PB98-963145
EPA 541-R98-157
March 1999
EPA Superfund
Record of Decision Amendment:
Moss-American
(Kerr-McGee Oil Co.)
Milwaukee, WI
9/30/1998
-------
Declaration for an Amendment to the Record of Decision
Purpose
The purpose of this decision document is to present an amendment to the Record of Decision
(ROD) for the Moss-American Site, which is located in Milwaukee, Wisconsin. This decision
was reached in accordance with the Comprehensive Environmental Response, Compensation,
and Liability Act of 1980 (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA) and the National Contingency Plan (NCP).
Basis
The decision to amend the ROD is based upon the administrative record. The index attached to
the amended ROD identifies the items that comprise the administrative record upon which the
selection of the amended portion of the remedial action is based.
Description of the Amendment
The ROD amendment for the Moss-American site has three principal components:
1) changes in soil treatment technology, 2) potential changes in cleanup standards, and 3)
changes in cover design and requirements.
Soil Treatment Technology
First, the ROD is amended to replace the biodegradation treatment system with low temperature
thermal desorption. As described in the ROD originally developed for this site, areas of more
highly contaminated soils were to undergo treatment utilizing biodegradation in the form of a
bioslurry technique prior to consolidation and containment with less contaminated soil areas.
Cleanup standards
Second, the ROD amendment allows for the utilization of new cleanup standards for the portion
of the site referred to as the "former wood preserving facility" owned by the Union Pacific
Railroad and Milwaukee County, provided certain conditions are met. The ROD amendment
recognizes that it may be appropriate to adopt industrial or recreational exposure scenarios for
site users exposed to contaminants of concern in surface soils. Portions of the site owned by
Union Pacific Railroad, and upland site areas of the former wood preserving facility owned by
Milwaukee County could utilize an industrial usage risk exposure scenario if deed restrictions are
signed and recorded which limit the use of the property. If appropriate land use restriction are
obtained, then Union Pacific site property and upland areas of Milwaukee County site property
can use the industrial soil cleanup standards established in Wisconsin Administrative Code NR
720 for direct contact and for the protection of groundwater. For Milwaukee County property
which is part of the former wood preserving facility and which is located in the floodplain of the
Little Menomonee River, a recreational exposure scenario may be appropriate if deed restrictions
are signed and recorded which limit the use of the property to recreational uses. If this type of
-------
land use restriction is effectuated, then soil cleanup standards established under ch. NR 720, for
recreational land use can be utilized. Control measures attendant to appropriate soil erosion and
runoff protection shall also be employed so that contaminants associated with those soils do not
pose an undue threat to sediment quality in the nearby Little Menomonee River. U.S. EPA
expects that it would take no longer than 180 days after the date of issuance of this decision to
secure necessary deed restrictions. If the appropriate land use restrictions and maintenance
agreements can not be obtained for any given portion of the former wood preserving facility
within this 180- day timeframe, then soil cleanup standards established under Wisconsin
Administrative Code NR 720 for residential land use, or the soil cleanup standards set forth in ~
the 1990 ROD must be attained for that portion of the Site. Soils exceeding those standards shall
be excavated, and if necessary, treated, prior to consolidation in a new disposal unit established
pursuant to Hazardous Waste Corrective Action Management Unit (C AMU) requirements.
Cover
Finally, reconsideration is also given herein to the appropriate means of containing treated
residuals, from the more highly contaminated soils and sediments, as well as soils with low
levels of contamination. Given the nature of the primary contaminants of concern, a waiver was
considered and granted in the original ROD so as to allow usage of a relatively permeable soil
cover. The theory behind this decision was that the flushing action allowed by such a cover
would drive the remaining relatively low levels of contaminants out of the soil mass and into the
groundwater, such that groundwater cleanup goals could be attained in a relatively short time
span, on the order of five to ten years. However, predesign field work at the site indicated not
only that free product creosote was present near the soil/groundwater interface, but also that it
was present in relatively large extractable quantities. Creosote associated with groundwater is a
subset of those contaminants known as dense nonaqueous phase liquids (DNAPLs). The
presence of such materials complicates groundwater management.
Beginning in 1995, efforts began at the site to extract such DNAPLs, and arrange for their off-
site shipment. Some soil zones selected for thermal desorption treatment were chosen because of
their association with free-product creosote. Hence, DNAPL control efforts have been/will be
conducted. In 1997, an Explanation of Significant Differences (ESD) was issued to revise the
groundwater remedy to include containment components utilizing sheet walls and in-situ
treatment of groundwater. This will effectively minimize the spread of contaminants and
DNAPL materials in the soils and groundwater regardless of the amount of infiltration into the
contamination zone. Therefore, the need for flushing is minimized, and the groundwater
restoration should be relatively unaffected by the amount of infiltration allowed through a cover
system. The design of any cover system should be based on what is protective of human health
and the environment, given the nature of the material to be covered, and what meets applicable
and relevant and appropriate requirements (ARARs). As set forth in the section of this document
concerning soil cover and Corrective Action Management Unit (CAMU), depending on the level
of soil treatment provided, a clay cap topped with a suitable frost-protection soil layer or a simple
soil cover may be used to replace the soil cover originally selected. A new disposal unit will be
established pursuant to CAMU requirements under Wisconsin Chapter NR 636. CAMU allows
consolidation and placement of certain hazardous remediation wastes without triggering new
disposal events which would otherwise require application of land disposal requirements, and
-------
liner and leachate collection systems, provided that the activity is protective of human health and
the environment. Given the expected level of soil treatment efficiency, a CAMU can be utilized,
without the subsurface synthetic membrane and leachate collection system that would constitute
a hazardous waste containment cell.
Statutory Determinations
The selected remedy in this amendment is protective of human health and the environment,
complies with Federal and State requirements that are legally applicable or relevant and
appropriate to the remedial action, and is cost effective. The 1990 ROD justified a waiver
pursuant to Section 121(dX4)(B) for a Subtitle C cap and for the State double-liner/leachate
collection system requirement on the basts that an impermeable cap and liner would pose a
greater risk to health and the environment by prolonging groundwater treatment and time needed
to achieve groundwater goals. Given the greater presence of DNAPLs found since that time,
waiver of a relatively impermeable cap is no longer justified. However, given the source control
measures to be taken regarding soils, and the establishment of a CAMU, a double-liner /leachate
collection system is not required. The remedy satisfies the statutory preference for treatment as a
principal element. Because this remedy will result in hazardous substances remaining on site
above health-based levels, a review will be conducted within five years after the commencement
of remedial action to ensure that the remedy continues to provide adequate protection of human
health and the environment. The State of Wisconsin has indicated it will provide conditional
concurrence with this Record of Decision Amendment. The State of Wisconsin's letter
indicating this position will be included in the Administrative Record for the site.
-. C.
DAT£ William E. Muno, Defector
Superfund Division
-------
Table of Contents
Contept ________^_ Page Number
Introduction 1
Public Comment Period 3
Site History 3
Changes to the Remedy 5
Thermal Desorption and Bioslurry Consideration 5
Areas to Undergo Thermal Desorption , 8
Allowance for Adoption of Industrial or Recreational Exposure 10
Scenarios for Soils Risk Consideration
Industrial Usage , 10
Industrial Remediation Levels 12
Background Considerations 12
Recreational 13
Permeable Soil Cover - Waiver Withdrawal and 14
Establishment of a CAMU
Treatability Variance Adjustment 17
Evaluation of Alternatives/Nine Decision Criteria - Discussion 18
- Protection of Human Health and Environment 18
- Compliance with ARARs 19
- Long-Term Effectiveness and Permanence 22
- Reduction of Toxicity, Mobility, or Volume 23
- Short-term Effectiveness 23
- Implementability 24
- Cost 25
- State Acceptance 25
- Community Acceptance 26
Statutory Determinations 26
Documentation of Significant Changes 27
Figures (following page indicated)
- Figure 1 Location Map 1
- Figure 2 Site Composition 1
- Figure 3 Past Process Operation Areas 3
- Figure 4 Property Ownership at Former Creosote Plant 4
- Figure 5 Contaminated Soil Areas 8
-Figure 6 Areas in Excess of Ground water RCLs/PALs 9
- Figure 7 Floodplain Portion of County Property 13
-FigureS Cross-Section of Cover 16
-Figure 9 Paved Portion of Site 21
-------
Introduction
The eighty-eight acre Moss-American site includes the former location of the Moss-American
creosoteing facility, several miles of the Little Menomonee River - a portion of which flows
through the eastern half of the site - and adjacent flood plain soils (see Figures 1 and 2). The site
is located in the northwestern section of the City of Milwaukee, County of Milwaukee, State of
Wisconsin, at the southeast comer of the intersection of Brown Deer and Granville Roads, at
8716 Granville Road. Approximately 65 acres of the site are undeveloped Milwaukee County
park land. Approximately 23 acres are owned by the Union Pacific Railroad, and are used as an
automobile and other light vehicle transport, loading/unloading, and storage area.
The original ROD for the site was signed on September 27,1990. The ROD addressed the
collection and treatment of contaminated groundwater, excavation and treatment by soil
washing/bioslurry techniques of more highly contaminated soils and sediments, consolidation of
the treatment residuals with and containment of other contaminated soils, and the creation of a
new river channel with subsequent filling in of the existing channel. Exposure scenarios used to
evaluate health risks associated with the Moss-American site were site trespass scenario, river
recreational use scenario, and a residential development scenario.
\
This document amends the original ROD in three limited ways.
Based upon site-specific pre-design treatability work, technical literature, and developments at
certain other creosote sites being addressed under CERCLA, it appears unlikely that the bioslurry
technique can attain soil cleanup standards and that selection of a new combination of
treatment/containment measures so as to attain such standards is warranted. The remedy is
amended to replace the bioslurry reactor with low temperature thermal desorption.
The Risk Assessment scenarios allow for the adoption of removal cleanup standards based on
more realistic site use assumptions with the consequent application of new State ARARs for such
uses. Since a portion of the site is in fact owned by an industrial entity, and since the United
States Environmental Protection Agency (U.S. EPA) has received information indicating that
such land usage classification is apt to continue, it appears appropriate to consider adoption of an
industrial usage exposure scenario for that portion of the site now owned by the Union Pacific
Railroad, provided that the necessary deed restrictions are obtained. There has been industrial
development near this portion of the County property, located on the former wood preserving
facility. Hence, for upland areas of Milwaukee County land which are part of the former
creosote site and which are generally adjacent to Union Pacific property, the removal cleanup
standards may be based on an industrial exposure scenario, if certain deed restrictions and
assurances are secured within 180 days. (If requested, U.S. EPA - after consultation with WDNR
-------
MOSS-AMERICAN
SITE
BROVVNOEERROAD
GOOD HOPEX ROAD
SILVER) SPRING X DRIVE
FIGURE 1
LOCATION MAP
MOSS-AMERICAN
-------
MOSS-AMBQCAN
FACUTY
MUKMJKEE COUNTY
FORMER CREOSOTE PLANT
UTTLE MENOMONEE
RIVER DOWNSTREAM
FROM PLANT
= MOSS-AMERICAN
FACILITY
{FIGURE Z
-------
- may consider a brief extension of this timeframe). Within the former wood preserving facility,
those Milwaukee County lands falling within the floodplain of the Little Menomonee River may
be governed by soil removal cleanup standards based on recreational usage, if certain deed
restrictions are secured. This is consistent with the system of parklands and trails maintained by
Milwaukee County downstream of the former wood preserving facility and as discussed more _
fully in the Park and Open Space plan adopted by Milwaukee County in 1991. If necessary deed
restrictions for a given portion of the site can not be obtained within 180 days from the date of
this ROD Amendment, then the soil removal cleanup standard shall be the residential cleanup
standard as established by NR 720, or the original 1990 ROD remedy shall be carried out.
Due to findings of free product and DNAPLs in the groundwater, U.S. EPA has reconsidered the
appropriate means of containment for treated residuals, from more highly contaminated soils and
sediments, as well as soils with lower levels of contamination. As flushing is no longer
desirable, both the appropriate cover and the manner of addressing State liner and leachate
collection system requirements have been reconsidered.
The lead agency for the remedial action at this site is the U.S. EPA. The State of Wisconsin's
Department of Natural Resources (WDNR) is the support agency. This ROD amendment will
become part of the Administrative Record file established for the Moss-American site.
These changes were precipitated by a more realistic assessment of Site conditions and treatment
effectiveness gained from predesign findings. The treatment technology is being changed to
thermal desorption because the innovative technology selected in the original ROD did not
achieve cleanup standards in predesign tests. Although the topic of thermal desorption was noted
briefly in the Moss-American Feasibility Study, thermal desorption treatment was not considered
in detail in either the Proposed Plan developed in 1990, nor discussed in the original ROD.
U.S. EPA concluded that the public could not have logically foreseen that the Agency might
select this treatment technique in lieu of those previously discussed. In reviewing the soil
treatment, U.S.EPA will consider more realistic risk assessment scenarios, consistent with
current policy, provided new State ARARS can be met. The soil containment system also had to
be reconsidered due to findings of DNAPLs and free product in the groundwater. Predesign field
work at the site verified not only the presence of free-product creosote near the soil/groundwater
interface, but also indicated that such materials are present in relatively large extractable
quantities. Creosote associated with groundwater is a subset of those contaminants known as
DNAPLs. The presence of such materials complicates groundwater management. Groundwater
management has already been directed at efforts to enhance DNAPL removal since 1995 via the
utilization of extraction wells and collection tanks. DNAPL management will continue through
the selection of certain soil zones associated with the presence of free-product creosote for
treatment. Since the degree of subsurface contamination has been found to be considerably
larger than originally envisioned, the permeable cover selected in 1990 will be replaced by an
impermeable cover constructed consistent with ARARs.
-------
Therefore, in keeping with CERCLA section 117,42 U.S.C. § 9617, and section
300.435(c)(2)(ii) of the NCP, 40 C.F.R. § 300.435(cX2)(ii), the lead agency proposed an
amendment to the ROD and allowed the public opportunity to comment on the proposed changes
if such changes alter basic features of the ROD. For the original ROD, a public comment period
was initiated on June 4,1990 and extended to August 6,1990. For the proposed ROD
amendments, a public comment period was initiated on March 9,1998 and was extended to May
8,1998. A public meeting to consider the proposed plan and possible ROD amendments was
held at Vincent High School near the site on March 18, 1998. Approximately 45 members of the
public attended this meeting.
!
A response to the comments received during this period is included in the Responsiveness
Summary, which is a part of this ROD amendment.
The information repository and administrative record are available locally for this site at the Mill
Road Library, which is located at 6431 North 76th Street, Milwaukee, Wisconsin.
Site History
In 1921, the T. J. Moss Tie Company established a wood preserving facility west of the Little
Menomonee River. The plant preserved railroad ties, poles, and fence posts with creosote, a
mixture of numerous chemical compounds, derived from coal tar. While No. 6 fuel oil was also
used, no evidence of pentachlorophenol usage was noted at the Moss-American site. Operations
at a creosote plant often involve storage facilities for both creosote and fuels, a boiler used to
make steam to heat the creosote and aid in application to the wood through usage of heat and
pressure, incoming timber unloading/storage, transportation of timber to the creosote application
facility by rail car, and subsequent storage in a drying area. After these processes were complete,
the treated timbers could be shipped to customers. Potential for release of materials exists
throughout the storage, application, and drying processes. See Figure 3 for an approximate
location on site of where these processes were conducted.
Kerr-McGee purchased the facility in 1963 and changed the facility's name to Moss-American.
The name was changed again in 1974 to Kerr-McGee Chemical Corporation - Forest Products
Division. In 1998, the name of this company changed to Kerr-McGee Chemical LLC; it shall be
referred to as KMC throughout the rest of this document.
From 1921 to 1971, the facility discharged wastes to settling ponds that ultimately discharged to
the Little Menomonee River. These discharges ceased when the plant diverted its process water
discharge to the Milwaukee sanitary sewerage system. Production at the facility ceased in 1976.
-------
OR IP TRACKS
PHOCEUINO AREA
BUBBLE. CONCRETE
POTENTIAL SOLID WASTE PI
FIGURE 3
PAST PROCESS OPERATION AREAS
-------
Under WDNR order, KMC cleaned out eight former settling ponds and dredged about 1,700 feet
of river to remove creosote-contaminated soil and sediment. During 1972 to 1973, three
different dredging efforts were conducted in the Little Menomonee River within the first mile
downstream of the facility.
In 1983, the facility was placed on the National Priorities List (NPL) pursuant to Section 105 of
CERCLA. U.S. EPA initiated a negotiation period with potentially responsible parties (PRPs)
associated with the site to determine if the performance of a Remedial Investigation/Feasibility
Study (RI/FS) would be privately conducted. However, such discussions did not result in
settlement of this matter. Therefore, U.S. EPA determined in 1987 that it would conduct the
RI/FS.
Following development of the 1990 ROD, U.S. EPA again entered into discussions with
potentially responsible parties. On December 30,1991, the United States lodged a consent
decree with the Federal District Court for the Eastern District of Wisconsin in Milwaukee. This
Consent Decree, which was signed by U.S. EPA, the State of Wisconsin and KMC, calls for
implementation of the Remedial Design and Remedial Action set forth in the ROD by KMC.
The County of Milwaukee and the Chicago and Northwester Railroad (later the Union Pacific
Railroad) submitted comments on the Consent Decree. The County of Milwaukee filed
objections to the Consent Decree and sought to intervene in the proceeding in 1992. U.S. EPA
responded to the comments and objections in its 1993 Motion to Enter. The County withdrew its
objections in February 1996, after reaching an agreement with U.S. EPA on past costs. The
decree was entered by the Court in March 1996. See Figure 4 for an indication of current
property ownership at the former creosote plant
Despite limited site access during the 1991-1996 time frame, KMC has moved on with the
accomplishment of certain tasks called for in the Statement of Work made a part of the decree.
These include certain treatability study and predesign tasks examining issues related to verifying
the presence and extent of free-product residues of creosote associated with soils just above the
groundwater table, or as "pools" collecting at the soil/groundwater interface; refining estimates
on the extent of contaminated sediment in the Little Menomonee River; refining estimates on the
extent of contaminated soil on site; and further investigating and evaluating groundwater
conditions on site, notably on the east side of the Little Menomonee River.
Based on the predesign results, U.S. EPA issued correspondence to KMC requesting that initial
priority be given to removing the free product. Design, construction and installationof a removal
system featuring use of extraction wells, conductivity probes to distinguish between creosote and
groundwater, and supplementary storage tanks was undertaken in 1995. In 1997, U.S. EPA
developed and WDNR concurred with issuance of an Explanation of Significant Differences
(ESD) which would allow KMC to utilize an in-situ form of groundwater treatment known as a
funnel and gate system. This involves placement of more porous soils to preferentially direct
-------
\ UNION PACIFIC
\
T '~~i^~^:3^^**Q>#?,.
T
SITE BOUNDARY
600
. 4 cguNty
v^/;>. PROPEBTY i*'?.
x ^< 7
SCALE IN FEET
NOTE LOCATIONS ARE APPROXIMATE.
T V
si
J
I
I
, I
'V
OWNERSHIP .t FORMER CREOSOTE PLANT
-------
groundwater flow, and introduction of air/oxygen, microbes and nutrients, if necessary, so as to
enhance biological degradation of organic contaminants within groundwater. Groundwater
polycyclic aromatic hydrocarbon (PAH) content appears to be mostly the 2-3 ring variety which
may be successfully treated by a biological approach. In contrast, more complex 4-6 ring PAH
compounds are more strongly associated with site soil. Such heavier compounds tend to resist
biological attack. The runnel and gate concept is considered innovative and as such, treatment
results will be monitored by U.S. EPA to gauge treatment efficiency. Design calls for three tiers
of two gates each at which treatment will be provided. Stee] sheet piling will be driven into the
ground near the Little Menomonee River as a further containment aid. Should results indicate
that supplementary groundwater control measures may be necessary, U.S. EPA will require
KMC to conduct further action. The runnel and gate system ^nd in-situ treatment may have an
operation and maintenance cost advantage compared to other more conventional approaches.
Given that the presence of free-product creosote may lengthen the time needed to accomplish
groundwater management goals, which remain unchanged from the 1990 ROD, U.S. EPA
believes it is fair to allow an innovative approach in this circumstance. Design is now final for
groundwater collection/treatment portions of the cleanup project and, in April 1998, U.S. EPA
indicated conditional approval of such design.
If there are discharges to surface water from the remedy, appropriate discharge standards for all
contaminants of concern must be met. These standards are currently being developed
Additional information was required concerning stockpile base pad construction materials and
associated geomembrane liners and protective layers to assure appropriate interim storage of
excavated soils should groundwater construction commence ahead of soils treatment portions of
the remedy. U.S. EPA and WDNR have worked with KMC concerning such details, and upon
receipt of further details submitted in June-July 1998, U.S. EPA indicated approval of temporary
stockpile design on July 27,1998.
Changes to the Remedy
Thermal Desorption and Bioslurry Consideration
The soil treatment technology is being changed because the bioslurry technique may not be able
to achieve the treatment cleanup levels set forth in the ROD.
The treatability study concerning the projected removal efficiency of the bioslurry technique
indicates, for samples analyzed, that total PAHs were reduced from levels of 1100-1600 mg/kg to
around 320 mg/kg, and that carcinogenic PAHs (CPAH) were reduced from a range of 390-550
mg/kg to around 170 mg/kg. This means that there could be considerable difficulty in attaining
-------
the performance goal of 6.1 mg/kg CPAH established in the 1990 ROD. The administrative
record indicates (see notes of Brown Wood Preserving discussion) that other creosote sites have
had difficulty achieving single-digit part per million CPAH levels with biodegradation
techniques. Qualitatively, treatment techniques such as biodegradation for creosote
contaminated soils tend to most successfully attack the 2 and 3 ring member, and to some degree
the 4-ring PAH compounds, while being far less successful with the 5 and 6-ring PAH
compounds.
A portion of the PRP data (see site bioslurry treatability pilot report, administrative record update
#5 document # 37, August 1993) seems to support this pattern. There occurred a marked drop
off in removal efficiency in dealing with the more complex BAH ring compound
benzo(k)fluoranthene, as opposed to the simpler ring compounds noted elsewhere in that report.
U.S. EPA has made similar findings at other wood preservative sites, (see administrative record
notes concerning the sites L.A. Clarke & Sons - Virginia and American Creosote Works -
Florida)
Some reports obtained from the Gas Research Institute discuss thermal desorption processes used
to treat contaminants at manufactured gas plant sites. Because of the similarity of contaminants
between such sites and creosote facilities, adoption of such treatment techniques at creosote sites
such as Moss-American may be warranted. These reports also contained references which
indicated that a possible limiting factor in the application of water-based biodegradation
techniques to PAHs is the inadequacy of the process in desorbing PAH contaminants from soil
particles into solution where they can be metabolized by the biological process.
In 1992, U.S. EPA first began to issue policy papers regarding a concept known as presumptive
remedy. In 1995, U.S. EPA's Office of Research and Development developed a paper indicating
that thermal desorption was regarded as one of the presumptive remedies for a wood preserving
Superfund site such as Moss-American. As the U.S. EPA's experience has grown, noticeable
patterns have begun to emerge with regard to pollutants found at certain types of sites,
concerning expected similar contaminant effects, and relative degrees of success in dealing with
such contaminants. Presumptive remedies build on this experience, and represent approaches
which can be chosen with a fair degree of confidence regarding their application at a given class
of site. One advantage in utilizing the presumptive remedy approach is that it can shorten and
simplify site investigation, feasibility study, and remedy selection efforts.
In October 1997, U.S. EPA issued a document entitled "Treatment Technology Performance
Data for Remediation at Wood Preserving Sites." This document examined removal efficiencies
realized by a wide variety of treatment technologies at wood preservative sites in both the U.S.
and Canada. Of particular interest was an examination of the results of bioslurry treatment of
creosote contaminated soils at a site in Mississippi compared to the treatment efficiency results
utilizing thermal desorption technology at a Canadian creosote site. Results indicated that for the
-------
more complex CPAH compounds of indeno(l,2,3-cd)pyrene, benzofluoranthene (two varieties),
and benzo(a)pyrene, biosluiry treatment yielded a removal efficiency of from 33-39 percent. In
comparison, thermal desorption removal efficiencies were at 99.9 percent for these same
compounds. These compounds are of interest because they constitute four of the eight
carcinogenic PAH compounds of concern identified at the Moss-American Site.
KMC has had experience utilizing the thermal desorption technique at other creosote sites where
waste management has been required. KMC has submitted results concerning the degree of
contaminant removal efficiency to U.S. EPA. These results indicate a range of 95-98 percent
removal efficiency predicted. Hence, while all site conditions are not replicable, there is a basis
by which U.S. EPA may predict that employment of the therrnal desorption technique has a
reasonable opportunity for a successful outcome.
The amended remedy will utilize the technique of thermal desorption for on-site treatment of
contaminated soils/sediments. To differentiate this treatment technique from conventional
incineration, thermal desorption has as its objective the driving off of contaminants from the
waste mass, rather than the destruction of such contaminants. There is no combustion in the
primary unit of the waste itself. Instead some portion of the organic contaminants are volatilized
and then the gases driven off undergo further treatment, such as through an afterburner,
condenser, or sorption unit It should be noted that if the influent contaminated soil could be
classified as a hazardous waste, and if the resultant contaminant-containing gases are managed
via flare or afterburner, then that flare or afterburner must achieve the removal efficiency of
99.99 percent as would be expected of appropriate emission control involving hazardous waste
combustion. In thermal desorption, the temperature 600 degrees Fahrenheit (F) is seen as
something of a "breakpoint." Below this temperature, it is assumed that the main application is
for volatiles. From 600-11 SO degrees F, semivolatiles, PAHs, and PCBs are being attacked, also.
At the Canadian site discussed previously, the operating temperature was 900 degrees F at 85
minutes retention time. 1150 degrees F is considered about the upper range for thermal
desorption application. At these lower temperatures, compared to the temperatures of some
2200-2300 degrees F realized in a full incineration unit, metals such as lead do not volatilize,
making an easier emissions control situation. After thermal desorption treatment, the residuals
are soils, not ash. Unfavorable site characteristics include excessive clay/silt content in the soil,
many large diameter rocks, and excessive moisture content - since energy is wasted driving away
water.
One possible solution to deal with soils with higher than desirable clay/silt content is to mix in
coarser soils prior to treatment. Thermal desorption is best applied when the organic
contaminants do not make up more than 10 percent of the soil matrix. After treatment, dust
generation may become a problem, so water is added to dampen the treated material. To prevent
combustion, sometimes an inert gas such as nitrogen is injected countercurrent to the flow of
treated material. Following treatment at projected removal efficiencies, the residual soils shall be
-------
suitable for replacement on site. Prior to commencing operation, treatability study or predesign
work may be necessary to define optimum operating conditions.
Cost data gathered with regard to thermal desorption application at the Moss-American site
indicates a range of approximately $75-100 per cubic yard. Some 20-30,000 cubic yards of the.
more highly contaminated site soils and sediments are expected to undergo treatment using this
technique. In comparison, the cost of a bioslurry treatment system for the site was recently
estimated at $150-200 per cubic yard.
Areas to Undergo Thermal Desorption
1
Site soil areas to undergo thermal desorption treatment would be selected for one of three
reasons: 1) Direct contact "hot spots" (> 78 mg/kg CPAHs ( approximately 78 parts per million
(ppm)), 2) groundwater contaminant source areas having the presence of free-product creosote,
and 3) soils containing contaminants exceeding Wisconsin generic residual contaminant levels
(RCLs) for benzene/toluene/ethyl benzene/xylene (BTEX) and PAHs in soils which pose a
source threat in attaining groundwater cleanup goals. It should be noted that these BTEX
compounds occur less frequently and at levels well below CPAH compounds. However, such
compounds will be considered in an effort to comply with soil cleanup standards developed since
the original ROD. Residual contaminant levels (RCLs) in soils of 1.5 ppm for toluene, 2.9 ppm
for ethyl benzene, 4.1 ppm for xylene, 5.5 ppb for benzene and for three PAH compounds: 0.4
ppm for naphthalene, 100 ppm for fluorene, and 48 ppm for benzo(a)pyrene are considered to
pose no further threat as a source of contaminants to groundwater. Accordingly, U.S. EPA
hereby adopts these RCLs for this Site. More darkly shaded areas depicted in Figure 5 indicate
areas which may undergo thermal desorption treatment according to discussion in this paragraph,
however, this figure may not represent the full aerial extent accurately, so further discrete soil
sampling will be necessary to define these areas prior to excavation.
Additionally, it is also appropriate to consider the implications of groundwater monitoring results
now being conducted quarterly since the commencement of remedial action work at the site.
Results received in June 1998 indicate that while many groundwater monitoring wells at the
Moss-American site are relatively free of significant contaminant levels, three wells indicated
notable groundwater contamination. These wells are MW-4S, MW-7S, and TW-09. Under NR
140, preventive action limits (PALs) have been established for three PAH compounds -
naphthalene (PAL of 8 ppb), fluorene (PAL of 80 ppb), and benzo(a)pyrene (PAL of 0.02 ppb).
Naphthalene levels at these three monitoring wells were particularly high, with concentrations of
2080 ppb at MW-4S, 6470 ppb at MW-7S, and 3080 ppb at TW-09. Residual contaminant levels
of 0.4 ppm, 100 ppm, and 48 ppm have been established for groundwater protection for
naphthalene, fluorene, and benzo(a)pyrene, respectively. U.S. EPA also adopts these RCLs at
the Site. In addition to the areas discussed in the previous paragraph as requiring thermal
treatment, U.S. EPA makes note of the following points from Remedial Investigation sampling
-------
FIGURE 5
CONTAMINATED SOIL AREAS
Darker hash marks indicate soil areas to undergo thermal desorption treatment
Lighter hash marks indicate soil areas to be excavated, consolidated and contained
along with treated soil residuals.
-------
for surface soils where levels of PAHs discussed in this paragraph pose a threat of further
groundwater contamination:
SS012 - naphthalene 57 ppm
SS015-naphthalene 3.5 ppm
SS018-naphthalene 38ppm benzo(a)pyrene 180ppm
SS030 - naphthalene 1800 ppm fluorene 1700 ppm benzo(a)pyrene 230 ppm
SS03 8 - naphthalene 530 ppm fluorene 150 ppm
SS064 - fluorene 480 ppm benzo(a)pyrene 200 ppm
SS089-naphthalene 1500 ppm fluorene 1100 ppm
SSI 13-naphthalene 660ppm fluorene 950ppm benzo(a)pyrene 160ppm
There were exceedances of RCLs for groundwater involving two volatile organic compounds at
two of the points just discussed. At SS089, xylene(s) were found at a concentration of 14 ppm
compared to the groundwater RCL of 4.1 ppm. At SS030, benzene was detected at a
concentration of 100 ppb, compared to the groundwater RCL of 5.5 ppb.
Approximate location of these points is provided in Figure 6. U.S. EPA notes that there may
indeed be some overlap of areas to undergo thermal desorption between Figures 5 and 6.
However, further discrete soil sampling should be conducted before treatment occurs in areas of
the site that may not have been adequately characterized by past sampling efforts to determine if
groundwater RCLs are currently exceeded and after treatment in the excavated areas to ensure
that unacceptable threats to groundwater have been successfully addressed through attainment of
the groundwater RCL.
U.S. EPA observes that successful thermal desorption treatment is a two-step process where first
treatment must attain either the appropriate contaminant range or the pertinent reduction removal
efficiency depending on the initial threshold value for the contaminant type in question.
Achieving this degree of treatment ensures successful compliance with the treatability variance
values as further discussed in the "Treatability Variance Adjustment" section of this document.
A second step involves comparison to the residual contaminant level for compounds
promulgated under NR 140. Attainment of the groundwater RCL allows designation of a
CAMU, whereby soils can be disposed without a liner and leachate collection system.
Because of the linkage between certain RCLs and PALs, U.S. EPA hereby adopts promulgated
PALs for naphthalene, fluorene, and benzo(a)pyrene as supplementary groundwater restoration
ARARs in addition to the BTEX compounds previously cited.
-------
Ir-clutstr y
Fan,
onitoring Rtlulls
J/98 Monitoring Results - TW09 (ppb)
Benzene 2
Naphthalene 3080
Benzo(a)pyrtne 20.3
:lontl»»i A,.,
SS11} - naphthalene 660 ppm
fluortne 950 ppm
beiao(a)pyrene 160 ppm
Benzene j
Naphthalene 6470
SSOI5 - naphthalene 3.5 ppm*
/
SS038 naphthalene 530 ppm
fluortne ISOppm
SS0/«- naphthalene 38 ppm
bensotaipynmlWppm
v<'
SS030 naphthalene 1800 ppm
fluortne 1700 ppm
berao(a)pyrene 230 ppm
SSOI2-naphthalfm 57 ppm
SS089 - naphthalene 1500
fluorent 1100
benxo(a)pyrene 200 ppm
CICtMO
SITE KXINOARV
UDU
_ SAMPLE LOCATION . MIOHEST CONCENTRATION USED IF MOW
THAN ONE SAMPLE WAS TAKEN AT A SAMPLE LOCATION
^-SAMPU NUMBER
SSOKT
4 OQQ CONCENTRATION IN UtVKQ INUMBER IN PARENTHESES
DENOTES JO ( ()AI( CONCl.:NTRAT,ON AT n)1.:
SAMl>l.rNC fOIKJ
Residual Contaminant Levels - GrounJwater Protection Component (ppm)
\uphihalene 0 4
f'luorene 100
Bemo(a)pyrene 4$
1'iiluene I 5
\\lene(s> 4 I
hthylkenzene 2V
llt-n:,'m 01105)
HI,I tO. 6
AIU AS 10 I:XCKSS uf (;KOI:M)\VATKR KCI.S/PALS
3/98 Monitoring Results MW-4S (ppb)
Benzene 10
Naphthalene 2080
Fluorene 368
Beruo(a)pyrene 25.3
PAU (ppb)
Benzene o.S
Toluene 6,16
Elhylhenzem- 140
Xylene(s) 124
Huortne ,10
lkniu(a)f>yr,-nr IIII.'
-------
10
Allowance for Adoption of Industrial or Recreational Exposure Scenarios for Soils Risk
Consideration
If requisite deed restrictions are secured within 180 days of the date of this ROD, EPA will allow
residual levels based upon nonresidential scenarios. If requested, U.S. EPA - after consultation
with WDNR - may consider a brief extension of this timeframe.
At the time of development of the original ROD for the Moss-American site, exposure scenarios
were developed so as to describe potential human exposures for current and potential site uses
and conditions. These scenarios considered degree of risk posed through exposure to site
contaminants via site trespassing, river recreational usage of the site, and the possibility of
residential development of the site.
Industrial Usage
A risk scenario that was not explored during development of the original ROD was the risk posed
to an industrial worker at the site, and what the level of cleanup appropriate to protect such a
user.
Since about 1980-1981, and continuing to the present time, the Union Pacific Railroad has
utilized the western 23 acres of the site for an automobile and other light vehicle transport,
loading/unloading, and storage area. Much of the Union Pacific property has been paved with
asphalt.
Since the time of the original ROD development, U.S. EPA has instituted a series of
administrative reforms associated with Superfund sites designed to make remediation more fair.
In October 1995, U.S. EPA announced certain administrative reforms intended to ensure that risk
assessments are grounded in reality and make use of "real world" information about the site.
Since a portion of the site is in fact owned by an industrial entity, and since the Agency has
received information indicating that such land usage classification is apt to continue, it is
appropriate to consider adoption of an industrial usage exposure scenario for that portion of the
site now owned by the Union Pacific Railroad. In correspondence received from the Railroad,
that entity has indicated its willingness to enter into written deed restrictions so as to preclude
residential development of lands it owns, and limit its usage to an industrial use. Chapter NR
700, Wis. Adm. Code, series requires the use of deed instruments where soil contaminants above
levels that would be acceptable for residential use remain at a site so the remedy is protective of
human health. U.S. EPA therefore expects KMC to pursue such deed restrictions from Union
Pacific, which would have the effect of limiting future land development on this site parcel to
industrial usage. If applicable restrictions are secured, the Union Pacific property can be
considered as industrial. If such deed restrictions are not secured within the expected 180 days
timeframe after the effective date of this amendment, then the residential scenario and cleanup
-------
11
standards for direct contact user protection established by NR 720 shall be obtained or the
original 1990 ROD standards shall be met.
The other major site property owner is Milwaukee County. For purposes of this ROD
amendment, U.S. EPA will categorize Milwaukee County property associated with the site into
two portions as noted in the site consent decree between the United States and Milwaukee
County. Appendix 2 of that decree denotes the former creosote plant and the Little Menomonee
River and its floodplain downstream from the plant as comprising the Moss-American facility.
This ROD amendment will deal only with that portion of Milwaukee County property that is part
of the former creosote plant. U.S. EPA may make a determination on land usage along the Little
Menomonee River and its floodplain downstream from the plant at a later date.
The County property at the former creosoteing plant is located adjacent to the Union Pacific
property. U.S. EPA is aware that in 1997 an easement was sought concerning a portion of
Milwaukee County property on the "former creosote plant" area for which industrial
development was projected. In addition, the decree between the United States and Milwaukee
County provided that there would be no residential use of the former wood preserving plant
property during the implementation of the remedy. A Park and Open Space plan adopted by the
County in 1991 calls for enhanced recreational opportunity in river corridor settings such as the
Little Menomonee. Hence, for the former creosote plant, U.S. EPA considered industrial and
recreational scenarios. For non-floodplain areas on Milwaukee County property located on the
former creosote plant, U.S. EPA believes an industrial exposure cleanup scenario is appropriate,
providing necessary deed restrictions are obtained in accordance with ch. NR 720 within 180
days. This is consistent with nearby uses and potential development. A worker engaged in
industrial activity on the site would be most likely to be affected by the direct contact pathway
for contaminants associated with site soils. As noted above for Union Pacific deed restriction
discussion, U.S. EPA would therefore expect KMC to pursue such deed restrictions from
Milwaukee County as well. If KMC obtains such deed restrictions consistent with NR 720, U.S.
EPA will adopt an industrial scenario for this property. If execution of such deed restriction is
not possible within the expected 180 days timeframe after the effective date of this amendment,
then the residential scenario and cleanup standards for direct contact user protection established
by NR 720 shall be obtained or the original 1990 ROD remedy shall be carried out. A deed
restriction limiting future land use to recreational use would be required under ch. NR 720. U.Sr
EPA would also insist that deed restriction as a part of appropriate institutional control under
CERCLA for the floodplain portion of the former creosote plant in order to protect users of this
portion of the site from an unacceptable direct contact risk.
-------
12
Remediation Levels - Industrial
In considering a new exposure scenario, it is also appropriate to consider developments in
pertinent soil cleanup levels which have been promulgated since the original ROD. Effective
April 1,1995, the State of Wisconsin promulgated Chapter NR 720 concerning soil cleanup
standards. The purpose of this particular chapter is to establish soil cleanup standards for the ~
remediation of soil contamination. Chapter NR 720 requires that all soil contaminant pathways
be addressed, which include air, groundwater, surface water, and direct contact.
Calculations done under Chapter NR 720 indicate soil cleanup must be performed to the level of
3.1 mg/kg (or ppm) of total carcinogenic PAHs for an industrial usage scenario so as to minimize
any excessive direct contact threat posed to such a site user. Interim Guidance as noted in
WDNR Publication RR-519-97 indicates alternatives to the direct use of generic RCLs for
individual PAHs may be appropriate and acceptable in some cases, such as establishing RCLs for
the direct contact pathway. Hence, U.S. EPA believes it is appropriate to utilize an overall total
PAH approach, rather than listing individual direct contact RCLs in this instance. If obtaining a
deed restriction from a given property owner is not possible within the expected 180 days
timeframe after the effective date of this amendment, then the direct contact total CPAH value
considered protective for residential usage is 1.9 ppm. Discussion has already been provided in
the section on Thermal Desorptkm and Bioslurry Consideration as to U.S. EPA's expectations
regarding pertinent compounds and levels to be attained such that potential source threat to
groundwater is properly managed.
Background Considerations - Soil and Sediment
Amendment of the original residential cleanup value for direct contact threat, calculated at 0.061
ppm for the site at the time of the original ROD, is appropriate for another reason. Since that
time, U.S. EPA has received information (see administrative record WDNR information on
soil/sediments) that there is a notable distinction between background CPAH levels which may
be expected in urban versus non-urban areas. Literature sources indicate that in general a range
of 1-4 ppm CPAH represents background soil conditions for an urban area such as Milwaukee.
On a site specific basis, Predesign Task # 2 indicates that the background soil CPAH range for
the Moss-American site is from 0.46-3.5 ppm. Hence, it is not realistic to expect cleanup to a
level which in all likelihood cannot be attained or sustained in such a setting. This ROD
amendment views that all discussions herein concerning exposure assumptions, soil standards
and management schemes outlined apply to a site area designated as the "Northeast Landfill" as
well as other site areas.
At the time of the 1990 ROD, a "to be considered" value of 3 ppm as a sediment quality criterion
for CPAH in sediments was derived. However, both the ROD and the consent decree noted that
this value could be subject to change pending investigation of what might constitute a maximum
probable background (MPB) value, and to utilize the higher of those values. Considering the
-------
13
urban setting of the Little Menomonee River in the vicinity of the site and the sampling and
analysis work done to establish the MPB, the WDNR has informed U.S. EPA (see March 4, 1998
correspondence) that it now believes a value of 15 ppm CPAH represents a reasonable sediment
MPB for the Little Menomonee River.
U.S. EPA believes that a dynamic situation exists between the Little Menomonee River and its
floodplain. This means that surface soils having excessive CPAH concentrations could be
viewed as a possible threat to attainment of sediment quality goals. In the same way, deposition
from the river could contaminate the floodplain, and consideration of realistic expectation of
post- sediment management remediation must be made concerning any further floodplain
remediation. U.S. EPA notes that only a very small portion of the site floodplain is likely to be
affected by the current ROD amendment - namely that portion which is also a part of the former
wood preservative facility. See Figure 7 in contrast to Figure 2. For this portion of the
floodplain, EPA will adopt a removal cleanup level of 15 ppm CPAH if appropriate deed
restrictions are secured within 180 days of the effective date of this ROD amendment.
Recreational usage of the Site
As noted above, a Park and Open Space plan adopted by the County in 1991 which calls for
enhanced recreational opportunity in river corridor settings such as the Little Menomonee. For
Milwaukee County property which is located in the floodplain of the Little Menomonee River.
and is a part of the former creosote plant, U.S. EPA believes that a recreational exposure scenario
may be applied. This is consistent with the system of parklands and trails maintained by
Milwaukee County downstream of the former wood preserving facility. Industrial development
is not likely within the floodplain. Applying the procedures in NR 720 to determine a site-
specific RCL, a cleanup level of approximately 49 ppm CPAH provider sufficient direct contact
protection for the recreational user. However, U.S. EPA will not adopt 49 ppm CPAH as the
cleanup value for County-owned floodplain land on the former creosote plant. Chapter NR 720
series requires the soil to surface water pathway be addressed. After considering needed erosion
control measures and sediment remediation values, U.S. EPA adopts a figure of 15 ppm CPAH
to be the surface water RCL for the entire former creosote plant and the recreational cleanup
value for the County owned portion of the site in the floodplain.
NR 216 substantive requirements, including the development of an erosion control plan, would
apply during construction stages of the work. To be considered after construction would be
suitable measures to control soil erosion to prevent transport of contaminated soil from all
disturbed areas on the entire site. For all disturbed areas that will not be covered to prevent
direct contact exposures, such measures may include, but are not limited to, placement of 6" of
topsoil and the establishment of a good vegetated cover and/or the collection and management of
all runoff from those areas in units such as sedimentation basins.
-------
Wetland
CALf m MET
FIGURE?
FLOODPLABV PORTION
COUNTY PROPERTY on
FORMER CREOSOTE SITE
-------
14
As was previously discussed for needed deed restrictions for industrial land usage, U.S. EPA
would expect KMC to pursue recreational deed restrictions from Milwaukee County as well. If
execution of such deed restriction is not possible within 180 days after the effective date of this
amendment, then the residential scenario and cleanup standards for direct contact user protection
established by NR 720 shall be obtained or the original 1990 ROD remedy shall be carried out._
Permeable Soil Cover - Waiver Withdrawal and Establishment of a CAMU
At the time of original development of the remedy, a waiver under Section 121(d)(4)(B) of
CERCLA 42 U.S.C. was invoked for State requirements dealing with design, operation, and
closure of hazardous waste landfills. The State of Wisconsin concurred with that waiver. The
reasoning behind the waiver in the 1990 ROD was that placement of an impermeable cap over
the mass of treated/untreated soil, sediment and debris would result in greater risk to health and
the environment by significantly prolonging the time it would take to achieve groundwater
management objectives. In such a situation, the remedial action's effectiveness in reducing risk
would be in question. It was reasoned that a permeable cover would enhance groundwater
remediation by encouraging a flushing action.
However, predesign field work at the site in 1994 verified not only the presence of free-product
creosote near the soil/groundwater interface, but also indicated that such materials were present
in relatively large extractable quantities. The presence of such materials complicates
groundwater management.
At the Moss-American site, the greatest concentrations of free-product creosote are located near
monitoring wells MW-8S and TW-07. The area between these two wells is approximately 1 acre
in size. Predesign sampling done in 1994 indicated that free-product creosote was present at
depths between 6 and 12 feet below the ground surface. The free product recovery system
installed by KMC in 1995 has recovered approximately 10,000 gallons of concentrated creosote
plus oily wastewater thus far. It has also been explained earlier in this document that one of the
primary reasons for selecting a given soil area for thermal desorption treatment is that soil's
association with free-product creosote. Soil areas to undergo treatment for reasons other than the
presence of free-product are expected to undergo excavation to a working depth of four feet.
However, those soil areas associated with free product will be excavated to a depth of about 9-10
feet, unless there is obvious indication of a "hot spot" free-product area extending below the
groundwater table in which case efforts to remove free-product will continue. Verification
sampling after initial excavation and treatment will refine final excavation depths. A revision to
the groundwater remedy under an Explanation of Significant Differences (ESD) was adopted in
1997 that includes containment components utilizing sheet wall with in-situ treatment of the
groundwater. This will effectively minimize the spread of contaminants and DNAPL materials
in the soils and groundwater regardless of the amount of infiltration into the contamination zone.
Therefore, the need for allowing flushing is minimized, the groundwater restoration should be
-------
15
relatively unaffected by the amount of infiltration allowed through a cover system and the design
of any cover system should be based on what is protective of human health and the environment
given the nature of the material to be covered and complies with ARARs. Therefore, the
following cover designs shall be utilized:
A. Soils picked up for treatment, which include soils that exceed the NR 720 groundwater RCLs
for the BTEX and PAH contaminants, >78 mg/kg CPAHs, to be contained after
treatment to at least groundwater RCL levels for all contaminants or less, provided appropriate
deed restrictions and maintenance agreements are obtained within the expected 180 days
timeframe after the effective date of this amendment:
t
Section NR 504.07 cover (CAMU reconsolidation disposal unit)
B. Soils left in place that do not exceed the criteria under A, but exceed NR 720 direct contact
RCLs for the land use at that portion of the site, provided appropriate deed restrictions and
maintenance agreements are obtained within the expected 180 days timeframe after the effective
date of this amendment (There is also an option to pick up, and, if necessary, treat these soils and
consolidate them in the CAMU reconsolidation area):
Existing (as of the effective date of this amendment) asphalt pavement or 2 feet of clean soil and
6 inches of vegetated topsoil (NR 720 performance standard covers for in place soils)
Soils in the floodplain under B. that remain in place and exceed the direct contact RCL for
recreational usage shall be covered with 2 feet of clean soil and 6 inches of vegetated topsoil,
provided appropriate deed restrictions and maintenance agreements are obtained within 180 days
after the effective date of this amendment, and provided that the necessary floodplain easements
are obtained for filling in the floodplain. If the floodplain easements cannot be obtained, these
soils shall be removed so that the remaining soils may not exceed the NR 720 residential direct
contact RCL values for all the contaminants of concern. This timeframe may be extended upon
the approval of U.S. EPA in consultation with the WDNR.
C. (Alternative to A only) Soils under A, which would all be picked up and treated to at least
direct contact levels and groundwater RCLs specified in this amendment for all contaminants or
less provided appropriate deed restrictions and maintenance agreements are obtained within the
expected 180 days timeframe after the effective date of this amendment:
Six inches of vegetated topsoil (CAMU reconsolidation disposal unit)
D. Soils under A and soils under B are required to all be picked up and treated to at least direct
contact levels specified in this amendment for all contaminants or less if appropriate deed
-------
16
restrictions and maintenance agreements are not obtained within the expected 180 timeframe
days after the effective date of this amendment:
Six inches of vegetated topsoil (CAMU reconsolidation disposal unit)
The design of the s. NR 504.07 cover system includes a clay cap (approximately 24 inches thick)
topped with a suitable frost-protection soil layer (approximately 18 inches thick) A cross-section
of such cover is depicted in Figure 8.
While Section 3004(o) of RCRA, 42 U.S.C. 6924(o), only requires a double-liner and leachate
collection system for new, replacement or expanded landfills, the authorized State requirements
at Wis. Admin. Code. s. NR660.13(10) (formerly 181.44(10X4), 42(8) and 44(13)) also require a
double liner and leachate collection system for existing landfills.
U.S. EPA and WDNR have previously determined that certain wastes on the Moss-American site
are listed under the Resource Conservation and Recovery Act as hazardous wastes K001 and
U051. RCRA requirements are considered applicable if, as established in the WDNR NR 600
rule series, activities being considered as part of the remedy constitute treatment, storage, or
disposal as defined by RCRA. Excavation and disposal activities will require compliance with
RCRA waste management standards.
The CAMU rule within RCRA, at 40 CFR 264 Subpart S [264.552], however, allows movement
of contaminated material within an area of contamination without triggering requirements for
"generated" hazardous waste. In essence, this allows consolidation of contaminated soils and
sediments containing listed or characteristic waste without triggering the land disposal restriction
or minimum technology requirements (MTRs) of RCRA. This concept is needed for an
alternative such as that featured in this ROD amendment where consolidation from several points
around a site is expected to occur followed by containment under a cover.
Wisconsin has adopted the CAMU rule in NR 636. A key criterion for establishing a CAMU in
NR 636.40(3)(b) states that for waste management activities associated with the CAMU, there
may not be the creation of unacceptable risk to humans and the environment from exposure to
hazardous waste or its constituents. Contaminated soil and sediment areas depicted on Figures 5
and 6 constitute a CAMU for the site. Should the s. NR 504.07 cover be used (A., above), the
CAMU reconsolidation disposal unit would be designed to be as small as possible to minimize
the cost of a new cover system, so the disposal unit should be located within the CAMU, but will
be considerably smaller than the areas depicted on these figures.
U.S. EPA observes that while the thermal desorption treatment technique may be successfully
employed as a means of dealing with PAH materials in sediments, it will be necessary to
determine if other potential contaminants such as heavy metals and organics are present and
-------
over Descriptions
Amendment Featuring
Thermal Desorption Treatment
Vegetation
6"
s S X**' -." * ' - 'S^^Js'jj *M . S *.-S*
^^^W^mmW^^^^W^^^
^^^m^^n^^^^^^
.-. "' *' "/ . " '" -'"' .."' ...
6"
x Residuals - Lesser .
!< Contaminated Soils !<
FIGURE 8
-------
17
would require attainment of RCLs pertaining to such compounds before containment could
occur. If it is not possible to achieve the RCLs for these contaminants, then the sediments will
have to be managed off-site at a permitted or licensed hazardous waste facility or U.S. EPA may
consider issuing an ESD to change the design of the CAMU redisposal unit to include a liner and
leachate collection system.
In summary, the original underlying premise of invoking a waiver for what normally would have
been installation of an impermeable cap is no longer valid. The theory that promoting a flushing
action so that groundwater management may only be required for a relatively few years is no
longer correct. In utilizing the CAMU as allowed under federal and State law, a liner and
leachate collection system is not necessary. Provided the groundwater component of the RCL
for the BTEX compounds,|naphthalene, fluorene, and benzo(a)pyrene arejattained, a CAMU is
appropriate for this Site. Treated sediment may contain other contaminants that would also need
to meet groundwater RCLs or the sediment will have to be managed off-site unless an ESD is
issued for changing the design of the CAMU disposal unit to include a liner and leachate
collection system.
Unlike some materials which undergo relatively rapid decomposition and which may be disposed
through the technique of land disposal, more complex PAH compounds may undergo
degradation slowly unless specific steps are taken to hasten the process. Hence, U.S. EPA will
require cover maintenance to extend into perpetuity.
Treatability Variance Adjustment
The 1990 ROD contained Table 3, which discussed treatabiliry variance concepts. In order to be
acceptable for land disposal, threshold concentrations for certain constituents of concern were
established. If the concentration of a given contaminant exceeded that threshold value, then it
had to be treated so as to achieve an appropriate removal efficiency range. If the initial
concentration were below the threshold value, then an acceptable post-treatment concentration
range may be specified. Table 3 listed various contaminants of concern, and provided expected
reduction efficiencies or post-treatment concentrations viewed as acceptable for land disposal.
Based on subsequent guidance, "Obtaining a Soil and Debris Treatability Variance for Remedial
Actions", Superfund Publication # 9347-3-06FS, as well as further insight as to what should be
considered contaminants of concern at the site, U.S. EPA modifies the table as follows:
- Benzene and ethylbenzene were not previously listed. U.S. EPA adds these constituents, and
notes that like toluene/xylene previously listed, land disposal is appropriate if treatment reduces
concentration by 90% or to below 10 ppm, pending initial contaminant status regarding a
threshold value of 100 ppm. Utilizing the CAMU concept discussed elsewhere in this document,
in order for these volatile compounds to undergo land disposal without further aid of liner or
leachate collection system, the groundwater RCL of 1.5 ppm for toluene, 4.1 ppm for xylene(s),
-------
18
2.9 ppm for ethylbenzene, and 5.5 ppb for benzene must be attained. Upon review of soil
concentrations found in the Remedial Investigation for these substances, and given the expected
reduction efficiency of the thermal desorption technology, U.S. EPA believes these values may
be achieved.
- No threshold value was provided for carcinogenic PAH. The guidance document cited above
lists 400 ppm for PAHs as the threshold value. A reduction efficiency of 90% was cited
previously. The guidance document now cites 95% removal efficiency for substances exceeding
the threshold value, and an acceptable range of 0.5-20 ppm for substances falling below the
threshold value. This will replace the 6.1 ppm figure cited in Table 3.
i
- Fluorene had not been previously listed as a contaminant of concern. U.S. EPA is hereby
adding fluorene as a contaminant of concern.
- Utilizing the CAMU concept discussed elsewhere in this document, for the PAH compounds
naphthalene, fluorene, and benzo(a)pyrene, these compounds may undergo land disposal without
further aid of liner or leachate collection system provided that they fall below their respective
groundwater RCLs of 0.4 ppm, 100 ppm, and 48 ppm. Upon review of soil concentrations found
in the Remedial Investigation for these substances, and given the expected reduction efficiency
of the thermal desorption technology, U.S. EPA believes these values may be achieved.
Evaluation of Alternatives
The following section outlines the nine decision criteria that were used to evaluate the original
selected remedy and the amended remedy. Based on current information, the amended remedy
provides the best balance of benefits measured against these decision criteria. This section
discusses the anticipated performance of the amended remedy compared to the decision criteria.
1) Overall protection of human health and the environment
This criterion addresses whether or not an alternative provides adequate protection of human
health and the environment and describes how risks are eliminated, reduced or controlled through
treatment, engineering controls, or institutional controls.
Comparative Analysis
a. Change in Soil Cleanup Level for Portions of the Site
Information in the Administrative Record indicates that employment of an industrial or
-------
19
recreational usage scenario for respective portions of the site is justified, because of indications
that such usage is likely or will continue into the foreseeable future. Appropriate deed
restrictions will be required to ensure that the land usage remains industrial or recreational.
Compared to residential usage, industrial and recreational usages involve less frequent number of
instances of exposure per unit time. Hence, risk assessment involving an industrial/recreational
exposure scenario will result in calculation of an acceptable contaminant concentration higher
than a residential scenario. Adoption of such scenario for the site seems justified in this instance,
since the amended remedy still maintains overall protection to human health and the
environment. If necessary deed restrictions for a given portion of the site can not be obtained
within 180 days from the date of this ROD Amendment, then the soil removal cleanup standard
shall be the residential cleanup standard as established by MR, 720, or the original 1990 ROD
remedy shall be carried out.
b. Means of Soil Treatment
The overall remedy involves a combination of treatment/containment methods so as to achieve
performance standards. The amended remedy employs a different means of soil treatment, i.e.,
thermal desorption versus bioslurry, than the originally selected remedy. The expected reduction
in contaminant levels to be brought about by usage of thermal desorption, coupled with other
remedy provisions, should ensure that the criterion of protection of human health and the
environment is maintained.
c. Revoking of the Waiver of RCRA Subtitle C Cap Requirements Regarding Treated
Soils/Sediments Residuals and Less Contaminated Soils
A waiver of the need to utilize RCRA Subtitle C cap requirements was invoked at the time of
original ROD development. At that time it was reasoned that placement of an impermeable cap
over the mass of treated/untreated soil, sediment and debris would result in greater risk to health
and the environment by significantly prolonging the time it would take to achieve groundwater
management objectives. It was reasoned that a permeable cover would enhance protectiveness
by the relatively prompt groundwater remediation which might be encouraged through a flushing
action.
However, predesign field work at the site in 1994 verified not only the presence of free-product
creosote near the soil/ground water interface, but also indicated that such materials are present in
relatively large extractable quantities.
The presence of such free-product creosote in quantities significantly larger than contemplated in
the original ROD makes relatively prompt attainment of groundwater remediation goals
doubtful. The revised groundwater remedy will effectively minimize the spread of contaminants
and DNAPL materials in the soils and groundwater regardless of the amount of infiltration into
-------
20
the contamination zone. Therefore, the need for allowing flushing is minimized, the groundwater
restoration should be relatively unaffected by the amount of infiltration allowed through a cover
system and the design of any cover system should be based on ARARs and what is protective of
human health and the environment given the nature of the material to be covered.
2) Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
This criterion addresses whether or not an alternative will meet all of the ARARs pertaining to
federal and state environmental laws and regulations and/or justifies the invoking of a waiver of
such ARARs. ARARs are considered frozen at the time of remedy selection. However, in
considering ROD amendments, newer pertinent regulations developed since the original remedy
are to be analyzed. The following paragraphs consider ARARS of note since the original ROD.
Comparative Analysis
Air emission treatment requirements, Wisconsin Administrative Code Chapter NR 445, were
considered in the original ROD. A thermal desorption unit is denoted as a miscellaneous
hazardous waste treatment unit under either federal or state hazardous waste management
regulations. With regard to WDNR regulations, such unit is denoted in Chapter NR 670, which
will now be added to appropriate site ARARs. Air emissions from such a unit are regulated
under Chapter NR 665. Of particular note is the instance where the thermal desorption unit
utilizes an afterburner or a flare as a means of controlling volatilized contaminants that have been
driven off the soil mass. In this case, since the soil being put into the unit constitutes a hazardous
waste, then the degree of removal efficiency using a flare must attain 99.99 percent, the same as
would be expected for hazardous waste incineration. Since thermal desorption operates by
driving contaminants off soil, appropriate emission control of soil dusts must be met.
By a combination of treatment and containment, site soils must attain both 1) direct contact
protection levels as established for site users under Chapter NR 720, this value being 3.1 ppm for
direct contact for industrial usage and 1.9 ppm for residential usage, and 2) levels established
pursuant to Chapter NR 720 so that the treated soils will not become a source of groundwater
contamination under NR 140 standards. Since recent groundwater monitoring has indicated
exceedances of three PAH compounds for which PALs have been promulgated under NR 140,
P ALs for naphthalene, fluorene, and benzo(a)pyrene are adopted in this ROD amendment. As
noted previously in this document, these values are respectively 8,80, and 0.02 ppb, respectively.
It is appropriate to do so because of the concept of connection between these PALs and the
groundwater source protection component of the residual contaminant level in NR 720.
U.S. EPA also adjusts the PAL originally set for benzene. At the time of the 1990 ROD, the
PAL value was 0.067 ppb. Since that time, WDNR has now established that a PAL of 0.5 ppb as
protective. In situations where an industrial RCL is to be used, Section NR 720.11(1 )(c), Wis.
Adm. Code, requires that a deed restriction be recorded to prevent future non-industrial land
-------
21
uses. A deed restriction will also be required by U.S. EPA under CERCLA as appropriate
institutional control for adoption of recreational usage and cleanup to such standards for a portion
of the site property.
The asphalt cover over portions of Union Pacific property would not constitute a cover
complying with either federal or state solid or hazardous waste management rules. However,
U.S. EPA is mindful of administrative reforms which seek to promote productive future site
utilization. Provided that this material is not excavated and adequate maintenance/repair of
asphalt paving can be assured, U.S. EPA will not seek further cover of this material. See Figure
9 for the approximate location of this area. Section NR 720.19(2), Wis. Adm. Code, allows a
soil performance standard remedy to be selected in place of a level which complies with an
approved RCL. One such example of compliance would be in arranging for permanent
engineering control, such as defined asphalt inspection and maintenance schedules, to be
established. Should a performance standard for a portion of the site be invoked, a deed
restriction must be recorded to prevent activity that would compromise the performance
standard, such as excavation. A maintenance agreement is required to assure continuing
adequate protectiveness. Section NR 720.19 seems especially pertinent to necessary asphalt
maintenance scheduling and to measures which may be taken to control erosion and undue runoff
which may interfere with subsequent sediment management goals.
Unlike regulations in Chapters NR 720, 670 and 665, Chapter NR 216may not necessarily be
directly applicable to the Moss-American situation. For one thing, Chapter NR 216 concerning
soil erosion/runoff protection measures has a threshold value of 5 acres of construction activity
disturbance, which may or may not occur at the site. For another, Subchapter III is defined in the
"applicability" section as being intended for construction sites with a "point source" discharge of
storm water. Excavation and treatment of "hot spot" areas for thermal desorption may constitute
only sheet runoff if soils are successfully treated. It is appropriate to seek good drainage around
a containment cap, however, and such runoff could be construed as a point source pending its
configuration. Remaining surface soils, particularly on County land, should not serve as future
sources of sediment contamination. Therefore, the control measure concepts within Chapter NR
216 must be followed in site planning efforts.
The Moss-American site is relatively complex, with facets of the remedy addressing various
environmental media. It was presumed at the time of the 1990 ROD and in the Consent Decree
calling for remedial design/construction activity that it might be necessary to handle, stage and
store soils and sediments. For example, predesign task #17 included in the Statement of Work
attached to the Decree notes that "...The staging and storage methods may include open piles
and/or covered piles and enclosed areas..." in managing soils and sediments. It may also have
been presumed that most site remediation work would proceed concurrently, in which case pile
storage of soils or sediments for a lengthy time would not have been a major consideration.
However, U.S. EPA believes it is important to recognize the possibility that site remediation may
-------
ASPHALT
PARKING
AREA
WfTH LIMESTONE
^*Jfe.,..0"AVEI.
GRAVEL
FILL
(LIMESTONE)
FENCE SURROUNDING
CAR STORAGE AREA
SITE BOUNDARY
SCALE IN FEET
FIGURE 9
ASPHALT PAVED PORTION OF
-------
22
proceed in a phased fashion. In that case, excavation done for the purpose of installing hardware
for one phase of site work may be held for a lengthier period of time until other soils (or
sediments) management can be completed. Portions of some highly contaminated soil areas
intended to undergo thermal desorption treatment may require excavation and storage for other
phases of the remedy, such as groundwater management. However, if such stockpile may also be
classified as a hazardous "waste pile" for waste management purposes, then the waste pile needs
to have adequate foundation, leachate control, liner, and wind dispersal safeguards as may be
called for in federal and state regulation. "Waste piles" are addressed in Subpart L of the
hazardous waste section of the federal Resource Conservation and Recovery Act (RCRA), and in
Chapter MR 65 5 of Wisconsin hazardous waste management rules. Federal RCRA regulations,
at 40 C.F.R. § 264.251 (b) allow exemption from certain waste pile design and operating
requirements provided that the pile owner/operator sufficiently justifies an alternate design and
operating practice, and the State waiver provision at Wise. Admin. Code § NR 680.04 can be
exercised accordingly. U.S. EPA believes such justification has been provided in this instance.
In recent correspondence concerning approval of temporary stockpiling procedures, U.S. EPA
and WDNR have indicated that soil treatment capabilities shall be on-line in no more than two
construction seasons from July 1998. U.S. EPA notes that the 1990 ROD indicated that soil,
debris, and sediment undergoing extraction, treatment or redeposition may trigger RCRA
requirements in placement and disposal of such material. In that case, the remedy is expected to
comply with standards contained in the State authorized RCRA program and in the self-
implementing Federal RCRA requirements.
U.S. EPA notes that ch. 636 of the Wisconsin hazardous waste management rules, which justifies
conditions under which a CAMU may be utilized, becomes an ARAR when a CAMU is invoked.
A CAMU is invoked to allow consolidation of contaminated soils from different portions of the
site, as well as the picking up and treatment - and subsequent placement - of contaminated soils
in units with alternative designs. With a CAMU, liners and leachate collection systems are not
required. U.S. EPA and the State have determined that CAMU is appropriate at this Site
provided that the groundwater RCL component is achieved for all the BTEX compounds,
naphthalene, fluorene, and benzo(a)pyrene. Treated sediment may contain other contaminants
that would also need to meet groundwater RCLs or the sediment will have to be managed off-site
or an ESD issued for changing the design of the CAMU disposal unit to include a liner and
leachate collection system.
3) Long-Term Effectiveness and Permanence
This criterion refers to the expected residual risk and the ability of an alternative to maintain
reliable protection of human health and the environment over time, once cleanup objectives have
been met.
-------
23
Comparative Analysis
By invoking concepts of treatment of free-product creosote soil areas, seeking further means of
potential groundwater contaminant control, and seeking erosion protection measures that avoid
future sediment contamination problems, the amended remedy would appear to offer enhanced
long-term effectiveness and permanence in comparison to the original remedy. The original
remedy also did not contemplate the attainment of the groundwater component of the residual
contaminant level. Given the soil contaminants present at the site, the original treatment
technique of bioslurry would appear to have relatively little chance of achieving desired
treatability variance ranges/efficiencies. In comparison, the {thermal desorption technique
appears to have a greater opportunity to achieve not only the desired treatability variance
ranges/efficiencies, but also the pertinent groundwater RCLs. Employment of the thermal
desorption technique so as to attain groundwater RCLs therefore justifies no usage of
liners/leachate collection facilities.
4) Reduction of Toxiciry, Mobility, or Volume through Treatment
This criterion is the anticipated performance of the treatment technologies an alternative may
employ.
Comparative Analysis
Comparison of fiioslurry Treatment with Thermal Desorption:
All alternatives featuring an element of treatment will achieve reductions in toxicity, compared to
approaches which feature only containment or imposition of institutional controls.
The technique of thermal desorption appears to have the potential to yield significantly superior
treatment results compared to that of a bioslurry approach for management of highly
contaminated soils and sediments. As noted, the bioslurry approach should effectively address
that subset of PAHs composed of 2 and 3-ring compounds. Such compounds may comprise the
more mobile PAHs, such as naphthalene. Treatment effectiveness utilizing the bioslurry
technique diminishes with increasing PAH molecular weight. While these heavier compounds
are not relatively mobile, they present toxicity concerns. The literature indicates that the more
complex PAH compounds also tend to be the more carcinogenic compounds. The thermal
desorption process may therefore help to achieve superior results in terms of reducing toxicity in
comparison to a bioslurry approach. Also, by amending the remedy to consider additional
compounds and thereby protecting groundwater from further contaminant sources, the amended
remedy is superior in terms of reduction of contaminant mobility.
-------
24
5) Short-term Effectiveness
This criterion involves the period of time needed to achieve protection and any adverse impacts
on human health and the environment that may be posed during the construction and
implementation period until cleanup objectives are achieved.
Comparative Analysis
Comparison of Bioslurry Treatment with Thermal Desprptio'n:
At the time of development of the original ROD, it was projected that a 15-day retention time in
the bioslurry treatment unit would be necessary for a given batch of contaminated soil or
sediment to attain the desired cleanup goal of 6.1 ppm carcinogenic PAHs. It was noted further
that biological treatment is temperature dependent, and that treatment might not continue through
the winter months. In comparison, the retention time for batch treatment within a thermal
desorption unit would be on the order of hours. Hence the time to learn if effective treatment is
being provided will be reduced. Furthermore, as noted within pilot work conducted on site soils
using the bioslurry approach, it is doubtful that the cleanup goal of 6.1 ppm carcinogenic PAHs
can be attained using the bioslurry approach.
Change in removal cleanup standards based on risk assessment scenarios:
Elsewhere in this document, U.S. EPA has indicated that it believes it is reasonable from an
administrative standpoint to accomplish the obtainment of all necessary deed restrictions within
an expected 180 days timeframe. However, in conjunction with discussion in the ARARs
decision criterion above, it is also important from a technical standpoint that obtaining necessary
deed restrictions be accomplished within the expected 180 days timeframe. As was noted in
ARARs discussion, U.S. EPA's approval concerning temporary stockpiling procedures was
predicated on the basis that it would take no more than two construction seasons from July 1998
to bring soil treatment capabilities on-line. Therefore, U.S. EPA believes it is important to
secure deed restriction in a timely fashion.
6) Implementability
This criterion is the technical and administrative feasibility of an alternative, including the
availability of materials and services needed to implement the given option.
Comparative Analysis
ComDarisom}f Bioslurrv Treatment with Thermal Desorption:
-------
25
In designing a bioslurry approach to soils and sediments treatment, consideration of site-specific
sizing concerns would be an important design component. Materials of construction and site-
specific pumping and valving considerations must be considered. The bioslurry treatment unit
would be, in essence, a permanently constructed site feature. In contrast, thermal desorption
units are not normally built "from scratch." Rather, it is presumed that vendor-developed mobile
equipment would be utilized for thermal desorption remedial action. Remedial design efforts in
implementing such alternative may be less rigorous than for a bioslurry approach. Design for a
thermal desorption unit would focus not so much on what the individual components of a
desorption system are and how they need to be fitted together, but rather on operating
experiences from other pertinent sites, such as removal efficiencies realized and degree of
emission control brought about, as well as necessary verification sample planning. As noted, the
thermal desorption equipment is expected to be a vendor supplied mobile unit. Vendor capacity
and availability are therefore prime considerations regarding implementability. Current
indications are that vendor availability should not pose undue difficulty. Expediency in design of
a soils treatment unit is an important consideration. Final groundwater design management plans
have now been received. Construction of the groundwater funnel and gate in-situ treatment
system is to some degree contingent on progress in remediating those site soil areas associated
with the presence of free-product creosote; Adoption of the thermal desorption approach would
appear to hold an implementability advantage with regard to groundwater treatment progress as
well.
Cover Systems
In discussion of withdrawal of the waiver extended in the previous ROD, and in CAMU
discussion (see pp. 14-15 of this document), U.S. EPA established a "tiered" system of
containment under the CAMU intended to encourage more efficient soil treatment in exchange
for less complex containment measures. Covers range from clay with a frost protection layer to
soil to relatively simple erosion control measures when total attainment is realized of all
groundwater RCLs and pertinent direct contact protection measures. Materials needed for
construction of various cover types are all considered commercially available.
7) Cost
This criterion includes estimated capital costs, as well as operation and maintenance costs.
Comparative Analysis
In comparison to the bioslurry treatment approach estimated to cost about $150-200 per cubic
yard of soil treated, the thermal desorption approach is estimated to cost approximately $75-100
per cubic yard. Additionally, if groundwater RCLs are met then it will not be necessary to add a
-------
26
subsurface synthetic membrane and leachate collection system as a means of containing treated
soil residuals plus lesser areas of contaminated soils. As noted in the discussion of
Implementability above, ultimate cost of appropriate containment measures is dependent on the
degree of efficiency realized in thermal desorption.
8) State Acceptance
This criterion indicates aspects of the recommended alternative and other alternatives to which
the state support agency (WDNR) favors or objects, and comments regarding state ARARs or the
proposed use of waivers. While WDNR indicated general agreement with the broad concepts
noted in the proposed plan - usage of thermal desorption and consideration of industrial or
recreational usage scenarios - WDNR did not concur with the proposed plan issued by U.S. EPA
which solicited public comment concerning the potential ROD amendment. WDNR requested a
30 day extension of the public comment period. U.S. EPA did in fact extend the public comment
period. Within the Responsiveness Summary, U.S. EPA believes it has satisfactorily provided a
reply to WDNR concerns. U.S. EPA has included certain details in the ROD amendment not
included in the proposed plan so as to indicate its intention of conducting the remedy in
accordance with pertinent ARARS. The State of Wisconsin has indicated it will provide
conditional concurrence with this Record of Decision Amendment. The State of Wisconsin's
letter indicating this position will be included in the Administrative Record for the site.
9) Community Acceptance
This criterion indicates the public support of a given alternative. This criterion is discussed in
the Responsiveness Summary. Numerous oral and written comments were received at the March
18,1998 public meeting. Written comments were also received both before and after the
meeting. The majority of comments indicated that U.S. EPA should adopt the changes discussed
in this amendment. Union Pacific appears to favor usage of an industrial usage scenario to guide
cleanup on its property. Milwaukee County does not appear to favor at this time any change in
exposure scenario with regard to its property. There will be opportunity for discussion between
the property owners and KMC to determine what deed restrictions can be developed concerning
respective property.
Statutory Determinations
The amended remedy complies with the requirements of CERCLA Section 121 by considering
and controlling site risks associated with direct contact with soil contaminants, and has beneficial
-------
27
impact with regard to associated contaminated groundwater and sediment measures. The action
will not cause unacceptable short-term risk or cross-media impacts. There are no chemical,
action or location-specific ARARs identified for this action that were not previously considered
in the administrative record. The amended remedy is cost effective. The amended remedy also
considers Superfund administrative reforms and presumptive remedy information not available at
the time of the original ROD. The amended remedy should also significantly reduce treatment
costs compared to the original means of soils treatment specified.
The 1990 ROD justified a waiver pursuant to Section 121(dX4)(B) for a Subtitle C cap and for
the State double-liner/leachate collection system requirement on the basis that an impermeable
cap and liner would pose a greater risk to health and the environment by prolonging groundwater
treatment and time needed to achieve groundwater goals. Given change in the groundwater
remedy under the 1997 BSD, waiver of a relatively impermeable cap is no longer justified.
However, in making usage of alternative reconsolidation unit designs, U.S. EPA invokes the
CAMU concept. U.S. EPA notes that ch. 636 of the Wisconsin hazardous waste management
rules, which justifies conditions under which a CAMU may be utilized, is a means of meeting
this ARAR. A CAMU is invoked to allow consolidation of contaminated soils from different
portions of the site, as well as the picking up and treatment - and subsequent placement - of
contaminated soils in units with alternative designs. With a CAMU, liners and leachate
collection systems are not required. Pursuant to ch. 636, the condition which should exist such
that an unacceptable risk is not created is attainment of pertinent RCLs prior to containment
efforts.
The amended remedy provides the best balance of tradeoffs with respect to the evaluation
criteria. The amended remedy satisfies the preference for treatment as a principal element of the
remedy.
Documentation of Significant Changes
The Proposed Plan for consideration of substitution of thermal desorption technology, allowance
for adoption of industrial or recreational exposure scenarios, and difference in relatively
permeable versus non-permeable capping materials at the Moss-American site was issued for
public comment on March 9, 1998. The Proposed Plan identified Alternative 2 - usage of
thermal desorption technology, adoption of industrial or recreational exposure scenarios, usage
of impermeable capping materials - as the recommended alternative. U.S. EPA has reviewed all
written and verbal comments submitted during the public comment period. Upon review of these
comments, it was determined that no significant changes to the remedy, as originally identified in
the Proposed Plan, were necessary.
-------
Responsiveness Summary
Moss-American Site
Milwaukee, Wisconsin
This Responsiveness Summary has been prepared to meet the requirements of Sections 113(k)(2)
(B)(iv) and 117(b) of the Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of
1986 (SARA), which requires the United States Environmental Protection Agency (U.S. EPA) to
respond to "...to each of the significant comments, criticisms, and new data submitted in written
or oral presentations" on a proposed plan for remedial action. The Responsiveness Summary
addresses concerns expressed by the public, potentially responsible parties (PRPs), and
governmental bodies in the comments received by U.S. EPA regarding the proposed plan for
remedial action at the Moss-American site. '
Background on Community Involvement
Following signature and issuance of the September 1990 Record of Decision (ROD) concerning
the site, U.S. EPA prepared and released to the public a series of fact sheets regarding site
developments and progress. These fact sheets have been developed approximately semi-
annually. In April 1997, U.S. EPA issued an Explanation of Significant Differences (ESD) with
regard to how groundwater management strategy was to be conducted at the site. Concurrence
was obtained on this document from the Wisconsin Department of Natural Resources (WDNR).
The ESD allowed the Settling Defendant (Kerr-McGee Chemical LLC, or KMC) to develop an
innovative funnel and gate collection and treatment approach. The ESD and an accompanying
fact sheet were released to the public.
Beginning on March 9,1998 U.S. EPA initiated a public comment period concerning a proposed
plan which suggested amendment of the 1990 ROD hi two important areas. These are: whether
to adopt non-residential exposure scenarios to guide the degree of contaminated soils cleanup,
and whether to adopt the treatment technique of thermal desorption as a means of treating more
highly contaminated soil areas, rather than use the bioslurry treatment approach originally
selected. The comment period lasted until May 8,1998, after U.S. EPA extended the initial 30-
day comment period by an additional 30 days in response to a request received from the WDNR.
On March 18,1998 U.S. EPA conducted a public meeting at Vincent High School in Milwaukee
to discuss the proposed plan concerning the ROD amendment. Also during this meeting, oral
comments were received.
-------
Comment on the Proposed Plan for the ROD Amendment
Written Comment:
from the Wisconsin Department of Natural Resources - dated March 11, 1998
This letter provides our comments on the above-referenced document. As you know, we
provided comments on drafts of the PP Fact Sheet that were not addressed in the final document.
Hence, our concurrence with the PP is being withheld (the PP correctly states this). Most of our
previously unaddressed comments are provided here again.
There are several important topics we expect you will address in a subsequent ROD amendment
that are unclear, improperly presented or not presented at all in this fact sheet. Therefore, we
suggest that you issue a revised PP or corrections/revisions to the fact sheet document before the
public meeting and, if necessary, extend the PP comment period appropriately. If you do, we
would likely be willing to provide our concurrence with the PP proposal.
Response - Given the timing of the receipt of this letter in connection with the scheduled
date for the public meeting, it was not possible to issue a new or revised fact sheet.
We suggest that the issuance of any subsequent ROD amendment be withheld until an agreement
is reached between the Agencies and Kerr-McGee on revisions to the existing Consent Decree
(CD) for the remedy revision contemplated under this PP, or the ROD state that it would not be
effective until that occurs. This will avoid the possibility of having a final, effective ROD in
place that conflicts with the existing CD.
Response - U.S. EPA strongly believes the focus should be on the selection of the remedy.
Section 113(j)(2) of CERCLA, 42 U.S.C. § 9613(j)(2), provides that the courts shall uphold
the response action selection decisions unless the objecting party can demonstrate on the
administrative record, that decision was arbitrary and capricious or otherwise not in
accordance with law. Section 113 and Section 117 also discuss public participation
procedures concerning remedial action once the administrative record is established.
These procedures provide that U.S. EPA is to base selection of remedial action on the
record after providing for notice to the public and a brief analysis of alternatives
considered, reasonable opportunity to comment and provide information regarding the
plan to the public, provide opportunity for a public meeting, respond to each significant
comment or new data submitted, and provide a statement for the basis and purpose of the
selected action.
-------
If U.S. EPA fails to sign any ROD amendment which may prove warranted pending
comment receipt and evaluation, and the Court is then approached to modify the Decree,
the basis for Decree modification would seem incomplete. Opportunity to conduct site
remediation would be hindered. This comment also would appear to involve a larger
discussion than the Moss-American Site. If U.S. EPA were to adopt the point of view
advocated, it would find it necessary to approach the Court before proposing modifications
where the Agency had entered a Decree. Until the ROD Amendment is signed, there is no
decision by the Agency to change the remedy. Moreover, proceeding with the Consent
Decree modification before issuance of the ROD would undercut public participation in the
ROD amendment process. Before U.S. EPA would seek to amend the decree concerning
the direction of significant site work, U.S. EPA would have to reach a decision as to how to
amend the remedy pursuant to the process and delegation of CERCLA, including the
public participation process. <
It should also be noted that the actual Consent Decree modification entailed by this ROD
Amendment would be limited. The current Consent Decree already contemplates a change
in the treatment technology, after a ROD amendment, if the bioslurry reactor cannot
achieve cleanup standards. Risk assessment scenarios and discussions on how to attain
new or existing requirements are a means at arriving at the remedy decision and, while
part of the record, would not be discussed in the Consent Decree. It is the resulting
cleanup standards and cover specifications which would be addressed in the Consent
Decree. The changes to these involved in this ROD amendment are limited.
We are in general agreement with the concepts of changing the direct contact route soil exposure
scenario assumptions to be consistent with ch. NR 720, Wis. Adm. Code, and the substitution of
low temperature thermal desorption (LTTD) for slurry bioremediation treatment, provided our
concerns are addressed.
Specific comments:
1. Second U, third sentence, states: "Those contaminated sediment areas where sediment is
removed by dredging techniques near bridges or are particularly highly contaminated may also
undergo thermal desorption treatment." We are unsure what the intent of this statement is, so it
should be clarified. What does "highly contaminated" mean? We believe your intent is to state
that the PP preferred alternative is to treat, using low temperature thermal desorption (LTTD),
sediments removed from the old channel of the Little Menomonee River (LMR) after a new
channel is constructed, per the original 1990 ROD. If so, the PP should have stated that, and
gone on to indicate that those sediments and include all visibly contaminated sediments and
sediments with a CPAH content above 388 mg/kg in the old channel and all sediments located
where the new channel crosses the old, such as bridge crossings.
Response - The current ROD and the Statement of Work accompanying the remedial
-------
design/action Consent Decree both recognize that some portion of contaminated sediments
may be subject to treatment efforts, rather than containment. Hence, if U.S. EPA proposes
in the plan that thermal desorption be substituted for bioslurry treatment, then it should
note all current instances where such treatment would be expected. On page 9 of the
Statement of Work, it is noted that "...in the portions of the channel of the Little
Menomonee River which are not rechannelled, e.g., under bridges, Settling Defendant shall
remove sediment...in excess of the sediment quality criteria or sediment background...treat
sediment in excess of 6.1 ppm CPAHs using the treatment system...** If any further
amendments were considered involving sediment management, this concept could be
changed. However, for now, U.S. EPA feels the plan should note that some treatment of
sediments is expected and that any modified treatment method should consider this point.
2. Figure 1 is very confusing. What is the purpose of this figure? Is it a site map, as the title
states, or a representation of a portion of the preferred plan? Why are areas going to be covered
with asphalt or soil? That covering activity is not described in the PP. What is the difference
between BTEX areas and other areas? What do BTEX areas represent?
Response - Figure 1 was intended to show the reader/commenter that some areas of the site
are intended to undergo excavation and treatment for different reasons. The original ROD
basically wanted areas to undergo treatment solely because of perceived excessive CPAH
content. In this plan, there could be one of three reasons why a given contaminated soil
area should undergo treatment: it has excessive CPAH concentration such that toxicity is a
problem (the Agency's working definition of "hotspot"), it has excessive free-product
creosote below the ground's surface which must be addressed to aid in managing site
groundwater, or it has certain more mobile contaminants - the volatile
benzene/toluene/ethyl benzene/xylene (BTEX) compounds - which need to be controlled so
that they will not pose a problem as a groundwater contamination source under State rules.
Other areas indicated for further cover are to show that there may be excavation and
consolidation of other soils not requiring treatment. "Soil" describes the current means of
cover, which as the plan notes is also subject to change to a more rigorous form. The term
"asphalt" is archaic; however were the topic to come up we could inform the public that at
one point in time the Decree signatory parties had discussed asphalt usage when
extractable quantities of free-product creosote were first made obvious. However, the
relatively fine nature of the soils and the limited amount of free-product creosote made that
concept impracticable.
3. Figure 2 only shows the "condenser" type operation and so the figure should be labeled as
such, e.g., "Figure 2 Thermal Treatment with Condenser Sorption Unit (Afterburner not shown)".
Response - The drawing in question was taken directly from a U.S. EPA paper on the topic
of thermal desorption. The drawing in that paper made no specific reference to emission
control system in its caption; hence U.S. EPA did not feel that was necessary for this plan.
However, in the text which refers the reader to Figure 2, the three main types of emission
-------
control are noted.
4. Page 3, second U, fifth sentence, states: "This process would be regulated by Wisconsin state
air emission and hazardous waste standards for "miscellaneous treatment units." This sentence is
misleading, as the reader may get the impression that both our Air Management and Hazardous
Waste Programs would regulate the unit only as a "miscellaneous treatment unit", which is
incorrect. The Air Management Program would regulate it as an emission source subject to their
emission limits. The Hazardous Waste Program would regulate the thermal desorption portion
of the unit as a "miscellaneous treatment unit", but would regulate an afterburner as a hazardous
waste incinerator.
Response - Having received unofficial comment from other persons regarding plan
contents which noted that the text was becoming complex, enough, U.S. EPA did not feel it
necessary to insert this level of detail. The plan does refer the reader to the administrative
record for additional information. Further discussion of this point is noted in the ROD
amendment
5. Page 2, fourth and fifth fs: It is stated in both YS that the original soil cleanup goal for the site
is 0.061 ppm CPAHs. This is incorrect, as this goal only applied to a portion of the site under
the 1990 ROD, e.g., soils in the floodplain at the wood treating property and the Northeast
Landfill. The cleanup goal for other soils, including soils on the wood treating site outside of the
floodplain and soils in the floodplain downstream from the wood treating property under the
original 1990 ROD is 6.1 mg/kg (ppm) CPAHs. It should be noted that soils in the floodplain
downstream of the wood treating property are not addressed in this PP.
Response - Table 3 of the current ROD states that 6.1 ppm CPAH represents a 10-4 risk
level. In describing the cover system to be used for Alternative 3A, the selected alternative,
page 21 of the ROD states in part: "...treatment residue from the slurry bioreactor, and on-
site contaminated soil exceeding the 1 x 10-6 target concentrations, a total of 210,000 cubic
yards, will be contained in the Area of Contamination (AOC), covered with 2' of clean soil
and 6" of topsoil..." This text makes no distinction as to "only" floodplain soils, and indeed
could be interpreted to mean all site soils above 6.1/100, or 0.061 ppm CPAHs, are to be
contained. In any event, given the new state of knowledge of background PAH levels in
urban areas, 0.061 ppm CPAH is not a realistic goal and should be changed.
6. The PP does not describe our ch. NR 720, Wis. Adm. Code, soil standards for protection of the
groundwater (groundwater soil remedial contaminant goals, or RCLs) and how they would be
achieved. This is a significant omission. In place soils that exceed groundwater RCLs for all
contaminants of concern must be addressed directly or through a performance standard (we
understand that Kerr-McGee's last proposal to the Agencies on this was to directly address these
soils), and all treated soils that are returned to the site for redisposal must meet those RCLs if
replaced in an unlined unit.
-------
Response - U.S. EPA disagrees. The plan notes (page 3) that cleanup goals will be
developed to attain Wisconsin state soil cleanup standards. Since those standards include a
groundwater component, such groundwater protection is inferred. Again on page 4, the
plan notes that cleanup standards are to attain direct contact and ground-water protection.
U.S. EPA discusses this point further regarding oral comments made on this subject.
7. The PP should indicate that the preferred alternative includes removal of highly contaminated
soils from below the water table.
Response - Figure 1 indicates that some soil areas are to be excavated and treated because
they are associated with potential free-product in the subsurface soils. Some means of
verification sampling will need to take place to know if sufficient quantity of soil
management has occurred. U.S. EPA cannot say what the verification sampling will
indicate; hence it cannot stipulate that excavation will occur below the water table.
However, U.S. EPA believes that the signatory parties to the RD/RA Decree are agreed in
principle that should there be obvious indication of free-product material extending below
the water table that this will be pursued to the degree possible.
8. The PP does not adequately describe how our ch. NR 720, Wis. Adm. Code, RCLs for direct
contact would be achieved. Again, soils exceeding direct contact RCLs for all contaminants of
concern must be addressed directly or through a performance standard. We understand that Kerf-
McGee's last proposal to the Agencies was to address any in place soil that is not treated through
a performance standard cover of soil or asphalt. The soil and asphalt cover areas mentioned in
figure 1 are without any context or proper details. The mention of a "less-extensive containment
system for...less contaminated soils" in the description of Alternative 2 may refer to this, but this
is unclear. The general design of the performance standard cover systems proposed should be
provided, preferably with figures showing the design of the elements and their location.
To allow a performance standard remedy under ch. NR 700, Wis. Adm. Code, appropriate deed
restrictions and adequate maintenance assurances/agreements are required. The maintenance
assurances/agreements are not mentioned in the PP.
Response - The Settling Defendant performed multiple sets of calculations to indicate that a
direct contact cleanup level of 3.1 ppm CPAH would be the appropriate value if an
industrial exposure scenario were adopted. This is noted on page 4 of the plan. The value
of 49 ppm CPAH is also noted, in case a recreational exposure scenario is adopted. At the
public meeting, U.S. EPA discussed different cross-section cover descriptions, for which
WDNR assisted with preparation of unit dimensions. However, U.S. EPA did not put such
cross sections in the plan since, as noted earlier, having received comment from other
persons regarding plan contents which noted that the text was becoming complex enough,
U.S. EPA did not feel it necessary to insert this level of detail. This matter is also discussed
in the ROD amendment. Upon review of recently received groundwater monitoring
results, U.S. EPA does note that while many monitoring wells at the site are relatively free
-------
of contamination, three wells (MW-4S, MW-7S, and TW-09) standout in terms of
naphthalene content in the part per million range whereas the protective action limit (PAL)
is in terms of parts per billion. Other excesses at these wells also occurred for fluorene and
benzo(a)pyrene. These three compounds are promulgated under NR140. Hence, in the
ROD amendment, U.S. EPA does adopt the RCLs for groundwater protection pertinent to
these three compounds, and cites area* shown from the Remedial Investigation to be above
the groundwater RCL for these compounds as requiring verification and/or soils treatment
before containment steps are undertaken.
9. The PP should indicate that the free product recovery system would be shut down and
removed from the site when the preferred alternative is implemented.
Response - U.S. EPA does not believe the plan needs to state this. U.S. EPA wrote the
Proposed Plan so that the general public plan reader would concentrate on the big picture
and direct comment to the main issues of "shall thermal desorption substitute for bioslurry
treatment, and is it appropriate to consider non-residential exposure scenario(s) for
portions of the site"? Subsequent developments in groundwater design and temporary
stockpile concepts indicate that there may be a phasing of work regarding both
groundwater management and soils remediation. Hence, there may need to be flexibility in
shutting down the free product recovery system as welL
10. The PP does not adequately describe the redisposal unit for LTTD treated soil and sediment.
All that is stated is that a "less-extensive containment system would be needed for soil
residuals..." in the description of Alternative 2. It is unclear what "soil residuals" are. The
general design of this unit, including its cover, should be provided, preferably with figures
showing the design of the unit and its location.
Response - Again, U.S. EPA believed it was best to write the plan such that the general
public plan reader would concentrate on the big picture and direct comment to the main
issues of "shall thermal desorption substitute for bioslurry treatment, and is it appropriate
to consider non-residential exposure scenario(s) for portions of the site"? Soil residuals are
those soils which have undergone treatment. U.S. EPA sees two primary options: a,)
Following treatment, the soil attains all direct contact, ground-water protection, and
surface runoff protection goals. At that point, the soil has basically dropped out of the
system, and could be returned to its place of origin needing only simple erosion control
measures, b.) The soil shows marked improvement in terms of contaminant content, but
does not attain "walk-away" goals. In that case, the soil is consolidated with other
materials needing cover using compacted clay with the soil-frost protection layer.
U.S. EPA adds, in the ROD amendment, that the question of attainment of appropriate
concentration range or reduction efficiency, as well as pertinent groundwater RCLs also
arises. Full attainment of these conditions, and employment of a Corrective Action
Management Unit (CAMU) concept would allow utilization of a cover only. If such
conditions cannot be met, then liner usage may also be necessary. Both U.S. EPA and
-------
8
WDNR expect that thermal desorption treatment can attain pertinent removal efficiencies
and RCLs.
11. The untreated soil and sediment that are planned to be treated contain a listed hazardous
waste. We have recently learned that treated soil and sediment may have to meet hazardous
waste land disposal restriction (LDR) standards before redisposal on the site. The LDRs may be
more stringent than the groundwater RCLs. This requirement, or a justified proposal for an LDR
treatability variance, should be discussed in the PP. We are willing to work with our Hazardous
Waste Program, and, if necessary, your RCRA Program contacts to resolve this issue.
Response - If any more stringent level of treatment is required, then that would seem to be
reason to adopt Alternative 2 in the plan, since it may be capable of achieving greater
removal efficiency. The 1990 ROD already lists Table 3, which provides an account of
"Treatment Levels to be Obtained to Comply with LDR Treatability Variance". It appears
that direction is to achieve the LDR treatability variance or the RCL, whichever is the
lesser value. U.S. EPA will review Table 3, and update this as necessary to reflect current
reduction efficiencies for types of compounds, desired concentration ranges, and threshold
values. U.S. EPA is listing in the ROD amendment the pertinent RCLs for groundwater
for the compounds benzene, xylene(s), ethylbenzene, toluene, naphthalene, fluorene, and
benzo(a)pyrene. However, the direct contact pathway, as opposed to probability of aquifer
usage, appears to be of more day-to-day concern for the average site user.
12. The note on the bottom of page 4 describes a proposal for a CERCLA equivalent standard of
performance waiver for, presumably, the LTTD treated redisposal unit. In order to grant such a
waiver, there must be a basis for doing so. We are not aware of any information developed by
the agencies or by Kerr-McGee to justify such a waiver. Our opinion is an unlined unit, even for
soils treated to meet appropriate RCLs (and LDRs, as necessary) would not perform in an
equivalent way to a lined unit, because it may be possible for some contaminants to leak out of
the waste. However, there may be a basis for allowing an unlined unit (e.g., not meet the RCRA
minimum technology requirements or MTRs) under our CAMU authority, ch. NR 636, Wis.
Adm. Code, or an exemption under s. NR 680.04, Wis. Adm. Code, if it can be shown that the
unlined unit would be as protective as a lined unit. Again, there would need to be basis for using
CAMU or granting such a waiver. We would normally expect the persons who propose the unit
to provide such justification. For this site, we would expect Kerr-McGee to provide it.
Response - In making a pro-active determination to waive an ARAR, U.S. EPA is limited to
six situations. Clearly, equivalent standard of performance is the most applicable
justification in this instance. The main point is to describe for the general public plan
reader why the original choice of a permeable cap is no longer valid, and if that is the case,
what replaces it. Moreover, U.S. EPA disagrees with WDNR's contention that there is no
basis to justify a waiver, or that soils in this situation will present a leachate problem if they
attain RCLs. In considering the matter of whether an unlined unit might yield an
equivalent standard of performance for this site, U.S. EPA makes note of NR 720.1 l(2)(b)
-------
and the note which follows which says: "...For example, at a site where soils are
contaminated with diesel fuel, polynuclear aromatic hydrocarbons (PAH) compounds are
present and may be considered contaminants of concern. With the exception of
naphthalene, PAH compounds are generally only of concern for direct contact due to their
relatively low migration potential..." The materials used at the site consisted of creosote
and fuel oil. Hence, U.S. EPA believes this passage in NR 720 is pertinent to the site
situation. Naphthalene is not one of the primary CPAHs. Rather, it is a 2-ring member -
PAH compound having a lower boiling point than the more complex CPAH compounds. If
the more complex CPAH compounds are treated efficiently, then soil napthalene should
undergo at least as high if not higher level of removal efficiency. As is explained in the
ROD amendment, U.S. EPA does endorse CAMU utilization for this site as may be allowed
both under federal regulation and NR 636. An important concept within NR 636 is that
such CAMU inclusion will enhance implementation of effective, protective and reliable
remedial actions for the facility. Utilizing the CAMU encourages treatment of
contaminated soil areas. Utilizing the flexibility within CAMU in managing remediation
wastes, U.S. EPA can then offer a "tiered" approach to subsequent containment methods,
such that a higher degree of removal efficiency realized may result in less rigorous
containment efforts. Without utilizing the CAMU concept, difficulty would be encountered
in managing soils at the Moss-American site since there are several subareas requiring
excavation, treatment, or other consolidation. The act of "placing" treated residuals might
also trigger the need under the Resource and Conservation and Recovery Act to utilize
minimum technology requirements in containing hazardous waste regardless of removal
efficiency realized. Usage of the CAMU appears to allow for greater flexibility in
materials management while still providing for protectiveness.
from R. Zachow - Milwaukee - received March 16,1998
I feel that Alternative 2 is the procedure to follow based on the Figure 3 evaluation table. I
would find it very hard to understand why proceeding with the clean up should be delayed for
more than one year. I have lived along the Little Menomonee River [Pkvvy] for more than 20
years, and my children 20 years ago received burns from the contaminants and [till] this date I
still can not see aquatic life existing in this section of the river. Fix it.
Response - U.S. EPA notes that Alternative 2 calls for site management using low-
temperature thermal desoprtion (LTTD), adoption of an industrial-use scenario for Union
Pacific owned site land, and adoption of a recreational-use scenario for Milwaukee County
owned land. U.S. EPA concurs with the comment that Alternative 2 is the procedure to
follow. U.S. EPA notes that final groundwater management design plans have been
received. In approving supplementary temporary stockpiling concepts, U.S. EPA believes
it is appropriate to strive for opportunity to conduct phases of the remedy as soon as
possible. U.S. EPA sees no hindrance to the implementation of certain necessary
-------
10
groundwater management steps. In its approval conditions, both U.S. EPA and WDNR
have indicated their desire to see on-line soil treatment capability in no more than two
construction seasons, and preferably by next spring's construction season. U.S. EPA
shares the commenter's concern about contaminated sediment management. As noted in
the proposed plan, should natural resource trustee discussions result in recommendations
to alter current sediment management features of the cleanup, U.S. EPA will develop
another proposed plan.
from R. Vesely - Milwaukee - received March 16,1998
I suggest Alternative 2. My house is on the Little Menomonee River. Being down river about 5
or 6 miles I would like to know more about the river bed sediment clean up. You did not state
how far down by locality. I'm between Silver Spring Drive and Hampton Ave. Did the big
flood last spring spread these contaminants?
Response - U.S. EPA concurs with the comment that Alternative 2 is the procedure to
follow. As noted in the proposed plan, should natural resource trustee discussions result in
recommendations to alter current sediment management features of the cleanup, U.S. EPA
will develop another proposed plan. The commenter lives next to what has been termed
segment 5 of the Little Menomonee River, as noted in Figure 6 of the 1990 ROD. Since
WDNR has recommended - and U.S. EPA concurs with - an overall sediment cleanup value
of 15 ppm CPAH (which accounts for background conditions in an urban stream setting),
it would appear that remedial action is warranted in the vicinity of the commenter's
location. Figure 6 indicates that remedial investigation sampling points 1 and 6 both
exceed the 15 ppm CPAH cleanup recommendation, U.S. EPA presumes that the
commenter is referring to a rainfall of approximately 5 inches that occurred in the
Milwaukee area in June 1997. It is possible that a storm of this magnitude could have
caused a shift in location of contaminated sediments.
from R. Salcedo, PhD. - Milwaukee - received March 16, 1998
1. What is the "most nasty" PAH constituent in the soil that will be treated with a low-
temperature desorption unit?
Response - U.S. EPA believes that benzo(a)pyrene, would likely be the most carcinogenic of
the CPAHs identified on the site.
2. Any metals in the soil that will be part of the "treatment mix"?
Response - No doubt commonly occurring metals as would be found in soils would occur.
However, metals as hazardous substances were not identified as contaminants of concern at
the site.
-------
11
3. At what temperature (minimum/maximum) range, and residence time will the unit operate?
Response - According to the literature, the Pacific Place site realized excellent CPAH
removal efficiency at 900 deg. F at a residence time of 85 minutes. This would likely be the
maximum range. It is possible that such operating conditions could be reduced when
dealing with a soil area having predominantly more volatile BTEX compounds.
4. Will there be post-treatment sampling/analysis of the soil before being put back into the site?
Response - Yes, U.S. EPA would expect such sampling/analysis to be part of standard
operating practice.
5. Any air sampling and analysis to be done before release into the environment?
Response - Yes, U.S. EPA would expect such sampling/analysis to be part of standard
operating practice.
6. How does this treatment method complement the "funnel and gates" system, especially with
the inclusion of some sediments?
Response - U.S. EPA would foresee that contaminated soils would be managed first, with
sediments awaiting natural resource trustee developments/recommendations. Thermal
desorption should strongly complement funnel and gate groundwater management.
Certain soil areas believed to be contaminated with free-product creosote need to be
addressed before groundwater management efforts could be expected to be efficient.
7. What are the expected residuals of the treatment (recommended), relative to the original input?
Response - Again, with regard to the Pacific Place site, removal efficiencies of 99.9% were
realized. Information submitted by the Settling Defendant, KMC, in this matter, indicated
removal efficiencies of 95-98% utilizing the thermal desorption technology.
8. Is this same technology (low-temperature thermal desorption) also applicable for treating
contaminated sediments in our local rivers...and the Milwaukee Harbor estuary and Lake
Michigan?
Response - U.S. EPA notes that the technique was used successfully at the Waukegon (IL)
harbor situation involving high levels (>500 ppm) of PCS contaminated sediments. Less
contaminated sediments were contained. Whether or not the technique could be
successfully used at other Milwaukee area river/harbor areas would depend on the nature
of the contaminants of concern for those areas. The technique would appear to be best
suited for situations involving organic contaminants not cross-contaminated with dioxins.
Logistics involving the length of the area or time needed to accomplish dredging might also
-------
12
be a factor.
from A.FC. Watson - Kerr-McGee Chemical LLC - March 17, 1998
I am writing regarding the fact sheet "Proposed Plan - Moss American Supertund Site"... dated
March 1998. In this document, ...U.S. EPA has proposed several changes to the Record of
Decision for the ...site. We at Kerr-McGee Chemical LLC have reviewed your proposal and -
believe it to be a significant step in the right direction. We support remedy changes along
general lines of your proposal. If we have any questions or comments, I will submit these to you
during the 30-day comment period.
Response - U.S. EPA concurs with the comment.
f
from J. Brengosz - Milwaukee - submitted at the public meeting - March 18,1998
! endorse the use of Alternate #2 amended ROD for the Moss American site, and would
encourage prompt approval by the government agencies involved so that remediation can
proceed as soon as possible.
Response - U.S. EPA concurs with the comment
from S. Brengosz - Milwaukee - submitted at the public meeting - March 18,1998
With the lower cost of desorption can we (Kerr-McGee) afford to treat more soil with the funds
available.
Response - That is possible, although the need to perform additional excavation and
treatment will be dependent on verification sampling results.
Is the 15 ppm in river sediment a safe level for the intense use it can receive with children, pets,
etc.
Response - In correspondence dated March 4,1998 WDNR informed U.S. EPA that "...we
subsequently accept the 15 rag/kg [ppm] value as the river-wide maximum probable
background (MPB) value to drive sediment and bank soil cleanup in all segments of the
Little Menomonee River (LMR). The main reason we accept it is that it appears to be a
reasonable value and consistent with the tributary-specific and upstream reach sampling of
the LMR..," Hence, U.S. EPA believes the value to represent a safe cleanup level.
I agree with WDNR that some floodplain soil sampling should be done to determine if any
movement of sediments with recent flood events has occurred.
Response - The proposed plan under consideration deals primarily with means of soils
-------
13
treatment and possible adoption of non-residential exposure scenarios. Discussions among
natural resource trustees are on going concerning issues more closely related to sediments
management. Pending resolution of such discussions, as noted in the proposed plan, U.S.
EPA would be prepared to discuss sediment management issues further in a subsequent
proposed plan if such development is warranted.
Seems to me erosion control should be used no matter what size - you mention 5 acres -
construction is done.
Response - Erosion control planning and control measures are discussed in WDNR
Chapter NR 216, Subchapter III. NR 216.42 discusses applicability. It notes "...Except as
provided in subs. (2) to (4), a notice of intent shall be filed by any landowner who intends to
create a point source discharge of storm water associated with a construction site activity to
the waters of the state...** The definition of "construction site" given in NR 216.002 notes
"construction site" means "...a site upon which land disturbing activities affecting 5 or
more acres of land are occurring..." This same section of definitions later defines "point
source** as meaning "...a discernible, confined and discrete conveyance of storm water...**
Hence, U.S. EPA believes there are clear limitations put on rule applications.
I agree with all the WDNR comments.
Response - Please refer to U.S. EPA's specific responses to WDNR comments provided
elsewhere in this document.
Feasibility seems to be very good for desorption and this is something I would support.
Response - U.S. EPA concurs with the comment.
Realistically, residential use will probably never happen @ this site, but recreational use will
always occur.
Response - U.S. EPA concurs with the comment.
from the Wisconsin Department of Natural Resources - dated March 31, 1998
This letter provides additional comments on the above-referenced document, supplementing our
previous comments. We request that the PP be amended to account for a hazardous waste pile
storage unit at the site for soil and debris excavated for the groundwater remedy. This unit was
proposed for the first time in the final groundwater design, which we received on March 11,
1998. We believe this type of longer term hazardous waste pile storage unit was not envisioned
in the current ROD and Consent Decree.
-------
14
Response - U.S. EPA incorporates the April 14,1998 response signed by the site's
Community Involvement Coordinator into the Responsiveness Summary as the primary
vehicle providing response to the March 31,1998 WDNR comments. U.S. EPA provides
other details as stated further. The 1990 ROD notes on page 40 that "...Waste on the site is
listed under RCRA as Hazardous Waste, K001 and U051..." The 1990 ROD continues on
page 41 "...Because soil, debris, and sediment containing listed hazardous waste will be
extracted, treated and redeposited... placement and disposal will occur triggering RCRA -
requirements... The selected remedy will comply with standards contained in the State
authorized RCRA program and in the self-implementing Federal requirements...**
Attached to, and made part of the Consent Decree, is a Statement of Work listing
numerous predesign tasks to be accomplished. Two of these are predesign tasks #17 and
18, which discuss respectively "Define Handling, Staging, and Storage Systems for Soil and
Sediments" and "Define Handling, Staging, Storage and Placement Systems for Treated
Soils and Sediments". Predesign Task #17 says in part "...The staging and storage methods
may include open piles and/or covered piles and enclosed areas..." Predesign Task #18 says
in part "...Storage methods may include open piles, covered piles, or enclosed areas..." In
describing remedy components for features other than groundwater control, the ROD, in
discussing Alternative 3A, the alternative selected, notes that time to implement would take
3-4 years.
As noted in the Proposed Plan, a 15-day treatment period is anticipated per batch of
soil/sediment treated via the bioslurry approach. Several tens of thousands of cubic yards
of soils/sediments were to be treated in this fashion. Since creosote is a listed hazardous
waste for RCRA purposes, those areas of soils/sediments posing greater than acceptable
user or environmental risks would be considered hazardous waste piles if excavated and
subsequently placed. U.S. EPA notes that in its judgement, it is more likely to expect the
Settling Defendant to accomplish as much excavation as possible via a given contractor,
and to place excess materials in some manner of storage until they can be worked off,
rather than calling upon an excavation contractor to re-visit the site every couple of weeks.
U.S. EPA notes that the existence of these clauses in Predesign Tasks # 17 and 18 was
pointed out by the assigned Remedial Project Manager in correspondence with the WDNR
Project Manager, and that such clauses were acknowledged by WDNR.
What the existing ROD and' Consent Decree may have presumed was that all remediation
work would be done concurrently. However, the Moss-American site is relatively complex
with several different facets of work. It may be prudent to have a given piece of work
conducted ahead of others. In essence, that is what the Settling Defendant was suggesting
in a portion of the groundwater design; that groundwater construction could move ahead
of soils remediation and sediment management. Of course, any such stockpiling must be
managed in a sufficiently protective fashion.
On April 22,1998 representatives of U.S. EPA, WDNR, KMCC and their consultant
engaged in a conference call to explore what options there may be to minimize soil
-------
15
excavation necessary to accomplish groundwater treatment system installation, and options
concerning soil stockpile management that would result in acceptable protection. On July
27,1998, U.S. EPA, with input from WDNR, was able to indicate approval of stockpile
management concepts from KMCC provided - among other things - that the parties
understood such stockpiling was to be of a temporary nature with the ability to treat
stockpiled and other necessary areas within no more than two construction seasons. Also,
the parties understand that portions of some highly contaminated soils areas not
immediately excavated due to the desire to minimize volume in the stockpile will be
revisited and excavated as soil treatment capability comes on line.
We request that the PP be amended to account for our comment letter to you of March 11,1998,
our comment fact sheet presented at the public meeting and our statement at the meeting.
i
Response - U.S. EPA believes that this Responsiveness Summary adequately addresses all
comments submitted by WDNR,
We request that the PP revisions or amendment be mailed to your site community relations
mailing list and the comment period be extended by 30 days past the date of mailing or 30 days
past the current deadline to allow the public to review these changes and comment on them.
Response - U.S. EPA extended the public comment period by 30 days, and advised the
public of this through a newspaper advertisement, voice mail advisement to callers
concerning the Moss-American comment period, and notice on U.S. EPA's Region 5 Home
Page.
If you do not intend to honor these requests, we ask that you reply directly in writing to this letter
and provide an explanation as to why you will not honor them.
Response - As noted above, the April 14,1998 correspondence from U.S. EPA constituted
such reply.
Regardless, we ask that the comment period be extended by 30 days to allow this matter to be
resolved.
Response - U.S. EPA extended the public comment period by 30 days, and advised the
public of this through a newspaper advertisement, voice mail advisement to callers
concerning the Moss-American comment period, and notice on U.S. EPA's Region 5 Home
Page.
from S. W. Thornton - Milwaukee - dated April 3,1998
(Note - Due to the length of the correspondence, U.S. EPA presents excerpts of what appear to be
the most significant comments)
-------
16
Although the 65 acres of land owned by Milwaukee County are currently undeveloped
recreational land, there is no permanent absolute that this land will remain undeveloped or that
the zoning will not be changed to residential.
Response - U.S. EPA appreciates the citizen observation that site land owned by
Milwaukee County appears to be for recreational usage. U.S. EPA infers from
commenter's statement that current zoning for County land is other than residential, but
will make further inquiry on this matter. Per terms of the existing RD/RA Consent Decree,
U.S. EPA would expect the Settling Defendant in this matter to seek other deed restriction
or limitation as may be pertinent from the property owner. If this cannot be arranged,
then cleanup to the residential scenario would be necessary, which would appear to be most
pertinent to the direct contact component regarding needed remediation. U.S. EPA
believes it is prudent to await pertinent recommendations as may develop from natural
resource trustee and Settling Defendant discussion before addressing the County owned
portion of the floodplain as a whole, i.e., for floodplain located outside of the former wood
preserving plant.
Furthermore, there is no long term certainty that direct exposure hazards and any contamination
containment caps will be adequately maintained of funded by future generations.
Response - In the remedial action consent decree, now entered by the Court, it has been
determined that the prohibition of excavation of the final cover of the landfill as set forth in
Wisconsin Administrative Code NR 504.07(8) is necessary to implement the remedial
action for the facility to protect the public health and environment The Settling Defendant
in this matter, the KMC, has provided per terms of the Decree financial assurance for the
work, which includes not only capital construction but also necessary operation and
maintenance. Also, the Decree provides for the periodic review by U.S. EPA of the
remedial action to assure that human health and the environment are being protected by
the action so implemented. There is some ambiguity between the Consent Decree and its
Statement of Work as to how long cover maintenance should be provided. U.S. EPA
believes, as stated in the ROD amendment, that because of the slow rate of decomposition
which might be expected from more complex PAHs, that it would be prudent to provide for
financial arrangement such that the cover may be maintained in perpetuity.
There has already been several reported incidence's of direct exposure skin irritations and
various degrees of skin burning in and around the area, including various areas nearby and down
stream of the Little Menomonee River.
Response - U.S. EPA is concerned with such findings. The issues under consideration in
the Proposed Plan will help to alleviate such condition, though a discussion of sediment
management strategy, which U.S. EPA feels is warranted in the near future, will focus
attention on this area.
-------
17 .
Many people are not aware of the dangers of this site, thereby allowing their children to play in
these fields, streams and at other areas, including around rail road tracks and the Union Pacific
site when it is unattended/under supervised.
Response - Through the issuance of several fact sheets concerning site status which have
been issued since the 1990 ROD, U.S. EPA has attempted to inform the public about the
site. The great majority of Union Pacific property at the site is fenced. (Certain frequently
utilized train tracks are not fenced, of course.) Union Pacific representatives inform U.S.
EPA that contracted personnel conduct business on Union Pacific property during normal
working hours, and that a security guard is on duty 24 hours per day.
People take their pets through this waterway and often raft the river. Furthermore, pets and
wildlife drink out of the river. ,
Response - U.S. EPA has received groundwater treatment system design plans from KMC
and its consultant. U.S. EPA has indicated conditional approval thereof, and is hopeful
that the groundwater collection and treatment system will aid in preventing a significant
portion of potential contamination from the site from entering the stream. Ensuring
proper erosion control measures are taken, as proposed in the plan, will also help.
Sediment management will aid further. Of course, the remedy is considering the Moss-
American site in particular. U.S. EPA cannot guarantee that the introduction of some
objectionable item into the Little Menomonee River, unrelated to the site, cannot occur at
some point. One must also consider the frequency with which exposure of pets to site
conditions occurs. A residential exposure scenario would assume daily exposure; a
recreational scenario occasional exposure to the site.
Proposing that the area used by Union Pacific remains zoned as industrial with the hopes that it
will remain industrial...is no sure way to assure that goal The less chance...is still too great
Response - One of the important instructions of administrative reform is to consider more
realistic land usage patterns. The argument that a given piece of property may not always
stay industrial, and that there is no absolute certainty could be used anytime, anywhere to
negate any exposure scenario other than residential. But the Union Pacific portion of the
site has been used for more than 18 years in an industrial fashion, as was indeed the site as
a whole since the early 1920s. The public has a right to expect a protective cleanup. But
U.S. EPA is urged, via the administrative reforms, to think more realistically concerning
site usage patterns. Should a set of circumstances arise when industrial usage of at least a
portion of the site does not seem a realistic assumption, U.S. EPA would reserve the right to
seek modification of the remedy at some future time to reflect more up-to-date exposure
scenarios. Should, for some unforeseen reason Union Pacific not be willing to incorporate
industrial deed restrictions upon their site property, despite their indication of willingness
to do so, then U.S. EPA has stated in the ROD amendment that cleanup to residential
-------
18 .
exposure would occur.
The 3.1 ppm standard should be the only one minimum standard considered here for the entire 88
acres.
Response - U.S. EPA disagrees. The entire 88 acres includes the corridor of the Little
Menomonee River and the river's floodplain. It would seem unrealistic to assume
industrial development in the floodplain, especially when biking/hiking trails predominate
in County lands further downstream.
Considering the recreational use exposure scenario of Alternative 2 is absolutely out of the
question.
f
Response - As set forth in the ROD, a change in the risk scenario is contingent upon
securing appropriate deed restrictions. As noted in the previous response, industrial
development in this floodplain is highly unlikely. Furthermore, given recent activity
concerning an easement on County land to accommodate a prospective industrial user, and
the existence of the hiking/biking trails adjacent to the river farther downstream, plus the
existence of the Park and Open Space plan as endorsed in 1991 by the Milwaukee County
Board of Supervisors, there seems ample reason to consider recreational usage for a
portion of the site.
In addition, it is important to assure the emissions collection meets all Wisconsin regulatory
standards.
Response - U.S. EPA concurs.
The possibility that this land could be used in the future as a residential site presents favorably
that the entire area be treated as residential for all exposure levels.
Response U.S. EPA disagrees. The railroad has indicated its willingness to restrict
residential usage on its land. Recent development on County land involving the former
wood preserving facility was to seek easement for industrial usage, not residential. The
Park and Open Space plan adopted by the County in 1991 clearly calls for enhancement of
recreational opportunity in the river corridor.
In addition, current owners must be held responsible for disruption of any original contamination
remaining following the completion of the remediation which may cause reoccurrence.
Response - U.S. EPA believes there should be flexibility in the interpretation of which
person may be responsible for operation and maintenance duties concerning remedy
implementation. U.S. EPA believes that the likelihood of either Union Pacific or
Milwaukee County engaging in some disruption of the completed remedy would be very
-------
19
remote, but U.S. EPA would in such event strive to prevent reoccurrence of contamination
problems.
According to Mr. Edelstein, many of the alternatives being considered...were not fully disclosed
in writing within the revised remedial action plan and/or Record of Decision (ROD). I insist that
all changes to the original ROD be clearly identified in writing. I strongly suggest that, despite
whatever is entailed in the original ROD, that the maximum protection or no less than 3.1
exposure levels be implemented for the entire 88 acres and placed in writing. This must be done
before the acceptance of the remedial action plan by the WDNR.
Response - The term "alternatives" has specific meaning within the context of proposed
plan presentation. U.S. EPA checked with WDNR on this matter. WDNR clarified that it
would have been more accurate to say that there was concern over lack of certain details,
as opposed to entire alternatives being omitted. The term "maximum protection" could
also be construed to mean only a residential exposure scenario. Again, WDNR clarified
that provided other concerns it raised were addressed satisfactorily, that a non-residential
exposure scenario could be adopted for at least portions of the site. U.S. EPA will indeed
put any changes to the ROD in writing. The original ROD called for residential exposure
assumptions regarding the site. A key purpose of the current proposed plan is to
reevaluate this position. Given the continued industrial usage at a portion of the site, and
the condition imposed in the remedial action decree which stipulates that the site is not to
be used for residential usage, U.S. EPA believes a change is prudent.
Although cost effective planning is critical, above all else, the protection of human and
environmental health and safety must be assured foremost. Economics and politics are all too
often primary at the expense of human and environmental health and safety... Hence, "Band-
Aid" solutions will only pass on additional hazards and shift costs to future generations. Short
term, low cost solutions will not provide long term human, wildlife, and natural resource
protection! Wisconsin residents, recreational visitors, and especially those of us who live within
the boundaries of risk due to this area, need to be certain that this site and the surrounding risk
assessed areas, for what ever degree of risk is present, is as safe as it can be! The remedial action
plan must be specific and conclusive in resolving these issues... Let those who contaminated the
site pay for its cleanup and not through addition taxes.
Response - U.S. EPA is expected to conduct remediation of Superfund sites in a manner
conforming to the National Contingency Plan (NCP). When remediation is required, the
NCP has an expectation that excessive carcinogenic risk to site users will be within the one
in ten thousand to one in one million range. Soil cleanup numbers discussed in the plan
represent a one in one million source of additional carcinogenic risk to a given class of site
user. The proposed plan discusses remediation which would provide for both treatment
and containment of site soils. Through treatment of more highly contaminated soils areas,
U.S. EPA expects the remedy to provide long-term effectiveness and permanence. U.S.
EPA does not therefore expect to be passing a problem along to future generations. Other
-------
20
elements of the remedy for which a need for remediation has been determined include
groundwater and sediments management. The estimated net present worth of the cost of
undertaking needed capital construction and long-term operation and maintenance efforts
was placed at $26 million at the time of the 1990 ROD. While U.S. EPA is hopeful that
changes in treatment technique may help to reduce that figure, the effort to conduct
remediation at the Moss-American site is expected to remain considerable. U.S. EPA does
not view a multi-faceted approach such as this, which features treatment as an important -
component, to the lower end of the acceptable risk range to represent a "Band Aid" effort
at remediation. If U.S. EPA were to advocate a remedial measure featuring a more
stringent cleanup than called for by the NCP, then citizens, as opposed to "those who
contaminated the site," could very well be called upon to pay for extra cleanup costs taken
which arguably were not in conformance with the NCP.
I
from G. J. Deigan - Libertyville, Illinois - dated April 6,1998
(Note - Due to the length of the correspondence, U.S. EPA presents excerpts of what appear to be
the most significant comments)
I understand that U.S. EPA and WDNR support the use of risk-based clean-up standards that are
protective of human health under two land use scenarios at the site; industrial land use on the
parcel owned and operated by the Union Pacific Railroad; recreational/trespasser land use on the
parcels owned by Milwaukee County. These standards should be approved by U.S. EPA and
WDNR and incorporated into the revised remedy. Union Pacific (UP) apparently endorses these
standards and recognizes the adequacy and protectiveness afforded by these industrial land use
standards... it is probable that the remedy can be implemented on and adjacent to the UP
property without shutting down or appreciably impacting the active rail car unloading
operation...
Response - U.S. EPA offers this clarification. From correspondence received from UP,
there appears to be endorsement by that entity of usage of industrial exposure scenario risk
evaluation on its land. Because of the land usage pattern on UP property, and the apparent
willingness of UP to enter into appropriate deed restriction, U.S. EPA advocates the
industrial exposure scenario for this portion of the site. U.S. EPA does not necessarily
advocate recreational usage for all Milwaukee County site property. Per terms of Consent
Decree restrictions, County site property consisting of the former wood preserving facility
cannot be construed as for residential usage. Given recent attempt to grant an easement to
a prospective industrial landowner on an uplands area of County property within the
former wood preserving facility, U.S. EPA takes the position that non-floodplain portions
of County property on the site should be industrial, so as to be consistent with the UP
portion. Because of the obvious recreational usage of County property farther to the south
along the river corridor, U.S. EPA believes floodplain portions of County property should
be protected so as to meet a recreational exposure scenario. This is consistent with Tables
1-b/l-e of the 1990 ROD, which viewed the Little Menomonee River corridor as
recreational. However, U.S. EPA will address the river corridor outside of the former
-------
21
wood preserving facility prior to more active sediments management work involving the
site. Should arrangement to provide for needed deed restriction or other limitation fail to
occur with a given property owner, then default to the residential scenario would be
necessary.
Based on comments made by a Milwaukee County representative at the March 18,1998 public
hearing, however, it does not appear that Milwaukee County will support the use of a
recreational land use clean-up standard on its parcels of the Moss American site. I believe the
County is not adequately informed on this matter, and as a result may be taking an improper
political position on this issue... More stringent residential or industrial cleanup standards
applied to the County Parcel will only further damage the emerging and mature habitats that have
developed on the inactive wood treating site and the Little Menomonee River's riparian buffer
zone... The imposition of deed restrictions that recognize future recreational/open space is
consistent with the County Department of parks mission and charter and is not unreasonable.
The County's unwillingness to support this alternate cleanup standard is a disservice to the
public...
Response - U.S. EPA is not aware that any action has been taken by the County Board of
Supervisors to withdraw endorsement of the 1991 Park and Open Space plan. Such plan
clearly calls for recreational usage and development within the Little Menomonee corridor.
However, the comment concerning "emerging and mature habitats" would appear to be
more pertinent to the riparian zone, rather than upland areas. As indicated earlier, the
adoption of different exposure scenarios is contingent upon obtaining appropriate deed
restrictions.
WDNR and U.S. EPA have had a history of continued technical and regulatory disagreements
and conflicting agendas at this Superfund site. This dissension among the two Agencies has
unnecessarily delayed the remedial action progress at the Moss American Site, and resulted in
excessive administration, engineering and communication costs that should have otherwise been
beneficially spent on remediation or restoration of the site. U.S. EPA and WDNR should allow
the responsible party to develop its technical plans and implement its proposed remedy... As a
first step in addressing this issue, U.S. EPA should amend the existing Consent Decree to
incorporate a revised statement of work and eliminate the three party Consent Decree. A two
party Decree should be executed between U.S. EPA and the settling defendant for the revised
remedy.
Response - While U.S. EPA cannot predict future matters, up until the present U.S. EPA
and WDNR have officially disagreed only on the matter of appropriate management of
concentrated recovered free-product creosote. U.S. EPA does not believe that this imposed
an undue burden upon the settling defendant. The primary source of delay in conduct of
the remedy was the filing of objections to entry of the Decree calling for remedial action.
These objections, filed in 1991 by major site property owners, were not withdrawn until
1996/7. It could be argued that the settling defendant benefited substantially from the
-------
22 .
standpoint of cost avoidance during this period. By the time that period ended, the concept
of administrative reforms was in place, causing U.S. EPA to consider their logical
application on this site which may have the effect of cost savings in the conduct of the
remedy. U.S. EPA and WDNR did concur on the matter of letting groundwater design
proceed utilizing the relatively innovative funnel and gate concept. Successful operation
could yield significant savings to the settling defendant. The agencies also concurred on the
matter of temporary soils stockpiling, which provides further flexibility in ability to begiir
groundwater management development providing good effort is made to get soils treatment
capability on-line quickly, defined as no more than two construction seasons. As regards to
the comment that the agencies should let the settling defendant develop technical plans and
proceed, U.S. EPA recalls that when documents were submitted concerning another look at
soils alternatives that in many cases the covers proposed for utilization bore no
resemblance to dimensions specified by either ARARs or-the 1990 ROD.
During the March 18, 1998 public meeting, several questions were asked by members of the
public regarding the safety of the site to the public and children in the event they were to play in
or near the river, walk their dogs, etc. Responses by the U.S. EPA and WDNR during the public
meeting did not allay these concerns and in fact seemed to leave the public with the impression
that there was an imminent and substantial threat by the current pre-remedial conditions of the
site and the river...
Response - U.S. EPA does indeed believe that the site poses an imminent and substantial
endangerment to human health and the environment. While some of the sources of the
contamination have been removed, significant risks remain as evidenced by the
administrative record and recent groundwater monitoring data.
U.S. EPA and WDNR unveiled proposed cross-sectional plans for a multi-layer engineered soil
cover system that consisted of approximately 54" of cover soil. This cover soil is intended to
preclude direct contact by humans... This cover system is excessive for its intended purpose...
This thickness of cover will require that a substantial volume of fill soil be imported and placed
on the site... such quantity of fill will adversely impact the community, the site and the
surrounding environment by: raising the elevation of the site and altering the drainage patterns of
the localized watershed..., increasing the potential for erosion and sediment loads in the river...,
disturbing emerging and maturing habitats and land features...that have developed since the
cessation of wood treating operations, including ephemeral ponds, emerging wetlands, scrub-
shrub habitats, and compatible riparian land features, creating an elevated land fill that reduces
potential future beneficial development..., increasing the disturbances to the surrounding
community by short term construction impacts..., decreasing the usability of the railroad
property... Infiltration of precipitation is viewed as an unnecessary objective of the cover system
since soils will be treated to levels that are protective of groundwater (i.e., groundwater RCLs)
and the site wide "funnel and gate" groundwater treatment system will provide containment and
treatment of any migrating residual contaminants.
-------
23
Response - U.S. EPA disagrees that control of infiltration is unnecessary. The 1990 ROD
envisioned flushing of the soils as beneficial in carrying along perceived slight contaminant
loads to the groundwater such that groundwater restoration objectives could be
accomplished quickly. The finding in the pre-design sampling of more extensive deposits of
free-product creosote changed that earlier presumption. Most Superfund remediation
strives to limit infiltration; modifying this concept on the Moss-American site would bring
site management more in line with most other remedial efforts. Moreover, as was
explained in the proposed plan and meeting, the cover system now proposed is not by any
means the most rigorous form of containment that could be imposed given the hazardous
substances encountered, U.S. EPA is not advocating a liner and leachate collection system,
providing that soils treatment efficiency can attain pertinent treatability variance values
and pertinent groundwater residual contaminant values for the three compounds which
are promulgated under WDNR rules and are of obvious groundwater concern at the site
and in need of further source control efforts. Furthermore, the adverse consequences the
comments foresee regarding emerging wetlands, ephemeral ponds, etc., are more pertinent
to floodplain site locations. Consolidation of contaminated soils and the covering thereof is
not expected to be placed within the floodplain, but rather on upland areas of the site.
U.S. EPA's proposed plan calls for potential thermal desorption of sediments from the Little
Menomonee River. This approach should be reconsidered by U.S. EPA for a variety of...
reasons, including: the criteria for soils treatment by thermal desorption is to treat those highly
contaminated soils having BAP-equivalent concentrations greater than 78 ppm for CPAHs. The
sediments in the river do not contain these levels of CPAHs...; the sediment dredging and river
remediation will likely not be conducted in a similar timeframe as the on-site soil remedy. Thus,
the thermal desorption unit will have to be re-mobilized and/or operated at the site for an
extended period of time... This is an unnecessary burden...without appreciable environmental
benefit; The contaminants in the river sediment may include non-point source and non-site
related contaminants that may not be fully characterized or appropriate for thermal desorption
treatment and air emission controls... [such as]... heavy metals, PCBs, and other compounds...
These contaminants are more appropriately managed by ...a soil cover system-
Response - Page 9 of the Statement of Work (SOW) for the remedial design and remedial
action work plan which is a part of the Consent Decree states in part... "in the portions of
the channel of the Little Menomonee River which are not rechanneled...Settling defendant
shalL..treat sediment containing in excess of..." Hence, to be consistent with the Consent
Decree, U.S. EPA must advocate treatment of sediments as appropriate. U.S. EPA also
points out that the reason for excavating and treating a certain soils "hot spot" is not only
its CPAH concentration, but also whether a given area may be associated with free-product
creosote. Such reasoning should apply to the stream as well. It is speculative at this time to
judge whether dredging might ever play a more prominent role in sediments management
at this site than what is now envisioned, but if such instance arose it might be prudent to at
least allow for sediments treatment such that design for sediments containment might be
more in line with design for treated soils. Were dredged sediments untreated, and
-------
24
containing listed hazardous wastes, containment would necessitate liner and leachate
collection (or solidification measures) utilization. The presence of PCBs would still appear
to be compatible with thermal desorption usage. The presence of excessive levels of heavy
metals in the sediments could interfere with either a bioslurry or thermal desorption
treatment approach. Further sampling to determine the presence of heavy metals may be
warranted.
I am concerned, however, that the Trustees, particularly WDNR, will promote a level of river
remediation that is far beyond that required for protection of human health and the environment,
and beyond the scale of impacts caused by the former wood treating operation. WDNR
continues to advocate for a complete rerouting and development of a new river channel despite
credible studies that indicate substantial environmental damage...from such an action... In lieu of
a complete re-routing of the Little Menomonee River, WDNR continues to advocate for
excessive dredging, unrealistic sediment quality standards, and restoration measures that are
highly destructive to the existing emerging and mature habitats that have developed along... the
river... In this case, the less destructive remediation plan should prevail in the interest of benefit
to the environment and the community...
Response - The proposed plan does not address possible modification of sediment
management approaches at the site. The 1990 ROD calls for river reroute. That is
unaltered by the proposed plan. U.S. EPA has discussed possible dredging techniques
which may be of interest on this site with remedial action signatory parties. However,
concerning certain key logistical matters, for example, U.S. EPA never received assurance
that appropriate containment steps would be used for dredging spoils, or that verification
analysis would be an integral component of any dredging technique utilized. As such, U.S.
EPA could not advocate a plan to significantly modify sediments management. It is
possible, after examining areas of environmental injury, that the federal/state natural
resource damage trustees may have some ideas or recommendations as to bring together
concepts of remediation and restoration. U.S. EPA is not a natural resource trustee.
CERCLA discusses resource liability as well as remediation efforts. To resolve all
CERCLA liability, it may be in the interest of the Settling Defendant to consider
approaches which if undertaken at one time might resolve remediation and restoration
matters. U.S. EPA will note with interest trustee recommendations. If warranted, U.S.
EPA would be the agency to prepare a proposed plan to consider implementation of trustee
concepts should these relate to an alteration to sediment management concepts for which
public comment is sought.
U.S. EPA and WDNR made some very recognizable mistakes in their 1990 remedy selection -1
trust that federal, state, and county politics will not result in a repeat of this history during revised
remedy selection some 8 years later.
Response - The key alterations which U.S. EPA advocates in this proposed plan are to
consider adoption of non-residential usage scenarios for at least portions of the site, and to
-------
25
adopt a different soils and sediments treatment technique. The first change comes about
through consideration of administrative reforms adopted in the period 1993-1995; the 1990
ROD did not have the benefit of this guidance. The suggested treatment method change
comes about after reviewing data results for wood preservative sites which has been
amassed over the 1990s, which indicates that thermal desorption may be a better choice in
instances where more complex forms of CPAHs, unencumbered by dioxin/furan
complications, predominate. U.S. EPA did not have this information in 1990, either.
However, U.S. EPA has attempted to be fair in its consideration of application of this newer
information to site management
from E. H. Bryan, Ph.D. - National Science Foundation - Arlington, Virginia - dated April 24,
1998
1
Thank you for your E-mail note regarding Moss American and the Little Menomonee River...
My interest in that project relates to having been involved in discovery of the problem as a
member of the Citizens for the Menomonee River Restoration (CMRR) and then its President
and Principal Investigator of the EPA contract that led to the production of the film "Once a
River". This film documented the process by which the problem was discovered and two
research/demonstration projects conducted in 1972 on methods to decontaminate the sediments...
I was in contact with your Bonnie Eleder in June of 1993 and sent her a video copy of that film...
I'd like very much to be informed of items such as those I've been able to retrieve from the web
relating to our progress toward cleaning up this site...
Response - U.S. EPA appreciates the efforts made by concerned citizens in this matter.
U.S. EPA does have the video copy of the film to which the commenter refers. U.S. EPA
will indeed attempt to keep interested citizens informed of progress concerning the site.
from T. P. Graan, Ph.D. - Roy F. Weston, Inc. - on behalf of Kerr-McGee Chemical LLC (KMC)
- dated May 8,1998 (Note - Due to the length of the correspondence, U.S. EPA presents excerpts
of what appear to be the most significant comments)
"...As indicated by our past submissions to U.S. EPA, the bioslurry treatment technique
recommended in the 1990 ROD is not effective. Moreover, guided by current EPA policy as
implemented at other CERCLA sites, it is also appropriate to adopt significantly larger cleanup
standards for the Site. We thus strongly endorse EPA recognition of these facts in the Proposed
Plan..."
Response - In general, U.S. EPA concurs with the comment. U.S. EPA would add that the
bioslurry treatment technique does not seem to be effective at this site. U.S. EPA also adds
that cleanup standards for this site should consider non-residential usage exposure
scenarios.
Comments on the Proposed Plan
-------
26
1. "...far more extensive alterations of the remedy are required than those now being considered
by U.S. EPA... very significant modification of the remedy for sediments in the Little
Menomonee River is necessary. It is now apparent that the 1990 ROD remedy for sediments
would create significant adverse ecological impacts throughout 5 miles of river corridor. U.S.
EPA suggests... that a revision of this aspect of the remedy may be undertaken in the future.
Although KMC is of the view that the available information shows that the river remedy must
now be changed, KMC is prepared to support a limited modification of the ROD along the lines
of the Plan... with the understanding that such a change will be without prejudice to subsequent
further modifications of the ROD..."
Response - The Proposed Plan did not address any recommended changes in sediment
management As noted in the Proposed Plan, U.S. EPA is hopeful that discussions
involving natural resource trustees, and which may eventually involve parties to the
remedial action consent decree, will examine means by which remediation and restoration
concepts can be best integrated into sediment management at the site.
2. "...While U.S. EPA has stated its intention under Alternative 2 to adopt an industrial use
exposure scenario for the railroad property, it states only that it will consider a change to a
recreational use scenario for the County property. We believe that the KMC submissions
establish that a change in the exposure scenarios for both the railroad and the County land is now
appropriate and we urge to U.S. EPA to establish the revised cleanup standards for both
properties now. If EPA fails to act with respect to both properties, there will be a need in the
future to revise the ROD yet again...
...the Plan fails to mention that the cleanup standards are expressed as benzo(a)pyrene equivalent
concentrations, an approach that is consistent with both U.S. EPA and WDNR guidance... We
recognize that EPA may understand and intend this interpretation of the cleanup standard, but we
urge clarity on this point in the revised ROD..."
Response - Because of the land usage pattern on Union Pacific (UP) property, and the
apparent willingness of UP to enter into appropriate deed restriction, U.S. EPA advocates
the industrial exposure scenario for this portion of the site. U.S. EPA does not necessarily
advocate recreational usage for all Milwaukee County site property. Per terms of Consent
Decree restrictions, County site property comprising the former wood preserving facility
cannot be construed as for residential usage during the performance of the work.
Regarding the former wood preserving facility, and being mindful of recent effort to seek
easement for an industrial facility on an upland section of this facility, U.S. EPA takes the
position that non-floodplain portions of the former wood preserving facility should be
industrial, so as to be consistent with the UP portion. U.S. EPA will defer classification of
County property along the river corridor to a later time so that it is consistent with
sediment management objectives. It may be argued that because of the obvious
recreational usage of County property farther to the south along the river corridor,
floodplain portions of County property should be protected so as to meet a recreational
-------
27
exposure scenario. This would be consistent with Tables 1-b/l-e of the 1990 ROD, which
viewed the Little Menomonee River corridor as recreational. The revised ROD (ROD
amendment) notes the concept of benzo(a)pyrene equivalent, which is appropriate when
considering the direct contact exposure pathway. However, with regard to groundwater
management, it is more appropriate to consider the specific compound(s) shown to be of
concern, and to manage the remedy such that these particular compounds no longer pose a
continuing source threat. Upon review of monitoring data for the Moss-American site, -
naphthalene, fluorene, and benzo(a)pyrene appear to warrant such management.
3. "...The Proposed Plan states that contaminated soil will be treated in a low-temperature
thermal desorber, but does not clearly specify that only highly contaminated soil will undergo
treatment... In its discussions with U.S. EPA and WDNR, KMC has agreed to treat soils
exceeding 78 ppm CPAHs (BAP-equivalent), and soils identified in the RI as containing BTEX
compounds in excess of NR 720 generic migration-to-groundwater values... The revision of the
ROD should clearly state these limits, however, so that there will be no confusion as to the soils
that will be treated..."
Response - In its discussion of the "Recommended Alternative", the proposed plan notes
that "...U.S. EPA sees potential benefit in adopting thermal desorption (Alternative 2) as a
treatment approach for highly contaminated soil/sediment at the Moss-American site..."
U.S. EPA concurs that CPAH u noted in terms of benzo(a)pyrene (BAP) equivalent, and
believes that the areas KMC/Weston have elected correspond well with the agency's
working definition of "hot spot" from a standpoint of toxicity protection. U.S. EPA would
add that another reason to treat soils is to further attempt to manage those areas which
may be associated with free-product creosote. As noted in the proposed plan in
Recommended Alternative discussion, plus Figure 1, U.S. EPA expects thermal desorption
treatment would be extended to soils areas having more highly contaminated CPAH levels
(78 ppm), are associated with free-product creosote, and/or contain BTEX compounds
posing a threat under NR 720 generic migration-to-groundwater values. Additionally, as
discussed in the ROD amendment, U.S. EPA has added the compounds naphthalene,
fluorene, and benzo(a)pyrene and points encountered from the RI which indicated high
areas of such compounds. This is because of the presence of these compounds in
monitoring wells in excess of PALs and the need to control nearby soil areas.
4. "The Plan states that some contaminated sediments may undergo treatment in the LTTD...
More importantly, in contrast to soils, LTTD treatment of contaminated sediments is not
appropriate from a practical and logistical standpoint. Site soils requiring LTTD treatment could
be excavated, temporarily stockpiled, treated, and placed back on site within one field season.
The treatment of soils would thus require only one mobilization/operation/demobilization of the
LTTD unit. On the other hand, sediment removal from the Little Menomonee River is expected
to occur over several years. Sediments requiring treatment might be encountered at various
locations throughout the river during the entire time period of sediment dredging, thus requiring
either: (1) multiple-year temporary storage of untreated contaminated sediments at the site
-------
28
followed by LTTD treatment after all sediments are excavated, or (2) multiple
mobilization/operation/demobilization sequences for the LTTD unit. Neither of these options is
cost-effective or environmentally desirable. In addition, KMC is puzzled at the statement that
"contaminated sediment areas where sediment is removed by dredging techniques near bridges
may also undergo thermal desorption treatment." There appears to be no logical or practical
reason why the location of sediment should govern the determination of whether to treat that
sediment..."
Response - In considering the logistics of the matter, U.S. EPA is not necessarily convinced
of a main premise put forward by the commenter; namely that there will be a considerable
disparity between time needed to accomplish soil treatment objectives (one field season)
versus time needed to accomplish sediment management objectives if dredging were
featured on a larger scale than now envisioned (several years). U.S. EPA recalls discussion
on the matter of dredging where KMC representatives estimated four years if work were
done mainly in the spring and summer. However, U.S. EPA noted that many sediments
management projects might be best conducted during all seasons except spring, when
siltation control aspects of the work might be most difficult A more aggressive program, if
dredging were featured more prominently than now envisioned, might be accomplished in
two years. Hence, if time estimates to accomplish soils and sediments work are brought
closer together, there is less concern over multiple LTTD mobilizations and extensive
storage periods. It is speculative at this time to judge whether dredging might ever play a
more prominent role in sediments management at this site than what is now envisioned, but
if such instance arose it might be prudent to at least allow for sediments treatment such
that design for sediments containment might be more in line with design for treated soils.
Were dredged sediments untreated, and containing listed hazardous wastes, containment
would necessitate liner and leachate collection (or solidification measures) utilization. Page
9 of the Statement of Work for the remedial design and remedial action work plan which is
a part of the Consent Decree states in part... "in the portions of the channel of the Little
Menomonee River which are not rechanneled...Settling Defendant shalL.treat sediment
containing in excess of..." Hence, to be consistent with the Consent Decree, U.S. EPA must
advocate treatment of sediments as appropriate. U.S. EPA also points out that the reason
for excavating and treating a certain soils "hot spot" is not only its CPAH concentration,
but also whether a given area may be associated with free-product creosote. Such
reasoning should apply to the stream as well.
Comments on the 18 March 1998 Public Meeting
1. "...During the course of the meeting, U.S. EPA presented diagrams of three cover/liner designs
that were portrayed as the options U.S. EPA is considering for LTTD-treated soil... KMC was
startled to learn at the meeting that U.S. EPA is considering cover/liner designs that differ so
significantly from those that have been the subject of our discussions... the proposed liner/cover
designs are troublesome because U.S. EPA seems to have made the unfounded assumption that
treated soils somehow pose a greater environmental threat than untreated soils... KMC believes
-------
29
that post-treatment analytical results should be the guide as to how the treated soil should be
managed at the site..."
Response - U.S. EPA believes that reasoning behind the thinking in the 1990 ROD to
deliberately employ a permeable cover that promotes water infiltration so as to enhance the
flushing of soil contaminants into groundwater as a means of hastening groundwater
remediation time is no longer valid, given the finding of more free-product creosote at the
site than was envisioned at the time of the 1990 ROD. Hence, a permeable soil cover is no
longer warranted. A containment unit for a hazardous waste should logically provide for
subsurface management in the form of a liner and leachate control system. However, U.S.
EPA adopts the view that if treatment is provided first, and RCLs for groundwater are
attained, only cover measures need be employed provided as is explained in the ROD
amendment a CAMU is used and the appropriate degree of protectiveness is reached as
may be stipulated under federal or State rule pertaining to its usage, e.g., ch. NR 636. This
assumes that treatment efficiencies in Land Disposal Restrictions or treatability variance?
thereto are attained. However, U.S. EPA does believe that post-treatment analytical results
should help guide subsequent soils containment efforts. If indeed all excess direct contact,
runoff, and groundwater migration threats are brought to satisfactory levels, then the
residuals could be managed in very simple fashion, and protection from undue erosion
would be the only foreseeable management concern.
2. U.S. EPA stated that the LTTD unit would operate at temperatures between 500-900F. Most
LTTD contractors have suggested an operating temperature of 1,000- 1.200F for the specific
conditions at the Site.
Response - The example given was to show a typical working range for the low temperature
thermal desorption technology as contrasted to incineration, which is conducted at
approximately 2200F. (See page.21 of the transcript of the public meeting). Later on in the
meeting, (see page 33 of the transcript) U.S. EPA noted that particularly efficient CPAH
removal efficiency had been realized using LTTD at one creosote site at an operating
temperature of 900F. This is not greatly different from the operating temperature
suggested by the commenter, and U.S. EPA appreciates this information.
3. "...U.S. EPA stated at the meeting that sediment cleanup would extend through mile 5 of the
Little Menomonee River. We were startled by this statement because we thought that the parties
had reached a common understanding that sediment cleanup would involve only the first three
miles plus approximately one half of mile 4... the data suggest that even this cleanup - to which
KMC acceded only to achieve compromise - is far more extensive than the circumstances
warrant... We also understand that the current revisions of the ROD will not cover this matter and
that a further revision will take place in the future on this and related subjects. Nonetheless, we
hope that the U.S. EPA's comments do not reflect a retreat from the compromise that had been
obtained in our discussions..."
-------
30 .
Response - As of discussions among the remedial action signatory parties through March
1997, conceptually the parties were indeed thinking in terms of sediment cleanup extending
through segment 3 and including about half of segment 4. This was based on segment by
segment comparison of sediment CPAH content with maximum probable background
(MPB) values as calculated per segment by WDNR. That U.S. EPA should express a
different view as to linear stream distance requiring remediation should not startle
Weston/KMC, since after all it was a proposal presented by Weston/KMC which caused -
the change. In August 1997, both in a meeting with the signatory parties and in a
subsequent conference call, Weston/KMC proposed that WDNR adopt one overall average
value MPB for the stream, rather than utilize a segment by segment approach.
Weston/KMC suggested the value be approximately 15 ppm CPAH, representing an
overall average of the segment values. WDNR subsequently adopted this value, and it
serves as a measure of what should necessitate runoff protection as well. However, once
that was done, the view of what should happen with segment 5 changes. The "per segment"
MPB approach yielded an MPB of about 26 ppm for segment 5, and it was arguable given
the Remedial Investigation (RI) and pre-design sediment data that segment 5 could be a no-
action zone. However, when the value of 15 ppm CPAH is applied, segment 5 should be
remediated.
4. "...The Milwaukee County Supervisor made statements that reflect a misunderstanding of the
terms of the Consent Decree... In particular, KMC has nd agreed to spend $ 26M for
remediation... Although KMC... provided U.S. EPA with financial assurances demonstrating that
KMC could fund a remedy with a cost of that magnitude, KMC is under no. obligation to spend $
26M at this site...
The Plan, as modified to reflect these comments, takes U.S. EPA part of the way along the path
that it is required to follow... We would appreciate it if you would include these comments in the
administrative record that you maintain for this Site..."
Response - U.S. EPA concurs with the Weston/KMC interpretation of this matter, namely
that KMC did provide financial assurance of its ability to conduct a remedy having a net
worth of $26 million. However, KMC is not obligated to spend that amount if the remedial
goals can be accomplished in a manner incurring less cost. U.S. EPA will indeed include
these comments in the administrative record. U.S. EPA notes briefly that its actions in
reviewing conduct of the remedy are driven in large part by administrative reforms
pertinent to certain subject matters concerning the Moss-American site. While U.S. EPA
strives to implement such reforms, they are not actually a matter enacted into law and as
such U.S. EPA may not necessarily be "required" to implement such review of the remedy.
-------
31
Oral Comment - Compiled from the transcript prepared of the March 18, 1998 public meeting
held in room 180 of Vincent High School, Milwaukee, Wisconsin.
from J. McGuigan - I'm County Supervisor, Milwaukee County. You commented about
recreational use of the site in the park and open space plan which, by the way, is from the
SEWRPC [Southeastern Wisconsin Regional Planning Commission] that was passed five years
ago, and while there may have been approval from...the supervisor at the time, we have a new -
man in town who doesn't approve. Also, I wanted to make a correction. The consent decree
between the County, Moss-American, and Kerr-McGee says that...says that the parks will be off
limits indefinitely, so we're not looking at any recreational use for this plan or for this area.
Response - U.S. EPA has received a copy of a June 20,1991 resolution adopted by the
Milwaukee County Board of Supervisors. This states in part "...Whereas, the Park Plan
builds upon an unprecedented level of related park and recreation facility planning efforts
to preserve river lands, stabilize the Lake Michigan shoreline, coordinate development and
... protect invaluable natural areas, maintain the high quality parks infrastructure, and
program needed recreational facilities...** and also "Be it resolved, that the Milwaukee
County Board of Supervisors approves in principle the SEWRPC... Report No. 132, "A
Park and Open Space Plan for Milwaukee County**. U.S. EPA has also obtained a copy of
this report Map S on p. 25 indicates a bike tour trail along the corridor of the Little
Menomonee River. Map 9 designates the Little Menomonee River from Brown Deer Road
to the confluence with the Menomonee River as a primary environmental corridor. Map
10 also indicates that this same corridor is designated as flood land within Milwaukee
County. Hence, U.S. EPA might conclude that residential development within this corridor
is unlikely. At the current time, this resolution is still in place. Moreover, the change in
risk assessment scenarios is contingent upon securing appropriate deed restrictions.
from Mr. S. Millir
My name is Scott Millir. I just live around here and I agree with using the elevated cleanup
[values] for the different land uses, and the thermal desorption sounds like the better plan of the
two.
Response - U.S. EPA concurs with the comment.
from Mr. D. Michaud
Dave Michaud, a neighbor. I'd like to go on record similar to the gentleman just prior to me.
Response - U.S. EPA concurs with the comment.
from Alderman Tom Nardelli
-------
32
I represent this area and I support the ab[de]sorption method. It looks like it might be a better
one than that which was previously discussed.
Response - U.S. EPA concurs with the comment.
from Mr. C. Theel
I was going to say that perhaps the use of some presumptive techniques could...help shorten the
time that it takes to approve of such methods, along with the...recommended desorption
technique, which seems far superior than the biosluny.
Response - U.S. EPA concurs with the comment.
i
from Mr. J. Brengosz
I would endorse that alternative number 2. My name is Jim Brengosz. I live along the Little
Menomonee River.
Response - U.S. EPA concurs with the comment.
from Mr. S. Brengosz
And I'd like to just comment, too, Steve Brengosz, I live down the street from him, that I think if
the lower cost maybe we could treat more soil or treat the soil better for the same amount of
money that's budgeted, so to speak, for this project.
Response - U.S. EPA concurs with the comment.
from Ms. Rose
My name is Cathy Rose. I would like to conditionally say that the TDU sounds like a better
method, but I have some question about raising from 3.1 parts per million to 47 parts per million
as acceptable. With the deed restrictions, deed restrictions can also be revoked, so 20 years down
the road once...this is forgotten, deed restrictions can be revoked, so I have some hesitations
about that.
Response - U.S. EPA basically concurs with the comment, but would like to note that while
an acceptable cleanup level for CPAHs on land to be used for recreational purposes would
be 49 ppm for direct contact protection and 48 ppm for groundwater protection, those
values would in all likelihood be tempered by the need to also provide protection against
excessive surface soil runoff which would contribute more than the level of 15 ppm
necessary to avoid future river sediment contamination problems. Also, as further
explained in the ROD amendment, U.S. EPA is adopting usage of a groundwater RCL not
-------
33
only for benzo(a)pyrene, which is indeed 48 ppm, but also for fluorene (100 ppm) and
naphthalene (0.4 ppm).
from Mr. McGuigan
I'll just add a clarification. Kerr-McGee is on the hook, I believe, for at least $ 29 million, so to
one of the questions that...was indicated before...it's not taxpayer dollars. I think that if Kerr- -
McGee screwed it up, they should clean it up.
Response - The 1990 ROD provided an estimated present net worth of approximately $ 26
million to perform the work needed to accomplish the ROD objectives. If soils treatment
can be accomplished for less with a change in technology, that figure may be reduced
somewhat. It is true that KMC has entered into a consent decree calling for private
expenditure of remedial design, action, construction and operation efforts necessary to
carry out remedy decision objectives. KMC has also provided financial assurance of its
ability to finance $26 million of work. However, U.S. EPA believes it is more accurate to
say that KMC is obligated by the decree to perform the necessary work, not necessarily to
expend a set amount of money.
from Mr. J. Woida
My name is John Woida, and I think that the recommendation to change the proposal looks very
feasible and less money, less time, greater cleanup, and I think that it's very good that we have
this many people from the community coming that were able to get people interested and
representatives from all the parties that have a stake in resolving this issue.
However, I think that it's still important that we keep our focus on cleaning up the sediments in
the ground water which remain probably the most threatening of the situations to the residents in
the community five miles up and downstream, and particularly since students here at Vincent
High School use the river as a resource in education, we would like to feel safe in using that and
hope that this can be remediated very soon.
Response - U.S. EPA concurs with the speaker's comment concerning proposed change in
soil-related facets of the remedy. U.S. EPA also is pleased with the significant degree of
participation at the meeting, especially taking into account the rather inclement weather
that evening.
As noted in earlier discussion during the meeting, U.S. EPA is aware that sediment
management is an important aspect of the remedy. Given the more liberal change from
utilization of a sediment quality criterion of 3 ppm CPAH compared to the more recently
derived value of 15 ppm, U.S. EPA discussed that dredging technology once dismissed for
sediment management such as wet or dry excavation might indeed be feasible. However,
were dredging as a sediment management tool allowed on a greater scope than is now
-------
34 .
envisioned, some logistics as to its usage must be further developed. One focus of on going
discussions of natural resource trustees is how to consider the integration of site restoration
aspects with remediation. This mainly involves sediment management questions. U.S.
EPA is not a natural resource trustee. U.S. EPA expects to be apprised of discussion
recommendations, and pending outcome would, if necessary, develop a separate proposed
plan to further consider any proposed change to the means of sediment management.
from Ms. L. Dahlke
Lori Dahlke. I think the ab[de]sorption does sound good. -
Response - U.S. EPA concurs with the comment.
i
from Mr. G. Edelstein - WDNR
...We have, for the time being, if you read closely that proposed plan, withheld our formal
concurrence with this plan, but I want to emphasize that we generally do agree with the main
thrust of the plan, the two main thrusts. One, to change the land use exposure assumptions to
those that are being proposed, and the other to substitute low temperature thermal desorption for
slurry biotreatment...
Response - U.S. EPA concurs with the comment.
...In general, we felt that the document was confusing and incomplete. One of the big omissions,
and Russ did talk about this, but it wasn't in the proposed plan, was that soils at the site are going
to have to meet a standard that will be protective of the groundwater, and that will have to be
done either with - by picking the[m] up and treating them or through some method to make sure
that the soils that are left behind do not cause a problem, and that has not really been discussed
clearly in this document...
Response - The plan states that for soil cleanup, cleanup is to be governed by pertinent
standards from the Wisconsin administrative code, and that these cleanup standards cover
both direct contact and groundwater protection. U.S. EPA is aware that some contributors
to the plan felt that even earlier versions were of a complex nature. Consequently, when
further details were sought, U.S. EPA took the position of trying not to "overload" the
reader, and referred the reader to the administrative record for more details. Therefore,
U.S. EPA emphasized more quantitative information in the plan regarding direct contact
soil cleanup goals. The reason is that U.S. EPA felt these would be of more interest to the
citizen living near the site since direct contact with soils presents a more likely pathway for
exposure than groundwater consumption since the aquifer in the vicinity of the site is not
used for such purpose.
...Performance standard cap, e.g., simple soil layer a few inches and some asphalt, but it wasn't
-------
35
discussed in there where it was, how much, and how that would be done. It wasn't really
discussed in any kind of detail about these things we talked about called deed restrictions and
maintenance agreements. Real important if you want to work in the long-term. Wasn't talked
about very much in there...
Response - The plan notes that runoff problems may be avoided either through attaining
certain levels of CPAHs in soils, or by adopting related control measures or performance.
standards. U.S. EPA did not emphasize reliance on performance standards because it is
one tool of many that could be invoked. The control measures to be considered in NR 216
Subchapter III include interim and permanent stabilization practices, structural practices
to divert flow, trapping of sediment in channelized flow, staging construction to limit bare
areas subject to erosion, stabilization of drainage ways, etc. Hence, U.S. EPA did not wish
to limit subsequent design flexibility by overemphasizing performance standard using a
simple soil cover. Indeed, U.S. EPA can foresee there may be instances where insistence on
such performance standard, i.e., a simple soil cover, might conflict with other site
recommendations later on. For example, it b possible that one recommendation from the
natural resource trustees could be to advocate usage of siltation ponds in sediment
management, and then not to abandon such ponds but rather use them as future sources of
stream sinuosity. If a performance standard adopted for site usage gave instruction to fill
in such a pond with soil, that could present a conflict with better usage. Regarding deed
restrictions, U.S. EPA did note in the plan that such restriction would need to be used in
adopting non-residential site usage. The CERCLA statute does not grant significant
enforcement powers to U.S. EPA regarding institutional control measures, a deed
restriction being one such example. Hence, U.S. EPA believes it is sufficient that the plan
called for usage of such restrictions, though greater enforcement powers regarding their
usage may have been granted to other units of government. U.S. EPA agrees that
maintenance arrangements regarding currently paved areas of the site, notably on Union
Pacific property, are important, and U.S. EPA would expect that suitable arrangement
would be one area of discussion between KMC and Union Pacific as they discuss an overall
industrial usage deed restriction.
...There's a little footnote in the plan that talks about using what's called the Superfund waiver or
CERCLA waiver for doing that, and our feeling is that that mechanism is not appropriate for
allowing that unit to be designed without a liner. If the soil's treated right, we don't have a
problem with the design, but that particular provision of the law is not appropriate for allowing
that type of unit...
Response - The primary focus at this point of the plan is to note to the reader that the
original reason for selecting a relatively permeable soil cap instead of the more customary
impermeable cap is no longer valid. U.S. EPA also wishes to inform the plan reader that
what is to replace a permeable soil cover is not necessarily a full-fledged hazardous waste
containment cell. As is further explained in the ROD amendment, the preferred means of
approach in this instance is via CAMU utilization, which provides needed protectiveness
-------
36
for measures noted in ch. NR 636. This appears to offer the best overall approach for
flexibility in dealing with areas to be consolidated, placement of soils after treatment, and
promotion of incentive for enhanced treatment efficiency, etc.
------- |