary. In the following pages, the questions
are in italics and the responses are in regular text. The "T" following the question refers to the
public meeting transcript, and the number refers to the page where the question can be found. In
some cases, the question is taken verbatim from the transcript text. In other cases, the question is
a summary of large sections of text.
A number of questions refer to similar subjects. In these cases, a reference is made in the
response to the appropriate section of the executive summary, which includes the response to
these subjects.
1. Will Metro [Metro Wastewater Reclamation District] be protective of worker health and
safety in the disposal of the waste from the Lowry Landfill Site? T 30
To be protective of worker health and safety, discharge from the Lowry Landfill Superfund Site
(Lowry Site or Site) must meet standards established by Metro pursuant to the National
Pretreatment Program1 of the Clean Water Act (1977, as amended). These standards were
developed using the following guidance:
United States Environmental Protection Agency's (EPA's) Guidance to Protect POTW
[Publicly Owned Treatment Works] Workers from Toxic and Reactive Gases and Vapors
(EPA, 1992b)
American Conference of Governmental Industrial Hygienists (ACGIH) occupational
guidelines that are used by the Occupational Safety and Health Administration (OSHA)
and the National Institute for Occupational Safety and Health (NIOSH)
I
Further documentation of the methods used by Metro to calculate the pretreatment standards are
included in Attachment A.
2. Do you know what will be in the waste water being discharged to Metro from the Lowry
Site? ' T31
The pretreated ground water to be discharged to Metro from the Lowry Site has been analyzed.
A summary of the data is attached as Table 1 (at the end of the transcript responses). A few
Bolded terms are defined in the Glossary.
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examples of the compounds that exceed site performance standards in the ground water before
pretreatment are:
1,1-Dichloroethylene at 167 micrograms per liter (ug/L) (performance standard = 7 ug/L)
1,2-Dichloroethane at 139 (Jg/L (performance standard = 0.4 ug/L)
Benzene at 196 ug/L (performance standard = 5 ug/L)
Pentachlorophenol at 188 ug/L (performance standard = 1 ug/L)
Chloride at 1,514,000 ug/L (performance standard = 250,000 ug/L)
Iron at 6,500 ug/L (performance standard = 300 ug/L)
Nitrate at 45,300 ug/L (performance standard = 10,000 ug/L)
Sulfate at 720,000 ug/L (performance standard = 250,000 ug/L)
These compounds will have to be treated to pretreatment standards before the ground water can
be discharged to the POTWs. Pretreatment standards give an indication of what would be
allowed to be in the discharge. However, the pretreatment process selected during remedial
design will determine how far below the pretreatment limits the concentrations of organic
compounds will actually be. Many contaminants in the ground water to be extracted for
treatment are expected to be present at concentrations below the pretreatment standards.
Pretreatment to reduce the concentrations of any contaminants that exceed pretreatment standards
will provide the added benefit of further reducing the concentrations of those contaminants that
do not exceed pretreatment standards.
A more detailed listing of data can be found in Appendix A of the "Draft Evaluation of the
POTW Treatment Option" (Parsons ES, 1996).
3. When we produce at our oil refinery a barrel of either contaminated water or sludge, our
company pays about $500, or maybe more,"to take it out to Last Chance hazardous waste
facility. When that same barrel goes into Metro, they can take that same barrel and go
and place it across the farmlands in Deer Trail. And that is not deemed to be
contaminated waste or hazardous waste? T 32
*
Metro is not permitted to accept hazardous waste or sludges from industrial processes. Any
discharge to Metro must meet industrial pretreatment requirements. Hazardous waste is not
being distributed across farmlands in Deer Trail, Colorado. The ground water from the Lowry
Site does not meet any of the characteristics of a hazardous waste (ignitability, corrosivity,
reactivity, and toxicity). The Lowry Site ground water will be treated to specified pretreatment
limits and then discharged to the sewer system in accordance with the National Pretreatment
Program. Metro discharges to the South Platte River in accordance with requirements of the
National Pollutant Discharge Elimination System (NPDES) Program of the Clean Water Act
(1977, as amended). The addition of the Lowry Site pretreated water to Metro will not cause
Metro to either exceed requirements in its discharge permit or produce biosolids that do not meet
"exceptional quality" criteria.
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The Metro biosolids that are spread across the land at Deer Trail, Colorado, are classified, under
Federal and State regulations, as "exceptional quality," meaning the concentrations of pollutants
in the biosolids are so low that the biosolids can be applied beneficially to land anywhere, even
home gardens. The biosolids are not a hazardous waste.
4. The Lowry Landfill Site background samples are located on the Buckley bombing range,
which is itself a source of contamination to ground water. Does this compromise the
Lowry background samples? T 36
Background wells were identified through a careful and detailed process that included an
awareness of the location of the bombing range in relation to the Lowry Site (see Comment #5
for an explanation of background). Statistical analyses were used to evaluate the analytical
results from the background wells. In 1994, the Respondents to the "EPA Region 8
Administrative Order for Remedial Design/Remedial Action for the Lowry Landfill Superfund
Site, Docket No. CERCLA [Comprehensive Environmental Response, Compensation, and
Liability Act of 1980, as amended] Vm-95-05" (RD/RA Order) (EPA, 1994b) installed new
wells along the western and southern site boundaries. These wells are not located on the
Bombing Range, have been monitored on a quarterly basis, and have shown similar background
concentration results to those wells located at the southern boundary of the Lowry Site. In
addition, no ordnance (e.g., bombs) were encountered during dirt-moving activities performed in
connection with landfilling operations.
5. Now, this study says that in 100 percent of the ground-water samples that were taken,
there is plutonium in this landfill. And this is going to be piped into a sanitary sewer
system and then to the Metro workers where they will be exposed to this contaminated
ground water and then trucked out to Deer Trail where it's going to be applied onto
farmland. That has not been discussed tonight. T 37
Plutonium was not detected in 100 percent of the ground-water samples from the Lowry Site.
Plutonium was detected at concentra!ions comparable to background concentrations in 30 of 100
ground-water samples (19 of 42 source area samples, 1 of 13 downgradient upper Dawson
samples, 6 of 29 lower Dawson samples, 3 of 12 deep ground-water samples, and 1 of 4
upgradient samples) (EPA, 1993). Background concentrations are those concentrations that
naturally occur in the environment or are present as a result of activities unrelated to a site. In the
30 percent of the Lowry Site ground-water samples with detectable levels of plutonium, the
concentrations are so low that it is impossible to say for sure whether what is being detected is
really plutonium or the result of analytical uncertainty.
Analytical uncertainty must be considered in interpretation of plutonium results, as measurement
of plutonium at near-background levels is a very difficult and complicated process. Accurate
results for low-level plutonium measurements require carefully working through a series of steps
in a radiochemical extraction process, and eventually extracting or recovering a purified sample
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that can be counted using a low-level alpha spectroscopy system. Successfully producing a
purified sample is not a matter of simply following a chemistry procedure; this process requires
an experienced radiochemist and is often as much an art as a science. Errors or uncertainties can
be introduced into the final measurement result both by the radiochemical extraction process, and
by the statistical nature of radioactive decay. Because these errors can be significant relative to
the actual sample result, most analytical laboratories report an error or uncertainty term with the
measurement result. This uncertainty term typically only accounts for that portion of the
analytical uncertainty associated with the radioactivity counting process.
For low-level plutonium measurements, the counting uncertainty can sometimes approach or
even exceed 100 percent of the sample result. As an example, a result with a reported activity of
90 picocuries per liter (pCi/L), with an uncertainty term of +/- 80 pCi/L would imply that the true
sample activity lies within the range of 10 pCi/L (90 - 80) to 170 pCi/L (90 + 80). If the detection
level for this procedure was greater than 10 pCi/L, then there is a chance that there is really no
detectable radioactivity in the sample. This is especially true when the uncertainties associated
with the complicated radiochemical extraction process (which are not included in the error term)
are also considered.
It is important to point out that results like the example shown above are not ignored, but they do
provide a cause for concern over whether any radioactivity is really present. When such results
are reported, they must be considered questionable until additional information is obtained to
support or refute the preliminary indication of the presence of radioactivity. Additional review of
the data is needed (including a detailed review of the radiochemistry logs and recovery data,
condition at the laboratory at the time of sample preparation and counting, and other factors that
could influence the final results). Through this process, a body of evidence can be collected that
should provide sufficient information for decision-making on the appropriate remedial action.
This is the process that has been followed at the Lowry Site. A large body of data has been
accumulated to show that radionuclides are not present in ground water under the Lowry Site in
concentrations greater than those seen from background conditions (including contributions from
past atmospheric weapons testing).
The source of the radiation that has been detected in the Lowry Site samples is most likely the
same as the source of the background radiation that can be detected in the environment.
Background radiation has a number of possible sources. These sources include atomic fallout
from nuclear testing; cosmic radiation", which is radiation from space, primarily from outside of
our solar system; and, geology, in Denver levels of radiation are naturally elevated as the rocks in
our state contain radioactive minerals.
Radionuclides, including plutonium, will be monitored in the effluent from the Lowry Site. If
radionuclides are detected at unacceptable levels, then the water will not be sent to the sewer
until action is taken to ensure radionuclides are reduced to ROD performance standards or
pretreatment standards.
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6. A retired highway patrolman for the State of Colorado alleged in written documents to
the health department that Rocky Flats was dumping radioactive waste precisely along
the same areas ofQuincy Road where background levels have detected radioactive
constituents. What impact does this have on the Lowry background samples? T 38
EPA conducted field investigations that included soil sampling in the areas of alleged dumping.
Results from background soil samples along Quincy Avenue show no evidence of surface or
buried radioactive materials. Additionally, man-made radionuclides have not been confirmed
present in ground water above background levels at the Lowry Site.
The former highway patrolman's 1977 report of alleged dumping of radioactive waste in 1960
and 1961 could not be corroborated by any other'witness or by any sampling and analysis. EPA
interviewed the former highway patrolman and conducted research on Rocky Flats operations to
see if a connection to Rocky Flats could be established. Comprehensive review of information
provided in response to the CERCLA 104(e) questionnaire indicates that no radioactive waste
from Rocky Flats was disposed at the Lowry Site. Based on this body of information, the former
highway patrolman's story appears to have no impact on the Lowry Site background samples.
7. What is the source of the radiation in the Lowry samples? T 38
The Lowry Landfill Baseline Risk Assessment, Volume 2C (EPA, 1993) concluded that the
sources of the radiation that have been detected in the Lowry Site samples are most likely the
same as the sources of the background radiation that can be detected in the environment.
Radiation naturally occurs in the environment, and activities such as past atmospheric nuclear
weapons tests have contributed to the background levels of radiation. The primary sources of
background radiation that could impact Lowry Site samples are:
Terrestrial sources of radiation, including rocks and soil that naturally contain radioactive
minerals
Cosmic radiation, which is radiation from outer space
Radioactive fallout from past atmospheric nuclear weapons testing
Naturally-occurring radionuclides such as uranium, thorium, and radium are present in rocks and
soil in varying quantities across the world. In the Denver area, these radionuclides are present in
soil in higher concentrations than in most areas of the United States due to the geology of the
Rocky Mountain area. These radionuclides contribute to the overall radioactivity in any soil or
water sample from the Lowry Site, and could contribute interferences that increase the overall
error in more difficult measurements such as plutonium and americium. As an example, the
naturally occurring radium-224 isotope is sometimes misidentified as americium-241 because it
emits an alpha particle with almost the same energy as the americium alpha particle.
Cosmic radiation contributes quantities of radionuclides such as tritium and carbon-14. These
radionuclides are present in soil and water, and may have contributed to the detection of
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radionuclides at the Lowry Site. As one example, tritium is present naturally as a result of cosmic
radiation and past weapons testing. Tritium can be an interference in the analytical procedure for
plutonium-241. It is possible that natural background levels of tritium could have contributed to
the positive detections of plutonium-241 at the Lowry Site.
Past atmospheric testing of nuclear weapons has caused detectable amounts of man-made
radionuclides such as plutonium, americium, and tritium to be dispersed in variable amounts
around the world. These radionuclides are detectable in trace quantities in soil and other media,
and this source may be a contributor to the sporadic detections of americium and plutonium that
have been seen in Lowry samples.
8. Why are we covering up the plutonium being in the Lowry Landfill? T 38
EPA has never covered up the fact that plutonium may be present at low levels at the Lowry Site.
This information can be found in several fact sheets, including:
Update No. 2 (EPA, 1988b)
Preliminary Endangerment Assessment (EPA, 1989b)
Update No. 3 (EPA, 1990a)
Fact sheets are notices that are sent out periodically to the public and interested parties to provide
information about the Lowry Site. In addition to the fact sheets, information on radionuclides
detected at the Lowry Site can be found in numerous documents that are part of the Public
Record, which is available at the EPA Superfund Records Center2 and the Aurora Public
Library3. These documents include the following:
Preliminary Endangerment Assessment (EPA, 1989b)
Remedial Investigation Report for Operable Unit (OUs) 1 and 6 (HLA, 1992a)
Evaluation of the Data Quality and Occurrences of Transuranic Radionuclides in the
Shallow Groundwater and Subsurface Liquids-and Deep Groundwater Operable Units
(HLA, 1992b)
Remedial Investigation Report for OUs 2 and 3 (amended by EPA's comments, May
1993)(HSI/CDM, 1993)
"EPA Superfund Records Center
999 18th Street
Denver. Colorado 80202
303/312-6473
Aurora Public Library
14949 East Alameda Drive
Aurora, Colorado 80012
303/739-6600
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Remedial Investigation Report for OUs 4 and 5 (amended by EPA's comments, May
1993) (COM, 1993)
Draft Baseline Risk Assessment Sitewide Risk Issues (EPA, 1993)
Record of Decision (ROD) for the Lowry Landfill Site (EPA, I994a)
Due to continuing questions about plutonium, EPA has conducted more extensive review and
investigation of Lowry Site conditions than is typical for most CERCLA sites. This additional
review and investigation has included independent data evaluations by qualified health physicists
and radiochemists, and investigation of alleged dumping activities by the Rocky Flats Plant. Far
from covering up information, EPA has expended considerable resources in attempting to
confirm or refute data related to plutonium at the Lowry Site. These efforts have not provided
evidence to support claims that plutonium is present at the Site at concentrations greater than
background levels. In addition, even though strong evidence is not available to support
designating plutonium and other transuranics as contaminants of concern, these radionuclides
were evaluated as pan of the baseline risk assessment. The baseline risk assessment treated these
radionuclides as if they were present and contaminants of concern at the Site.
The executive summary in the Draft Baseline Risk Assessment Sitewide Risk Issues (April 1993,
page xii) (EPA, 1993) sums up the conclusions of the radionuclide risk: "Estimated radionuclide
risks for onsite media were about the same compared to those risks expected due to exposure to
naturally occurring levels of radionuclides in the Denver area. Therefore, relative to background
conditions, radionuclide risk contributions do not add to the overall site-related risks."
9. This report, by the way, was done by CH2M HILL, Metro uses CH2M HILL as a
contractor to Metro. So, clearly that contractor is considered to be a reliable contractor.
T38
CH2M HELL has worked for Metro in the past, but is currently only working on an odor control
problem for Metro. CH2M HILL has no influence over the Metro Board's acceptance of the
Lowry pretreated ground water for treatment at Metro. .During the contracting process involving
EPA and CH2M HILL, EPA evaluated CH2M HILL and found no conflict of interest.
10. If we are going to build an underground pipeline that would go west from the landfill
where we know there is a contaminated ground-water plume already, are we then going
to invite the possible transmission of that contaminated ground-water plume through the
pipeline channel itself to contaminate areas that are not presently contaminated?
Of course, that ground water is common to the water supply of the East Cherry Creek
Valley Water and Sanitation District, 100 percent of which is supplied by well, with some
other sources, with ground water supplying tens of thousands of homes in that area. Is
that a source of concern ? Could that be a potential channel of the contaminated ground
water to uncontaminated areas so far? T 39
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The underground pipeline connecting the Lowry Site to the Aurora sewer system will be routed
through an area of the Site that is not contaminated. The location was selected by drilling
boreholes along the pipeline alignment. Soil samples were collected and analyzed to make sure
that the selected location was not contaminated. Contamination was not detected in the area of
the pipeline alignment; therefore, the pipeline will not act as a conduit for contamination to leave
the Site.
11. / was shocked to find that the workers had not been notified by the management of this
proposal, and I think that is a source of concern when it comes to looking at whether or
not there have been studies done of the worker health and safety. My investigation is that
there has not. T 39
The Metro Board does not specifically notify the workers when the Board votes to accept water
from different sources for treatment. Metro has developed preliminary pretreatment standards
for the discharge from the Lowry Site. These discharge standards include protection of workers
from adverse health and safety effects and meet the requirements of the National Pretreatment
Program. The standards were developed using the following guidance:
EPA's Guidance to Protect POTW Workers from Toxic and Reactive Gases and Vapors
(EPA, 1992b)
ACGEH occupational guidelines that are used by the OSHA and NIOSH
Further documentation of the methods used by Metro to calculate the pretreatment standards are
included in Attachment A.
12. Is there enough money in the fund collected from polluters to build an upgraded
treatment plant? T40
EPA has not collected money from the polluters to build an upgraded treatment plant. Thirty-
four of the largest potentially responsible parties (PRPs) were issued a unilateral administrative
order (RD/RA Order) in November of 1994 (EPA, 1994b). This legal document directs the
PRPs to design and implement the sitewide remedy as described in the March 10, 1994 ROD
(EPA, 1994a). The City and County of Denver (Denver), Waste Management of Colorado, Inc.
(WMC), and Chemical Waste Management, Inc. (CWM), on behalf of themselves and 24 of the
other PRPs, are implementing the sitewide design and clean up in accordance with the RD/RA
Order. The parties responsible for the cleanup have demonstrated financial ability to perform the
cleanup, which could include building an upgraded treatment plant.
13. That waste water from Lowry, if it were trucked on the ground to the Metro plant, would
be considered a Resource Conservation and Recovery Act hazardous waste, which has
much stricter regulations for that waste. At Metro, the EPA itself has indicated that if it
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were stored at Metro it would come under much more stringent requirements under
RCRA. If you dump it into the sewer system under those sets of final and prer emulations,
it all of a sudden becomes not a hazardous waste. T 40
If the pretreated ground water from the Lowry Site was trucked to Metro, it would not be subject
to more stringent requirements. The ground water from the Lowry Site does not meet any of the
characteristics of a hazardous waste (ignitability, corrosivity, reactivity, and toxicity). Once the
ground water is pretreated to the pretreatment limits, the water will then be regulated under the
NPDES Program of the Clean Water Act (1977, as amended).
EPA and the Colorado Department of Public Health and Environment (CDPHE) do not
understand what the commenter is referring to when he says " ... the EPA itself has indicated that
if it were stored at Metro it would come under much more stringent requirements under RCRA."
A hazardous waste determination (see 40 CFR Pan 261) must be made independent of the mode
of transportation and must be made before transportation occurs. The identification of hazardous
waste determines the transportation requirements.
14. / think this proposal is inviting potential future liability in terms of the farmland out at
Deer Trail. T41
Table ES-2 in the Executive Summary shows that the addition of contaminants from the
pretreated Lowry Site ground water to Metro will not affect the "exceptional quality" status of
Metro's biosolids. Because the contents of the biosolids will meet Federal and State standards,
EPA does not now envision that there would be any liability relating to the farmland to which the
biosolids are applied.
Biosolids are produced in the United States at a rate of 6,856,169 dry tons per year. Of those
solids, 55 percent are land applied. In Colorado, 78 percent of the 60,273 dry tons per year of
biosolids are land applied. Land application rates in other states range from 0 percent (Alaska) to
100 percent (Delaware, North Dakotai and Oregon).
For many years, several major urban areas have sold or given away biosolids products for use as
soil conditioners, organic fertilizers orpotting media (Bastian, 1997):
Salem, Oregon (BIOGRO)
Madison and Milwaukee, Wisconsin (AGRO-LIFE)
Virginia Beach, Virginia (NUTRI-GREEN)
Other cities are following suit and beginning to market their biosolids products. Efforts by
private companies to make and market products from biosolids are also more common now.
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Over the past 20 years, biosolids management practices have changed significantly, moving from
disposal toward more beneficial use. Beneficial use of biosolids such as land application is
continuing to rise. When polled by BioCycle (Goldstein. 1997), 30 states indicated that
beneficial use rates will increase and more biosolids will be land applied in the future.
15. Metro has no capability of removing toxic metals. The toxic metals will end out in the
sludge in Deer Trail if there is no inorganic removal process at the Metro plant. T 41
The water that will be piped from Lowry to Metro will not contain high levels of toxic metals.
Metro will monitor these metals as required in the pretreatment permits to ensure that the
treatment processes at Metro are capable of handling the Lowry Site water. We assume the
commenter is referring to heavy or trace metals, which are typically understood to mean the fifth
line and below on the periodic table, and include mercury, arsenic, and cadmium. The water will
contain high levels of chlorides and sulfates (not considered toxic metals), contaminants that will
be removed or reduced at the Metro facility. The levels of metals will be below the levels
required in the pretreatment permits for discharge of water to the sewer system (See Executive
Summary - Human Health, Environmental, and Biosolids Concerns).
16. Are you denying that there'splutonium, americium, tritium, strontium, cesium and
cerium in the landfill? T 45
Plutonium, americium, tritium, strontium, cesium, and cerium (types of radionuclides) have all
been detected in various media at the Lowry Site, but at levels that do not pose a risk to human
health or the environment. These radionuclides are present as part of the spectrum of background
radionuclides that exist in the environment primarily due to past atmospheric weapons testing.
They are present in soils and other media not only at the Lowry Site, but in most areas of the
country at variable concentrations. The National Council on Radiation Protection and
Measurements has published two reports (NCRP, 1987a; and NCRP, 1987b) that provide general
information on the concentrations and doses associated with background radionuclides in the
United States and Canada. Specific data on concentrations of plutonium, americium, tritium,
strontium, cesium, and cerium and the Lowry Site (including background locations) can be found
in the Draft Baseline Risk Assessment Sitewide Risk Issues (EPA, 1993).
17. Are you claiming that there are measurable levels of plutonium in the ground water, in
the background throughout the Denver Metropolitan area ? T 46
Detectable levels of plutonium have been measured in ground water from background samples in
the Denver metropolitan area. While it is possible to detect plutonium in ground water and soils
from background areas, this does not mean that there is a potential health threat associated with
such low level detections. There are measurable quantities of chemicals and radionuclides other
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than plutonium in ground water in the Denver area, and in all other ground-water systems in the
United States.
EPA has established standards for drinking water that limit the concentrations of chemical and
radiological contaminants in drinking water to levels that are safe for human consumption. These
are called maximum contaminant levels or MCLs. For radionuclides, EPA has established a
performance standard of 15 pCi/L for alpha-emitting radionuclides (excluding uranium and
radon). The ROD (EPA, 1994a) also establishes performance standards for beta and photon
emitters americium-241, cesium-134, lead-210, plutonium-238,-239, and -240, potassium-40,
radium-226 and -228, strontium-90, thorium-228, -230, and -232, tritium, and uranium-234, -
235, and -238. These are the performance standards that must be met before water can be sent
from the Lowry Site to Metro's POTW.
18. One particle of plutonium can cause cancer. T 47
It is mathematically impossible to either confirm or refute such a statement since the process of
cancer initiation is not understood sufficiently well at the molecular level to determine exactly
what specific event starts a cancer cell growing. It is misleading to state that one particle of
plutonium can cause cancer and that has not been confirmed in any scientific studies. Based on
our current understanding of biological repair mechanisms, it is also highly unlikely. What we
do know is that radiation can cause cancer at high doses and dose rates. Because plutonium is a
radioactive substance, it is considered a human carcinogen. We know from the many studies of
human populations exposed to high levels of radiation that there is an increased chance of getting
cancer as radiation dose is increased. However, there is no evidence to support an assertion that
one particle of plutonium can cause cancer, or that per millirem (mrem) of dose, plutonium is a
more potent carcinogen than any other radionuclide (Health Physics Society, 1995).
Radioactive materials are capable of causing health effects (including cancer) because they emit
energy in the form of radiation. It is this radiation that actually causes cell or tissue damage and
helps to initiate a cancer. Cancer may occur after sufficient energy (dose) from radiation has been
received by a tissue or organ to cause1 events such as unrepaired DNA strand breaks or formation
of oxidizing agents that cause additional cellular damage. Under certain conditions, these events
may lead to initiation of a tumor. The amount of dose is the critical point in assessing whether or
not a health effect (cancer or other) is likely to occur. This is true for all radioactive materials,
including plutonium.
We are all exposed to radiation every day of our lives. On average, we receive approximately
360 millirem (mrem) per year of radiation dose in the United States. For perspective, the lowest
doses in the studies that have shown a correlation between radiation exposure and cancer have
been on the order of 1,000 to 20,000 mrem. Based on the results of these human and animal
studies, there is continued scientific debate on whether or not there is a safe threshold level of
radiation exposure. Some scientists feel that there is sufficient evidence to show that there is a
level of radiation exposure below which no health effects occur. Until such theories are proven,
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current regulatory limits are based on the assumption that there is an increase in risk for every
increase in dose, no matter how small. Rulemaking efforts are designed to limit increased risk to
levels that typically range from one additional cancer in a population of one million people (106),
to a few cancers in a population of 10,000 people (10"4).
19. We understand that Lowry Landfill is part of the Lowry bombing range. Do you also
understand that Lowry Landfill was built on top of a former chemical warfare testing
area ? T 49
The Lowry Landfill Superfund Site was once part of the Lowry Bombing Range. The Lowry Site
was not part of a former chemical warfare testing area. A history of the Lowry Bombing Range
can be found in the:
Master Work Plan, Engineering Evaluation/Cost Analysis, Former Buckley Field (Lowry
Bombing and Gunnery Range), Aurora, Colorado (COE, 1997)
Archives Search Report, Findings, Buckley Field, Arapahoe County, Colorado (COE,
1995)
These reports can be found at the Aurora Public Library, at the EPA Superfund Records Center,
and at CDPHE.
The following statement is found in the Master Work Plan for the EE/CA (Engineering
Evaluation/Cost Analysis): "Although the ASR (Archive Search Report) stated that possible
CWM (Chemical Warfare Material) (including bombs and agent identification sets) was used at
Former Buckley Field, a more thorough search of the historic use of CWM conducted by
CEHNC (United States Army Engineering and Support Center, Huntsville) indicates that the
most likely use of CWM was only in the camp 2 area (within the Lowry Training Annex)." The
Lowry Training Annex is several miles from the Lowry Landfill Site (see Figure 1).
20. Can the Metro plant effectively treat the toxic wastes as they come in and are treated and
put into the Plane River? I'm concerned about whether or not, as the Plane goes up
towards Deer Trail, the communities up there that are engaged in agricultural pursuits
will have toxic wastes in their area. And, if so, I feel it will be a tragedy.
What is the evidence as of this date and is the accuracy of this evidence verifiable?
Where are the studies? Who has them? T51
The pretreated Lowry Site ground water will not be toxic waste. Metro can effectively treat the
pretreated Lowry Site ground water. Metro will establish pretreatment standards, pursuant to the
Federal Pretreatment Program, that will require Metro to maintain compliance with its discharge
permit. This means that Metro will not allow wastewater to come to its facility that is not
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treatable with the existing processes, or that has chemicals at high enough concentrations to
inhibit treatment (i.e., would be toxic to the activated sludge system), or that could not be
adequately treated to meet discharge standards.
An evaluation of Metro's capabilities to treat pretreated Lowry Site ground water may be found
in the document entitled "Evaluation of the POTW Treatment Option," (Parsons ES, 1996). In
addition, the Metro POTW has been successfully treating wastewater from other industrial
sources for many years. Historical records of Metro's operation are available at EPA's offices.
21. I had a couple questions concerning the first and second ESDs [Explanation of
Significant Difference] specifically referring to levels of contamination in the ground
water. We were wondering how those levels were decided upon because there is
significant change from first numbers and second numbers, and we didn 't quite
understand how those were determined. T 51
The First ESD (August 1995) corrected several performance standards that were listed in the
ROD (EPA, 1994a). These corrections include:
If a MCL or Colorado Basic Standard for Ground Water (CBSGW) exists, then the MCL
or CBSGW was used instead of a risk-based performance standard.
If a performance standard was less than background values, then the performance
standard was changed to be equal to the background value.
If a performance standard was less than the practical quantitation limit (PQLthe limit at
which a laboratory can measure a compound), then the performance standard was
changed to be the PQL.
Typographical errors and duplication of compounds were corrected.
A complete copy of the First ESD can be found in the Records Center. A complete copy of the
Second ESD can be found in Attachment F.
22. We need to consider all of the separate entities that are going to be contributing to
Metro's sewage sludge. T 52
Under the terms of its permit, Metro is responsible for evaluating all wastewater to be received
for treatment. The purpose of these evaluations is to ensure that its facility is capable of treating
the wastewater effectively. The National Pretreatment Program regulates industrial waste
discharges to municipal sewer systems (see Executive Summary - Human Health,
Environmental, and Biosolids Concerns). The Metro Board has determined that its facility is
capable of treating the Lowry Site ground water, while still meeting the requirements of their
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NPDES permit, which allows it to discharge treated water. Metro's operation is regulated by
both EPA and CDPHE.
23. In the draft definition of the POTW treatment option there is mention ofASARCO - the
ASARCO plant that would be a part of the contributors to Metro and a part of the sewage
sludge that would eventually then be going out to the people of Deer Trail. T 52
The ASARCO site is not mentioned in the Lowry Landfill POTW treatment evaluation
document. ASARCO was party to a de minimis settlement at the Lowry Site. However, we are
not sure what is being referred to in this statement. A request for clarification was sent to the
commenter, but a response was not received.
24. There was a study done by CH2M HILL that found plutonium in 100 percent of the soils
samples taken from ASARCO - is the facility of Metro adequate to be treating such things
as plutonium that will be going out to the people of Deer Trail. T 52
It is not clear which study is being referred to in the first part of this question. Several attempts
were made to contact the commenter in order to obtain a clarification of the question. To date,
the commenter has not responded to EPA's inquiries. CH2M HILL has not taken any samples
from the ASARCO site in Denver.
25. What are Metro's limits for plutonium ? T 54
26. Shouldn 't you have conclusive evidence that there isn 't plutonium in there before you let
this plan go through?
T56
Since Metro has not yet developed a standard for plutonium, Metro is evaluating the pretreatment
limit for plutonium. The Lowry Site ROD (EPA, 1994a) establishes performance standards for
radionuclides, including plutonium. If radionuclides are detected at unacceptable levels, the
concentrations will be reduced to pretreatment standards or ROD performance standards before
the water is discharged to Metro.
In response to public concerns about the possible presence of radionuclides at the Site, an
additional evaluation of the radionuclide data from the Lowry Site ground-water database was
performed. This evaluation is presented in Attachment C and is based on the sitewide ground-
water quality database, which contains more than 2,900 records of speciated radionuclide data.
In addition, this database contains another 933 records of gross alpha and gross beta data for
ground water. Based on the information in this database, EPA and CDPHE believe that the Site
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has been sufficiently characterized with respect to radionuclides to adequately assess the
potential impacts to human health and the environment.
27. There could be significant difference region to region in an MCL. The people in Deer
Trail, that county could have a different MCL than Denver and Aurora. Is that correct?
T61
MCLs are federal standards set by EPA under the Safe Drinking Water Act and are the standards
that drinking water supplies must meet. These standards are enforced nationally and do not vary
from region to region.
In addition, the CDPHE is not precluded from setting a ground-water standard that is more
restrictive than the corresponding Federal MCL. Some State standards for ground water do vary
based upon the classification of a particular aquifer or the establishment of site-specific
standards. Any given State standard must be at least as protective as the corresponding federal
standard.
28. Sewer systems leak all the time. So these contaminants that are going through the sewer
systems underneath Aurora on their way to the Metro treatment plant are going to leak
out into the soil and eventually into the ground water. You are going to have utility
workers who are going to work on these sewers. The utility workers are going to be
exposed to this stuff. ' T 68
There is the possibility that a sewer might break or leak over time; however, there is no
additional exposure risk from the pretreated Lowry Site ground water. The concentrations of
contaminants in the water being released from the Lowry Site will meet the pretreatment
standards established for Metro's POTW. The POTW's pretreatment standards for
nonhousehold discharges are considerably more protective of the environment than are the
standards for the raw household sewage that is in the sewer. Lowry Site water will not add to the
risk sewer workers already encounter simply by working around raw sewage.
29. The Metro workers themselves who are going to have to handle this stuff that they
haven't had to handle before have absolutely no protection. They are not covered by
OSHA, period. T 69
Congress has determined that State and local governments, like Metro, are not subject to OSHA
regulations. While the Metro workers are not covered by OSHA, they are covered by Metro's
Chemical Hygiene Plan (MWRD, 1997a). EPA has reviewed this plan and found it to be as
comprehensive as a plan that would be required under OSHA.
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30. The bottom line is - what are the risks for transporting the Lowry hazardous substance
through the sewer system. There is no federal regulation that says EPA or the Colorado
State has to do any risk assessments for the people in Aurora or anywhere along that
pipeline. All they have to do is a risk assessment on the Lowry Landfill for people who
won't even live therefor 10 or 20 years from now. There's no regulation that says they
have to do a human health baseline risk assessment for the Metro workers, the people
that are going to work with this stuff, and treat it. This is a bad idea, there is a $1 million
difference bet\veen doing all the treatment on-site or pumping it through the Metro
system. T 70
The ground water from the Lowry Site does not meet any of the characteristics of a hazardous
waste (ignitability, corrosivity, reactivity, and toxicity). Once the ground water is pretreated to
the pretreatment limits, the water will then be regulated under the NPDES Program of the Clean
Water Act (1977, as amended).
The pretreatment standards were developed to minimize the risk of transportation of wastewater
through the Metro system. Pretreated ground water from the Lowry Site will pose no more, and
very probably less, hazard to people in Aurora or to Metro workers than the existing sewage that
is already in the system.
A risk assessment is not required for adding to the waste stream already in the sewer system
when the added material meets the pretreatment standards. Metro is responsible for evaluating
all of the wastewater it receives for treatment to ensure that its facility is capable of treating the
wastewater effectively. The National Pretreatment Program regulates industrial waste discharges
to municipal sewer systems (see Executive Summary -Human Health, Environmental, and
Biosolids Concerns).
Additionally, while the Metro workers are not covered by OSHA, they are covered by Metro's
Chemical Hygiene Plan (MWRD, 1997a). EPA has reviewed this plan and found it to be as
comprehensive as a plan that would be required under OSHA if Metro was a private entity.
31. Dr. Ed Demos, Division Director of Environmental Services for the Department of
Environmental Health, City and County of Denver, has a room full of studies relating to
the Lowry Site. Since 1980 millions of dollars have been spent studying the site. The
data are available for review in his office. T 71
The comment is noted.
32. A commenter has reviewed the documents and was concerned that the plutonium issue is
not satisfactorily addressed. T 72
See responses to Comment #5, 6, 7, 8, 16, 17, 18, 24, 25, 26, 57, and 59.
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33. What about the studies that show that crops such as wheat and corn do take up heavy
metals into the grain and the kernels of corn9 What impact will the sludge shipped out to
Deer Trail have on these crops? T 72
We are not sure what studies are being referred to in this question. A request for further
information was sent to the commenter, but we have not received a response. Table ES-2 shows
the impact the pretreated Lowry Site waters will have on the Metro biosolids (Executive
Summary - Human Health, Environmental, and Biosolids Concerns). Because the impact of the
Site waters on the biosolids is so low, we expect to see no significant changes in the quality of
biosolids going to Deer Trail.
34. Are crop plants from Deer Trail where the sludge is applied going to be sold on the
market, and will consumers be informed where our corn and wheat come from? T 72
Crops from Deer Trail where biosolids are applied may be sold on the market. Biosolids from
municipal wastewater treatment plants are applied to cropland across the United States and in
many foreign countries. In the United States, EPA has established regulations for biosolids that
are applied to croplands. The quality of the biosolids must meet specific numeric criteria to
ensure protection of human health and the environment. These criteria are listed in Attachment
A. Metro produces "exceptional quality" biosolids as defined in these regulations and meets the
criteria for biosolids placement on croplands. Products made from crops that have been grown
on land that received biosolids applications are not required to be marked. (See the Executive
Summary - Human Health, Environmental, and Biosolids Concerns)
35. A commenter said that he had a series of studies that show that plants do take up metals
from the soil. T 73
We are not sure what specific studies are being referred to in this question. A request for further
information was sent to the commenter, but no response was received. Nevertheless, EPA and
CDPHE are aware that there is evidence that plants take up metals from soil. The numerical
standards for metals established in the Clean Water Act Part 503 Rule (EPA's biosolids
regulations) take into consideration the uptake of metals by various crops. These standards are
established conservatively to prevent unacceptable levels of metals from being taken up by crops
and to prevent human exposure by more than a dozen other potential pathways.
Table ES-2 shows the impact the pretreated Lowry Site waters will have on the Metro biosolids
(Executive Summary - Human Health, Environmental, and Biosolids Concerns). Since the
impact of the Site waters on the biosolids is so low, no significant changes in the quality of
biosolids going to Deer Trail are expected.
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36. If we have these metals being taken up into our crops, are these metals going to enter our
food web7 T73
Yes, metals taken up into crops can enter the food chain. Again, EPA has established regulations
for biosolids that are applied to croplands. The quality of the biosolids must meet specific
numeric criteria to ensure protection of human health and the environment. These criteria are
listed in Attachment A. Metro produces "exceptional quality" biosolids as defined in these
regulations and meets the criteria for biosolids placement on croplands.
37. Sewage sludge has increased levels of heavy metals. T 73
Sewage sludge has heavy metals in it. Whether or not these levels are "increased" when
compared to background depends on the particular heavy metal. Studies done at Colorado State
University (CSU) over the past 14 years show that copper and zinc concentrations in the crops
can be increased when biosolids are added to the cropland. Other heavy metals studied do not
cause increased concentrations in the crops. The existing standards for biosolids do provide
protection for human health and the environment.
38. The studies I see show increases in cadmium, nickel, and copper also. T 74
We are not sure what studies are being referred to in this question. A request for further
information was sent to the commenter, but we have not received a response.
39. Are we going to be informed about where these crop plants are going to be sold if they
are going to be sold in our area? T 76
No tracking of the crop plants produced on land enhanced with biosolids is currently required.
The biosolids produced by Metro have received a rating'of "exceptional quality" by Federal and
State regulators and the quality of the'biosolids will not be impacted by the addition of pretreated
Lowry Site waters (see Executive Summary - Human Health, Environmental, and Biosolids
Concerns). Because the biosolids are approved under existing regulations for application to
farmlands and gardens, no tracking of the crop plants is currently required, nor are there labeling
or other requirements.
40. The sewage sludge issue has been going on for over a decade. At one time they leased
ground from the farmers and convinced the farmers that the sludge would be good
fertilizer, now they are unable to lease any more ground so Denver is buying 50,000
acres to put sludge on. Sludge will continually be produced and the new ground will
wear out and where the additional sludge will be placed. Sludge is not good fertilizer, it
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doesn 't produce good crops. Therefore it's hard to even give it away to a fanner. If the
sludge is put on the ground, kids and cows may eat it. T 77
Metro has never leased ground from farmers. Until Metro began acquiring the property near
Deer Trail, Metro applied all but about 5 percent of its biosolids to privately owned farmland and
charged farmers $3 per acre to apply the biosolids. The 5 percent that was not land applied was
turned into Class A compost. Metro still applies about 40 percent of its biosolids to privately
owned farmland and still charges S3 an acre. There are a number of farmers on Metro's biosolids
application waiting list.
Biosolids will be produced as long as wastewater is cleaned using the technology available today
and in the foreseeable future. Biosolids do not wear out the ground. On the contrary, biosolids
provide organic material and nutrients the soil needs to help it produce crops, increase tilth and
soil structure, and reduce or prevent erosion. Biosolids actually help rebuild soil by adding
organic matter, macronutrients, and micronutrients.
Many people say that biosolids make an excellent fertilizer. Biosolids provide farmers with $60
to $160 per acre worth of fertilizer value, including a host of essential nutrients and
micronutrients that are frequently not provided in commercial fertilizers. In the case of Metro's
biosolids, each dry ton contains about 25 pounds of available nitrogen, smaller amounts of
phosphorus and potassium, and about 1,200 pounds of organic matter. Many of eastern
Colorado's soils are deficient in organic matter. Consequently, biosolids help to repair and
improve the soils by adding organic material. As for crops, biosolids have been shown to
increase yields and, in dryland wheat, protein content. In general, yields in good soils do not
increase as dramatically as they do in poor soils, which show as much as a 100 percent increase
in yield after application of biosolids.
EPA has been studying biosolids for well over 25 years. The 40 CFR Part 503 Regulations
(EPA's biosolids regulations) are based on the results of extensive multimedia risk assessment.
As part of the development of the 40 CFR Part 503 Regulations, EPA conducted a risk
assessment that evaluated 25 pollutants and 14 pathways of exposure. One of the risk scenarios
found that if a person ate biosolids-arnended soil every day for 70 years, that person would have a
one-in-ten-thousand chance of possibly contracting a disease. Farmers do not typically let
children or cattle roam on freshly fertilized fields. Metro restricts access to its property for
30 days after application of biosolids and has posted and fenced its property to prevent public
access. Even if casual contact with biosolids-amended soil were to occur, the chance of one or
two such exposures causing harm is immeasurably small.
41. There is already a lot of garbage distributed on the ground out there, what are you going
to do with what is already on the ground? How are you going to undo that problem ?
Because intrinsically government agencies react, they don 't act to prevent. T 78
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CDPHE investigated this allegation and found no evidence of "garbage distributed on the ground
out there." Metro's wastewater treatment process includes screening and skimming as well as a
grinding operation just prior to undigested solids entering the digester. Any material remaining
in the solids at the point of grinding comes out of the grinders approximately the size of a
fingernail. Nevertheless, if, in the future, it is determined that garbage has accumulated in the
area as a result of Metro's operations, Metro will be required to clean it up.
The 40 CFR Part 503 Regulations (EPA's biosolids regulations) are, in fact, designed to prevent
problems from occurring.
42. How long-is this site in Deer Trail going to be used? How much sludge is going to be
dumped, and at what point under existing regulations will it be determined that the Deer
Trail site isn'(healthy? Are you going to just move to another patch in eastern
Colorado, or are we finally going to come up with solutions? T 79
Biosolids are not being "dumped" at Metro's Deer Trail site. Crops are being planted at the site
and the biosolids are being applied at agronomic rates. Therefore, although biosolids are being
land applied at the site, no dumping is occurring. The original estimate when the land was
purchased was that the site would be able to be used for land application for more than 100 years.
But because 40 percent of Metro's biosolids are being applied on privately owned land, the site
can actually be used for land application well in excess of the planned 100 years, although it is
difficult to say precisely how much longer that would be.
As for how much biosolids will be land applied, that is also difficult to say, because the amount
to be applied depends on the crop that will be grown next. Assuming dryland wheat will be the
dominant crop, the agronomic rate for dryland wheat is one to two dry tons per acre, and the
application would take place only every other year. Also, some of the land will not have
biosolids applied to it because of buffer strips, setbacks, and other erosion-control measures.
Metro monitors the soils at its applications sites before, during, and after application to ensure
that none of the metals of concern ar^ becoming concentrated in the soil and too much nitrogen
and other nutrients are being applied.
Land application of biosolids is the best, most environmentally friendly solution to what society
should do with the mostly organic, nutrient-rich solids that result from treating sewage at a
POTW. More that 25 years of science went into the 40 CFR Part 503 Regulations (EPA's
biosolids regulations) to show that land application is safe for people, animals, and the
environment. Only two other "solutions" are currently available: incineration and monofilling
(surface disposal). Incinerating biosolids (1) wastes a resource that has proven environmental
and economic value and (2) may not be possible in areas such as Denver where there already are
air quality attainment problems. Monofilling (landfilling) biosolids concentrates nutrients such
as nitrates which, when properly managed, provide fertilizer value to the soil. However, when
concentrated too highly, they can leach into ground water and pollute it. It should be noted that
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monofilling is cost-competitive with or even less expensive than land application in many areas,
but many communities have decided to land apply and reuse this resource despite the potential
cost savings of monofilling.
43. Look into a study presented in the New Scientist magazine regarding levels of cadmium
in sheep livers after the sheep grazed on grass fertilized with sewage sludge. T 79
The New Scientist magazine article (Coghlin, 1997) entitled "Lamb's Liver with Cadmium
Garnish" was published on March 22, 1997. The article reported that one research effort had
determined that cadmium levels were elevated in livers from lambs grazing on pasture land
where biosolids are used as fertilizer in the United Kingdom. The pretreated Lowry Site ground
water will not affect the "exceptional quality" standard for cadmium in the Metro biosolids (see
Executive Summary - Human Health, Environmental, and Biosolids Concerns). Metro biosolids
meet Federal and State standards in the United States.
44. A 30-day extension is requested. T 79
In response to public requests, EPA extended the public comment period from April 22 through
May 22, 1997. The public comment period was further extended through June 30, 1997 to allow
the public additional time to review Site information (including new information regarding
treatment of a portion of the water from the Lowry Site in Aurora's POTW). With these
extensions, the public comment period on the Second ESD extended over 90 days.
45. How much have the responsible parties paid into a fund to rectify the problem at the
Lowry Landfill, this includes the private settlement litigation. What is the ballpark
estimate of the difference between the cost of the on-site treatment versus the off-site
treatment? T 80
EPA was not a party to the private contribution litigation taken by Denver, WMC, and CWM
against other responsible parties at the Site. The court has sealed all settlement documents that
describe the amount of settlement monies paid to Denver, WMC, and CWM for the Site cleanup
and EPA does not have access to those" documents. The estimated 30-year cost, including capital
costs and annual operation and maintenance (O&M) costs for the sitewide remedy in the ROD, is
593.848,000. EPA's costs to date (including contractor costs) are approximately $27 million. It
is estimated that the Responsible Parties have spent between $40 and $70 million on remedial
costs (including costs reimbursed to EPA).
As a part of the Second ESD evaluation, estimated capital and O&M costs of Alternatives 1 and
2B were compared. Net present worth costs were estimated by adding the capital costs to the net
present value of the annual O&M costs for 30 years, using an interest rate of 5 percent. The net
present worth cost for Alternative 1 (the POTW option) is estimated at $6,354,000. This
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includes capital costs for a lift station, piping, excavation and construction, the sewer connection
fees, design and construction management costs, O&M costs, equipment repair costs, POTW
treatment fees, and water augmentation costs.
The net present worth cost for Modified Alternative 2B was estimated at about $9,300,000. This
includes capital costs for the reverse osmosis system, an iron removal system and an evaporation
system, design and construction management costs, O&M costs and water augmentation costs.
46. / see from going through the public record that there is a citizens group of residents that
are near, the landfill that has a technical assistance grant to evaluate Lowry issues. Wfiat
is their position on this issue and are they not here tonight?
Didn 't CLLEAN recommend modified Alternative 2 (on-site treatment of inorganic and
organic contaminants) over Alternative /(the POTW option)? T 83
The Superfund law provides for Technical Assistance Grants (TAG) to be awarded to groups
in communities affected by a Superfund Site. The purpose of these grants is to encourage
informed public involvement in decisions at Superfund Sites. In October 1995, a TAG was
awarded to the Citizens for Lowry Landfill Environmental Action Now (CLLEAN). This grant is
being used to fund reviews and analyses by technical experts of the remedial design and
construction at the Lowry Site.
CLLEAN's consultant, Summit Technical Services, reviewed the evaluation of potential
treatment options prepared by the City and County of Denver, Waste Management of Colorado,
Inc., and Chemical Waste Management, Respondents to the Administrative Order for Remedial
Design/Remedial Action. The Respondents' Report is titled, Draft Evaluation of the POTW
Treatment Option (Parsons ES, 1996). After reviewing this report, CLLEAN recommended
modifications to Alternative 2B (onsite treatment for organics and inorganics, onsite discharge of
treated water by injection into the aquifer and offsite disposal of evaporator sludge). CLLEAN
proposed the following modifications to Alternative 2B:
l
Two-stage reverse osmosis system for near complete recovery of the treated water to
eliminate injection water augmentation;
Recycle the steam that would be generated by the evaporator through a heat exchanger to
pre-heat the incoming water stream; and
Use the recovered water to augment the wetlands program.
CLLEAN endorsed Modified Alternative 2B and expressed concerns that the concentrations of
contaminants in Lowry ground water might increase to levels above POTW influent standards.
CLLEAN submitted comments on the Second ESD and these comments are included in
Volume II.
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Representatives from CLLEAN did not attend the public meeting held on April 2, 1997.
47. We represent about 90,000 members across the United States. Our members work in
toxic industries. It is not a subject that we are unfamiliar with. We think there are
serious, serious problems with your proposal, not only problems from the vantage point
of the worker, certainly problems with in the agricultural areas with the farmers. T 84
EPA recognizes the commenters' concerns. All work performed by the Parties to the RD/RA
Order (EPA, 1994b) is done under the strict oversight of EPA and CDPHE. The Parties will be
required to prepare detailed remedial designs that must be reviewed and approved by EPA and
CDPHE. In addition, the construction and operation activities will be conducted in accordance
with rigorous quality assurance/quality control requirements and will be observed by EPA and
CDPHE. The Parties will be required to develop a compliance monitoring program to assure that
the remedy complies with the performance, or cleanup, standards established in the ROD (EPA,
1994a). EPA and CDPHE will make sure the proposal will comply with all Federal and State
regulations to minimize impact to the agricultural community.
48. There is an inextricable connection bet\veen how OCAW [Oil, Chemical, and Atomic
Workers International Union, AFL-C1O] workers have been treated at the Metro's
Reclamation District and how the public will be treated under this proposal. T 84
There is absolutely no connection whatsoever between OCAW's relationship with Metro and
EPA's efforts to be protective of human health and the environment. This includes EPA's
commitment to public involvement. Labor disputes between OCAW and Metro are a separate
issue that should be directed to the Department of Labor and will not be addressed in this
responsiveness summary.
49. Is Metro licensed as a hazardous waste treatment plant? T 84
i
Metro is not a permitted hazardous waste treatment facility under the Resource Conservation and
Recovery Act of 1976, as amended (RCRA). The POTW is regulated under the Clean Water Act
(1977, as amended).
50. Is it correct that the water leaving the Lowry Landfill is not being considered hazardous?
T85
Yes. The ground water from the Lowry Site does not meet any of the characteristics of a
hazardous waste (ignitability, corrosivity, reactivity, and toxicity). Once the ground water is
pretreated to the specified limits in a pretreatment permit from Metro and discharged to the
POTWs, then the water will be regulated under the NPDES Program of the Clean Water Act
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(1977, as amended) (See Executive Summary - Human Health, Environmental, and Biosolids
Concerns).
51. Is there going to be a boundary wall placed around the Site? T 85
Yes, a containment, collection, and diversion system is currently being built along the east, south,
and west boundaries of the Lowry Site. This subsurface boundary system (soil/bentonite slurry
wall) will extend from the ground surface and is keyed two feet into the unweathered Dawson
formation, which ranges in depth from 45 to 74 feet. The purpose of the boundary wall is to
prevent clean ground water from entering the Lowry Site and becoming contaminated. The
boundary wall will also help prevent contaminated ground water from leaving the Site.
52. This stuff is all mixed together in Lowry Landfill. You 've got all this hazardous toxic
waste and they are all together. Inorganics, organics all mixed in together. Heavy-
metals, chemical wastes, radioactive whatever. How can the inorganics and the organics
be treated if they are all mixed up together? Do you first separate the inorganics and
organics from the water on-site and then treat them? Or do you treat them all when they
are all mixed? How is that effective? How can you separate the inorganics from the
organics? Is that effective treatment? And, then, how are they separated if you are going
to separate them? If you are not going to separate them, is it effective if they are not
going to be separated? T 87
A wastewater treatment plant is designed in segments, or process units. These process units treat
wastewater using physical, chemical or biological processes. Different process units target
different compounds. Some units treat inorganic compounds, while others treat organic
compounds or a combination of inorganic and organic compounds.
Waters that contain both inorganic and organic contaminants can be treated effectively. A
wastewater containing both inorganic and organic contaminants flows through a process unit that
removes one or more target compourtds. The remainder of the wastewater (and untreated
contaminants) passes through the next process unit that removes one or more additional target
compounds. This continues as the wastewater goes through each process unit in the treatment
plant until all of the target compounds'have been treated. For example, if wastewater has
semivolatile organic compounds such as pentachlorophenol, and inorganics such as chlorides,
then the pentachlorophenol could be removed in a granular organic carbon unit, while the
inorganics would pass through the unit. Then a precipitation or ion exchange unit could be
added to remove some inorganics.
Wastewater treatment plants are, therefore, comprised of a number of process units that are
sequenced to achieve the desired degree of treatment (called a flow scheme). Unit processes that
target a specific compound or group of compounds allow other nontarget compounds to pass. If
nontarget compounds interfere with a unit process, then they are removed first, or a new unit
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process is selected. Testing occurs during treatment at any POTW to ensure that the treatment
process is producing water that meets the requirements of the discharge permit.
The Metro facility has been designed to treat wastewater from the Denver Metropolitan area.
Consequently, the flow schemes employed are capable of handling a wide variety of compounds.
Wastewater sent to Metro comes from private homes, businesses, and industries throughout the
area. Wastewater from domestic sources (homes) may often contain a wide range of hazardous
chemicals, including such common household products as laundry bleach, Drano'", Tilex'",
EasyOff , and Vanish. Metro's POTW is capable of treating such chemicals if they are
present in the waste stream.
53. Does Metro have a proper facility to treat the inorganics left over after treatment? T 89
Yes, Metro meets the standards of its discharge permit with regard to treating inorganics in the
water and in the sludge.
54. Is there an agreement between Denver and Metro regarding the raw sewage that was
dumped into Lowry and what they were going to pay for that? Metro originally placed
the sewage sludge on site and now you 're going to send this waste back to Metro?
So why did the EPA, who originally called the Metro a responsible party and called the
waste from Metro hazardous, why is the EPA now condoning Metro's treatment of waste,
which could appear not to be adequate since they generated hazardous waste to begin
with. T91
Metro has been designated a PRP at the Lowry Site because of surface disposal of wastewater
sludge that occurred at the Lowry Site from 1969 through 1986. Approximately 160 acres along
the northern and eastern boundaries of Section 6 were used for surface disposal of wastewater
sludge. The sludge was applied to the surface and then incorporated into the soils. The material
that was surface disposed was sludge from the treatment process and not raw sewage or
biosolids.
Metro's responsibility at the Lowry Site'was triggered because of the location of its sludge
disposal rather than because of any inherent hazard posed by Metro's sludge. Once a problem to
be addressed under CERCLA is identified at a site, then any party that generated waste
containing any amount of hazardous substances is liable under CERCLA without any need to
prove that the waste actually caused the need for the remedy. Metro's sludge by itself would not
have required clean up at Lowry; when combined with the liquid industrial wastes containing
large amounts of hazardous substances, clean up became necessary.
The treatment process used during the time period when the sludge was applied at Lowry was
different than the process Metro currently uses. Additionally, the National Pretreatment Program
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was not in effect prior to 1986, so the wastewater coming into the Metro facility had higher levels
of contaminants than the wastewater currently accepted into the Metro facility.
EPA is recommending the POTW option because it is the most technically feasible, cost-
efficient, protective, and reliable option. Pretreated ground water from the Lowry Site would
contain only materials that Metro is already permitted to receive and is currently handling safely
and reliably. The pretreated ground water discharged to Metro would meet stringent requirements
that have been designed to assure protection of public health and the environment. The biosolids
produced by Metro have been given the highest rating under Federal and State standards and are
classified as "exceptional quality." The "exceptional quality" status of the biosolids produced by
Metro would not be affected by the Lowry water (see Executive Summary - Human Health,
Environmental, and Biosolids Concerns). These biosolids are approved for application to
farmlands and home gardens. Water discharged to the South Platte River will also be required to
meet all Federal and State standards. To be safe, the pretreated ground water from the Lowry
Site and all discharged waters will be carefully monitored to make sure that all standards are met.
55. Are you going to be monitoring the water coming out of Lowry? T 92
Yes. The pretreated ground water leaving the Lowry Site will be monitored by Metro for many
constituents. EPA and CDPHE will ensure that all parameters listed in Table 11-2 of the ROD
are monitored. The contaminated water collected at the Lowry Site will initially be tested before
entering the onsite treatment plant, will be monitored at various locations within the onsite
treatment plant, and will be monitored prior to discharge to the sewer system.
56. Is Metro going to be monitoring for chemical compounds T 92
Metro will be monitoring for chemical compounds in its effluent as required by its permits. In
addition, Metro will obtain influent information from industrial dischargers that send wastewater
to the POTW.
57. Are you going to be monitoring for plutonium? T 92
Radionuclides, including plutonium, will be monitored in the effluent from the Lowry Site.
There are performance standards in the ROD (EPA, 1994a) for gross alpha, gross beta, and a host
of radionuclides. The monitoring program will initially test for gross alpha and gross beta levels.
If these standards are determined to be exceeded, then speciation will be performed to evaluate
which radionuclide(s) is present in the sample. Speciation is the identification of specific
radionuclides contributing to the overall radioactivity within a sample.
H:\DA\WORDPWIN\IOO.WPD 56
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58. What about if the sewer backs up and the chemicals come up through people's basements
and people's yards and things like that? Are you prepared for that kind of emergency?
V 92
Although it would be unrealistic to assume that sewer lines never break or leak, the presence of
pretreated Lowry ground water in the wastewater stream within the sewer systems will pose no
additional risk to the public or the environment. First, concentrations of contaminants in the
pretreated Lowry ground water will meet Metro's pretreatment standards. Second, these
pretreatment standards for nonhousehold discharges are more protective of the environment than
are the standards for raw household sewage discharges. Third, pretreated Lowry ground water
will not increase the risks posed to the public or the environment.
59. Can you clarify the requirements of the discharge permit? Does the permit address the
plutonium problem? T 93
The discharge permit for the Lowry Site will include standards for gross alpha, gross beta, and
specific radionuclides. Discharge permits are written to establish monitoring requirements for
specific compounds at a specified frequency. The monitoring program has been established
based on many factors, including the potential to exceed a standard based on historical data.
60. Are we going to have citizen monitors there as well to monitor that everything is fair and
square? T94
There is a TAG that has been awarded to CLLEAN for this purpose.
61. It appears that EPA is trivializing the tiny amount of waste that's going into the sewer
system and, yet, what I believe the public should understand is that this proposal is for
this trickling to go on for 30 years. T 95
*
At this time, it is not possible to estimate how long the pretreated Lowry Site ground water will
continue to be treated at the Metro facility. Therefore, in order to evaluate the cost of the
proposed treatment alternatives, EPA used a 30-year time-frame. The POTW option for treating
ground water is one component of a comprehensive sitewide remedy outlined in the Lowry Site
ROD (EPA, 1994a).
As specified in Section 121(C) of CERCLA, as amended by SARA (referred to as the Superfund
Law), and Section 300.430 of the National Contingency Plan, EPA will review the sitewide
remedy at least every five years after initiation of the remedial action. The purpose of the five-
year review is to assure that the remedy continues to be protective of human health and the
environment and that all aspects of the remedy are functioning as designed.
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An additional reason for this review is to evaluate whether the cleanup standards in the ROD
remain protective or whether changes to these standards may be required. EPA will continue
these reviews until no hazardous substances, pollutants or contaminants remain at the Lowry Site
above levels that allow for unrestricted use and unlimited exposure. The actual timeframe for
treatment will depend on monitoring results.
62. Will Lowry Landfill ground water be sent to and go into Metro for 30 years? T 95
If selected, the POTW remedial option will be in operation for as long as there is contaminated
ground water being recovered at the Lowry Site. At this time, it is not possible to predict exactly
how long it will take before all the contaminated ground water at the Lowry Site is treated.
63. Why is some of the Metro effluent information confidential? T 96
None of the Metro effluent information is confidential. It is all available at the Water Quality
Control Division of CDPHE, second floor, Building B, 4300 Cherry Creek Drive South, Denver,
Colorado 80246, (303) 692-3500. For effluent (discharge) information contact Ennio Daniels at
(303) 692-3604, and for a computer printout of effluent information (a monetary charge may
apply for computer-generated printouts) contact Leslie Simpson at (303) 692-3611.
64. I just want to point out that the EPA has a pathetic record of doing enforcement on
NPDES permits in this region. You allowed Martin Marietta to dump rocket fuel into a
public water supply for many years without a cent fined against them until people were
dead. There are numerous areas at issue where the EPA has totally abandoned its
requirement under law to enforce the law. T 98
This comment refers to Martin Marietta and the Friendly Hills lawsuit. This lawsuit was brought
against Martin Marietta alleging that waters from Martin Marietta were polluting the Friendly
Hills water supply. The lawsuit was 'dismissed in 1990 because there was no link found between
Martin Marietta waters and the water supplied to the homes in the Friendly Hills community.
Metro has had an exemplary record since 1990 of meeting its discharge limits and no
enforcement action has been required to be taken against it.
With regard to the Lowry Site, EPA has faithfully and diligently implemented CERCLA, and has
consistently demonstrated an unwavering commitment to protecting human health and the
environment.
65. OCA W requested information regarding risk analyses at the Lowry Landfill Site on
November 19, 1996. Bob Hite, the [Metro] District Manager, responded that no risk
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analyses had been performed. Metro has refused to provide information about site
characterization studies. If they won't respond to OCAW, they won'( be straight with the
public. T 102
All information regarding site characterization and risk assessments is available to the public at
the EPA Superfund Records Center and the Aurora Public Library. In addition, OCAW has been
provided copies of the following documents from the City and County of Denver:
Draft Baseline Risk Assessment, Shallow Ground-Water and Subsurface Liquids and
Deep Ground-Water Operable Units (EPA, 1992a)
Baseline Risk Assessment, Landfill Solids and Landfill Gas Operable Units, Soils and
Surface Water and Sediment Operable Units (EPA, 1992c)
Draft Baseline Risk Assessment, Sitewide Risk Issues (EPA, 1993)
CERCLA Site Discharges to POTWs, Guidance Manual (EPA, 1990b)
Guidance to Protect POTW Workers from Toxic and Reactive Gases and Vapors (EPA,
1992b)
66. The polluter amnesty law in Colorado allows for secrecy regarding pollution. T 103
The polluter amnesty law in Colorado has two parts: a privilege for environmental audits; and,
immunity for certain disclosure of regulatory violations. The privilege for environmental audits
does not extend to reporting that is required by applicable law, regulation, permit, or order. The
privilege can be lost or waived in a number of ways. The immunity is only for monetary
penalties. The law does not take away the regulators' ability to issue orders, require actions or
otherwise limit their authority. Criminal immunity is not available for intentional criminal acts.
67. Metro, in 1989, had a $1 million fine for violating the Clean Water Act, which was the
largest fine ever leveled against a municipal sewage district under the act. Where is the
safety net margin there? - T 103
The monetary fine that was issued to Metro eight years ago was for a number of smaller
violations that were wrapped into a single fine. In the last seven years, Metro has only been out
of compliance once (eight minutes for a release of chlorine due to equipment malfunction).
Consequently, EPA believes that Metro has a good record of compliance and is able to safely,
reliably, and effectively treat wastewater.
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68. OCA W wants to see the worker protective studies. They haven't been shown to us if they
exist. Everybody said they exist. However we 've asked to see them, and Metro has said
they don't exist. T 103
The studies that have been done to date are available at the EPA Superfund Records Center and
the Aurora Public Library. For a listing of the studies, please see the response to comment #65.
In addition, the pretreatment standards established by Metro are protective of worker safety by
complying with the "Guidance to Protect POTW Workers from Toxic and Reactive Gases and
Vapors" (EPA, 1992b).
69. / believe that this POTW proposal is unprecedented. If this country moves toward
allowing all the Superfund wastes to go into wastewaterfacilities because it's a loophole
that allows that material to be spread across the land that othenvise would have to be
disposed at a hazardous waste site under different standards, that is something you
haven't addressed. It is a reality that Metro is under different, less strict, standards than
private industry. Refineries, chemical plants cannot spread across the land the stuff that
Metro is doing now. It's a loophole of the law. T 104
70. As far as we are concerned, this loophole is allowing some of the largest industrial
corporations in Colorado, some of the most powerful interests in Colorado, to put their
wastes in a loophole situation, and then the sludge is a solution they are going to spread
across the farmlands, put it in the South Platte, expose the workers. It's a bad idea.
T 104
The POTW proposal is not unprecedented. There are at least 32 Superfund sites in the United
States that send contaminated water to a POTW for treatment. Attachment B contains a table
showing the site name, location, date of ROD, type of liquid sent to the POTW (i.e., ground
water or leachate), contaminants of concern, and whether or not the POTW land applies its
biosolids.
t
An EPA guidance document entitled "CERCLA Site Discharges to POTWs" (EPA, 1990b) is
used when evaluating whether or not wastewater from a Superfund site may be sent to a POTW.
This guidance document is intended to ensure that, when use of a POTW is considered as a
possible cleanup option, each evaluation is performed in a consistent manner. In EPA Region 8
(Colorado, North Dakota, South Dakota, Wyoming, Utah, and Montana), there are several
Superfund sites that discharge contaminated water to a POTW, including:
Old Minot Landfill - Minot, North Dakota
Utah Power and Light - Salt Lake City, Utah
Industrial discharges to POTWs, in this case to the Metro Wastewater Reclamation District, are
allowed with pretreatment under the federal Clean Water Act, as amended, 33 U.S.C. Section
H:\DA\WORDPWIN\IOO.WPD 60
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1251 et seq. , and regulations promulgated pursuant to the Colorado Water Quality Control Act,
as amended, section 25-8-101 C.R.S., 1973, et seq. Such discharges that are in compliance with
Federal and State regulations'do not represent a "loophole" in the law. Regulation Number 63,
Pretreatment Regulations (5 CCR 1002-63), includes strict requirements for POTWs to obtain
approval for pretreatment programs. Each POTW with an approved program is required to
submit annual reports including, among other requirements, an updated list of the POTWs
industrial users with their compliance status and a summary of actions taken by the POTW to
ensure compliance with pretreatment requirements. The requirements under these regulations
allow Metro to maintain the quality of its discharge and the biosolids produced.
Metro is not under less strict discharge standards than private industry, and this proposal is not a
"loophole" in the law. All discharges to surface water in the State of Colorado are regulated
under Regulation 61 (5 CCR 1002-61), the Colorado Discharge Permit System Regulations.
Application of biosolids is regulated under Regulation No. 64 (5 CCR 1002-64), Biosolids
Regulation, and the Federal Clean Water Act (1977, as amended) Pan 503 Regulations. These
regulations contain requirements and standards that have been developed to protect human health
and the environment. The regulatory requirements are the same for industrial discharges and
POTWs alike, and do not provide special consideration or "loopholes" for any individual
discharger. Metro is held to the same standards as any industry under the Colorado Discharge
Permit System (CDPS). In fact, because of the size of Metro's discharge, it is required to
monitor more frequently for some parameters. CDPS discharge limits for Metro's effluent are
intended to be protective of the South Platte River, into which the discharge flows, and the
downstream water uses. Regulatory limits for Metro's biosolids are intended to protect public
health and the environment when the biosolids are applied as a soil amendment for crops.
The pretreated Lowry Site ground water to be discharged to the sewer system will not have the
characteristics of a hazardous waste (ignitability, corrosivity, reactivity or toxicity). The
incorporation of pretreated ground water from the Lowry Site into the wastewater stream to be
treated by Metro will have no measurable effect on Metro's discharge to the South Platte River
and will not affect the "exceptional quality" status of the biosolids produced by Metro.
71. How long has waste water been disposed of in POTWs at Superfund Sites? T 105
POTWs have been accepting wastewater from Superfund sites since before 1990. There are at
least 32 Superfund sites across the country that have been identified as sending contaminated
water to POTWs for treatment. The first EPA policy memorandum on this subject, entitled
"Discharge of Wastewater from CERCLA Sites into POTWs" (EPA, 1986), may be found in the
EPA Superfund Records Center.
An EPA guidance document, entitled "CERCLA Site Discharges to POTWs" (EPA, 1990b), is
used when evaluating whether or not wastewater from a Superfund site may be sent to a POTW.
This guidance document ensures that, when use of a POTW is considered as a possible cleanup
option, each evaluation is performed in a consistent manner. In EPA Region 8 (Colorado, North
H:\DA\WORDPWIN\IOO.WPD 61
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Dakota, South Dakota, Wyoming, Utah, and Montana), there are several Superfund sites that
discharge contaminated water to a POTW, including:
Old Minot Landfill - Minot, North Dakota
Utah Power and Light - Salt Lake City, Utah
H:\DA\WORDPWINMOO.WPD 62
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TABLE 1
CHARACTERIZATION OF SITE WASTEWATER
LOWRY LANDFILL SUPERFUND SITE
REMEDIAL DESIGN
Chemical *
Performance
Standard w
(HI/L)
PQL*
(Ml/L)
WTP
Average
Influent *
-------
TABLE 1 (Continued)
CHARACTERIZATION OF SITE WASTEWATER
LOWRY LANDFILL SUPERFUND SITE
REMEDIAL DESIGN
Chemical
Performance
Standard y
WTP
Average
PQL*' Influent"
(Mi/U WU
Early
Warning "
(W/U
North Toe
Influent "
Of/D
Tola!
Influent ^
Beozidme
Benzo(a)anthracene
Benzo(a)pyrene (PAH)
Benzyl alcohol
Bii(2-chloroethyl)cther
Carbazole
Carbofuran
Carbon Telrachloride
Chlordane
Chlorobenzene
Chloroethane (Ethyl chloride)
Chiorophenol
Datapon
DDT Metabolite (DDE)
DDT (4.4-DDT)
Di(2-ethylhexyl)adipate
Di(2-ethylhexyl)phlhalate
Di-n-Octylphthlite
Dibenzofuran
Dibromochloromethane (Trihalomethane)
Dieldrin
Dinottb
Diquat
Endothall
Endrin
Endrin Aldehyde
Ethylbenzene
Ethylenedibromide
Fluoranthene
GlyphoMle
miii
HepUehlor Epoxlde
Hexachlorobenzene
0.0002
0.10
0.20
0.03
6.10
4.00
36.00
0.30
0.03
100.00
0.20
200.00
0.10
0.10
400.00
6.00
14.00
0.002
7.00
20.00
100.00
0.20
0.20
680.00
0.05
188.00
700.00
10.00
10.00
10.00
1.00
1.00
1.00
5.00U
0.50U
0.50U
IOU
0.50U
0.50U
I.OOU
38.43
10.00
0.10
115.00
IOU
0.50U
0.50U
0.09
1.00
0.05
10.00
SOU
I5U
8.33U
7.60
0.83U
0.83U
IOU
2.75U
0.83U
0.41U
0.83U
8.56
1.70
IOU
0.08U
0.08U
0.05U
0.06U
0.83U
500U
8.33U
0.05U
O.OMI
8.33U
840U
107.5U
I07.5U
107.5U
107.5U
46.00
47.25
9.25
2.50
46.25U
0.38U
75.75
89.63
59.72
1.30U
0.08U
0.05U
0.70U
103.31
0.03U
107.5U
O.I6J
0.04U
107.5U
208U
2I.5U
2I.5U
33.5U
28.I6U
9.85
2.70
9.65U
0.40U
15.55
18.73
8.26U
0.064U
0.08U
8.33U
IOU
0.83U
0.05U
0.50U
107.5U
I07.5U
46.50
0.08U
2.5U
29.5U
29.5U
9.70
0.056U
0.9U
0.05U
O.I9U
21.06
400U
28.16U
..mm.
0.048U
28.16U
on i
mx
-------
TABLE 1 (Continued)
CHARACTERIZATION OF SITE WASTEWATER
LOWRY LANDFILL SUPERFUND SITE
REMEDIAL DESIGN
Chemical *
Performance
Standard w
(MI/L)
WTP
Average
PQLW Influent*
Qij/L)
Early
Warning "
frl/l)
North Toe
Influent"
Total
Influent *
(Mi/L)
Hexachlorobuladiene
Hexachlorocyclohexane, Gamma (Lindane)
Hexachlorocyclopentadlene
Itophorone
Meihoxychlor
Naphthalene
Nitrobenzene
Oxamyl (Vydate)
PCBi
Pentachlorobentene
Phenanthrene (total PAHt)
Picloram
Simazlne
Styrene
Toluene
Toxaphene
Trie*
Xylenei (total)
Inorganici
Aluminum
Arsenic
Afbestoi (fibert/l)
Barium
Beryllium
Boron
Chromium (af Cr VI)
1.00
0.006
0.20
50.00
1.050.00
40.00
5.00
63.00
3.50
200.00
0.005
6.00
1.00
0.0031
300.00
500.00
4.00
100.00
5.00
1.000.00
0.03
5.00
2.00
10.000.00
5.000.00
6.00
50.00
30.000.00
1.000.00
4.00
750.00
5.00
250,000.00
50.00
10.00
0.05
2.0U
10.00
1.00
10.00
50.00
5.00
5.0U
56.54
0.30U
33.86
1.25
0.92
46.96
IOU
5U
28.14
I.OU
5.0U
862.500.00
200U
7.50U
0.05U
0.05U
IOU
6.67U
0.08U
53.20
6.37
7.33U
2.80U
0.41U
IOU
28.33U
8.33U
5.0U
1.50U
91.95
0.83U
0.40U
75.60
107.74
I.OU
28. IU
2.75
5.78
544.28
1.44
4.79
977.500.00
0.05U
107.5U
0.061
0.24
I07.5U
107.5U
0.38U
375.941
107.75
107.5U
I.OU
0.38U
828.50
I07.5U
2,934.13
46.25U
84.23
1.303.60
.75U
133.50
89.25
516.75
3.509.82
4.43
653.87
2T3U
0.09
29.5U
26.84U
O.I4U
26.65
27.36U
2.44U
0.40U
8.0U
13.25U
260.96
0.47U
4.122,0
724.48
1.69
130.77
160U
IHI/71747»/3».XLS
-------
TABLE 1 (Continued)
CHARACTERIZATION OF SITE WASTEWATER
LOWRY LANDFILL SUPERFUND SITE
REMEDIAL DESIGN
Chemical rf
Performance
Standard w
0-l/L)
WTP
Average
Influent *
Early
Warning
North Too
Influent"
(MI/U
Total
Influent
(Mi/U
Chromium (total)
Cobalt
CoHform (total)/100 ml
Color, color units
Copper
Corrosivity
Cyanide
Fluoride
Foaming Agents
Orcis Alpha (pCi/l)
dross Beta (pCi/l)
Nitrate & Nitrite as N
Nitrite as N
pH
Thallium
Vanadium
Zinc
50.00
50.00
1.00
15.00
200.00
non-corrosive
200.00
2,000.00
500.00
15.00
150.00
300.00
15.00
50.00
2.00
100.00
10,000.00
10,000.00
1,000.00
6.5 to 8.5
10.00
50.00
250,000.00
2.00
100.00
2.000.00
5.0U
5.0U
8.88
0.50U
31.90
26.59
16.80
30U
36.06
29.35
55.000.00
7.55
32.47
4.0U
576,000.00
3.0U
110.35
84.07
24.01
11.97
20.00
4,350.00
51.81
44.47
30.543.67
23.88
6.854.67
0.11
306.13
2.810.00
90.03
6.92
4.20
5.0U
1,752,500.00
400U
44.87
102.20
11.97
29.97
45.28
26.20
1,306.67
6.39
9.99
16.16
21.24
261.73
" Compounds listed in Table 11-2 of Record of Decision (ROD), from the August 1995 Explanation of Significant Differences (ESD).
" ROD Table 11-2 performance standards (from ESD).
a PQL - Practical quantitalion limit (from ESD).
* Average of data from sample port SP-01 at onsite water treatment plant.
*' Average of data from early warning monitoring wells A-l 15, MPZ-I, and MW-EW-I.
" Average of data from north toe monitoring wells A-105, GW-111, OW-112, and U-712.
** Data calculated using average water treatment plant influent at 8 gpm, and average north toe influent at 2 gpm; early warning data were used if data were not
available at SP-01.
|,\' A'! >'-.-'] Shading indicates concentration of total influent in exceedance of ROD performance standards.
-------
Hazardo is Matt rials
-------
Response to Type A Letters
Commenters who signed these letters state that they do not want Lowry Landfill
Superfund waste added to Metro sludge, do not want ptutonium in their food, air
and water, and do not want future generations contaminated by this.
The ground water from the Lowry Site would be pretreated to meet Federal and State standards.
These standards are safe and designed to protect public health and the environment.
There is no evidence to indicate that plutonium was dumped at the Lowry Site. EPA has a
responsibility to protect human health and the environment. Even though radionuclide
contamination does not appear to be evident, there is an onsite early-warning ground-water
monitoring system currently in operation. This system has been designed to alert EPA and
CDPHE if unacceptable levels of radionuclides appear in the ground water. If this scenario were
to occur, Lowry Site water will not be sent offsite until the levels of radioactive contaminants
were reduced to ROD performance standards or pretreatment standards.
Response to Ward Hollingsworth's Comments
on the Type A Letter
This stuff not only affects us, but our livestock, deer, antelope, fish, and other
wildlife. I don't know about anybody else but there (is) a good share of us that
live out here that like to hunt and fish and I don't want that heritage gone forever!
People depend on the land to survive so don't screw it up.
The treated sludge from Metro (called biosolids) will be analyzed to make sure it continues to
meet all necessary Federal and State standards. (See Executive Summary - Human Health,
Environmental, and Biosolids Concerns.) These standards are designed to protect human health
and the environment, including wildlife. Based on available research, EPA and CDPHE expect
to see no harmful effects on area wildlife and see no reason to expect any change in local hunting
and fishing activities as a result of this ppposal.
Response to Diane Lee's Comments Included on the Type A Letter
This is an outrage and I will be protesting loud and long. I refuse to have our
area turned into another Love Canal. This is not wanted in our neighborhood. If
there is no threat to our health, leave it in Aurora we do not want it out here.
The proposal to send pretreated ground water from the Lowry Site to Metro is designed to clean
up a Superfund site, not create a new Superfund site. The material from the Lowry Site, after
pretreatment onsite and then additional treatment at Metro, will meet Federal and State standards
and will pose no threat either to human health or the environment. Metro provides fertilizer to
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people and organizations throughout the Denver metropolitan area for use on home gardens,
parks, and golf courses. (See Executive Summary - Human Health, Environmental, and Biosolids
Concerns.)
Response to Kent Lee's Comments Included on the Type A Letter
We have every- intention of using whatever means necessary? to protect our
community from possible risk regardless of the government's assertion that all
solid waste is safe. We don't trust you or our government to protect our interests.
As a POTW, Metro is designed and equipped to safely and reliably handle wastewater from
industry, cities, and households, treating and/or removing the harmful materials present in
wastewater. Biosolids, which are a byproduct of the wastewater treatment process, can be used
beneficially as fertilizer. In addition to numerous government studies, industry and academic
research has shown the benefits of applying biosolids as fertilizer and reducing the ever-
increasing pressure on our nation's landfills. (See Executive Summary - Human Health,
Environmental, and Biosolids Concerns.)
Response to Joseph O'Brien's Comments
Included on the Type A Letter
I do not feel that sludge should be dumped on any ground as there are other
alternatives though costly in monetary standards, but less costly in long-term
health for ourselves and the land we ask to feed and support us.
The comment is noted. All ground water collected at the Lowry Site will be pretreated prior to
discharge to the sewer system. Concentrations of inorganic chemicals in the pretreated Lowry
Site ground water will be lower than the concentrations in typical industrial discharges.
The quantity of Lowry Site inorganic'chemicals that may accumulate in the sewage sludge (or
biosolids) will not affect the "exceptional quality" status of Metro's treated sludge, or biosolids
(See Executive Summary - Human Health, Environmental, and Biosolids Concerns). EPA
recognizes that the commenter may ha've serious reservations about using sewage sludge as a
fertilizer. This is an important issue that continues to foster lively debate. EPA intends to
carefully collect and evaluate evidence relating to Metro's ongoing biosolids land application
activities.
H:\DAWORDPWINMOO.WPD 70
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Response to Charles Vest's Comments
Included on the Type A Letter
/ do not understand why the EPA would authorize adding as much as 39 parts per
million of plutoniurn or toxic chemicals when several foreign nations allow much
less, one as low as I part per million or less according to CNN news broadcast. I
am also very concerned about the possibility of this sludge especially with this
plutoniurn and toxic chemicals being added polluting our underground water
which sen;es the communities ofWatkins, Bennett, Strasburg, Byer, Deer Trail
and Agate and also what it may do to much of northeastern Colorado and the
state of Nebraska when it is channeled into the Plane River which flows through
northeastern Colorado and the State of Nebraska.
Please refer to "A Guide to the Biosolids Risk Assessments for the EPA Part 503 Rule" (EPA,
1995). This EPA document discusses the differences between chemical standards in the United
States and standards from other countries and describes why the differences exist (e.g., dietary
reasons, differences in soil types, differences in crop types, etc.).
Before proposing the POTW option, EPA and CDPHE evaluated the available research and
scientific data on this subject and concluded that pretreatment of the Lowry ground water onsite
with additional treatment at Metro's POTW was the best of the available options. EPA and
CDPHE believe Metro and Aurora can safely, reliably, and effectively treat the ground water to
meet Federal and State standards.
As part of the Lowry Site cleanup project, EPA and CDPHE conducted detailed reviews of all
information available on the wastes disposed at the Lowry Site. No plutoniurn or other toxic
chemicals from the Lowry Site will be added .to the waste stream at the Metro and Aurora
POTWs. To be extra safe, EPA and CDPHE will monitor the water leaving the Lowry Site using
an "early warning system." This system will alert EPA and CDPHE Site managers to unusual
levels of constituents in the wastewater, allowing them to remove and/or treat these materials as
necessary to continue to protect human health and the environment.
i
Metro and Aurora will be required to meet the standards set out in its discharge permit. This
permit requires the discharge to be protective of downstream uses of the water, including those in
northeastern Colorado and the State of Nebraska. Any biosolids that are applied to lands near
Deer Trail will be required to continue to meet EPA's "exceptional quality" criteria, and,
therefore, will not pollute underground water.
Response to John Vest's Comments Included on the Type A Letter
/ received a reply letter from your office of the E.P.A. in Denver in regards to my
first letter. It escapes my comprehension how the E.P.A. can ever consider such a
project as this. I remember when Lowry landfill was closed down. It was
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considered one of the worst toxic and radioactive contaminated sights in the
Nation. Now all of a sudden the contaminated water is considered by the E.P.A.
as being completely safe to send through a sewer plant instead of a toxic waste
plant and the sludge dumped at Deer Trail and the water dumped into the Plane
river. Which in time could and would pollute our water supply at Deer Trail as
well as Byers, Strasburg and Bennett. Also the water dumped in the Platte would
effect a good portion of Northeastern Colorado and Nebraska. Common sense
tells me or anyone else for that matter, it should stay where its at.
Ground water from the Lowry Site will be pretreated onsite to remove contaminants in order to
meet pretreatment standards before it is sent to the POTWs for further treatment. After onsite
treatment, the water that will be discharged to the sewer system will not have any of the
characteristics of a hazardous waste (ignitability, corrosivity, reactivity or toxicity). It will be
sent to the wastewater treatment plants to remove any remaining pollutants to meet Federal and
State water quality standards. These water quality standards, and the standards for biosolids
application, are designed to protect public health and the environment. EPA and CDPHE
regulate the POTWs to ensure that the effluent meets the water quality standards before being
discharged and to ensure that biosolids meet regulatory standards before they are applied to
farmland as a fertilizer. Mixing the pretreated Lowry Site ground water with the wastewater
stream treated by Metro and Aurora will have no measurable effect on either Metro's discharge
to the South Platte River or Aurora's discharge to Sand Creek. In addition, the "exceptional
quality" status of Metro's biosolids will not be affected (sludge produced at the Aurora POTW is
piped to Metro for further treatment).
Response to the Type B Letters
Commenters who signed these letters are opposed to adding Lowry Site
wastewater to Metrogro sludge coming out to Elbert and Arapahoe Counties.
Commenters state there is no plant that can remove the radioactive materials
from the water. Commenters also state that the 30-year plan will add tons of
sludge daily on wheat fields owned by Metro, and create a build-up of chemicals
that will never go away. Commenters note that Metro owns land around the
headwaters of the Foxhill Aquifer and above live water that recharges the Foxhill
Aquifer. Commenters believe that the live water has already been contaminated
by sludge-fertilized debris and note that the aquifer serves the towns of Deer Trail
and Byers and hundreds of farms and ranches.
The comment is noted.
EPA and CDPHE agree that wastewater treatment plants are neither equipped nor designed to
remove radioactive materials from wastewater. Therefore, EPA and CDPHE will work to ensure
that no radioactive materials are sent to the wastewater treatment plants for removal. Historical
records and extensive Site sampling show that no appreciable levels of radioactive materials have
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been detected in Lowry Site ground water. Nevertheless, EPA and CDPHE are requiring the
responsible parties to operate an "early warning system." This system has been designed to alert
EPA and CDPHE if unacceptable levels of radionuclides appear in the ground water. If this
scenario were to occur, Lowry Site water would not be sent offsite until the levels of radioactive
contaminants were reduced to ROD performance standards or pretreatment standards.
EPA and CDPHE use "30 years" for planning purposes and for cost-comparisons. At this time, it
is not possible to predict exactly how long it will take before all the contaminated ground water
at the Lowry Site is treated. The additional amount of biosolids resulting from the pretreated
Lowry Site ground water sent to the POTWs for further treatment is quite small. The biosolids
will be applied according to strict Federal and State standards. These standards are designed to
make sure that biosolids are indeed, safe, for both people and the land. The biosolids currently
produced and applied by Metro are of high quality. EPA and CDPHE will carefully monitor to
ensure that human health and the environment continue to be protected.
Response to Harvey Crandell's Comments Included
on the Type B Letter
The commenter asks, "Do you want to eat the organic foods from this sludge
soil?"
Numerous studies conducted by the government, private industry, and universities show that land
application of treated sewage sludge (biosolids) is safe and beneficial. Federal and State
standards ensure that food is only grown on those biosolids that meet the strictest criteria.
Metro's biosolids consistently receive high ratings.
Response to Clara and Harold Hanks' Comments
Included on the Type B Letter
j
Our land that will be affected by this Lowry Landfill waste water added to
Metrogro sludge is in third generation ownership and we certainly protest this
addition of highly contaminated waste water being added to Metrogro sludge. We
would like to see a safer environment for our children, grandchildren, and great-
grandchildren.
With the addition of pretreated ground water from the Lowry Site, there will be no
distinguishable change in the quality of the biosolids produced by Metro (See Executive
Summary - Human Health, Environmental, and Biosolids Concerns). EPA and CDPHE take
their responsibility to protect human health and the environment very seriously. We have
carefully evaluated all the options for safely and effectively treating ground water from the
Lowry Site. The current proposal is safe, reliable, and cost-effective. EPA and CDPHE believe
this option will protect the health of this generation, as well as future generations.
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Response to Shirley A. Pisel's Comments
Included on the Type B Letter
/ think it is criminal to have this foisted on us out here. It is bad enough that we
have to have the sludge out here. Apparently there is no concern for people out
here. We are just a lesser part of your concern.
Please see the response to Mr. and Mrs. Hanks' letter. Now, as always, EPA and CDPHE are
available to meet or speak with anyone from the concerned community.
Response to Evelyn Stewart's Comments
Included on the Type B Letter
Residents in this Arapahoe County area do not want this waste dumped here.
The comment is noted.
Biosolids are not considered "waste." Biosolids' application to farmland is not considered
"dumping." Biosolids are applied only at a rate that will sustain crop growth, and are used as a
beneficial alternative to other types of fertilizer. (See Executive Summary - Human Health, :
Environmental, and Biosolids Concerns.)
Response to the Type C Letter
After looking at a lot of information concerning whether the Metro Wastewater
Reclamation District should treat the pretreated groundwater from the Lowry
Landfill Superfund Site, I believe you should decide to let the Metro District do it.
The Metro District treatment solution looks like it is the best solution from both
an environmental and an economic point of view.
The comment is noted.
Response to Type C Letter for the
Former Tire Pile Area and the Water Treatment Plant
We are submitting the following comments regarding the proposed Second ESD to
the Lowry Landfill Record of Decision. We support the proposed onsite treatment
and disposal of the former tire pile materials. We support the proposed POTW
option. In light of the new information from recent investigations and proposed
changes to the selected remedy, we believe that the remedy remains protective of
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human health and the environment, complies with applicable or relevant and
appropriate requirements, and is cost-effective. We support the proposed Second
ESD.
The comment is noted.
Response to Adrienne Anderson's
June 30,1997 Letter
/. The Lowry Superfund site groundwater is mixed waste, contaminated with both
hazardous and radioactive wastes. The EPA region VIII Office, while it is fully aware of
these facts, has opted to ignore them.
The Lowry Site ground water that would be extracted and treated is not a mixed waste. To be
considered a mixed waste, a waste must contain both "radioactive waste," as defined in 10 CFR
61, and "hazardous waste," as defined in 40 CFR 261. Water that will be discharged to the
sanitary sewer system under the current proposal is neither radioactive nor hazardous. Data
collected from ground-water monitoring wells in the area from which ground water is to be
extracted show that concentrations of radionuclides are below performance standards for the
Lowry Site and within measured background concentrations. Ground-water monitoring will
continue to identify any changes in water quality that would necessitate modification of the
treatment process.
2. A large volume of contaminants identified at the Lowry Superfund Site have no
regulatory standards set for them. While EPA Region VIII office is fully aware of these
facts, it has opted to ignore them.
There are 58 ground-water chemicals'of concern identified in the ROD (EPA, 1994a). Cleanup,
or performance, standards were established in the ROD based on applicable or relevant and
appropriate requirements (ARARs) for the chemicals of concern as required in EPA's guidance
document "CERCLA Compliance with Other Laws" (EPA, 1988a). If there was more than one
standard for a particular chemical, then the lowest (most protective) standard was used as the
performance standard. For the remaining chemicals of concern that did not have an established
standard, other sources, such as proposed standards or guidance, were used to establish the
performance standard. In addition, risk-based criteria based on calculations using carcinogenic
or non-carcinogenic ingestion doses were used. There are seven chemicals of concern that do not
have performance standards in the ROD. These chemicals of concern will be assessed during
EPA's 5-year review and if any new regulations, guidance, or risk-based criteria are then
available, performance standards will be established.
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3. The EPA Region VIII Office has failed to consider the additive, cumulative and
synergistic effects of the combined load of contaminants already known to be present.
Additive, or cumulative, risk is calculated and presented in the Lowry Site Baseline Risk
Assessment documents (EPA, 1992a; EPA, 1992c; EPA, 1993). Uncertainties such as
synergistic effects, which are pan of the risk assessment process, are discussed in those
documents. The purpose of a baseline risk assessment is to estimate potential health risks if a
site is not cleaned up. Information produced in the risk assessment is used to make decisions
about remediation alternatives and cleanup requirements. The risk assessment process is .
outlined in EPA guidance documents and publications of the National Academy of Sciences. It
provides a consistent basis for documenting public health threats and evaluating risks at different
sites.
More detailed information on the risk assessment process as followed for the Lowry Site can be
found in:
Baseline Risk Assessment Shallow Ground-Water and Subsurface Liquids and Deep
Ground-Water Operable Units (EPA, 1992a)
Baseline Risk Assessment Landfill Solids and Landfill Gas Operable Units, Soils and
Surface Water and Sediment Operable Units (EPA, 1992c)
Draft Baseline Risk Assessment Sitewide Risk Issues (EPA, 1993)
4. The EPA Region VIII Office is fully aware of the fact that land on, contiguous to, and in
the immediate vicinity of the Lowry Landfill site (as its boundaries have been defined by
EPA Region VIII) was used as a dumping area for hazardous and/or radioactive wastes
prior to the time the federal government transferred title to the City and County of
Denver in 1964 for use as a municipal trash dump, yet has opted to ignore these facts of
record.
i
The Lowry Site is located in the southwest corner of the Bombing Range (see Figure 1). There is
no evidence that the land on, contiguous to, or in the immediate vicinity of, the Lowry Site was
used as a dumping area for hazardous and/or radioactive wastes prior to 1964. The history of the
Lowry Site is documented in the ROD and in documents prepared as part of the investigations for
the Lowry Bombing Range:
Master Work Plan, Engineering Evaluation/Cost Analysis, Former Buckley Field (Lowry
Bombing and Gunnery Range), Aurora, Colorado (COE, 1997)
Archives Search Report, Findings, Buckley Field, Arapahoe County, Colorado (COE,
1995)
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In addition, Lowry Site remedial investigations document the fact that EPA and CDPHE were
aware of the proximity of the Lowry Bombing and Gunnery Range and considered those issues
during the remedy selection process. EPA and CDPHE found no evidence (records or analytical
confirmation) that hazardous or radioactive wastes related to the Lowry Bombing and Gunnery
Range were ever used or disposed at or near the Lowry Site. No unexploded ordnance, or any
other wastes indicative of military activity, have been found at the Lowry Site.
5. The EPA Region VIII Office is fully aware that the area surrounding the Lowry Landfill
on the south and east was declared by the federal government's U.S. Army Corps of
Engineers in 1995 as a "Probable Catastrophic Risk Zone, " due to unexploded
ordnance, napalm bomb drops by the Rocky Mountain Arsenal, reported chemical
weapons testing and other hazards, yet has used this area to define "background" levels
for comparison to contaminant levels inside the presently-defined boundaries for the
Superfund site.
The "Probable Catastrophic Risk Zone" referred to in the comment is located within the Lowry
Bombing and Gunnery Range (Bombing Range) property, but is east of the Lowry Site (see
Figure 1). The area immediately south of the Lowry Site is where many of the background
samples were taken and is outside the boundaries of the Bombing Range. In any event, the
catastrophic risk designation pertains to the potential for ordnance to explode and does not have
any bearing on ground-water monitoring activities.
Background wells were identified through a careful and detailed process that included an
awareness of the location of the bombing range in relation to the Lowry Site. Statistical analyses
were used to evaluate the analytical results from the background wells. The purpose of collecting
samples from these wells was to evaluate the background concentrations of naturally-occurring
inorganic constituents only.
In 1994, the Respondents to the RD/RA Order installed new wells along the western and
southern Lowry Site boundaries. These wells are not located on the Bombing Range, have been
monitored on a quarterly basis since installation, and have shown similar background
concentration results to those wells located at the southern boundary of the Lowry Site. In
addition, no ordnance (e.g., bombs) were encountered during din-moving activities performed in
connection with landfilling operations.
6. Within the area EPA Region VIII has considered as "background" for Lowry
Landfillboth within and just outside thefenceline of the siteare numerous other
upgradient sources of contamination, which have been inadequately investigated or
completely ignored by EPA Region VIII to date: a) former Titan Missile silos, where
Martin/USAF housed nuclear warhead intercontinental ballistic missiles in the early
60's, including the 1A Titan silo immediately to the east of the Landfill; b) roads
bordering the Lowry Landfill, including Gun Club Road on the east and Quincy on the
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south, where credible and corroborated eyewitnesses have reported "hundreds" of
incidents of indiscriminate dumping of liquid hazardous and/or radioactive wastes by
tanker trucks hauling loads to the Lowry Bombing Range and Landfill area.
EPA disagrees that the background samples were taken in areas known to have upgradient
sources of contamination.
a. The closest former Titan missile site is more than 1/2 mile east of the site (not
upgradient).
b. The report of a single eyewitness of indiscriminate dumping could not be corroborated
nor confirmed with sampling. (See response to No. 6 in the transcript or No. 7 below.)
7. / personally accompanied one such eye witness, retired Colorado State Highway
Patrolman William H. Wilson, in February 1990 to the site of such incidents, which he
had reported both at the time in the early 60's, and again the 70's and 80's, to various
state and federal authorities; including the EPA; c) a former military munitions dump; e)
a former military demolition range where several unexploded bombs and other debris
have been found in the last year alone by federal officials; and d) other known sources of
contamination at the southeastern corner of the Lowry Landfill which EPA Region VIII
has completely failed, to date, to examine as contributing sources to Lowry Landfill's
extensively contaminated radioactive and hazardous groundwater and other
environmental media.
EPA conducted field investigations that included soil sampling in the areas of alleged dumping.
Results from background soil samples along Quincy Avenue show no evidence of surface-
exposed or buried bombs or radioactive materials. EPA has no evidence that plutonium or other
man-made radionuclides are present in the Site ground water above background levels.
The former highway patrolman's 1977 report of alleged dumping of materials in 1960 and 1961
could not be corroborated by any other witness or by any sampling and analysis. EPA
interviewed the former highway patrolman and conducted extensive Site-related research. Based
on the accumulated body of information in the Administrative Record, the former highway
patrolman's story appears to have no impact on the Lowry Site project.
8. EPA Region VIH's failure to collect adequate funds for remediation and clean-up from
the Department of Defense, Department of Energy and its various contractors in the
region, for military-related waste dumping in, around and near the Lowry Landfill site,
and inappropriately negotiating sweetheart-deal "de minimis " settlements without local
notice to potentially affected citizens, blatantly ignoring clear grounds upon which such
settlements should not even been considered.
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The Respondents who are cleaning up the Site under the RD/RA Order are also paying for that
cleanup.
The de minimis settlements are not "sweetheart deals." Before entering into any de minimis
settlement related to the Lowry Site, EPA: a) evaluated the eligibility of each PRP within the
context of qualifying criteria established in a protocols document; and b) made all proposed
settlements available for public review and comment. The de minimis protocols document itself
was made available for public review before it was finalized for use.
9. EPA Region VIII's apparent failure, to date, to even contact or adequately consider
significant "potentially liable parties" such as Dow Chemical, in its capacity as a former
operator at Rocky Flats, with known and/or alleged dumping activities at and near the
Lowry Bombing Range and Landfill, and possible other former Atomic Energy
Commission contractor(s) and/or agent(s) acting in their behalf.
Dow Chemical was, in fact, issued a CERCLA 104(e) information request. Dow Chemical
provided EPA with a detailed response regarding waste disposal at the Lowry Site. Records
indicate that, in its capacity as an operator at the Rocky Flats Plant, Dow Chemical did not
arrange to have any waste disposed at the Lowry Site.
JO. EPA Region VIII's stunning and astounding attempts to distort, deny, mislead an/or fail
to acknowledge key information related to all of the above, in statements made to the
public, local governmental officials, the local, national and international media, and
others, all of which warrants investigation by proper oversight authorities, based upon
extensive review of the Administrative Record of the Lowry Landfill Superfund Site.
The Administrative Record is the basis upon which EPA issued the March 10, 1994 ROD (EPA,
I994a) and the First and Second ESDs. Documents contained in the Administrative Record are
available for public review. EPA is always willing to meet with any concerned citizen who
might wish to leam more about a particular site-specific matter. Given that EPA was not
provided any substantive evidence to support the above allegations, EPA can not assume
responsibility for misinterpretations of information contained within the Administrative Record.
Response to E. Jordan Asnicar's
June 27,1997 Letter
Another Love Canal Tragedy? Why flush toxic residues dumped at Lowry
Landfill into the public sewer?
The POTW option does not involve flushing toxic residues into the sewer. All ground water
collected at the Lowry Site will be pretreated prior to discharge to the sewer system.
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Concentrations of inorganic chemicals within the pretreated Lowry Site ground water will be
lower than for typical industrial discharges.
These toxic residues contain industrial pollutants, spent rocket fuel and even some
plutonium.
There is no historical or sampling evidence of plutonium or spent rocket fuel contamination at
the Lowry Site. EPA has no evidence that plutonium or other man-made radionuclides are
present in the Site ground water above background levels. Even though radionuclide
contamination does not appear to be evident, there is an onsite early-warning ground-water
monitoring system currently in operation. This system has been designed to alert EPA and
CDPHE if unacceptable levels of radionuclides appear in the ground water. If this scenario were
to occur, Lowry Site water would not be sent offsite until the levels of radioactive contaminants
were reduced to ROD performance standards or pretreatment standards.
Once these pollutants enter a public sewer, the corporations who used Lowry as a dump
have no further responsibility or liability.
Under the Superfund law, the liability of any responsible party is not affected by the method of
cleanup selected by EPA.
Response to Daniel L. Brotzman's/City Attorney, City of Englewood
March 31,1997 Letter
and Andrew C. McMinimee's/City Manager, City of Littleton
April 2,1997 Letter
The City supports the proposed changes to the ROD as set forth in the
Explanation of Significant Differences (March 1997) and urges the adoption of
those changes. i
The comment is noted.
Response to Donn L. CalkinsYGablehouse & Epel
May 12,1997 Letter
Gablehouse & Epel represents Cummins Power, Inc., in matters relating to the
Lowry Landfill Superfund Site. Cummins has reviewed the proposals put forth in
the Second ESD and believes that the remedy remains protective of human health
and the environment, complies with applicable or relevant and appropriate
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requirements, and is cost-effective. Cummins supports the proposed changes to
the ROD contained in the Second ESD.
The comment is noted.
Response to Wil Chase's/President, 1-70 Corridor Chamber of Commerce
May 21,1997 Letter
In response to the proposed "Lowry Landfill Superfund Site Second Explanation
of Significant Differences for the Record of Decision " we, as community business
members, landowners, and rural residents, request that the public comment
period be extended 60 days from May 22, 1997 to end on July 22, 1997, so that
we can review the information provided to us in the libraries. We have not had
sufficient time to get access to this information, and send our comments to you on
this subject.
In response to requests from the public, EPA extended the public comment period from April 22
through May 22, 1997. The public comment period was further extended through June 30, 1997
to allow the public additional time to review Site information (including new information
regarding treatment of a portion of the water from the Lowry Site in Aurora's POTW). With
these extensions, the public comment period on the Second ESD extended more than 90 days.
Response to Anne Culver's
May 20,1997 Letter
/ strongly protest your idea to allow the addition of Lowry Landfill waste to
Metrogro sludge being dumped in Arapahoe and Elbert Counties. I feel this
sludge will further contaminate the water supply via the Foxhill Aquifer and
should not be allowed. \
The comment is noted. All ground water collected at the Lowry Site will be pretreated prior to
discharge to the sewer system. Concentrations of inorganic chemicals within the Lowry Site
ground water will be lower than for typical industrial discharges.
The quantity of Lowry Site inorganic chemicals that may accumulate in the sewage sludge (or
biosolids) will not affect the "exceptional quality" status of Metro's treated sludge, or biosolids
(See Executive Summary - Human Health, Environmental, and Biosolids Concerns). EPA
recognizes that the commenter may have serious reservations about using sewage sludge as a
fertilizer. This is an important issue that continues to foster lively debate. EPA intends to
carefully collect and evaluate evidence relating to Metro's ongoing biosolids' land application
activities.
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Response to Frank and Patty Doyle's June 27,1997 Letter
As concerned citizens along the 1-70 corridor east of Aurora, we ask that you take
into consideration the possibility of contaminated SLUDGE being distributed in
our area on our farm lands. We ask that you follow OSHA regulations as we have
to in our health industry and that contaminants be placed in their proper
containers and taken to the proper authorities.
Metro applies biosolids as fertilizer on land owned by Metro and on land where farmers have
requested and paid for the biosolids. Biosolids are produced when sludge from a municipal
wastewater treatment plant is treated to meet regulatory standards. The biosolids will meet all
requirements for contaminants specified in the regulations (40 CFR Part 503). It is important to
note that biosolids are regulated more than any other fertilizer that is used on farmland -- many
fertilizers are not regulated at.all. Metro will be required to sample the biosolids to ensure that
they continue to meet the requirements specified in the regulations.
OSHA regulations are followed in all instances where they are applicable. However, OSHA does
not apply to municipal or State workers, including Metro workers. Metro workers are covered by
Metro's health and safety program, which includes a Chemical Hygiene Plan (Metro, 1997a).
EPA has reviewed the Plan and found it to be as comprehensive as that required in other
industries.
By sending pretreated ground water to Metro for further treatment, the contaminants will be
properly managed.
Responses to Joseph Drexler's/OCAW, Special Projects Director
June 29,1997 Letter
/. The first document, which is attached, consists of a December 13. 1991 letter authored by
John D. Faught of the Lowry Coalition of which MWRD was a member at the time the
letter was written. Accompanying Mr. Faught's letter was a copy of an evaluation of
radioactive wastes at the Lowry Landfill prepared by Harding Lawson Associates, and a
letter written by William Wilson on the illegal dumping of radioactive waste from Rocky
Flats at the Lowry Landfill. The assertions made in Mr. Faught's letter and in the
documents which accompanied the letter include:
(I) significant quantities of man-made radionuclides from the Rocky Flats nuclear
weapons facility are present at the Lowry Landfill;
(2) there is evidence of illegal disposal of radioactive material from Rocky Flats at
the Lowry Landfill;
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f3) levels ofAmericium 241 and Plutonium 239/240 detected in wells at the Lowry
Landfill are 10 to 10,000 times greater than background levels reported for Rocky
Flats by EG&G;
(4) the owners and operators of Rocky Flats have significant liability for the dumping
at the Lowry Landfill;
(5) any treatment alternatives will result in the generation of hazardous residuals,
some of which may contain concentrated levels ofradionuclides.
The assertions contained in these documents support OCAWconcerns over the existence
of significant and dangerous quantities of man-made radionuclides at the Lowry Landfill.
Please answer in writing each of these allegations noted above. In addition, please
provide copies of any and all EPA correspondence pertaining to the aforementioned
letter from John Faught and all of the assertions therein. OCA W has so far been unable
to locate a detailed trail of correspondence from EPA pertaining to the assertions raised
in Mr. Faught's letter. We find this highly unusual since the assertions made in Mr.
Faught's letter were very serious, especially coming from PRPs. Please provide copies
of any and all studies conducted to specifically answer of refute the assertions made by
John Faught and the Lowry Coalition.
The assertions contained in the above-referenced documents were not adequately substantiated
by the Lowry Coalition (Coalition). The Harding Lawson Associates (HLA) memorandum was
prepared at the request of the Coalition and was not a part of the remedial investigation process.
At the time, EPA did not respond to the 1991 Faught letter because legitimate site evaluations
were ongoing. Allegations presented in the 1991 Faught letter were based on an incomplete
analysis that did not apply accepted data evaluation techniques. The commenter is reminded that
the 1991 HLA memorandum was developed without oversight or review by the EPA and
CDPHE.
Evaluations performed subsequent to 1991 have provided a clearer understanding with regard to
the presence of radionuclides at Lowry. These evaluations were conducted in accordance with
EPA-approved protocols and properly analyzed qualified and coded data, analytical methods,
quantitation limits, temporal and spatial data relationships, as well as blank and background data.
For a further discussion ofradionuclides, the commenter may wish to read the following
documents:
Remedial Investigation Report, Lowry Landfill: Shallow Ground-Water and Subsurface
Liquids, and Deep Ground-Water Operable Units Remedial Investigation and Feasibility
Study. Arapahoe County, Colorado, as amended (HLA, 1992a)
Evaluation of the Data Quality and Occurrences of Transuranic Radionuclides in the
Shallow Groundwater and Subsurface Liquids and Deep Groundwater Operable Units
Lowry Landfill Arapahoe County, Colorado (HLA, 1992b)
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Draft Baseline Risk Assessment, Sitewide Risk Issues, Lowry Landfill, Volume 2C
(EPA, 1993).
Each assertion from Mr. Faught's letter, and the documents accompanying that letter, is
responded to below:
(1) There is no evidence to substantiate the claim that man-made radionuclides from the
Rocky Flats nuclear weapons facility are present at the Lowry Site as a result of waste
disposal activities. The Rocky Flats facility separated trarisuranic waste (waste with man-
made radionuclides) from other industrial waste and disposed of the radioactive waste at
authorized facilities in Nevada and Idaho.
(2). There is no evidence of illegal disposal of radioactive material from Rocky Flats at the
Lowry Site. Despite extensive investigation of Mr. Wilson's allegations (which included
collecting ground-water and soil samples and interviewing Mr. Wilson), EPA and
CDPHE were unable to confirm that radioactive material from Rocky Flats was disposed
at the Lowry Site.
(3) Levels of americium-241 and plutonium-239/240 were incorrectly compared to
background levels reported for Rocky Flats. In an analysis performed by Doty and
Associates, entitled "Response to Question 10, CERCLA 104(e) Information Request of
April 23, 1992 for Lowry Landfill Superfund Site" (DOE, 1992), it is stated that "In the
December 1991 report, HLA flagrantly and incorrectly ignores minimum detection levels
(MDLs) and counting errors for the Lowry Landfill data when it compares water
transuranic concentration ranges between the Lowry Landfill and the RFP facilities."
This report goes on to state that it was inappropriate of HLA to conclude that levels of
americium-241 and plutonium-239/240 detected at the Lowry Site are 10 to 10,000 times
greater than background levels reported for Rocky Flats by EG&G.
(4) Liability of the owners and operators of Rocky Flats is described in a Lowry Site de
minimis settlement, which is available for public review.
t
(5) Treatment residuals will neither result in the generation of hazardous residuals nor
contain concentrated levels of radionuclides. EPA will require monitoring of the
pretreated water to be piped to Metro using an onsite early-warning ground-water
monitoring system This system has been designed to alert EPA and CDPHE if
unacceptable levels of radionuclides appear in the ground water. If this scenario were to
occur, Lowry Site water would not be sent offsite until the levels of radioactive
contaminants were reduced to ROD performance standards or pretreatment standards.
2. Since these assertions concerning the existence of significant quantities of radioactive
waste at the Lowry Landfill were made by entities who comprise the Lowry Coalition,
including MWRD, and who now support the plan to treat waste from the Lowry Landfill
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at the MWRD sewage treatment plant, please explain in writing from EPA 's perspective
the series of events and discussions which led members of the Lowry Coalition to support
the current plan to clean up the Lowry Landfill. Making knowingly false statements to
federal officials is a crime under federal law. If EPA thought the assertions made in the
letter from John Fought were false, did EPA attempt to bring any charges against Mr.
Faught, MWRD or other entities comprising the Lowry Coalition? If EPA made no
attempt to bring charges against Mr. Faught or members of the Lowry Coalition please
explaining the reason for EPA's inaction.
Allegations presented in the 1991 Faught letter apparently represent the Coalition's
understanding, at that time, of the nature of radioactive contamination at the Lowry Site. Since
that time, existing and new information and analyses have been more thoroughly evaluated and
have invalidated the Coalition's 1991 claims. The Coalition has updated its impressions
accordingly. Such evidence may be found in the Lowry Site remedial investigation reports,
baseline risk assessments, and the results of ongoing environmental monitoring at the Lowry
Site. While EPA did not concur with the Coalition's 1991 views, it does not follow that the
Coalition knowingly made false statements.
3. The second document, attached, consists of an end log from the Lowry Landfill indicating
that radioactive waste from Rocky Flats was dumped at the Lowry Landfill: The third
document, also attached, consists of another end log from the Lowry Landfill indicating
that highly toxic hydrazine from Martin Marietta was dumped at Rocky Flats.
The Lowry Landfill File Review Form for Rockwell International (Rocky Flats Plant) contains a
listing of all waste streams produced at the Rocky Flats Plant, but not necessarily taken to the
Lowry Site for disposal. The column marked "06" is used to indicate whether or not a particular
waste was sent to the Lowry Site (Lowry is located on Section 6). Evaporator salts, which are
designated as radioactive, were not sent to Lowry ("N" is for no, in the "06" column).
The Rockwell International file review form and 1991 Coalition letter have been touted as
evidence that radioactive material from the Rocky Flats Plant was disposed at the Lowry Site.
However, waste-hauling records and the results of extensive sampling efforts show that there is
no evidence that radioactive waste from Rocky Flats was disposed at the Site.
The commenter may also have misinterpreted the file review forms for Martin Marietta
Aerospace (Martin). On the Martin review form, it shows that hydrazine was not disposed at the
Lowry Site, and does not indicate that hydrazine was dumped at Rocky Flats.
Site records indicate that Rockwell International disposed of 55,630 gallons of paint sludge,
waste oil, and solvent at the Lowry Site. None of these wastes were radioactive.
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4. As an EPA official, you have specifically denied that man-made radioactive materials
from Rocky Flats were dumped at the Lowry Landfill. You have also said that no
hydrazine from the Martin Marietta facility was dumped at the Lowry Landfill. Please
explain in writing the discrepancy between your statements and the official end log
documents from the Lowry Landfill.
There is no discrepancy between statements made by the Lowry Site Remedial Project Manager
and information contained in the Administrative Record. Please refer to the previous response
for further explanation.
5. You are undoubtedly aware that there is growing public skepticism of the plan to treat
the waste from the. Lowry Superfund site at facilities operated by Metro. Attached are
resolutions unanimously endorsed by the executive boards of the Colorado AFL-CIO and
the Denver Area Labor Federation to "oppose the current plan to treat waste from the
Lowry Superfund site at MWRD facility which could result in radioactive material being
spread throughout the Denver metropolitan area and in Eastern Colorado, thus
endangering the health and safety of the workers and the public at large ". OCA W
maintains that the Lowry Landfill site has not been adequately characterized and that no
one, including the EPA, knows what will be in the toxic soup to which workers and the
public will be exposed.
The pretreated ground water that will be leaving the Lowry Site for further treatment at Metro
and Aurora has been adequately characterized. The existing Lowry Site ground-water database
contains more than 126,780 analytical records. These records provide more than enough basis
for the design and operation of a pretreatment system and for establishing pretreatment
requirements. Additionally, the effluent to be piped from the onsite treatment plant will be tested
to meet Metro and Aurora's pretreatment program requirements. If the pretreated ground water
does not meet the pretreatment requirements, the water will not be sent offsite.
6. OCA W is deeply concerned about the health and safety risks to MWRD workers. As you
are aware, these workers are not covered by OSHA. Currently, the lab workers are not
even protected by a collective bargaining agreement due to the intransigence and union
busting practiced by MWRD management. Trust and confidence that MWRD District
Manager Robert Hite will look after the health and safety of workers in nonexistent.
Congress has determined that State and local governments, including Metro, are not subject to
OSHA regulations. However, while the Metro workers are not covered by OSHA, they are
covered by Metro's Chemical Hygiene Plan (Metro, 1997a). This plan is comparable to a plan
that would be required under OSHA.
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Response to Elmer Dudden VPresident, Pleasant View Water and Sanitation District
June 19, 1997 Letter
The Directors of the Pleasant View Water and Sanitation District fully support
EPA 's proposal to have the Metro District treat the Lowry site groundwater.
The comment is noted.
Response to Sharon Estell's
June 28,1997 Fax
It is dangerous enough to allow industrial waste to be spread on farmland but to
allow Superfund level toxins to be spread in this manner is unthinkable. The
American people are being used as guinea pigs in a scientific experiment of
massive scale. The Lowry Landfill Superfund Site has contamination from
plutonium, dioxin, PCBs [polychlorinated biphenyls], and other man-made
radionuclides that will contaminate our food chain.
The comment is noted. All ground water collected at the Lowry Site will be pretreated prior to
discharge to the sewer system. Concentrations of inorganic chemicals within the Lowry Site
ground water will be lower than for typical industrial discharges.
The quantity of Lowry Site inorganic chemicals that may accumulate in the sewage sludge (or
biosolids) will not affect the "exceptional quality" status of Metro's treated sludge, or biosolids
(See Executive Summary - Human Health, Environmental, and Biosolids Concerns). EPA
recognizes that the commenter may have serious reservations about using sewage sludge as a
fertilizer. This is an important issue that continues to foster lively debate. EPA intends to
carefully collect and evaluate evidence relating to Metro's ongoing biosolids' land application
activities.
There is no historical or sampling evidence of plutonium contamination at the Lowry Site.
Current chemical analyses confirm that the pretreated Lowry Site ground water does not contain
levels of radionuclides that could accumulate in the sewage sludge. Although radionuclide
contamination does not currently appear to be evident, there is an onsite early-warning ground-
water monitoring system currently in operation. This system has been designed to alert EPA and
CDHPE if unacceptable levels of radionuclides appear in ground water. If this scenario were to
occur, Lowry Site water would not be sent offsite until the levels of radioactive contaminants
were reduced to ROD performance standards or pretreatment standards.
The pretreated Lowry Site ground water received at the POTWs will be required to meet strict
influent standards. In addition, the ground water from the Lowry Site that will be treated by
Metro's and Aurora's POTWs will be required to meet cleanup standards in Table 11-2 of the
ROD. These tables include dioxin, PCBs, and radionuclides. The pretreated Lowry Site ground
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water will not adversely affect the quality of the POTWs' influent. A stringent monitoring
program will be implemented to assure that the water is treated to meet State water quality
standards and the requirements of the discharge permits.
Response to Patricia Farmer's
July 10,1997 Letter
On June 26, 1997, CNN Money-line aired a report on the Lowry Landfill
Superfund site and the plan to pump ground water from this site to the
Metropolitan Wastewater Reclamation District for treatment. In this report, you
were quoted as saying: "This is not a precedent-setting proposal. It is being done
at Superfund sites around the country. "
I am a Colorado citizen and former Denver resident, and have tried to keep
informed of toxic cleanups in my state and others. Please send me a list of the
other Superfund sites in the United States where the ground water is being treated
at municipal sewage treatment plants.
There are at least 32 other sites that have been identified as sending contaminated water to a
POTW for treatment. A table that lists the name of the site, location, date of ROD, type of liquid
sent to the POTW (i.e., ground water, leachate, etc.), contaminants of concern, and whether or
not the POTW land applies its biosolids is included in Attachment B.
Responses to Harry Hanks'
May 21,1997 Telephone Memorandum
Do heavy metals accumulate in the body? Isn 't this proposal just going to
transfer heavy metals from Lowry to farmland?
Yes, heavy metals can accumulate in.the body. The body is capable of processing (i.e.,
excreting) certain levels of heavy metals. The biosolids regulations (40 CFR Part 503) consider
the effects of metals on the body and establish safe levels for heavy metals in the biosolids to be
used in crop fertilization. Biosolids have been studied for more than 20 years and EPA believes
that the biosolids regulations are conservative.
Metro used to use DIA [Denver International Airport] property to dump sludge?
Metro participated in a reclamation project in 1996 at DIA. In addition, before the land belonged
to DIA, Metro applied biosolids in the area of DIA. Metro land applies its biosolids according to
the biosolids regulations (40 CFR Part 503).
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Bet\veen NY and Texas, no one wants sewage sludge?
Biosolids are being used nationwide to reclaim the organic matter and nutrient value of the
biosolids. Biosolids are produced in the United States at a rate of 6,856,169 dry tons per year.
Of those solids, 55 percent are land applied. In Colorado, 78 percent of the 60,273 dry tons per
year of biosolids produced each year are land applied. Land application rates in other states
range from 0 percent (Alaska) to 100 percent (Delaware, North Dakota, and Oregon).
Response to the Leslie Hanks/Lucinda Boyd/Bombing Range
Environmental Action for Community Health (B.R.E.A.C.H.)
May 19,1997 Letter
Because the citizens of the eastern plains are to be negatively impacted by this
dangerous proposal, we request that the comment period be extended another 60
days beyond the current May 22, 1977 deadline.
In response to requests from the public, EPA extended the public comment period from April 22
through May 22, 1997. The public comment period was further extended through June 30, 1997
to allow the public additional time to review Site information (including new information
regarding treatment of a portion of the water from the Lowry Site in Aurora's POTW). With
these extensions, the public comment period on the Second ESD lasted more than 90 days.
Responses to M.A. Hanks'
May 12,1997 Letter to Phil Hegeman
/. I feel it will be a great risk to public health and the environment to flow toxic and
hazardous waste materials containing concentrations of plutonium as well as other
manmade radionuclides, inorganic and organic contaminants, from the Lowry Landfill
Site as indicated at the April 2, 1997 Hearing. As we are aware, the plan is to flow waste
from Lowry Landfill through a pipeline which will be connected to the City of Aurora
sewer line. This waste will then flow to the Public Owned Treatment Works in Denver
(Metro Grow), be mixed with sewage, be treated like sewage, the residue liquids will be
dumped into the South Platte River, and the sludge will be transported via trucks
traveling over public roads to be spread on farmlands in Arapahoe and Elbert counties in
the Deer Trail and Agate Colorado area.
The Lowry Site ground water that will be discharged to Metro's and Aurora's POTWs will be
pretreated and will not have the characteristics of a hazardous waste (ignitability, corrosivity,
reactivity or toxicity). During pretreatment, contaminants will be removed to comply with
Metro's and Aurora's pretreatment standards. EPA has no evidence that plutonium or other
man-made radionuclides are present in the Site ground water above background levels.
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Once the water reaches the POTW, it will be treated in an advanced wastewater treatment
system. This system includes primary treatment (removal of solids by screening, skimming,
and settling), secondary treatment (microorganisms are used to remove suspended and
dissolved organics and chlorination is used to kill pathogens), and tertiary treatment for about
half of the flow (nitrification and denitrification to remove ammonia). In addition, the solids that
are recovered from the secondary treatment system are digested in an oxygen-free environment.
The treated sludge, or biosolids, are safe enough to be land applied as fertilizer under 40 CFR
Part 503 regulations.
2. The amount of waste is so enormous at the Lowry Landfill Site that the Colorado
Department of Public Health and Environment indicated in the April 2, 1997 Public
Hearing that they had estimated it would be a 30-year process to flow ground water
containing the waste materials through the pipeline and Aurora City sewer system to
Metro Grow. If this type of hazardous waste flows though those sewer systems, flows
down the South Plane River, and is spread on farm lands over such a great period of time
it will inevitably endanger public health and the environment.
EPA and CDPHE use a 30-year timeframe for planning purposes and for cost comparisons. It is
not possible to predict exactly how long it will take before all the contaminated ground water at
the Lowry Site will be treated. With regard to the addition of pretreated Lowry Site ground water
to the Aurora and Metro sewer systems, there will be no adverse impacts to the quality of the
South Platte River or the quality of Metro's biosolids (See Executive Summary - Human Health,
Environmental, and Biosolids Concerns). The biosolids will be applied as fertilizer according to
strict Federal and State standards designed to ensure that the biosolids are safe for both people
and the land. The biosolids currently produced by Metro are rated "exceptional quality." EPA
and CDPHE will monitor the process to ensure that human health and the environment are
protected.
3. Such contaminants in the sewer lines would be a health risk to Aurora residents and any
workers or others exposed. One example of exposure would be when sewer lines backed
up in homes.
Independent of the Lowry proposal, there is always the potential for sewer workers or home
owners to be exposed to raw sewage. The presence of pretreated ground water within the sewer
system will pose no additional danger. The pretreated water leaving the Lowry Site will be
transported through sewer lines to the Metro and Aurora POTWs. The concentrations of
contaminants in the pretreated Lowry Site ground water will meet Metro's and Aurora's
pretreatment standards. Pretreatment standards for nonhousehold discharges are designed to be
protective of sewer workers.
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4. These liquid residues from the waste dumped into the South Plane River would
contaminate the immediate area and flow downstream contaminating water supplies for
humans, livestock, and irrigated food crops.
Treated water that would be discharged to the South Platte River will be required to meet water
quality standards established in Metro's and Aurora's discharge permits. Permit levels are set to
be protective of the South Platte River, including use as a drinking water supply downstream.
The pretreated water from Lowry will have no measurable effect on the water discharged to the
South Platte River. (See Table ES-2, Executive Summary - Human Health, Environmental, and
Biosolids Concerns.)
5. Where the sludge would be spread on farmlands in Arapahoe and Elbert counties, there
would be great risk to public health and the environment via water run-off from heavy
rains and snow which would wash the contaminated dirt, carrying it to human dwellings.
water supplies, livestock pastures, and food crops. There would also be great risk when
wind storms, common to eastern Colorado, blow the contaminated sludge dirt and spread
it by being carrying it through the air.
In developing pollutant limits for the 40 CFR Part 503 Regulations (EPA's biosolids
regulations), risk assessments were conducted to evaluate the possible impacts to human health
and the environment. As part of these risk assessments, fourteen potential exposure pathways,
including wind and surface water runoff, were evaluated. An exposure pathway is the means by
which a person may come into contact with (be exposed to) contaminants in the environment.
The regulations and stands . for biosolids, and the soil to which they are applied, are based in
part on the results of these risk assessments.
Biosolids (treated sludge) from Metro are land applied as fertilizer to cropland in eastern
Colorado. These biosolids meet EPA's "exceptional quality" criteria, which means the biosolids
can be spread at agronomic rates, just as any other fertilizer. Metro has taken, and is taking, steps
to minimize runoff and inhibit the wind from carrying the biosolids off its property. Such efforts
include allowing thatch to remain when>applying biosolids, farming in strips such that each 350-
foot strip is farmed every other year, and providing buffer strips at the edge of fields that will
filter out solids. Nevertheless, if any biosolids were to leave Metro's property, there would be no
increased risk when compared to other fertilizers.
6. There is no method to remove inorganic wastes at Metro Grow; therefore, the liquid
residue dumped in the Plane River and sludge spread over farm land in Deer Trail and
Agate will, indeed, be hazardous waste., but since the waste will go through the Public
Owned Treatment Works, it will no longer be classified as hazardous by the EPA and
CDPHE even though it will still be the same hazardous material.
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The Lowry Site ground water that will be discharged to Metro's and Aurora's POTWs will be
pretreated onsite and will not have the characteristics of a hazardous waste (ignitability,
corrosivity, reactivity or toxicity). During pretreatment. contaminants will be removed to comply
with Metro's and Aurora's pretreatment standards. As required by the Clean Water Act (1977, as
amended), water discharged from Metro must be protective of the South Platte River and to any
land where biosolids are applied. The pretreated Lowry Site water will have no measurable
effect on Metro's discharge to the South Platte River and will not affect the status of Metro's
"exceptional quality" biosolids. (See Table ES-2, Executive Summary - Human Health,
Environmental, and Biosolids Concerns.)
7. The EPA and CDPHE do not know (no one knows) what mixing all the toxic/hazardous
substances from Lowry Landfill will chemically create and impose upon health and
environment. It seems like this would be of great concern to the EPA and CDPHE.
EPA and CDPHE are very much concerned about the effects that the Lowry Site might have on
human health and the environment. To better understand the potential effects, EPA developed a
comprehensive risk assessment for the ground water, surface water, soils, sediments, landfill
solids, and landfill gas at the Lowry Site. This risk assessment evaluates the additive, or
cumulative, risk at the Site. More detailed information on the risk assessment process as
followed for the Lowry Site can be found in:
Baseline Risk Assessment Shallow Ground-Water and Subsurface Liquids and Deep
Ground-Water Operable Units (EPA, 1992a)
Baseline Risk Assessment Landfill Solids and Landfill Gas Operable Units, Soils and
Surface Water and Sediment Operable Units (EPA, I992c)
. Draft Baseline Risk Assessment Sitewide Risk Issues (EPA, 1993)
The risk assessment is available for public review at the EPA Superfund Records Center and the
Aurora Public Library. '
8. Isn 't it correct that no one will be liable for the waste after it's dumped in the river and
spread on the farm lands? Who will be liable for possible environmental damages and
health injuries resulting from exposure to such contamination?
Under the Superfund law, the liability of any responsible party is not affected by the method of
cleanup selected by EPA. Before being sent to the Metro and Aurora POTWs, all ground water
from the Lowry Site will be pretreated to meet Federal and State standards. Concentrations of
chemicals in the pretreated Lowry ground water will be lower than the concentrations of
chemicals entering the POTWs from local industries. The quantity of Lowry Site inorganic
chemicals that may accumulate in the biosolids will not affect the "exceptional quality" status of
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Metro's treated sludge, or biosolids. (See Executive Summary - Human Health, Environmental,
and Biosolids Concerns.) EPA and CDPHE will monitor the quality of the pretreated Lowry
water that is released to the sewer system and will evaluate Metro's ongoing biosolids land
application and discharge activities.
Response to Comments in the June 30,1997 Letter
from Jack Hawkins/President of the
Denver Area Labor Federation AFL-CIO
/ am writing on behalf of the 88,000 members represented by my organization.
On Thursday, June 26, 1997 representatives of this organization unanimously
adopted a resolution that speaks to a Stiperfitnd plan being reviewed by the EPA.
The "plan " would have materials transported from the Lowry Landfill Superfund
Site to the Metro Wastewater Reclamation District (MWRD) facility in Commerce
City. My organization is adamantly opposed to these materials being shipped,
processed, and in any way handled by MWRD.
The comment is noted.
The workers at MWRD have absolutely rw protection from exposure to the known,
or unknown hazardous materials. They are not covered by OSHA, or any other
Federal, State, or local laws. These employees will be working 'at their own
risk'.
State and local governments, including Metro, are not subject to OSHA regulations.. While the
Metro workers are not covered under OSHA, they are covered by Metro's Chemical Hygiene
Plan (Metro, 1997a). This plan addresses such issues as emergency evacuation procedures,
accident preventing and reporting, waterborne pathogens, and training, among others.
j
Additionally, pretreated water from the Lowry Site will not have the characteristics of a
hazardous waste (ignitability, corrosivity, reactivity or toxicity), and will pose no more additional
risk to sewer line workers or wastewater treatment plant workers than domestic sewage.
It is also our feeling that MWRD has not done a full disclosure to officials or
residents that are downstream on the South Plane River. We feel the disclosure
needs to happen from the treatment plant at 6450 York in Commerce City, CO to
the confluence of the Missouri river in Omaha, NE.
Metro is required to meet the discharge limits established in its permit. Metro is required to
provide "disclosure" under the following circumstances: violation of a law or discharge permit;
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or requesting a change to a discharge permit. The purpose of this public comment period is to
invite comments on the proposed changes to the Lowry Site ROD, which is not a change to
Metro's discharge permit.
The MWRD facility at 6450 York Street in Commerce City, CO simply is not
equipped to handle the different fissile materials that are present at the Lowry
Landfill Superfund Site. Nor is the facility equipped to handle some of the most
toxic non-fissile materials at the Landfill.
The Metro facility is capable of handling all materials expected to be discharged in the pretreated
ground water from the Lowry Site. Fissile materials, or radionuclides, are not expected to be
present, above ROD performance standards, in the pretreated ground water. Nevertheless, there
is an onsite early-warning ground-water monitoring system currently in operation. This system
has been designed to alert EPA and CDPHE if unacceptable levels of radionuclides appear in the
ground water. If this scenario were to occur, Lowry Site water would not be sent offsite until the
levels of radioactive contaminants were reduced to ROD performance standards or pretreatment
standards.
The Metro facility has been evaluated for its ability to treat all materials in the pretreated ground
water. Evaluation criteria included:
Maintaining compliance with Metro's CDPS/NPDES discharge permit
Maintaining compliance with State water quality standards
Achieving risk-based effluent concentration limits developed by EPA for analytes not
regulated by water quality standards
Maintaining "clean sludge" levels of analytes in Metro's biosolids
Preventing interference with Metro's treatment processes
Preventing releases of significant quantities of hazardous air pollutants from Metro'i
facilities
Protecting workers from adverse health and safety effects due to toxic compounds in the
sewer system '
There has also been an ongoin'g labor dispute between the OCA W and MWRD.
The District Manager, Mr. Robert Hite, has employed the services of a regionally
known union-busting firm to handle their labor relations. This dispute has lead to
a level of mistrust that should cause alarm. Under these current circumstances,
treatment of hazardous materials has a heightened danger level.
Labor issues are under the jurisdiction of the Department of Labor. Any labor concerns should
be directed to the Department of Labor and will not be addressed in this responsiveness
summary. Pretreated ground water will meet all pretreatment standards before it is introduced
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into the sewer and the water will be handled at Metro just as any other waste in the sewer is
handled.
For these reasons, \ve demand that the EPA deny the "plan "for treatment of
Lowry Landfill Superfund materials by the Metro Wastewater Reclamation
District in Commerce City, CO. There are too many problems in too many areas
to endanger so many people.
As has been shown in previous responses to comments, the pretreated ground water will not be
harmful to residents or workers.
Responses to Draft Resolution by OCAW Local 2-477
to Colorado AFL-CIO on Labor Dispute
with Metro Wastewater Reclamation District
Whereas, members of OCAW Local 2-477 employed at Metro Wastewater
Reclamation District (MWRD) have been without a collective bargaining
agreement for four years;
Whereas, MWRD under the direction of District Manager Robert Hite has utilized
Mountain States Employers Council, the most notorious union-buster in the Rocky
Mountain region, as its representative for the purpose of collective bargaining;
Whereas, the lack of a collective bargaining agreement and a
grievance/arbitration procedure has forced OCAW to utilize the Colorado court
system to obtain relief resulting in great legal expenses on both sides;
Whereas, MWRD has recklessly spent thousands of dollars of public money to
keep OCAW members from securing a contract, and Mountain States Employers
Council has made thousands of dollars from the public trough;
Whereas, union busting in the public sector to the extent practiced by MWRD and
Robert Hite is almost non-existent;
Whereas, four years of conflict have destroyed any trust bet\veen OCA W and
MWRD;
Labor issues are handled by the Department of Labor. Any labor concerns should be directed to
the Department of Labor and will not be addressed in this responsiveness summary.
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Whereas, MWRD has agreed to a plan to ship toxic waste from the Lowry Landfill
Superfund site to its Commerce City facility, where workers are not protected by
OSHA;
State and local governments, including Metro, are not subject to OSHA regulations. While the
Metro workers are not covered by OSHA, they are covered by Metro's Chemical Hygiene Plan
(Metro, I997a). This plan addresses such issues as emergency evacuation procedures, accident
preventing and reporting, waterborne pathogens, and training, among others.
Whereas MWRD never officially notified OCAWofthis agreement;
Communication problems between Metro and OCAW will not be addressed in this
responsiveness summary.
Whereas, there is increasing evidence that plutonium, americium and other man-
made radionuclides exist at the Lowry Landfill site;
Whereas, this radioactive waste will run through the Aurora sewer system, will be
processed at the MWRD sewage plant, and will be deposited into the Plane River
or as sludge on farmland in Eastern Colorado;
There is no evidence that plutonium, americium or other man-made radionuclides from Rocky
Flats were dumped at the Lowry Site. Nevertheless, there is an onsite early-warning ground-
water monitoring system currently in operation. This system has been designed to alert EPA and
CDPHE if unacceptable levels of radionuclides appear in the ground water. If this scenario were
to occur, Lowry Site water would not be sent-offsite until the levels of radioactive contaminants
were reduced to ROD performance standards or pretreatment standards.
Whereas, the plan by MWRD tf> treat the Lowry Superfund waste poses severe
dangers to worker and public health and could result in an even more serious
environmental disaster;
The risks associated with typical materials found in a sewer are much greater than the risks posed
by pretreated ground water from the Lowry Site. Raw sewage contains such materials as
chemicals (acids, proteins, amino acids, carbohydrates), pathogenic bacteria, enteric organisms
(£. Coli), and viruses (poliovirus and Hepatitis A).
Pretreatment standards for the pretreated water coming from the Lowry Site are set at levels that
are protective of worker health and safety. EPA will require monitoring of the effluent from the
Lowry Site to ensure that an "environmental disaster" does not occur.
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BE IT THEREFORE RESOLVED that the Colorado AFL-CIO does hereby (1)
recognize that four years of union busting and denying a union contract to OCAW
members at MWRD is an outrage and demand that MWRD negotiate in good faith
with OCA W to obtain a contract and end the labor dispute; (2) condemn MWRD
for utilizing thousands of dollars of public money to pay Mountain States
Employers Council for its union busting services and demand that this union
busting firm be fired immediately; (3) oppose the current plan to treat waste from
the Lowry Superfund site at the MWRD facility which could result in radioactive
material being spread throughout the Denver Metropolitan area and in Eastern .
Colorado, thus endangering the health and safety of workers and the public at
large; and (4) call upon the MWRD to replace District Manger Robert Hitefor
his callous disregard for worker rights and the health and safety of all concerned,
(1), (2), and (4): Labor issues are handled by the Department of Labor.
(3): The POTW option will not result in radioactive material being spread throughout the Denver
metropolitan area and eastern Colorado, nor will it endanger the health and safety of workers or
the public at large.
BE IT FURTHER RESOLVED that the Colorado AFL-CIO will communicate this
resolution forthwith to the management and board members of MWRD, the
Environmental Protection Agency, the Colorado Department of Health, the
Mayor of Denver, the Governor of Colorado, and members of the Colorado
Congressional Delegation.
The comment is noted.
Responses to Richard S. Hillier's/Health and Safety Department, OCAW
May 6,1997 and May 15,1997 Letters
/. The Baseline risk assessment conducted by CH2M HILL in 1993 focused only on human
health risks to future populations that may occupy the Lowry site. Additionally, the
assessment provided to our office considered risks only from lead and certain
radionuclides.
The risk assessment conducted by CH2M HILL while not adequate in scope, was more
appropriate for the original ROD requiring onsite treatment of wastes. There is no doubt
that the CH2M HILL risk assessment is not adequate for the proposed amendment to the
ROD.
The OCAW has not seen any risk assessments that address risks to the current
populations that will be potentially exposed to the more than 130 identified hazardous
substances proposed to be transported through the public sewer system. There is little
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doubt that these contaminants will leak from the public sewer pipes into the soil and
potentially into the groundwater beneath the City of Aurora and any other communities
served by these pipes. The risk assessment does not address the effects to the aquatic life
of the South Plan River and all downstream users/uses of this river which will receive the
effluent of the Metro/Lowry wastewater. It does not appear that effluent limits have been
established for all of the contaminants nor have any current limits been factored into the
risk assessment. It does not appear that any risk assessment has been conducted to
determine the effects on users and the environment from the use of Metro Gro fertilizer of
the application of the Metro wastewater sludge on farm land. It is this same sludge that
was deemed a hazardous waste by court ruling in. 1996. It does not appear that any risk
assessment has been conducted on the livestock that graze off the lands where Metro
wastewater sludge has been placed. The addition of the Lowry landfill wastes to the
pubic sewer system will increase both the number and concentration of contaminants in
the sludge. It does not appear that any risk assessment has been conducted on the Metro
treatment plant workers who will be exposed to the Lowry landfill wastes.
EPA developed a three-volume risk assessment for the Lowry Site:
Baseline Risk Assessment, Shallow Ground-Water and Subsurface Liquids and Deep
Ground-Water Operable Units (EPA, 1992a)
Baseline Risk Assessment, Landfill Solids and Landfill Gas Operable Units, Soils and
Surface Water and Sediment Operable Units (EPA, 1992c)
Baseline Risk Assessment, Sitewide Risk Issues (EPA, 1993)
These baseline risk assessments evaluated both current and future exposure pathways for
residential, recreational, and occupational scenarios. During the risk assessment evaluation, it
was determined that there were limited current exposure pathways. As a result, the baseline risk
assessments focused on future risk scenarios. The 1993 baseline risk assessment addressed
radionuclides and lead for all environmental media. The other two baseline risk assessments
addressed chemical contamination, exteept for lead and radionuclides, for all environmental
media.
The Superfund risk assessment process" evaluates potential risks posed at a site under the "no
action," or baseline, scenario. This means that the assessment assumes there will be no action
taken to prevent human exposure to contamination. Consequently, the results of the assessment
are expected to represent the "worst case" exposure scenario. It specifically does not incorporate
any cleanup plans.
The baseline risk assessments did consider a variety of exposure conditions in order to evaluate
appropriate cleanup options. One such exposure scenario assumed that an onsite worker would
consume contaminated ground water (waste pit liquids and shallow ground water from the source
area) over the course of a 25-year work lifetime.
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The risk associated with onsite worker exposure to waste pit liquids and contaminated shallow
ground water, through direct ingestion, was estimated to be about 1 x 10""4 (1 in 10,000). Of the
constituents contributing 99 percent of the total risk for this estimate, about 80 percent of the risk
is associated with the fraction attributable to organic chemicals, which will be removed through
pretreatment prior to discharge. Making a conservative, worst-case assumption that a Metro
worker would consume 1 liter of the pretreated ground water on a daily basis for 25 years, the
associated ingestion risk would be about 2 x 10"5 (2 in 100,000). Using reasonable safety factors,
such as not drinking the water, this risk would be even lower. Assuming a Metro worker only
has limited contact with the water, the resulting risk would be less than the 10"6 (1 in 1,000,000)
risk level established by EPA. The baseline risk assessments provide a more in-depth
explanation of risk and the meaning of risk levels such as 10'6.
The Lowry Site ground water will be pretreated to reduce the levels of contaminants prior to
discharge to the sewer system. Therefore, risk levels associated with the pretreated ground water
will be much less than the risks associated with drinking waste pit liquids and untreated,
contaminated shallow ground water. The baseline risk assessments conducted for the Lowry Site
are more than adequate in scope and detail to provide the necessary information on which to base
remedy decisions. The POTW option will achieve the following remedial action objectives:
prevent human exposure (through ingestion, inhalation, and dermal absorption) to liquids
containing contaminants in excess of the cleanup goals; and
prevent migration of contaminants that would result in ground-water concentrations in
excess of the cleanup goal.
There is no current residential exposure to ground-water contaminants at the Lowry Site. Prior to
being discharged to the sewer system for treatment at the POTWs, Lowry Site ground water will
be pretreated onsite to meet pretreatment requirements. These pretreatment requirements were
developed in accordance with regulatory guidance to protect sewer workers, wastewater
treatment workers, and the treatment processes at the POTW. Even though there is no residential
exposure to raw sewage, this scenario has been anticipated by considering the skin and breathing
exposure pathways for sewer workers. The pretreated water from the Lowry Site will pose no
additional hazard above that already associated with raw sewage.
It is not clear to which "130 identified hazardous substances" the commenter is referring. The
Baseline Risk Assessment for Deep Ground Water and Shallow Ground Water and Subsurface
Liquids (OUs 1 and 6) identified 33 risk assessment chemicals of concern (COCs) with which to
evaluate the risk from contaminated ground water. ROD Table 11-2 presents ground-water
performance standards for 58 contaminants. Metro's preliminary pretreatment standards were
developed for 51 contaminants, consistent with those that have been detected at the Site. For any
contaminant that Metro has not developed a pretreatment standard for, the ROD performance
standard shall apply.
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As with any domestic and industrial wastewater, or treated effluent, the water to be discharged
will retain certain chemical, physical, and biological characteristics. The risks associated with
treated ground water originating from the Lowry Site and discharged to the sanitary sewer system
are comparable to, or less than, risks related to typical household and industrial pretreated
wastewater, which are also discharged to the sanitary sewer.
A separate risk assessment is not required because Metro operates under a discharge permit
issued by CDPHE, pursuant to the CDPS Regulations, 5 CCR 1002-61. This discharge permit
requires Metro to meet standards in its discharge that are protective of aquatic life and other
classifications of the receiving waters in the South Platte River at, and downstream of, the
discharge location. The other uses include water supply, recreational, and agricultural uses.
Monitoring and reporting requirements for Metro ensure that they are in compliance with the
conditions of their permit to protect aquatic life and other designated uses of the South Platte
River.
As stated above, pretreatment standards have been developed for contaminants in the ground
water from the Lowry Site. Again, Metro must meet the requirements of its discharge permit,
which includes the limits determined by CDPHE to be necessary to protect the South Platte
River, aquatic life, and designated use categories.
The commenter is referred to "A Guide to the Biosolids Risk Assessments for the EPA Part 503
Rule" (EPA, 1995), which contains detailed information on the risk assessments conducted for
the Part 503 Rule regulating biosolids application. Comprehensive risk evaluations were
performed in developing these regulations and regulatory limits on biosolids. The risk
assessments used conservative assumptions to ensure protection of public health and the
environment.
The commenter states that "this same sludge...was deemed a hazardous waste by court ruling."
The court ruling did not identify Metro's sludge as a hazardous waste. The sludge taken to the
Lowry Site fifteen to twenty years ago is not the same product as the biosolids that are produced
today. Please see the response to Comment #3, below. .
i
As was discussed above, the commenter is referred to the EPA Part 503 Rule risk assessments
guidance document. These risk assessments addressed potential exposure pathways for
livestock, as well as many other potential exposure pathways. Additionally, Metro is not
applying biosolids to land where livestock graze. Metro applies biosolids to land where dryland
wheat is primarily grown.
Evaluations performed to date indicate that the pretreated Lowry Site ground water will have no
measurable effect on the POTWs' discharge to the receiving stream and that the "exceptional
quality" status of the biosolids produced from wastewater treatment process will not be adversely
affected.
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Pretreatment standards are developed in accordance with regulatory guidance to protect
wastewater treatment plant workers from potential exposures to contaminants. The pretreatment
standards developed for the Lowry Site ground water will be subject to the review and approval
of EPA and CDPHE.
In summary, the addition of pretreated Lowry Site ground water to the sanitary sewer system will
not increase or exacerbate the inherent risk associated with domestic or industrial sewage. EPA
believes that the risk assessments conducted for the Lowry Site have adequately addressed
worker and general public exposure issues associated with the POTW Option. These
assessments have used conservative estimates of potential exposure conditions (including
assuming that a worker would drink untreated waste pit liquids and shallow ground water) and
the results indicate that the potential risks from such exposures are within the range of risks (10"6
to 10"1) considered acceptable by EPA. Any risks posed to workers or the public, by exposure to
the pretreated Lowry Site ground water, would be much less than those risks projected for direct
exposure to untreated contaminated water.
2. Transport of Lowry hazardous substances ( many of which have not been adequately
characterized ) through a public sewer system, under residents' homes, knowing that
these pipes will leak, is irresponsible. It is especially irresponsible in light of the fact
that all of the Lowry wastes can be treated onsite with no risk to the public or off site
environments. According to Parsons Engineering's cost estimates, the difference
between these two options ( i.e., onsite vs. off site treatment) is $1 million over 30 years.
This is an insignificant amount of money considering the potential cleanup costs
associated with leaking sewer pipes and adverse effects on the river and the farm lands
and the adverse publicity to all parties involved with the Metro treatment plant option.
Onsite treatment would actually involve offsite transport, treatment, and disposal of hazardous
wastes (brine sludge and spent chemicals). Therefore, offsite treatment has fewer risks. Under
the POTW option, onsite pretreatment will remove contaminants down to the limitations
imposed by Metro's and Aurora's pretreatment permits. This pretreatment would be performed
with simple processes that pose only nominal failure risk. In addition, this pretreatment would
not produce brine sludge or spent chemicals that could pose a risk to the public when transported
offsite for disposal.
Effluent from the Lowry Site pretreatment facility will be tested to meet strict pretreatment
standards prior to release to the sewer system. Because of these pretreatment standards, the water
moving through the sewer system between the pretreatment facility and Metro and Aurora poses
less of a risk to people and the environment than the raw domestic sewage normally carried in
such a sewer. The water from the Lowry Site pretreatment facility would have no additional
impact beyond that from normal sewage should a leak occur. In addition, because the
pretreatment standards are so stringent, the pretreated Lowry Site water will have no measurable
impact on the quality of water discharged by the Metro facility and will not affect the
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"exceptional quality" status of the biosolids produced by the Metro facility. (See Executive
Summary - Human Health, Environmental, and Biosolids Concerns.)
3. In 1996, a Denver judge ruled against Metro by declaring that the waste sludge from the
Metro plant was hazardous waste. Yet this hazardous waste sludge has been applied to
farm lands and the gardens of residents. This sludge was deemed hazardous before
Metro had received any additional wastes from Lowry. Is this sludge going to be
somehow less hazardous now? It is hazardous now and will continue to be hazardous.
The United States District Court for Colorado ruled that Metro's sludge contained "hazardous
substances;" it did.not rule that Metro's sludge was a "hazardous waste." The substances found
to be hazardous were manganese, iron chloride, cadmium, chromium, copper, lead, nickel, and
zinc. These substances are common metals or compounds of common elements found in
Colorado soils. A hazardous waste is a waste with inherent risk that is regulated under RCRA.
The sludge from Metro has not been classified as a hazardous waste. See the response to
Comment #1, above.
Also, the sludge that Metro disposed of at the Lowry Site contained higher levels of pollutants
than the sludge that Metro produces today. There was no industrial pretreatment program in
place during the period of time that Metro took sludge to the Lowry Site. The quality of today's
sludge meets the criteria for "exceptional quality" under 40 CFR Part 503 regulations. Such a
regulatory classification allows Metro's biosolids to be applied as a fertilizer or soil amendment.
4. The Lowry Landfill waste contains radionuclides above background concentrations.
Based on the March 1994 Record of Decision and the 1992 final RI report the following
statements are correct: 1) Americium-241 is found in the waste pits and shallow ground
water in a concentration 963 times greater than regional background levels; 2)
Plutonium-239 is found in the same locations in a concentration 16 times greater than
regional background levels and 5 times greater in the down gradient weathered Dawson
monitoring wells, and; 3) Americium-241 is found in the deep water monitoring wells at
a concentration 1,963 times above regional background levels found in shallow
groundwater. The CH2M HILL risk assessment employed a screening methodology to
eliminate, from the risk assessment, those radionuclides not deemed to be present for
statistical reasons (including detection limits and background considerations). After this
screening process, the radionuclides remaining were deemed to be significant enough to
be included in the assessment. These included, among others, Cesium-137, Plutonium-
239, Americium-241, etc... The Metro treatment plant is not equipped to perform real-
time monitoring for radioactivity. The workers have no training or proper PPE to work
with such materials. The sewers are not designed to transport this type of hazardous
material. If a person or the Metro equipment/facility becomes radiologically
contaminated, it will go undetected. Workers risk the possibility of bringing this material
home with them.
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Very few samples were analyzed for radionuclides. The few samples that were analyzed
represent a very small portion of the Lowry Landfill Site. It is very possible that
significant hot spots of radiological contamination have gone undetected to date. At the
very least, it cannot be taken for granted that such hot spots do not exist. This is a risk
that does not need to be taken.
Using information contained in the 1994 ROD (EPA, 1994a), 1992 Final RI Report (HLA,
1992a), or the Baseline Risk Assessments (EPA, 1992a; EPA, 1992c; EPA, 1993), we were
unable to reproduce the data presented in this comment. It is acknowledged that there have been
several samples where radionuclides (including plutonium-238, plutonium-239/240, americium-
241, and plutonium-241) appear to have been detected in concentrations that exceeded
background levels. The fact that a particular contaminant was detected in a particular sample on
a particular day does not serve as conclusive evidence that the contaminant is present in the
sample. In response to these sporadic detections of radionuclides, extensive reviews of the
Lowry Site radiological data have been conducted.
These reviews included a focused evaluation of transuranic radionuclide data by HLA published
after the final RI Report (HLA, 1992a). The "Evaluation of the Data Quality and Occurrences of
Transuranic Radionuclides in the Shallow Groundwater and Subsurface Liquids and Deep
Ground water Operable Units" report (HLA, 1992b) assessed the available data for americium-
241, plutonium-241, plutonium-238, and plutonium-239/240 for each operable unit.
This transuranic radionuclide evaluation report also included a detailed evaluation of the likely .
presence of transuranics for shallow and deep ground water. Many of the anomalous results that
were reported in the RI (and presumably form the basis for the data reported in this comment)
were included in the analyses conducted as part of the transuranic radionuclide evaluation report.
Many of these data are uncertain due to high counting errors and analytical detection limits, and
in several cases initially elevated results could not be reproduced after reanalysis of the original
sample, or re-sampling.
As part of the transuranic radionuclide evaluation report, six operable units or systems (e.g.,
u'pgradient ground water, waste-pit liquid, etc.) were assessed for the presence of four transuranic
radionuclides (americium-241, plutonium-238, plutonium-239/240, and plutonium-241). The
results from this assessment were used to categorize the probability of the presence of each
radionuclide in each operable unit as probable, questionable, improbable, not detected, and not
analyzed. The results of the analysis showed that for the 24 possible cases (six OUs with four
radionuclides each) there were 15 cases where the presence of transuranics was considered
questionable, 3 cases where samples were analyzed for transuranics but not detected, 3 cases
where a specific transuranic was not analyzed, two cases where the presence of transuranics was
considered probable, and one case where the presence of transuranics was considered
improbable. In summary, this analysis indicated that while the presence of transuranics was
probable in two cases, for most cases the data were considered "questionable" or transuranic
radionuclides were not detected. For the two cases where the report indicated that the presence
of a radionuclide was probable (americium-241 in waste pit liquids and plutonium-239/240 in
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shallow ground water in the weathered system in the source area), the report also indicates that
there was only moderate duplicate agreement, and counting errors were high. In concluding, the
transuranic radionuclide evaluation report states that "[t]here was no case in which the presence
of transuranics was positively confirmed."
EPA and CDPHE have also found no confirmed source of man-made radioactive contamination
at the Lowry Site. If a significant source of man-made radionuclides were present, one would
expect to find consistent detections of radionuclides, with a strong correlation to certain areas or
sources (e.g., waste pit liquids). What have been found are some sporadic detections of
americium. plutonium, and other radionuclides. For numerous samples, where a detection may
have occurred for. a particular radionuclide in one sampling event, the next sampling event from
the same location would indicate no detection for that same radionuclide. For other samples,
when EPA and CDPHE requested a "recount" based upon high counting errors, the recount
indicated no detection. For example, a particular analysis for plutonium-241 in well B-520
resulted in a concentration of 78 pCi/L with a counting error of +/-40 pCi/L. This means that the
actual result may have been anywhere between 38 and 118 pCi/L. Because of the high degree of
error, a recount was required, and the result of the recount was that plutonium-241 was not
detected at a detection limit of 25 pCi/L.
In addition to reviews of the laboratory data, EPA and CDPHE have conducted detailed reviews
of information available on the wastes disposed of at the Lowry Site. This evaluation concluded
that no radioactive wastes were transported to the Lowry Site from Rocky Flats.
Analytical data and historical records serve as the basis upon which remedial action decisions can
be made. A large body of data has been accumulated to indicate that there is good evidence that
transuranics are not present above background levels in ground water at the Lowry Site.
However, it should be noted that while there is no evidence for a confirmed source of man-made
radioactivity at this site, to err on the conservative side, EPA and CDPHE chose to consider
americium-241 and plutonium-239/240 in the baseline risk assessment. The risk assessment
included evaluation of risks under conditions where an individual would ingest water under
residential conditions (drinking water") from source area wells. The reasonable maximum
exposure (RME) risk to such an individual is 6 x 10"* (6 in 10,000). Of that total risk, plutonium-
239/240 and americium-241 contribute only 6 percent and 2 percent, respectively. By far the
majority (85 percent) of potential risk "is contributed by radionuclides that are present in soils and
water naturally, including radium-226, lead-210, potassium-40, and the uranium isotopes
(uranium-234, -235, and -238). Thus, even though evidence of transuranics in ground water at
the Lowry Site has not been confirmed, transuranics were included in the risk assessment, and
contributed negligibly to the total site risk from ground water.
In response to public concerns about the possible presence of radionuclides at the Site, an
additional evaluation of the radionuclide data from the Lowry Site ground-water database was
performed. This evaluation is presented in Attachment C and is based on the sitewide ground-
water quality database, which contains more than 2,900 records of speciated radionucJide data.
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In addition, this database contains another 933 records of gross alpha and gross beta data for
ground water. Based on the information in this database, EPA and CDPHE believe that the Site
has been sufficiently characterized with respect to radionuclides to adequately assess the
potential impacts to human health and the environment.
Major conclusions from the assessment in Attachment C are:
None of the following man-made radionuclides (that could have originated from Rocky
Flats and been disposed of at Lowry) could be confirmed present in the ground water
beneath the Lowry Site: americium-241; neptunium-239; plutonium-238; plutonium-
239/240; and plutonium-241.
No man-made radionuclides were confirmed present in the following Site wells: GW-
111; GW-112; and MPZ-l. These three wells are specifically identified because they will
be one of the sources of the water that will be piped to the POTW.
Finally, it should be noted that there is an onsite early warning ground-water monitoring system
currently in place. This system has been designed to alert EPA and CDPHE if unacceptable
levels of radionuclides appear in the ground water. If this scenario were to occur, Lowry Site
water would not be sent offsite until the levels of radioactive contaminants were reduced to ROD
performance standards or pretreatment standards.
5. The potential escape of Lowry hazardous substances into the public/environment via the
sewer system and the contamination of the Metro facility will result in afar greater
cleanup effort in the future. There is, according to the Parson's engineering cost
analysis, only a $1 million difference between this proposal and an onsite treatment
proposal. Such a cost difference does not warrant, the increased risk to the public and
Metro workers.
Please see the responses to Comments #1 and 2 of this letter for a detailed discussion of the
results of risk assessments related to potential exposures of the public and workers. As discussed
in those responses, because the Lowry Site pretreated ground water received at Metro will be
required to meet strict influent standards, implementation of this alternative will cause no
measurable increase in risks to public health, including the health of workers, or the
environment.
6. The workers employed by Metro and who will be working with and around the Lowry
hazardous substances are not protected by worker health and safety regulations such as
OSHA. Further, the OCAWMetro workers are not covered by any labor contract and
thus have no protection from recourse (i.e., "whistle blower protection ") when bringing
up H&S issues. This type of fear becomes a serious impediment to reporting H&S
concerns when working with hazardous substances.
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State and local government agencies, including Metro, are not subject to OSHA regulations.
However, while the Metro workers are not covered by OSHA, they are covered by Metro's
Chemical Hygiene Plan (Metro, 1997a). This Plan is comparable to an OSHA plan.
Although OCAW workers at Metro are not covered by a current labor agreement, EPA will
require Metro to have an approved Health and Safety program for all employees. It is EPA's
understanding that Metro has a District-Wide Safety Committee, and a Laboratory Safety
Committee that includes OCAW members. Under current laws, an OCAW member who is a
"whistle blower" would have the same protection as any other Metro District employee.
7. In a January 1997 letter from EPA Region VIII, EPA stated that this proposal "...is a
significant change to a component of the remedy selected in the ROD, but does not
fundamentally alter the overall approach intended by the remedv ". The fact is the entire
approach to the remedy has been altered by this proposal. Instead ofonsite treatment,
treatment will now be effected by a different technology off site. Transport of the Lowry
hazardous substances through the public sewer system will adversely impact the remedy
if indeed this material leaks from the sewers. Additional remedies will be needed to
clean-up contamination due to leakage or accidents associated with the sewer. Finally,
the Metro facility and workforce are not designed to handle radioactive and carcinogenic
materials.
EPA does not consider the POTW proposal to fundamentally alter the overall approach intended
by the remedy or the basic features of the remedy. The NCP, specifically 40 CFR 300.435 (c),
specifies that an ESD be issued if the remedial action differs significantly from the ROD with
respect to scope, performance, or cost. In cases where the differences fundamentally alter the
basic features of the selected remedy with respect to scope, performance or costs, a ROD
Amendment is issued. Although it is not required by the NCP, EPA opted to conduct a public
meeting and invite public comments to receive feedback on the proposed changes.
Section 11.2.2 of the Lowry Site ROD describes the treatment component of the ground-water
remedy. This section suggests treatment options for the contaminated ground water collected at
the Lowry Site but specifies that "treatment technologies shall be evaluated further during RD";
actual selection of treatment technologies shall be subject to EPA approval in consultation with
CDPHE. Because the ROD did not specifically identify a treatment technology, the Respondents
to the RD/RA Order prepared an evaluation of potential treatment options entitled, "Draft
Evaluation of the POTW Option" (Parsons ES, 1996). In this evaluation, the Respondents
evaluated four treatment options including the POTW option. The Respondents' proposed
option, the POTW option, includes pretreatment to meet Metro and Aurora's influent standards
and discharge to the POTW for inorganic and additional organic treatment. The POTW option
was screened out of the Feasibility Study early because of the excessive distance to the nearest
interceptor and the fact that Metro did not accept ground water at the time. However, since the
FS and the issuance of the ROD, the following changes have occurred:
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A new sanitary interceptor and connection line were constructed one-half mile from the
Site.
The City of Aurora has agreed to allow connection of a discharge line from the Site to the
sewer line.
The City of Aurora has a cooperative agreement with Metro to allow water to be
conveyed through the discharge line to Metro's POTW.
Metro and Aurora has agreed to accept Site water for treatment.
The Lowry Site pretreated ground water received at the POTWs will be required to meet strict
influent standards. The ground water from the Lowry Site that is treated by Metro's and Aurora's
POTWs will be required to meet the water cleanup, or performance, standards in Table 11-2 of
the ROD. The pretreated Lowry Site ground water will not adversely affect the quality of the
POTWs' influents. A compliance monitoring program will be implemented to assure that the
water is treated to meet: performance standards in the ROD; State water quality standards; and
the requirements of their CDPS permits.
Metro and Aurora will continue to be required to perform routine inspections and maintenance
such as sewer line cleaning, television and other inspections, and to make repairs as needed. This
program is designed to minimize the potential for sewer lines to leak. The pretreatment
standards established for the Lowry Site ground water are more protective of human health and
the environment than the standards for the raw sewage and industrial waste that the sewer lines
are designed to convey.
The Metro and Aurora facilities are designed to safely treat industrial wastes and sewage. The
treatment processes involve physical, chemical, and thermal processes to separate solids from
water, reduce the level of pathogens, and stabilize volatiles. The pretreated Lowry Site ground
water will be closely monitored for the presence of radionuclides and carcinogens using an onsite
early-warning ground-water monitoring system. This system has been designed to alert EPA and
CDPHE if unacceptable levels of radionuclides appear in the ground water. If this scenario were
to occur, Lowry Site water would not be sent offsite until the levels of radioactive contaminants
were reduced to ROD performance standards or pretreatment standards.
8. If Metro is allowed to treat Lowry hazardous substances then Metro will need to be
designated and designed as a Treatment, Storage and Disposal facility. Is Metro
designed to be such a facility?
As defined by RCRA, Metro does not treat, store or dispose of hazardous waste. Therefore,
Metro does not need to be designated a RCRA Treatment, Storage or Disposal facility (TSDF).
Metro is regulated by the Clean Water Act (1977, as amended) and discharges to Metro are
covered by the pretreatment regulations of the Clean Water Act.
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9. It is not apparent that the risks to the following receptors have been evaluated as a result
of this proposed modification to the ROD:
Current Residents
Groundwater beneath the sewer piping and Metro facility
Soil beneath the sewer piping and Metro facility
People who work on the sewer system
People who excavate around the sewer to install TV cable, phone lines, and
gas/utility lines
Metro workers
Downstream users
Crops and livestock
Current residents: There are no current residents at the Lowry Site, and there is only a slight
chance that offsite residents will be exposed to sewer waters. Although it would be unrealistic to
assume that sewer lines never break or leak, the presence of pretreated Lowry ground water in the
wastewater stream within the sewer systems will pose no additional risk to the public. First,
concentrations of contaminants in the pretreated Lowry ground water will meet Metro's and
Aurora's pretreatment standards. Second, these pretreatment standards for nonhousehold
discharges are more protective of the environment than are the standards for raw household
sewage discharges.
Ground water beneath the sewer piping and Metro facility: It is true that a certain amount of
sewage is lost through transmission as a result of sewer exfiltration. However, there is no
additional risk attributed to the pretreated Lowry Site discharge over and above the risk inherent
with the sewage itself, either from a human exposure perspective or an environmental release
perspective.
Soil beneath the sewer piping and Metro facility: See previous response.
People who work on the sewer system: Individuals who work on the sewer system may face
direct and repeated exposure to sewage. Domestic and industrial sewage are known to be
contaminated with a variety of organic compounds, pathogenic bacteria, and disease-causing
viruses. Contact with sewage can be harmful to human health. In addition, individuals who
enter confined spaces associated with underground sewer lines could face exposure to dangerous
levels of methane or hydrogen sulfide. There is no additional risk attributed to the pretreated
Lowry Site ground water over and above the risk inherent with these typical sewer-related
conditions.
People who excavate around the sewer to install TV cable, phone lines, and gas/utility lines:
There is no additional risk attributed to the pretreated Lowry Site discharge over and above the
risk inherent from the sewage itself, either from a human exposure perspective or an
environmental release perspective. Individuals who come into direct contact with untreated
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sewage in the course of the work activities are more likely to be affected by pathogenic bacteria
or viruses.
Metro workers: Individuals who work at the sewage treatment facility face direct and repeated
exposure to sewage. Domestic and industrial sewage is known to be contaminated with a variety
of organic compounds, pathogenic bacteria, and disease-causing viruses. In addition, individuals
who enter confined spaces associated with underground sewer lines could face exposure to
dangerous levels of methane or hydrogen sulfide. There is no additional risk attributed to the
pretreated Lowry Site discharge over and above the risk inherent with these typical sewer-related
conditions.
Downstream Users/Crops and Livestock: Metro must comply with discharge standards
established by the EPA and CDPHE to protect downstream water users, both human and
ecological, whether the discharge from the Lowry Site is factored into the equation or not.
Consequently, the pretreated Lowry Site discharge will have no effect on the ability of Metro and
Aurora to remain in compliance with these standards.
10. According to Parson's April 1996 cost estimates, this proposal would cost - $ 6.4 million
while an onsite treatment option would cost - $ 7.3 million. Are all of these risks worth -
$ 1 million ? We would hope that even the life of one person is worth far more than $ 1
million.
EPA used the methodology required by the NCP to evaluate the merits of the treatment options
suggested by the Respondents to the RD/RA Order (See Attachment E). This analysis requires
the detailed evaluation of nine criteria. The first two assessments are: 1) overall protection of
human health and the environment and 2) compliancee with ARARs or other Federal and State
environmental statutes. If a remedial alternative-does not meet the first two criteria, it is not
carried over for further analysis. If it meets the first two criteria, it is then reviewed against the
next five criteria: 3) long-term effectiveness and permanence, 4 ) reduction of toxicity, mobility
or volume through treatment, 5) short-term effectiveness, 6) implementability, and 7) cost,
including capital and O&M cost. The final two criteria are modifying criteria and are evaluated
following public comment periods: 8) State acceptance and 9) community acceptance.
EPA compared the two alternatives according to these criteria and concluded that the POTW
option achieves the best balance among the nine criteria. EPA believes that this alternative is
most protective of human health and the environment, achieves better long-term effectiveness,
provides a more significant reduction in toxicity, mobility, and volume through treatment, is
more implementable, and is more cost-effective.
EPA recommended the POTW option for the following reasons. Pretreated ground water from
the Lowry Site will contain only materials that Metro and Aurora are already permitted to receive
and are handling safely and reliably. The pretreated ground water discharged to Metro will meet
requirements that have been designed to assure protection of public health and the environment.
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The biosolids produced by Metro have been given the highest rating under Federal and State
standards and are classified as "exceptional quality." The "exceptional quality" status of the
biosolids produced by Metro will not be adversely affected by the Lowry Site water. These
biosolids are approved for application to farmlands and home gardens. Water discharged to the
South Platte River will also be required to meet all Federal and State standards. To be safe, the
ground water from the Lowry Site and all discharged waters will be carefully monitored to make
sure that all standards are met.
/ /.' Based on the March 25, 1992 final RI report for the shallow groundwater and subsurface
liquids and deep groundwater operable units, it is apparent that the data indicates
significant radiological contamination exists and at the very least the presence of this
contamination cannot be excluded. The following comments are based on the information
provided in this RI report:
The shallow groundwater background levels established for Americium-241,
Plutonium-241 and Plutonium-239/240for the Lowry site are on the order of at
least 10 to 134 times greater than regional background values previously
established for the Rocky Flats site. This would indicate the probability that the
Lowry background values are not true background values but actually much
higher than the true values. Thus, all statements made regarding transuranic
values being below Lowry background (i.e., Lowry upper gradient wells) are not
necessarily true.
Plutonium-241 was detected in concentrations 1.5 to 4 times higher than the
artificially high Lowry upper gradient background well values. This report states
that sampling for Plutonium-241 was too limited to fully assess the potential
degree of contamination. Also it states that Plutonium-241 was not analyzed for
in surface water. Thus, the Lowry site has not been adequately characterized for
Plutonium-241.
Americium-241 was detected in concentrations 100 to 1,000 times higher that
regional background levels. A groundwater sample from the source area
indicated Americium-241 concentrations greater than 8 times the alreadv
artificially high Lowry-background level. This report indicated that proper
concentrations ofAmericium-241 could not be determined because of problems
with analytical procedures. Thus, the Lowry site has not been adequately-
characterized for Americium-241.
Plutonium-239/240 was detected and confirmed in concentrations above both the
regional and Lowry site background levels.
The report states that Cs, Ce and Sr are all present in concentrations above
Lowry background and their presence may be related to previous site activity. It
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would appear on the surface that the use oftransuranic radionuclides was a
common practice associated with this site.
Refer to the response to Comment #4, above (and Attachment C) for a detailed discussion of
radiological data. As a general summary, a detailed review of the radiological data for the Lowry
Site shows no conclusive evidence of a source of man-made radionuclide contamination in
ground water. Some positive results have been reported for transuranic radionuclides (primarily
pIutonium-238, plutonium-239/240, and americium-241). These results have been carefully
reviewed, and in some cases additional analyses (recounting), and supplementary sampling and
analyses have been conducted.
In particular, an extensive review of the transuranic radionuclide data for the Shallow Ground-
water and Subsurface Liquids and Deep Ground-Water Operable Units (OUs 1 and 6) was
completed by HLA after completion of the March 25, 1992 final RI report (HLA, 1992a). The
HLA transuranic radionuclide evaluation report (HLA, 1992b) included assessment of RI data, as
well as additional data resulting from the recount of selected ground water and waste-pit liquids
collected and analyzed for radionuclides during the Additional Site Characterization sampling
events. Much of the information contained in the transuranic radionuclide evaluation report
clarifies earlier discussions related to radionuclide concentrations that are contained in the RI
report. In addition, EPA has conducted independent reviews of the Lowry Site radionuclide
data. A more detailed discussion of the results from these reviews of the radionuclide data is
presented in Attachment C. Summary responses (based on the results shown in Attachment C)
are provided for each bullet under Comment 11 as follows. .
Bullet 1: Based on the results in the HLA transuranic evaluation report, a total of 13 samples
from 8 upgradient wells were analyzed for plutonium-239/240. For 12 of these samples,
plutonium-239/240 was not detected (with detection limits ranging from 0.1 to 0.5 pCi/L).
Plutonium-239/240 was detected in one sample (from well B-520) at 0.59 pCi/L +/- 0.32 pCi/L,
but subsequently was not detected at or above a reporting limit of 0.3 pCi/L, and again at or
above a reporting limit of 0.2 pCi/L. These results indicate that plutonium-239/240 is not present
in the upgradient wells, and thus the upgradient samples are representative of background
conditions (i.e., normally one would expect results for plutonium-239/240 at a background well
location to either show very low [trace] concentrations, or results less than the detection limits
for most standard methodsthis is what the Lowry Site samples show.)
Plutonium-241 was detected in two samples from background locations. Each of these results
contained high counting errors (78 +/- 40 pCi/L and 21 +/- 15 pCi/L). Many of the other
plutonium-241 results were reported with very high detection levels. Because of conflicting
analytical results for plutonium-241 results at upgradient sample locations, the HLA transuranic
report indicated that the presence of plutonium-241 in this system is questionable. Because the
results for plutonium-241 in upgradient wells are considered questionable, they are not used as
background values for comparison against Site concentrations.
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Americium-241 was detected at 6 of 8 background wells at concentrations ranging between 1.3
pCi/L +/- 0.3 pCi/L and 13 pCi/L +/- 6.0 pCi/L. However, according to the HLA transuranic
report, the presence of americium-241 at these locations is considered questionable due to poor
duplicate sample agreement and questionable spectra. Because these background concentrations
are questionable, they are not used for comparisons to Site conditions as a means of showing that
americium-241 is not present onsite.
As an example, americium-241 was not screened out (dropped) as a contaminant of concern for
the risk assessment on the basis of background values greater than onsite values. In fact, both
americium-241 and plutonium-239/240 were considered as contaminants of concern for the risk
assessment, and background concentrations were not subtracted from the exposure point
concentrations in the risk calculations.
Bullet 2: Plutonium-241 is not a Site-specific contaminant of concern due to its low frequency
of detection, short half-life (13.2 years), low relative risk (plutonium-241 emits a very weak beta
particle that cannot penetrate skin), and the lack of evidence that plutonium-239/240 is present in
significant concentrations (i.e., if plutonium-241 were present in significant concentrations,
plutonium-239/240 would also be expected to be present in elevated concentrations.) EPA and
CDPHE concur that plutonium-241 was not analyzed in surface water. However, since the
Surface Water Removal Action was implemented (eliminating the surface water pathway), there
is no need for additional surface water characterization.
Bullet 3: Americium-241 was detected in only one source area well. This one detection, 94 +/-
80 pCi/L, had an excessively high counting error, which means positive identification of
americium-241 is questionable. Also, when this well was resampled, americium-241 was not
detected. Therefore, it was concluded that americium-241 is not present above background
levels in the source area. Fifty-two wells have been sampled for americium-241 across the
Lowry Site. Based on the results from these samples, EPA and CDPHE believe that the Lowry
Site has been adequately characterized for americium-241.
Bullet 4: Plutonium-239/240 was detected in 6 out of 77 samples. Counting errors associated
with the 6 positive results were high, .ranging from 20 percent to 88 percent, and plutonium-
239/240 was detected in two performance evaluation samples and one laboratory blank. For
these reasons, the presence of plutonium-239/240 is considered questionable in ground-water.
Plutonium-239/240 was treated as a contaminant of concern in the Lowry Site risk assessment,
but the presence of plutonium-239/240 has not been confirmed in ground-water.
Bullet 5: The elements cerium, cesium, and strontium are not transuranics and are not
contaminants of concern for the site. The radionuclides cerium-141, cerium-144, cerium-139,
cesium-134, cesium-136, cesium-137, and strontium-85 had detection frequencies of less than 10
percent each and were, therefore, not considered contaminants of concern for the site. Cerium-
143 was not considered a contaminant of concern due to its very short half life (33 hours).
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12. Based on a preliminary review of the EPA document, CERCLA Site Discharges to
POTWs, the following comments and questions are raised for your review and response.
Based on the evaluation criteria outlined on pages ES-1 &2, there is concern as to
whether or not the METRO POTW meets all of the criteria. Specifically, the
following criteria are called into question:
The discharged CERCLA wastewater must not contaminate sludge or become
hazardous to employees at the POTW. The METRO sludge currently is
considered a hazardous waste. This is one of the reasons METRO is a PRP at
Lowry. Since pretreatment will not eliminate inorganic contaminants and only
some of the organics. these CERCLA contaminants may become hazardous to the
POTW employees. This is particularly important, as will be shown later, since
the calculations performed to establish safe levels for worker exposures are not
correct. Further, the METRO workers are not covered by state or federal health
and safety rules. Many of the contaminants are known human carcinogens which
both EPA and NIOSH and many H&S professionals believe have no safe level of
exposure. The evaluation performed in accordance with the EPA document,
"Guidance to Protect POTW Workers from Toxic and Reactive Gases and
Vapors, " besides being done incorrectly, did not take into consideration
synergistic health effects from multiple chemical exposures.
The POTW should have a good record of NPDES permit compliance. METRO, in
1989, received a $1.1 million fine for violations of the Clean Water Act. In 1989 .
METRO announced it was going to discharge 25 million gallons of raw sewage
into the South Plane river. This was prevented by the Adams County
Commissioners. In 1982, METRO was targeted for stricter controls on the
amount of ammonia, chlorine and nitrogen in its treated water. This is not a
great track record.
The potential for volatilization of wastewater contaminants and the potential for
groundwater contamination from transport of the CERCLA wastewater needs to
be evaluated. There is no argument that these contaminants will leak from the
sewer pipes into the soil. They will also volatilize in sewer manholes. The
leakage will reach the groundwater. There has been no written evaluation of
these potentials and how they will be prevented.
The CERCLA wastewater discharge into the POTW's receiving waters must meet
the standards of "no toxics in toxic amounts. " There has been no written
evaluation as to the bioaccumulation effect in the receiving waters, especially
from the inorganic contaminants and radionuclides. According to this document,
an analysis of the fate of the contaminants in the wastewater is required. Dilution
is not an acceptable treatment option.
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The POTW must be knowledgeable of and in compliance with any applicable
RCRA or other environmental statute. Will METRO be considered a TSD
facility?
Responses to this comment are matched to the order in which the bullets are presented in the
comment.
Bullet 1: Metro has established pretreatment limits for the pretreated Lowry Site discharge that
will fully protect the quality of Metro's "exceptional quality" biosolids. Metro's sludge is not a
hazardous waste. The definition of "hazardous waste" under RCRA means that the material has
certain characteristics or properties that make it a hazardous waste or the material is included on
a list of hazardous materials developed by EPA. The characteristics or properties that make a
material hazardous are ignitability, corrosivity, reactivity, and toxicity. Listed hazardous wastes
include categories of use such as wood preserving wastes or solvents.
Regarding employee hazards, Metro has established pretreatment limits to protect worker health
and safety. The calculations performed to establish safe levels for worker exposures appear to be
correct. If the commenter continues to believe they are incorrect, then specific comments as to
the incorrect calculations should be provided.
Metro workers are not covered by Federal or State health and safety rules. However, they are
covered by Metro's Chemical Hygiene Plan (Metro, 1997a). This plan is comparable to a plan
that would be required under OSHA. In addition, discharge from the Lowry Site must meet
standards established by Metro, pursuant to the National Pretreatment Program, to be protective
of worker health and safety. These standards were developed using the following guidance:
EPA's Guidance to Protect POTW Workers from Toxic and Reactive Gases and Vapors
(EPA, 1992b)
ACGW occupational guidelines that are used by OSHA and NIOSH
To date, all limits developed by Metro1 have been clearly presented as "Preliminary." There are a
number of stages in the permitting process still to be undertaken; among them, a review of
updated ACGIH exposure limits and consideration, as the commenter mentions, of synergistic
health effects (please see response to Comment #15, below, fourth bullet).
Bullet 2. These matters are over eight years old. In the past eight years, Metro has had an
excellent record of NPDES compliance. Last year Metro won EPA's National Pretreatment
Program award. Metro has had only one exceedance of numerical discharge permit limits in the
past six years and this exceedance was a chlorine problem caused by a chemical feed failure at
the treatment plant. The exceedance lasted for eight minutes.
The most recent cited example of Metro's noncompliance dates back eight years to Metro's
settling of Clean Water Act (1977, as amended) violations that actually occurred a number of
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years earlier. The other examples cited, of Metro being targeted 15 years ago for ammonia,
chlorine, and nitrogen, and the announcement (actually, previously authorized by both EPA and
the Colorado Department of Health, but later reconsidered after Adams County opposition) of the
raw sewage discharge, have nothing to do with NPDES compliance.
Bullet 3: The potential for volatilization of organic constituents in the sewer, and the
corresponding risk to sewer workers, was addressed by Metro during development of
pretreatment standards. Water will be pretreated on the Lowry Site as necessary to ensure that
sewer workers are not threatened by volatile organic compounds. The potential for sewers to
leak, and the significance of such potential leakage was addressed under the response to
Comment #1, above.
Bullet 4: Metro's discharge will be required to continue to comply with all Federal and State
pollutant-specific standards, which are based on the bioaccumulation effect in the receiving
waters. Metro has established pre.treatment limits for the Lowry Site discharge that will fully
protect the maintenance of water quality standards, including the "no toxics in toxic amounts"
narrative standard. Compliance with the standards will be enforced and the effluent will be
tested using whole effluent toxicity (WET) testing (which has been a requirement of Metro's
discharge permit for a number of years). Effluent that passes the toxicity testing is presumed by
law to comply with the narrative standard.
Bullet 5: See the response to Comment #8, above.
13. What is meant by the statement on pg. 3-1, "In addition, hazardous waste cannot simply
be introduced to sewers outside the POTWproperty boundary, this would violate RCRA
manifesting regulations."?
The referenced statement from the EPA guidance entitled "CERCLA Site Discharges to
POTWs" (EPA, 1990a) means that a hazardous waste generator cannot transport hazardous
wastes offsite with the intent of dumping the waste down the first convenient manhole. Any such
transport would, in fact, violate RCRA manifesting regulations by transporting hazardous waste
without a manifest. Please refer to the definition of hazardous waste in the response to Comment
#12. bullet 1. above.
14. It is assumed that either METRO or the EPA had to evaluate this option in accordance
with Table 41 beginning on page 4-6. Please provide the written responses to each of the
26 considerations presented in this table.
Metro's compliance with the 26 items listed in Table 4-1, POTW Compliance Checklist, of
EPA's "CERCLA Site Discharges to POTWs" (EPA, 1990a) is summarized in the following
table:
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Checklist Item
Response
1. Is the POTW in compliance with its
NPDES permit, or has the POTW been
reported in a recent Quarterly
Noncompliance Report (QNCR)?
Not applicable because Metro discharges
under a state permit (see question number 2)
and Metro has not been reported in a recent
QNCR.
2. Is the POTW in compliance with state
discharge requirements?
The POTW is currently in compliance with
state discharge requirements. Metro operates
under a CDPS permit.
3. If the POTW disposed of the sludge on
land, does it violate standards for PCBs,
cadmium, and pathogens in the sludge?
(Reference 40 CFR Pan 257)
Not applicable because 40 CFR 257 no longer
applies to sewage sludge used or disposed in
accordance with 40 CFR 503. Metro meets all
of the requirements specified in 40 CFR 503.
4. If the pollutants regulated by National
Emission Standard for Hazardous Air
Pollutants (NESHAPS) are present in the
.POTW's sludge, and the sludge is stored
in piles, dried, and/or incinerated, do the
air emissions violate the standards?
Metro does not dry or incinerate its sludge,
and pile storage is indoors. Metro is currently
in compliance with air emissions standards.
5. If pollutants regulated by National
Ambient Air Quality Standards
(NAAQS) are present in the POTW's
sludge, and the sludge is stored in waste
piles and/or incinerated, do the air
emissions violate the standards.
See response to number 4.
6. If the sludges contain PCBs greater than
50 parts per million (ppm), are they
properly disposed of?
Metro sludge does not contain PCB
concentrations greater than 50 ppm. In fact,
the laboratory reported 0 ppm PCBs (See
Attachment A).
If the POTW incinerates its sludge and is
subject to the provisions of 40 CFR §60,
Subpart O, do the air emissions violate
standards for paniculate matter and/or
opacity?
Metro does not incinerate its sludge.
8. If the POTW incinerates its sludge and is
subject to No. 7, does it conduct the
appropriate air monitoring?
See response to number 7.
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Checklist Item
Response
If the POTW dumps its sludge into ocean
waters, does it violate any prohibitions,
limits, or conditions set by its permit, or
does it contain any of the constituents at
certain concentrations prohibited from
dumping?
Metro does not dispose of its sludge in ocean
waters.
10. Is the POTW sludge and/or wastewater
considered a hazardous waste?
Neither Metro's sludge, nor its wastewater are
hazardous waste. See the definition of
hazardous waste in the response to Comment
# 12, bullet 1, above.
11. If the POTW generates hazardous wastes,
does it have a USEPA identification
number?
Metro generates some hazardous wastes (i.e.,
laboratory waste), but these wastes are not
disposed through its treatment plant. These
wastes are not products of the wastewater
treatment process. Metro's USEPA
identification number is COD000111062.
12. Does the POTW properly manifest its
hazardous waste?
Metro manifests its hazardous wastes in
accordance with Colorado Hazardous Waste
Act.
13. Are hazardous wastes packaged in the
manner prescribed for the specific
material in accordance with Department
of Transportation (DOT) and RCRA
regulations?
Metro packages its hazardous wastes in
accordance with DOT and RCRA regulations.
14. Are containers holding hazardous wastes
labeled with the labels prescribed for the
material as specified in DOT and RCRA
regulations?
Metro's hazardous waste containers are
labeled as prescribed in DOT and RCRA
regulations.
15. Does the POTW accumulate hazardous
wastes for 90 days or less before the
waste is picked up by a licensed
transporter? If not, does the POTW
generate less than 1,000 kilogram per
month of waste, transport it more than
200 miles, or have a RCRA storage
permit?
Because Metro is a small quantity generator,
it is allowed by RCRA to accumulate waste
for up to 180 days before it is picked up by a
licenced transporter.
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\ Checklist Item
Response
16. Does the POTW properly dispose of the
sludge classified as hazardous waste?
This is not applicable because the sludge is
not classified as hazardous waste. See
number 10.
17. Does the POTW comply with permit
requirements for sludge use and disposal
(related to NPDES)?
This is not applicable because the sludge is
regulated under 40 CFR Pan 503. See
response to number 18.
18. Does the POTW comply with permit
requirements for sludge use and disposal
(related to §503)?
Metro is in compliance with 40 CFR Part 503
permit requirements and state regulations
governing sludge use and disposal.
19. (Compliance question to be determined
upon finalization of sewage sludge
technical standards.)
See response to number 18.
20. (Compliance question to be determined
upon finalization of the proposed CWA
sludge regulations.)
See response to number 18.
21. (Compliance question to be determined
upon finalization of the proposed RCRA
- Solid Waste Disposal Criteria.)
This is not applicable because Metro does not
co-dispose its sludge with solid waste in
municipal landfills.
22. Is the POTW violating its NPDES permit
and/or sludge use or disposal
requirements as a result of an indirect
Metro is not violating its CDPS permit or
sludge use or disposal requirements as a result
of an indirect discharge.
discharge?
23. Do any industrial discharges violate
categorical standards for discharges to the
POTW?
Industrial discharges unrelated to the Lowry
Landfill Site occasionally violate categorical
standards. Metro has an EPA-approved
Pretreatment Enforcement Management
System (PEMS) in place to respond to such
violations when they occur.
24. If required to develop a Pretreatment
Program, has the POTW developed the
program by the appropriate deadline?
Metro did not develop its Pretreatment
Program by July 1, 1983. Pursuant to a
compliance schedule issued by the State of
Colorado, Metro submitted its Pretreatment
Program to EPA for approval in 1986, and
obtained approval that year.
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Checklist Item
25.
26.
Has the POTW enforced the Pretreatment .
Program and properly implemented
procedures to ensure compliance?
If the POTW treats hazardous wastes, is
it permitted under RCRA, and does it
comply with the permit?
Response
Metro has enforced the Pretreatment Program
and properly implemented procedures to
ensure compliance.
Metro does not accept hazardous wastes for
treatment.
15. Based on a preliminary review of the April 23, 1996 document. Evaluation of the POTW
Treatment Option, Appendix B - Summary of Metro's Pretreatment Requirements, the
column (1) Worker Health and Safety Sewer Cone. Values are not calculated or
evaluated properly. Specifically, the following concerns exist:
This Appendix B lists only 79 of the 176 contaminants of concern listed in the
ROD. Further, none of the radionuclides are listed in this appendix and thus no
worker H&S exposure limits are calculated for radionuclides.
Of the 79 contaminants listed, 49 do not have any H&S exposure limits
calculated. As a result of these first two listed observations it is apparent that the
hazards of the constituents coming into the POTW have not been adequately
characterized with respect to worker health.
For most of the contaminants listed in Appendix B which have a calculated H&S
exposure limit value, this value was taken directly from Table 4-2 of the EPA
document, Guidance to Protect POTW Workers from Toxic and Reactive Gases
and Vapors. These Table 4-2 values were calculated using exposure limit values
that are now out of date and inappropriate for use today. Thus, most of the H&S
worker exposure limit values in this appendix are incorrect.
i
Most important to note is that many of the chemicals which need to have H&S
exposure limits established, act synergistically. It is inappropriate to simply pull
these values off a table (which is what was done). Mixture exposure limit values
need to be calculated for those contaminants that act synergistically or have
similar effect on the same target organs. This has not been done.
There are a number of problems with following the EPA document on protecting
POTW workers. This document is not current with new methodologies for
assessing worker risks and establishing protective limits. A copy of a
methodology is attached for your consideration. The EPA document does not take
into consideration non-volatile substances and metals. Also, it does not consider
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radionuclides. Overall the document is an oversimplification to a very
complicated and serious issue.
The "Draft Evaluation of the POTW Treatment Option" (Parsons ES, 1996) states that all values
reported for Metro's pretreatment requirements were preliminary. The intent of Appendix B was
to offer evidence that Metro was in the process of evaluating pretreatment standards, and that the
types of exposure scenarios listed in the Appendix B summary were being considered. Also, the
values listed in the table were offered for general information only to assess the type of
pretreatment that would be required.
Responses to the individual bullets listed in the comment follow:
Bullet 1: The information presented in Appendix B of the subject evaluation is preliminary,
including the list of chemicals/parameters of concern. Since the draft evaluation was issued,
Metro has added another 65 chemicals/parameters to the list, for a total of 144. This expanded
list now contains the chemicals/parameters of concern for ground water listed in Table 7-1 of the
ROD, exclusive of cobalt, manganese, and thallium, plus chemicals/parameters that have
Colorado Basic Standards for Ground Water, regardless of whether or not they were detected at
the Lowry Site. Cobalt, manganese, and thallium were excluded from the list because they are
not volatile for worker protection, and they do not pose issues with respect to receiving stream
standards, effluent quality or biosolids quality. In addition, Metro is establishing standards for
radionuclides. Thus, the proposed list of chemicals/parameters of concern will protect worker
health and safety. Please also see the response to Comment #1, above.
Bullet 2: Metro has subsequently calculated standards for additional chemicals, and is in the
process of incorporating revised exposure limits. Please see the responses to Comment #1,
above, and Bullet 4, below.
Bullet 3: Please see response to Bullet 4, below.
Bullet 4: As was stated previously, the Worker Health and Safety Based Discharge Screening
Levels listed in Appendix B of the "Draft Evaluation of the POTW Treatment Option" (Parsons
ES, 1996) are preliminary. The screening levels should not be considered the final version of the
list of COCs that will be included in the Pretreatment Discharge Permit, nor as the final health
and safety-based discharge levels. Development of a final list of contaminants and allowable
discharge limits will be based on a four-step process. This process will allow a complete review
of all available physical, chemical, and toxicological information for the COCs, and will allow
development of pretreatment discharge levels that are protective of worker health and safety.
This process involves:
Step 1. Use of EPA guidance (EPA, 1992b) to develop a preliminary list of COCs and
discharge levels;
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Step 2. Use of appropriate physical and chemical parameters and toxicological
information to develop conservative screening criteria for those COCs noi listed in the
EPA guidance;
Step 3. Evaluation of: (a) the impact of exposure to multiple chemicals that affect the
same target organ(s) (an additive effect), and (b) the potential for synergistic effects
between specific chemicals; and,
Step 4. Development of site-specific exposure scenarios to more accurately determine
potential exposure levels.
It should be noted that the "Draft Evaluation of the POTW Treatment Option" (Parsons ES,
1996) is limited to the information generated only by performing a part of Step 1 above. Each of
the four steps is described in greater detail in Attachment D.
Bullet 5: The referenced EPA guidance document is accepted by the technical community and is
used nationally by local, state, and federal regulatory agencies. The methodology submitted by
the commenter, entitled "A Screening Method for Occupational Reproductive Health Risk,"
which appeared in the American Industrial Hygiene Association Journal (See Volume n, p. 586),
is not an EPA-approved procedure. The EPA guidance document does not evaluate potential
worker exposure to nonvolatile substances, metals or alpha- or beta-emitting radionuclides
because it is assumed there would be no complete exposure pathway for these substances.
Response to Don Holstrom's/President, OCAVV
December 11,1997 Letter
The purpose of this letter is to formally request that the EPA: 1) Provide a
minimum 90-day Public Comment Period and provide for public meetings for
potentially impacted and interested parties; and 2) Consider this process a
Amendment to the Record of Decision for Lowry.
i
In response to requests from the public, EPA extended the public comment period from April 22
through May 22, 1997. The public comment period was further extended through June 30, 1997
to allow the public additional time to review Site information (including new information
regarding treatment of a portion of the water from the Lowry Site in Aurora's POTW). With
these extensions, the public comment period on the Second ESD extended more than 90 days.
EPA evaluated the POTW proposal and concluded that it would most appropriately be designated
an ESD, instead of an amendment to the ROD, because the proposal is a significant change to a
component of the remedy selected in the ROD, but does not fundamentally alter the overall
approach intended by the remedy.
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Response to Robert W. Hite's/District Manager,
Metro Wastewater Reclamation District
April 23,1997 Letter
The Metro Wastewater Reclamation District's Board of Directors voted
overwhelmingly on April 15 to reaffirm the District's intent to treat thepretreated
Lowry Site groundwater.
The comment is noted.
Response to John R. Jacus'/Chair, The Lowry Coalition
May 21,1997 Letter
/ am writing on behalf of the Lowry Coalition and its members to provide you
with comments supporting your agency's proposed Second Explanation of
Significant Differences to the Record of Decision ("ROD ")for the Lowry Landfill
Superfund Site ( "Lowry Site "). The Lowry Coalition's current members include
Adolph Coors Company, Amax Research and Development, Inc., the City of
Englewood, the City ofLakewood, the City of Littleton, Conoco, Inc., Gates
Rubber Company, Metro Wastewater Reclamation District, the S. W. Shattuck
Chemical Company, Inc., and Syntex Chemicals, Inc.
The comment is noted.
Response to Nina Judd's Note Attached to the Greg Campbell Article
Good Lord! You cannot seriously be considering letting that toxic sludge go out
that way! Please!
After all the required treatment processes, the treated sludge (called biosolids) applied as
fertilizer will not be toxic. Instead, the biosolids will contain many useful and essential nutrients
required for healthy plant growth.
Before proposing this treatment method, EPA and CDPHE evaluated the available research and
scientific data on this subject and concluded that pretreatment of the Lowry Site ground water
onsite, with additional treatment at Metro, was the best of the available options. EPA and
CDPHE believe Metro and Aurora can safely, reliably, and effectively treat the ground water to
meet Federal and State standards. EPA believes that this alternative is most protective of human
health and the environment, achieves better long-term effectiveness, provides a more significant
reduction in toxicity, mobility, and volume through treatment, is more implementable, and is
more cost-effective.
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Response to Allen Konrath's/Karen Konrath's/Dean Gaudat's
May 9,1997 Letter
// has been brought to my attention that the surrounding landowners, and the
residents of the nearby rural communities are concerned about the hazardous
contents of the waste. It is significant that this waste includes plutonium, and
other manmade radionuclides, and that no treatment process is in place to remove
these radionuclides, from this waste, either at the Lowry Landfill, or at the Metro
Treatment plant, before it is incorporated into the sludge. With this sludge being
placed on thousands of acres offarmground owned by the Metro Wastewater
Reclamation District, in eastern Arapahoe County, near Deer Trail, as well as
other privately owned farmground in Washington and Weld counties, this
proposal has many far reaching implications.
The distribution of any kind of hazardous waste containing plutonium, by any
application, on land that is used to produce food, or where there may be
widespread exposure to the people farming, and residents of the surrounding area
and communities, is not acceptable.
EPA has no evidence that plutonium or other man-made radionuclides are present in the Site
ground water above background levels.
The Metro facility is capable of handling all materials expected to be discharged in the pretreated
ground water from the Lowry Site. The facility has been evaluated for its ability to treat all the
materials in the pretreated ground water. Evaluation criteria included:
Maintaining compliance with Metro's CDPS/NPDES discharge permit
Maintaining compliance with State water quality standards
Achieving risk-based effluent concentration limits developed by EPA for analytes not
regulated by water quality standards
Maintaining "clean sludge" levels of analytes in Metro's biosolids
Preventing interference with Me(ro's treatment processes
Preventing releases of significant quantities of hazardous air pollutants from Metro's
facilities
Protecting workers from adverse health and safety effects due to toxic compounds in the
sewer system
The biosolids distributed by Metro will not be hazardous waste and will meet the stringent
requirements set forth by EPA for "exceptional quality" biosolids. EPA performed more than 20
years of studies on biosolids' application to establish the biosolids standards. These
requirements are more stringent that what is required for commercial fertilizer that is applied to
farmland.
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Response to Robert Legge's Letter
/ am opposed to any waste contamination that will be used on farm land by
Metrogro Sludge due to radioactive and chemical materials (proven) materials. It
will be dangerous to drinking water and food supply from crops.
The comment is noted. All ground water collected at the Lowry Site will be pretreated prior to
discharge to the sewer system. Concentrations of inorganic chemicals within the Lowry Site
ground water will be lower than for typical industrial discharges.
The quantity of Lowry Site inorganic chemicals that may accumulate in the sewage sludge (or
biosolids) will not affect the "exceptional quality'' status of Metro's treated sludge, or biosolids
(See Executive Summary.- Human Health, Environmental, and Biosolids Concerns). EPA
recognizes that the commenter may have serious reservations about using sewage sludge as a
fertilizer. This is an important issue that continues to foster lively debate. EPA intends to
carefully collect and evaluate evidence relating to Metro's ongoing biosolids' land application
activities.
There is no historical or sampling evidence of Site-related plutonium contamination at the Lowry
Site. Although radionuclide contamination does not currently appear to be evident, there is an
onsite early-warning ground-water monitoring system in operation. This system has been
designed to alert EPA and CDPHE if unacceptable levels of radionuclides appear in ground
water. If this scenario were to occur, Lowry Site water would not be sent offsite until the levels
of radioactive contaminants were reduced to ROD performance standards or pretreatment
standards.
Response to Donald F. McClary's/
North Kiowa Bijou Ground Water Management District
May 16,1997 Letter
The purpose of the letter is to Communicate to EPA the vital interest of the North
Kiowa Bijou Ground Water Management District and any such proposal that
would import foreign water or matter in an area that may affect our groundwater
and the drainage system.
The comment is noted.
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Responses to the Donald F. McClary/
North Kiowa Bijou Ground Water Management District
June 23, 1997 Letter
On behalf of the North Kiowa Bijou Ground Water Management District, which is
a political subdivision formed for ground water management under the statutes of
the State of Colorado, I contacted you by letter of May 16, 1997, concerning the
above matter and expressed the concern of the District as to the possible effect of
any proposed dumping under the above project. Based upon the information
presently furnished the District, this project would impact upon the quality of
water within their area and jurisdiction. To this date we have not received any
reply from any of the above parties involved in this matter.
The May 16, 1997 letter was responded to by Joseph Vranka of CDPHE on May 27, 1997. That
letter provided the information you requested in the May 16 letter. When CDPHE was notified
that you did not receive the letter from Mr. Vranka, the letter was sent again on July 8, 1997 by
Joseph Vranka and again on July 10, 1997 by Marc Herman of EPA.
The District is becoming increasingly alarmed about this project and is
particularly concerned in the total lack of any communication or attempt by
anyone to contact them to get their input in this proposed project.
EPA placed announcements in the Denver Post and Rocky Mountain News, mailed over 1,300
fact sheets to the public, held a public meeting on April 2, 1997, and offered a 3-month public
comment period during which comments could be submitted. The District's letters will be
evaluated, along with all other comments received on the proposal, in this responsiveness
summary.
In 1971 and as part of the investigation made by the District of the groundwater
conditions under their jurisdiction, they had a hydrogeologic study of the bedrock
aquifers of their district prepared by Willard Owens & Associates. Included
within that study were regulation recommendations which have been adopted and
followed by the District regarding the protection and preservation of the quantity
and quality of waters in their jurisdiction. One of these recommendations
particularly apply to the above project and reads as follows:
"The surface disposal of all waste materials, including but not
limited to municipal sewage sludge, all well water, feedlot waste,
nuclear by-products, and chemical by-products, shall be done only
in a manner approved by the Board of District. Such disposal
shall be done in a manner to prevent pollution or contamination of
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the bedrock ami alluvial aquifers. Such disposal areas shall be
limited to non-water table areas of impermeable bedrock. "
Metro has applied its biosolids as fertilizer for several years with appropriate approvals from
State and local entities. Metro's land application operations are not within the jurisdiction of the
North Kiowa Bijou Ground Water Management District. The biosolids meet requirements set
forth in 40 CFR Part 503 for "exceptional quality" and, therefore, can be applied as fertilizer to
farmland. The additional water that the Lowry Site will add to the Metro treatment plant will
have no adverse impact on the "exceptional quality" status of the biosolids produced by Metro.
To my own personal knowledge, the jurisdiction and authority of the Ground
Water Management District in this matter of protection of quality and quantify of
waters under their jurisdiction have been tested, both in the Colorado courts and
the Federal courts, who have unanimously upheld the jurisdiction and authority
of the District Board in these matters.
Federal case law interpreting the Supremacy Clause of the United States Constitution has held
that CERCLA and its hazardous waste cleanup objectives preempt conflicting state law (see, e.g.,
United States v. City and County of Denver. 100F.3d 1509 (10lh Cir. 1996)).
The District Board has been informed that the above project includes use of .
surface area for dumping or the waste water disposal in Township 5 South, Range
58 West of the 6th P.M., which includes (although not limited to) Sections 16, 17,
18, 20, and 21. Although this project is immediately adjacent to the boundaries of
the District may also affect the ground waters of the District and be under the
jurisdiction of the District Board, certainly the above sections are directly
established by law, rules and regulations as subject to the jurisdiction of the
North Kiowa Bijou Ground Water Management District Board.
No "dumping" or "waste water disposal" will occur under the POTW option. This option
includes a permitted discharge to the Aurora/Metro Denver sanitary sewer systems of water from
the Lowry Site after treatment to meet pretreatment standards developed by Metro and Aurora
and approved by EPA and CDPHE. Metro currently land applies as fertilizer most of the
biosolids in the area of Deer Trail and Agate. These biosolids are generated from the treatment
of wastewater. The discharge of pretreated ground water from the Lowry Site to the sanitary
sewer system would represent less than 0.01 percent of the daily volume treated by Metro's
treatment plant and City of Aurora's wastewater treatment plant. Based upon current information
and analytical data, the discharge of pretreated Lowry Site ground water to the sanitary sewer
system will not cause a measurable change in the chemical composition of Metro's discharge to
the South Platte River or Aurora's discharge to Sand Creek. In addition, treatment of the Lowry
water at Metro's facility will not adversely affect the "exceptional quality" status of Metro's
biosolids (See Executive Summary - Human Health, Environmental, and Biosolids Concerns).
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Inasmuch as no one has seen fit, as of this date, to either contact or apply to the
District Board for approval on the above project, although it certainly appears
that the same would be subject to their approval and jurisdiction, the District
Board has instructed me to advise each of you of their interest and claim of
jurisdiction in this matter. It is sincerelv hoped that this matter can be resolved
short of the expense and delay of litigation regarding this entire matter.
However, unless some contact is made, the District and its Board feel they may
have no other alternative but to apply to the courts for relief.
Section 113(h) of.CERCLA, 42 U.S.C. Section 96l3(h), prohibits courts from reviewing
challenges to remedial actions selected by EPA, except in certain circumstances, none of which
currently exists.
Response to Dr. John Meinhold's
June 28,1997 Fax
The Lowry Landfill Superfund Site has contamination from plutonium, dioxin,
PCBs, and other manmade radionuclides(such as: americium, tritium, strontium,
cerium, and cesium). Quite simply, these chemicals and radionuclides are some
of the most deadly, toxic, and carcinogenic compounds known to man. What long-
term studies can you cite and document to show that there will be no detrimental
effects to the land, air, water, wildlife, and crops to support your cleanup
procedures? What long-term epidemiological studies can you cite or document to
prove that increased cancer rates, increased mortality rates, or other serious
health effects will not occur?
The comment is noted. EPA has no evidence that plutonium or other man-made radionuclides
are present in the Site ground water above background levels. All ground water collected at the
Lowry Site will be pretreated prior to discharge to the sewer system. Concentrations of inorganic
chemicals within the Lowry Site ground water will be lower than for typical industrial
discharges.
The quantity of Lowry Site inorganic chemicals that may accumulate in the sewage sludge (or
biosolids) will not affect the "exceptional quality" status of Metro's treated sludge, or biosolids
(See Executive Summary - Human Health, Environmental, and Biosolids Concerns). EPA
recognizes that the commenter may have serious reservations about using sewage sludge as a
fertilizer. This is an important issue that continues to foster lively debate. EPA intends to
carefully collect and evaluate evidence relating to Metro's ongoing biosolids' land farming
activities.
The pretreated Lowry Site water received at the POTWs will be required to meet strict influent
standards. The ground water from the Lowry Site that would be treated by Metro's and Aurora's
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POTWs will be required to meet the performance standards in Table 11-2 of the ROD. These
tables include dioxin, PCBs, and radionuclides. The pretreated Lowry Site ground water will not
adversely affect the quality of the POTWs' influent and a stringent monitoring program will be
implemented to assure that the water is treated to meet the performance standards in the ROD,
State water quality standards, and the requirements of the discharge permits.
EPA has issued comprehensive requirements for the use of biosolids generated during the
process of treating wastewater. These requirements are known as the Part 503 Rules (40 CFR
Part 503) that was published in the Federal Register on February 19, 1993. A document entitled,
"A Guide to the Biosolids Risk Assessments for the EPA Part 503 Rule" (EPA, 1995) published
in September 1995, explains the scientific process used to develop pollutant limits for the use or
disposal of biosolids. EPA conducted extensive studies to establish pollutant limits and
management practices that protect human health and the environment from reasonable
anticipated adverse effects of pollutants in biosolids. This guide includes a list of references that
include numerous studies on biosolids and sludge disposal. This list is presented in
Attachment G.
In addition, since 1986, EPA has issued 32 RODs across the nation that include disposal of
wastewater to POTWs. The Superfund Law and the NCP mandate that EPA will review each
remedy no less than every 5 years after initiation of the remedial action to assure that human
health and the environment are protected. During this review, an evaluation is performed to
determine whether the cleanup, or performance, standards in the ROD remain protective of
human health and the environment. EPA will continue the reviews until no hazardous substances,
pollutants or contaminants remain above levels that allow for unrestricted Site use and unlimited
exposure. The list of sites with RODs that include discharges to POTWs is provided in
Attachment B.
Response to Robert J. Miller's/Director, Environmental
Health & Safety, Sundstrand Corporation
May 22, 1997 Letter
i
On behalf of Sundstrand Corporation, we submit the following comments
regarding the proposed ESDfor the Lowry Landfill ROD. We support the
agency's proposed ESD. Our support is based upon a review of the ESD and
communications regarding the same.
The comment is noted.
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Response to Ted Montgomery's
May 14,1997 Letter
/ am against putting Lowry Landfill Superfund waste water in Metrogro sludge
and hauling it out for fertilizer that will get in the water we use out here in the
East end of Arapahoe County.
The comment is noted. All ground water collected at the Lowry Site will be pretreated prior to
discharge to the sewer system. Concentrations of inorganic chemicals within the Lowry Site
ground water will be lower than for typical industrial discharges.
The quantity of Lowry Site inorganic chemicals that may accumulate in the sewage sludge (or
biosolids) will not affect the "exceptional quality" status of Metro's treated sludge, or biosolids.
(See Executive Summary - Human Health, Environmental, and Biosolids Concerns.) EPA
recognizes that the commenter may have serious reservations about using sewage sludge as a
fertilizer. This is an important issue that continues to foster lively debate. EPA intends to
carefully collect and evaluate evidence relating to Metro's ongoing biosolids' land application
activities.
Response to Arthur A. Paine's
May 14,1997 Letter
In response to the proposed "Lowry Landfill Superfund Site Second Explanation
of Significant Differences for the Record of Decision " we, as community business
members, landowners, and rural residents, request that the public comment
period be extended 60 days from May 22, 1997 to end on July 22, 1997, so that
we can review the information provided to us in the libraries. We have not had
sufficient time to get access to this information, and send our comments to you on
this subject.
In response to requests from the public, EPA extended the public comment period from April 22
through May 22, 1997. The public comment period was further extended through June 30, 1997
to allow the public additional time to review Site information (including new information
regarding treatment of a portion of therwater from the Lowry Site in Aurora's POTW). With
these extensions, the public comment period on the Second ESD extended more than 90 days.
Response to David A. Pampu's/Deputy Executive Director,
Denver Regional Council of Governments (DRCOG)
June 30,1997 Letter
The proposed Publicly Owned Treatment Works Option developed by the U. S.
Environmental Protection Agency for the Lowry Landfill Superfund Site has been
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reviewed for consistency with the regional Clean Water Plan. The proposal is
consistent with the Clean Water Plan and is protective of water quality: The
14,400 gallons of Lowry site groundwater to be potentially treated by the
Metropolitan Wastewaler Reclamation District will not have a measurable impact
on effluent discharge quality. This option is appropriate and feasible and will
allow clean-up of groundwater to begin at the site without delay.
The comment is noted.
Response to Richard Price, Jr.'s
May 11,1997 Letter
/ am writing to object to incorporating Lowry Landfill Superfund waste water into
the Metrogro sludge.
The comment is noted. The POTW option does not involve integrating Lowry Site ground water
into Metro sludge (biosolids). All ground water collected at the Lowry Site will be pretreated
prior to discharge to the sewer system. The types of inorganic chemicals within the pretreated
Lowry Site ground water will be no different than the inorganic chemicals that are found in
pretreated wastewater from local industrial dischargers. Concentrations of inorganic chemicals
within the Lowry Site ground water will be lower than for typical industrial discharges.
The quantity of Lowry Site inorganic chemicals that may accumulate in the sewage sludge (or
biosolids) will not affect the "exceptional quality" status of Metro's treated sludge, or biosolids.
(See Executive Summary - Human Health, Environmental, and Biosolids Concerns.) EPA
recognizes that the commenter may have serious reservations about using sewage sludge as a
fertilizer. This is an important issue that continues to foster lively debate. EPA intends to
carefully collect and evaluate evidence relating to Metro's ongoing biosolids' land application
activities.
Land already owned by Metrogro east and south of Deer Trail drains north into
the Muddy Creek, also known as Deer Trail Creek. Muddy Creek has already-
had sludge-fertilized trash and-dirt wash into it from the six-inch rain in 1996 that
washed out the road to the Metrogro site. We want you to be aware that there isj_
miles of live water on the Mitddv Creek and this is an important recharge for the
Foxhill aquifer.
The Muddy runs through our property and into our reservoir which holds 3,000
acre feet of water and is I 3/4 miles from Metrogro's north property line. Our
reservoir is stocked with fish and is home to pelicans, ducks, geese, and small
herons and other water birds. There have been Blue Heron on occasion and it is
a migration stop for Sandhill cranes. Since all of the run-off from Metrogro south
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of us runs into the Muddy and the reservoir, it has become a settling pond for
fertilized sludge.
The comment is noted.
Water pumped from the chemically saturated sand below the Lo\vry Landfill
Superfund will have particles of all 177 chemicals, including plutonium, in it. If
this treated water is clean enough to put in sludge, then why can't it be used for
household use ?
Actually, treated water is not put in sludge, sludge is created from the treatment of water.
Biosolids are then created from treatment of the sludge. (See Executive Summary - Human
Health, Environmental, and Biosolids Concerns.) The pretreated ground water from the Lowry
Site will be clean enough to be discharged to Metro and Aurora for further treatment and both
Metro and Aurora will be able to meet discharge permit requirements, including biosolids
requirements as specified in the Clean Water Act (1977, as amended). These standards protect
the discharge stream (South Platte River) for particular uses, such as drinking water supplied
downstream. Water used for household use must meet requirements specified in the Safe
Drinking Water Act, known as MCLs. Lowry Site ground water will not be treated to MCLs. In
particular, compounds such as chlorides and sulfates are naturally present in the shallow ground
water and make the water not desirable for drinking.
The biosolids that are generated from the treatment of the water and sludge will continue to meet
EPA's criteria for "exceptional quality" biosolids. This means that the biosolids are clean
enough for household use and can be bagged and sold to households.
Contamination from Superfund sludge blown by high winds and run-off will be
felt by people hundreds of miles away. The Muddy Creek runs into the Bijou and
on into the Platte River. Huge dust clouds are carried miles away from the sites,
and the eastern plains are known for high winds.
Metro has a water truck at the Deer Trail site and uses it for dust suppression. Although it is not
ideal to allow dried biosolids to blow in-the wind, if biosolids were to become windblown, it
would not create a health threat. The 40 CFR Pan 503 Regulations, which are designed to ensure
that biosolids' application activities do not threaten human health or the environment, are based
in part on the results of detailed risk assessments. Fourteen different exposure pathways,
including dust inhalation from biosolids' application operations, were evaluated and the
regulatory standards are based upon conservative assumptions incorporated into the assessments.
In addition, Metro's biosolids are classified as "exceptional quality," which means that
contaminant levels in the biosolids are low enough to allow the biosolids to be applied in
unrestricted areas such as farmland and home gardens.
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Response to Bonnie L. Rader/Citizens for Lowry Landfill
Environmental Action Now (CLLEAN)
May 18,1997 Letter
It is my understanding that because of these new issues there will need to be an
extended comment period. CLLEAN will require more time to review the new
information when it is released and then we will submit our comment.
In response to requests from the public, EPA extended the public comment period from April 22
through May 22, 1997. The public comment period was further extended through June 30, 1997
to allow the public additional time to review Site information (including new information
regarding treatment of a portion of the water from the Lowry Site in Aurora's POTW). With
these extensions, the public comment period on the Second ESD extended more than 90 days.
Response to Bonnie Rader's/Citizens for Lowry Landfill
Environmental Action Now (CLLEAN)
June 30 1997 Letter
Note: Throughout this response, the following terms are used interchangeably:
Alternative 2, Alternative 2B, and Modified Alternative 2B. All three terms refer
to the onsite treatment option involving reverse osmosis and evaporation.
Publicly Owned Treatment Works (POTW)
1. CLLEAN's concerns regarding the POTW are not whether it will work as currently
proposed by Denver (City) and Waste Management (WMI). The issue is - does this
proposal offer a clean up of the contaminated water, one that will not adversely impact
our natural resources or citizens living in other neighborhoods. Our position is that the
proposal, without our suggested secondary treatment, is not a clean up. Rather, it is the
disbursement of the contaminants to other neighborhoods. Metro Waste Water should
not pay their share of the clean up with "in kind" through use of the POTW, they should
pay for the secondary treatment requested by CLLEAN. The solution to pollution is not
dilution.
EPA and CDPHE share your concerns about spreading pollution and believe that the POTW
option offers a cleanup of the contaminated ground water with the least impact on natural
resources and other neighborhoods. All of the other proposals, including Modified
Alternative 2B, generate concentrated wastes and brines that must be transported and disposed
offsite. The pretreated ground water leaving the Lowry Site has low concentrations of
inorganics. Additionally, the treatment technologies available for the ground water at the Metro
and Aurora facilities are the best currently available.
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EPA and CDPHE believe that the POTW option is the most technically feasible, cost-effective,
protective, and reliable option. We believe that this alternative achieves better long-term
effectiveness, provides a more significant reduction in toxicity, mobility, and volume through
treatment, is more implementable, more cost-effective, and is protective of human health and the
environment. Metro's role as a responsible party was not a factor in selecting the POTW option.
2. Under the Superfund Law, the legal requirement is that any amount of
contaminated/treated water that is pumped off site through the POTW must be replaced
with a new source of clean water. The only source of clean water available to us is the
water that comes from our aquifers which are currently being depleted at an alarming
rate. WMI and the City state that it will only take pumping a maximum of 10 gallons per
minute (gpm) of "clean " water back into the site. In reality, 10 gpm equals 5.2 million
gallons of water each and every year. Those citizens who utilize water from domestic
wells consider this a tremendous amount of water to be taken from our supply.
The Superfund Laws require that a remedial action comply with all ARARs. The Respondents to
the RD/RA Order do not have surface water rights in the vicinity of the Site. Consequently, they
may not remove water, for consumptive use, from the shallow ground-water (alluvial) aquifer.
Under Colorado water law, water removed from the shallow alluvial aquifer, in hydraulic
communication with surface water, must be replaced if the user does not have surface water
rights. The Respondents to the RD/RA Order have agreed to implement an augmentation plan to
replenish the water removed from the shallow Dawson aquifer, which is tributary to Murphy
Creek surface water. Currently, the Respondents to the RD/RA Order own ground-water rights
to the Dawson, Denver, Arapahoe, and Laramie Fox Hills aquifers that underlay the 3,634 acres
of land owned by the Respondents to the RD/RA Order in the immediate vicinity of the Lowry
Site. These ground-water rights allow the Respondents to the RD/RA Order to extract
approximately 1.3 billion gallons of water per year for beneficial use. The 5.2 million gallons
per year that may be required for augmentation would represent less than 1 percent of the amount
potentially available.
The 5.2 million gallons of water per year also represent a small proportion of the water within the
bedrock aquifers in the Denver Basin. According to Robson (1984), there is approximately 260 x
106 acre feet of water within the aquifers in the Denver Basin. This equates to approximately
85,000,000,000,000 gallons of water. Thfe 5.2 million gallons that would be removed represents
0.000006 percent of the total water available.
Assuming an effective porosity of 45 percent for the Arapahoe, the Respondents estimate that the
average drawdown of the Arapahoe Formation underlying their 3,634 acres will be
approximately 0.02 inch per year. The additional drawdown in the Denver Basin would be less
than 0.1 percent of the current drawdown in the surrounding vicinity. EPA and CDPHE will
review the augmentation issue periodically to evaluate potential impacts to the aquifers from the
water augmentation plan.
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In addition, the Respondents to the RD/RA Order have entered into an agreement with East
Cherry Creek Valley Water and Sanitation District (ECCV) to transfer some of their deep
ground-water rights to ECCV in exchange for shallow ground-water rights adjacent to the Site.
As part of this agreement, ECCV has agreed to supply the Respondents to the RD/RA Order with
shallow ground water for augmentation purposes.
3. The City and WMI are required, by law, to construct the wetlands that were destroyed
during the time that chemicals were disposed at the Lowry Landfill. This wetlands will
require a water source to keep it alive. CLLEAN has recommended that Alternative 2B,
with our suggested addition of a secondary process, will provide an opportunity to clean
the site while preserving the existing water sources in the area. Although the treated
water would not replenish the deeper aquifers, new water sources would not need to be
tapped to support the Wetlands.
The Respondents to the RD/RA Order are required to replace wetlands that were destroyed
during construction of the ground-water collection system component of the Surface Water
Removal Action. The wetlands have already been constructed in an area northeast of the
command post in the Murphy Creek drainage. The wetlands are receiving water from the alluvial
aquifer and surface water flow. Under the POTW option, the water source for these wetlands
will not change because the wetlands were constructed to be self-supporting and require no
additional water sources.
4. Alternative I states that the POTW is removing inorganics. This is incorrect. The
inorganics are either passed through the plant and in to the Plane River, or they are
dispersed into the sludge. The sludge, containing metals and bacteria, is then applied to
the farm land. We concur with the citizens from the Eastern Plains who are complaining
that they do not want the contaminated sludge brought into their neighborhoods. If the
sludge is land applied the heavy metals will slowly accumulate (as e.g. selenium in the
California irrigation water reservoirs). The organic portion of the sludge is used by bio-
growth, however, the heavy mtetals would just accumulate and be in a form that is
susceptible to exposure to the public. Passing the metals through the plant does not
specifically "fix " them into an inert form.
The POTW will remove inorganics. Wastewater treatment systems at a POTW are designed to
treat wastewater. In other words, the POTW is designed to remove contaminants from the water.
Organic compounds are broken down and destroyed by a combination of biological and chemical
processes. Inorganic compounds are removed from wastewater and placed into the settling
solids, where they pose a minimal hazard. If the treatment processes are managed effectively, the
concentrations of inorganics in the biosolids are not only suitable for land application as
fertilizer, but additionally supply micronutrients to soil depleted as a result of crop growth.
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Assuming all of the metals within the Lowry Site ground water will settle to the solids, there will
be no observed difference in the concentrations of metals in the biosolids produced by Metro. In
addition, the biosolids will still comply with EPA's criteria for exceptional quality sludge and
land application. The metals are required to be at concentrations that will not be harmful to crops
or human health or the environment.
Metals are inert compounds. Therefore, they do not need to be "fixed" into an inert form.
5. Treatment system costs: CLLEAN's position is that Alternative 2B, including secondary
process, will cost more at the start up but, it will actually save money over the life of the
process/cleanup. Long-term monitoring needed for the stated processes will escalate the
costs of the cleanup.
The estimated capital and O&M costs of the two alternatives were calculated and compared. Net
present worth costs were estimated by adding the capital costs to the net present value of the
annual O&M costs for 30 years, using an interest rate of 5 percent. The net present worth cost
for Alternative 1 (the POTW option) is estimated at $6,354,000. This includes capital costs for a
lift station, piping, excavation and construction, the sewer connection fees, design and
construction management costs, O&M costs, equipment repair cost, POTW treatment fees, and
water augmentation costs.
The net present worth cost for the Modified Alternative 2B was estimated at $9,300,000. This
includes capital costs for the reverse osmosis system, an iron removal system, an evaporation
system, design and construction management costs, O&M costs, and water augmentation costs.
Long-term monitoring is included for both options and is approximately equal for both.
While the analysis showed a cost differential between onsite and offsite treatment, cost was only
one of the criteria used to evaluate the treatment alternatives: EPA uses nine criteria to evaluate
the merits of Superfund remedies. The first two criteria are: 1) overall protection of human
health and the environment; and 2) compliance with ARARs or other Federal and State
environmental statutes. If a remedial alternative does not meet the first two criteria, it is not
carried over for further analysis. If an alternative meets the first two criteria, it is then reviewed
against five additional criteria: 3) long-term effectiveness and permanence; 4) reduction of
toxicity, mobility or volume through treatment; 5) short-term effectiveness; 6) implementability;
and 7) cost, including capital and O&M cost. The final two criteria are: 8) State acceptance;
and 9) community acceptance.
EPA and CDPHE compared the two alternatives according to these criteria and concluded that
Alternative 1 achieves the best balance between the nine criteria. EPA and CDPHE are
recommending the POTW option because it is the most technically feasible, cost efficient,
protective, and reliable option. This alternative achieves better long-term effectiveness, provides
a more significant reduction in toxicity, mobility, and volume through treatment, is more
implementable, is more cost-effective, and is protective of human health and the environment.
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Alternative 1 was selected over Modified Alternative 2B because there are risks associated with
offsite transport and disposal of brine sludge and spent chemicals. The POTW option uses
simpler treatment processes that are less likely to fail than those in Modified Alternative 2B and
the Metro facility has safeguards that guarantee a more consistent effluent.
6. CLLEAN does not support the claim made by citizens from the Eastern Plains that the
crops will be contaminated by plutonium in the resultant sludge from the POTW. The
evidence just does not exist. CLLEAN continues to be very vigilant regarding the
plutonium and/or radionuclide issue.
EPA agrees that there is no evidence that crops will be contaminated by plutonium in the sludge
or biosolids that result from the pretreated Lowry Site water. Although radionuclide
contamination does not currently appear to be evident, there is an onsite early-warning ground-
water monitoring system currently in operation. This system has been designed to alert EPA and
CDPHE if unacceptable levels of radionuclides appear in the ground water. If this scenario were
to occur, Lowry Site water would not be sent offsite until the levels of radioactive contaminants
were reduced to ROD performance standards or pretreatment standards.
7. CLLEAN supports the Oil, Chemical, and Atomic Workers in their concerns that
chemicals will travel through the POTW. The onsite treatment systems, as suggested by
WMJ and the City, will only treat the chemicals to minimal standards, thus sending
chemical resides and heavy metals to the POTW. Further, as the contaminated waters
are treated, the amount of water should decrease, the concentration of chemicals will
increase. At that point in time, the POTW can not legally receive the liquids.
The pretreated ground water leaving the Lowry Site will be tested to meet Metro's and Aurora's
influent requirements, which will be protective of worker health and safety. In addition, EPA
and CDPHE will require Metro to have an approved health and safety program for all employees
who may be in contact with the water.
i
It has not yet been confirmed that the concentrations of chemical residues and heavy metals in
the Lowry Site ground water will increase over time. Historical data from the onsite treatment
plant suggest that these concentrations may actually decline. The quality of the ground water will
be closely monitored as part of the ongoing performance monitoring programs. EPA and
CDPHE will require changes to process operations or equipment to assure continued compliance
with the performance standards in the ROD and Metro's and Aurora's influent standards.
Treatment of Waste Pit Material Former Tire Pile Area (FTPA)
1. It is disconcerting to note that the models that have been utilized to determine the
treatment of the chemical contamination at the Lowry Landfill Superfund site describe a
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normal household garbage landfill. These models are erroneous and can not possibly
reflect the very real problems that exist at the Lowry Landfill Superfund site. Please
revise the models to reflect the true picture before any final decisions for cleanup are
finalized.
The air model used for the FTPA emissions modeling is the Industrial Source Complex (Release
3) Short Term (ISC3ST) dispersion model. As the name implies, this model simulates industrial
sources, not municipal solid waste landfills. Site-specific data from the FTPA were input into
the model to evaluate emissions from the excavation and the treatment of soils.
2. It is not yet clear how the old tire pile pits will be opened and the onsite controlled
aeration will be accomplished. It is of the upper most importance to CLLEAN that
neither of these activities move fonvard with out the prior construction of a bubble over
the pits as they are opened to prevent the noxious gases from escaping into our
atmosphere. The plan must include safety measures to protect the onsite workers.
Excavation of the FTPA waste pits will be performed so that the cleanup, or performance,
standards stated in the ROD are met. If it is found that these standards cannot be achieved, then
engineering controls such as a bubble, foam suppressant, or other emissions control mechanism
will be used to cover the pits during excavation. Such engineering controls will be evaluated
during RD, if necessary.
3. All gases that escape into the bubble should be piped to the.flarefor destruction.
If a bubble or other engineering controls are used to control emissions from the excavation, then
appropriate treatment methods such as destruction in the onsite landfill gas flare will be
evaluated and a treatment option will be selected. This evaluation will occur during RD.
4. It is important to examine the possibility ofin-situ bacterial treatment for the toxins.
Considering the fact that the flare is removing the methane from the mass, and this
encourages the "bugs " to multiply, this is an important alternative to consider as it
would allow treatment without the exposure of the chemical gases in to the atmosphere.
Treatability tests performed in the FTPA included an enhanced biological degradation test that
simulated an in-situ treatment option. It was found that this method would not adequately reduce
the levels of contaminants. Specifically, tetrachloroethylene concentrations were not reduced
below the Toxicity Characteristics Leaching Procedure (TCLP) regulatory limit and did not
appear to decrease over time. Physical drying/controlled aeration was found to achieve the
remedial action objective of reducing the TCLP-volatile organic compounds concentrations to
below regulatory limits.
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5. CLLEAN supports the cleanup concept that is currently in effect at the Rocky Mountain
Arsenal called the Pica Child. It is our opinion that private industry should be held to
the same standards of cleanup as the military.
The Rocky Mountain Arsenal does not use the pica child cleanup scenario in developing its
cleanup standards. While the Rocky Mountain Arsenal uses a recreational exposure scenario to
develop its cleanup standards, the Lowry Site uses residential and recreational exposure
scenarios.
CERCLA Criteria
The following paragraphs were not bulleted or numbered in the original comments and are
presented here in the order they appear in the original comments.
The CERCLA process uses a variety of criteria to judge the merits of various
alternatives for a proposed remediation. Some of the arguments used in this
document are very questionable relative to their bearing on the selection. For
instance, stating that t\vo trucks of waste are being hauled (Alternatives 2B and
2C)from the site is a detriment based on the criteria of 'Overall Protection of
Health and Environment' is not a valid weighing factor. There is a tremendous
amount of truck traffic around this site and two more trucks a year has to be
considered inconsequential.
The extra truck traffic described in the report would be one truck, loaded with hazardous waste
sludge, per month. While this may be a marginal increase to the truck traffic associated with the
Denver Arapahoe Disposal Site, the transport of hazardous waste from the Lowry Site would
present an increase in risk to human health and the environment in comparison to sewer transport
of pretreated Lowry Site ground water to the POTWs.
The analysis of alternatives implies that the treatments in the alternatives are
similar. This is not the case. The POTW alternative does not treat heavy metals.
They are simply diluted in the mass of sludge. This is not treatment. The costs of
the POTW alternative should not be directly compared to the costs of the options
labeled 2A, 2B, and 2C. These.alternatives truly treat the inorganic heavy metals
in that they are removed from contact with the environment. That cannot be said
about the POTW option.
The comment suggests that the costs of the alternatives should not be compared directly because
the commenter believes that Alternative 1 does not treat metals. As with Alternatives 2A, 2B,
and 2C, Alternative 1 will result in treated water that complies with ARARs and performance
standards in the ROD. EPA does not agree that there is less treatment associated with
Alternative 1. Alternatives 2A, 2B, and 2C will result in the production of highly concentrated
hazardous sludge that will require disposal in a landfill, while Alternative 1 will produce
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biosolids that may be land applied as fertilizer. Alternative 1 does treat metals and therefore the
costs of the alternatives can be compared directly.
In fact, the POTW treatment option may ultimately be detrimental to the
environment. As the sludge is landfarmed, the organic components and necessary
trace metals are used in the biocycle. The heavy metals and salts that are a
concern at Lowry Landfill will simply accumulate in the soil. At some point they
may reach levels that will be detrimental to the land. There are documented cases
where land applied sludges have caused unacceptable metal build up in the soil
over time.
Assuming all of the metals within the Lowry Site ground water would settle to the solids, there
will be no observed difference in the concentrations of metals in the biosolids produced by
Metro. In addition, the biosolids will still comply with EPA's criteria for exceptional quality
sludge and land application. EPA biosolids regulations (40 CFR Part 503) are based on over 20
years of studies. Inorganic standards were established based on crop uptake, human receptors,
ecological receptors, and other pathways. EPA believes these requirements establish
concentrations that are not harmful to crops, human health or the environment.
In CERCLA terms, the reduction of TMV is judged by us to be better for
Alternative 2. The POTW option spreads the materials treated at Metro over a
large volume of sludge and discharge water. The volume of waste is thus
increased and the mobility increases for inorganic materials sent to the POTW.
Alternative 2 reduces inorganic waste volumes and reduces mobility by placing
them in a secure landfill. This criteria favors Alternative 2.
EPA's and CDPHE's evaluation concluded that the oveiall ranking for the TMV category is
approximately the same for both alternatives. Under Alternative 2, metals would be concentrated
and the resulting brine would require disposal in a hazardous waste landfill. While mobility
would be restricted, toxicity and volutne will actually be increased.
Under Alternative 1, metals will be collected in the biosolids produced at the Metro facility. The
biosolids will then be applied as fertilizer on crop land and private gardens. While there will be a
reduction in the toxicity and volume of the Site waste, land application of the biosolids could
create circumstances in which the metals may have some mobility in the environment. The
concentrations and toxicity of these metals would, however, be low.
The community acceptance for Alternatives 2B and 2C were judged negatively
based on plume presence. There is no reason to have a plume. The steam effluent
should be passed through a heat exchanger to recover the heat and preheat the
incoming stream. The example of this type of equipment used in the document,
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Appendix C, aqua-chem evaporative crystallizer, even had this feature. This
should be struck as a negative community acceptance item for Alternatives 2B
and 2C.
This comment is referring to the Respondents' Draft POTW Evaluation (Parsons ES, 1996) and
not to EPA's and CDPHE's technical evaluation of the alternatives. (See Attachment E.) EPA
and CDPHE conducted a separate technical evaluation of the alternatives as part of the ESD
process. It is this technical evaluation that EPA and CDPHE used to develop the
recommendations for selection of the POTW option. In the EPA and CDPHE technical
evaluation, it was assumed that Modified Alternative 2B had full community acceptance (a "5" in
the technical evaluation), which is consistent with the commenter's remarks.
One issue of particular importance to the community is the removal of water from
their aquifer. This is a negative item for community acceptance of Alternative I
and is not addressed in the document. It would appear that the authors took it
upon themselves to decide what was significant to community acceptance without
actually asking the community.
Again, this comment is referring to the Respondents' Draft POTW Evaluation (Parsons ES,
1996) and not to EPA's and CDPHE's technical evaluation of the alternatives. (See
Attachment E.) The authors referred to in the comment are the Respondents to the RD/RA
Order. The commenter's concern, with regard to the authors' failure to interact with the
community, is noted.
EPA and CDPHE conducted their own evaluation of the alternatives. (See Attachment E.) In the
EPA and CDPHE technical evaluation, EPA and CDPHE concluded that Modified Alternative
2B had full community acceptance (a "5" in the technical evaluation). Furthermore, EPA and
CDPHE assumed that Alternative 1 would receive poor community acceptance (a "1" in the
technical evaluation) because of the community's opposition to the water augmentation portion
of Alternative 1. Both of these ratings are consistent with the comment.
Costs within engineering uncertainties are judged to be equal for the alternatives.
Likewise, the short term effectiveness and compliance with ARARs are judged to
be equal for Alternatives I and 2. Implementability will be slightly higher for the
options in Alternative 2. However, the equipment is certainly established
technology and is no more complex than the treatment equipment currently
installed and maintained at the Metro Treatment complex.
The equipment and technology for Alternative 2 is considerably more complex and difficult to
operate and maintain than the equipment and technologies associated with the activated sludge
treatment processes at the Aurora and Metro POTWs. In addition, a higher level of operator
expertise would be required to operate and maintain a chemical precipitation, reverse osmosis,
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and mechanical evaporation onsite plant. Therefore, the category of implementability was
considered to be less attractive for Alternative 2 than for Alternative 1.
The long term effectiveness of the Metro POTW itself can hardly be considered an
issue. However, there is question relative to the site effluent and the long term
effectiveness of the POTW alternative. The combination of remedies to be
installed includes slurry walls and an effective cap. This treatment will effectively
eliminate the majority: of ground and surface water recharge to the site. The
amount of contaminants will not diminish significantly and the net effect could
likely be a significant increase in contamination concentration levels in the
effluent. It is very likely that as the overall effluent stream drops it will be mainly
due to a drop in percentage of the water component. This could easily create an
effluent stream from Lowry that is over the influent limits for the discharge to the
POTW in inorganics. The site treatment plant would be unable to address this
situation and equipment similar to what is available in Alternative 2 may very
well have to be added in the future if Alternative 1 is chosen. On this basis,
Alternative 2 should be judged as more effective for long term effectiveness.
Although the scenario described in the comment is possible, it has not yet been confirmed that
the concentrations of chemical residues and heavy metals in the Lowry Site ground water will
increase over time. Historical data from the onsite treatment plant suggest that these
concentrations may decline.
Ground-water quality will be monitored as part of the ongoing performance monitoring
programs. EPA and CDPHE will require changes to process operations or equipment to assure
continued compliance with the performance standards in the ROD and Metro's and Aurora's
influent standards. Based on existing data, it is not expected that a reverse osmosis system will
be required in the future.
Process Comments ,
Reverse Osmosis - It is common in this type of scenario to install a second stage
RO unit to retreat the brine discharge from the first unit. The efficiency is not as
good as the first pass; however, more water can be recovered. A second stage RO
would typically recover 50% of the primary brine discharge. Thus a 10 gpm
stream with 75% primary recovery would produce 7.5 gpm of clean water and the
2.5 gpm secondary treatment might yield another 1.25 gpm for a total recovery of
8.75 gpm. Numbers from water supply district personnel indicate that a 75%
recover of supply water is considered good. If we can recharge 87.5% of the
treated water with a primary/secondary RO system, along with the condensate
from an evaporative treatment of the 1.25 gpm brine stream, there should be no
need to supply augmentation water. This would remove this line item from the
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cost and have better community acceptance. Also, the size and cost of the
evaporative unit under Alternative 2B would decrease significantly. This
scenario should improve the overall standing of Alternative 2B.
Items discussed in this comment are design issues and will not be addressed because these issues
do not relate to the alternative that has been selected. Whether or not there is a 1-stage or 2-stage
reverse osmosis process does not alter the EPA and CDPHE technical evaluation of the
alternative, since the technical evaluation assumed that appropriate technologies would be used.
Evaporator - As stated earlier under community acceptance, the vapor stream
from the evaporator in Alternative 2B and 2C should be condensed and
recovered. The condensing apparatus can be used as a preheaterfor the
incoming treatment stream as a cost savings.
Again, items discussed in this comment are design issues and will not be addressed because these
issues do not relate to the alternative that has been selected. Design details such as this do not
affect the EPA and CDPHE technical evaluation of Modified Alternative 2B because the
technical evaluation assumed that best available technology would be used.
Wetlands
The onsite recovery of the water from the treatment process could be used to
augment the wetlands program. A recharge system to groundwater would also be
in place so that the water could be diverted either way as necessary. This would
allow for more flexibility in the wetlands design and maintenance, and increase
the likelihood of a successful implementation of the wetlands mitigation project.
Please see the response to Comment #3, under the POTW subsection of the responses to the June
30, 1997 CLLEAN letter.
Treatment of Waste Pit Material Former Tire Pile Area
The off-gas from the treatment of the tire pile pits will have to be captured and
treated. Presumably this could be accomplished with a carbon absorber or by-
sending it through the landfill gas flare. Of specific concern will be the contents
of the off gas and the method of treatment.
Excavation of the FTPA waste pits will be performed in such a manner as to comply with the
performance standards stated in the ROD. If it is found that these standards cannot be met, then
other engineering controls will be considered. If engineering controls are needed to control
emissions from the excavation, then appropriate treatment methods such as destruction in the
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onsite landfill gas flare will be evaluated and a treatment option will be selected. These
evaluations will be conducted during RD.
While the burning of the gas in the flare seems to be a logical and economical
choice, the issue of hazardous waste treatment will arise with this method. These
implications will also have to be addressed in addition to the technical issues.
CLLEAN will be very interested in the specifics of these issues.
The comment is noted. Details, including treatment technologies to comply with ARARs, will
be investigated during RD.
Response to Kenneth Ross'
May 23,1997 Telephone Message
The commenter is opposed to the proposal and is concerned about flooding,
sewage sludge washing into the ravines, and blowing dust. The commenter wants
EPA to guarantee that there will never be a problem in the next 50 years.
These concerns relate to Metro's biosolids' application techniques, which are regulated under
Federal and State laws. In response to expressed public concern, Metro is investigating and
improving its soil conservation practices and land application procedures.
Over the past 20 years, biosolids' management practices in the United States have changed
significantly, moving from disposal toward more beneficial use. Beneficial use of biosolids,
such as land application, is continuing to rise. In a recent poll by a trade industry magazine, 30
states indicated that beneficial use rates are expected to increase and more biosolids will be land
applied in the future.
The biosolids that are spread on Metro's land near Deer Trail, Colorado are classified under
Federal and State regulations as "exceptipnal quality." This means that the concentrations of
pollutants remaining in the biosolids are so low that the biosolids can be applied beneficially to
land anywhere, even home gardens, and the biosolids are regulated as a fertilizer.
Although we do not know everything there is to know about the disposal of biosolids, this topic
has been one of the most extensively studied waste management practices in the United States.
While there can be no absolute guarantees, the past use of biosolids has been reassuring when
used in accordance with acceptable practices.
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Response to Tammie Scott's/President, Strasburg Community Council, Inc.
May 16,1997 Letter
It would be helpful if the deadline for public comment could be extended so that
residents in our area could become more knowledgeable about the issues involved
and about any proposed methods of dealing with any problems that might result.
In response to requests from the public, EPA extended the public comment period from April 22
through May 22, 1997. The public comment period was further extended through June 30, 1997
to allow the public additional time to review Site information (including new information
regarding treatment of a portion of the water from the Lowry Site in Aurora's POTW). With
these extensions, the public comment period on the Second ESD extended more than 90 days.
Response to Charles and Helene Shields'
June 27,1997 Letter
We in New Hampshire stand with those in Colorado who oppose your plan to
pump water contaminated with radioactivity and hazardous wastes from the
Lowry Landfill Superfund Site into the Denver-Metro sewer system, with the toxic
residuals to be sold to an unsuspecting public as "baggedfertilizer" or spread on
America' s farmland for introduction into the food chain.
We always knew the landspreading of sewage sludge was a monumental scam
perpetrated on the American people by the EPA and the waste companies to
dispose of toxic industrial waste on the cheap.
All ground water collected at the Lowry Site will be pretreated prior to discharge to the sewer
system. Concentrations of inorganic chemicals within the Lowry Site ground water will be lower
than for typical industrial discharges.
The quantity of Lowry Site inorganic chemicals that may accumulate in the sewage sludge (or
biosolids) will not affect the "exceptional quality" status of Metro's treated sludge, or biosolids
(See Executive Summary - Human Health, Environmental, and Biosolids Concerns). EPA
recognizes that the commenter may have serious reservations about using sewage sludge as a
fertilizer. This is an important issue that continues to foster lively debate. EPA intends to
carefully collect and evaluate evidence relating to Metro's ongoing biosolids' land application
activities.
There is no historical or sampling evidence of radionuclide contamination at the Lowry Site.
Current chemical analyses confirm that the pretreated Lowry Site ground water does not contain
levels of radionuclides that could accumulate in the sewage sludge. Although radionuclide
contamination does not currently appear to be evident, there is an onsite early-warning ground-
water monitoring system in operation. This system has been designed to alert EPA and CDPHE
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if unacceptable levels of radionuclides appear in ground water. If this scenario were to occur.
Site water would not be sent offsite until the levels of radioactive contaminants were reduced to
ROD performance standards or pretreatment standards.
With regard to the commenter's concerns about land application of biosolids, please refer to the
response to Mr. Kenneth Ross' May 23, 1997 telephone message.
Once these radioactive and hazardous wastes enter the sewer plants, they become
the "property" of the taxpayers who own the wastewater treatment plants and are
ultimately responsible for the financial consequences of dumping these toxic
sludges on land used to grow cattle feed and food crops. And the industries who
dumped these poisons on the land and created these Superfund Sites are off the
hook!
The types of chemicals within the pretreated Lowry Site ground water will be no different than
the chemicals that are found in pretreated wastewater from local industrial discharges. In fact,
concentrations of chemicals in the pretreated Lowry ground water will be lower than for typical
industrial discharges.
Under the Superfund law, the liability of any responsible party is not affected by the method of
cleanup selected by EPA.
Response to Scott B. Smith's/Director, Environmental
Health & Safety Policy, Coors Brewing Company
May 20,1997 Letter
Coors fully agrees with EPA 's decision to consider minor modifications to their
previously selected remedy for the waste materials beneath the former tire pile
area (FTPA) and the approach to the treatment of contaminated groundwater
collected as part of remediation'activities. We concur with EPA's conclusions
presented in the Second ESD that the proposed modifications do not
fundamentally alter the sitewide remedy and that the site wide remedy, as modified
by the proposal, will remain protective of human health and the environment.
Coors applauds the EPA 's willingness to consider the results of the ongoing data
collection efforts and to modify and adapt the overall remedy to be consistent with
the current understanding of Site conditions.
The comment is noted.
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Response to Lori T. Tagawa's/Waste Management of Colorado, Inc.
and Dennis D. Hodman's/Environmental Services, City and County of Denver
May 20,1997 Letter
In light of the new information from recent investigations and proposed changes
to the ROD, the Respondents believe that the remedy as proposed to be modified
in the ESD is protective of human health and the environment and complies with
applicable or relevant and appropriate requirements. In conclusion, we
commend EPA and CDPHEfor considering the options for cost effective
treatment technologies available at this time, realizing that technology has
progressed in the last few years. We strongly support the two changes to the
ROD in the recent ESD.
The comment is noted.
Response to Delores Tippett's/Women Involved in Farm Economics (WIFE)
June 21,1997 letter
What good it will do you to give in to the polluters so they can have more money
and power. From the time the sludge leaves Lowry Landfill the taxpayers are
liable. How can you or your kids eat food grown on that who knows what soil?
Consistent with the requirements of the Superfund law, EPA and CDPHE are requiring the
polluters to clean up the contamination at the Lpwry Site. EPA and CDPHE evaluated several
proposals relating to the treatment of water from the Lowry Site. The following criteria were
used to evaluate the POTW option:
Compliance with Metro's CDPS/NPDES discharge permit
Compliance with State water quality standards
Ability to achieve risk-based effluent concentration limits developed by EPA for analytes
not regulated by water quality standards
Ability to maintain "clean sludge" levels of analytes in Metro's biosolids
Ability to prevent interference with Metro's treatment processes
Ability to prevent releases of significant quantities of hazardous air pollutants from
Metro's facilities
Ability to protect workers from adverse health and safety effects due to toxic compounds
in the sewer system
Denver, WMC, CWM, and Metro have demonstrated to the satisfaction of EPA and CDPHE that
each of these criteria will be met under the POTW option. The pretreated ground water from the
Lowry Site will meet Metro's and Aurora's permitted influent standards, and, once treated, will
meet effluent, or discharge, standards established to protect the South Platte River and Sand
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Creek environments. Also, there will be no adverse impact to the "exceptional quality" status of
Metro's biosolids.
EPA and CDPHE believe that the POTW option offers an effective, reliable, and safe solution to
properly treat the ground water from the Lowry Site.
Response to Mary Ulmer's/Family Farmers
for Environmentally Safe Use of Property (FESUP)
May 15,1997 Letter
In regards to the proposed "Lowry Landfill Superfund Site Second Explanation of
Significant Differences for the Record of Decision " we request that the public
comment period be extended 60 days from May 22, 1997, to end on July 22. 1997,
to give the people of the communities time to review the information, and research
any questions they have. Due to the delay in getting all the documents to the
public libraries, and the limited access to it, due to distance and times the
libraries are open, there are many people in these communities, that are
interested in this issue, that have not had sufficient time to review this information
and send comments to you on this matter.
In response to requests from the public, EPA extended the public comment period from April 22
through May 22, 1997. The public comment period was further extended through June 30, 1997
to allow the public additional time to review Site information (including new information
regarding treatment of a portion of the water from the Lowry Site in Aurora's POTW). With
these extensions, the public comment period on the Second ESD extended more than 90 days.
Response to Roland Wadsworth's June 23,1997 letter
I'm against the murder of Metro wastewater workers and the poisoning of
Coloradans and others for any reason, especially to just save money. I want to go
on record as against the Lowry landfill sludge proposal.
The comment is noted. EPA and CDPHE have a responsibility to protect human health and the
environment. Based upon current data and knowledge, EPA and CDPHE believe the proposed
option is the most effective, reliable, and safe way to handle the ground water at the Lowry Site.
EPA and CDPHE will monitor the ground water and the biosolids to ensure that all applicable
health and environmental standards are met.
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Response to Richard Walker's/President, Applewood Sanitation District
June 12,1997 Letter
The Board of Directors of the Applewood Sanitation District. Jefferson County,
Colorado is in complete agreement with the EPA proposal to have the Metro
District Plant treat ground water from the Lowry Landfill Superfund site which
will be pretreated at the Superfund site. We have complete confidence in Metro
being able to do the treatment and fully protect the health of Metro employees, the
environment and the public at large. As rate payers we believe the proposed plan
is most economic for all parties and gives all parties the greatest return for money
spent.
The comment is noted.
Response to Barbara White's June 26,1997 Letter
The commenter is opposed to placing a superfund waste site at Deer Trail,
Colorado.
There is no proposal to place a Superfund waste site at Deer Trail, Colorado. The POTW option
involves pretreatment of Lowry Site ground water at an onsite treatment plant, followed by final
treatment at the Metro and Aurora wastewater treatment plants. The pretreated ground water will
be piped from the Lowry Site via the sewer system and will comply with the pretreatment
influent standards established for each wastewater treatment plant. Additionally, the pretreated
Lowry Site ground water will not adversely affect the "exceptional quality" status of the biosolids
produced at the Metro plant. The biosolids will continue to be in compliance with all Federal
and State standards.
Response to State Representative Brad Young's
June 30,1997 E-mail
Commenter states that as the State Representative of eastern Elbert and Arapahoe
Counties, he has some concerns about the proposal to send wastewater from the
Lowry Site to Metro. Specifically, he mentions the allegations that plutonium and
hydrazine may be added to the waste stream and concern over the amount of
contaminants the Lowry Site wastewater would add to the waste stream at Metro.
His main concern is that there be adequate safeguards to ensure that the Lowry
Site waste problems aren 't simply transferred somewhere else.
There is no historical or sampling evidence of plutonium or spent rocket fuel (hydrazine)
contamination at the Lowry Site. As part of the Lowry Site cleanup project, EPA conducted
detailed reviews of all information available on the wastes disposed at the Lowry Site. This
H:\DAUVORDPWIN\IOO.WPD 148
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evaluation concluded that no radioactive wastes (e.g., plutonium) were transported to the Lowry
Site from Rocky Flats, and no hydrazine was disposed of at the Lowry Site. Additionally, EPA
and CDPHE will monitor the pretreated ground water leaving the Lowry Site using an "early
warning system." This system has been designed to alert EPA and CDPHE if unacceptable levels
of constituents appear in the ground water. If this scenario were to occur, Lowry Site water
would not be sent offsite until the levels of contaminants were reduced to ROD performance
standards or pretreatment standards.
Metro's biosolids currently meet "exceptional quality" standards. After pretreatment, the level of
contaminants in the Lowry Site ground water will have no measurable effect on Metro's waste
stream and will not adversely affect the "exceptional quality" status of Metro's biosolids. Under
the POTW option, Lowry Site ground water will first be treated onsite to meet Metro's industrial
pretreatment standards and will then be conveyed via a sewer line to Metro's and Aurora's
POTWs for final treatment. It is estimated that the amount of Lowry Site water that will require
treatment would be approximately 10 gallons per minute, or 14,400 gallons per day.' (This
represents only about 0.01 percent of the total daily flow of wastewater to Metro.)
EPA and CDPHE share the concern that solving the environmental problems of one locality not
create problems for another. EPA and CDPHE have a responsibility to protect human health and
the environment and plan to closely monitor Lowry Site activities to ensure that Federal and
State health and environmental protection standards are met.
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References
Bastian, Robert K. 1997. "Biosolids Management in the United States, A State-of-the-Nation Overview."
Water & Environment Technology. Vol 9, No. 5. May. Pp. 45-50.
Camp Dresser & McKee Inc. (CDM). 1993. Final Remedial Investigation Report Soils and Surface Water
and Sediments, Operable Units (4 and 5), Remedial Investigation and Feasibility Study, Arapahoe County,
Colorado. Document Control No. 8543-11.2.3-AXG. January 20.
Coghlan, Andy. 1997. Lamb's Liver with Cadmium Garnish. New Scientist. Vol. 153. No. 2074. March
22. P. 4.
Federal Water Pollution Control Act of 1977, as amended (Clean Water Act). 33 United States Code 466 et
seq.
Goldstein, Nora. 1997. "State Biosolids Management Update." Biocycle. Journal of Composting and
Recycling. Vol. 38, No. 5. May. Pp. 62-66.
Harding Lawson Associates (HLA). 1992a. Final Remediation Investigation Report for the Shallow
Groundwater and Subsurface Liquids and Deep Groundwater Operable Units (/ and 6), Lowry Landfill,
Arapahoe County, Colorado. HLA Job No. 18876,045.10. March 25.
Harding Lawson Associates (HLA). 1992b. Evaluation of the Data Quality and Occurrences of Transuranic
Radionuclides in the Shallow Groundwater and Subsurface Liquids and Deep Groundwater Operable Units,
Lowry Landfill, Arapahoe County, Colorado. HLA Job No. 18876,064.10. Prepared for The Lowry Coalition.
May 11.
Health Physics Society. 1995. What About "Deadly Plutonium." Radiation Protection Professional's
Directory and Handbook 1996-1997. 1995.
Hydro-Search, Inc. and Camp Dresser & McKee Inc. (HS/CDM). 1993. Final Remedial Investigation Report
Lowry Landfill Gas Operable Units (2 and 3), Remedial Investigation and Feasibility Study, Arapahoe County,
Colorado. Document Control No. 8505-11.3.1 -BJL. June 23.
I
Lowder, W. M., Condon, W. J., and Beck, H. L. (Lowder, W. M., et al.). 1964. "Field Spectrometric
Investigations of Environmental Radiation in the U.S.A." The Natural Radiation Environment. J. S. Adams
and W. M. Lowder, ed. University of Chicago Press, Chicago, Illinois.
Metro Wastewater Reclamation District (MWRD). 1997a. Chemical Hygiene Plan: Safety SOPs, Safety
Training, and Communications. April.
Metro Wastewater Reclamation District (MWRD). 1997b. Preliminary Proposed Self-Monitoring
Requirements and Pollutants to Be Limited by Permit for the Lowry Superfund Site Discharge to the City of
Aurora and the Metro District. Prepared by Metro Wastewater Reclamation District. Denver, Colorado.
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United States. NCRP Report No. 50. Prepared by the National Council on Radiation Protection and
Measurements, Bethesda, Maryland. December 27.
National Council on Radiation Protection and Measurements (NCRP). 1987a. "Ionizing Radiation Exposure
of the Population of the United States." NCRP Report No. 93. Bethesda, Maryland. September 1.
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National Council on Radiation Protection and Measurements (NCRP). 1987b. "Risk Exposure of the
Population in the United States and Canada from Natural Background Radiation." NCRP Report Number 94.
Bethesda, Maryland. December 30.
Parsons Engineering Science, Inc. (Parsons ES). 1996. Draft Evaluation of the POTW Treatment Option,
Lovvry Landfill Superfund Site, Remedial Design. Prepared for the City and County of Denver, Colorado,
Chemical Waste Management, Inc., and Waste Management of Colorado, Inc. Parsons Engineering Science,
Inc., Denver, Colorado. April 23.
Parsons Engineering Science, Inc. (Parsons ES). 1997. Treatability Test Plan Former Tire Pile Area Waste
Pits. Denver, Colorado. February 19.
Robson, S. G. 1984. Bedrock Aquifers in the Denver Basin, Colorado--A Quantitative Water-Resources
Appraisal. United States Geological Survey. Open File Report 84-431. Prepared in cooperation with the
Colorado Department of Natural Resources, Office of the State Engineer; Denver Board of Water
Commissioners; and Adams. Arapahoe, Douglas, Elbert, and El Paso Counties. Lakewood, Colorado.
United Nations Scientific Committee on the Effects of Atomic Radiation (UN). 1982. Ionizing Radiation:
Sources and Biological Effects. Report to the General Assembly. Annex 1, UN82. United Nations, New
York, New York.
United States Army Corps of Engineers (COE). 1995. Archives Search Report, Findings, Buckley Field,
Arapahoe County, Colorado. COE St.- Louis District. May.
United States Army Corps of Engineers (COE). 1997. Master Work Plan, Engineering Evaluation/Cost
Analysis, Former Buckley Field (Lowry Bombing and Gunnery Range), Aurora, Colorado. Prepared for the
United States Army Corps of Engineers, Huntsville Division. May.
United States Department of Energy (DOE). 1992. Response to Question 10. CERCLA 104(e) Information
Request of April 23, 1992 for Lowry Landfill Superfund Site. Project No'. 505-08. August 10.
United States Department of Energy (DOE). 1993. Radiation Protection for the Public and the Environment.
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*
United States Environmental Protection Agency (EPA). 1986. Discharge of Wastewater from CERCLA Sites
into POTWs. EPA memorandum to Waste Management and Water Management Division Directors, Regions
I-X. April 15. -
United States Environmental Protection Agency (EPA). 1988a. CERCLA Compliance with Other Laws,
Draft Guidance. EPA Office of Emergency and Remedial Response, Washington, DC. August 8.
United States Environmental Protection Agency (EPA). 1988b. EPA Superfund Program: Lowry Landfill
Information Update Number 2. Region VIII. Denver, Colorado. October.
United States Environmental Protection Agency (EPA). 1989. Preliminary Endangerment Assessment, Lowry
Landfill. Denver, Colorado. Hazardous Site Control Division Contract No. 68-01-7251. EPA Work
Assignment No. 38-8L08. CH2M HILL Master Project No. D63690. July 27.
United States Environmental Protection Agency (EPA). 1990a. EPA Superfund Program: Lowry Landfill
Information Update Number 3. Region VIII. Denver, Colorado. January.
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United States Environmental Protection Agency (EPA). I990b. CERCLA Site Discharges to POTWs,
Guidance Manual. EPA/540/G-90/005. Prepared by The Industrial Technology Division, Office of Water
Regulations and Standards, Office of Water for the Office of Emergency and Remedial Response, United
States Environmental Protection Agency, Washington, DC. August.
United States Environmental Protection Agency (EPA). 1990c. Guidance for Data Usability in Risk
Assessment, Interim Final. EPA/540/G-90/008. Directive: 9285.7-05. Office of Emergency and Remedial
Response, Washington, DC. October.
United States Environmental Protection Agency (EPA). 1991. National Primary Drinking Water Regulations;
Radionuclides. Notice of proposed rulemaking. Federal Register. Vol.56, No. 138, July 18.
United States Environmental Protection Agency. 1992a. Baseline Risk Assessment, Shallow Ground-Water
and Subsurface Liquids and Deep Ground-Water Operable Units, Lowry Landfill, Denver. Colorado. Denver,
Colorado. February.
United States Environmental Protection Agency (EPA). I992b. Guidance to Protect POTW Workers from
Toxic and Reactive Gases and Vapors. EPA 812B92001. June.
United States Environmental Protection Agency. 1992c. Baseline Risk Assessment, Landfill Solids and
Landfill Gas Operable Units, Soils and Surface Water and Sediment Operable Units, Lowry Landfill, Denver,
Colorado. Denver, Colorado. December 1.
United States Environmental Protection Agency. 1993. Draft Baseline Risk Assessment, Sitewide Risk Issues,
Lowry Landfill, Denver, Colorado. Denver, Colorado. April.-
United States Environmental Protection Agency (EPA). 1994a. Record of Decision, Lowry Landfill
Superfund Site, Arapahoe County, Colorado. United States Environmental Protection Agency Region VIII,
Denver, Colorado. March.
United States Environmental Protection Agency (EPA). 1994b. Administrative Order for Remedial
Design/Remedial Action for the Lowry Landfill Superfund Site No. 8. Region VIII. EPA Docket Number
CERCLA VIH-95-05 (RD/RA Order). November.
United States Environmental Protection Agency (EPA). 1994c. Federal Radiation Protection Guidance for
Exposure of the General Public. Proposed recommendation, request for written comments, and notice of
public hearings. Federal Register. Vol. 59, No. 246, December 23.
United States Environmental Protection Agency (EPA). 1995. A Guide to the Biosolids Risk Assessments
for the EPA Part 503 Rule. EPA832-B-93-005. Office of Wastewater Management, Washington, DC.
September.
United States Nuclear Regulatory Commission (NRC). 1997. Radiological Criteria for License Termination:
Final Rule. Federal Register. Vol.62, No. 139, July 21.
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Glossary
absorbed doseThe energy of ionizing radiation absorbed per unit mass of any material. The
common unit of absorbed dose is the rad. One rad is equal to 100 ergs of energy per gram of material.
activity (also radioactivity)The amount of nuclear transformations (disintegrations) of a radioactive
substance that occur over a specific time interval. The common unit of activity is the Curie.
agronomic ratesThe rate at which nitrogen is supplied to plants as a fertilizer in order for the plants
to absorb growth - farmers consider plant needs and soil nutrient levels when applying fertilizer.
aquiferAn underground rock formation composed of materials such as sand, soil, or gravel that can
store and supply ground water to wells and springs. Most aquifers used in the United States are within
a thousand feet of the earth's surface.
as low as reasonably achievable (ALARA)A basic concept of radiation protection that specifies
that exposure to ionizing radiation and releases of radioactive materials should be managed to reduce
doses as far below regulatory limits as is reasonably achievable considering economic, technological,
and societal factors, among other things.
augmentationThe process of adding to or increasing, such as adding a volume of water to an
existing water supply system or aquifer.
backgroundThe presence of a substance in the environment due to conditions other than those
associated with the waste disposal activities at a Superfund site (a site on the National Priorities List).
Examples would be: naturally-occurring metals such as arsenic, copper, and zinc; cosmic or radon
radiation; or radiation from naturally-occurring radioactive minerals such as uranium.
biosolidsWhen wastewater is cleaned, the treated solid, semi-solid, or liquid residues removed are
called biosolids. The Colorado Biosolids Regulation defines biosolids as the accumulated residual
product resulting from a domestic wastewater treatment works. Biosolids do not include grit or
screenings from wastewater treatment works, grease, commercial or industrial sludge, or domestic or
industrial septage. Biosolids do not include animal manures, untreated septage, municipal solid wastes,
hazardous wastes, industrial sludges such as those generated by oil and gas refining operations, or grit
and screening removed from wastewater'during preliminary treatment.
capital costThe costs of items such as buildings, equipment, engineering, and construction.
chemicals of concernThe most prevalent and toxic chemicals at a Superfund site (a site on the
National Priorities List).
Clean Water Act of 1977, as amended (CWA)The objective of this law is to restore and maintain
the chemical, physical, and biological integrity of the nation's waters and is achieved through the
control of discharges of pollutants to surface waters.
co-disposalA waste disposal technique used at the Lowry Site from 1965 to 1980. Liquid industrial
wastes were dumped into unlined trenches or pits, and municipal refuse was added to soak up the
liquids.
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Comprehensive Environmental Response, Compensation and Liability Act of 1980, as amended
(CERCLA)A Federal law passed in 1980 and amended in 1986 by the Superfund Amendments and
Reauthorization Act. CERCLA created a special tax that goes into a Trust Fund, commonly known as
Superfund, to investigate and clean up inactive hazardous waste sites.
counting errorA measure of the uncertainty or error associated with a single result at a
predetermined confidence level. Typically this uncertainty is calculated at the 95 percent confidence
level, and is expressed as the expected range of activity concentrations that a sample could contain
with 95 percent confidence.
CurieA special unit of activity equal to a nuclear transformation (disintegration) rate of 3.7 x 10'°
disintegration's per second. One picocurie is equal to 10 '2 Curies, which is approximately 2
disintegrations per minute. The Curie was originally defined as the amount of radioactivity in one
gram of radium-226.
effective dose equivalentA unit of radiation dose equivalent adjusted for organ risk. Effective dose
equivalent is a dose to organs adjusted for different radiation types and by an organ weighting factor to
account for organ sensitivity to the effect of radiation. Effective dose equivalent is measured in units
of rem.
"exceptional quality" biosolidsA classification for biosolids under Federal and state regulations
that means that the concentrations of pollutants remaining in the biosolids are so low that the biosolids
can be applied beneficially to land anywhere, even home gardens. Biosolids are regulated as a
fertilizer.
Explanation of Significant Differences (ESD)As a result of new information submitted during the
remedial design/remedial action process, EPA may make a significant change to a component of the
remedy. If this change does not fundamentally alter the overall approach intended by the remedy, then
EPA publishes a document that provides an explanation of the reasons for the change.
flareA piece of equipment (a burner) used to bum landfill gas after collection; the burner and flame
are enclosed.
former tire pile area (FTPA)A 3,0-acre area near the center of the Lowry Site where approximately
eight million old tires were stockpiled.
ground waterWater found beneath the earth's surface that fills pores between materials such as
sand, soil, or gravel. In aquifers, ground water occurs in quantities that can be used for drinking water,
irrigation, and other purposes.
hazardous substanceAs defined by Section 101(14) of CERCLA, any substance EPA has
designated for special consideration under the Clean Air Act (CAA), Clean Water Act (CWA), or
Toxic Substances Control Act (TSCA), and any "hazardous waste" under the Resource Conservation
and Recovery Act (RCRA).
hazardous wasteUnder RCRA, the definition of hazardous waste means that either; (1) the material
has certain characteristics or properties that make it a hazardous waste, or (2) the material is included
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on a list of hazardous materials developed by EPA. The characteristics or properties that make a
material hazardous are ignitability, corrosivity, reactivity, and toxicity.
inorganicsMaterial such as sand, salt, iron, calcium salts, and other mineral materials. Inorganic
substances are of mineral origin, whereas organic substances are usually of animal or plant origin.
land applicationThe process of applying biosolids to land to serve as a soil amendment.
MetroThe Metro Wastewater Reclamation District is a large Publicly Owned Treatment Works
(POTW), or wastewater treatment plant, serving the greater Denver area.
minimum detectable activity (MDA)The MDA is the activity level that a specific instrument and
technique can be expected to detect 95 percent of the time.
mixed wasteA waste that contains both a hazardous waste, as defined under RCRA, and a
radioactive waste, as defined under the Atomic Energy Act.
monofillA solid waste disposal cell used at the Lowry Site to contain tire shreds.
National Oil and Hazardous Substances Pollution Contingency Plan (NCP)Regulations that
provide the organizational structure and procedures for preparing for and responding to discharges of
oil and releases of hazardous substances, pollutants, and contaminants.
NCP criteriaNine criteria identified in the NCP: overall protection of human health and the
environment; compliance with all Federal and state environmental laws; long-term effectiveness and
permanence; reduction of toxicity, mobility, or volume through treatment; short-term effectiveness;
implementability; cost-effectiveness; state acceptance; and community acceptance. Each cleanup
alternative at a Superfund site (a site on the National Priorities List) is evaluated using these nine
criteria.
National Pollutant Discharge Elimination System (NPDES) ProgramThis is the national
program for issuing, monitoring, and enforcing permits for direct discharge of treated wastewater to
surface waters.
National Pretreatment ProgramThis national program establishes standards to control pollutants
which pass through treatment processes in POTWs or which may contaminate sewage sludge, or
biosolids.
operation and maintenance (O&M) costsOperating labor costs, maintenance materials, energy,
disposal costs, and administrative costs.
primary treatmentThe first stage in a wastewater treatment process in which solid materials are
removed from the incoming wastewater. Large debris may be removed by screens or may be reduced
in size by grinding devices. Inorganic solids are removed in grit channels, and much of the organic
suspended solids are removed by sedimentation. A typical primary treatment system should remove
approximately one-half of the suspended solids in the incoming wastewater.
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Publicly Owned Treatment Works (POTVV)A wastewater treatment system that serves a segment
of the public. Wastewater is typically delivered to a POTW via sewer lines.
radA unit of radiation absorbed dose.
radioactive decayThe spontaneous transformation of an unstable atom into one or more different
nuclides accompanied by either the emission of energy and/or particles from the nucleus of the
unstable atom.
Radioactivitysee "activity".
Record of Decision (ROD)A public document that explains which cleanup alternative(s) will be
implemented at a Superfund site (a site on the National Priorities List).
rem (radiation equivalent man)A unit of radiation dose equivalent from ionizing radiation to the
total body or any internal organ or organ system. It is equal to the absorbed dose in rads multiplied by a
quality factor (to account for different radiation types). A rem effective dose equivalent (ede) is a dose
to organs adjusted for different radiation types and by an organ weighting factor to account for organ
sensitivity to the effect of radiation. A millirem (mrem) is 1/1,000 of a rem.
Remedial Action (RA)The actual construction or cleanup phase that follows the remedial design of
a selected cleanup alternative at a Superfund site (a site on the National Priorities List).
Remedial Design (RD)An engineering phase in which technical drawings and specifications are
developed for the subsequent remedial action at a site on the National Priorities List.
Remedial Investigation/Feasibility Study (RI/FS)The RI is a study that collects and analyzes
information about the nature and extent of contamination at a Superfund site (a site on the National
Priorities List). The FS identifies and evaluates the most appropriate cleanup technologies for a
Superfund site.
Resource Conservation and Recovery Act of 1976, as amended (RCRA)The Federal law
controlling the generation, treatment, transportation, storage and disposal of hazardous wastes.
Respondents to the RD/RA Order-r-Parties to the Lowry Landfill Administrative Order for RD/RA.
These parties are required to perform a remedial design described in the Record of Decision and to
implement the design by performing a remedial action.
riskThe incremental probability of an individual developing cancer over a lifetime as a result of
exposure to a potential carcinogen. A cancer risk of 1 x 10 * is one additional case of cancer (over
background levels) per million people exposed (a one in a million chance of getting cancer). The
Superfund regulations specify that 1 x 10 * is an acceptable risk level for multiple contaminants. EPA
uses a 1 x 104 to 1 x 106 risk level as a "target range" within which to manage risk at Superfund sites.
secondary treatmentSecondary treatment follows primary treatment by using microorganisms to
remove suspended and dissolved organic matter. After the microorganisms have "eaten" the waste,
they clump together and settle to the bottom in a secondary clarifier tank. Chlorine is then mixed with
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the water to kill harmful microorganisms called pathogens. The chlorine is removed before the water
is discharged to the river.
semivolatile organic compoundsAn organic compound (carbon-containing) that does not typically
volatilize at room temperature.
sewageThe used water and solids that flow from homes and businesses through sewers to a
wastewater treatment plant.
sludgeThe settleable solids separated from water during wastewater treatment.
Superfund Amendments and Reauthorization Act of 1986 (SARA)Amendments to CERCLA
that were enacted on October 17, 1986.
Technical Assistance Grant (TAG)A grant program that provides funds for qualified citizens'
groups to hire independent technical advisors to help them understand and comment on technical
decisions relating to Superfund cleanup actions.
tertiary treatmentIn most cases, secondary treatment of wastewater is sufficient to meet effluent
standards. In some instances, however, additional treatment may be required. Tertiary treatment most
often involves further removal of suspended solids and/or removal of nutrients.
volatile organic compounds (VOCs)An organic compound (carbon-containing) that evaporates
(volatilizes) readily at room temperature.
wastewater treatmentA process by which wastewater is treated using a combination of physical,
chemical, and biological processes to produce cleaner water.
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Attachments
DEN/H/DA/WORDPWIN/JOI.WPD
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Attachment A
Metro's Methods to Calculate
Pretreatment Standards
DEN/H/DA/WORDPWIN/IOl.WPD
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PRELIMINARY
PROPOSED SELF-MONITORING REQUIREMENTS AND POLLUTANTS TO BE LIMITED BY PERMIT
FOR THE LOHRY SUPERFUND SITE DISCHARGE TO THE CITY OF AURORA AND THE METRO
DISTRICT
The permittee will be required to sample an initial batch for all monitored
parameters and submit the analytical results to Metro for approval to
discharge the batch and commence normal discharge. The permittee will then be
required to sample the continuous discharge for all monitored pollutants on
the first three consecutive days of discharge. If these samples are in
compliance for all parameters, the monitoring frequency will be reduced to the
frequencies identified below. Monthly and quarterly monitoring requirements
and frequencies will be reevaluated after the first twelve months of system
operation and adjusted accordingly. Yearly monitoring requirements will be
reevaluated after five years and adjusted accordingly.
If at any time monitoring data indicate the need for inclusion of a permit
limit for a pollutant not proposed to be limited, or the advisability of
increased monitoring for any pollutant, the necessary changes will be made to
the permit by the District as it deems appropriate.
Twenty-four hour flow composite samples must be collected for all pollutants
except, cyanide and volatile organics which must be grab samples. Lower
Explosive Limit (LEL) and discharge flow ("on/off") must be monitored and
recorded continuously. The continuous recording device on the effluent
discharge shall be installed and maintained so that all periods of discharge
flow and all interruptions of discharge flow are recorded. The explosion
hazard monitoring equipment shall be calibrated so as to read in units of %
LEL, and shall be installed so that the sensor is located no more than
eighteen (18) inches above the flow in the control manhole. The explosion
hazard monitoring equipment shall be further equipped so that, upon a reading
of 10% LEL or greater, all discharge to the sanitary sewer system shall be
automatically terminated. Qischarge may resume only after permission is
granted from the Metro District.
The listed pollutants must be analyzed by 40 CFR 136 methods and the method
detection limits must be equal" to or less than the value listed as the Metro
Method Detection Limit (MDL). Analytical results that are reported as less
than the detection limit shall be considered zero for compliance purposes. If
approved analytical procedures are improved and result in lower detection
limits, those detection limits will be incorporated into the permit.
Finally, the permittee will be required to develop a contingency plan
detailing all facilities and operating procedures used by the permittee to
prevent the accidental discharge of prohibited materials and other substances
to the POTW..
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PRELIMINARY
THE FOLLOWING CRITERIA WERE USED TO DETERMINE MONITORING REQUIREMENTS AND THE INCLUSION
OF SPECIFIC POLLUTANT LIMITS IN THE PERMIT:
Samples above
Samples above
Samples above
Samples below
Samples below
Samples below
Samples below
Criteria
proposed limit; detected in 10% or more of samples
proposed limit; detected in less than 10% of samples
proposed limit; values not confirmed
proposed limit; detected in 70%-100% of samples
proposed limit; detected in 40%- 70% of samples
proposed limit; detected in 10%- 40% of samples
proposed limit; detected in less than 10% of samples
Limit? Monitoring
Yes Monthly
Yes Quarterly
Yes Yearly
No Monthly
No Quarterly
No Yearly
No None
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PRELIMINARY
1,1-Dichloroethane
Monthly
4,580.00
5.00
1,1 -Dichloroethylene
Monthly
3.00
5.00
1,1,1 -Trichloroethane
Monthly
1,550.00
5.00
1,2-Dichloroethane
Monthly
58.00
5.00
1,2-Dichloroethene (trans)
Monthly
280.00
5.00
Arsenic (total)
Monthly
330.00
10.00
Benzene
Monthly
50.00
1.00
Carbon disulfide
Monthly
60.00
n/a
Chloroform
Monthly
73.00
5.00
gross Alpha
Monthly
To be
Determined
n/a
gross Beta
Monthly
To be
Determined
n/a
specific Radioisotopes
To be Determined
To be
Determined
n/a
Methylene Chloride
Monthly
1,993.00
5.00
Pentachlorophenol
Monthly
136.00
50.00
Phenanthrene
Monthly
1.40
10.00
Phenol
Monthly
22,813.00
10.00
Selenium (total)
Monthly
660.00
2.00
Tetrachloroethylene
Monthly
1,500.00
5.00
Toluene
Monthly
1,360.00
5.00
Trichloroethylene
Monthly
710.00
5.00
Vinyl Chloride
Monthly
0.30
5.00
Zinc (total)
Monthly
15,600.00
20.00
Silver (total)
n/a
2,900.00
0.20
1,2-Dichloropropane
Quarterly
78.00
5.00
Acrylonitrile
Quarterly
28.00
50.00
larbon Tetrachloride
Quarterly
30.00
1.00
Ethylbenzene
Quarterly
1,590.00
5.00
Xylenes
Quarterly
22,813.00
5.00
1,1,2-Trichloroethane
Yearly
92.00
5.00
-------
1 , 1 ,2,2-Tetrachoroethane
1 ,2,4,-Trichlorobenzene
1 ,4-Dichlorobenzene
2,4,5-T
4-Methyl-2-Pentanone (MIBK)
4-Methylphenol
4,4-DDD
4,4-DDE
alpha-Chlordane
Benzo(G, H, l)Perylene
Bis(2-Ethylhexyl)Phthalate
Cadmium (total)
Chromium (total)
Chrysene
Copper (total)
Cyanide (total)
Endrin
Ethylene Glycol
Lead (total)
Mercury (total)
Molybdenum (total)
Naphthalene
Nickel (total)
PCBs
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
Yearly
25.00
390.00
214.00
n/a
n/a
n/a
0.40
0.29
0.28
n/a
2,333.00
3,400.00
3,600.00
n/a
6,100.00
2,000.00
n/a
n/a
2,200.00
130.00
710.00
2,650.00
5,600.00
0.02
5.00
10.00
10.00
n/a
n/a
n/a
0.10
0.10
0.50
10.00
10.00
0.50
20.00
10.00
1.00
30.00
0.10
1,000.00
10.00
0.20
30.00
10.00
20.00
1.00
*For inorganic analyses the
lab limits are instrument
detection limits not MDL
-------
No Limit or Monitoring
Requirements:
1,2-Di bromo-3-Chlqropropane
1,2-Dibromomethane (EDP)
1,2-Oichlorobenzene
1,2-Dichloroethene (cis)
1,2,4,5-Tetrachl orobenzene
1,3-Dichlorobenzene
1,3-Dichloropropene (cis)
1,3-Dichloropropene (trans)
2-Butanone (MEK)
2-Chloroisopropyl Ether
2-Chlorophenol
2-Methylphenol
2,3,7,.8-TCDD
2,4-Dichlorophenol
2,4-Dimethylphenol
2,4-Dinitrophenol
2,4-D
2,4,5-TP
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2.,-Chloronapthalene
2,-Hexanone
2,-Methyl napthalene
3,3-Dichlorobenzidine
.4,-Chioro-3-Methylphenol
4,-Chloroaniline
4,-Nitroaniline
4,-Nitrophenol
4,4-DDT
Acenaphthene
Acetone (2-Propanone)
Aldicarb
Aldicarb Sulfonate
Aldicarb Sulfoxide
Aldrin
alpha-BHC
Aniline
Anthracene
-------
Benzole Acid
Benzo(A)Anthracene
Benzo(A)Pyrene
Benzo(B)Fluoranthene
Benzo(K)Fluoranthene
Benzyl Alcohol
Benzyl Butyl Phthalate
beta-BHC
Bis(2-Chloroethyl)Ether
Bromodi chl oromethane
Bromoform
Carbaryl
Carbazole
Carbofuran
Chlorobenzene
Chloroethane
Chloromethane
delta-BHC
Dibenzofuran
Di bromochloromethane
Dicamba
Diethyl Phthalate
Dimethyl Phthalate
Di-n-Buthyl Phthalate
Di-N-Octyl Phthalate
Dinoseb
Endosulfan I
Endosulfan II
Endosulfan Sulfate
Endrin Aldehyde
Endrin Keton
Ethylenedi bromi de
Fluoranthene
Fluorene
gamma-BHC
gamma-Chlordane
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Indeno(l,2,3-cd)Pyrene
Isophorone
-------
MCPA
Methoxychlor
Nitrobenzene
n-Nitroso-Di-N-Propylamine
n-Ni trosodi phenylami ne
Pentachlorobenzene
Ppropoxur
Styrene
Total Tribalomethanes
Vinyl Acetate
-------
Preliminary Lowry Limits Determination
Pollutant
1,1-Dlchloroethane
1,1-Dlch/oroethylene
Tjltl-Trichloroethane
1,2-Dichloroethane
1,2-DichloroetheneJtrans)
Arsenic
Benzene
Carbon Disulflde
Chloroform
Methylene Chloride
Pentachlorophenol ,
Phenanthrene
Phenol
Selenium
Tetrachloroethylene
Toluene
Trichloroethylene
Vinyl Chloride
Zinc
Silver
1,2-Dichloropropane
Acrylonitrile
Carbon Tetrachloride
Ethylbenzene
(D
Worker
Health/Safety
Sewer Cone.
(ug/L)
4560
3
1550
1050
280
60
410
2060
4370
1024000
1360
710
0.3
3620
(2)
Hazardous Air
Pollutants
Tot Plant Inf.
(Tons)
10
10
10
10
(3)
Water dual.
StdsJRBC
Plant Eft.
(ug/L)
810
0.044
200
0.12
100
101 21
10
10
10
10
10
0.15
4.1
0.28
0.0028
2560
750
1.6
0.019
0.16
1190
30
0.058
0.16
15901 10 j 680
(4)
Local
Limits
Ind. Discharge
(ug/L)
330
50
660
1500
15600
2900
(1)
Allowable Ind.
Discharge @
20
gpm
(ug/L)
4580
3
1550
(2)
Allowable Ind.
Discharge @
20
gpm
(ug/L)
22813
22813
22813
1050 22813
280 r
(3)
Allowable Ind.
Discharge @
20
gpm
(ug/L)
W
Allowable Ind.
Discharge @
20
gpm
(ug/L)
393750 «««
21 ' '
97222 """""
58 ,-
4861 1C ««.«
.................r , 330
,
60] 22813
410 *****************
2060
4370
22813
22813
1024000
22813
50
10208 r
94 **********«***
1993"" """"""
136 *****************
1.4 r
1 i"*-T"**T-*
1360
710
22813
22813
0.30 r*
660
1500
364583 ;' *
778 «
9 ;
15600
* ' ,* I 2900
3620 ,"""*
78 T
1190 28
30
78 " "
1590! 22813; 330556 ;*
Limit @
20
gpm
(ug/L)
4.580J
3.0 j
1,550
58
280
330 i
50
60
73
1,993
136
1.4
22,813
660
1,500
1,360
710
0.30
15,600
2,900 i
78
28 i
30
1,590
Page -1 of 2
-------
Preliminary Lowry Limits Determination
Pollutant
Xylenes
1 , 1 ,2-Trlchloroetnane
1,1,2,2-Tetrachoroethane
1,2,4, -Trichlorobenzene
1,4-Dlchlorobenzene
4,4-DDD
4,4-DDE
alpha-Chlordane
Bls(2-Ethylhexyl)Phthalate
Cadmium
Chromium (total)
Copper
Cyanide
Lead
Mercury
Molybdenum
Naphthalene
Nickel
PCBs
(D
Worker
Health/Safety
Sewar Cone.
(ug/L)
182300
1150
440
390
3550
1270
2650
5
(2)
Hazardous Air
Pollutants
Tot. Plant Inf.
(Tons)
10
-
10
10
10
10
10
10
(3)
Water Qual.
StdsVRBC
Plant Eff.
(ug/L)
10000
0.19
0.052
50
0.44
0.00083
0.00059
0.00058
L 4-8
620
0.000044
(4)
Local
Umits
Ind. Discharge
(ug/L)
3400
3600
6100
2000
2200
130
710
5600
(D
Allowable Ind.
Discharge @
20
gpm
(ug/L)
182300
1150
440
390
3550
1270
«***
2650
5
(2)
Allowable Ind.
Discharge @
20
gpm
(ug/L)
22813
22813
22813
22813
22813
22813
22813
(3)
Allowable Ind.
Discharge @
20
gpm
(ug/L)
4861111
92
25
24306
214
0.40
0.29
0.28
2333
301389
0.02
(4)
Allowable Ind.
Discharge @
20
gpm
(ug/L)
3400
3600
6100
2000
2200
130
710
5600
Limit @
20
gpm
(ug/L)
22,813
92
25
390
214
0.40
0.29
0.28
2,333
3,400
3,600
6,100
2,000
2,200
130
710
2,650
5,600
0.02
Page - 2 of 2
-------
EFFECT OF PROPOSED LOWRY SITE DISCHARGE ON METRO BIOSOLIDS QUALITY
Pollutant
"EQ" Biosolids
ug/g
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Zinc
Alpha, gross*
Beta, gross*
41
39
1200
1500
300
17
N/A
420
100
2800
N/A
N/A
Current
Metro Biosolids
ug/g
1.7
6
66
519
78
2.2
19
31
3.1
684
20
23
Maximum Addition
From Lowry
ug/g
0.3
2
3
5.
2
0.1
1
3
0.2 .
11
N/A
N/A
Maximum Metro
Plus Lowry
ug/g
2.0
8
69
524
80
2.3
20
34
3.3
695
N/A
N/A
Expected Addition Expected Metro
From Lowry Plus Lowiy
ug/g ug/g
0.1
0.01
0.004
0.04
0.02
0,0001
0.01
0.04
0.05
0.18
0.03
0.04
1.8
6
66
519
78
2.2
19
31
3.1
684
20
23
* Units are pCi/g
-------
COMPARISON OF PROPOSED LOWRY SITE DISCHARGE METALS WITH OTHER INDUSTRIAL DISCHARGERS
Pollutant
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Molybdenum
Nickel
Selenium
Silver
Zinc
Metro Limit
ug/L
330
3,400
3,600
6,100
2,200
130
710
5,800
660
2,900
15,800
Expected Actual Actual
Lowry Discharge Electro-plater "A" Electroplater "B"
ug/L ug/L ug/L
62
17
5
54
25
<1
6
76
126
6
258
55
49
210
237
1,186
<1
N/A
64
<1
1
2,455
2
911
14
26
<1
470
64
2
5
72
Actual
Coil Coater
ug/L
29
4
39
48
144
.49
30
23
Actual
Dye Manufacturer
ug/L
103
4
50
<1
1,128
-------
EFFECT OF PROPOSED LOWRY SITE DISCHARGE ON METRO EFFLUENT QUALITY (DISCHARGE PERMIT)
Permit Limit
Pollutant
Arsenic
Cadmium
Chromium
Copper
Cyanide
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Tetrachloroethene
Zinc
ug/L
50
2.23
11
24.6
30
13.1
400
0.4
184
8
1.4
5
219
Current
Metro Effluent
ug/L
<.50
<5.0
6.7
<30
45
<.20
<20
<2.0
0.20
<5.0
39
Maximum Addition
From Lowry
ug/L
0.002
0.1
0.06
0.06"
0.2
0.05
N/A
0.002
0.3
0.04
0.008
0.03
0.3
Maximum Metro
Plus Lowry
ug/L
<50
<5.0
6.8
<30
N/A
<.20
<20
<2.0
0.21
<5.0
39
Expected Addition
From Lowry
ug/L
0.0004
0.0005
0.0001
0.001
0.002
0.001
0.3
0.000002
0.003
0.007
0.00002
0.002
0.006
Expected Metro
Plus Lowry
ug/L
<50
<5.0
6.7
<30
45
<.20
<20
<2.0
0.20
<5.0
39
-------
EFFECT OF PROPOSED LOWRY SITE DISCHARGE ON METRO EFFLUENT QUALITY (STREAM STANDARDS)
Current
Standard Metro Effluent
Pollutant ug/L ug/L
Chloride 250,000 - 90,000
Sulfate 250,000 - 165.000
1,1-dichloroethylene 0.057 " <5.0
1,2-dichloroethana 0.4 <5.0
Benzene 1 <1
1,2-dichloropropane 0.56 <5.0
Naphthalene 620 <10
Pentachlorophenol 0.28 <50
Phenol 2,560 <10
1,1,2,2-tetrachloroethane 0.17 <5.0
Toluene 1,000 <5.0
1,2,4-trichlorobenzene SO <10
Trichloroethylene 2.7 <5.0
Vinyl Chloride 2 <5.0
Maximum Addition
From Lowry
ug/L
N/A
N/A
0.00002
0.005
0.001
0.006
0.17
0.004
2
0.0003
0.1
0.04
0.06
0.00001
Maximum Metro
Plus Lowry
ug/L
N/A
N/A
<5.0
<5.0
<1
<5.0
<10
<50
<12
<5.0
<5.0
<5.0
Expected Addition
From Lowry
ug/L
215
125
0.00002
0.005
0.001
0.002
0.001
0.004
0.1
0.0003
0.1
0.001
0.006
0.00001
Expected Metro
Plus Lowry
ug/L
90,000
165,000
<5.0
<5.0
<1
<5.0
<50
<10
<5.0
<5.0
<5.0
-------
Attachment B
Superfund Sites Sending Liquids to a POTW
DEN/H/DA/WORDPWIN/IOI.WPD
-------
SITE NAME
W CREOSOTE WORKJ
kMO
ISLINGTON 8LENOIMG I PACK.
BELL IUM3ER 1 POLE
3RUNSWICK NAVAL AIR $TN
:ENTRAL LANOFIH
:HEM CENTRAL
ClMARRON MINING
CONKLIN DUMPS
TS PRINTEX
LLMORE WASTE
AIRFIELD COAL GASIFICATION
CX
IE LOS BROOK
% WIRING
OLO COAST OIL
SOLDEN STRIP SEPTIC
IAYTORO BRIDGE ROAD
HPPSROAO
1AOCO-HUGME5
(*L LANDFILL
CEARSAROE METALLURGICAL CORP
CENTWOOOLOFL
COPPERS CO
LOCATION
PENSACOLA. FL
SUNNYVALE CA
ARLINGTON TN
NEW BRIGHTON MN
BRUNSWICK. ME
JOHNSTON. Rl
GRAND RAPIOS
CARRIZOZO. NM
CONKUN. NY
MONTANVIgW. CA
GREER. SC
F AIRFIELD. IA
STATESVILLE. NC
ASMTABULA. OH
JUANA DIAZ. PR
MlAM:. FL
SIMPSON. SC
ST. CHARLES. MO
JACKSONVILLE. FL
BELMONT. NC
KALAMAZOO. Ml
CONWAY. NH
KENTWOOD. Ml
CHARLESTON. SC
t£A
REGION
4
9
4
:
i
i
s
e
2
g
4
7
4
S
I
4
4
7
4
4
S
1
S
4
DATE Ol
ess
rWa
»-!1.«l
&V28.91
\zii.v:
8MSS2
SM7.94
9OOT1
4/3W3
J/»9t
rani
v»ta
mm
unit)
VXHK
9OCVU
9/11/87
B/1291
13O»n
V30S
9/77/90
VTtrx
V&M
irawi
V2»D5
COMTACT
MARK FITE
RICHARD PROCUNIER
OERE- MA TORY
OARRELL OWENS
BOB LIM
JOHN COUROER
TIM PRENDOVIL
DON WILLIAMS
ARNOLD BERNES
RICHARD PROCUNIER
RALPH HQWARO
BRUCE MORRISON
KENMAU.ORY
TERESEVANDONSEL
CAROL 'NE KWAN
BRAD JACKSON
O2ELLE BENNETT
STEVE AUCHERLONIE
KEN LUCAS
MIKE TOWNSENO
PABLO VALENTENE
OM STEELE
DAVID LANIER
KELLY SINGER
JENO TO
porw
NO
NO
NO
NOT
IMPLEMENTED
YES ground
our
NO
YES -ground
«*»r
YES-gnuu
YESLMlMt
YES-arawl
NO
YES -grand
«»
NOT
IMPLEMENTED
NO
NO
NO
YES -grant
an^nc
Ground Wfltr. eyand* Sod. voafUt ind Mffli-
mutileonjanei PCSr rargma
Ground w««/. utavfi: M»y men. raatm
Ground w«tr «KM orgnc ampountt. hwvy
mMM find, copper) Sat* MM. caaxr
Ground Wur PAHi (intn-v^-. pym) So>
vaUk argnc oompaundl (t>nn>. taunt.
yam) loid. mtrcury. eyind* un»
Ground Wazr. nmy mmtt (cnramum. caamum.
wa. mi soamna. SwfeeirSinumn Sob
rmvymHHi
Ground Wur MWm orgmc oonpound> (vn|<
J. bmzw)
SMmem Xuvr mmn (cnrorhum. tod. nclur).
polyiMonriMd ftBnery. Sol: hMvy nooM. «eable
Wmr VOUM. aytns conpoundi. hwy mmK
Grourvl 'JVur voUDl* orgmK oompound*
nck«4. vb& Oust SuHtct W«tcr voMk orgmc
Ground Water. Sod. Lucrgrtt vomit organic
compounds hrtvy metals (afMrac. neJcd)
Sod. Ground Water, and Drainage Otcrv*
numerous DoNnuclear aromatic nvdroonxms
TYPE Of DISPOSAL
LAND APPLY
NO SUCH LISTING OF POTW
STILL ACCUMULATING J
COMPOST
INCINERATED ON SITE
LAND APPLY
STAY LME TO FARMERS IN SOME CASES
NCINERATED ON SITE
LAND APPLY
NCINERATED ON SITE
LANDFILL
NOT ENOUGH TO DEAL WITH YET
LANDAPPL/10MOS OUT OF YEAR
NCINERATED ON SITE
LAND
APPLY
N
N
N
N
Y
N
N
N
N
N
N
Y
Y
N
N
N
N
Y
N
N
N
N
Y
N
-------
SITE NAME
COPPERS CO
LEXINGTON CO
JPARI LANDFIl .
BIACGILUS t GIBBS
tAUORY CAPACTOR
ICGHAW EDISON
MAM! COUNTY INCtN.
IICHICAN DISPOSAL
HOWEST MANUFACTURING
IINOT LANDFILL. NO NOD9809SflM«
HONSANTO CO
IUSKEGON CHEM.
J.W. MAUTME
WTL PRESTO INO
IEW HANOVER CO AIRPORT BURN PIT
IIAGARA COUNTY REFUSE
IIAGARA MOHAWK
'ARA-CMEM
IEDWINO CARRIERS
ISR CORP
LOCATION
GALESBURG, 11
CAVCE. SC
MANTUA TWNSH". NJ
NEW BRIGHTON MN
WAYNESBORC TK
CENTERVILLE. IA
TROY. OH
KALAMAZOO.M1
KEUOGG. IA
AUGUSTA. OA
WHITHALL. Wl
PPLETON. Wl
AU CLAIRE. Wl
WILMINGTON. NC
NIAGARA CO.. NY.
SARATOGA SPGS
SIMPSONVIU£. SC
SARALA«tf>.AL
DALLAS, n
EPA
REGION
:
4
2
5
4
7
5
9
T
4
5
:
s
4
1
t
4
4
t
DATE OF
B2B
678-89
VSM
6V1S/92
123142
*2M<
B/j*«3
ovxro
tnmi
vnna
I2f/9l
warn
Wi/94
vxni
mm
viva
V3Sfl6
vum
12T1SJ82
2/7OT6
CONTACT
FREO NICA
TERRY TANNER
FRED CATANEO
OARREU OWENS
ROBERT MORRIS
PAULETTA FRANCE-ISETTS
TONY RUGTER
TIM PBENDOVll
OIANE EASLEY
JOHN UCKEWEN
LONNIE LEE
BSSICA cARRtrr
STEVE PHON
BEVERLY HUDSON
MIKE NEGREUI
MARIA JON
TERRY TANNER
MIKE ARNETT
CARLOS SANCHEZ
MNOTO
POTW
NO
NO
YESlMtfttt
YES-ywM
NO
NOT
IMPLEMENTED
YES-ptuM
MMr
NO
NO
YES-graund
MUr
YES-TDuna
YES-graund
YES-gmn)
Mtf
NO
NOT
UPLEMEMTCO
YES
NOT
IMPLEMENTED
NO
NOT
MPLEMENTEO
NO
NAME OF rOTW
MANTUA
NEW BRIGHTON POTW
TROY WATEF* TRMT. PLNT
VERY SMAU SITE: SLUDGE TO LANDFILL
WHATEHAU AREA POTW
CITY Of APPLETON
N TANAWANOA
SARATOGA SEWER DIST.
CONTAMINANTS Of CONCERN
Air vattile orgmc compounds Ground WMcf .
SurtK* WMr. SMmm vajufc onjanc
cdmpounOi. t**.; mate (vunc. Onmum lud)
Sot', mlifric OfQimc ttuiniJUUnd*. hvlvy (IMUIA.
onndaa LMCMII icuat aytnc
PMnpk
Ground W««r. S«trn>n. Sob) pOycyckc
mobjb) ttnonK. borwn. eadrmjrn) 54UiomO
MBtlCttlM, PCBl SO4I~ VOOHV OTQMVC LWIVOUfldl.
p««Hrtn, hMvy IMOU (munc. tad. odmun.
cnramum)
Ground W««r Ovrtnnt. Toluene. H«iog«n««c
AlftponBDCI, liwiyji w, Phwuw vnd Compaunoi.
Po^cyclK Anxmc Hyaroorooni. (PAHt).
Acoton*. ArDCtor 1253
Ground Wlttr irvrac
JMjlufUdll
Ground Wctir, Sal' MOMOI* orgme compounds,
nMvy rnttilKchrorrun)
Sail. Ground W«hr. Surtao Wwr. S4ttrr«nt
«OM* orojTK oompoundt. tornHMKill*.
pntadM. hnvf men*
TYPE OF DISPOSAL
INCINERATED ON SfTE
INCINERATED ON SITE
LANDFILL
LANDFILL
LAND APPLY
NO SLUDGE FROM SITE (ASKED HIM 3 TIMES)
LANDFILL
LANP
APfLY
N
S
N
N
N
N
N
N
N
N
N
Y
N
N
N
N
N
N
N
-------
SITE NAME
SAND CREEK SITE. OU 15 («On ar« Holly
jnofi»COD88071T9S3
SCHUYLMLL METAL
SEYMOUR RECYCLING
5OUD STATE CIRCUITS
ItLEOYNE SEMCONDUCTOR
riNKHAM OARAGE
fRI COUNTY/ELGIN LANOFIU
INFTED CHROME PRODUCTS
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VASATCH CHEMICAL
WASTE INC.
VOOOSTOCK UUNI.
LOCATION
PLANT C;TY. FL
SEYMOUR. IN
REPUBLIC. MO
MONTANVIEW. CA
LONDONDERRY. NH
ELGIN. IL
CORVAUJS. OR
ALBANY. OA
PATUXENT RIVER. MO
SALT LAKE. UT
VALLEY BARK. MO
SALT LAKE. UT
MICHIGAN CITY. IN
WOODSTOCK. IL
EPA.
REGION
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DATE Of
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12/20/91
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CONTACT
CALLO JACKSON
JOE HOSIER
STEVE AUCH£RLONIE
RICHARD PROCUNIER
JIM OILORENZO
TIM PRENOOVIL
AL GOODMAN
ROBERT POPE
ANDY SOCHANSK)
PAULA SCHMrrTTjlEL
STEVE AUCHERLONIE
RNA ACHESON WATERMAN
DION NOVAK
OMN O'GRAOY
SEND TO
POTW
YES-grautf
wit«r
YES -ground
wvrr
YES-gnuiil
w«Mr
YES -ground
M!«r
YES-grauna
wmr
YES -ground
NO
YES -ground
Mr
YJS-ground
MftflnclHtt
YES-ground
metals (Mad. cnromu/n.
sulral* ammonbl) S^Dml. Surface Water.
Swintms itaa
Ground Water roan* organic compountfi.
mvt. mangantse) Scxtl volaue organic
cornpound* haavy :netatt (beryiiu/n]
Ground Water voiaT'-e organc compound* (TC£.
mcfnvie^e ctitonot cruorolorm)
Soil. Ground Water wouu* oroanic comoounds
Ground Water. Surface Water. Son volatile organic
Sadmenta,. So*. Surface Water. Ground Wattr
Sot Gat. wolaUa orgarvc cdmpounda Ground
Water votaue organcm. norganca Surface Wrier
ntaMeorganiea
^Monxmeiie. 4.4-OOT. Aroor-l MO. torgano.
Sludge. Seaman. Surface) Water paalicotl.
orgenccompmnn cyende Surface Son. lew.
MCCaJO Gmaid Water. vdlaHe orgarvc
flfflpoulde, (benzene. Mjfene. Idkiene. a|4ine.
cyejneJe)
Ground Water ₯OUai« and aerK-vaalj* organc
ompounda. "organics
TYPE OF DISPOSAL
INCINERATED OMSI'c
LAND APPLY
LAND APPLY
INCINERATED ON SITE '
LAND APPLY
LAND APPLY
UNKNOWN
LAND APPLY SOME/REST TO LANDFILL
LAND APPLY
LANO
APPtT
N
Y
V
N
Y
N
Y
N
N
N
N
N
Y
N
-------
Attachment C
A Detailed Assessment of the Radioisotopes Data for Lowry Landfill
H:\DA\WORDPWIN\092.WPD
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Introduction
Because of concerns over the possible presence of radioactivity in ground water at the Lowry
Site, an additional review of the available radionuclide data in the Lowry Site ground-water
database has been conducted. This review has focused on the radionuclides that could be present
if material originating at the Rocky Flats Plant had been disposed of at the Lowry Site at some
point in the past. The purposes of this review and data evaluation are: 1) to determine if the
ground water potentially addressed by the Second ESD has been adequately characterized for
radionuclides, and 2) if characterization is adequate, to determine if potential radionuclide
concentrations have any health or environmental exposure impacts if the proposed Second ESD
is implemented.
The man-made radionuclide isotopes that could have originated from weapons manufacturing at
Rocky Flats were investigated. These isotopes include:
Americium-241
Neptunium-239
Plutonium-238
Plutonium-239/240
Plutonium-241
These isotopes, together with the nuclear fission products, cerium-141, cerium-144, cesium-137,
cobalt-60, strontium-85, strontium-90, and tritium, are reported present in our environment
because of atmospheric fallout that resulted from above-ground nuclear weapons testing
conducted between the late-1940s and late-1960s. However, it should be noted that tritium and
the isotopes of cerium, cesium, cobalt, and strontium could not have originated from Rocky
Flats, nor any other mining, milling, or manufacturing complex, because they are products of
nuclear fission (i.e., products of a nuclear reaction, or detonation), and no fission testing was
conducted at these sites. Other radionuclides, such as uranium, thorium, and their associated
daughter products (i.e. isotopes of radium), are naturally occurring, and in the Rocky Mountain
region, generally are found at relatively high background concentrations due to the regional
geology. For these reasons, and because the commenter has focused on the man-made isotopes
that could be present above background levels at the Lowry Site, this attachment presents a
detailed analysis of americium, neptunium, and plutonium.
A listing of americium and plutonium isotopic data from Lowry Site ground water was included
in "Evaluation of Data Quality and Occurrences of Transuranic Radionuclides in the Shallow
Groundwater and Subsurface Liquids and Deep Groundwater Operable Units, Lowry Landfill"
(HLA, 1992b). Neptunium data in the sitewide ground-water database, and an additional
radionuclide sampling event that was conducted in 1994 at Well MPZ-1, were also evaluated.
All of these data were reevaluated for purposes of assessing the validity of the data, as measured
against the parameters of precision and comparability. Next, the data were assessed for usability
with respect to practical parameters such as a comparison of detections in upgradient wells
compared to waste pit wells where contamination would be most expected. In addition, an
evaluation of isotopic ratios that would be expected if a radionuclide were really present, was
also performed.
H:\DA\WORDPWIN\092.WPD
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Regarding the validity of the data, the following definitions are presented for general
information:
Counting Errors: An error in the number of disintegrations accumulated over
the designated count timeframe. This variable was used to assess the precision of
the laboratory reported value; the greater the counting error, the less precise the
reported value.
Recounting: The process of confirming or reevaluating the number of
disintegrations over the designated count timeframe. This process was used for
quality assurance, instrumentation calibration, and data verification.
Blank Contamination: A quality assurance mechanism that consists of a
quantitative assessment of sample collection and analytical processes to assess the
potential for cross-contamination and/or counting error originating from
laboratory instrumentation or analyst.
Confirmatory Sampling: A quality assurance mechanism to qualify the presence
of a detection, and if present, to quantify the detected concentration. This variable
was very important in this assessment because, due to the uncertainties of the
sampling and analytical protocol, it provided a quantitative comparison of results.
A duplication of results was essential to establishing the comparability of a
sample location over time.
Reporting Limit: Limit of detection as required by contract or instrumentation
parameters (i.e. minimum detectable activity, count time, sample size, etc.). For
purposes of this assessment, this variable was used to assess the sensitivity of the
analytical procedure. It was also used to assess the comparability of the analysis
to EPA-specified protocol.
Americium, neptunium, and plutonium are discussed separately in the following sections.
Radionuclide Data
Americium 241 (Am-241)
Upgradient Ground Water. Ground water was analyzed for americium-241 at eight
background ground-water locations. Americium-241 was not detected in well B-520. In another
well (B-519), americium-241 was not detected at a reporting limit of 4.0 pCi/L; but was detected
at a lower detection limit of 1.8 pCi/L +/- 0.4 pCi/L. In the remaining six wells (MW-003, MW-
004, MW-005, MW-22BU, U-509 and U-510), americium-241 was detected at concentrations
ranging between 1.3 pCi/L +/- 0.3 pCi/L and 13.0 pCi/L +/- 6.0 pCi/L. No additional sampling
was conducted to confirm detections at these upgradient locations.
Waste Pits. Waste pit liquids were analyzed for americium-241 at twenty-one waste pit
locations. Americium-241 was not detected at fifteen locations. Americium-241 was detected in
H:\DA\WORDPWIN\092.WPD C-2
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one sample, but when recounted showed a non-detection, meaning the presence of americium-
241 could not be confirmed. The remaining five samples showed detections ranging between
0.30 pCi/L +/- 0.20 pCi/L, and 3.6 pCi/L +/- 1.8 pCi/L. No additional sampling was conducted
to confirm detections at these waste pit locations.
Source Area Weathered Dawson. Ground water was analyzed for americium-241 at two
locations in the weathered Dawson in the source area (GW-111 and GW-112). Americium-241
was not detected in two sampling events at GW-111. Americium-241 was detected in GW-112
at 94 +/- 80 pCi/L in the first sampling event, but was not detected in the second event.
Downgradient Weathered Dawson. Ground water was analyzed for americium-241 at seven
downgradient weathered Dawson locations. Americium-241 was not detected at six of the
locations. Americium-241 was not detected in the seventh location (MW02-AD) during one
event, but during the second event, was detected at 0.22 pCi/L +/- 0.17 pCi/L.
Unweathered Dawson. Ground water was analyzed for americium-241 at ten unweathered
Dawson locations. Americium-241 was not detected at eight locations. Americium-241 was
detected at two locations as follows:
Well GW-104 showed a non-detection at 1.0 pCi/L and a detection at 0.26 pCi/L
+/- 0.24 pCi/L
Well MW11-BB showed a non-detection at 0.5 pCi/L and a detection at 10.0
pCi/L +/- 1.0 pCi/L. Americium-241 was also detected in the field blank for this
event
Deep Ground Water. Ground water from four deep ground-water wells was analyzed for
americium-241. Americium-241 was not detected in two of the wells for two sampling events.
Americium-241 was detected and not detected in the other two wells as follows:
Well GW-103 reported a detection of 0.66 pCi/L +/- 0.39 pCi/L, and a non-
detection of 0.42 pCi/L
Well GW-113 reported detections in both samples (0.31 pCi/L +/- 0.23 pCi/L and
0.57 pCi/L +/- 0.26 pCi/L), but recounts of these two samples showed non-
detections at 0.12 pCi/L and 0.07 pCi/L
Summary and Conclusions for Americium-241. Of the fifty-two wells sampled for
americium-241, americium-241 was not detected in thirty-three wells, and eight showed initial
detections, but when recounted or resampled and analyzed, the recounting or resampling showed
non-detections.
Americium-241 was detected in eleven wells. Of these eleven, six were located upgradient of the
Lowry Site, and five were located in waste pits. Most of the concentrations reported for the
upgradient samples exceeded those of the waste pit samples. In addition, americium-241 data for
these eleven wells are considered inconclusive because:
H:\DA\WORDPWIN\092.WPD C-3
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Well B-707 (0.95 pCi/L +/- 0.52 pCi/L) with no confirmatory sample
Well B-709 (0.82 pCi/L +/- 0.38 pCi/L) with no confirmatory sample
Well GW-101 (0.17pCi/L+/-0.15pCi/L, and a recount of 0.16 pCi/L+/-0.12
pCi/L; no confirmatory sampling was performed
Deep Ground Water. Plutonium-239/240 was analyzed in seven deep ground-water wells.
Plutonium-239/240 was not detected in five wells. Plutonium-239/240 was detected, and
subsequently not detected, in the other two wells (C-702 P3 and C-702 Ql).
Summary and Conclusions for Plutonium-239/240. Plutonium-239/240 was not detected in
fifty-one of the seventy-seven wells sampled, and twenty wells showed initial detections, but
through recounting or resampling, these detections could not be confirmed.
Plutonium 239/240 was detected in six other wells. These are located in the waste pits (I),
source area weathered Dawson (2), and unweathered Dawson (3). However, plutonium-239/240
data for these six wells are inconclusive because:
Plutonium-239/240 was detected in two performance evaluation samples and one
laboratory blank.
High counting errors (ranging from 20 percent to 88 percent) were reported in the
sample results.
Three of the wells are unweathered Dawson wells that, to date, have shown no
evidence of even the most mobile solvents disposed at the Lowry Site. By
comparison, plutonium, when in contact with fine-particle soils such as clay,
becomes immobile, and is therefore highly unlikely to have migrated vertically
more than 50 feet into the unweathered Dawson. Transport of plutonium-239/240
a vertical distance of 50 feet is estimated to take approximately 67,000 years.
In the eighteen wells where water quality data from the March, 1988 through July
1989 sampling events'showed detections of plutonium 239/240, later sampling
events showed non-detections in eleven of the twelve wells resampled.
No confirmation sampling was conducted at these wells.
Based on these observations, and the absence of plutonium 239/240 in seventy-one of the
seventy-seven wells sampled, the presence of plutonium-239/240 in ground water is considered
questionable.
Plutonium 241 (Pu-241)
Upgradient Ground Water. Plutonium-241 was analyzed in eight upgradient locations.
Plutonium-241 was not detected in six of the wells. Plutonium-241 was detected in B-520
during an initial sampling event at 78.0 pCi/L +/- 40.0 pCi/L, but in a subsequent sampling event,
showed a non-detection at a reporting limit of 25.0 pCi/L.
H:\DA\WORDPWIN\092.WPD C-6
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Waste Pits. Plutonium-241 was not detected in any of the 14 waste pit wells sampled.
Source Area Weathered Dawson. Plutonium-241 was analyzed in fourteen source area
weathered Dawson wells. Plutonium-241 was not detected in nine locations. Plutonium-241
was detected in the remaining five wells (B-704, B-710, U-503, U-704, and U-706). No
confirmatory sampling was performed on these wells.
Another observation can be made of the plutonium radiochemical data from the wells that
showed detections of plutonium-241. The radionuclide distribution by mass for weapons-grade
plutonium is as follows: plutonium-238 at 0.01 percent; plutonium-239 at 93.9 percent;
plutonium-240 a.t 5.8 percent; and plutonium-241 at 0.36 percent. Thus, pIutonium-239/240
accounts for roughly 99.7 percent of the plutonium used in weapons manufacturing and testing,
while plutonium-241 accounts for only 0.36 percent. Secondly, the half-lives of these plutonium
isotopes are as follows: plutonium-238 at 86.4 years; plutonium-239 at 24,390 years; plutonium-
240 at 6,580 years; and plutoniurn-241 at 13.2 years. Thus, plutonium-239/240 will remain in its
isotopic form for thousands of years, while plutonium-241 will rapidly decay toward americium-
241 in only 13.2 years. Together, these two factors indicate that plutonium-239/240 should be
significantly more prevalent in the environment than plutonium-241. Applying this logic, a
comparison of isotopic ratios of plutonium-241 to plutonium-239/240 for the wells in which
plutonium-241 was detected was performed. In all of the five wells, the isotopic ratios were
opposite what one would expect them to be. More specifically, plutonium-241 in each well was
reported at concentrations significantly greater that plutonium-239/240 for the same well. Just
the opposite should occur if the detections are real.
Downgradient Weathered Dawson. Ground water from seven downgradient weathered
Dawson wells was analyzed for plutonium-241. Plutonium-241 was not detected in six of the
, wells. Plutonium-241 was detected in well MW23-WD at 18.0 pCi/L +/- 11 pCi/L in one
sample, and not detected to a reporting limit of 50.0 pCi/L in another sample. It should also be
noted that plutonium-239/240 was not detected in this well (detection limits down to 0.05 pCi/L),
indicating an anomalous isotopic balance. Finally, this well had an average gross beta activity of
only 6.8 pCi/L; considerably less than the detected plutonium-241 value.
*
Unweathered Dawson. Eleven wells were analyzed for plutonium-241; nine showed non-
detections. The two wells showing detections included:
Well MW-001 showed a detection at 14.0 pCi/L +/- 8.0 pCi/L. This well also
reported non-detections at 70.0 pCi/L, 120.0 pCi/L, and 19.0 pCi/L. No
plutonium-239/240 was detected in this well (detection limits down to
0.07 pCi/L). It also had a gross beta value of only 13.0 pCi/L. This well is
located offsite.
MW-1 IBB reported an estimated detection of 33.0 pCi/L +/- 13.0 pCi/L and a
non-detection of 50.0 pCi/L. No plutonium-239/240 was confirmed in this well
(down to detection limits of 0.80 pCi/L). The average gross beta for this well was
only 12.4pCi/L.
H:\DA\WORDPWIN\092.WPD C-7
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Deep Ground Water. Ground water from six deep ground-water wells was analyzed for
plutonium-241. Plutonium-241 was not detected in five locations. The only detection was
reported in well C-702 P3 at 24.0 pCi/L +/- 12.0 pCi/L. It was not confirmed. In addition,
plutonium-239/240 could not be confirmed in this well (down to detection limits of 0.30 pCi/L).
Finally, the average gross beta for this well was only 14.5 pCi/L.
Summary and Conclusions for Plutonium-241. Ground water from sixty wells was analyzed
for plutonium-241. Forty-nine showed non-detections, and five showed initial detections, but
through recounting or resampling, the detections could not be confirmed.
Plutonium-241 was detected in six wells. These are located in source area weathered Dawson
(5), and deep ground water (1). However, plutonium-241 data for these six wells are
inconclusive because:
When considering the isotopic balance between plutonium-241 and plutonium-
239/240, the balances are inconsistent with what would be expected in the
environment. Specifically, the ratios imply that plutonium-241 is considerably
more prevalent in the environment than plutonium-239/240. This is not correct.
None of the 14 wells completed in waste pits detected plutonium-241; if it were
present at the Lowry Site, one would have expected it to be in the waste pits.
Plutonium-241 is reported to be detected in a deep well beneath the separation
layer. Neither this well, nor any other well beneath the separation layer, has to
date shown any evidence of even the most mobile solvents buried at the Site. By
comparison, plutonium, when in contact with fine-particle soils such as clay,
becomes immobile. Transport of plutonium-241 from the ground surface to the
top of the screened interval of this well will take an estimated 116,000 years.
No confirmation sampling was conducted at these wells.
Based on these observations, and the absence of plutonium-241 in fifty-four of the sixty wells
sampled, the presence of plutonium-241 in ground water is considered questionable.
Summary and Conclusions
To address the potential impact of radionuclides on the proposed amendment to the Lowry Site
ROD, an additional detailed evaluation of the radionuclide data from the Lowry Site ground-
water database was performed as discussed in the previous sections. This assessment was based
on the sitewide ground-water quality database that contains more than 2,900 records of speciated
radionuclide data. In addition, this database contains another 933 records of gross alpha and
gross beta data for ground water. EPA believes that this body of data provides adequate
characterization of the Lowry Site with respect to assessing the potential radionuclide impacts
associated with the proposed ROD amendment.
The conclusions from this assessment are:
H:\DA\WORDPWIN\092.WPD C-8
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Man-made radionuclides that could have originated from Rocky Flats and been
disposed of at the Lowry Site are limited to americium-241, neptunium-239,
plutonium-238, plutonium-239/240, and plutonium-241. None of these
radionuclides could be confirmed present in ground water beneath the Site.
Man-made radionuclides that might be present in the ground water that might be
pumped to the POTW are represented by wells GW-111, GW-112, and MPZ-1.
No man-made radionuclides were confirmed present in these wells.
Based on these conclusions, EPA believes that implementation of the Second ESD will not cause
any adverse impacts to humans or the environment from radionuclides in ground water at the
Lowry Site.
H:\DAWORDPWIN\092.WPD C-9
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Attachment D
Process for Developing the Final Version of the List of COCs
to Be Included in the Pretreatment Discharge Permit
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The Worker Health and Safety Based Discharge Screening Levels listed in Appendix B of the
"Draft Evaluation of the POTW Treatment Option"(Parsons ES, 1996) are preliminary. The
screening levels should not be considered the final version of the list of contaminants of concern
(COCs) that will be included in the Pretreatment Discharge Permit, nor as the final health and
safety-based discharge levels. Development of a final list of contaminants and allowable
discharge limits will be based on a four-step process. This process will allow a complete review
of all available physical, chemical, and toxicological information for the COCs, and will allow
development of pretreatment discharge levels that are protective of worker health and safety.
This process involves:
Step 1: Use of EPA Calculated Discharge Screening Levels: Appendix B of the EPA
"Guidance to Protect POTW Workers from Toxic and Reactive Gases and Vapors" (EPA,
1992b) provides a table listing gas/vapor toxicity-based discharge screening levels for commonly
encountered chemicals. The screening levels presented in this table have been incorporated into
the "Draft Evaluation of the POTW Treatment Option" (Parsons ES, 1996).
The calculation of the discharge screening levels is based on the threshold limit value (TLV) for
a specific chemical. The TLV is the airborne concentration of a particular substance to which the
"average worker" may be exposed without adverse effects. TLVs are set by the American
Conference of Governmental Industrial Hygienists (ACGIH). There are a number of
conservative assumptions concerning the "average worker" that are incorporated into the setting
of a TLV, including:
The worker is exposed to the substance throughout his or her entire occupational lifetime
- 47 years (age 18 to 65)
He/she works 40 hours each week
Workers vary in susceptibility according to physical condition and lifestyle
The numbers developed in the EPA guidance rely on chronic TLVs for development of the
discharge screening levels. Chronic TLVs are generally lower than acute TLVs, therefore, use of
these values ensures that acute TLVs are also being addressed.
*
It should also be noted that the discharge screening levels calculated per the EPA guidance do not
take into account any dilution of the chemicals with other discharges into the sewer system.
Therefore, the discharge screening level is based on an assumption of a worst case exposure
scenario (i.e., no dilution takes place between the point of discharge and the point of potential
exposure.)
Step 2: Calculation of Discharge Screening Levels for Additional COCs: The EPA
guidance presents discharge screening levels for approximately 50 chemicals. It also presents a
methodology for calculating discharge screening levels for other chemicals not presented in the
guidance. Step 2 will involve calculation of discharge screening levels for all COCs for which
the EPA guidance has not already calculated a value, and for which the required physical and
toxicological information exists (i.e., all chemicals for which TLVs are available and for which
Henry's constants exist or can be calculated). Step 2 will also involve a review of the values used
I:\DA\WORDPWJN\09I.WPD
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to calculate the TLVs presented in the guidance. Updated TLVs will be incorporated into the
screening level calculations where such information exists.
The EPA methodology is based on the TLV for a chemical and on its volatility. A chemical's
volatility is based on its solubility in water and its vapor pressure. A chemical dissolved in water
will, over a sufficient residence time, reach an equilibrium between the concentration of chemical
in water and the concentration in air. This equilibrium can be closely approximated by Henry's
Law, which states that, in a closed system, the concentrations of the liquid and vapor phases are
related by a constant. This constant is used to calculate the discharge screening level based on
the TLV for each chemical. Based on the chemical's solubility in water, formula weight, and
vapor pressure, it is possible to calculate the Henry's constant for a chemical if one is not
available in the literature.
It should be noted, however, that the EPA methodology makes several simplifying assumptions,
including:
Temperature is constant (the Henry's Law constant is affected by temperature)
Air flow is assumed to be negligible (increased air flow would tend to reduce the actual
concentrations and prevent the system from reaching equilibrium)
Rate of volatilization is instantaneous (the equilibrium concentration is the maximum that
can be achieved under a given set of conditions; the actual levels would be lower if the
system has not had time to reach equilibrium; the time required to reach equilibrium is
determined by the volatilization rate)
The Henry's constant is not affected by other constituents in the wastewater
For the most part, these assumptions will introduce conservative safety factors into the
calculations.
Step 3: Evaluate Effects of Exposure to Mixtures: Step 3 will involve an evaluation of the
potential additive and synergistic effects caused by exposure to multiple chemicals. The EPA
guidance presents a methodology for estimating the potential vapor toxicity from mixtures of
contaminants. The EPA methodology assumes knowledge of the actual contaminant discharge
levels; therefore, it will be necessary to develop reasonable estimates of actual contaminant levels
in order to develop exposure limits based on mixtures. Toxicological information for all COCs
will be examined to determine the target organ(s) of each chemical and to identify chemicals that
may act synergistically. Chemicals that affect the same organ or systems will be grouped and
discharge limits will be calculated to prevent an unacceptable risk based on the sum of the
potential exposures.
Step 4: Development of Actual Exposure Scenarios: Step 4 will involve development of
appropriate exposure scenarios to more accurately assess the potential for worker exposure.
Total exposure is dependent on two parameters: concentration of contaminants at the point of
exposure and the length of time during which the receptor is exposed. Site-specific information
will be developed to more accurately determine these two parameters. Administrative,
engineered, and personal protective controls will be considered during this step to more
accurately estimate potential concentrations to which workers may be exposed. Concentrations
H:VDA\WORDPWIN\09I.WPD D-2
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of contaminants at the point of exposure could be influenced by a number of factors, including,
but not limited to, the temperature of the discharge, air flow through the exposure location, and
dilution with other discharges. Duration of exposure could be influenced by occupation-specific
parameters such as time spent within a particular area or performing a specific task. Policies and
procedures employed by Aurora and Metro will be incorporated into the exposure scenarios.
H:\DA\WORDPWIN\091.WPD D-3
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Attachment E
Technical Evaluations
DEVH/DAAVORDPWIN/10I.WPD
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Technical Evaluation of Proposed Ground Water Treatment
and Disposal Alternatives for the LowryLandfill Site
DEN/H/DAAVORDPWIN/IOI.WPD
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Technical Evaluation of Proposed Ground
Water Treatment and Disposal Alternatives
for the Lowry Landfill Superfund Site
Introduction
This document supplements the proposed Explanation of Significant Differences (ESD), for the
Lowry Landfill Superfund Site (Site) in Arapahoe County, Colorado. New information has been
submitted to the U.S. Environmental Protection Agency (EPA) and the Colorado Department of
Public Health and.Environment (CDPHE) pertaining to the treatment component of the remedy
for contaminated ground water. This document summarizes the proposed remedial design
alternatives for ground-water treatment, analyzes the remedial design alternatives against the
nine EPA criteria, and selects a preferred ground-water treatment remedial design.
Ground-Water Treatment and Disposal Remedy
The March 10,1994 Record of Decision (ROD) for the Site specifies that the remedy for ground-
water treatment is "design and construction of a new ground-water treatment plant unless it can
be demonstrated through pilot-scale testing during the RD that the existing ground-water
treatment plant can effectively treat the more highly contaminated ground water to the
performance standards." The following were specified in the ROD as treatment technologies
which were determined to be effective in treating highly contaminated ground water and may be '
use.d to treat the contaminated ground water collected from the Site: gravity-phase separation for
nonaqueous phase liquids; lime soda softening for metals, radionuclides, hardness, and solids;
and biological treatment (powdered activated carbon treatment, PACT) to remove organic
compounds, biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia,
and nitrate. In addition, the ROD specifies that the treated water will be injected into the shallow
ground-water system downgradient of the Site.
Respondents' Proposed Remedial Design (Alternative 1)
Because the ROD does not specifically identify a treatment technology, an evaluation of potential
treatment options was prepared by the City and County of Denver (Denver), Waste Management
of Colorado, Inc. (WMC), and Chemical Waste Management, Inc. (CWM), Respondents to the
Administrative Order for Remedial Design/Remedial Action (RD/RA Order). The Respondents'
report is entitled Draft Evaluation of the POTW Treatment Option (dated April 23, 1996). In this
evaluation, the Respondents evaluated four possible remedial designs:
Alternative 1 - Onsite treatment for removal of organics using air stripping and carbon
adsorption, and offsite treatment for removal of inorganics and remaining organic
contaminants using a POTW;
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Alternative 2A- Onsite organics removal by air stripping and carbon adsorption, and
inorganics removal by reverse osmosis; onsite discharge of treated water by injection;
offsite disposal of reverse osmosis brines;
Alternative 2B- Organics removal by air stripping and carbon adsorption, and
inorganics removal by reverse osmosis/evaporation; onsite discharge of treated water
by injection; offsite disposal of evaporator sludges; and
Alternative 2C- Organics removal by air stripping and carbon adsorption, and
inorganics removal by evaporation; offsite disposal of evaporator sludges.
The Respondents' proposed remedial design (Alternative 1) will include onsite pretreatment
of the Site ground water to meet publicly owned treatment works (POTW) influent standards,
discharge to the City of Aurora's connection line and lift station, and conveyance to the
Metro Wastewater Reclamation District (Metro) facility for final treatment and disposal.
This alternative differs from the ROD in that the ground water would be pretreated for
organics onsite and discharged to Metro's POTW for inorganics and additional organics
treatment. The proposed remedial design was prepared in response to changes in Site and
administrative conditions. The following items have occurred since issuance of the ROD:
A new sanitary sewer interceptor and connection line was constructed one-half mile
from the Site;
The City of Aurora has agreed to allow connection of a discharge line from the Site
to the sewer line;
The City of Aurora has a cooperative agreement with Metro to allow water to be
conveyed through the discharge line to Metro's POTW; and
Metro has agreed to accept Site waters for treatment.
In light of the above-mentioned conditions, analysis of the POTW alternative, originally
discussed in the Stage 3 Feasibility Study for Operable Units 1 and 6, was performed by the
Respondents.
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3
CLLEAN's Proposed Remedial Design (Modified Alternative 2B)
After reviewing the Respondents' proposed remedial design (Alternative 1), Citizens for
Lowry Landfill Environmental Action Now (CLLEAN) proposed another approach to
remediation. To address their concern that the Respondents' remedial design would reduce
the water resources within the Arapahoe Formation, CLLEAN proposed that a modified
version of Alternative 2B be selected as the ground-water treatment component of the
sitewide remedy.
As indicated in the Respondents' evaluation, Alternative 2B includes onsite treatment for
organics and inorganics, onsite discharge of treated water by injection into the aquifer, and
offsite disposal of evaporator sludge. CLLEAN proposed the following modifications to
Alternative 2B:
Utilize a two-stage reverse osmosis (RO) system for near complete recovery of the
treated water, which would eliminate the need for injection water augmentation and
would gain community acceptance.
Recycle the steam, which would be generated by the evaporator, through a heat
exchanger to pre-heat the incoming water stream. This will eliminate the steam
plume that would otherwise be emitted from the evaporator and would gain
community acceptance.
Utilize the recovered water to augment the wetlands program. This would also gain
community acceptance.
CLLEAN also claimed that the additional truck traffic generated under the Modified
Alternative 2B would be inconsequential since there is already a high level of existing truck
traffic resulting from landfilling operations at the nearby Denver Arapahoe Disposal Site
(DADS). CLLEAN judged the reduction of toxicity, mobility, and volume to be better for
Modified Alternative 2B than Alternative 1 because volume would be reduced via the
evaporation system and the sludge would be placed in a secure landfill rather than
landfarmed. CLLEAN also asserted that the costs are equal, within the range of engineering
uncertainty. Likewise, CLLEAN estimated that the short-term effectiveness and compliance
with applicable or relevant and appropriate requirements (ARARs) are equal. CLLEAN
judged Modified Alternative 2B to be more effective in the long-term. CLLEAN based this
conclusion on the assumption that the concentration of contaminants in the Site discharge
might increase to levels above POTW influent standards, thereby creating a problem.
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Comparison of Alternatives
This section presents a comparison of the two alternatives using EPA's nine evaluation
criteria: overall protection of human health and the environment; compliance with ARARs;
long-term effectiveness and permanence; reduction of toxicity. mobility, or volume (TMV)
through treatment; short-term effectiveness; implementability: cost; State acceptance; and
community acceptance. A comparative analysis provides the basis for determining which
alternative presents the best balance between the nine criteria.
Overall Protection of Human Health and the Environment
This criterion addresses whether an alternative provides adequate protection and describes
how risks posed through each pathway are eliminated, reduced, or controlled. Overall
protection of human health and the environment draws on the assessments of other
evaluation criteria, especially long-term effectiveness and permanence, short-term
effectiveness, and compliance with ARARs. Both of the alternatives would be protective of
human health and the environment and would provide equal levels of organics removal.
However, Alternative 1 would be more effective at treating inorganic contaminants within
the waste stream.
Both alternatives would be protective of human health and the environment because they
would both treat to meet ARARs and health-based standards, thereby minimizing potential
exposure to site contaminants. In addition, monitoring would be used to ensure effectiveness
of either of the alternatives)
Compliance with ARARs
This criterion addresses whether a remedy will meet all Federal and State environmental
laws. Both of the alternatives would be constructed, operated, and maintained in accordance
with the ARARs specified in1 the ROD. These include, but are not limited to, Colorado
Water Quality Control Act, Safe Drinking Water Act, Colorado Discharge Permit System,
Federal Water Pollution Control Act, National Pollutant Discharge Elimination System,
Colorado Air Quality Act, Clean Air Act, and the Colorado Hazardous Waste Act. Modified
Alternative 2B will produce a concentrated hazardous waste sludge that would require
disposal in an approved Resource Conservation and Recovery Act (RCRA) Subtitle C
hazardous waste landfill. Sludge produced at Metro's POTW will meet the definition of
"exceptional quality sludge" and will be suitable for soil amendment purposes.
Long-Term Effectiveness and Permanence
This criterion refers to the ability of an alternative to provide reliable protection of human
health and the environment over time. It assesses the risk remaining after treatment
objectives are achieved, including magnitude of residual risk and adequacy and reliability of
controls. The magnitude of residual risk is equal for both alternatives since both alternatives
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treat equal amounts of water. Specifically, this criterion assesses the risk resulting from
residuals that remain after treatment. Based on Metro's established record as the wastewater
treatment and disposal entity for the Denver metropolitan area, it is assured that the POTW
will provide continued wastewater treatment throughout the life of the remedy. POTWs are
widely used and have shown to be a reliable and effective means of treatment. Potential
fluctuations of chemical concentrations in site water would be addressed equally for either
alternative by identifying the changes during monitoring and making adjustments to either
the pretreatment or onsite treatment systems.
Reduction of Toxicity, Mobility, or Volume through Treatment
This criterion refers to the preference for an alternative that reduces health hazards of
contaminants, the movement of contaminants, or the quantity of contaminants through
treatment. Both of the alternatives achieve reduction of TMV through treatment as evaluated
by the following criteria:
treatment process used;
degree and quantity of TMV reduction;
irreversibility of TMV reduction; and
type and quantity of treatment residual.
Both alternatives use air stripping and carbon for organics removal. Organics would be
irreversibly destroyed because the organics will be thermally destroyed (air stripper residuals
in LFG flare and carbon through regeneration). For Alternative 1, organic contaminants
passing through the onsite treatment system would be removed at the POTW. For Modified
Alternative 2B, trace organics passing through the onsite treatment system would not be
treated; these trace organics would be transferred to the air through the evaporation system.
Neither alternative irreversibly treats inorganics. Under Alternative 1, trace amounts of
metals will be collected in the1 nonhazardous sewage sludge produced by the POTW.
Alternative 2B remove metals through RO and evaporation, resulting in a hazardous waste
sludge that will require disposal at a RCRA Subtitle C facility. The quantity of sludge by
either alternative will be about the same.
Both alternatives satisfy the statutory preference for treatment to reduce toxicity, mobility,
or volume as a principle element.
Short-Term Effectiveness
This criterion addresses the period of time needed to complete an alternative, and any
adverse effects to human health and the environment that may be caused during the
construction and implementation of the alternative. Short-term effectiveness refers to the
impacts of the remedial action during construction and implementation, up to the point when
treatment objectives are achieved. It includes evaluation of the:
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protection of workers during remedial action;
protection of the community during remedial action;
environmental impacts of remedial action; and
time until protection is achieved.
Potential for worker exposure would be minimized through adherence to a health and safety
plan. Remedial construction under both alternatives is expected to be low short-term risk to
the community. There will be offsite pipeline construction activities associated with
Alternative 1. As a result, there will be some short-term traffic impacts to the area directly
west of the Site.
Under Alternative 1, the ground water will be pre-treated onsite to remove organic
contaminants to levels protective of Metro's POTW maintenance workers and compatible
with Metro's treatment processes. Risks would be low because the POTW influent standards
are protective of sewer maintenance personnel, as well as receptors located downstream of
the POTW discharge.
Handling and offsite transportation of hazardous waste sludge, produced under Modified
Alternative 2B, could present an increased risk to onsite workers and the surrounding
community. Under Alternative 1, the pre-treated water that would be piped offsite for further
treatment at the Metro facility would contain organic contaminants at measurable levels.
However, the presence of Lowry water in the sewer system would not result in an increased
risk because the water would not be hazardous.
Alternative 1 provides a positive environmental impact because the sewage sludge produced
at Metro's POTW may be used as a soil amendment. Modified Alternative 2B provides a
negative environmental impact because this alternative would produce a hazardous waste that
would have to be disposed at a RCRA Subtitle C landfill.
Alternative 1 will have a construction time frame of three to four months, while Modified
Alternative 2B will have a construction schedule of about 14 months. In addition, the time
frame for design will be significantly less for Alternative I than Modified Alternative 2B.
Alternative 1 would involve augmenting the offsite alluvial aquifer system with ground water
withdrawn, at a rate of about 10 gallons per minute (gpm), from an onsite well completed in
the Arapahoe Formation. Computer modeling simulations suggest that drawdown will be
about 0.02 feet per year in the onsite well. The Respondents have verified that they are
legally entitled to withdraw ground water from the Arapahoe Formation. Although the
amount of water loss associated with Modified Alternative 2B would be less than that for
Alternative 1, a water augmentation program would be necessary nonetheless. It is estimated
that Alternative 2B would require augmentation of about 2 gpm, which would result in a
drawdown of about 0.004 ft/year.
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Implementability
This criterion refers to the technical and administrative feasibility of an alternative, and
includes the availability of materials and services needed to carry out an alternative. It also
includes coordination efforts between Federal, State, and local government.
Implementability consists of the following criteria: technical feasibility; administrative
feasibility; and availability of services and materials.
Both of the alternatives are implementable from a technological point of view. Startup and
operation of the onsite inorganics treatment system for Modified Alternative 2B would
involve a significant amount of effort and is a complex engineering process in comparison
to the treatment option proposed in Alternative 1. A key feature of Alternative 1 involves
piping the ground water to Metro's POTW. In doing so, there will be no need to upgrade the
onsite treatment system, thereby simplifying future operation and maintenance efforts.
There are administrative and permitting issues for both of the alternatives. In order to pipe
the ground water to Metro's POTW, a discharge permit would be required. In addition, the
City of Aurora has already granted approval for the sewer line to be connected to the Site,
for the purpose of transferring the ground water to Metro's connection line. A modification
to the existing CDPHE Air Pollutant Emission Notice (APEN) for the air stripper will be
required for either alternative. Modified Alternative 2B will require an additional APEN for
the evaporator emissions.
Availability of services and materials would be more notable for Alternative 1 because the
POTW is already in operation and sewer line materials are readily available. For Modified
Alternative 2B, procurement of a two-stage RO system with an evaporator would be more
specialized.
Cost
i
This criterion evaluates the estimated capital, operation, and maintenance (O&M) costs of
each alternative in comparison to other equally protective alternatives. Net present worth
costs were estimated by adding the capital costs to the net present value of the annual
operations and maintenance (O&M) costs for thirty years, using an interest rate of 5 percent.
The net present worth cost for Alternative 1 is estimated to be $6,354,000. This includes
capital costs for a lift station, piping, excavation and construction, and the sewer connection
fee ($423,110), design and construction management costs ($100,000), O&M costs for acid
and caustic, equipment repairs, liquid and vapor carbon changeout, POTW treatment fee,
labor, and electricity ($366,550 per year), and water augmentation costs ($196,569).
The net present worth cost for Modified Alternative 2B is estimated to be $9,300,000. This
cost was calculated by the Respondents in a letter to EPA dated June 17, 1996. The net
present worth cost includes capital costs for a reverse osmosis (RO) system, an iron removal
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8
system, and an evaporation system ($780,000), design and construction management costs
($100,000), O&M costs for acid and caustic, RO and iron filter replacement, equipment
repairs, liquid and vapor carbon changeout, sludge and filter disposal, labor, and electricity
($410,376 per year), and water augmentation costs ($75,392). In addition, it includes costs
for pretreatment for the RO and evaporator systems (capital and chemical costs). The
Respondents' estimate that 100 percent recovery of water for injection will not be achieved
and that approximately 1 to 2 gpm would be required for augmentation. The costs for this
augmentation water is included in the net present worth estimate.
State Acceptance
This criterion indicates whether the State agrees with, opposes, or has no comment on a
given alternative. CDPHE consults with EPA on decisions made at the Site and has shown
a preliminary preference for Alternative 1.
Community Acceptance
This criterion includes determining which alternatives are supported by interested persons
within the community and which ones are opposed. The community does not accept
Alternative 1. Although the Respondents legally own the water rights to an onsite well that
could be used for augmentation purposes, the community is concerned about depletion of
water resources in the area. In addition, the Respondents have conducted ground-water
modeling of the effects of pumping the Arapahoe Formation well at 10 gpm and have
concluded that a drawdown of approximately 0.02 feet may be expected below the Site after
one year of continuous pumping. Ground-water drawdown would be less in surrounding
areas.
The community is also concerned that drawdown of ground water within the Arapahoe
Formation may cause increased vertical migration of Site contaminants. However, the
presence of aquitards between'the Arapahoe and Denver Formations, and the Arapahoe and
Laramie/Fox Hills Formations, suggests that it is unlikely that the pumping will affect either
of these aquifers.
Transportation of hazardous waste through the surrounding neighborhoods would be
considered a negative community acceptance factor for Modified Alternative 2B. The
amount of hazardous waste to be generated under this alternative is estimated to be one
truckload per month. Despite the reduced rate of waste generation and small increase in
truck traffic, the threat of an accident involving the transportation of hazardous waste would
also be considered a public concern.
Community acceptance for Modified Alternative 2B is considered high because it was
developed by a citizens' group, CLLEAN. Modified Alternative 2B would involve less
aquifer depletion than Alternative 1.
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Preferred Alternative
The attached table presents a scoring system for comparing the two alternatives. Alternative
1 received the higher score and is considered to be the alternative that achieves the best
balance between the nine criteria. While Alternative 1 is not endorsed by the community,
it achieves better long-term effectiveness, provides for a more pronounced reduction in
toxicity, mobility and volume through treatment, is more irnplementable, is more cost
effective, and would not produce a hazardous waste sludge.
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10
EPA Assessment Criterion
1 . Overall Protection of Human Hculth & the
Environment
2. Compliance with ARARs
3. Long-Term Effectiveness and Permanence
4. Reduction of TMV Through Treatment
5. Short-Term Effectiveness -
6. Implemeniability
7. Cost
8. State Acceptance
9. Community Acceptance
Total Score
Alternative 1
5
5
3
4
3
5
4
-
-
29
Modified Alternative 2B
5
5
2
3
3
3
2
'
-
23
Note: 5 = completely achieves the objectives of the criterion; 1 = minimally achieves the objectives of the criterion
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Technical Evaluation of Proposed Former Tire Pile Area Treatment
and Disposal Alternatives for the Lowry Landfill Superfund Site
DEN/H/DA/WORDPWIN/IOI.WPD
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Technical Evaluation of Proposed Former
Tire Pile Area Treatment and Disposal
Alternatives
for the Lowry Landfill Superfund Site
Introduction
This document supplements the proposed Explanation of Significant Differences (ESD), for the
Lowry Landfill Superfund Site (Site) in Arapahoe County, Colorado. New information has been
submitted to the U.S. Environmental Protection Agency (EPA) and the Colorado Department of
Public Health and Environment (CDPHE) pertaining to the treatment and disposal component of the
remedy for contaminated materials in the former tire pile area (FTPA). This document summarizes
the proposed remedial design alternatives for the FTPA treatment and disposal, analyzes the remedial
design alternatives against the nine EPA criteria, and selects a preferred FTPA treatment remedial
design.
FTPA Treatment and Disposal Remedy in ROD
The March 10, 1994 Record of Decision (ROD) for the Site specifies that "...contaminated materials
in the former tire pile area shall be excavated and characterized for offsite treatment and disposal."
Furthermore, the ROD states that "...it is anticipated that the solids and soils shall be treated using
stabilization before disposal, but actual treatment methods shall be determined by EPA, in
consultation with CDH, during RD." For the purposes of this technical memorandum, the alternative
identified in the ROD will be referred to as Alternative 1.
Respondents9 Proposed Remedial Design
Because the ROD does not specifically identify a treatment technology, treatability studies and an
evaluation of potential treatment options were performed by the City and County of Denver
(Denver), Waste Management of Colorado, Inc. (WMC), and Chemical Waste Management, Inc.
(CWM), Respondents to the Administrative Order for Remedial Design/Remedial Action (RD/RA
Order). The Respondents' report is entitled Treatability Test Summary Report, Former Tire Pile
Area Waste Pits (dated February 19, 1997). In this evaluation, the Respondents evaluated two
possible remedial designs:
physical drying/controlled aeration
enhanced bioremediation
Results from the treatability tests indicated that enhanced bioremediation would not meet the
remedial objectives. Consequently, physical drying/controlled aeration will be the only alternative
of the two that is carried forward for evaluation in this technical memorandum. For the purposes of
this technical memorandum, the Respondents' remedial design will be referred to as Alternative 2
and includes the following elements:
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excavation, handling, and staging of FTPA waste pit materials
treatment of FTPA waste pit materials
disposal of treated materials in an onsite cell or other designated area onsite
Comparison of Alternatives
This section presents a comparison of the two alternatives using EPA's nine evaluation criteria:
overall protection of human health and the environment
compliance with applicable or relevant and appropriate requirements (ARARs)
long-term effectiveness and permanence
reduction of toxicity, mobility, or volume (TMV) through treatment
short-term effectiveness
implementability
cost
State acceptance
community acceptance
A comparative analysis provides the basis for determining which alternative presents the best balance
between the nine criteria. The two alternative evaluated are:
Alternative 1, offsite treatment and disposal
Alternative 2, onsite treatment and disposal
Overall Protection of Human Health and the Environment
This criterion addresses whether an alternative provides adequate protection and describes how risks
posed through each pathway are eliminated, reduced, or controlled. Overall protection of human
health and the environment draws on the assessments of other evaluation criteria, especially long-
term effectiveness and permanence, 'short-term effectiveness, and compliance with ARARs. Both
of the alternatives would be protective of human health and the environment and would provide
equal levels of treatment (removal of hazardous characteristics). Both alternatives would treat to
meet ARARs, thereby minimizing potential exposure to site contaminants.
Compliance with ARARs
This criterion addresses whether a remedy will meet all Federal and State environmental laws. Both
of the alternatives would be constructed, operated, and maintained in accordance with the ARARs
specified in the ROD. These include, but are not limited to, the Colorado Hazardous Waste Act and
the Resource Conservation and Recovery Act (Subtitles C and D). Under both alternatives, the
materials from the FTPA would be treated to remove hazardous characteristics (such as ignitability
and toxicity) and will comply with ARARs.
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Long-Term Effectiveness and Permanence
This criterion refers to the ability of an alternative to provide reliable protection of human health and
the environment over time. It assesses the risk remaining after treatment objectives are achieved,
including magnitude of residual risk and adequacy and reliability of controls. The magnitude of
residual risk is equal for both alternatives since both alternatives treat equal amounts of material.
Under Alternative 2, the material will be remain onsite for disposal. For Alternative 1, the material
will be disposed offsite.
Reduction of Toxicity, Mobility, or Volume through Treatment
This criterion refers to the preference for an alternative that reduces health hazards of contaminants,
the movement of contaminants, or the quantity of contaminants through treatment. Both of the
alternatives achieve reduction of toxicity, mobility, and volume (TMV) through treatment, as
evaluated by the following criteria:
treatment process used;
degree and quantity of TMV reduction;
irreversibility of TMV reduction; and
type and quantity of treatment residual.
Both alternatives will remove the hazardous characteristics of the material. Alternative 1 assumes
stabilization will be used. Although stabilization would reduce the toxicity and mobility of
contaminants, overall volume would increase because stabilizing materials such as cement would
be added to the waste pit materials. Alternative 2 uses physical drying/controlled aeration and air
emissions from this process will be treated using carbon adsorption or thermal treatment. Alternative
2 will achieve reductions in toxicity, mobility, and volume.
Both alternatives satisfy the statutory preference for treatment to reduce toxicity, mobility, or volume
as a principle element. ,
Short-Term Effectiveness
This criterion addresses the period of time needed to complete an alternative, and any adverse effects
to human health and the environment that may be caused during the construction and implementation
of the alternative. Short-term effectiveness refers to the impacts of the remedial action during
construction and implementation, up to the point when treatment objectives are achieved. It includes
evaluation of the:
protection of workers during remedial action;
protection of the community during remedial action;
environmental impacts of remedial action; and
time until protection is achieved.
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Potential for worker exposure would be minimized through adherence to a health and safety plan.
Both alternatives include excavation, treatment, and disposal and, therefore, represent similar
exposure risks to workers.
Remedial construction under both alternatives is expected to be low short-term risk to the
community. Alternative 2 will take longer because excavation and treatment would both occur
onsite, whereas Alternative 1 will have a short onsite duration because the treatment would occur
offsite. Offsite transportation of hazardous waste under Alternative 1 could present an increased risk
to onsite workers and the surrounding community.
Implementability
This criterion refers to the technical and administrative feasibility of an alternative, and includes the
availability of materials and services needed to carry out an alternative. It also includes coordination
efforts between federal, state, and local government. Implementability consists of the following
criteria: technical feasibility; administrative feasibility; and availability of services and materials.
Both of. the alternatives are implementable from a technological point of view. They both use
currently available technologies and standard equipment.
There are administrative requirements for both of the alternatives. In order to haul the hazardous
waste pit material offsite in Alternative 1, manifests must be properly filled out and signed. In order
to treat the material onsite in Alternative 2, a CDPHE Air Pollutant Emission Notice (APEN) will
be required. These administrative requirements are routine and should not delay or hinder the
project.
Cost
This criterion evaluates the estimated capital, operation, and maintenance (O&M) costs of each
alternative in comparison to other equally protective alternatives. Both alternatives are moderately
priced. Alternative 1 will be more expensive due to the high transportation costs of hauling the
waste pit material to a licensed hazardous waste disposal facility.
State Acceptance
This criterion indicates whether the State agrees with, opposes, or has no comment on a given
alternative. CDPHE consults with EPA on decisions made at the Site and will provide an indication
of its preference during the public comment period.
Community Acceptance
This criterion includes determining which alternatives are supported by interested persons within the
community and which ones are opposed. Community acceptance will be evaluated after the public
comment period on the proposed ESD.
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Preferred Alternative
The attached table presents a scoring system for comparing the two alternatives. The proposed
alternative received the higher score and is considered to be the alternative that achieves the best
balance between the nine criteria. Both alternatives would achieve long-term effectiveness; however
onsite treatment (Alternative 2) provides for a more pronounced reduction in toxicity, mobility-and
volume through treatment, is more cost effective, and would not require the offsite transportation
of hazardous waste.
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EPA Assessment Criterion
1. Overall Protection of Human Health & the Environment
2. Compliance with ARARs
3. Long-Term Effectiveness and Permanence
4. Reduction of TMV Through Treatment
5. Short-Tcrm Effectiveness
6. Implemenlahilily
7. Cost
8. State Acceptance
9. Community Acceptance
Total Score
Alternative 1
5
5
5
2
3
4
3
3
3
33
Alternative 2
5
5
5
4
3
4
5
4
4
39
Note: 5 = completely achieves the objectives of (he criterion; I = minimally achieves the objectives of the criterion
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Attachment F
Second Explanation of Significant Differences
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION VIII
9" 18th STREET - SUITE 500
DENVER, COLORADO 80202-2466
LOWRY LANDFILL SUPERFUND SITE
SECOND EXPLANATION OF SIGNIFICANT DIFFERENCES
OCTOBER 1997
Printed on Recycled Paper
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LOWRY LANDFILL SUPERFUND SITE
EXPLANATION OF SIGNIFICANT DIFFERENCES
October 1997
INTRODUCTION
The purpose of this document is to explain the significant differences between the
remedy selected in the Record of Decision (ROD) for the Lowry Landfill Superfund Site
in Arapahoe County, Colorado (Site), issued by the U.S. Environmental Protection
Agency (EPA) on March 10, 1994, and the remedy described herein. The changes
to the ROD have been made as a result of new information that EPA received
subsequent to the issuance of the ROD. These changes do not fundamentally alter
the sitewide remedy presented in the ROD. The sitewide remedy for the Site remains
protective of human health and the environment.
EPA is the lead agency for overseeing the cleanup of the Site; the Colorado
Department of Public Health and the Environment (CDPHE) is the support agency.
This Explanation of Significant Differences (ESD) provides a brief history of the Site,
describes the remedy selected in the ROD, and explains the ways in which the
remedy described herein differs from the remedy selected in the ROD. It also
summarizes the support agency's comments on the changes to the remedy and
discusses compliance with all legal requirements.
This ESD is prepared in fulfillment of EPA's public participation responsibilities under
Section 117(c) of the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980, 42 U.S.C. Section 9601, el saq. (CERCLA or Superfund), as
amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA),
and Section 300.435(c)(2)(i) of the National Contingency Plan (NCP), 40 C.F.R. Part
300. These laws and regulations require EPA to publish an ESD when the remedy to
be implemented differs significantly from the remedy described in the ROD.
PUBLIC PARTICIPATION
The administrative record, which contains this ESD and the documentation supporting
it, is available for public review at the following location:
EPA Superfund Records Center
999 18th Street, 5th floor North Terrace
Denver, Colorado 80202
(303) 312-6473
Hours: Monday-Friday - 8:00 a.m. to 4:30 p.m.
This ESD is also available at the following Lowry Site information repository:
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Aurora Public Library
14949 East Alameda Drive
Aurora, Colorado 80012
(303) 340-2290
Hours: Monday-Thursday - 10:00 a.m. to 10:00 p.m.
Friday and Saturday - 10:00 a.m. to 6:00 p.m.
Sunday - 12:30 p.m. to 6:00 p.m.
A notice of availability and brief description of the ESD was published in the Denver
Post and Rocky Mountain News on March 21, 1997, as required by CERCLA Section
EPA accepted public comment on these proposed modifications to the sitewide
remedy for a period of ninety (90) days. The comment period was from March 24,
1 997 to June 30, 1 997. Written comments were submitted to:
Marc E. Herman
Remedial Project Manager
U.S. Environmental Protection Agency
Mail Code 8EPR-SR
999 18th Street, Suite 500
Denver, Colorado 80202
SUMMARY OF SITE HISTORY, CONTAMINATION PROBLEMS,
AND SELECTED REMEDY
Summary of Site History and Contamination Problems
The Site is located northeast of the intersection of Quincy Avenue and Gun Club
Road, approximately 1 5 miles southeast of downtown Denver and two miles east of
the City of Aurora, Colorado (Figure 1). In 1930, the City and County of Denver
(Denver) purchased land including the Site to attract an Army Air Corps Technical
School to Denver. In 1 937, the Denver City Council conveyed title to the land to the
Federal government. From about 1940 to 1962, the U.S. Air Force used the Site as
a bombing range. In 1 964, the United States conveyed all or portions of the five
sections of the bombing range back to Denver by Quitclaim Deed.
From 1 966 until 1 980, Denver operated a municipal landfill at Section 6 on the Site,
accepting liquid and solid municipal and industrial wastes, including sewage sludge.
(Section 6 is the principal area of the Superfund Site. Section 31 , a portion of which
is included in the Superfund site, is currently used for municipal landfilling.) These
materials included hazardous substances, such as volatile organic compounds and
heavy metals, listed pursuant to 40 C.F.R. Section 302.4. Organic compounds are
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compounds that contain the e ement carbon in their molecular structure. Examples
of materials composed of organic compounds include petroleum products, solvents,
and pesticides. Inorganics are elements and compounds that do not contain carbon
in their molecular structure. Examples of inorganics are metals (such arsenic and
selenium), chlorides, and sulfates.
From 1966 until 1980, approximately 130 million gallons of waste were disposed of
at the Site, primarily by a disposal practice known as "co-disposal." Approximately
75 unlined waste pits or trenches were excavated to accommodate a mixture of
municipal and industrial wastes. In the southern half of the Lowry Site, the pits were
filled about three-quarters full with liquid wastes and topped with 25 to 60 feet of
municipal refuse. The waste pits ranged from approximately 15 to 30 feet in depth,
approximately 100 to 1,100 feet in length, and approximately 50 to 150 feet in
width. Over time, the liquids seeped out of the pits and mixed with the surrounding
refuse and ground water. In the north-central portion of the Lowry Site, excavated
pits were filled with liquid wastes and municipal refuse, then covered with two to
five feet of native soil and discarded tires. Over time, these liquid wastes seeped out
to ground water and to surface water in Unnamed Creek. Approximately 8 million
tires were stockpiled at the Site in the 1970s.
From 1969 until 1986, municipal sewage sludge was applied to approximately 160
acres along the northern and eastern boundaries of the Lowry Site. The sludge was
applied to the surface of the land and then incorporated into the native soils. After
1980, leachate collected in on-site surface impoundments was injected in the same
160-acre area. Both the municipal sewage sludge and the leachate contained
hazardous substances listed pursuant to 40 C.F.R. Section 302.4.
Preliminary investigations at the Site began in the mid-1980s. Various parties,
including EPA, CDPHE, and Denver, performed studies before 1984, when the Site
was placed on the Superfund National Priorities List. Contaminants were found in
surface water and sediments, ground water, soils, and landfill solids. From 1984 to
1993, a series of remedial investigation/ feasibility studies (RI/FSs) were performed
to study the nature and extent of the contamination and to investigate the potential
threats that the Site posed to human health and the environment.
Contaminated surface water and shallow ground water at the Site are currently being
addressed through two interim remedial measures: a ground-water barrier wall/
treatment facility and the Surface Water Removal Action (SWRA). The ground-water
barrier wall and SWRA are key components of the sitewide remedy selected in the
ROD.
EPA conceptually divided the Site into six Operable Units (OUs) for response and
grouped them according to the media that they address: OUs 1 and 6 address
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shallow ground water, subsurface liquids, and deep ground water; OUs 2 and 3
address landfill solids and gas; and OUs 4 and 5 address soils, surface water, and
sediments. Each medium contains hazardous substances listed pursuant to 40 C.F.R.
Section 302.4. The primary threats at the Site are posed by: landfill gas; waste-pit
liquids; contaminated ground water; and buried drums, drum contents, and
contaminated soils within the former tire pile area.
Summary of Selected Sitewide Remedy
Under the selected sitewide remedy, contaminated ground water shall be addressed
through containment, collection, and treatment, utilizing the existing treatment facility
or an upgraded facility. Landfill gas shall be addressed through containment,
collection, and treatment using enclosed flare technology. Contaminated seepage and
surface water are addressed through a drainage and underground collection system
in the Unnamed Creek area as part of the SWRA. The response action identified for
the former tire pile area shall address principal threats (drums, drum contents, and
contaminated soils) through treatment and offsite disposal to reduce the toxicity,
mobility, and volume of contaminants. Landfill mass solids and soils are low-level
threats at the Site that shall be addressed through containment.
DESCRIPTION OF SIGNIFICANT DIFFERENCES AND
THE BASIS FOR THOSE DIFFERENCES
Summary of Information Giving Rise to the Significant Differences
The changes memorialized in this ESD are based on remedial design documents that
have been submitted by Denver, Waste Management of Colorado, Inc., and Chemical
Waste Management, Inc., Respondents to the Administrative Order for Remedial
Design/Remedial Action, EPA Docket No. CERCLA VIM-95-05 (RD/RA Order). EPA has
considered the proposed changes and has determined that the information supports
the need to modify certain aspects of the remedy described in the ROD. These
changes do not fundamentally alter either the overall approach of the sitewide remedy
or any individual component of the sitewide remedy.
Description of Significant Differences
The significant differences are as follows:
1. The ROD (Subsection 11.3.1) states that contaminated materials in the former
tire pile area shall be excavated and characterized for offsite treatment and
disposal.
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As part of remedial design, the Respondents performed treatability tests on the
excavated waste to evaluate the possibility of treating and disposing the
contaminated materials onsite. The two treatability tests were: physical
drying/controlled aeration; and enhanced bioremediation. For the physical
drying/controlled aeration test, covered stockpiles of soils/sludges were
allowed to dry in a controlled manner. Air emissions associated with this test
were monitored to provide a basis for designing engineering controls for
emissions from the full-scale treatment system. The enhanced bioremediation
test involved aerobic biodegradation (a process in which bacteria degrade or
destroy organic compounds). For the enhanced bioremediation test, stockpiles
of soils/sludges were treated with bacteria. Bacterial growth was controlled
by regulating the amount of oxygen and nutrients, and the temperature, within
the stockpiles.
After evaluating the results of the treatability tests, EPA selected physical
drying/controlled aeration as the method of treatment. In order to dispose of
these wastes onsite, the contaminated materials shall be treated to meet RCRA
Subtitle C and D requirements of the Solid Waste Disposal Act and the
Colorado Hazardous Waste Act.
2. In the ROD (Subsection 11.2.2), it is stated that:
(a) the ground-water remedy shall treat approximately 6.4 million gallons of
contaminated ground water annually, collected from the new and
existing collection systems and barrier walls; and
(b) a new onsite treatment plant shall be designed and constructed unless
it can be demonstrated through pilot-testing that the existing plant can
be upgraded to effectively treat the more highly contaminated ground
water from the toe of the landfill.
As discussed in the ROD, contaminated ground water shall be collected at the
northern barrier wall and at the north toe collection system and shall be treated
onsite to address organic contaminants. The change to the above-mentioned
components of the ROD involves the piping of pre-treated ground water offsite
for treatment of inorganic contaminants and remaining organics at the Metro
Wastewater Reclamation District (Metro) facility, a Publicly Owned Treatment
Works (POTW), and the City of Aurora's (Aurora's) Sand Creek Wastewater
Reclamation Facility, also a POTW.
The POTWs shall issue an enforceable discharge permit to the Respondents
and require that the water discharged to the POTWs meets contaminant-
specific limits. Metro's and Aurora's authority to issue discharge permits has
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been previously approved by both EPA and CDPHE, pursuant to section 402
of the Federal Water Pollution Control Act, also known as the Clean Water Act.
By receiving approval of their Pretreatment Programs, Metro and Aurora are
authorized to enforce the requirements of sections 307{b) and (c), and
402(b)(8) of the Clean Water Act. The contaminant-specific limits identified
in the discharge permit shall be set to ensure that the POTWs shall:
Comply with its Colorado Discharge Permit System/National Pollutant
Discharge Elimination System discharge permit;
Comply with State water quality standards;
Achieve risk-based effluent concentration limits developed by EPA for
pollutants not regulated by water quality standards;
Maintain "exceptional quality sludge" levels of pollutants, as defined by
Table 3 of 40 C.F.R. Section 503.13, in Metro's biosolids products
(Aurora's POTW pipes its biosolids to Metro, via the sewer system, for
treatment);
Prevent interference with the POTWs1 treatment processes;
Restrict releases of hazardous air pollutants from the POTWs' facilities;
and
Protect workers from adverse health and safety effects caused by the
presence of toxic and reactive gases in the sewer system.
SUPPORT AGENCY COMMENTS
t
CDPHE concurs with the ESD and the changes to the selected remedy.
AFFIRMATION OF STATUTORY DETERMINATIONS
Considering the new information that has been received and the changes that have
been made to the selected remedy, EPA and CDPHE believe that the remedy remains
protective of human health and the environment, complies with Federal and State
requirements that are applicable or relevant and appropriate to this remedial action,
and is cost-effective. In addition, the revised remedy utilizes permanent solutions and
alternative treatment technologies to the maximum extent practicable for this Site.
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OCT 24 1997
Max H. Dodson Date
Assistant Regional Administrator
Office of Ecosystems Protection and Remediation
U.S. Environmental Protection Agency, Region 8
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LIST OF ACRONYMS
ARARs Applicable or Relevant and Appropriate Requirements
CDPHE Colorado Department of Public Health and Environment (also known as
CDH)
CERCLA Comprehensive Environmental Response, Compensation, and Liability
Act of 1980
C.F.R. Code of Federal Regulations
EPA U.S. Environmental Protection Agency
ESD Explanation of Significant Differences
FS Feasibility Study
MSW Municipal Solid Waste
NCP National Oil and Hazardous Substances Pollution Contingency Plan
OU Operable Unit
POTW Publicly Owned Treatment Works
RA Remedial Action
RCRA Resource Conservation and Recovery Act of 1976
RD Remedial Design
Rl Remedial Investigation
ROD Record of Decision
SARA Superfund Amendments and Reauthorization Act of 1986
SWRA Surface Water Removal Action
List of Figures
Figure 1 Location Map
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LEGEND
floaoi
Topognpnic Conioura (interval 601
S«eoon Numo«r
The tocaaons trtown ir* oproamai*.
1
THE LOWRY SfTE
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Attachment G
Biosolids References
DEN/H/DAAVORDPWIN/IOl.WPD
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Chapter 7
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EPA Materials Available From:
Office of Water Resource Center (OWRC)
U.S. EPA
401 M Street SW (RC-4100)
Washington, DC 20460
Phone: (202) 260-7786
Center for Environmental Research Information (CERI)
26 West Martin Luther King Drive
Cincinnati, OH 45268
Phone: (513) 569-7562
Fax:(513)569-7585
i
National Technical Information Service (NTIS)
U.S. Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
Phone: (800) 553-6847
(703) 487-4650
Fax:(703)321-8547
Education Resource Information Center (ERIC)
c/o West Virginia University
P.O. Box 6064
Morgantown, WV 26506-6064
Phone:(614)292-6717
Fax: (614)292-0263
Part 503 Risk Assessment &EPA 125
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Chapter 7
Specialists To Contact for More Information
About Risk Assessment
Dr. Jim Ryan
EPA Office of Research & Development
(513)569-7653
Dr. John Walker
EPA Office of Wastewater Management
(202) 260-7283
About Risk Assessment and Derivation of the Rule
Mr. Robert Southworth
EPA Office of Science and Technology
(202)260-7157
126 fi-EPA Part 503 Risk Assessment
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