PB98-964307
EPA 541-R98-170
March 1999
EPA Superfund
Record of Decision:
57th & North Broadway Streets
Wichita, KS
6/5/1998
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RECORD OF DECISION
RIVERVIEW OPERABLE UNIT
57 & N. BROADWAY SITE
SEDGWICK COUNTY, KANSAS
JUNE 1998
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RECORD CF DECISION
DECLARATION
SITE NAME AND LOCATION
57-" &. N. Broadway site - Riverview Operable Unit Wichita, Kansas
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for
che 57'n & N. Broadway site -- Riverview Operable Unit (CU) ,
chosen in accordance with the Comprehensive Environmental
Response, Compensation, and Liability Act of 1980, as amended by
the Superfund Amendments and Reauthorization Act of 1986, and to
the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP). This decision is based on the
administrative record for this site. The State of Kansas concurs
on the selected remedy. J
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances at and from
this site, if not addressed by implementation of the response
action selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare,
or the environment.
DESCRIPTION OF THE SELECTED REMEDY
This operable unit is the first action for the site. This action
will address contaminated ground water in the Riverview area of
the site. The final action for the site will address all other
contamination at the site, including final treatment of the
contaminated ground water for the Riverview OU.
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The major ccmponencs of che selected remedy will include the
following actions:
Provide connection to the Wichita public water supply system
for residences which are currently within the ground water
contaminated plume or are presently threatened by the
contamination in the ground water or in the future have
ground water exceeding drinking water standards. There are
currently 54 residences which meet this criteria. The
connection will include all costs associated with connecting
to the city's distribution lines, setting the meter, running
the line to the residence, connecting the city water to the
residential distribution system, evaluating if a pressure
reduction valve is necessary and if so installing a pressure
reduction valve, permanently severing the private well from
the residential distribution system, and reasonable
restoration of landscaping disturbed by the activity;
Design and install a system of 'in-well strippers' to
prevent the contaminated ground water from spreading beyond
the currently known area of contamination. A single well
will be installed at the site. Upon the evaluation of its
function and performance, a system of wells will be designed
with the intent of preventing the further migration of the
plume; and
A monitoring system will be designed to determine the
effectiveness of the 'in-well strippers' and provide advance
warning in the event the plume's configuration begins to
change. In the event a plume configuration change threatens
additional residents, further evaluation of extending the
actions described in the previous bullets will be taken.
STATUTORY DETERMINATIONS
The selected remedy 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. This remedy utilizes
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permanent solutions and alternative treatment technologies to the
maximum extent practicable, and satisfies the statutory
preference for remedies that employ treatment that reduces
toxicity, mobility, or volume as a principal element.
Because this remedy may result in hazardous substances above
health-based levels remaining onsite, a five-year review will be
conducted to ensure that the remedy continues to provide adequate
protection of human health and th^_environment.
Dennis Grams, P.E.
Regional Administrator
EPA, Region VII
Date
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RECORD OF DECISION
RIVERVIEW OPERABLE UNIT
rTH
57ia & -N. BROADWAY SITE
SEDGWICK COUNTY, KANSAS
JUNE 1998
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TABLE OF CONTENTS
1. 0 SITE NAME, LOCATION, AND DESCRIPTION 1
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 1
3.0 COMMUNITY PARTICIPATION ACTIVITIES 4
4 . 0 SCOPE AND ROLE OF RESPONSE ACTION 4
5 .0 SUMMARY OF SITE CHARACTERISTICS S
5.1 Physical Characteristics 7
-5.2 Nature And Extent of Contamination 8
6.0 CURRENT AND POTENTIAL FUTURE SITE AND RESOURCE USES 9
6.1 Current On-site Land Use 9
6.2 Current Adjacent Land Use 10
6.3 Anticipated Future Use AND Basis for
Assumptions 10
6.4 Current Ground Water Use 10
6.5 Future Ground Water Use and Basis for
Assumptions 10
6.6 Time frame of Projected Future Drinking
Water Use 11
6.7 Current or Potential Future Natural
Resource Use 11
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TABLE CF CONTENTS
7 . 0 SUMMARY OF SITE RISKS 11
7.1 Human Health Risk 12
7.2 Ecological Risks 14
8.0 REMEDIAL ACTION OBJECTIVES 14
8.1 Remedial Action Objectives 14
8.2 Delineation of Areas & Volumes of Contaminated
Ground Water 15
9.0 DESCRIPTION OF ALTERNATIVES 17
*
9.1 Alt. 1: No Action 17
9.2 Alt. 2: Household Treatment & Ground
Water Monitoring 18
9.3 Alt. 3: Household Treatment, In-Situ
Vapor Extraction & Ground Water
Monitoring 20
9.4 Alt. 4: Public Water Supply & Ground
Water Monitoring 21
9.5 Alt. 5: Public Water Supply, In-Situ
Vapor Extraction & Ground Water
Monitoring 22
10.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES ... 22
10.1 Overall Protection of Human Health and the
Environment 27
10.2 Compliance with ARARs 29
10.3 Long Term Effectiveness and Permanence .... 30
10.4 Reduction of Toxicity, Mobility, or Volume
Through Treatment...- 32
ii
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TABLE OF CONTENTS
10.5 Short-term Effectiveness 32
10.6 Implementability 33
10.7 Cost 34
10.7.1 Individual Cost Comparison 34
10.7.2 Cost Sensitivity-of the Alternatives ... 34
10.8 State Acceptance 35
10.9 Community Acceptance 36
11.0 SELECTED REMEDY 37
"11.1 Connection of Residential Properties to
Public Water Supply 37
11.2 In-Situ Vapor Extraction 39
11.3 Ground Water Monitoring 39
11.4 Cost Estimated to be Associated with the
Selected Remedy 40
11.5 Estimated Outcome of Selected Remedy 40
12.0 STATUTORY DETERMINATIONS 42
12.1 Protection of Human Health & the Environment 42
12 .2 Compliance with ARARs 43
12.3 Cost Effectiveness 44
12.4 Utilization of Permanent Solutions and
Alternative Treatment Technologies to the
Maximum Extent Practicable 45
Responsiveness Summary Appendix A
111
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RECORD OF DECISION
DECISION SUMMARY
1.0 SITE NAME, LOCATION AND DESCRIPTION
The Riverview Operable Unit (OU) of the 57"-" & N. Broadway site
is located in the northern portion of the City of Wichita,
Kansas, see Figure i. The actual location of the Riverview OU
lies on a diagonal that runs from the corner of West 50th Street
North and Arkansas Avenue to the southwest to approximately West
46:n Street North and Armstrong Dri^ve, see Figure 2. The
Riverview OU covers portions of five square blocks. A
contaminated ground water plume extends beneath this residential
neighborhood. Nearly all domestic water in the Riverview OU is
obtained from private wells in the contaminated aquifer. To the
south of the site is the Little Arkansas River. No commercial
structures are within the Riverview OU.
^
The apparent source of the ground water contamination is an
extension of the volatile organic contaminant plume originating
near 57th and N. Broadway. Ground water exceeding drinking water
standards for 1,1-dichloroethene (DCE), trichloroethene (TCE),
and vinyl chloride are found at the Riverview OU. These
contaminants are currently and historically found in the main
plume.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
The site is a well established residential neighborhood which has
recently petitioned and been annexed by the City of Wichita. The
local citizens in recognition of the advantages of public water
and fearing that their supply was at risk petitioned the city and
were annexed in 1997.
It is believed that the contamination found in the Riverview OU
is an extension of a volatile organic contaminant ground water
plume originating from near 57th & N. Broadway. The Kansas
Department of Health and Environment (KDHE) completed a site
investigation of the site in 1989. The site investigation
identified several potential sources of contamination of the
variety of compounds which were detected in the ground water.
Further work on the site resulted i-n its being placed on the
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57TH AND NORTH BROADWAY SITE
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RIVERVIEW OPERABLE UNIT
2 ppb Vinyl Chloride Plume
FIGURE 2
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NOT TO SCALE
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National Priorities List (NPL) in 1992. The EPA's investigation
of the 57-" & N. Broadway site did not originally include the
Riverview area.
The EPA performed a removal action from August 1990 until May of
1992 which provided bottled water to the residences and
businesses in the then known affected area of the 57" & N.
Broadway site. That area is now served by Park City's public
water supply system.
The EPA and KDHE facilitated the formation of a local group to
sponsor the installation of a publ.i_c water supply to the area.
This resulted in the construction of a public water supply, owned
by Park City, Kansas, which was capable of providing public water
to the entire affected area. The public water system for the
area was completed in 1992.
There have been several enforcement activities at the 57th & N.
Broadway Superfund site, but none specific to the Riverview OU.
In 1985, the State of Kansas issued an administrative order to
Midland Refining Company (Midland), which required Midland to
develop a plan to investigate ground water contamination around
the Midland facility. Midland complied with the order and
completed a report of the investigation in July 1985.
Three administrative orders have been issued by EPA for the 57th
& N. Broadway site. The first two orders were issued
concurrently on October 4, 1993, along with a notice of liability
to four parties: Coastal Refining and Marketing, Inc.; Farmland
Industries, Inc. (Farmland); Midland Refining Company; and Wilko
Paint, Inc. (Wilko) . The first order was an Emergency
Administrative Order issued along with a Finding of Imminent and
Substantial Endangerment to the Health of Humans under Section
1431 of the Safe Drinking Water Act (SDWA) , to provide a potable
water source to all persons who may be effected by contaminated
ground water from the site. The second order was a draft Consent
Order issued along with a Statement of Work under Sections 104,
122(a) and 122(d)(3) of the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) and Section 1431(a) of
the SDWA, for an investigation of the site.
On October 13, 1993, Coastal Refining and Marketing, Inc., filed
a petition for review with the Tenth Circuit Court of Appeals of
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i he Finding of Imminent: and Substantial Endangerment to the
Health of Persons, and Emergency Administrative Order. A similar
pecition was filed by Wilcc and Farmland on November 10 and
November 12, 1993, respectively. Since several of the issues
involved were of first impression and due to changing policy
considerations, the EPA did not wish to litigate the issues on
appeal. Additionally, because of pre-enforcement review under
the SDWA, the EPA did not want to incur potential long delays
before being able to provide water to those people in need.
Therefore, the SDWA Order was withdrawn by EPA as to all four
parties on December 23, 1993; and the negotiations for actions
under a Consent Order ended.
The third order issued at the site was a Unilateral
Administrative Order issued pursuant to Section 106(a) of CERCLA
to Midland and Wilko on June 6, 1994. Midland and Wilko were
ordered to provide hookups to a public water supply to those
residents within the site, designated by EPA, who wanted to be
hooked "up and had potential exposure to contaminated ground
water. It was further ordered that Midland and Wilko would
perform sampling and analysis of drinking water wells down
gradient of the known contamination and provide hookups to those
people with contaminated water who wished to be added to the
public water supply. Midland and Wilko complied with the order
and all physical work was completed in 1995. In July 1996, the
order was amended to include a payment schedule for reimbursement
of oversight costs. Midland and Wilko reimbursed EPA for
$17,891.30 in oversight costs, and all activities under the order
were completed by February 1997.
In July 1997, the EPA issued general notice letters to six
parties associated with the 57th & N. Broadway Superfund site:
Midland; Wilko; Farmland; Clearwater Truck Company, Inc.; Koch
Industries, Inc.; and Lewis. Williams Jr. The EPA entered tolling
agreements with these six parties in August 1997 to toll the
statute of limitations with regard to the removal action
completed in 1994.
For the action proposed for the Riverview OU, because of the
urgency of the situation, the EPA determined that insufficient
time existed to negotiate a settlement agreeable to EPA and the
identified potentially responsible parties (PRPs). Therefore,
the action discussed in this Record of Decision will be conducted
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as a fund-lead action. Further enforcement options will be
evaluated during the development of the final response actions
for the 57--" & N. Broadway Superfund site.
3.0 COMMUNITY PARTICIPATION ACTIVITIES
A Community Action Group (CAG), intended to serve as a conduit
for information between the community and EPA, was formed early
on in the remedial investigation process of the entire 57th & N.
3roadway site. A number of meetings to exchange information with
the CAG were held in 1996 and 1997. A community-wide meeting was
held on February 11, 1998, to explain EPA's anticipated response
actions and discuss the results of the tap sampling effort.
The City sponsored a meeting which was held in the City Council
Chambers on February 25, 1998. The EPA attended and responded to
questions. On March 2, 1998, a Kansas State Legislative
Subcommittee sponsored a public hearing on the site at which EPA
was requested to be available to answer questions from the
subcommittee and attending citizens.
The announcement of the Proposed Plan was published in two local
papers on April 2, 1998, and the public comment period was
initiated. A public hearing was held on April 16, 1998.
Announcements of the public hearing and copies of the proposed
plan were mailed to those on the EPA mailing list for the site.
Upon the completion of the public comment period on May 1, 1998,
a responsiveness summary addressing all comments and questions
pertaining to the Proposed Plan was prepared and appears as
Appendix 1 to this Record of Decision.
4.0 SCOPE AND ROLE OF OPERABLE UNIT RESPONSE ACTION
The response action selected in this Record of Decision will
address the contamination at the Riverview OU. This response
action involves the provision of an alternate water supply to
residences, the controlling of the ground water contaminant plume
to prevent it from spreading, and monitoring of the ground water
to ensure the measures taken are effective, and to provide early
warning in the event they are not.
This action will address the permanent provision of a safe
alternate drinking water supply to -those who are affected or
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threatened by the contaminated ground water. The ground water
containment/treatment system is to be designed to contain the
plume through treatment and will treat a portion of the plume.
The action undertaken as a result of this ROD will be an interim
action affecting only the Riverview CU. The final action for the
57"-" & N. Broadway site will provide for remediation of the
entire site, including the continuation and possible expansion of
the activities included in this ROD.
5.0 SUMMARY OF SITE CHARACTERISTICS
This section of the Record of Decision presents the results,
conclusions, and recommendations of the Addendum to the Remedial
Investigation Report for the 57th & N. Broadway site developed
for the Riverview OU. In addition, it will report the results of
other investigations that were conducted to identify the location
of the contaminant plume in the Riverview OU. Five specific
sampling events were accomplished to establish the location of
the contaminant plume in the Riverview OU. In addition, a
description of a technical memorandum concerning ground water
modeling to determine the potential for future plume movement is
included. All of these documents are available in the
administrative record for the Riverview OU of the 57th & N.
Broadway site. The specific documents and a summary of their
contents are as follows.
Residential Well Sampling Addendum 1 to Remedial
Investigation Report 57ch & N. Broadway Site Sedqwick
County. Kansas, dated February 1998, prepared for the EPA by
Black St Veatch Special Projects Corporation. This document
outlines the sampling effort conducted to sample 57
residential wells to determine the extent of any
contamination in the ground water. Of the 57 wells sampled,
no contamination was detected in 21 wells. Three compounds,
TCE, 1,1-DCE, and vinyl chloride were detected at
concentrations above the maximum contaminant levels (MCLs).
The report estimated that approximately 25 homes relied on
private ground water wells which contained contamination in
excess of the MCLs.
A memorandum titled Data Transmittal for Activity ft: ATXEF
dated March 18, 1998, is the second source of data. This
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memorandum transmits the validated data from a round of
sampling of 45 homes in the Riverview OU by EPA personnel.
This sampling was conducted to both confirm earlier sampling
and to further define the contaminated ground water's
boundaries. The results of this sampling effort did not
result in any significant change in the boundaries of the
contaminant ground water plume.
The Wichita-Sedgwick County Department of Community Health
conducted additional sampling of 22 residential wells and 14
geoprobe ground water samples. The results were reported to
EPA in a memorandum with the/Subject: Results of Riverview
Sampling, dated March 25, 1998. This document reports the
results of 22 samples taken from domestic wells in the
Riverview vicinity. In addition, at seven geoprobe
locations shallow and deep samples were taken. This
additional information slightly altered the estimated plume
shape in the down gradient direction.
In early March KDHE took a number of samples from
residential wells in an area considered to be to the north
and west of the Riverview OU. These samples were taken in
connection with an ongoing Underground Storage Tank Program
investigation of a facility at 53rd & Arkansas Avenue. The
result of this sampling effort did not provide evidence that
would result in altering the location of the Riverview OU
plume.
In a letter dated April 28, 1998, KDHE transmitted the
results of sampling conducted in recently installed
monitoring wells designed to monitor the plume. The well
locations were established prior to the findings from the
geoprobe sampling; and therefore, the down gradient
monitoring well is still within the plume. The final
monitoring well system to be designed under this Record of
Decision will include a down gradient well beyond the
current plume location. The results provided by KDHE served
to further establish the validity of the estimated plume
location in the Riverview area.
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A Memorandum from 3lack & Veatch Special Projects
Corporation, dated May 4, 1998, contains the report of
modeling efforts to predict the plume's response to the
termination of ground water usage in. the area if all the
residents abandon their private wells and connect to the
city's water system. The report concludes "...
discontinuing use of the individual residential wells is not
expected to have an influence on the groundwater flow
direction or the location of the contaminant plume."
5.1 Physical Characteristics
Ofe-
The 57ch & N. Broadway site is a residential/commercial/
agricultural area covering portions of Park City, unincorporated
Sedgwick County, and the City of Wichita, all in Sedgwick County,
Kansas, as shown on Figure I. The site is located in and
adjacent to Park City and Wichita, Kansas. The Riverview OU
addressed by this Record of Decision is located in the
southwestern portion of the 57t!l & N. Broadway site within the
boundaries of the City of Wichita as shown on Figures 1 and 2 and
is entirely residential.
The geology in the Wichita area consists primarily of sedimentary
rock overlain by alluvium, colluvium, and loess. The 57ch & N.
Broadway site lies within the eastern portion of the Arkansas
River flood plain and terrace complex. The geology of the
Arkansas valley beneath the site consists of two distinct
sediment types: a fine grained zone; and a sandy zone with minor
amounts of gravel. Beneath the topsoil lies a brown to light
brown layer of silty clay and silt approximately 10 to 15 feet
thick. The clayey zone is continuous across the site and has a
low plasticity. The clayey zone grades into a fine to coarse
grained sand zone near the water table. The sand zone may
contain significant amounts of silt in the upper 10 feet of the
sand zone. The sand grades into coarser sand toward the bottom
of the alluvium where the sand may contain some gravel. The
sandy zone is approximately 30 feet thick and lies unconformably
on the blue to gray shale of the Wellington Formation. The shale
is blocky to finely laminated and can appear as a clay where it
is intensely weathered. Based on historical aerial photographs
and information from local residents, an old river channel
existed in the Riverview area prior to residential development.
The old channel was present from the intersection of West 50th
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Street and Arkansas Avenue south across West 49--'1 Street and then
continued southeast to the confluence of Chisholm Creek.
f
However, geologic data were not available to determine whether
the geology beneath the old channel is significantly different
than the rest of the Riverview area.
The alluvial aquifer is the principal aquifer at the site and
consists of unconsolidated Pliocene, Pleistocene, and Holocene
sediments found in the Arkansas River valley. This aquifer is
the principal source of water for the City of Wichita and the
surrounding areas, supplying 70 percent of the city's public
drinking water supply. The portion, of the alluvial aquifer that
supplies the city's water is located northwest of Wichita within
a triangular-shaped area roughly delineated by the cities of
Hutchinson, Newton, and Wichita. The 57-h & N. Broadway site
lies within this triangle. This region of the aquifer is locally
called the Equus Beds Aquifer.
i'
The alluvial aquifer is an unconfined system that flows to the
south-southwest at a gradient of approximately 0.001 feet/feet.
Depth to water table ranges from 8 to 20 feet below ground
surface (bgs). Slug tests were performed on 10 shallow and 10
deep monitoring wells. Because of the high hydraulic
conductivity of the aquifer, the results of the slug testing were
inconclusive; therefore, the hydraulic conductivity data were
estimated using historic pump test data. Results of the pump
test indicate that the hydraulic conductivity at the site ranges
from 50 feet/day to 400 feet/day. The ground water velocity
ranged from 0.51 feet/day to 1.6 feet/day across the site.
No federally listed threatened or endangered wildlife species are
known to inhabit the vicinity of the site.
5.2 Nature and Extent of Contamination
The primary contaminants present in the ground water at the
Riverview OU are the breakdown components of PCE and/or TCE, I,
1-DCE, cis-l,2-DCE, and vinyl chloride. In addition, 1,1-DCA has
also been detected in ground water samples from the area. The
ground water contamination has migrated southwest from the
northeast portion of the 57th & N. Broadway site to the Riverview
OU.
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From the currently available information, it appears that the
ground water contaminant plume in the Riverview residential area
is narrow, approximately 400 feet across at its widest point, and
is approximately located from the intersection of West 50--
Street North and Arkansas Avenue on the north to beyond the
intersection of West 46-r- Street North and Armstrong Drive on the
south as shown on Figure 2. The alignment of the plume follows
the direction of the ground water flow in this area.
The concentrations of the TCE and vinyl chloride in the ground
water indicate the contaminants are in a dissolved form rather
«
than in a pure phase in the ground^ater. Generally, if the
concentration of a compound in ground water is greater than or
equal to 1 percent of the solubility limit of the compound in
water, then a pure phase of the compound may be present in the
ground water. The concentrations of these chemicals in the
ground water were at least two orders of magnitude less than
these solubility limits in the ground water samples collected at
the site.
Table 5-1 provides a list of the contaminants found in the ground
water collected during sampling of the residential wells in the
Riverview area. The EPA compared this information with the
applicable health-based standards and determined that the
selected action was necessary. It also appears from the
available information that the contamination is dissolved in the
ground water and little contamination, if any, exists in the free
or pure phase, as described above. This likely indicates that a
source of continuing contamination has not migrated to the
Riverview area, and the selected remedy should be effective in
addressing the ground water plume. In addition, ground water
monitoring information does not indicate significant ground water
contamination northeast of the Riverview OU. The EPA will
address issues in the area northeast of the Riverview OU in the
final action for the 57th and North Broadway site.
6.0 CURRENT AND POTENTIAL FUTURE SITE AND RESOURCE USES
6.1 Current On Site Land Use.
The Riverview OU consists of a residential neighborhood comprised
of single family dwellings. Within the area considered to be the
affected properties, there are four vacant lots, four properties
reported to already be connected to- the Park City public water
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Table 5-1
Compounds in Groundwater
Contaminant
1 , 1 -Dichloroethane
1,1-Dichloroethene
cis- 1 ,2-Dichloroethene
Trichloroethene
Vinyl chloride
Maximum
Concentration
Detected in the
Riverview Area1
(Mg/L)
99
16
59
6.9
34
MCL2
fog/L)
7
70
5
2
MCLG1
fcg/L)
7
70
0
0
USEPA Region HI
Risk-Based Criteria
for Tap Water*
O'g/L)
810
0044
61
1.6
0019
USEPA Health Advisories3
1-Day
Child"
(/'E/U
2,000
4,000
3,000
10-Day
Child7
O'R/L)
1,000
2,000
3,000
Longer-Term
Child*
(MB/L)
1,000
2,000
10
Longer-Term
Adult11
0
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system, and 54 addressed lots assumed to have inhabitable
residences which currently utilize private wells as the source
for domestic water.
6.2 Current Adjacent Land Use
The area immediately to the north and west of the Riverview OU
currently consists of additional single residential homes. The
area to the south of the Riverview OU is predominantly
agricultural and open space adjacent to the Little Arkansas
River. There are a few residences in this area as well. To the
west of the Riverview OU is a small number of commercial
businesses, farm land, and residences. Further to the east is
the Chisholm Creek Flood way.
6.3 Anticipated Future Land Use
The Riverview OU and adjacent area is a well established
residential neighborhood with a few small businesses, religious
institutions, and farming interests scattered around the edges.
It is not anticipated that significant changes will be made in
the land use of this area in the near future. With the
availability of city water, there is some additional opportunity
for additional business or commercial interests to locate in the
area, especially where there are currently open spaces. It is
unlikely that any of the isolated vacant lots will be developed
for purposes other than residential.
6.4 Current Ground Water Use
The ground water is currently the sole source of domestic water
for the majority of the Riverview OU. Homes and businesses in
the area have relied upon private wells to supply ground water as
the only source of water. The Park City water system currently
supplies a small number of homes in the general area with
domestic water. In addition, ground water is used for watering,
filling swimming pools, and other uses usually associated with
activities taking place in residential neighborhoods.
6.5 Potential Future Ground Water Use
It could be anticipated that even with the availability of public
water supplies the ground water wil-1 be used as a source of
10
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domestic water in many homes. The contaminant plume is
relatively small, and there is a supply of water available to
those who are not affected by the volatile organic contamination.
There is a concern with the quality of the ground water and the
general satisfaction of the residents in the quality of the
ground water seems to have diminished over the last several
years. Therefore, it is not known how many residents will take
advantage of the new public water system and how many will
continue to use their private wells. There seems to be a general
consensus that some of those who elect to connect to public water
will retain the use of their private wells for lawn and garden
use. Another factor that may or may not affect the future use of
ground water is the unavailability of sanitary sewers in the
area. The entire Riverview OU and the surrounding area use
septic tanks for domestic sewage treatment. This may impact the
quality of the ground water.
6.6 Time frame of Projected Future Drinking Water Use
This action is not intended to restore the aquifer in the
Riverview OU. There will be some treatment that takes place in
the containment of the plume, but no estimate is possible at this
time of the extent of that treatment and the time it will take
for that treatment or natural attenuation to restore the aquifer.
The current health threat to the Riverview OU residents will be
eliminated by supplying an alternative water supply. It is
assumed that not every residence in the vicinity of the Riverview.
OU will take advantage of the availability of the public water
supply and that ground water will continue to be used for
domestic supplies. Many of those residents that do take
advantage of the availability of the public water supply will
likely continue to use ground water for some purpose.
6.7 Current or Potential Future Natural Resource Use
Other than ground water, gardening, and small scale farming there
is no present or likely future use anticipated of natural
resources in the Riverview OU.
7.0 SUMMARY OF SITE RISKS
The sole risk in the Riverview OU is to the health of the
residents who are currently using ground water as their domestic
11
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water supply. Volatile organic contaminants at concentrations
above the MCLs have been found in the wells of the residents and
additional ground water monitoring has delineated a plume of
contamination which contains vinyl chloride in excess of Che MCL.
The area of concern has been defined as that which is currently
known or suspected to have contaminated ground water above the
MCLs.
7.1 Human Health Risk
Three contaminants detected in the ground water were found to
exceed MCLs. They are 1,1-DCE, TCJ^ and vinyl chloride. Of the
three, vinyl chloride presents the greatest risk and is the most
prevalent. No well tested exceeded the MCL for any contaminant
that did not also exceed the MCL for vinyl chloride. In some
wells the only contaminant that exceeded the MCL was vinyl
chloride. Based upon these findings, vinyl chloride became the
main indicator chemical, although analysis of the other
contaminants was considered.
Vinyl chloride is a colorless gas with a mild, sweet odor. It is
a man-made chemical that does not occur naturally in the
environment. Most of the vinyl chloride produced in the United
States is used to make polyvinyl chloride (PVC). The most likely
way that vinyl chloride can enter your body is if you breathe air
containing it. This path of exposure is of concern for persons
employed in vinyl chloride manufacturing, for people living in
communities where vinyl chloride plants are located, for
individuals living near hazardous waste disposal sites and, to a
lesser degree, those using water contaminated with vinyl
chloride. Vinyl chloride can also enter your body if you eat
food or drink water containing it. Passage of vinyl chloride
through the skin is not likely to be an important pathway.
An increased risk of developing cancer of the liver and possibly
several other tissues has been linked with breathing air in
factories containing vinyl chloride. The U.S. Department of
Health and Human Services has determined that vinyl chloride is a
known carcinogen.
Some of the health effects observed in humans have also been seen
in laboratory animals. Effects on the nervous system of animals
have occurred after short-term exposure to very high levels of
12
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vinyl chloride in air. Effects on the liver developed in animals
after short-term exposure to high levels and after longer-term
exposure to lower levels of vinyl chloride. Kidney effects also
occurred after exposure to high levels. Laboratory animals
developed cancer in several tissues after eating food or
breathing air that contained vinyl chloride.
Vinyl chloride can be measured in urine and body tissues, but the
tests cannot be used to determine at what levels of vinyl
chloride an individual may have been exposed. Measuring the
amount of the major breakdown product of vinyl chloride in the
urine may give some indication of /recent exposure; however,
people differ in the quantity of excretion of the breakdown
produce. Neither of these tests is routinely available at your
doctor's office. The laboratory tests commonly used by doctors
to evaluate liver damage and liver function are usually not
helpful for determining if liver damage from vinyl chloride
exposure has occurred.
The EPA used available data in animals to estimate that breathing
air containing 1 part per million '(ppm) vinyl chloride every day
for 70 years may place as many as 11 percent of a population at
risk of developing cancer. Eating food containing 1 ppm vinyl
chloride every day for 70 years may place as many as 6.44 percent
at risk of developing cancer. Similarly, drinking water
containing 1 ppm vinyl chloride every day for 70 years may place
as many as 6.57 percent at risk of developing cancer. It should
be noted that these risk values are plausible upper-limit
estimates based on information obtained from animal studies.
Actual risk levels are unlikely to be higher and may be lower.
The Clean Water Act requires that community drinking water
systems that regularly serve the same 25 persons for at least
eight months of the year must limit vinyl chloride in the
drinking water to 2 ug/L (2 parts per billion [ppb]) starting
January 9, 1989. This is the Maximum Contaminant Level (MCL) for
vinyl chloride. This is also the action level for Superfund
action at a site where contaminated water is being consumed by
the public from any source. Studies have indicated that the
exposure to 2 ppb vinyl chloride in drinking water for a period
of 70 years may increase the likelihood of developing cancer by 1
in a million.
13
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At this time, the exposure of the population ^o ground water
above MCLs was sufficient to establish risk. The actions
proposed in this ROD will remove the population Known to be at
risk from contact with the contaminated ground water. It is
anticipated chat the containment measures will prevent future
migration of the plume from the Riverview area.
7.2 Ecological Risks
No known ecological risks exist in the Riverview OU.
8.0 REMEDIAL ACTION OBJECTIVES
This section presents the remedial action objectives developed to
address the ground water contamination in the Riverview OU of the
57" & N. Broadway site. This section also includes a discussion
of the delineation of the area and volume of contaminated ground
water.
*
8.1 Remedial Action Objectives
CERCLA, as amended by Section 121(b) of SARA, 42 USC §9621,
requires selection of remedial actions to attain a degree of
cleanup that ensures protection of human health and the
environment, are cost effective, and use permanent solutions and
alternative treatment technologies or resource technologies to
the maximum extent practicable.
To satisfy CERCLA requirements, remedial actions objectives were
developed for the Riverview OU. Remedial action objectives were
used to develop remedial action alternatives. Remedial action
objectives developed for contaminated ground water include the
following:
Prevent ingestion, inhalation, or direct contact with
ground water having vinyl chloride, TCE, or 1,1-DCE at
concentrations in excess of current federal and state
regulatory drinking water standards. Current
regulatory drinking water standards include MCLs, which
are maximum permissible levels as established by the
Safe Drinking Water Act (SDWA), [40 CFR Part 141] for a
contaminant in water that is delivered to any user of a
public water system; and
14
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Prevent further migration of contaminants to prevent
degradation of natural resources and the potential
contamination of additional water supply wells.
8.2 Delineation of Areas and Volumes of Contaminated Ground
Water
Information concerning the nature and extent of contamination in
ground water was used to estimate the volume of contaminated
ground water that will need to be remediated in the Riverview OU
of the 57th & N. Broadway site. Ground water that is contam-
inated at concentrations exceeding^those proposed remedial
actions (i.e., MCLs) for the Riverview OU will be considered the
portion of the contaminant plume that will require response
actions. The MCLs for the contaminants of concern are presented
in Table 8-1 on page 14 of this document.
The area of ground water containing vinyl chloride above MCLs is
the largest and encompasses the areas of the remaining
contaminants exceeding MCLs. Therefore, vinyl chloride was the
contaminant used to estimate the volume of contaminated ground
water in the Riverview OU of the site. The MCL for vinyl
chloride is 2 ,ug/L. The areal extent of contaminated ground
water in the Riverview OU requiring remediation is shown on
Figure 2. Based on this information, the areal extent of
contamination is estimated to be approximately 650,000 square
feet (ft2) . For estimation purposes, the areal extent of vinyl
chloride will be considered to be evenly spread vertically in the
aquifer. The approximate saturated thickness of the aquifer
ranges from 15 to 35 feet. The approximate total contaminated
ground water plume in the Riverview OU will be 24.5 million
gallons, assuming an average saturated thickness of 25 feet and
an effective pore volume of 20 percent.
15
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Table 8-1
Chemical-Specific ARARs and Other Criteria and Standards, or
Guidance to be Considered for Compounds in Groundwater
Contaminant
1,1-Dichloroelhanc
1,1-Dichloroelhene
cts- I ,2-Dichloroethcne
Trichloroethene
Vinyl chloride
Maximum
Conccnlrulion
Detected in the
Riverview Area1
(/ u^er ola pul>lic t^.ilei -,\ r-uiu
3 Maximum cunlaiiiinanl level goal (MCI Ci). 40 C'lK I'art Ml. a non-enloreeable e»neenlralion of a di inking \\aler ennlaininanl thai is proleelive n I adverse human health ille*.! .UK
alkiu an adequate margin of safely.
4 USl-l'A Keguin 111 Kisk-UasedC'mieenlriilinn. bused on u Ixld' eiiteiiHigenii; risk or noneareinogenie lui/;»d nules i>n I 0. Oelubei ll*''7
5 IISIil'A Drinking Waler Kcgulalions and Health Advisories. Ol Ike of Water. lil'A 822-II-V6-D02. October IWh
6 I lie concentration ol'a cliemical in drinking water that is not expected to cause any adverse mmcarcinogcnic elleels lor n|> to 5 consecutive davs ol 'exposure
7 The concentration ol'a chemical in drinking water that is no) expected to cause any adverse noncarcinogenic elleels lor up (o 14 consecutive days ofexpostire
8 Hie concentration ol a chemical in drinking water thai is no! expected to cause any adverse nonearcinogenic elleels lor up to approximate!) 7 consecutive ila>s ol cxpusme
9 'I lie concentration of a chemical in drinking water that is mil expected to cause any adverse noncarciiiogenic elleels over a lifetime ol exposme
16
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3.0 DESCRIPTION OF ALTERNATIVES
This section presents the remedial action alternatives developed
to address the ground water contamination in the Riverview OU of
the 57-h & N. Broadway site. These alternatives have been
developed to determine the appropriate interim remedial action
necessary for the Riverview OU. Five remedial action
alternatives have been developed to address the ground water
contamination in the Riverview OU. Since this is an interim
action, it is anticipated that the remedial alternative for the
entire 57th & N. Broadway site will encompass and take over any
actions remaining for the Riverview OU. Therefore, it is assumed
Os
that these interim actions will function for no more than three
years before being taken over by the remedial alternative for the
entire 57th & N. Broadway site. The five alternatives for the
Riverview OU include:
No action;
Household treatment with ground water monitoring;
Household treatment with in-situ vapor extraction, for
plume control, and monitoring;
Connection to a public water supply with ground water
monitoring; and
Connection to a public water supply with in-situ vapor
extraction and monitoring.
Detailed discussions of these ground water alternatives are
presented in this section.
9.1 Alternative 1 - No Action
Alternative 1 will not involve any remedial actions, and the site
will remain in its present condition. This alternative, required
by CERCLA and the NCP, is a baseline alternative against which
the effectiveness of the other alternatives can be compared.
Under the no action alternative, the site is left "as is"; and no
funds will be expended for monitoring, control, or cleanup of the
contaminated ground water. However, a five-year review of the
site will be required under CERCLA; thus, funds will be expended
to conduct the review. Since any five-year review will take
place after the maximum three-year life of this interim action,
17
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it will come during the period cf rime that the remedy for the
entire 57-" & N. Broadway site is active and will not be
considered under this action.
5.2 Alternative 2 - Household Treatment with Ground Water
Monitoring
Under Alternative 2, household treatment systems will be
installed and maintained in each affected, or potentially
affected, residence and a ground water monitoring program will be
implemented. The treatment systems will be leased or purchased
and installed in the home plumbinc^_system before the plumbing
system branches throughout the house. The treatment system will
consist of a household granular activated carbon (GAC) unit. The
GAC treatment units are packaged, commercially available units.
Evaluations will be made to determine the appropriate maintenance
interval for each filter. This alternative will also include
ground water monitoring of the contaminant concentrations in the
ground "water to monitor the levels of VOCs present and assess the
migration of the contaminants.
The installation and maintenance of the GAC units will be
performed by the company supplying the units. Installation of
the units will require minor re-plumbing to install the units in
the water line where the water from the well enters the household
plumbing system. For costing purposes, it is assumed that
maintenance of the unit will be required every six months and
will consist of replacing the carbon filter in the GAC unit.
Actual maintenance will be performed based upon the actual
performance of the filter.
The ground water monitoring program will consist of sampling the
ground water in the Riverview area four times a year until such a
time that the final remedy for the entire 57-h & N. Broadway site
provides for a ground water monitoring program, or treatment,
which is assumed to be three years. Ground water monitoring is a
component of all of the alternatives except no action. It is
anticipated that an appropriate ground water monitoring network
consisting of at least five wells will be installed prior to the
implementation of any of the remedies discussed in this document;
therefore, the establishment of such a network and its design or
cost is not specifically covered within this document. The
monitoring effort will include analysis of the following
18
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parameters Co assess the concentration cf contaminants in the
ground water and the effectiveness of the natural attenuation:
Volatile organic compounds; Sulfate;
Methane, ethane, ether.2; Sulfide;
Dissolved oxygen; Chloride;
Nitrate; Bromide,-
Iron (II); Conductivity;
Oxidation/reduction potential, Temperature,- and
pH; Total organic carbon.
ot*~
The monitoring effort will consist of collecting ground water
samples from existing monitoring wells in or near the
Riverview OU. The wells to be monitored will include both
upgradient and downgradient monitoring wells, as well as
monitoring wells located within the area of ground water
contamination. Ground water samples will be collected from
each of the wells for the parameters listed above. A
detailed sampling and quality assurance plan will be used to
specify the sample location, sample frequency, laboratory
analyses, and sampling procedures. Five wells are being used
for cost estimating purposes.
It is not anticipated that the ground water plume will
naturally attenuate within the expected duration of this
activity, three years. Based on the ground water modeling
effort conducted as part of the remedial investigation, it is
estimated that the use of the GAC units will be required for
20 years. Therefore, it is expected that this alternative
will be either replaced by remedial actions selected for the
entire 57ch & N. Broadway site or taken over as part of that
effort.
19
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9.3 Alternative 3 - Household Treatment and In-situ Vapor
Extraction
This alternative is the same as Alternative 2 except that in
addition to installing household treatment systems and
implementing ground water monitoring, the ground water
contamination within the Riverview OU will be contained and
treated using in-situ vapor extraction. The in-situ
treatment of the contaminated ground water will be
accomplished through the use of in-situ vapor extraction
wells. The in-situ vapor extraction wells will be screened
in the alluvial aquifer. Air will be injected below the
water table into the well by use of a blower. The injected
air increases the pressure in the well that draws ground
water from the lower portion of the well and traps air in
that water. The water is allowed to rise until it meets a
packer where the volatile organic contaminants are released.
A vacuum blower is used to apply a vacuum on the upper well
casing to remove the organic vapors from the well. The in-
situ vapor extraction process is shown on Figure 3.
In-situ vapor extraction wells will be placed to stop
further migration and partially treat the ground water. The
final number and locations of the wells will be determined
during remedial design. It is anticipated that prior to the
initiation of the remedy, additional characterization of the
plume and aquifer constituents will be completed. This will
include the completion of a monitoring system for the
Riverview OU plume. The remedial design will also include
the installation of a pilot well which will be used to
determine the effectiveness of the technology and assist in
determining the number and placement of the remaining wells
required to contain the plume.
20
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3LCHE3
3 VACUUM 8LOHER
STRIPPED VOC
VAPORS
) UPPER RECHARGE SCREEN
CLEAN HATER
GROUND
RECIRCULATION
ZONE
SPARGING DIFFUSES
VOC CONTAMINATED
GROUND HATER
LOHER
EXTRACTION SCREEN
20-a
FIGURE 3
ALTERNATIVE 5
IN SITU VAPOR
EXTRACTION SYSTEM
-------
No treatment of the off-gas is expected to be necessary, due
to the lew levels cf contaminant vapor being extracted and
che wells being located outside. The emissions generated
will be much less than will require treatment. The air
emissions are not considered to present a human health
threat. In addition, the final emission rates which will be
determined for the wells are expected to be well below the
Kansas Air Pollution Controls and Regulations emission limits
for total VOCs. A pilot test will ensure the effectiveness
of the technique. If the pilot fails, other technologies
will be considered.
Ground water monitoring using existing monitoring wells will
be performed under this alternative to verify hydraulic
performance and to verify the active restoration of the
aquifer. Ground water monitoring will be performed for a
period of no more than three years, under the Riverview OU.
The remedial alternative selected for the entire 57th & N.
Broadway site will take over the responsibility for ground
water monitoring. Ground water monitoring will be the same
as described in Alternative 2.
9.4 Alternative 4 - Provide Public Water Supply with Ground
Water Monitoring
Under this alternative, the affected Riverview residences
will be connected to a public water supply system. The City
of Wichita is currently installing public water supply lines
through the area. It is assumed that the installation of the
water distribution system will be completed by the City of
Wichita and that the connection will include installing water
lines from the house to the city's water main and payment of
the city's connection fees. It is estimated that each
connection will cost between $2,000 and $3,500. This
21
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alternative will also include implementing a ground water
monitoring program. The ground water monitoring program will
be the same as that described for Alternative 2.
This alternative will include minimal re-plumbing of the
household water system to tie into the public water supply
system and disconnect the household plumbing from the
residential well. In addition, each residence will be
inspected by the plumber to determine the necessity of
installing a pressure reduction \gtlve and, if necessary, that
valve will be installed.
9.5 Alternative 5 - Provide Public Water Supply and In-situ
Vapor Extraction
«
This alternative is the same as Alternative 3 .except that the
affected residences will be connected to the public water
supply system, as described in Alternative 4, instead of
using GAG treatment units for the duration of the
remediation. The containment of the contaminated ground
water will be accomplished through the use of in-situ vapor
extraction wells as described in Alternative 3.
10.0 Comparative Analysis of Alternatives
In this section, the remedial alternatives are evaluated
against certain criteria so that the advantages and
disadvantages associated with each clean up option for the
Riverview OU of the 57ch & N. Broadway site are clearly
understood. Each alternative is evaluated against the NCP-
required criteria.
The remedial alternative evaluation criteria have evolved as
a result of statutory requirements that must be addressed in
22
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Che Record of Decision. CERCLA requires that remedial
actions meet the following criteria:
3e protective cf human health and the environment;
Attain applicable or relevant and appropriate
requirements (ARARs) or provide grounds for invoking a
waiver;
Be cost-effective;
Use permanent solutions and alternative treatment
technologies or resource r^govery technologies to the
maximum extent practicable; and
Satisfy the preference for treatment that reduces
toxicity, mobility, or volume as a principal element or
provide an explanation in the ROD of why it does not.
The NCP and the "Interim Final Guidance for Conducting
Remedial Investigations and Feasibility Studies Under CERCLA"
provide nine evaluation criteria to address the CERCLA
statutory requirements considerations:
Overall protection of human health and the environment;
Compliance with ARARs;
Long-term effectiveness and permanence;
Reduction of toxicity, mobility, or volume through
treatment;
o Short-term effectiveness;
Implementability;
Cost;
« State acceptance; and
« Community acceptance.
Table 10-1 describes the evaluation factors for each of
the nine criteria. In this section, each individual
alternative is evaluated against the nine criteria.
23
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The following discussion presents ~he primary components of
each of the nine criteria that are used to complete the
detailed evaluation of alternatives. The first two criteria,
overall protection of human health and the environment and
compliance with ARARs, are considered threshold criteria.
These criteria must be met for an alternative to be
considered a remedy for a site. The next five criteria are
considered balancing criteria. Tradeoffs are made between
the alternatives with respect to the balancing criteria;
however, specific weighing factoaat-are not used. State
acceptance and community acceptance are considered modifying
criteria, and are used to assist in identifying and/or
modifying the preferred alternative after the public comment
period.
Overall Protection of Human Health and the Environment
This criterion provides an overall assessment of
whether each alternative will adequately protect human
health and the environment. The overall protectiveness
focuses on whether an alternative will achieve adequate
protection and how site risks will be eliminated,
reduced, or controlled through treatment, engineering,
or institutional controls. This criterion is
considered a threshold criterion; that is, overall
protection must be provided for an alternative to be
considered as a remedy for the site.
Compliance with ARARs
This criterion, also a threshold criterion, assesses
whether an alternative will meet all federal and state
ARARs for the site, including action-specific ARARs.
ARARs were identified for the site in the Technical
Memorandum on Identification of Applicable or Relevant
and Appropriate Requirements which was produced in
24
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preparation for the 57" & N. Broadway site remedial
investigation/feasibility study.
Long-Term Effectiveness and Permanence
This balancing criterion assesses the residual risk
that will remain at the site after the remedial action
objectives are achieved. The extent and effectiveness
of the controls needed to manage any treatment
residuals or untreated medi;*-are assessed by
qualitatively determining the magnitude of any residual
risk remaining at the site at the conclusion of the
remedial activities. Also, the adequacy and
reliability of the controls that are used to manage any
treatment residuals or monitor untreated media
remaining at the site are assessed.
Reduction of Toxicity. Mobility, or Volume Through
Treatment
This balancing criterion assesses the degree to which
site media will be treated to permanently and
significantly reduce the toxicity, mobility, or volume
of site contaminants. This is accomplished by
analyzing the destruction of toxic contaminants, the
reduction of the total mass of toxic contaminants, the
irreversible reduction in contaminant mobility, or the
reduction in total volume of contaminated material.
Short-Term Effectiveness
This balancing criterion addresses the effects of an
alternative on site surroundings during the
construction and implementation phases of the remedial
action, before remedial action objectives are achieved.
These effects include consideration of the protection
25
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of workers and the community during remedial action
implementation, environmental impacts that night result
from construction or implementation, and the length of
time until the remedial action objectives are achieved.
Implementability
This balancing criterion addresses the technical and
administrative feasibility of implementing an
alternative and the availability of various services
and materials required durijag implementation.
Technical feasibility encompasses the technical
difficulties and unknowns associated with the
alternative, the reliability of the technologies, the
ease of undertaking additional remedial actions if
necessary, and monitoring requirements. Administrative
feasibility includes the activities required for
coordination with other offices and agencies.
Availability of services and materials includes the
availability of necessary equipment and specialists,
the ability to obtain competitive bids, and the
availability of prospective technologies.
Cost
The cost criterion involves an evaluation of the
capital costs, the annual operation and maintenance
(O&M) costs, and a present worth analysis. The cost
estimates are estimates, which are defined as
approximate estimates made without detailed engineering
data. It is normally expected that an estimate of this
type will be accurate to +50 percent and -30 percent.
The actual costs of the project will depend on the
final scope of the remedial action, the schedule of
implementation, actual labor and material costs at the
time of implementation, competitive market conditions,
26
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and ccher variable factors chat may impact the project
costs.
State Acceptance
Modifications to the proposed plan may be made as a
result of consultation with the state based upon the
state's roll as support agency for the site. Every
effort is made to include the state as a full partner.
Community Acceptance
ic
Comments from the community received during the publ
comment period-may result in modification of the remedy
to address specific community concerns.
10.1 Overall Protection of Human Health and the Environment
Alternative 1 will not protect human health and the
environment from the contaminants in the ground water.
Because no actions will occur under Alternative 1, the ground
water contaminants may continue to migrate and contaminate
additional private water supply wells and result in a larger
contaminant plume.
Although no remediation occurs under Alternatives 2 or 4,
these alternatives will be more protective than Alternative
1. Alternatives 2 and 4 will provide protection of the
public health by using household GAC treatment units and/or
connecting the affected residences to the public water supply
system. Alternatives 2 and 4 will provide continuing
monitoring of the contaminant plume to determine the plume's
migration route and to determine if natural attenuation is
occurring. Some natural attenuation will occur under
27
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Table 10-1
Factors for Analysis of Alternatives
Oxeinll
Protection
Him alternative
pm\ iik-s human
health and
cnviinmncHlal
piolcclion
('onipliiiitce
with Applicable 01
Relevant ^1 nl
Appropriate
Requirements
(ARARs)
Compliance \vilh
coiilaniiiianl -
spccilic ARAKs
Compliance \\ilh
action - specific
AKAKs
Compliance vvilh
location - spccilic
ARARs
Compliance \\ilh
lii-hc-consitlcrcd
(ini's)
(apprnprialc
crilctin. aJvisorics.
and gniilancc)
l.img- Icrin
lillcclivcncss
MatinilnJc ul
residual risk
Long-term conlruls
. -4
Kcdiicliim til
l(l\lcil\.
Miihilit). in
volume
Itcalincnl process
used and materials
Healed
Aninunl ol
ha/ardous
materials dcslrn^ed
in Healed
Decree ul c\pecled
rediiclions in
lii\icil\. ninliilil).
nr volume
Device lo uliicli
licalmeiil is
irreversible
1 vpe and qiiiinlily
ul residuals
rcinainiiif! alter
lieatnicnl
Shon-'I'erm
l-ITeclivcness
I'rulcclion ol"
conirminily and
workers during
remedial actions
1 n\ irunmcnlal
Inipacls
lime nnlil remedial
acliini ohjeclives
arc achieved
Implcmcnlahilily
leehnical
leasihilily
Adniinislralive
feasibility
Avdilabilih ol
necessary scrv ices
and materials
Cos!
Direct capital costs
Indirect capital
eosis
Operating and
maintenance costs
Present worth cost
Stale Acceptance
Aspects of the
alternative the Stale
ol Kansas supports
Aspects of the
alternative the Stale
ol Kansas has
reservations about
IJcmciils ol 'the
alternative (lie State
ul Kansas strungl)
opposes
('oniniunily
Acceptance
Aspects ol the
allcrnalive the
community
supports
Aspects ol the
alternative the
ciuniminil) lias
reservations about
lilemenls ol the
allei native the
communilv
slKingl) opposes
28
-------
Table 10-2
Comparative Analysis of Alternatives
Evaluat ion
Criteria
Overall
Protect ion
Compl iance
with
Applicable or
Relevant and
Appropriate
Requi lements
(ARARs)
Alternative 1
No Action
This alternative
will not provide
protection of huijan
health or the ' "^
environment .
No remedial action
objectives will be
satisf ied .
Present groundwater
quality does not
meet chemical -
specific ARARs.
Alternative 2
Household Treatment
and Ground Water
Monitoring
Protective by
eliminating use of
untreated
contaminated ground
water as a potable
water supply. Both
remedial action
objectives will be
met .
This alternative
will comply with all
Fedeial t. State
ARARs, if natural
attenuation occuis.
Compliance with
chemical -speci f ic
ARARs can only be
determined after
several sampling
rounds .
Alternative 3
Household Treatment
and In Situ Vapor
Extraction
Protective by
eliminating use of
contaminated ground
water as a potable
water supply and
actively restoring
the ground water
quality. Both
remedial action
objectives are be
met .
This alternative
will comply with all
Federal and State
ARARs.
Alternative 4
Public Water Supply
and Ground Water
Monitoring
Protective by
eliminating use of
untreated
contaminated ground
water as a potable
water supply. Both
remedial action
objectives will be
met .
This alternative
will comply with
all Federal and
State ARARs, if
natural attenuation
occurs. Compliance
with chemical-
specific ARARs can
only be determined
after several
sampling rounds.
Alternative 5
Public Water Supply
and In Situ Vapor
Extraction
Protective by
eliminating use of
contaminated ground
water as a potable
water supply and
actively restoring
the ground water
quality. Both
remedial action
objectives will be
met .
This alternative
will comply with
all Federal and
State ARARs.
28-a
-------
Evaluation
Criteria
Long -Term
Ef fecti veness
Reduction of
Toxicity,
Mobility, or
volume
Short -Term
Ef fecti veness
Alternative 1
No Action
This alternative
does not provide
active reduction in
long-term risk. No
long-term controls.
Unknown if reduction
of contaminat ionl
will be achieved^
No mechanisms to
monitor
contamination
levels .
Because no actions
will be conducted.
there will be no
increase in the
short-term lisks to
the community or
environment .
Alternative 2
Household Treatment
and Ground Water
Monitoring
Higher long-term
risk with
contaminated ground
water remaining in
aquifer than in
Alternatives 3 or 5.
Risk due to the
plume not contained
or actively
remediated .
Unknown if reduction
of contamination
will be achieved
without additional
monitoring data.
Several years of
monitoring may be
necessary until a
reduction is
determined .
Risk to community
and workers will be
low. The time to
reach cleanup goals
will be similar to
Alternative 4
because no active
treatment of the
ground water is
included.
Alternative 3
Household Treatment
and In Situ Vapor
Extraction
Minimal long-term
risk with treated
ground water.
Minimal long-term
risk with remaining
contaminated ground
water because the
aquifer will be
actively remediated.
Reduction through in
situ treatment. No
treatment residuals
generated. Meets
statutory preference
for treatment as a
principal element.
Risk to community
and workers will be
low as long as the
proper measures are
taken .
Alternative 4
Public Water Supply
and Ground Water
Monitoring
Higher long-term
risk with
contaminated ground
water remaining in
aquifer than in
Alternatives 3
or 5 . Risk due to
the plume not being
contained or
actively
remediated .
Unknown if
reduction of
contamination will
be achieved without
additional
monitoring data.
Several years of
monitoring may be
necessary until a
reduction is
determined.
Risk to community
and workers will be
low. The time to
reach cleanup goals
will be similar to
Alternative 2
because no active
treatment of the
ground water is
included.
Alternative 5
Public Water Supply
and In Situ Vapor
Extraction
Minimal long-term
risk with treated
ground water.
Minimal long-term
risk with remaining
contaminated ground
water because the
aqui f er will be
actively
remediated.
Reduction through
in situ treatment.
No treatment
residuals
generated. Meets
statutory
preference for
treatment as a
principal elenent.
Risk to community
and workers will be
low as long as the
proper measures are
taken .
28-b
-------
Evaluation
Criteria
Implementabi 1 i
'Y
Cost Range
(Total Present
Wot th)
State
Acceptance
Communi t.y
acceptance
Alternative 1
No Action
An evaluation of
implementabi li t y
during remediation
is not applicable.
So
i
-5
No state acceptance
No community
acceptance
Alternative 2
Household Treatment
and Ground Water
Monitoring
Technical ly
feasible.
Administratively
feasible. Mill be
the easiest of the
alternatives to
implement .
lease- $308,250 -
$392,250; buy-
$245,250 - $313,500
No state acceptance
No community
acceptance
Alternative 3
Household Treatment
and In Situ Vapor
Extraction
Technically
feasible. This is
an innovative
technology, few
contractors are
available. Thus,
alternative may be
more difficult to
implement than
others. Feasible
administratively.
lease-$48l, 110 -
$625,590
buy- $430,710 -
$562,590
No state acceptance
No community
acceptance
Alternative 4
Public Water Supply
and Ground Water
Monitoring
Technically
feasible. will be
slightly mote
difficult to
implement than
Alternative 2.
Administrat ively
feasible .
$219,000 - $366,750
No state acceptance
Some community
acceptance
depending upon the
area water will be
provided.
Alternative 5
Public Water Supply
and In Situ Vapor
Extraction
Technically
feasible. This is
an innovative
technology, few
contractors are
available. Thus,
alternative may be
more difficult to
implement than
others. Feasible
administratively.
$451,710 - $661,690
State concurs this
remedy is optimal
The community
accepts this
remedy, however
thinks assistance
should cover
property
assessments and
cover a broader
area .
28-c
-------
Alternatives 2 and 4. However, if concentrations do not
decrease, the potential for migration cf ground water
contamination is also possible.
Alternatives 3 and 5 will be most protective of human health
and the environment because ground water with contaminant
concentrations greater than cleanup levels will be contained.
The remedial objectives will be reached earlier with
Alternatives 3 and 5 than with Alternatives 2 or 4. The
technology used in Alternatives 3 and 5 (in-situ vapor
extraction) is effective in the removal of VOCs from ground
water.
Besides the contamination that remains within the contained
plume, no short-term risks will be expected in each of the
alternatives. Although the contaminants will be released
into the air during treatment in Alternatives 3 and 5, the
potential for cross-media contamination is very low because
the emission concentrations will not be expected to present a
risk to human health and will conform to allowable emissions
rates set forth in the applicable regulations.
The long-term reliability of Alternative 5 is greater than
Alternative 3 because of the use of water from the public
water supply system rather than household treatment of the
private well water.
10.2 Compliance with ARARs
Alternative 1, if implemented, will not comply with the
chemical-specific ARARs because ground water that contained
contaminants with concentrations in excess of the clean-up
goals will remain unmonitored. Location- and action-specific
29
-------
ARARs will not be applicable because no action will occur.
The remaining alternatives will comply with all state and
federal location- and action-specific ARARs assuming that
natural attenuation and in-situ vapor extraction will be
effective.
10.3 Long-Term Effectiveness and Permanence
Because no remedial actions will occur, a long-term risk will
be associated with Alternative 1 *as long as clean-up goals
are exceeded. The possibility exists for greater volumes of
ground water to become contaminated under Alternative 1.
This is also true for Alternatives 2 and 4. However, an
active monitoring program will be implemented in Alternatives
2 and 4 to determine if natural attenuation is occurring and
to determine the migration pathway of the plume. For
Alternative 1, no mechanism exists to determine if
concentrations increase or decrease, other than during the
five-year reviews. Thus, the long-term risks will be greater
with Alternative 1 than with Alternatives 2 and 4.
Alternatives 3 and 5 will have less of a long-term risk than
the other three alternatives. A long-term risk will not be
associated with the treated ground water in Alternatives 3
and 5. However, a long-term risk will remain with the
untreated aquifer until clean-up levels are met. Alternative
5 will offer permanence earlier than the other four
alternatives because in addition to active containment of the
ground water, the residences will be connected to the public
water supply system and no ongoing maintenance will be
required. Alternatives 3 and 5 will be expected to reach
containment in a few months.
30
-------
The amount of time to reach clean-up goals under Alternatives
2 and 4 is 20 years, based upon preliminary modeling
information. Five-year reviews would be required for all
alternatives to assure that the remedy remains protective.
These reviews will be included as part of the remedial
action(s) for the entire 57tn & N. Broadway site which will
take over the actions in the Riverview OU.
The proposed monitoring plans and/or treatment technologies
in Alternatives 2, 3, 4, and 5 sbt
-------
and replacement. Alternatives 3 and 5 will achieve the
remedial action objectives in the shortest amount of tine.
10.4 Reduction of Tcxicity, Mobility, and Volume through
Treatment
It is unknown at what rate a reduction in toxicity, mobility,
or volume will occur in Alternatives 1, 2, or 4.
Alternative 1 provides no mechanisms to determine if
reduction is occurring. Monitorijag will be performed in
Alternatives 2 and 4; however, it may take several rounds of
sampling to determine if natural attenuation is occurring. A
reduction in toxicity, mobility or volume will occur on a
more expedited basis under Alternatives 3 and 5. The ground
water treatment will be irreversible. No residual waste
material will be produced from any of the alternatives.
Alternatives 3 and 5 will meet the statutory preference for
treatment because some treatment is occurring.
10.5 Short-Term Effectiveness
The risk to the community and workers will be minimal for all
alternatives. None of the risks will be uncontrollable.
Residents may be exposed to noise and dusts during
construction of the connections to the public water supply
under Alternatives 4 and 5. These risks will be controlled
by the use of dust suppressants as necessary. The risk to
workers will be controlled'by proper use of personal
protection equipment and monitoring during site activities.
However, workers are not expected to come into contact with
contaminated ground water.
The time to achieve clean-up levels will be greatest for
Alternatives 2 and 4. It is estimated that the time to
32
-------
achieve clean-up goals for chese alternatives will be
20 years, based en preliminary modeling because no treatment
will take place. The time to achieve remedial action
objectives for Alternatives 3 and 5 is estimated to be less
because active treatment will occur. Under Alternative 1
there will be no method to check on the contamination.
10.6 Implementability
«
Because no actions will be taken taring Alternative 1, this
criteria is not applicable. Alternative 2 will be the
easiest of the alternatives to implement. Alternative 2
requires the installation of household GAC treatment units
and ground water monitoring.. Alternatives 3 also includes
the installation of household GAC treatment units and ground
water monitoring, but will require additional efforts
including the installation of in-situ vapor extraction wells
and treatment system components. Alternative 4 and 5
involves the connections to the public water supply system
and/or the installation of in-situ vapor extraction wells and
treatment system components. Alternative 4 will be easier to
implement than Alternatives 3 and 5 because with
Alternatives 3 and 5, in addition to the installation of GAC
or connection to the public water supply system, ground water
treatment/containment systems will be installed. The
technology used in Alternatives 3 and 5 is an innovative
technology.
The necessary equipment and personnel required to implement
each alternative are readily available. Pilot scale and
bench scale tests may be required for Alternatives 3 and 5.
More than one vendor is available for each alternative to
provide a competitive bid.
33
-------
10.7 COSC
The cost comparisons for the alternatives include che
detailed cost estimates for each alternative and the
sensitivity analysis that evaluates the impact of changes on
the total present worth of each alternative. Table 10-2
lists the costs for each of the five alternatives.
10.7.1 Individual Cost Comparison
«..*=
Only 0&M costs converted to a total present worth will be
associated with Alternative I. The total present worth of
Alternative 1 will be the lowest at no cost. The total
present worth cost of Alternative 3a, leasing filters, will
be the.greatest at a cost ranging from $481,110 to $625,590,
although the high range for Alternative 5 is greater. The
total present worth costs of Alternative 2a, leasing filters,
ranges from $308,250 to $392,250. Alternative 3b, purchasing
filters, has a cost range of $430,710 to $562,590.
Alternative 5 has costs ranging from $451,710 to $661,690.
The total present worth cost for Alternative 2b may be the
lowest of the active alternatives with a range from $245,250
to $313,500. The total present worth cost for Alternative 4
has the potential to be the lowest of the active alternatives
and will range from $219,000 to $366,750.
10.7.2 Cost Sensitivity of the Alternatives
Cost estimates involve making assumptions and engineering
judgment. However, EPA has attempted to be consistent in the
assumptions used to assure that the cost comparisons are
fairly made. The cost sensitivity of each alternative is
related to varying expected costs of key components of the
alternatives. It is anticipated that Alternatives 3 and 5
34
-------
have the greatest cost sensitivity because they have the most
cost items associated with them. If additional in-situ vapor
extraction wells are required, the cost of the alternatives
will increase based on the costs for installing the
additional wells and operating the vapor extraction system at
the additional wells. The costs of Alternatives 2 and 4 are
sensitive to the number of residences affected by the
contaminated ground water plume. If the areal extent of the
ground water plume increases, then the number o£ households
requiring GAG units or connectiorja^to the public water supply
system increases accordingly. For purposes of estimating, it
will be assumed that the number of households will be
increased by 25% for Alternatives 2 and 4. This increase is
to account for the wells which will become contaminated by
the uncontrolled contaminant plume as it moves. In addition,
if natural attenuation of the ground water contamination
plume does not occur, then additional remedial action may be
required, also increasing the costs of these alternatives.
10.8 State Acceptance
In a letter dated April 28, 1998, the State Project Manager
for the 57th & N. Broadway site provided additional
information concerning the analytical results from the
monitoring of the plume in the Riverview OU. In this letter,
the state stated its agreement with the implementation of
Alternative 5 and provided specific recommendations as to the
coverage of the 'affected area'. The EPA's determination of
the 'affected area' contains the entire area recommended by
the state. The state has favored Alterative 5, in principal,
throughout the process of evaluating the options for remedial
action at the Riverview OU.
35
-------
Community Acceptance
There has been strong community support and demand that
residents be connected to the public water supply since early
in the process of investigating the Riverview CU. The only
points of concern have been the amount of participation the
property owners would be required to make in the payment for
receiving public water. The selected remedy does not provide
for the payment of the property assessment that all property
owners in the area will be required to pay whether or not
they elect to connect to the city's water system, and there
is strong public opinion that the assessment should be
included in the cost born by EPA. One comment also implied
that the monthly water bills should also be included in the
cost paid by EPA.
Two additional areas of concern are with the determination of
the area of 'affected residents' and the potential for the
treatment/containment system to become a noise and physical
nuisance. The EPA has taken note of the residents' concern
with noise which may result from the operation of the
treatment/containment system and will make every effort to
design the system so that it has as little impact on the
community aesthetics as possible.
Community acceptance is specifically addressed in the
Responsiveness Summary, Appendix 1. The Responsiveness
Summary provides a thorough review of the significant public
comments received on the Proposed Plan, and EPA's responses
to the comments. The community has expressed support for the
remedy selected as described in the Proposed Plan.
36
-------
11.0 SELECTED REMEDY
Based upon consideration of the requirements of CERCLA and
the NCP, the evaluation of the relative performance of each
alternative with respect to the nine criteria, and
consideration of comments received during the public comment
period, EPA has determined that Alternative 5 is the selected
remedy. The selected remedy contains the following elements:
Up to 54 residential properties which are currently using
water above MCLs or are threatened with contamination
above MCLs will be connected to the City of Wichita's
public water supply;
*
The contaminant ground water plume will be
treated/contained by an in-situ ground water vapor
extraction system to be designed for the specific
locality; and
A ground water monitoring system will be designed and
additional well(s) installed to monitor the Riverview OU
contaminant ground water plume, until the remedial action
for the entire 57--"1 & N. Broadway site is implemented and
takes over or replaces the action in the Riverview OU.
This is expected to happen within the next three years or
less.
11.1 Connection of Residential Properties to Public Water
Supply
After evaluation of the plume, the contaminant concentrations
in the ground water, and the potential for future migration,
it has been determined that up to 54 residential properties
37
-------
which rely on private wells containing contamination above
the MCLs or which are threatened with contamination exceeding
the MCLs will be eligible for connection to the City of
Wichita's public water supply. See Figure 4.
In order to be eligible for connection, a property must first
be one of the 54 residential properties illustrated in Figure
4 and listed in Table 11-1. In addition to being a
designated property, it must also meet the following
conditions. First, the residenc^^must have been a permanent
residence in existence in its present location prior to
February 11, 1998. The residence must currently rely upon
ground water from a working private well physically connected
to the residences household distribution system as its source
of domestic water. The use of bottled water for drinking
will not affect eligibility.
The EPA shall arrange for the following work at no cost to
the property owner of eligible properties: tap the water main
in the street and bring it to an approved meter; set the
meter; permanently sever the connection from the residents
private well and the household distribution system; evaluate
the household distribution system to determine if a pressure
reduction valve is necessary to safely connect to the city's
system; if determined necessary, install a pressure reduction
valve; connect the household distribution system to the
public water supply; and restore landscape disturbed by the
above-described activity.
Costs that will not be covered include the property
assessment leveed against the property for the improvements.
These costs are leveed without regard to the property owner's
election to connect to the public water supply. The selected
remedy will not cover the monthly water bills incurred by the
38
-------
N
2 ppb vinyl chloride plume boundry
Affected Properties
Property currently on Park City Water
RIVERVIEW OU
Affected
38-a
FIGURE 4
-------
AFFECTED PROPERTIES
TABLE 11-1
4841 Arkansas Avenue
4901 Arkansas Avenue
4909 Arkansas Avenue
4917 Arkansas Avenue
4700 Armstrong Drive
4701 Armstrong Drive
4715 Armstrong Drive
4723 Armstrong Drive
4732 Armstrong Drive
4752 Armstrong Drive
4801
4802
4812
4815
4823
4824
4826
4845
4906
4918
4801
4835
4840
4848
4857
4858
4900
4901
Jeanette
Jeanette
Jeanette
Jeanette
Jeanette
Jeanette
Jeanette
Jeanette
Jeanette
Jeanette
Kimberly
Kimberly
Kimberly
Kimberly
Kimberly
Kimberly
Kimberly
Kimberly
Avenue
Avenue
Avenue
Avenue
Avenue
Avenue
Avenue
Avenue
Avenue
Avenue
Lane
Lane
Lane
Lane
Lane
Lane
Lane
Lane
-4919
-.4-920
4931
4932
4944
4945
4955
4956
Kimberly
Kimberly
Kimberly
Kimberly
Kimberly
Kimberly
Kimberly
Kimberly
Lane
Lane
Lane
Lane
Lane
Lane
Lane
Lane
5003 North Shelton
5014 North Shelton
5015 North Shelton
5024 North Shelton
5060 North Shelton
800 West 46ch Street North
812 West 46th Street North
820 West 46th Street North
826 West 46th Street North
755 West
801 West
811 West
819 West
825 West
835 West
47th Street
47th Street
47th Street
47cb Street
47th Street
47th Street
North
North
North
North
North
North
728 West 49th Street North
731 West 49th Street North
740 West 49th Street North
38-b
-------
residents once connected to the system. Once installation is
complete, ail future maintenance issues will be considered by
EPA to be between the property owner and the City of Wichita.
11.2 In-Situ Vapor Extraction
In order to contain the plume in its present location, an
innovative technology some times referred to as 'in-well
stripping' will be employed. A single well will be installed
in the plume to evaluate the tectj&ology' s effectiveness in
the Riverview OU's location. Based upon information obtained
in that evaluation, a system of wells will be designed to
contain the plume in its present location. It is expected
that due to the nature of the technology, some treatment of
the plume will occur and that some shrinkage of the plume may
occur. The main goal is to minimize further migration of
the plume found in the Riverview OU. It has been assumed,
for estimating purposes, that five wells will be required to
contain the plume. The actual number will be determined when
the information from the test well is available.
The number and location of equipment buildings required to
operate the system will be evaluated as well, keeping in mind
the local concern that there may be a problem with noise and
visual aesthetics. Every effort will be made to ensure that
the system has as little impact on the quality of life in the
Riverview neighborhood as reasonably possible.
11.3 Groundwater Monitoring
The EPA has an existing monitoring well near the northeastern
end of the Riverview OU contaminant ground water plume. The
State of Kansas has installed five additional monitoring
wells within and around the plume. At present, no well has
been established downgradient of the plume. .A final
monitoring well system will be designed using the existing
39
-------
monitoring wells. Upon further evaluation of the existing
monitoring wells it will be determined if more monitoring
wells, in addition to the proposed down gradient monitoring
well, are needed to adequately monitor the Riverview OU
plume.
If it is determined that the plume is likely to migrate
beyond the currently designated 'affected area', a decision
will be made at that time to take action to prevent the
*
migration or to assist threateneij.'jfer.esidences with connection
to the public water system. Residential wells exceeding MCLs
for contaminants from the Riverview OU plume will be deemed
"affected residents".
11.4 Cost Estimated to be Associated with the Selected
Remedy
Table 11-2 contains the cost estimate associated with the
implementation of the selected remedy.
11.5 Estimated Outcome of Selected Remedy
The estimated outcome of the selected remedy is that all
residents whose primary drinking water supply is contaminated
or is threatened to be contaminated at levels greater than
the MCLs will be supplied with an alternate water supply from
the City of Wichita's public water system. In addition, it
is expected that the plume' will be contained and the chance
of further migration reduced. It is anticipated that all
eligible residences will be connected to the public water
supply within sixty to ninety days of the signing of the ROD,
and that the monitoring system will be completed within 90 to
120 days of the signing of the ROD. A routine monitoring
program will be established. Monitoring will be taking place
with the existing wells prior to that if necessary. It is
40
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Table 11-2
Cost Estimate
Alternative 5 - Provide Public Water and Plume Containment
CCJGI Estimate Quantity
Units
Range of Unit Cost
Range of Capital Cost
Range of Annual Coot
Capital Cost
Conni'cl to Wichita Water 60
Install 5 in-well strippers 250
OA/P.impl ing 60
Direct Capital Cost Subtotal >
Administrati 311 Costs 10\
Engineering Design
Total Capital Cost
EA
VLF
1IR
\
S2000
$350
S60
$3500
$450
$90
$120, 000
$87, 500
$3,600
$211, 100
$21. 110
$3500
$235, "710
$210, 000
$112,500
$5,400
$327, 900
$32,790
$7000
$367, 690
Annual O & M Costs
Monitoring - Years 1-3
containment 5 wells per quarter
lolal samples 20
EA
$900
$1, 300
$18 , 000
$26, 000
Vapor Extraction System
Monthly O & M cost per month 12
Total Present Worth of OiM
Total Present Worth
MO
$4 , 500
$6, 000
$451,710
F$661,690
$54 , 000
$216. 000
$72, 000
$29-1 . 00
0
41
-------
anticipated that the 'in well' stripper system will be
installed and functioning in this construction season.
12.0 STATUTORY DETERMINATIONS
Under its regal authority, EPA's primary responsibility at
Superfund sites is to undertake remedial actions that achieve
protection of human health and the environment. In addition,
Section 121 of CERCLA establishesL'^several other statutory
requirements and preferences. These specify that when
complete, the selected remedial action for this site must
comply with ARARs unless a statutory waiver is justified.
The selected remedial action must also be cost-effective and
utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum
extent practicable. Finally, the statute includes a
preference for remedies that employ treatments that
permanently and significantly reduce the volume, toxicity, or
mobility of the hazardous waste as their principal element.
The following subsections discuss how the selected remedy for
the Riverview OU meets these statutory requirements.
12.1 Protection of Human Health and the Environment
The selected remedy protects human health by providing an
alternate source of domestic water for residences whose water
supply is currently or is threatened to be contaminated with
volatile organic contaminants. Additionally, it will contain
or treat the contaminant plume preventing movement to areas
currently not contaminated.
Implementation of the selected remedy will not pose any
unacceptable short-term risks or cross-media impacts to the
site, the workers, or the community.
42
-------
Compliance with Applicable cr Relevant and Appropriate
Reauirements
The selected alternative for the Riverview OU will comply
with all ARARs for the site. The following are the federal
and state chemical-specific ARARs and TBCs that pertain to
the selected remedy.
Safe Drinking Water Act.
-- National Primary Drinkiag-Water Standards; 40 CFR
Part 141, Subparts B & G.
-- National Secondary Drinking Water Standards; 40 CFR
Part 143.
-- Maximum Contaminant Level Goals; 40 CFR Part 141,
Subpart F.
Clean Water Act.
-- Ambient Water Quality Criteria; 40 CFR Part 131.
Clean Air Act.
-- National Primary and Secondary Ambient Air Quality
Standards; 40 CFR Part 50.
-- National Emissions Standards for Hazardous Air
Pollutants; 40 CFR Part 61.
Kansas Ambient Air Quality Standards and Air Pollution
Control Regulations; KAR 28.19.
Kansas Water Quality Standards; KAR 28.16.28.
Kansas Drinking Water Rules; KAR 28.15.
Remedial standards for ground water remediation have been
adopted from the National Primary Drinking Water Standards
and the Kansas Water Quality Standards. Discharge of the off
gases to the atmosphere will be regulated by standards set
forth in the Clean Air Act and the Kansas Ambient Air Quality
Standards and Air Pollution Control Regulations.
43
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The following are rhe federal and state action-specific ARARs
that certain re the selected remedy.
Occupational Safety and Health Act.
Clean Water Act.
-- Ambient Water Quality Criteria; 40 CFR Part 131.
Clean Air Act. ^-
-- National Ambient Air Quality Standards; 40 CFR
Part 50
-- Noise Control Act of 1972; 42 USC Section 4901 e_t
seq.
^
Environmental Protection Act.
-- Kansas Ambient Air Quality Standards and Air
Pollution Control Regulations, KAR 28.19.
Off-gas discharge will be managed in accordance with the
Clean Air Act and the Kansas Ambient Air Quality Standards
and Air Pollution Control Regulations. The treatment wells
will be registered with the State of Kansas. All activities
at. the site will comply with OSHA. This alternative will
comply with ARARs by containing the plume and providing
uncontaminated water for domestic use.
12.3 Cost Effectiveness
The selected remedy is cost-effective because it has been
determined to provide overall effectiveness proportional to
its cost, estimated at a present worth of between $451,710
arid $661,690. The overall permanence and reduction of risk
to human health is significantly greater for the cost than
for the other remedies.
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12.4 Utilization cf Permanent Solutions and Alternative
Treatment Technologies to the Maximum Extent
Practicable
The EPA believes that the selected remedy represents the
maximum extent to which permanent solutions and treatment
technologies can be utilized in a;.s£ost-effective manner for
the Riverview OU. Of those alternatives that are protective
of human health and the environment, and that comply with
ARARs, EPA has determined that this selected remedy provides
the best balance of tradeoffs in terms of long-term
effectiveness and permanence; reduction in toxicity,
mobility, or volume achieved through treatment; short-term
effectiveness; implementability; and cost. The selected
remedy considers the statutory preference for treatment as a
principal element, as well as state and community input. The
selected remedy treats and destroys a greater amount of the
site contaminants than the other alternatives. The selected
remedy reduces the toxicity, mobility, and volume of
contaminated material at the site through treatment as
described above.
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APPENDIX A
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RESPONSIVENESS SUMMARY
RIVERVIEW OPERABLE UNIT
OF THE
57 & N. BROADWAY SITE
SEDGWICK COUNTY, KANSAS
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INTRODUCTION
The purpose cf this document is to address the questions
raised concerning the proposed plan for the Riverview Operable
Unit (OU) of the 57-" Sc N. Broadway site. The proposed plan was
made public for comment on April 2, 1998. A thirty-day comment
period ended on May 1, 1998. This document will address and
consider all comments made during that period which could have an
impact upon the Proposed Plan. The two main forums which the
United States Environmental Protection Agency (EPA) receives
comments on proposed plans are during the Public Hearing for the
proposed plan, which was held on April 16, 1998, and through
written comment generated during the public comment period.
COMMENTS RECEIVED DURING THE PUBLIC HEARING APRIL 16, 1998
A court reporter recorded the Public Hearing and a
transcript of that hearing is available in the administrative
record.- This summary will not attempt to reproduce all that took
place during that meeting, but will specifically address those
questions posed which have relevance to the proposed plan.
The comments which were presented during the public hearing
did not oppose the basic elements of the proposed plan. Some
questioned the feasibility of some of the components of the plan,
while others were more inquiries concerning specifics of
definitions used in the plan.
A good number of the comments/questions dealt with concerns
over what EPA would eventually define as being the "affected
area". These concerns were broken down into three general areas:
ground water plume size; plume movement; and levels of exposure
that would be determined as triggering eligibility under EPA's
criteria for assistance with connecting to the City of Wichita's
public water supply.
In answer to the questions regarding service area, EPA has
identified in the Record of Decision (ROD) the specific
properties which are eligible for assistance in connecting to the
City of Wichita's public water system. An explanation is
provided below regarding the available information on plume size
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and movement. A subsequent discussion on the issue of
eligibility criteria is provided in a question and answer format
beginning on page 3 of this responsiveness summary.
Plume Size: There was concern that EPA had yet to identify
the location of the contamination plume. The EPA has based its
estimate of plume size upon contamination found in the ground
water at concentrations above the drinking water standards.
There are three specific contaminants which have been found in
the Riverview Operable Unit (OU) that exceed these standards for
public water supplies. These standards, referred to as Maximum
Containment Levels (MCLs), are many times used as levels to judge
water quality for private water supplies, like the wells used in
the Riverview area. The MCL for vinyl chloride is two parts per
billion (ppb). Since the vinyl chloride two ppb plume covers the
same or a larger area than either of the other two contaminants,
it was determined that it would be used to identify the outline
of the contaminant plume.
The plume has been identified by using information gathered
during a series of ground water sampling events conducted by EPA,
the Kansas Department of Health and Environment, and the Wichita-
Sedgwick County Department of Community Health. These sampling
events were conducted between December of 1997 and April of 1998.
Based on currently available information from these four separate
monitoring events, it appears that there will be little or no
lateral movement of the plume. The EPA will continue to monitor
the plume using a monitoring system designed to provide data on
the plume size in the unlikely event there is a change in plume
size in any direction.
Plume movement: Several questioners were concerned that
either under existing conditions or future changed conditions the
plume would move laterally and expose those who are currently not
being exposed. Given the information provided by the four
sampling events mentioned and given our understanding of the site
setting, EPA does not believe the plume will expand laterally.
It could, however, eventually migrate to the southwest. The
monitoring plan previously mentioned will detect any such
migration.
Several questions were raised concerning the potential of
the plume shifting as the result of future changed conditions,
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i.e., given the properties of the aquifer, the pumping of the Bel
Aire well field, and the total cessation of the use of ground
water for domestic use, and our currently available information-
EPA could expect minimal expansion of the plume. The EPA has
considered this potential for expansion as a basis to include
residents outside the current plume as threatened residences and,
thus included, these residents in the area of "affected
residents". In an aquifer with more limited resources, such an
occurrence could result in a plume shift; but given the vast
quantities of water available and the quick recovery time of the
aquifer, such an effect may not be measurable.
QUESTION: At what contaminant level would EPA determine a
residence to be eligible for assistance?
ANSWER: All residences within the plume area identified by the
two ppb vinyl chloride plume and some in adjacent 'buffer' areas
will be eligible. Residents eligible for assistance will be
identified by address in the ROD.
Comments concerning the level of contamination that should
trigger eligibility have been varied. One comment stated that if
any level of contamination was found in the well water, that
should trigger eligibility. Others stated that everyone close to
the area should be included. Another stated that those who were
provided bottled water and/or filters should be eligible. The
EPA must conduct business within the limits of the Superfund law
from which our authority is derived. The EPA can provide
alternate drinking water to those who are currently exposed or
threatened by the contaminated water. This brings us back to
establishing the eligibility criteria to those who are currently
exposed to water that exceeds drinking water standards and those
who may become exposed to such conditions. In establishing the
final criteria in the ROD, .the comments concerning the potential
for future migration of the plume has been fully considered in
determining who will be included in the "threatened" category.
QUESTION: Will there be a general health study of the area?
Answer: The ROD will not contain a requirement for a health
study.
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Although the proposed plan does not and the remedy for the
Riverview OU will not contain anything concerning health studies
or health education, this is an area of significant concern to
the residents of the area. The representatives of the Agency for
Toxic Substance and Disease Registry (ATSDR) attempted to respond
to the numerous questions on health effects. Mr. Parker of ATSDR
stated there is no way to test or identify the effects of low
levels of contamination over relatively short exposure periods.
ATSDR did commit to make agency resources available to provide
information to individuals and physicians and were exploring the
possibility of advancing another physicians education session for
the area. ATSDR held a public availability session on May 14,
1998, to provide additional health information.
QUESTION: How many * in well' strippers will be used and where
will they be placed?
ANSWER: The exact number and placement of the 'in well' strippers
will not be determined until a pilot well is installed and
tested. This will take place during the remedial design phase
for the 'in well' strippers.
QUESTION: How much noise will the 'in well' Strippers make?
ANSWER: The machinery for the system will be housed in a small
building which will be insulated to reduce the noise to a
minimum.
QUESTION: Will the strippers be secure from children and
vandalism?
ANSWER: The building(s) containing the mechanical equipment will
be locked securely and the wells themselves will also be secured
and locked in such a way to. discourage tampering. These
buildings and associated equipment will be routinely inspected.
QUESTION: Will the 'in well' strippers work?
ANSWER: Similar systems have been used in a wide variety of
settings to treat contaminants of a similar nature. It is
expected that the system will perform very well in the Riverview
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area. How well the lin well' stripper works cannon be determined
until it is actually functioning.
QUESTION: Will the vin well' strippers address all of the
contaminants?
ANSWER: The ' in well' strippers will address all volatile
organic chemicals including those which are a problem in the
Riverview area.
QUESTION: Will the 'in well' strippers cause contamination to be
drawn to the area?
ANSWER: Since no water will be removed from the well, this will
not be a concern.
QUESTION: Where will the VOCs removed from the ground water end
up? Will the VOCs removed from the water become an inhalation
risk?
ANSWER: The VOCS will not be an inhalation risk. If the design
of the strippers allows the VOCs to be released to the air, the
levels will be significantly below the air quality standards of
the EPA or the State of Kansas.
QUESTION: Has EPA considered the use of phytoremediation?
ANSWER: Phytoremediation calls for the dense planting of
vegetation, often poplar trees, which is noc desirable in a
residential neighborhood. It may be considered in the overall
57th & N. Broadway site plan.
QUESTION: One questioner asked why source control had not been
considered?
ANSWER: It was explained that the purpose of the Riverview OU is
to provide a source of alternative drinking water, control the
plume to prevent the spread of contamination, and to monitor the
plume to assure the actions were working as planned. Source
control will be considered as a portion of the remedy for the
entire 57-~ & N. Broadway site.
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QUESTION: Cne individual inquired to the possibility of EPA
reimbursing individuals for connecting to a public water supply.
ANSWER: The ZPA is prohibited from reimbursing individuals.
QUESTION: Cne individual asked if the filters that EPA has
installed in the residences would remove vinyl chloride because
an information source she had found stated that the only way to
remove vinyl chloride was through aeration.
ANSWER: It was explained that vinyl chloride and other VOCs had
been successfully removed from water using carbon filtration.
This completes the summary of the comments received during
the Public Hearing of April 16, 1998.
COMMENTS RECEIVED FROM THE STATE OF KANSAS
The State of Kansas did not provide specific comments to the
proposed plan, but did make specific recommendations as to the
affected area. The state's recommendation is based on the four
rounds of sampling that has been taken at the site. After
reviewing the state's recommendation and the data from the five
rounds of sampling along with the comments from the contractor's
geohydrologist concerning how ground water usage in the future
will affect the plume, EPA agrees with the state and will reflect
that recommendation in the ROD.
COMMENTS RECEIVED FROM THE WICHITA-SEDGWICK COUNTY HEALTH
DEPARTMENT
The following comments and questions were made in addition
to those made at the public hearing.
COMMENT: "EPA should fund connections to the city's water supply
for all properties with domestic wells that currently have
detectable levels of volatile organic compounds as identified in
the Riverview Operable Unit Groundwater Contamination Plume.
This includes consideration of all groundwater analysis data
conducted by the City-County Health Department, Kansas Department
of Health and Environment, EPA contractors and EPA staff. This
includes all domestic wells in and around the plume that are
either above, at or below MCLS." In addition, "EPA should
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consider funding connections chat would include all properties
which are adjacent ~o, threatened by, or are down gradient of the
Riverview volatile organic compound plume."
RESPONSE: The EPA can provide alternate drinking water to those
who are currently exposed or threatened by the contaminated
water. In establishing the final criteria in the ROD, the
comments concerning the potential for future migration of the
plume have been fully considered in determining who will be
included in the "threatened" category.
COMMENT: "Water well samples from domestic wells may not give an
accurate assessment cf the level of contaminates in ground water,
therefore some of the data generated regarding well contamination
may have indicated lower levels of contamination than actually
exist in the domestic drinking water supplies." "Domestic water
wells are usually drilled to differing depths and seldom have
information available regarding the well construction.
Therefore, one domestic well may show the presence of volatile
organic compounds while an adjacent well may not or may have
different concentrations due to the differing depths where the
well screens are set. Just using data gained from domestic water
well sampling may not adequately predict the location and size of
the groundwater contamination plume."
RESPONSE: The potential always exists that tap samples may not
be representative of the ground water beneath the house being
tested; however, great care was taken in obtaining these samples,
and they at the very least represent the water being consumed by
those using the wells. In addition, geoprobe samples taken by
the City-County Health Department and monitoring well samples
taken by KDHE provide additional verification of the plume
location. Five separate sampling events performed by four
different entities all returned essentially the same results
regarding the plume location.
COMMENT: Other factors to consider are the " Changes due to
seasonal variation of the groundwater flow and direction (changes
in groundwater elevation)."
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RESPONSE: Changes of ground water -elevation or seasonal
variations in flow are not anticipated to create a chance in the
plume.
COMMENT: Other factors to consider are changes in local ground
water flow direction due to usage of the Bel Aire well field.
RESPONSE: Modeling of the plume has indicated that the Bel Aire
well field has a minor effect on the present plume, but its
influence is limited and does not appear to be a major factor in
the future migration of the contaminant plume under any
circumstances foreseeable.
COMMENT: "Additional groundwater contamination may migrate into
the northeast part of the Riverview area and impact additional
domestic water wells."
RESPONSE: Based on currently available information regarding the
site setting, EPA believes that contamination from the plume to
the northeast of the Riverview area would migrate along the same
path as the current contamination has taken. Future remediation
of the northeast portion of the plume should also provide
additional protection.
COMMENT: "The southwest end of the groundwater plume is not well
defined."
RESPONSE: The southwest end of the ground water plume has not
been determined. It is apparent that no one is threatened by any
southwestern extension of the plume at the present time or in the
near future. The monitoring well system established during the
remedial action will define, the southwest end of the plume.
QUESTION: Will additional residences be impacted in the future as
the remediation process is implemented?
ANSWER: It is anticipated that the remediation process, i.e.,
'in-well' stripers, will maintain the plume in its present
location or reduce its area of coverage.
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QUESTION: Will the deeper part of the plume migrate into areas or.
the other side of the Little Arkansas River?
ANSWER: See previous answer.
COMMENT: "As an intermediate measure for the protection of public
health, ail residences in the plume areas should be considered to
receive bottled water and whole house filters until public water
connection is made."
RESPONSE: The EPA is currently providing bottled water and whole -
house filters to all the residents who are currently at risk and
have requested such assistance.
COMMENTS RECEIVED FROM THE PUBLIC
The EPA received several comments from the public, either
via the United States Postal Service or e-mail. A listing of
those whose comments were received is given below. The EPA is
providing answers for those questions which have not already been
answered above.
Comments were received from:
Sylvia Forte via e-mail
Kris Hill via e-mail
Mary Jean Kendall via U.S. mail
Terri L. and David L. Nigg via U.S. mail
Darren and Jamie Olmsted via U.S. mail
D. Robbins via e-mail
Janice & Howard Tice via e-mail
Fred & Patricia Urban via U.S. mail
William K. White via U.S. mail
QUESTION: How long will it take to control the plume?
ANSWER: Until we can field test the 'in well' strippers, it is
not possible to speculate how long it will take, the number, or
the placement of the 'in well' strippers. We will begin the
design of the system by placing one 'in well' stripper at a
location yet to be determined and evaluate its performance to
complete the design of the remainder of the system. At that
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time, we will be better able to estimate the length of time it
will take to control the plume. However, we currently believe
that once the 'in well' strippers are in place, the affected
portion of the plume will become stable in a short period of
time.
QUESTION: How long will it cake to remove the contamination?
ANSWER: The ' ir. well' strippers will remove some of the
contamination, but it is not their purpose to completely clean up
the plume. Cur goal with this particular action is to control
the plume and prevent it from moving from its current location.
The decision concerning the clean up of the entire plume will be
made when the ROD for the entire 57th & N. Broadway site is
written.
COMMENT: The EPA should get the responsible parties to pay for
both the provision of water and to stop the spread of
contamination.
RESPONSE: The EPA agrees homeowners affected and threatened by
the contamination should have the installation of the alternate
water supply provided, and the responsible parties should be
required to pay the cost.
QUESTION: We would like to have all of the names of the
suspected companies which contributed to the pollution of our
well water system.
ANSWER: The EPA has yet to determine all of the companies which
may have contributed to the ground water problems at the 57th &
N. Broadway site. The same potentially responsible parties will
be involved in our investigations of the Riverview OU. The
companies we have notified as potentially responsible are:
Midland Refinery Inc.; Wilkco Paint Inc.; Farmland Industries
Inc.; Clearwater Truck Company Inc.; Koch Industries; and Lewis
Williams Junior.
QUESTION: The first and second water tests have lots of
different information. Who conducted these tests? We are aware
that EPA collected the samples, but what company did the actual
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laboratory work? What are all of the other chemicals listed on
the second report?
ANSWER: The first set cf samples was collected by EPA's
contractor, Black and Veatch (3&V). B&V hired Pace Analytical for
the laboratory analysis. In that analysis, only five specific
compounds found in previous samples were analyzed. The second
set of samples were taken by EPA personnel and analyzed in the
EPA laboratory. The second report listed all of the chemicals
that can be found in an analysis of the type used to look for the
specific chemicals suspected to be present in the Riverview
neighborhood. The main difference between the two reports is
chat the second one reported a large number of chemicals that the
method used for the analysis could find, while the first report
only identified those chemicals that were expected to be found
based upon previous analytical work. Accordingly, the second
report listed a lot of chemicals that were not found along with
those that were found.
COMMENT: A commenter asked EPA to pay for all costs associated
with providing water to the neighborhood, including monthly water
usage bills.
RESPONSE: The EPA only considers it appropriate to provide the
cost associated with actual connection to the city water system.
Through this connection, a safe water supply can be delivered.
The assessment is leveed against everyone in the benefit district
whether the property owner elects to connect to the public water
system or not. The resident controls the water usage for each
residence. Neither of these costs is appropriate for EPA
expenditures.
QUESTION: The Quik Trip at 53rd & Broadway is at this moment
cleaning and/or drilling to clean up something. What anticipated
effect is this effort going to have on the problems we already
have? Are you going to get involved in testing to see if these
cleaning techniques will have an effect upon the plume?
ANSWER: The proposed plan has provisions for continued monitoring
of the plume. If activity associated with the Quick Trip clean
up has an effect on the plume, it will be detected by the
monitoring system. The clean up proposed for that problem is
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not expected to extend very far from the site. If it should
reach farther than expected, it could conceivably be beneficial
to cleaning up the Riverview plume. It is not expected that any
negative impact would be experienced.
QUESTION: We have a swimming pool. The medical person whom you
brought to the meetings assured us that it will be safe to
continue to use the well water for the pool (since the vinyl
chloride fumes will dissipate in the outside air). We will
continue to use the well water for our pool. How can we be
assured that the water will be tested in the future. It is our
fear that the water will be much more polluted once ours is one
of the few wells pumping from this site.
Answer: The ground water monitoring results will be available to
let you know on an ongoing basis the condition of the ground
water. It would not be expected that the number of wells pumping
would influence the quality of the ground water in a particular
well. "The contamination in your well is there whether your well
pumps it out or not, and it is not significantly affected by the
amount of water being pumped by other households in your
vicinity.
QUESTION: The "Doghouse(s),"associated with the 'in well'
strippers, that will be placed on land in the area for the clean
up are of great concern to all of us. We would like to have
exact locations of current systems in Kansas so that we may visit
those area(s) to determine for ourselves the extent of sound and
the appearance and placement of the structures.
ANSWER: Two systems have been active in the State of Kansas, but
neither are currently operating. Each project is unique and the
placement and number of wells and equipment buildings will vary
depending upon the site specific conditions.
QUESTION: For those persons who have these "doghouses" placed on
or immediately adjacent to their homes, will the EPA be providing
financial remuneration for the loss of property values? Needless
to say, the entire area has suffered this same loss, but those
persons who have to deal with these doghouses may never ever
recover from the financial losses.
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ANSWER: It cannot be determined what, if any, effect the presence
of an active treatment system may have on the property value of a
specific piece of property. The fact that the contamination is
being dealt with and the presence of a public water supply system
should have a positive impact on the property values in the
entire area. The EPA has no provisions to reimburse property
owners for the placement of treatment systems on their property
which may or may not impact property values.
COMMENT: One commenter stated that long-term health testing and
monitoring should be a part of this package, especially for the
young people and senior citizens.
RESPONSE: Additional health information has been and will
continue to be disseminated in the entire 57-n & N. Broadway site
area.
COMMENT: The commentor is concerned with the effect of the
contaminated ground water upon property value and states that,
"We should be compensated for loss of property values...".
RESPONSE: The Superfund program is not able to compensate
property owners for 'loss of property value'; and therefore,
there is no provisions for that in the selected remedy for the
Riverview OU.
COMMENT: The data provided on the private wells tested appear to
present only a pass fail analysis. It did not provide the
recorded values of the contaminants. The commenter feels that
the recorded values should have been listed instead of simply
stating that the MCLs had not been reached.
RESPONSE: All letters from-.the City-County Health Department,
KDHE, or EPA contained an analytical data sheet showing the
detection limits and the levels at which contaminants were found
or that no contaminant was found above the stated detection
limit; or stated the level of contaminants found and that no
contamination was found above the detection level used in the
analysis.
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COMMENT: Despite assurances chat the plume would most likely
spread only in length and not in width, it was later stated that
the plume was net following the normal nodel of plume expansion.
This can only tell me Chat your agency should err en the side of
caution in this instance and assist those properties flanking the
current location of the pollution.
RESPONSE: What was stated is that the Riverview plume is not
following a 'normal' pattern or a pear shaped pattern that might
be associated with ground water contamination plumes. The
contamination plume is responding to the conditions and geologic
setting present at the site. Given the geohydrologic conditions
present and our better understanding of the ground water regime
in the area, the plume's response can be predicted. The EPA has
employed this understanding and the analytical data in the
designation of homes to be included for connection by EPA to the
city water supply. The EPA will continue to monitor the ground
water to maintain accurate information regarding the area of
contamination.
COMMENT: The commentor requests that "...a list of additional
sources of material concerning this process be made available to
the people through their inclusion to the Administrative Record
File at the Sedgwick County Health Department and that EPA
personnel experienced with this process be made available to
answer public questions."
RESPONSE: The EPA has conducted research on the use of the 'in-
well' stripper technology as part of the development of the
Riverview OU feasibility study. This information will be
available in the administrative record. In addition, EPA will
gather additional information on the implementation of this
technology as part of the remedial design phase. When the
remedial design is completed, a copy of this information will be
made available in the record and will contain specific details
concerning the activities in the Riverview OU.
COMMENT: The commentor expressed concern over the lack of medical
information and recommendations at the meeting. The commentor
expressed distress at the response concerning these issues. He
stated, "...no one can tell what this exposure might have done to
these children developmentally. Could this exposure predispose
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ihese children towards cancer in the future? The chances as we
know them at this time would argue against that outcome, but
failing to monitor the affected children cr failure to recommend
that a simple statement be entered to their medical record
documenting the exposure is an extreme oversight on your part."
RESPONSE: The ATSDR is maintaining an ongoing effort to assist
the residents and physicians to understand the health effects
that may result from exposure to the contaminated ground water.
The ATSDR has stated that the exposure to residents in the
Riverview area is thought to be of a short duration and has now
been ended or significantly reduced by the use of bottled water
and whole-house filters; and soon, with the availability of water
from the public water supply, should be virtually eliminated.
The ATSDR has also stated that it would be difficult to monitor
the effect on humans due to the very low levels of the
contaminants found in the ground water in this area.
There were several other questions and comments that did not
specifically address the actions to take place for the Riverview
OU, but were more appropriate to the final actions to take place
for the entire 57cn & N. Broadway site. These will be thoroughly
considered when the actions for the entire 57th & N. Broadway
site are proposed.
Copies of the official transcript of the April 16, 1998,
public hearing and all correspondence sent to EPA during the
comment period will be housed in the two Administrative Record
Repositories, one at 1900 E. 9-h Street in the Wichita-SedgwicJc
County Department of Public Health in Wichita, Kansas, and the
other at the US EPA Region 7 Office at 726 Minnesota Avenue in
Kansas City, Kansas.
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