United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R07-89/026
September 1989
Superfund
Record of Decision
Solid State Circuits, MO
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R07-89/026
3. Recipient's Accession No.
4. Title and Subdue
SUPERFUND RECORD OF DECISION
Solid State Circuits, MO
First Remedial Action - Final
5. Report Date
. 09/27/89
7. Author(s)
a. Performing Organization RepL No.
9. Performing Organization Name and Address
10. Project/Task/Work Unit No.
11. Contract(C) or Grant(G) No.
(C)
(C)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/000
14.
15. Supplementary Notes
16. Abstract (Limit: 200 words)
The Solid State Circuits (SSC) site, a former industrial and manufacturing facility, :
located in Republic, Missouri, approximately twelve miles southwest of Springfield. :
approximately 1/2-acre site has residential areas to the east, west, and south, and lie
industry and warehousing to the north and south. The city of Republic obtains ics
drinking water from three municipal wells (2,3, and 4) which draw from the deepest of
I three underlying aquifers. The site currently consists of a former manufacturing
kbuilding, two air strippers, and an excavated yard area (from prior removal actions).
mJses of the facility since 1902 included milling, refrigeration, printed circuit board
I manufacturing, and photoprocessing, as well as other, unknown, activities. The major
I wastes generated appear to have been cleaning solvents used in the circuit board proces
and- wastewaters from the circuit board activities. Sampling by the Missouri Department
of Natural Resources (MDNR) in 1982 revealed contamination with TCE in Municipal Well'
Number 1, 500 feet south of the site. The SSC site was identified as a possible source
Subsequent actions by MDNR, EPA, SSC, and the city included pumping tests, several majc
soil and debris excavations and removals (thereby eliminating the source of
contamination),.and taking Municipal Well Number 1 out of service. This Record of -
Decision addresses the ground water contamination found in all three aquifers.
Contamination was found in the ground water, water in utilities, and air. The primary
contaminants of concern are VOCs, particularly TCE. (See Attached Sheet)
17. Document Analysis a. Descriptors
Record of Decision - Solid State Circuits, MO
First Remedial Action - Final
Contaminated Media: gw
Key Contaminants: VOCs (TCE)
b. Identifiers/Open-Ended Terms
c. COSAT1 Reid/Group
_ 18. Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages.
78
22. Price
(See ANSI-Z39.1S)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R07-89/026
Solid State Circuits, MO
First' Remedial Action - Final
16. Abstract (continued)
The selected remedial action for this site includes ground water pumping and onsite
treatment using existing air strippers, discharging the treated water to a POTW, plume
control via pumping, and BACT (as requ.ired) for air emissions; and air and water
monitoring. The estimated present worth cost for this remedial action is 54,629,000,
which includes an annual O&M cost of $445,300.
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DECLARATION FOR THE RECORD OF DECISION
SITE NAME AND LOCATION
Solid State Circuits Site
Republic, Missouri
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action
for the Solid State Circuits Site in Republic, Missouri, chosen
in accordance with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), as amended by
the Superfund Amendments and Reauthorization Act of 1986 (SARA)
and, to the extent practicable, the National Contingency Plan, 40
C.F.R. Part 300. This decision is based on the Administrative
Record file for this site.
The State of Missouri concurs on the selected remedy. A
letter from the State of Missouri stating their concurrence is
included in this Record of Decision package.
ASSESSMENT OF THE SITE
The site has three aquifers that are contaminated with
hazardous substances, primarily trichloroethene (TCE). Estimates
of the volume of contaminated water are as follows: 15 million
gallons in the unconsolidated/fractured shallow bedrock system,
790,000 gallons in the shallow bedrock system, and 42 million
gallons in the deep bedrock system.
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
endangerroent to public health, welfare, or the environment.
DESCRIPTION OF THE REMEDY
The selected remedy addresses only the contamination of the
ground water aquifers. Previous response actions removed the
soil as a source of continuing contamination.
The major components of the selected remedy include:
Extraction of the contaminated ground water by using
existing and new wells;
Onsite treatment of the extracted ground water using
two existing air strippers;
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Discharge of, treated, water, to the City of Republic
sewer system to receive further treatment at the
Publicly Owned Treatment Works;
City ordinance to prevent construction of drinking wells
in or near the contaminant ground water plumes; and,
Continued monitoring to determine the effectiveness of
the remedy.
These response actions would prevent future ingestion/derinal
contact of hazardous subst --nces by containing the contaminated
ground water plumes, removing the contamination, and restoring
the aquifer to acceptable goals for unrestricted use.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable and appropriate to the remedial action,
and is cost effective. This remedy utilizes permanent solutions
and alternative treatment technologies to the maximum extent
practicable and satisfies the statutory preference for remedies
that employ treatment which reduce toxicity, mobility, or volume
as a principal element.
A review ,will be conducted within five years after com-
mencement of remedial action to ensure that the remedy continues
to provide adequate protection of human health and the
environment.
9- 2,7-
Date <•'' Morris Kay, Regional Administrator
Environmental Protection Agency, Region VII
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JOHN
(JWKTTUT
1 ()i
'
Divnuon 01 Miruticmciu SCTMCCJ
l>i>ii»iii wt' l*trk» KIT. ivilr.n.
a."K! Historii.- ['fc-cn-jtuifi
September 25, 1989
Mr. Morris Kay
Regional Administrator
ii.S. £PA Region VII
726 Minnesota Aver.ue
Kaneaa City, KS 661"!
^eor Mr. Kay;
Missouri Depar'iment or Natural Kedouirces *zr, reviewed the Rocord of
jec-isiori (ROD) for the soll3 store circuits, .:„•. ailc in Uepui;ilc, Missou
I^.6 depsrttner." concurs wii)i Lf:e seieeLed remedy fnr rr.n r,\tc dcta'. Joel : .- t
if you have any q-jos-ianc rag^rdir.g 'his matcar, niease so not hesitat
rjontflct r,e .
Very truly yours,
DEPARTMENT 0? NATURAL RESOURCES
^ZX-
S ^-~' . ^
'•'•}. Trary Manan, TTT
c Director
C;TM:;}SP
cc: Mr. "ofcert Morby, BFA
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RECORD OF DECISION
SOLID STATE CIRCUITS SITE
REPUBLIC, MISSOURI
Prepared by:
U.S. Environmental Protection Agency
Region VII
Kansas City, Kansas
SEPTEMBER 1989
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TABLE OF CONTENTS
SECTION PAGE
1.0 SITE NAME, LOCATION, AND DESCRIPTION 1
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 1
J.O HIGHLIGHTS OF COMMUNITY PARTICIPATION 9
4.0 SCOPE OF RESPONSE ACTION 10
5.0 SUMMARY OF SITE CHARACTERISTICS 10
6.0 SUMMARY OF SITE RISKS . 32
7.0 DESCRIPTION OF ALTERNATIVES 37
8.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF 44
ALTERNATIVES
9.0 THE SELECTED REMEDY 53
10.0 STATUTORY .DETERMINATIONS 61
APPENDIX A: CONTAMINANT SPECIFIC ARARS 66
APPENDIX B: SUMMARY OF CHEMICALS DETECTED 69
APPENDIX C: CRITERIA FOR CHARACTERIZATION OF POTENTIAL 71
CARCINOGENIC AND NONCARCINOGENIC EFFECTS
FOR THE INDICATOR CHEMICALS
APPENDIX D: POTENTIAL HUMAN HEALTH RISK SUMMARY 74
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LIST OF FIGURES-
FIGURE 1.
FIGURE 2.
FIGURE 3.
FIGURE 4.
FIGURE 5.
FIGURE 6.
FIGURE 7.
FIGURE 8.
FIGURE 9.
FIGURE 10
FIGURE 11
FIGURE 12,
FIGURE 13,
FIGURE 14,
PAGE
REGIONAL LOCATION OF REPUBLIC, MISSOURI 2
MAP OF REPUBLIC, MISSOURI 3
LOCATION OF THE REPUBLIC, MISSOURI SITE 5
BEDROCK GEOLOGIC CROSS SECTION 12
BEDROCK SURFACE CONTOUR MAP 14
GROUND WATER TCE CONCENTRATIONS-, 22
UNCONSOLIDATED/FRACTURED SHALLOW
BEDROCK SYSTEM
GROUND WATER TCE CONCENTRATIONS, 24
UNFRACTURED SHALLOW BEDROCK SYSTEM
GROUND WATER TCE CONCENTRATIONS, 26
DEEP BEDROCK SYSTEM
WATER TCE CONCENTRATIONS FROM SANITARY 29
SEWER SYSTEM
TCE CONCENTRATIONS DETECTED IN 30
SOUTHWESTERN BELL MANHOLES
ALTERNATIVE II PROCESS FLOW DIAGRAM 39
ALTERNATIVE III PROCESS FLOW DIAGRAM 42
ALTERNATIVE IV PROCESS FLOW DIAGRAM 45
PREDICTED CONCENTRATION CONTOURS FOR A TCE 57
AIR EMISSION RATE OF 34.76 MILLIGRAMS PER
SECOND AT A FLOW RATE OF 150 GALLONS PER MINUTE
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LIST OF TABLES
PAGE
TABLE 1. SUMMARY OF CHEMICAL CONSTITUENTS DETECTED
IN SOIL SAMPLES
16
TABLE 2. SUMMARY OF CHEMICAL CONSTITUENTS DETECTED
IN GROUND WATER
18
TABLE 3. SUMMARY OF CHEMICAL CONSTITUENTS DETECTED
IN WATER IN UTILITIES
23
TABLE 4. APPLICABLE OR RELEVANT AND APPROPRIATE 33
REQUIREMENTS OR HEALTH GUIDELINES FOR INDICATOR
CHEMICALS DETECTED AT THE REPUBLIC, MISSOURI SITE
TABLE 5. RELEASE SOURCE ANALYSIS AND EXPOSURE PATHWAYS
AT THE REPUBLIC, MISSOURI SITE
35
TABLE 6. FINAL GROUND WATER ALTERNATIVES
PRESENT WORTH ANALYSIS
53
TABLE 7. FINAL ALTERNATIVE II CAPITAL COSTS
59
TABLE 8. FINAL ALTERNATIVE II ANNUAL OPERATION
AND MAINTENANCE COSTS
60
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SECTION 1.0 SITE NAME. LOCATION. AND DESCRIPTION
Republic is located in southwest Missouri approximately
twelve miles southwest of Springfield, Missouri as shown on
Figure 1. The Solid State Circuits (SSC) site is located at the
southeast corner of Elm and Main streets in Republic, Greene
County, Missouri, as shown on Figure 2. Republic's 1986 popula-
tion was estimated at 6,139 with a projected population of great-
er than 10,000 by the year 2005.
Currently, the SEZ site is a lot of approximately 21,000
square feet (1/2 acre) enclosed within a six foot high chain link
fence. The only permanent building currently on the lot house's
two air stripper towers. The surrounding land use is urban.
Single family dwellings exist to the east and two blocks to the
west and south. Light industry and warehousing exists due south
and north of the site. The City of Republic obtains its drinking
water from three municipal wells drawing from the deep bedrock
aquifer. Municipal Well Number 2 is approximately 2,100 feet
east-southeast of the site, Municipal Well Number 3 is 4,900 feet
northeast of the site, and Municipal Well Number 4 is 4,700 feet
west of the site. Municipal Well Number 1, not in service, is
approximately 500 feet south of the site. The location of the
site to the municipal wells is shown on Figure 2.
SECTION 2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1 Site History
The SSC site is a former industrial and manufacturing site
which was leased and operated by a number of business concerns
through the years. The former plant building apparently was
constructed prior to 1902 and was originally operated by a
milling company. Based on a review of historical photos, the
building extended the entire length of the block from Mill to Elm
Street. The building was one story except for the northern
third, which was four stories high. Sometime between 1902 and
1937, a cold (refrigeration) plant began operations in the
building, at least in its northern end. From the period of 1930
to 1968, lictle is known about specific uses of the former plant
building and land, or what chemicals may have been used.
Solid State Circuits, Inc. (SSC) began manufacturing opera-
tions in the northern end of the building in 1968 and continued
until November, 1973. SSC manufactured printed circuit boards in
the plant, and used trichloroethene (TCE) as a cleaning solvent
in portions of its manufacturing process. Reliable volume
estimates of TCE and other chemicals used at the site are not
available. The SSC plant waste water reportedly contained copper,
chromium, iron, ammonium, manganese, and zinc; however, the
reliability of this information is not known. Wastes were
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vgr-jV - py >fef«fa/*r^rrr•»? /-.. Tv.n.
ic. Mo Ste _
Well .--j.^.l y-
REGIONAL LOCATION OF REPUBLIC, MISSOURI
FIGURE -1
2
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Main Street
I
Location of
Republic, Missouri
I Missouri
= = Highw»y 171
4°
Raifroad
0 500 150n
—rv-^Fv' rionj
= = RepubiJc City Lime
County Road
3000 feet
jMAP OF REPUBLIC, MISSOURI
O OV- _ Municipal '.Veil
»Cave Well
M Roberts Spring
FIGURE 2
3
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reported to have been temporarily stored in a sump pit in the
basement. A capped well was also located in the basement, which
may have served the city as a water supply.
In November 1973, SSC moved its manufacturing operations to
Springfield, Missouri. The SSC site was occupied thereafter by
Micrographics, Inc., a photographic processing firm, and possibly
other businesses until 1979. Micrographics, Inc. occupied the
northern end of the building. Other businesses which may have
operated on the premises and the chemicals they may have used
could.not be determined. In November 1979, the northern part of
the building was destroyed by fire. Some witnesses have stated
that' the basement had a strange odor and everything appeared
green and corroded prior, to.the fire. During the fire, other
witnesses stated they saw several fifty-five gallon drums in the
basement; however, investigative excavation did not confirm this.
After the fire, the damaged portion of the structure was
demolished and the debris pushed into the basement under the
remaining portion of the building. The vacant lot was -sed for
parking occasionally.
Mr. Nicholas Weinsaft purchased the former SSC property in
1976. Currently, the remaining southern portion of the building
and the vacant lot are owned by Crane Manufacturing Company of
Crane, Missouri (see Figure 3). The only known tenant of the.
southern portion of the building is a factory outlet store.
2.2 Removal History
In June 1982, the Missouri Department of Natural Resources
collected samples from the City of Republic's three municipal
wells for analysis of volatile organic compounds as part of EPA's
National Synthetic Organic Chemical Survey. A TCE. level of 15
micrograms per liter (ug/1) was detected in Republic's Municipal
Well Number 1, which is located 500 feet south of the former SSC
manufacturing site. The detected concentration was below
Missouri's health based criteria, at that time, of 27 ug/1 in
drinking water. Additional sampling by MDNR confirmed the
presence of TCE in this well, and it w^s taken out of service
sometime between July 1983 and March 1984. The exact date is not
known. Municipal Wells Numbers 2 and 3 were not contaminated
with volatile organic compounds and have remained so to the
present. Municipal Well Number 4 was brought on-line in 1988,
and it also has been sampled and found to be uncontaminated by
volatile organic compounds. MDNR collected and analyzed samples
from the three uncontaminated municipal wells on a monthly basis
throughout the remedial investigation and the feasibility study.
In April, 1983, MDNR initiated response actions to identify
possible contaminant sources and to further investigate the TCE
occurrence in Municipal Well Number 1. The former SSC manufac-
turing plant was identified as one potential source of the TCE.
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LOCATION OF THE REPUBLIC, MISSOURI SITE
@ Former Plant. Building
Q Existing One-Story Building
C_j Former Extent of One-Story Building
Prepared for: Solid State Circuits, Inc.
Project Manager: Steven D. Chat.-nan
Geraghty & Miller, Inc.
Figure
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In 1984, MDNR. conducted response activities-at the SSC site;
the-activities were divided into four separate phases. During
Phase I, MDNR sampled Roberts Spring, a local well designated as
Cave Well, and Municipal Well Numbers 2 and 3, and pumped
Municipal Well Number 1 for 10 days and collected samples from
the well. During continued pumping of Municipal Well Number 1,
the TCE concentration decreased within a five day period from 140
ug/1 to 25 ug/1. TCE was detected in the samples from Municipal
Well Number 1 only.
During Phase II, SSC financed the excavation of approxi-
mately 1,500 cubic yards1 of soil and. debris from the former
building basement area and conducted extensive soil and water
sampling in and around the basement area. During the excavation,
only three containers were discovered. There was one crushed
fifty-five, gallon drum, an empty crushed five gallon can, and a
cracked thirty gallon cylinder. Additional features discovered
in the basement area were an old basement well about 540 feet
deep, an elevator shaft, a sump of unknown function, and a sewer
box. TCE was found in samples of the fill dirt and rubble exca-
vated from the basement, in water from the basement, in the
shallow ground water outside the basement area, and in ground
water samples taken at various depths in the 540-foot well.
Approximately 75 to 150 cubic yards of excavated soil and debris
were transported from the site and disposed at Bob's Home Service
in Wright City, Missouri. The remaining soil, somewhere between
1,325 and 1,425 cubic yards, was temporarily stored on.site.
During Phase III, MDNR pumped Municipal Well Number 1 for
24 hours to monitor its effect on the basement well and an
offsite monitoring well, but the results were inconclusive. Two
ground water samples were collected from. Municipal Well Number 1.
During Phase IV, SSC financed additional excavation and
sampling beneath the basement floor and installed three shallow
monitoring wells. Several sub-basement pipes were encountered:
a cast iron pipe, a metal lined concrete culvert, and a clay tile
pipe. The basement well had two holes in the casing at depths of
four and eight feet beneath the basement. The basement well
appeared to receive recharge water from the surface drainage
system, specifically from the clay tile pipe. Samples showed
continued high levels of TCE in the SSC basement well, the shal-
low ground water, and the soil beneath the site. From October to
November, 1984, MDNR cleaned out the basement well, recased it tc
a depth of.40 feet, and installed a submersible pump. Due to a
poor recharge flow of 0.75 gallons per minute, the veil was
determined to be a poor candidate for use in recovering
contaminated ground water.
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On April 5, 1985, the EPA Regional Administrator signed an
Action Memorandum which allowed EPA to undertake an immediate
removal at the site. These activities were undertaken to
mitigate the potential threat to the public health and the
environment posed by the approximately 1,400 cubic yards of
contaminated soil that remained on site. The actual removal
action began on April 18, 1985. Samples were taken of the
stockpiled soil and of the entire site area to define any
additional areas requiring excavation. Additional excavation of
the basement area occurred from late April to mid-May, 1985.
Excavation of soil was most extensive in the southern portion of
the basement where TCE concentrations were found to be the
highest. Excavation was terminated when bedrock was encountered.
Approximately 800 cubic yards of contaminated soil was removed
from beneath the basement floor. Four new shallow offsite
monitoring wells were installed from May 6 to May 8, 1985.
Site operations were suspended from May 17 to August 27,
1985 when it was discovered that the original disposal facility
for the contaminated soil was not in compliance with Resource
Conservation and Recovery Act (RCRA) requirements. In time, a
suitable disposal site was selected, and approximately 1,990 tons
of contaminated soil and debris was disposed at the Adams Center
Landfill near Fort Wayne, Indiana. Transport of contaminated
soil began on September 4 and was completed on October 3, 1985.
In addition to the soil removal activities, two recovery/
monitoring wells were installed onsite in October. One well,
completed at a depth of 331 feet (designated REM-2), was con-
structed on the west side of the site within the perimeter of the
former basement area to monitor the shallow bedrock aquifer. A
second well,.completed at a depth of 600 feet (designated REM-1),
was constructed on the east side of the site outside the perime-
ter of the former basement area to monitor the deep bedrock
aquifer. Pumps were installed in both wells on October 30, 1985.
The old basement well was sealed. The excavated basement area
was filled with 85 tons of gravel forming a one foot layer. A
sufficient quantity of clean fill dirt was then placed over the
gravel to bring the excavated area up to grade. The wooden fence
around the site was replaced with a chain-link fence to improve
site security, and final grading and seeding of the area took
place on October 31, 1985.
On October. 7, 1985, MDNR announced that they would be
assuming long-term responsibility for the remedial cleanup of the
SSC site. The EPA placed the site on the National Priorities
List (NPL) on June 10, 1986.
2.3 Enforcement History
On June 15., 1983, MDNR notified all known potentially
responsible parties (PRPs) of the problem existing in Republic
and invited them to a meeting to discuss voluntary remediation of
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the site. On December 2, 1983, MDNR sent Notices of Imminent'
Hazard to the potentially responsible parties. On December 14,
1983, SSC and Paradyne, who had not been notified as PRPs, stated
that they had retained the services of a nationally recognized
ground water company to perform a preliminary study of the
problem.
On August 26, 1983, MDNR notified che property owner,
Mr. Nicholas Weinsaft, that the site was proposed for inclusion
on the Registry of Confirmed Abandoned or Uncontrolled Hazardous
Waste Disposal Sites in Missouri. On September 15, 1983, the
property owner appealed the listing on the basis that he wished
to either delete the property from the Registry or decrease the
size to be included on the Registry. The MDNR and Mr. Weinsaft
reached an agreement on October 22, 1984, concerning the property
to be placed on the Registry. The Registry would not include
property still in use by Mr. Weinsaft. The property to be
included was located immediately adjacent to and against the
north wall of the building owned by Mr. Weinsaft. The SSC site
was placed on the Registry on February 22, 1985.
On January 25, 1985, the EPA issued a letter to the PRPs
informing them of their intent to issue an Administrative Order
to include response actions to abate the threat posed by the
site. Alternatively, PRPs: could enter into an Administrative
Order on Consent with EPA to perform the necessary cleanup work.
On March 6, 1985, the EPA Regional Administrator issued a CERCLA
106 Administrative Order to identified responsible parties. SSC
and Paradyne contested the Administrative Order. However, on
March 14, 1985 a federal judge ruled in favor of EPA. EPA
approved the Action Memorandum on April 5, 1985 'for an immediate
removal. On March 1, 1988, SSC settled with EPA in the amount of
$945,000, for costs incurred by the United States when SSC failed
to respond to EPA's March 6, 1985 Administrative Order.
On February 25, 1985, the Attorney General's Office of the
State of Missouri sent letters to all of the known PRPs demanding
payment plus interest of the money expended by the state for
response actions at the SSC site and offering them the
opportunity to voluntarily take action to abate any releases or
threatened releases from the facility. On April 30, 1985, the
MDNR filed a civil action pursuant to CERCLA 107 (a) and Missouri
common law of public nuisance to 1) recover monies expended by
the state at the SSC site, 2) seek recovery of future costs of
remedial action at the site incurred by the state, and 3) seek
damages for injury to natural resources of the State of Missouri.
On May 28, 1985, SSC filed its Answer and Counterclaim against
the state contending that the state should also be responsible
for the TCE contamination since SSC allegedly had sought the
advice of the Missouri Clean Water Commission on TCE disposal.
On February 5, 1986, the Attorney General's Office notified three
additional PRPs of their liability in regard to the state monies
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expended at the site and offered them the same, opportunity to
take voluntary action. On May 15, 1986, the MDNR and Solid State
Circuits reached a settlement for past costs.
Following the April 30, 1985, civil action filed by the
state, the MDNR and SSC entered into settlement negotiations. On
November 20, 1986, MDNR entered into a partial consent decree on
certain issues with SSC. SSC agreed to perform the remedial
investigation/feasibility study (RI/FS), but left open the issue
of liability for future costs, the state's determination of the
total damages for alleged natural resources damage, and SSC's
counterclaim against the state. SSC agreed to pay oversight
costs to the MDNR to see that the RI/FS was implemented according
to the approved work plan. On December 18, 1985, SSC submitted a
plan to MDNR to conduct the RI/FS at the site. The RI/FS work
plan was resubmitted in June 1986 in response to MDNR and EPA
comments. After additional review and comment, MDNR/EPA approved
the work plan in December, 1986. Implementation of initial RI
activities began in late December, 1986, soon after approval,
with the development of site investigation documents. SSC began
field work for the RI/FS in June, 1987.
SECTION 3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
The RI/FS and Proposed Plan for the Solid State Circuits
site were released to the public on August 14, 1989. The
administrative record file, which included the RI/FS reports and
the Proposed Plan, was made available to the public at informa-
tion repositories maintained at the Missouri Department of
Natural Resources, in Jefferson City, the EPA Docket Room, in
Kansas City, Kansas, and the Greene County Library -
Republic Branch. The notice of availability for these documents
was published in the Republic Monitor and the Springfield
News-Leader on August 10, 1989. A public comment period was held
from August 14, 1989 through September 5, 1989. In addition, a
public meeting was held on August 24, 1989. At this meeting,
representatives from the Missouri Department of Natural Resources
(MDNR) and EPA answered questions about problems at the site and
the remedial alternatives under consideration. At. the meeting,
citizens requested an extension of the public comment period. In
response, MDNR and EPA extended the comment period through
September 14, 1989 to allow citizens additional time to review
the administrative record and the Proposed Plan. A response to
the comments received during this period is included in the
Responsiveness Summary, which is part of this Record of Decision.
This decision document, presents the selected remedial action
for the Solid State Circuits Site, in Republic, Missouri, chosen
in accordance with CERCLA, as amended by SARA and, to the extent
practicable, the National Contingency Plan. The decision for
this site is based on the Administrative Record.
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SECTION 4.0 SCOPE OF RESPONSE ACTION
To address the potential risks, the following remedial
action objectives were identified for all three ground water
aquifers:
* Prevent potential exposure to contaminated ground water;
* Protect uncontaminated ground water for future use by
preventing further migration of the contaminated ground
water plumes; and,
* Restore contaminated ground water for future use by
reducing the contaminant concentrations to regulated or
health-based levels.
SECTION 5.0. SUMMARY OF SITE CHARACTERISTICS
The Remedial Investigation (RI) field work, conducted by the
PRP under MDNR oversight from mid 1987 to early 1989, included
the following activities to define the types of contaminants at
the site, potential routes of contaminant migration and routes of
exposure, population and environmental areas that could be
affected, and site-specific factors that may affect the remedial
actions at the site:
Sampling and analyses of onsite and offsite air,
soil, surface water, utility water, and ground water;
Installation of a network of monitoring wells into
three hydrologic units: shallow unconsolidated/
fractured bedrock, shallow bedrock, and deep bedrock/-
Definition of a fracture zone in the bedrock through
utilization of borehole and surface geophysical
techniques;
Performance of detailed slug tests, packer tests, and
aquifer tests;
Detailed monitoring and analyses of ground water levels
and ground water chemistry in the area;
Detailed monitoring and analyses of water samples from
the Publicly Owned Treatment Works (POTW), sewer
system, and Southwestern Bell manholes;
Detailed analyses of site and municipal ground water
pumpage;
Partial implementation of a pilot program to treat
contaminated ground waters;
10
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Development and implementation of numerical
ground water flow and air flow models to assess past
and present ground water flow directions and the
possible dispersion of airborne contaminants,
respectively;
Completion of an offsite survey of private wells in
the vicinity of the site; and,
Air sampling and analyses in offsite, nearby
residential basements.
Several types of contamination - volatile organic compounds
(VOCs), organic compounds, and metals - were found during the RI
in varying-concentrations and in various media including ground
water, water in utilities, surface soils, subsurface soils,
and air both in utilities and above ground. The elevated
concentrations of certain VOCs in the subsurface soils and
ground water beneath the site indicate that a release of
chemicals occurred at the site. The following section presents
the results, conclusions and recommendations of the RI.
Tables and diagrams presented in this section are either
derived in part or entirely duplicated from the RI report written
by Geraghty & Miller, Inc. for Solid States Circuits, Inc.
Trichloroethene (TCE), a. VOC, was the most common contaminant
detected in all media types; other contaminants were detected at
much lower frequencies and concentrations. For this reason,
diagrams will be based on TCE concentrations.
5.1 HYDROGEOLOGIC SETTING
A sequence of three hydrologic units is known to exist
beneath and near the site: 1) the unconsolidated/fractured
bedrock system (UFSB), 2) the unfractured shallow bedrock system
(SBR), and 3) the deep bedrock system (DBR). Figure 4 pictori-
ally presents the site and local hydrogeology.
Republic lies within the Springfield-Salem Plateau sections
of the Ozark Plateaus physiographic province, interior Highlands
Division. Rocks of Mississippian Age underlie most of the re-
gion. The Mississippian Formations are generally coarse crystal-
line limestone which contain discontinuous beds of chert.
The upper portion of these formations has been intensely
weathered, resulting in an overlying residuum layer of silt,
clay, and chert fragments. The UFSB unit is this overlying layer
and is shown on Figure 4 as the thin layer above bedrock. This
unit is approximately twenty feet thick. The UFSB is not
important as a regional aquifer.
11
-------
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1200
1100
_ 1000
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5 800
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200'
100'
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-200-
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Top of Bedroclc
Upper Aquifer Ntisaiappian
.*4^rrhv-iVw «:ha!*
i
Cotter it Jefferson City Formations
^ . • —
Roubidoux Dolomite
— .^.--^ichiand Sandstone
p ' —
Gasconade
Gumer Sandstone j
Eminence Dolomite
~~ • '
Derby-Doerun,
Dtvis, Bonneterre
Undifferennated
BEDROCK GEOLOGIC CROSS SECTION K-L
I Casing
Open Borehole
FIGURE 4
12
-------
Ground water flow in the UFSB is in the same general direc-
tion as surface water runoff or flow, unless influenced by other
local features such as fracturing. Two fractured bedrock lows in
the upper part of the shallow bedrock were identified during the
RI. One originates northeast of the site and runs beneath the
site as it swings in a broad arc crossing Main Street south of
the site, recrossing Main Street, and then trends south-southeast
toward U.S. Highway 60. The second narrow bedrock surface low
trends east-southeast towards Main Street and intersects the
other low near U.S. Highway 60. The saturated thickness of the
UFSB decreases from approximately 15 feet at the site to less
than a foot near U.S. Highway 60. This pattern reflects that a.
strong fracture is acting as a ground water sink. Figure 5 shows
the locations and trends of the narrow bedrock lows.
The SBR unit is the minor aquifer consisting primarily of
deeply weathered, cherty limestone and residuum overlying the
Northview Formation. On Figure 3, the SBR unit extends
approximately 270 feet from the UFSB to the Northview Shale
formation. The SBR and perhaps deeper bedrock units regionally
can have fractures or joints which can significantly impact the
flow of ground water and transport of contaminants. In regions
where weathering has reached a high degree of maturity, the area
is termed a "karst" region characterized by sinkholes, caves,
springs, and losing streams. Based on information gained during
construction of the bedrock monitoring wells, the SBR exhibited
an unfractured and unweathered physical character, indicating a
limited potential for the existence of fractures locally.
Ground water flows in a southeasterly direction during
static conditions in the SBR. Pumping of Municipal Well-No. 1
effectively contains the ground water around the site.
The top of the Northview Formation is approximately 290 feet
below the ground surface at the site. The Northview Formation is
a confining layer composed of siltstone and shale and having an
estimated vertical permeability of 0.000000001 (1 x 10 ) to
0.000001 (1 x 10~6) feet per second. This Northview shale acts
as a confining bed restricting flow between the SBR and D3R.
The DBR unit is the major aquifer in the area and the one
used for the City of Republic's drinking water source. Large
quantities of ground water are withdrawn from the major aquifer
by wells in and around Springfield. The DBR unit is confined
beneath the Northview Formation and consists of a dolomite
sequence, primarily the Jefferson City-Cotter Formations. A
major portion of recharge to the DBR comes from water leaking
downward through the overlying material, or from recharge
directly from infiltration where it is exposed to the land
surface. The closest outcrop to the site is about four miles
east. . Ground water elevations in the major aquifer are from 100
to 300 feet lower in elevation than ground water elevations in
13
-------
BEDROCK SURFACE CONTOUR MAP
Contour. Interval-5'
E SSC-_Shal!o* Bedrock Morutoring Well
• SSC-_Deep Bedrock Monitoring Well
A REM-_Recovery Well
O CW-_\(unicipal Well
FIGURE 5
i:80.7-Bedrock Elevation in Peer above Mean Sea Lf-'tl
SSC-_Shallow L'nconsolidated Monitoring Well tRP
MW-_Shallow L'nconsolidated Monitoring Weil (Pre-RI;
Cive Well
14
-------
the minor aquifer due to ground water pumpage in the major
aquifer. Increased drawdown in the DBR has the potential of
increasing the recharge through the overlying material.
Contaminants entering the shallow aquifer can. potentially migrate
to the DBR either by natural leakage through the Northview
Formation, or by seepage into and down improperly constructed
water wells, or along fractures or faults that penetrate this
confining formation.
Ground water flow in the DBR within Republic is controlled
by the city's well system. With Municipal Well Number 1 off,
ground water from the site flows toward Municipal Well Number 2.
Pumping Municipal Well Number 1 effectively contains ground water
in and around the site.
5 . 2 Source Characteristics
The response actions undertaken by MDNR/SSC and EPA removed
any immediate sources in the form of contaminated soils from the
basement area. This is confirmed by analyses of RI data which
indicate that TCE concentrations in ground water are greater than
TCE concentrations found in onsite, subsurface soils. Ground
water is the current source of contamination detected in the
soils, as explained in the following Soils and Ground Water
subsections.
5.3 Surface Water
The RI surface water investigation concluded that Roberts
Spring and Shuyler Creek were the most likely bodies of surface
water to be impacted by the site. Since Shuyler Creek is dry
most of the year, Roberts Spring was sampled. No contaminants
related to the site were found in the surface water samples
collected at Roberts Spring.
5.4 Soils
Table 1 presents a list of contaminants round in surface or
subsurface soils and presents the frequency of occurrence,
maximum and average concentrations, and location of maximum
concentration for each contaminant identified.
Onsite surface soils contain VOCs at relatively low concen-
trations. The relatively high concentrations shown in Table 1
for benzene, 1,1-dichloroethene and methylene chloride are not
true soil concentrations. Instead, these concentrations were
obtained from samples of the air (or headspace) above the soil
inside the soil sample jar. Actually, these results are a better
indication of soil gas concentrations. Given the high concentra-
tions of VOCs known, in shallow ground water, the soil gas concen-
trations were not unexpected.
15
-------
TABLE 1. SUMMARY OP CHEMICAL CONSTITUENTS DETECTED IN SOIL SAMPLES
CONSTITUENT
• ••••tf*«»*MM«*«a
BENZENE
NO. DETEC1ED/
NO. ANALYZED
MAXIMUM/AVERAGE(1) MAXIMUM
CONCENTRATION CONCENTRATION
9/88
7/80
3/80
9/88
1/80
9/88
5/88
8/80
TRANS-1,2-DICHLOROETHENE 5/72
1,1,1-TRICHLOROETHANE 10/80
1,1,2-TRICHLOROTHANE
CHLOROFORM
1,1-DICHLOROETHANE
1,1-DICHLOROETHENE
ETHYLBENZENE
METHYLENE CHLORIDE
TETRACHLOROETHENE
TOLUENE
TRICHLOROETHENE
VINYL CHLORIDE
3/80
30/80
3/80
(UG/KG)
460/ (2)
55
IV
5.3
20/
13
11,000/ (2)
3, 607
2.6/
2 . 6
2,700/ (2)
319
69/
40.2
7.8/
5.2
ISO/ .
42 .4
HO/
27. 1
5.7/
4.4
4,200/
.313
3.7/
3.3
LOCATION
ONSITE
SURFACE
OFFSITE
SUBSURFACE
ONSITE
SUBSURFACE
ONSITE •
SURFACE •'
OFFSITE
SURFACE
ONSITE
SURFACE
ONSITE .
SURFACE
OFFSITE
SURF.- ~E
ONSITE -
SUBSURFACE
ONSITE
SUBSURFACE
ONSITE
SUBSURFACE
ONSITE
SUBSURFACE
ONSITE
SUBSURFACE
(1) AVERAGE CONCENTRATION IS CALCULATED USING ONLY SAMPLES IN
WHICH THE CONSTITUENT IS DETECTED. FOR EXAMPLE, ETHYLBENZENE
WAS FOUND IN ONLY ONE OF EIGHTY SAMPLES, HOWEVER THE
AVERAGE CONCENTRATION IS BASED ON THAT ONE POSITIVE RESULT.
(2) COMPOUND QUALITATIVELY IDENTIFIED BY PORTABLE GC;
SAMPLE TAKEN FROM HEADSPACE IN SAMPLE' JAR.
16
-------
Onsite VOC concentrations are less than 150 micrograms per
kilogram (ug/kg, or commonly referred to as parts per billion -
ppb) to a depth of five to twelve feet below land surface. VOC
concentrations increase with depth with the greatest concentra-
tions near the bedrock surface approximately twenty-five feet
below the ground surface. The highest onsite subsurface soil TCE
concentrations, up to 4,200 ug/kg, are found in the southern part
of the former basement area and in the five to ten feet above the
top of bedrock. As it will be shown, VOCs in the ground water
are at least five times higher than the concentrations reported
in the soil, indicating that the VOCs in the ground water are the
source for the VOCs in the soil. Earlier removal actions by
MDNR/SSC and EPA had eliminated the most contaminated, onsite
surface and subsurface soils as a source for the continued
release of VOCs.
RI activities identified very low levels of VOCs in offsite
surface soils. In fact, the detected concentrations barely
exceed analytical detection levels and are not a concern at these
concentrations. Offsite subsurface soil contamination is limited
to the fracture zone along Main Street. The maximum reported TCE
concentrations in offsite subsurface soil along Main Street was
340 ug/kg from a depth of 11 to 17.5 feet below land surface.
The maximum TCE concentration identified in offsite, subsurface
soils away from Main Street is 24 ug/kg.
Soil samples were analyzed for VOCs only and not for other
organic*or metal contaminants. Since VOCs are very mobile, VOCs
analysis was used to indicate the extent of soil contamination.
5.5 GROUND WATER
As described earlier, a sequence of three hydrologic units
is known to exist beneath and near the site: 1) the unconsoli-
dated/fractured bedrock system (UFSB), 2) the unfractured shallow
bedrock system (SBR), and 3) the deep bedrock system (DBR).
Table 2 presents a summary of the frequency of occurrence, maxi-
mum and average concentrations, and location of maximum concen-
tration for each contaminant detected in ground water.
5.6 UFSB UNIT
The UFSB is composed of two units: uncpnsolidated residual
soils and the upper portion of the bedrock that exhibits a high
degree of weathering or fracturing. The vertical fracturing
appears to be limited to depths of less than 100 feet in the
upper bedrock.
17
-------
TABLE 2. SUMMARY OP CHEMICAL CONSTITUENTS DETECTED IN GROUND WATER
CONSTITUENT
METALS
CADMIUM
CHROMIUM
COPPER
IRON
LEAD
-MAGNESIUM"
MANGANESE
MERCURY
NICKEL
ZINC
MAXIMUM/AVERAGE(1) MAXIMUM
NO. DETECTED/ CONCENTRATION CONCENTRATION
NO. ANALY2ED (UG/L) LOCATION
1/35'
1/35
15/54
39/91
2/35
91/91
22/48
9/35
3/35
18/33
2 I/
21
190/
190
55/
19. 3
47,700/
5, 300
34, OOO/
13,200
32,900/
5, 230
0.2/
0.2
80/
70
3,770/
491
ONSITE
SBR
ONSITE
SBR
REPUBLIC
DRINKING
WATER
ONSITE
UFSB
OFFSITE
UFSB •
OFFSITE
UFSB
OFFSITE
UFSB
ONSITE
DBR
ONSITE
SBR
ONSITE
SBR
(1) AVERAGE CONCENTRATION IS CALCULATED USING ONLY SAMPLES IN
WHICH THE CONSTITUENT IS DETECTED. FOR EXAMPLE, CADMIUM
WAS FOUND IN ONLY ONE OF THIRTY-FIVE SAMPLES, HOWEVER THE
AVERAGE CONCENTRATION IS BASED ON THAT ONE POSITIVE RESULT,
18
-------
TABLE 2. SUMMARY OP CHEMICAL CONSTITUENTS DETECTED IN GROUND WATER
NO. DETECTED/
NO. ANALYZED
MAXIMUM/AVERAGE(1) MAXIMUM
CONCENTRATION CONCENTRATION
CONSTITUENT
VOLATILE ORGANICS
ACROLEIN 1/97
BENZENE 6/201
CARBON TETRACHLORIDE 1/201
CHLOROBENZENE 6/202
CHLOROETHANE 1/191
CHLOROFORM • 7/202
1,1-DICHLOROETHANE 48/202
1,2-DICHLOROETHANE 4/202
1,1-DICHLOROETHENE 43/203
1,2-DICHLOROPROPANE 1/201
1,3-DICHLOROPROPYLENE 1/99
ETHYLBENZENE 6/201
(UG/L)
43/
43
4 .8
2.9
32/
32
5.7
6.3/
6.3
12/
6.2
890/
95. 3
44/
• 13.7
1000/
114 . 2
V
4
7. I/
7. 1
16/
7. 3
LOCATION
REPUBLIC
DRINKING
WATER
ONSITE
SBR
ONSITE.
DBR
ONSITE
SBR
ONSITE
SBR
ONSITE
SBR
ONSITE
SBR
OFFSITE
UFSB
ONSITE
SBR
OFFSITE
UFSB
ONSITE
SBR
ONSITE
SBR
(1) AVERAGE CONCENTRATION IS CALCULATED USING ONLY SAMPLES IN
WHICH THE CONSTITUENT IS DETECTED. FOR EXAMPLE, ACROLEIN
WAS FOUND IN ONLY ONE OF NINETY-SEVEN SAMPLES, HOWEVER THE
AVERAGE CONCENTRATION IS BASED ON THAT ONE POSITIVE RESULT.
19
-------
TABLE 2. SUMMARY OP CHEMICAL^CONSTITUENTS DETECTED IN GROUND WATER
NO. DETECTED/
MAXIMUM/AVERAGE(1) MAXIMUM
CONCENTRATION CONCENTRATION
CONSTITUENT NO.
VOLATILE ORGANICS
METK.L CHLORIDE
MET.HYLENE CHLORIDE
TETRACHLOROETHENE
TOLUENE
TRANS-1 , 2-DICHLOROETHENE
1,1, 1-TRICHLOROETHANE
1,1, 2-TRICHLOROETHANE
TRICHLOROETHENE
VINYL CHLORIDE
ACETONE
2-BUTANONE
CARBON DISULFIDE
1 , 2.-DICHLOROETHYLENE
ANALYZED
2/191
36/2.03
11/203
26/203
15/147
43/203
8/202
137/201
27/192
1/22
1/20
. 1/20
. 7/55
(UG/L)
27/
15/1
4300/
466. 1
ISO/
44. 9
1500/
221.7
3100/
343.5
14,000/
1123 . 1.
35.5
290, OOO/
11, 623
410/
27. 1
8 I/
81
25/
25
12/
12
210/
104 .4
LOCATIOK
OFFSITE
UFSB
ONS-ITE
SBR
ONSITE
SBR
ONSITE
SBR
ONSITE
SBR
ONSITE
SBR
. ONSITE
SBR
ONSITE
SBR
ONSITE.
UFSB
ONSITE
DBR
OFFSITE
UFSB
OFFSITE
UFSB .
ONSITE
DBR
(1) AVERAGE CONCENTRATION IS CALCULATED USING ONLY SAMPLES IN
WHICH THE CONSTITUENT IS DETECTED. FOR EXAMPLE, ACETONE
WAS FOUND IN ONLY ONE OF TWENTY SAMPLES, HOWEVER THE
AVERAGE CONCENTRATION IS BASED ON THAT ONE POSITIVE RESULT.
2.0
-------
The TCE plume is defined as shown in Figure 6. Ground water
flow in the UFSB near the site is controlled by a fracture zone
defined along Main Street (Figure 5). The VOC contamination is
restricted to a narrow area, less than 50 feet wide and greater
than 10 feet below land surface, south of the site along Main
Street. The highest concentrations occur at the top of bedrock
and/or in the fracture zone. Concentrations decrease with depth
in the bedrock below the fracture zone.
Outside of the fracture zone, VOC concentrations decrease
dramatically and the depth to water increases significantly,
indicating that flow and contaminant transport is along the
fracture and downward into the bedrock. South of Highway 60, the
specific location of the fracture is not well defined. The
extent of contaminants should also be restricted to a zone
surrounding the fracture at a depth of greater than 10 to 15 feet
below land surface. The direction of ground water flow and
contaminant transport should be in a south-southeast direction
toward Shuyler Creek.
In the UFSB, the TCE concentrations in ground water range
from less than 300 ug/1 (ppb) near Highway 60 to 40,000 ug/1
onsite. Municipal Well Number 1 is the approximate midway point
between the site and Highway 60. At Municipal Well No. 1, the
TCE concentration in ground water ranges from 2,000 ug/1 to 7,000
ug/1.
Except for zinc, offsite and onsite UFSB inorganic water
quality is representative of background conditions. Zinc was
detected in one offsite well and two onsite wells with a maximum
concentration of 90 ug/1. No instances of inorganic constituents
attributable to the site exceed Federal or Missouri drinking
water and Missouri water quality standards.
Several volatile organic constituents were detected in
concentrations exceeding Federal or Missouri drinking water and
Missouri water quality standards. Appendix A presents a list of
the pertinent Federal and Missouri drinking -and Missouri water
quality standards. For example, the Federal and Missouri
drinking water standard for TCE is 5 ug/1.
The estimated probable pumping race for the UFSB ranges
from 6 to less than 15 gallons per minute. There is estimated to
be over 15 million gallons of contaminated water.
The pathway along which contaminants have migrated is clear
and can be defined based on TCE concentrations, ground water flov
directions, and top of bedrock elevations. The chemicals have
migrated approximately 1500 feet south of the site. The ultimate
discharge point for the UFSB appears to be the system of caves
below Shuvler Creek.
21
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GROUND-WATER TCE CONCENTRATIONS, UNCONSOLID.
FRACTURED SHALLOW BEDROCK-SYSTEM (UFSB)
NO Not Detected Above Method Detection Limit The TCE Concentration Shown is the vfaximum Reported Value for
C SSC-_ShaIlow Bedrock Monitoring Well All Sampling Events
• SSC-_Deep Bedrock Monitoring Well C SSC-_ShalIow Unconsolidated Monitoring. Well-( RD
A REM-_Recovery Well • MW-_Shallow Unconsolidated Monitoring Well (Pre-RD
C CW-_Murucipar Weil X Cive Well
FIGURE 6
22
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5.7 SBR UNIT
The SBR system consists of the bedrock units away from Main
Street, between the top of the unweathered bedrock to the top of
the Northview shale, generally between depths of 20 to 300 feet
below land surface.. Figure 7 illustrates the horizontal distri-
bution of the TCE plume as defined by the RI sampling of the SBR
wells. The Main Street fracture zone also impacts the distribu-
tion of VOCs in the SBR as shown in Figure 7. Offsite SBR TCE
concentrations decrease with depth in the bedrock below and away
from the fracture zone. TCE was detected at concentrations
greater than 170 ug/1 in well SSC-3A, the only SBR well along
Main Street and located less than 20 feet from the defined
fracture. It is believed that the TCE in SSC-3A is related to
contaminants that have migrated along the Main Street fracture.
Onsite, the maximum TCE concentration reported was 290,000
ug/1. In general, the highest reported VOC concentrations occur
onsite in the SBR between 150 and 300 feet below land surface.
Cadmium, chromium, copper, lead, mercury, nickel and zinc
were reported above detection levels in onsite SBR wells. Zinc
was reported above detection levels in six of six samples and
nickel in three of six samples. All other metals were reported
above detection levels only once in six samples. Chromium was
detected in one sample at a concentration above the Federal and
Missouri drinking water standards. The single occurrence of
chromium was the only value for chromium reported above a
detection level during RI sampling activities. No metals were
detected above the detection level from any offsite SBR wells
along Main Street.
Although Cave Well is a karst feature, it is not believed to
have a direct hydrologic connection to the Main Street fracture
and was sampled as part of the SBR system. A TCE concentration
of 2.6 ug/1 was reported in one sample collected from Cave Well,
while a previous sample reported TCE below the detection limit of
2.0 ug/1. Zinc and mercury were detected in Cave Well at 0.02
ug/1 and 0.0001 ug/1, respectively.
Documented hydrogeologic parameters for the shallow bedroc;-
indicate a limited potential for the movement of contaminants.
In the SBR, the average ground water velocity is 0.0009 feet/day
or 3.35 feet per year. It is estimated that from 1968 to the
present, the contaminants in the SBR have migrated less than 100
feet from the point of release. Thus> the VOCs have not been
able to to migrate from the site and disperse. This accounts for
the high VOC concentrations reported from the onsite monitoring
wells.
The ultimate discharge point for the SBR is the James River
or Wilson Creek valleys.
23
-------
6C 290,000
•*VjLjVVRepublic, Mo Site
/*" 2/'' 2400
10,000-A-- «r/ :
. '<»•_.-
Mil! Street
1 250 500
ZOOO
3000 Fee:
GROUND-WATER TCE CONCENTRATIONS,
UNFRACTURED SHALLOW BEDROCK SYSTEM (SBR)
NO Not Detected Above Method Detection Limit
*. Cave Well
O SSC-_Shalio* Bedrock Monitoring \Vell
A REM-_Rccovery \\ell
The TCE Concentradcn Shovvn is th< Maximum Rs3or;sti
for All Sampling E%'ents
Concentrations in ug'L
FIGURE 7
24
-------
5.8 DBR UNIT
The DBR consists of the bedrock units from approximately
300 feet to greater than 1200 feet in depth. Figure 8
illustrates the horizontal distribution of TCE in rhe deep
bedrock. The only deep bedrock samples that showed VOC contami-
nation were limited to onsite wells and the wells near Municipal
Well Number 1.
At the site, the contaminants have migrated no further than
700 feet deep vertically, with the greater chemical concentra-
tions occurring between 150 to 300 feet in depth. At
Municipal Well Number 1, the contaminants extend vertically to a
depth of 1,000 feet, with the greater chemical concentrations
occurring between 400 to 500 feet in depth.
The.pump intake for Municipal Well Number I was set at
approximately 450 feet. Chemical data and hydrogeologic data
show that pumpage of Municipal Well Number 1 and an existing
regional upward hydraulic gradient control the vertical and
horizontal migration of the plume. Stopping the pumping of
Municipal Well Number 1 allows Municipal Well Number 1 to act as
an open conduit for contaminants to migrate to depths below 700
feet. The location of Municipal Well Number 1 approximately
represents the southern end of the plume. To date, no VOCs have
been -detected in Municipal Wells 2, 3, and 4. Although the
eastern and western boundaries of the plume have not been pin-
pointed, they are believed to extend less than 800 feet away frcn
the site, based on ground water modelling.
In the DBR, the transport of contaminants is toward the
pumping wells. Municipal Well Number 1 controlled flow from the
site until the well was shut down. Municipal Well Number 1 was
restarted; however, during the shutdown, flow from the site was
toward Municipal Well Number 2. The calculated ground water
velocity is 0.43 feet/day or 157 feet/year. The maximum probable
distance contaminants could have migrated away from the site
toward Municipal Well Number 2 since 1983 is 785 feet, approxi-
mately one-third the total distance of 2,100 feet. In the ab-
sence of onsite pumpage, it would take approximately 13 years for
the leading edge of the plume to reach Municipal Well Number 2.
However, Municipal Well Number 1 is currently pumping with, the
water discharging into the sewer, so it is controlling the flow.
of contamination from the site.
The inorganic characteristics of water in the .DBR system is
parallel to that of water from the SBR. Copper was reported
above the detection level in fourteen samples collected from
offsite DBR wells away from Main Street. The only samples that
have copper values above detection levels are from Municipal
Wells. Lead, mercury, and zinc were detected in onsite DBR wells
at concentrations of 0.007 ug/1, 0.0002 ug/1, and 0.44 ug/1,
25
-------
GROUND-WATER TCE CONCENTRATIONS,
DEEP BEDROCK SYSTEM (DBR)
NO Nuc Detected Above Method Detection Limit
"" fC'E Concentration Contour
O CW-_Municipal Well
A REM-_Recovery Well
• SSC-_Decp Bedrock Monitoring Well
FIGURE 8
The TCE Concentration Shown
is the Maximum Reported Value
for Ail Sampling Events
Conceotraoon* in ug/L
26
-------
respectively. Mercury (0.002 ug/1) and zinc (0.02 ug/1) were
detected in offsite DBR wells along Main Street. These values
are not above Federal or Missouri drinking water standards.
In onsite and offsite DBR wells, TCE again was the most
frequently detected constituent and TCE was detected at the
highest concentrations. The maximum offsite TCE concentration
was 900 ug/1 in Municipal Well Number 1. The maximum TCE concen-
tration onsite was 18,000 ug/1. Many volatile organic compounds
were detected onsite and offsite at levels above Federal or
Missouri drinking water star.aards.
5.9 UTILITIES
The utility lines are at depths below the water surface of .
the UFSB north of Brooks Street. Ground water containing VOCs
may enter the utility lines north of Brooks Street and be carried
south of Brooks Street by flow within the utility. Water in
buried utilities and the Publicly Owned Treatment Works (POTW) was
sampled and analyzed for contaminants during the RI. Table 3
presents a summary of frequency of occurrence, maximum and aver-
age concentrations, and the location of maximum concentration for
each constituent detected. Figures 9 and 10 illustrate the TCE
concentration trends for the sewer and telephone manholes,
respectively. A discussion of sewe- and telephone air contamina-
tion is contained elsewhere in the nummary of Site Risks.
The highest VOC concentrations were detected in the Republic
sewer system and the Southwestern Bell manholes along Main- Street
directly south of the site. Maximum and average concentrations
of detected chemical constituents decreased along the flow path.
No contaminants were found at detectable levels in the Republic
sewer system directly east of the site. Concentrations detected
in Southwestern Bell manholes decreased sharply away from the
site, to concentrations close to the method detection limit.
Trichloroethene was not detected in the Southwestern Bell system
north of the site or south of U.S. Highway 60.
During the RI, SSC installed two air strippers in series to
evaluate their effectiveness in removing site contaminants from
ground water, and to pretreat ground water prior to discharge to
the sewer during certain RI activities which generated large
volumes of contaminated ground water. This work was referred to
as the Pilot Study. Currently, these air strippers remain at the
site, but are not in operation. SSC had entered into an agree-
ment with the City of Republic to allow disposal of treated
ground water into the City of Republic sewer system and POTW.
Pretreatment standards for site discharge limited the flow to
200 gallons per minute and 200 ug/1 TCE. Samples were taken
every two weeks from the air stripper effluent to the sewer and
at the POTW influent and effluent. The discharge from the air
stripper into the sewer system did not exceed the pretreatment
standards. Specifically, the discharge from the air stripper
system never exceed 26 UG/L OF tee.
27
-------
TABLE 3. SUMMARY OP, CHEMICAL CONSTITUENTS DETECTED IN
WATER IN UTILITIES
CONSTITUENT
MAXIMUM/AVERAGE(1) MAXIMUM
NO. DETECTED/ CONCENTRATION CONCENTRATION
NO. ANALYZED (UG/L) LOCATION
CHLOROFORM
1 , 1-DICHLOROETHANE
1, 1-DICHLOROETHENE
1, 3-DICHLOROPROPYLENE
ETHYLBENZENE
METHYLENE CHLORIDE
TOLUENE
TRANS - 1 , 2 -DICHLOROETHENE
1,1, 1-TRICHLOROETHANE
TRICHLOROETHENE
6/50
2/50
1/50
1/26
2/50
3/50
2/50
8/49
10/50
32/50
160/
55
4.9/
4.2
2.7/
2 . 7
5.2/
5.2
3.9/
2.6
120/
49. 3
2.3/
2.3
310/
•114.8
28/
7.9
470/
147. 3
SEWER
SW BELL
SEWER
SW BELL
SEWER
SW BELL
SEWER
SEWER
SEWER
SEWER
(1) AVERAGE CONCENTRATION IS CALCULATED USING ONLY SAMPLES IN
WHICH THE CONSTITUENT IS DETECTED.
28
-------
/•Mi... g,.-
..,/
-I'
W ^ r f* cj-\n Q r n»^f
NDc^
39
139 A
|v_
\r
N9,^I£
154 153
/""
141
-30 b J
290 c(
^ T
J
il
1 . .. . i !
i
470c
262 NDt> 1
I
r-CK-r3
-------
180/10-14-87
57/5-25-83
TCE CONCENTRATIONS DETECTED IN
SOUTHWESTERN BELL MANHOLES
• Southwestern Bell Buned Line
•* • Southwestern Bell Manhole and Numbers
5.4/10-14-87 TCE Concentration/Sample Date
FIGURE 10
30
-------
The NPDES permit for the POTW does not allow the POTW
effluent to exceed 2 ug/1. Discharge from the Republic site did ;
not cause the POTW to exceed the NPDES requirements. Average TCE
levels in the influent and effluent streams for the POTW did not
change during the air stripper pilot study. One excursion did
occur but it could not be attributed to site operations.
5.10 AIR
Air sampling was conducted during the RI field activities to
document the following: the health and safety of onsite workers;
and, offsite emissions at the POTW, in the sewer and Southwestern
Bell utility manholes, in the basement of the building
adjacent to the site, and in the basement of the residential
homes near the UFSB fracture zone.
Occupational Safety and Health Association (OSHA) threshold
limit values (TLVs) were not exceeded in the normal breathing
zone of an onsite worker, i.e., approximately 4 to 6 feet from
the source. Total VOCs were above the OSHA TLV during onsite
well construction, with the monitoring instrument held close to
the source. This is not considered the breathing zone.
Offsite at the POTW, an air sample taken downgradient from
the POTW aeration pond was measured at a concentration of 45 ug/1
of 1,1,1-trichloroethane which is below the OSHA TLV; at the POTW
aeration pond, methylene chloride was found at 5000 ug/1 which is
above the OSHA TLV. Neither of these samples are considered
attributable to the site discharge for several reasons: a) the
air concentrations are far above any level which could be
achieved by air dispersion of the VOCs in the site discharge from
the POTW's brush aerator; b) methylene chloride was not detected
in ground water at concentrations which could produce the air
concentration; and, c) POTW chlorination units produce these
types of compounds.
The maximum concentrations detected in the sewer manholes
occurred at manhole No. 144 (refer to Figure 8) during the
February 1988 sampling event. The maximum concentrations were
benzene at 290 ug/1, methylene chloride at 11,000 ug/1,
tetrachloroethene at 720 ug/1, and TCE at 770 ug/1. Each of
these concentrations exceed the OSHA TLV for each contaminant.
However, a second sampling event several months later did not
detect any of these contaminants above detection limits.
The maximum concentrations detected in Southweocern Bell
manholes occurred at manhole No. 5 (refer to Figure 9) with
benzene at 29 ug/1, tetrachloroethene at 530 ug/1, and TCE at
280 ug/1. Of these concentrations, benzene is very close to the
OSHA TLV for benzene and TCE exceeds the OSHA TLV. The
Southwestern Bell concentrations were obtained when the manhole
was filled with water. Southwestern Bell standard operating
31
-------
procedure, includes pumping out the water and purging with fresh
air before and during manhole work. A second sample was taken
several months later; this sample was obtained after pumping the
water out of the manhole. Only TCE was detected and at a much
lower concentration, 3 ug/1.
In a sample taken from the basement of the building adjacent
to the site during the June 1988 sampling event, benzene was
detected at 2.0 ug/1, methylene chloride at 5,400 ug/1, tetra-
chloroethene at 1,100 ug/1, and TCE at 330 ug/1. This building
is unoccupied. Analysis of basement air samples taken from resi-
dences near the UFSB fracture zone did not reveal contamination
attributable to the site.
Currently, the site is covered with 1 to 2 feet of clean
gravel to inhibit plant growth, so fugitive dust emissions should
not be a problem.
SECTION 6.0 SUMMARY OF SITE RISKS
As part of the RI/FS process, a risk assessment was
conducted in order to assess the current and potential risks to
human health and to the environment due to the site. This risk
assessment provides a baseline risk assessment to assist in the
development of remedial alternatives. This section summarizes
the findings concerning the quantified risks. Future conditions
were evaluated such as new drinking wells installed onsite and
offsite. In addition, the risk assessment also evaluated risks
associated with certain remedial actions.considered potentially
applicable to the site: i.e., air stripping of contaminated
ground water. The risk assessment provides valuable information
used to determine the need for cleanup action(s).
6.1 IDENTIFICATION OF CONTAMINANTS OF CONCERN
As presented in the previous section, Summary of Site
Characteristics, and summarized in Appendix B, thirty-three
contaminants were identified in various media. Due to the wide
variations in occurrence, concentrations, and toxicities between
contaminants, a selection process was implemented to identify
indicator chemicals for evaluation in the risk assessment.
Indicator chemicals are selected to focus the assessment on the
chemicals that represent the most probable risk to the public and
the environment. This process resulted in the selection of seven
indicator chemicals which are presented in Table 4. Table 4 also
lists the highest concentration detected and pertinent
regulation(s) for each indicator chemical in each media, except
a i r.
32
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TABLE 4
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS OR HEALTH GUIDELINES FOR
INDICATOR CHEMICALS DETECTED AT THE REPUBLIC, MISSOURI SITE
GROUND-WATER
SURFACE WATER /POTW EFFLUENT
SOILS
Chemical
1,1-Dichloroelhane
1 , 1 -Dichloroethene
Maximum Stale of Missouri
Reported MCL^ Ground
Concentration Water
(mg/L) (VI, VII)
.890 NS .00094
1.0 .007 .007
tA\
l.2-Dichloroeihene(7««) .880 .0071 ' NS
Melhylene chloride
3.6 NS .OOOI9(7)
1.1,1-Trichloroeihane 14.0 0.2 0.2
Trkhloroeihene
Vinyl chloride
290 .005 .005
.410 .002 .002
Maximum
Reported Aquatic
(2)
Conceniralion Life
(mg/L)
ND NS
ND 11.6
ND 11.6
0.15 0
.0045 18.0
.0061 21.9
ND NS
Stale of Missouri
PiiHcciion of
Aquatic Life
(0
NS
NS
NS
NS
NS
NS
NS
Fish'
, (3)
digestion
NS
0.0018
0.0018
0
41.8
0.081
0.002
Maximum
Reported
Concentration
(mg/kg)
.450
.086
0.18
1.00
.0023
7.30
0.15
Health
Guideline
NS6
NS6
NS6
NS6
NS6
NS6
NS6
NOTE:
Unil of Concentration for all federal and stale standards is mg/L or mg/kg (ppm).
I Primary Drinking Water Standard, Maximum Conlaminanl Level (40 CFR 141 and Stale Regulations Stale of Missouri 10 CSR 60-4,100)
2 Federal Water Quality Criteria for Protection of Fresh-Water Aqualic Life (USEPA, 1986t>)
3 Federal Waier Quality Criteria (FWQC) for Fish Ingestion (USEPA, I986h)
4 Safe Water Drinking Act Maximum Conlaminant Level Goal
5 Stale of Missouri Water Quality Standards
6 Health based riski associated wild soils-are presented in Section 6.0 and Appendix B
7 Missouri Waler Quality Standard for halogenaied methanes
ND =• Not delected
NS = No standard established
-------
6.2 EXPOSURE ASSESSMENT.
Exposure assessment involves analysis of the following
factors which will affect the quantification of risks: location
of contamination, contaminant concentrations, exposure pathways,
affected populations, and exposure frequency.
As discussed previously, contamination was detected in all
media: air, surface soils, subsurface soils, ground water, and
surface water in utilities. However, the concentrations varied
significantly depending on whether the location was onsite or
offsite. As a result, risks were calculated for each media
depending on location and known concentration at that location.
Location was further defined for ground water as to whether the
ground water originated from the unconsolidated/fractured shallow-
bedrock (UFSB), the shallow bedrock (SBR), or the deep bedrock
(DBR). For example, risks were quantified for ingestion of
ground water from the DBR for. both the maximum onsite concen-
tration and for the maximum offsite concentration.
With the contamination present in all media both onsite and
offsite, many pathways for exposure to the contaminants were
evaluated based on current and future conditions. Table 5 lists
the exposure pathways analyzed.
Exposure analysis classified the population into adults,
children and infants. Exposure frequency varied depending on the
pathway of exposure. For future exposure to contaminated ground
water, exposure frequency was assumed to be seventy years for
adults, twelve years for children and two years for infants. For
exposures related to cleanup activities, the length of
remediation was assumed to last forty years resulting in exposure
frequencies of. forty years for adults, twelve years for children
and two years for infants. Exposure frequency was reduced for
worker exposure in utilities. For example, the Southwestern Bell
worker exposure was assumed to be 0.25 hours/day, 12 days/year
for 40 years.
6.3 TOXICITY ASSESSMENT
Five of the seven indicator chemicals are classified as
possible, probable or known human carcinogens with vinyl chloride
being the known human carcinogen. In Appendix C, the cancer
potency factors are presented for the indicator chemicals. These
factors are used to calculate excess cancer risks associated with
the site based on site contaminant concentrations. The EPA and
MDNR consider individual excess cancer risks in the range of 1 in
10,000 (10~4) to 1 in 10,000,000 (10~7) as protective; however,
the 1 in 1,000,000 risk level is used as the point of departure
for setting cleanup levels.
34
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RELEASE SOURCE ANALYSIS AND EXPOSURE PATHWAYS
AT THE REPUBLIC, MISSOURI SITE
CO
en
Media
Soil
Ground Water
Air
Surface Water
Oieuilcul Source/
Krlrate McchunUni
Surface soil/runoff
Surface soil/tracking
Surface soil/dosorption
onto receptor
Subsurface soil/
desorption onto receptor
Subsurface soil and
disposal releases/
leaching or desorption
Surface water/
volatilization
Ground water and
Surface soils/
volatilization
Surface soils/
fugitive dust
Ground water/
volatilisation for
Stripping lower
Surface water/effluent
from sewage lical-
mcm plain
Surface watci/cflluonl
from ail snipping lower
and gnniiKl wiici discharge
Release
l>ruluil>llllr
Low
Moderate
High
High
High
High
Low
Low
High
High
High
iNHeulla!
K.ipoiure
Pulnl
Republic,
MO, site
Republic,
MO, site
. Republic,
MO. site
Republic, MO site/
subsurface
utility linos
Republic,
MO, silo
Utilities,
sewage treat-
ment plant
effluent
Republic,
MO, site
Republic,
MO, silo
covered with
gravel
Republic,
MO, site
Discharge
stream from
sewage trcal-
ntonl planl
Stii lace water
williin uiiliiy
fuleulUI
K>pot>ure
Route
Absorption/
ingeslion
Absorjilion/
ingeslion
Absorption/
ingeslion
Absorption/
ingeslioo
Absorption/
ingeslion
Absorption
Inhalation
Inhalation
Inhalation
Absorption
AbsoniioM
Cbeuilcal
Delected •(
Kipoaurc
I'olnl
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Couipifle
K*posure
rulllHMT?
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
-------
Appendix C also lists the noncarcinogehic*-reference dose
(RfD) levels for the indicator chemicals. The RfD is a concen-
tration to which humans can be exposed to on a daily basis with-
out adverse effect. The RfDs are used to calculate the Potential
Hazard Index for each contaminant based on site contaminant
concentrations. Potential Hazard Indices greater than 1.0 would
be considered an unacceptable risk.
Cancer potency factors (CPFs) have been developed by EPA's
Carcinogenic Assessment Group for estimating excess lifetime
cancer risks associated with exposure to potentially carcinogenic
chemicals,. CPFs are multiplied by the estimated intake of a
potential carcinogen to provide an upper-bound estimate of the
excess"' lifetime cancer, risk associated with exposure at that
intake level. The term "upper bound" reflects the conservative
estimate of the risks calculated from the CPF. Use of this
approach makes underestimation of the actual cancer risk highly
unlikely. Cancer potency factors are derived from the results of
human epidemiological studies or chronic animal bioassays to
which animal-to-human extrapolation and uncertainty factors have
been applied.
Reference doses (RfDs) have been developed by EPA for indi-
cating the potential for adverse health effects from exposure to
chemicals exhibiting noncarcinogenic effects. RfDs are estimates
of lifetime daily exposure levels for humans, including sensitive
individuals. Estimated intakes of chemicals from environmental
media (e.g., the amount of a chemical ingested from contaminated
drinking water) can be compared to the RfD. RfDs are derived
from human epidemiological studies or animal studies to which
uncertainty factors have been applied (e.g., to account for the
use of animal data to predict effects on humans). These uncer-
tainty factors help ensure that the RfDs will not underestimate
the potential for adverse noncarcinogenic effects to occur.
Through the defined exposure pathways, carcinogenic and
noncarcinogenic risks exist for the exposed population due to
each contaminant. Cumulative contaminant risks are also calcu-
lated and evaluated for exposed populations by simply adding the
individual contaminant risks.
6.4 RISK CHARACTERIZATION
Quantified carcinogenic and non-carcinogenic risks are
presented in Appendix D. The results for the risk assessment
based on current conditions indicate that no unacceptable health
risks are present. This determination is based on the fact that
the UFSB and SBR aquifers are riot presently used as a drinking
water source. The deep bedrock aquifer near the site is no
longer used as a drinking water source since Municipal Well
Number 1 was removed from service. »
36
-------
However, future use of onsite and offsite ground water from
any one of the three aquifers could pose unacceptable health
risks at present contaminant levels. Dermal contact and/or
ingtstion of onsite ground water presents the greatest
carcinogenic risk. Based on drinking the most contaminated
ground water for seventy years, one additional person in ten
(1.1 X lO'1) has a chance of contracting cancer. The same expo-
sure presents the maximum, noncarcinogenic hazard index of 2,292.
Risk analysis predicts that operation of an air stripper
system will not pose an unacceptable threat to onsite workers or
offsite residents as a result of airborne contaminants. This
analysis was based on air modelling predictions for elevated
ambient air concentrations of c -caminants, on a ground water
flowrate of 150 gallons per minuce to the air stripper system,
and on contaminant influent concentrations to the system derived
from the pilot study. Also, no unacceptable health risks were
identified in association with discharging the air stripper
effluent into the sewer system.
No threatened or endangered wildlife were identified and,
thus, no critical habitats are affected by the site
contamination.
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare, or, the environment.
SECTION 7.0 DESCRIPTION OF ALTERNATIVES
Alternative j.; No Action
Alternative I is the no action alternative, required by the
NCP and SARA, and is the baseline against which the effectiveness
of other remedial alternatives are judged. Under Alternative I,
no funds are expended for monitoring, control, or remediation of
the site. The only technologies included in the no action
alternative are site perimeter fencing and new Municipal, Well 4C,
both of which have already been constructed. The existing
contaminant plumes in the three aquifers will not be remediated
except through natural attenuation. The three plumes will
increase and spread over larger areas.
Alternative II: Pump and treatment using air strippers with
treated water discharged to Publicly Owned
Treatment Works (POTW).
Major Components of the Remedial Alternative: The major
features of this alternative include extraction of contaminated
ground water from three aquifers, onsite physical/chemical
treatment using air stripping to promote volatilization of the
37
-------
contaminants from the extracted ground water,, and discharge of
the treated effluent to the Republic POTW to undergo additional
offsite treatment. The City of Republic will be asked to enact
an ordinance to prevent construction of drinking wells in or near
the contaminated plumes to prevent direct contact/ingestion of
contaminated ground water before the remediation is complete.
The transport of materials through the subsurface via ground
water was evaluated for the three hydrogeologic units defined:
the unconsolidated/fractured shallow bedrock (UFSB), the shallow
bedrock (SBR), and the deep bedrock (DBR). Transport in the UFSB
was analyzed using analytical techniques because of the limited
data base on the hydrogeologic parameters of the UFSB. Transport
in the SBR and the DBR was analyzed using a numerical ground
water and transport code to mod'el the ground water flow.
The total flow rate from all extraction wells is anticipated
to range from 150 to 175 gpm. "he extraction system for Alterna-
tive II consists of using existing and new wells for the three
aquifer system. Two extraction wells will be used for collection
of contaminated ground water from the DBR. For the SBR, three
wells will be used. For the UFSB, four new extraction wells will
be constructed.
Figure 11 diagrams the process flow for Alternative II.
Contaminated ground water from onsite and from offsite extraction
wells with TCE levels above 200 ug/1 will be piped to the onsite
air strippers for treatment. Ground water from wells with TCE
levels below 200 ug/1 will be discharged directly to the sewer.
If the TCE levels in the ground water extracted from certain
offsite wells are found to exceed 200 ug/1, the ground water will
be pumped to-a wellhead treatment system consisting of either a
carbon adsorption system or air stripper units.
The air strippers were used during the RI/FS to provide
pretreatment of fluids generated from onsite RI activities such
as well construction and aquifer testing, and to initiate a pilot
program to test the feasibility of proposed remedial actions.
The average removal efficiency fcr TCE was 98 percent for each
tower resulting in a total removal efficiency o-r over 99 percent.
Air stripper modifications may include Best Available
Control Technology (BACT) for air emissions, depending on future
federal and state air emissions regulations.
The stripper tower air emission rates will be evaluated on a
frequent basis to verify that stripper tower emissions continue
to pose no unacceptable public health risks. The need for an
ambient air monitoring program will be evaluated during remedial
design. The major ARARs are National Primary and Secondary
Ambient Air Quality Standards (40 CFR Part 50) and state air
quality De Minimis Emission Levels [10 CSR 6.060 (7)(A)].
38
-------
DEEP BEDOOCK
EITKACTION WELLS
CO
UD
CD
cr
PO
HEM- I
SH*LLO« BIOHOCX
CITHACIION WILLS
SSC - 5A
SHALLOW
UNCOHSOLIDATED
EXTRACTION WELLS
SSC-50
SSC-51
V£NT
BlOCIDt FEED
EQUIPMENT
L3
3SC-5Z
FLOW
EQUALIZATION
TANK
WtiLHEAD 1HIAIUIN1
'Of) TO NCAHtST SCWCK
UAMHOiE
5L»tR PIPSLUt
TO BtPUBLIC POTW
ALTERNATIVE JI
PROCESS FLOW DIAGRAM
-------
The state has two ground water classifications in its water
quality standards, VI and VII. Category VI limits apply if the
aquifer recharge has an effect on surface water designated for
aquatic life protection. The UFSB and the SBR systems are in
this category. Category VII limits apply if aquifer recharge has
a negligible effect on surface water designated for aquatic life
protection. The DBR is in this category. Additionally, the
state has a ground water protection strategy. The state's ground
water protection goal is to maintain the quality and quantity of
the state's ground water at the. highest level practicable, as
necessary to support present and future beneficial uses. The . .
state of Missouri classifies all ground water as Class II, cur-.
rent and potential sources of drinking water and water having
other, beneficial uses. Class I and III are not recognized in the
state.
When the remediation is complete, the ground water in all
three aquifers will be restored for future use, by reducing the
site contaminants in ground water to their respective ARAR
levels. The area of attainment is the entire plume, since the
soil source has been removed. Cleanup levels will be achieved in
the entire plume. The major ARARs are federal National Primary
Drinking Water Standards (40 CFR Part 141), state Maximum
Inorganic Chemical Contaminant Levels (10 CSR 60-4.030), state
Maximum Volatile Organic Chemical Contaminant Levels
(10 CSR 60-4.100), and state water quality standards in ground
water (10 CSR 20-7.031). '
Management of Residuals. Treated effluent from the air
strippers will be discharged to the Republic sewer system. The .
adequacy of the sewers to convey the treated effluent for the
duration of the remedial action is uncertain. Moving the
location where the. effluent enters the sewers may alleviate some
of.this uncertainty. New sewers with larger capacities exist
within 2,600 feet of the site and will require either a highway
or a railway crossing. The discharge point to the sewer will be
evaluated during remedial design.
Sewers have adequate capacity to handle the treated effluer.t
flow, except possibly under the high infiltration/inflow condi-
tions that can occur during rainstorms. Flow depth monitoring
equipment will be installed in discharge sewer manholes so that
extraction will cease during periods of high sewer flow.
From the site, the sewer will carry the treated effluent to
the Publicly Owned Treatment Works (POTW), where additional
aeration and mixing occurs. The POTW sludge amount will not
increase due to the low biological oxygen demand (BOD)/solids
loading and metals concentrations of the SSC site discharge. The
POTW effluent is discharged to Dry Branch, the receiving stream.
The POTW operates under a state NPDES permit which includes a TCE
monthly average discharge limit of 2 ug/1. The plant should be
40
-------
able to accept the 150 to 175 gpm without adverse effects since
the flow will be virtually free of organic/solids loading.
However, during the predicted life ot the remediation, if the
projected growth of the city becomes ^ reality, the City of
Republic will need to expand the plant's aeration capacity to
meet the increasing organic/solids loading.
The major ARARs for the discharge component are the National
Pretreatment Standards, 40 CFR Part 403, and the pretreatment
standards of 200 ug/1 TCE and 200 gallons per minute established
by the City of Republic and the already existing NPDES permit for
the POTW discharge to Dry Branch. The state water quality
standards for aquatic life protection (10 CSR 20-7.031) are used
to establish the discharge limits.
The estimated capital cost of the remedy is $274,800, with
annual O&M costs estimated to be $445,300. Assuming a 10 percent
discount rate, the present worth is $4,629,400.
Alternative III: Pump and treatment using metals removal, air
strippers, and carbon adsorption with treated
water discharged to Shuyler Creek.
Major Components of the Remedial Alternative. The major
features of this alternative includes extraction of contaminated
ground water from three aquifers; onsite physical/chemical
treatment using metals removal, existing air strippers, and
carbon adsorption; and offsite discharge of the treated effluent
through a pipeline to Shuyler Creek located approximately two
miles south of the site.
The ground water extraction system will be identical to the
extraction system described for Alternative II. The type and
volume of waste treated, ground water classifications, cleanup
levels, area of attainment, restoration timeframe, and major
ARARs are the same as Alternative II.
Management of Residuals. Figure 12 diagrams the process
flow for Alternative III. The treatment unit processes will
consist of metals removal, air stripping, and carbon adsorption.
The contaminated ground water will first pass through the metals
removal facilities which will consist of flocculation/clarifi-
cation facilities with a capacity of 150 gpm. Chemicals will be '
added to the ground water to form metal hydroxides which settle
out in a clarifier. The clarifier will remove the flocculated
metals and solids from the water. Excess metals sludge will be
pumped to a sludge holding tank for storage, a filter press will
dewater it, and the sludge will be disposed of in a RCRA approved
hazardous waste landfill. After the metals are removed, the
contaminated water is pumped to the air strippers for further
treatment. The air strippers are sized to treat 150 gpm. The
treated effluent from the air stripper is then pumped to the
41
-------
IX)
OEtP BEDHOO
EXTRACTION WELLS
SHALLOW BEOKOCK
EXTRACTION wtLLS
n
SHALLOW
UNCONBOLIDATED
EXTRACTION WELLS
TO NE&MEST
SEWER MANHOLE
FEED
0
o
RAPID MIX
TANK
SOLIDS DISPOSAL
SUPERNATANT
SLOW MIX TANK
FLOW
EQUALIZATION
TANK
WELLHEAD TREATMENT
»• OR TO NEAREST SEWER
MANHOLE
SLUDGE
PUMP
FEED PUMP
.LOWER W
i—1—1 —J .—--i-
COMPRESSED
AIR HEADER
AIR S1RIPPER THANStEK
PUMP
AIR STRIPPER 1HANSFER
PUMP
SPENT
CARUON
AFTERFILTERS
PIPELINE TO
SHUTLER
CREEK
PROCESS WATER
PUMP
PROCESS
WATER
HEAOEf
DI1CHARM
PUMP
ALTERNATIVE HC
PROCESS FLOW OIAGHA
-------
carbon adsorption facilities as a polishing step. The carbon
adsorption facility has two contactors which hold granular
activated carbon (GAG) and has a capacity of 150 gpm. The
organic contaminants in the water adsorb or adhere to the carbon
particles. When the carbon is spent, it is removed and replaced
by a vendor specializing in this service. The major ARARs for
the air emissions are National Primary and Secondary Ambient Ai-
.Quality Standards (40 CFR Part. 50) and state air quality
De Minimis Emission Levels [10 CSR 6.060 (7) (A)]. The major
.ARARs applicable to the disposal of residuals are the Solid Waste
Disposal Act (SWDA), 42 USC Section 6901-6987.
The final treated effluent will be collected in an onsite
tank and pumped through a discharge pipeline to Shuyler Creek.
The pipeline would be constructed using standard open-cut
trenching techniques, except where it passes under Highway 60.
The exact route of the pipeline from the site to the creek will
.be determined during remedial design. The major ARAR applicable
to this discharge will be an NPDES permit applied at Shuyler
Creek. The state water quality standards for aquatic life pro-
tection (10 CSR 20-7.031) will be used to establish the discharge
parameters and limits. Metals removal and carbon adsorption are
needed for this alternative because it is anticipated that the
direct discharge to Shuyler Creek will need to meet stringent
discharge limits. Shuyler Creek is a low flow stream which
provides little dilution, so the permit limits will be at or
slightly higher than the Missouri water quality standards for
aquatic life protection.
The estimated capital cost of the remedy is $2,471,100, with
annual O&M costs estimated to be $977,200. Assuming a 10 percent
discount rate, the present worth is $12,027,200. The estimated
time to implement this remedy and to meet the cleanup goals is
the same as for Alternative II. The health risks goals at the
completion of the remedial action are also the same as
Alternative II.
ALTERNATIVE IV: Pump and treatment using air strippers and
carbon adsorption with treated effluent
discharged to the deep bedrock aquifer as
enhanced ground water contaminant recovery.
Major Components of the Remedial Alternative: The major
features of this alternative includes extracting contaminated
ground water from each of the three different aquifer systems,
onsite physical/chemical treatment of the water using the
existing onsite air strippers and new carbon adsorption
facilities, and discharging the treated effluent through
pipelines to three reinjection wells which are open to the deep
bedrock as part of an enhanced ground water contaminant recovery
system.
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The ground water extraction system for- Alternative' IV is
identical to the extraction system for Alternative II. The type
and volume of waste treated, ground water classifications,
cleanup levels, area of attainment, and major ARARs are the same
as Alternative II. The restoration timeframe for the UFSB and
the SBR is the same as for Alternative II. The time required to
remediate the deep bedrock aquifer under Alternative IV is antic-
ipated to be 10 to 30 years shorter.
Management of Residuals. Figure 13 diagrams the process flow
for Alternative IV. The treatment system will consist of air
stripping and carbon adsorption. The existing air strippers, will
be-identical to those proposed for Alternative II, and the new
carbon adsorption facilities will be identical to those described
in Alternative III. The major ARARs for the air emissions are
National Primary and Secondary Ambient Air Quality Standards
(40 CFR Part 50) and state air quality De Minimis Emission Levels
[10 CSR 6.060 (7) (A)]. The major ARARs applicable to the carbon
regeneration are the Solid Waste Disposal Act (SWDA), 42 USC
Section 6901-6987.
Treated effluent will be collected in an onsite tank and
pumped through discharge pipelines to three reinjection wells as
part of an enhanced ground water contaminant recovery system.
The reinjection wells will be cased down through the shallow
unconsolidated system, shallow bedrock aquifer, and Northview
shale 'layer. The wells will be open to the deep bedrock aquifer.
The construction details and the exact locations of the three
wells and their associated pipelines will be determined during
remedial design. The major ARARS are Underground Injection
Control (UIC). Regulations, 40 CFR Parts 144 - 147, and State UIC
regulations, 10 CSR 20-6.090, Class III Mineral Resources Injec-
tion Production Well.
The estimated capital cost of the remedy is $1,323,600, with
annual O&M costs estimated to be $665,100. Assuming a 10 percent
discount rate, the present worth is $7,827,600. The estimated
time to implement this remedy and to meet the cleanup goals is
the same as for Alternative IT, with the exception of the deep
bedrock aquifer. This will be shorter. The health risks goals
at the completion of the remedial action are also the same as for
Alternative II.
SECTION 8.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
Alternatives were developed to respond to the ground water
contamination in each of the three aquifers. The alternatives
described in the preceding section were evaluated using criteria
related to factors mandated in Section 121 of CERCLA/SARA. The
nine criteria are as follows: •
44
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DEEP BEDROCK
EXTRACTION WELLS
70
m
SHALLOW BEDROCK
t X TRACTION WCLL5
I ssc-sc
SHALLOW
UNCONSOLIDATED
EXTRACTION WELLS
S5C-21
SSC-31
SSC-5Z
10 NEAREST
SEWER MANHOLE
1
m
PREFILTER3
Flow FEED PUMP
EQUALIZATION
TANK
R^
BIOCIDE FEED
EQUIPMENT
-fi
1
•^
WELLHEAD TREATMENT
OR TO NEAREST SEWER
MANHOLE
AIR STRIPPER TRANSFER AIR STRIPPER TRANSFER
PUMP PUMP .
DISCHARGE PUMPS
XEINJECTION WELLS
ALTERNATIVE JZ
PROCESS FLOW DIAGRAM
-------
Threshold Criteria
Overall Protection of Human Health and Environment
addresses whether or not a remedy provides adequate
protection and describes how risks through each
pathway are eliminated, reduced or controlled
through treatment, engineering controls, or
institutional controls;
Compliance with Applicable or Relevant and Appro-
priate Requirements (ARAKs) addresses whether or not
a remedy will meet all of. the applicable or relevant
and appropriate requirements of other Federal and
State environmental statutes and/or provide grounds
for invoking, a waiver;
Primary Balancing Criteria
Long-Term Effectiveness and Permanence refers to the
magnitude of residual risk and the ability of a remedy to
maintain reliable protection of human health and the
environment over time once cleanup goals have been met;
Short-Term Effectiveness refers to the speed with which
the remedy achieves protection, as well as the remedy's
potential to create adverse impacts on human health and
the environment that may result during the construction
and implementation period;
Reduction of Toxicity, Mobility, or Volume through
Treatment is the anticipated performance of the treatment
technologies that may be'employed in a remedy;
Implementability is the technical and administrative
feasibility of a remedy, including the availability of
materials and services needed to implement the chosen
solution;
Cost includes capital, and operation and maintenance -
costs;
Modifying Criteria
State Acceptance indicates whether, based on its
review of the RI/FS and Proposed Plan, the State
concurs, opposes, or declines comment on the pre-
ferred alternative;
46
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Community Acceptance which is assessed in the
Responsiveness Summary which is attached to this
Record of Decision (ROD), and which reviews the
public comments received during the public
comment period.
Each alternative was evaluated against the specific criteria
described above to assess the relative performance of each
alternative. This comparative analysis is summarized below:
Overall' Protection of Human Health and the Environment:
Alternative I, the No Action Alternative, will not be pro-
tective of1 human health and the environment. The contaminant
plume will migrate toward the currently uncontaminated municipal
wells and present future health risks to ground water users. The
existing contamination in the ground water already exceeds state
and federal drinking water standards and state water quality
standards for ground water.
Alternatives II, III, and IV will all be equally protective
of human health and the environment by extracting and treating
the contaminated ground water. To prevent unacceptable short-
term impacts, city ordinances will prevent construction of new
wells within or near the contaminant plumes to prevent ingestion
of the contaminated water before the remediation is complete.
The contaminants will be permanently removed from the ground
water. All three alternatives will utilize treatment systems
which include, as a minimum, an air stripping process to remove
the contaminants of concern. Air modelling has been conducted
which shows that the stripper tower emissions will not pose an
unacceptable public health risk, so there are no cross-media
impacts associated with the remedies. At the completion of the
remediation, the site contaminants in .all three aquifers will be
reduced to their /espective ARARs, thereby bringing the exposure
levels within an acceptable risk range.
Compliance with ARARs;
Alternative I will not meet ARARs since the contaminant
concentrations will not be reduced and no action will .be taken.
Alternatives II and III will meet their respective Applicable or
Relevant and Appropriate Requirements (ARARs) of federal and
state environmental laws; however, Alternative IV may not comply
with a state statute. Alternatives II, III, and IV will reduce
the ground water contamination to meet state and federal stand-
ards for drinking water supplies, state water quality standards
for ground water, and existing state and federal air regulations.
However, new air toxics regulations may require modification to
the air. stripping system.
47
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Additionally, Alternative II will comply with pretreatment
standards before discharging the treated effluent to the sewer
system. The Publicly Owned Treatment Works • (POTW), or the sewage
treatment plant, has an existing National Pollutant Discharge
Elimination System (NPDES) permit applied at Dry Branch.
Alternative III will treat the extracted ground water to
meet National Pollutant Discharge Elimination System (NPDES)
discharge limits to Shuyler Creek. Metals removal is needed for
this alternative in anticipation of meeting stringent discharge
limits established for the direct discharge to the low-flow
stream.
Alternative IV may not comply with a state law which
prohibits the disposal of wastewater via reinjection wells
(577.155.1 RSMo) . The applicant .for the reinjection permit will
need to demonstrate to the state how the alternative does not
constitute disposal and how it will enhance ground water
contaminant recovery.
No waiver from the ARARs is required to implement any of the
active cleanup options.
Long-term Effectiveness and Permanence:
For Alternative I, the No Action Alternative, the plumes
will continue to migrate and eventually, in the deep bedrock
aquifer, contaminate Republic's water, supply. No controls or
monitoring of the aquifer will be provided.
Alternatives II, III, and IV will involve long term pump and
treat remedies requiring approximately forty years. A five year
review will be required because the remedies will result in
hazardous substances remaining onsite above health-based levels
during the remediation. At the completion of the remediation,
the ground water in all three aquifers will be restored for
future unrestricted use by reducing the site contaminants to
their respective ARAR levels.
Alternatives II,' III, and IV use air strippers in their
ground water treatment systems. Countercurrent packed tower
(CCPT) air stripping is a well documented and established
technology for VOC removal. As an example, CCPT air strippers
can remove greater than 99 percent of TCE in solutions. The
actual performance of the two air strippers operating in series
was evaluated during a period of aquifer testing by the PRP at
the site in 1988. The average TCE removal using both towers was
99.89 percent. VOC removal efficiency is not influenced by
changes in concentration and is independent of air temperature.
Operational problems which can occur' are biological growth within
the packing material, corrosion problems caused by the introduc-
tion of oxygen, noise from air blowers, and freezing within the
48
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stripper media during winter months. Possible solutions include
biological growth inhibitors, corrosion resistant materials,
silencers or mufflers, and housing the entire stripper unit in a
heated enclosure.
Alternative II will use the POTW as a secondary treatment
system for the air strippers. The POTW is expected to be capable
of handling the discharge from the site without adverse effects
since the flow will be virtually free of organic/solids loading.
However, if the projected growth of the city becomes a reality,
the City of Republic will need to expand the plant's aeration
capacity to meet the increasing organic/solids loading during the
predicted life of the remediation.
The treatment system for Alternative III consists of metals
removal and carbon adsorption facilities in addition to air
strippers. The discharge to the creek will reguire freguent
monitoring to ensure that the anticipated stringent NPDES limits
are met. Additional operations management to plan and obtain
chemicals for the metals removal facilities and replacement
carbon will also be required. Residuals will be generated by the
carbon adsorption facilities in the form of spent carbon and by
the metals removal facilities in the form of .metals sludge. The
spent carbon will be regenerated and the metals sludge will be
properly disposed of at a RCRA approved disposal facility.
Alternative IV will use carbon adsorption facilities as
secondary treatment prior to reinjection in deep bedrock aguifer
wells as part of an enhanced ground water contaminant recovery
system. Carbon adsorption is a conventional treatment process
that will remove a broad spectrum of organic compounds from
dilute aqueous solutions. Granular activated carbon (GAC) fil-
tration generally will remove 99 percent or more of VOCs. There
are several disadvantages to GAC use, the most significant being
the short contaminant breakthrough times which result in frequent
carbon replacement. Spent carbon, contaminated with VOCs, must
be regenerated or disposed of in a RCRA facility. Influent
contaminants and concentrations can significantly affect the GAC
treatment performance. When the GAC adsorbent capacity nears
exhaustion, previously adsorbed material may be desorbed into the
treated water if a reduction in the influent concentration
occurs. The performance of GAC filters is more consistent if
influent quality is constant. Flow equalization and blending
facilities may be necessary to ensure optimum treatment.
Clogging of GAC surfaces and reduction of treatment efficiency
can occur if the influent contains suspended solids or oxidized
.iron. Chlorination may be required to control bacterial growth
which can occur in GAC filters.
Alternative II is the most reliable. It will require
periodic monitoring of the SSC discharge and the POTW to ensure
that pretreatment and NPDES standards are not being exceeded. It
49
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does7require the least amount'of monitoring'in' comparison to the
other alternatives. The POTW sludge amount will not" increase due
to the low biological oxygen demand (BOD)/solids loading of the
site discharge, so this alternative will produce no residuals.
Reduction of Toxicity. Mobility, and Volume;
Alternative I will not reduce the toxicity or mobility of
the contaminants, and the volume of contaminated ground water
will, increase as the plume migrates.
All three, of the. remaining alternatives equally reduce the
mobility and volume of the contaminants. Alternatives II, III,
and IV will irreversibly reduce contaminant levels in all three
aquifers to levels which satisfy ARARs. Air stripping will
remove the volatile organics from the ground water and volatilize
them. Over ninety-nine (99%) percent of the VOCs are removed by
the air'stripping process. Mathematical air modelling has shown
that the air emissions from the air strippers will pose no long
term unacceptable health risks to area residents. Alternatives
II uses the POTW as a finishing step to further reduce TCE levels
to below 2 ppb, the limit established for TCE in the NPDES permit
for the POTW discharge at Dry Branch. Alternative III will
produce a residual metals sludge which will be disposed of in a
RCRA disposal facility, thereby reducing its mobility but not its
toxicity. Regeneration of the spent carbon residual from the
carbon adsorption facilities will destroy the VOCs. Alternative
IV uses carbon adsorption as the finishing step to reduce the TCE
levels to meet the Underground Injection Control (UIC) permit
requirements. GAC filtration will remove 99 percent or more of
TCE from dilute aqueous solutions. Any volatiles absorbed by the
'carbon will be destroyed during carbon regeneration.
Future use of onsite and offsite ground water from any one
of the three aquifers could pose unacceptable health risks at
present contaminant levels. Dermal contact/ingestion of onsite
ground water poses the greatest principal threat. The treatment
processes employed by Alternatives II, III, and IV will reduce
the inherent hazards posed by the principal threats at the site.
Short-Term Effectiveness:
Alternative I will not increase risks to the community,
environment, or workers since no construction activities are
planned. Potential environmental impacts from the existing
conditions will not be changed.
Alternatives II, III, and IV provide adequate and
approximately equal protection to the community and workers
during the remedial action. City ordinances placing limits on
new well construction in or near the plume will be implemented
for all three alternatives to prevent ingestion of the
50
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contaminated ground water during the remediation. Alternatives
II, III and IV will require construction of onsite and offsite
extraction wells. Any release of volatiles during well construc-
tion will rapidly disperse and not pose a public health risk.
The site perimeter fence will minimize risks to the community
posed by onsite construction of the new treatment facilities
required for Alternatives III and IV. The gravel already
covering the site will minimize dust emissions. ' Additionally,
Alternative III will involve construction of the approximately
two-mile discharge pipeline from the site to Shuyler Creek. Con-
struction of the pipeline will pose normal risks associated with
construction of buried pipelines. Alternative IV will include
construction of the new reinjection wells. Short-term effects
associated with the construction of the new reinjection wells
will be the same as those associated with the drilling of the
offsite extraction wells.
Drawdown of- the aquifer, which is normal during ground water
extraction, vill not create any significant environmental impacts
under Alternatives II, III and IV. The increased flow in Shuyler
Creek from Alternative III will not create any unacceptable
environmental impacts. For Alternative IV, reinjection into the
deep bedrock aquifer may locally change the ground water gradient
and flow direction but will not create any significant
environmental impacts.
Implementability;
Alternative I does not use any controls or technologies
which will require coordination with other agencies.
All three alternatives are approximately equal in terms of
technical feasibility, administrative feasibility, and
availability of services and materials. Alternative II is
slightly more feasible technically and administratively.
Alternatives II, III, and IV should not be difficult to
implement. The services and required materials are readily
available. The treatment technologies used in Alternatives II,
III, and IV will meet the statutory preference for treatment as
the principal element of the remedial action. All three alterna-
tives will require coordination with MDNR to comply with any new
air toxics regulations.
Alternative II will require the least coordination with
MDNR, EPA, and the City of Republic since minimal construction is
planned. Alternatives III and IV will require more construction
than Alternative II. Alternative III will require coordination
with the state and local highway departments to cross underneath
Highway 60 with the discharge pipeline. Obtaining a NPD.ES permit
will also be required to discharge to Shuyler Creek. Alternative
IV wi41 require coordination with MDNR to obtain a reinjection
permit, and this may violate a state statute which prohibits the
51
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disposal ofwastewater via reinjaction wells. The applicant for
the reinjection permit will need to coordinate closely with the
MDNR to ensure that the statute is not violated and to
demonstrate how the reinjection will enhance ground water
contaminant recovery. Reinjection wells have not been used
extensively in the State of Missouri as a means of plume
management. • - .
Costs;
Alternative I will have zero cost.
Alternative II will have an estimated capital cost of
$274,800, an estimated annual operation and maintenance (O&M)
-ost of $445,300, and an estimated implementation time frame of
40 years. Assuming a 10 percent discount rate, the present worth
is $4,629,400.
Alternative III will have an estimated capital cost of
$2,471,100, an estimated annual O&M cost of $977,200, and an
implementation time frame of 40 years. Assuming a 10 percent
discount rate, the present worth is $12,027,200.
Alternative IV will have an estimated capital cost of
$1,323,600, an estimated annual O&M cost of $665,100, and an
estimated implementation time frame of 40 years. Assuming a
10 percent discount rate, the present worth is $7,827,600.
Alternative II is the least costly. Alternative III is the
most costly.
State Acceptance:
Representing the State of Missouri, the Missouri Department
of Natural Resources' selected Alternative II in the proposed
plan as its preferred alternative. The state is the lead agency
for this site. However, under the Superfund law, it is EPA who
must make the decision, in consultation with the state, on what
the final remedy will be. MDNR has concurred with EPA's final
remedy selection.
Community Acceptance;
The reservations, concerns, and supporting or opposing
comments of the community on the RI/FS, the Proposed Plan, and
other information in the administrative record were made known to
the State of Missouri and EPA during the thirty day comment
period and the public meeting with the community on August 24,
1989. The public's comments will be addressed in the responsive-
ness summary, which is a component of this .Record of Decision for
the site. .
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SECTION 9.0 THE SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the
detailed analysis of the alternatives, and public comments, both
EPA and the State of Missouri have determined that Alternative
II: Ground Water Pump and Treatment using Air Strippers with
Treated Water discharged to Publicly Owned Treatment Works (POTW)
is the most appropriate remedy for the Solid State Circuits Site
in Republic, Missouri.
The volume of volatile organic compound (VOC) contaminated
ground water that will be treated by air stripping differs in
each aquifer. The estimated volume of water contained within the
plume north of Highway 60 is 15 million gallons in the unconsoli'-
dated residual soils and fractured shallow bedrock (UFSB). The
estimated volume of waters in the shallow bedrock (SBR) contain-
ing VOCs is 790,000 gallons. For the deep bedrock (DBR), the
estimated volume of VOCs is 42 million gallons. The volume of
water that must be treated to remediate a given volume of water
is estimated to be about ten times the contaminated volume.
Approximately 99 percent of the VOCs will be removed by air
stripping. The additional one percent will be discharged to the
POTW to undergo secondary treatment to further reduce the VOC
concentration. The air stripping process will transfer the VOCs
from the ground water to the air stream for release to the atmos-
phere. Air modelling of the airborne concentrations predicted
that the potential cancer risk and the hazard index ratios are
acceptable.
The extraction system for Alternative II consists of using
existing and new wells for the three aquifer system. Two
extraction wells, onsite REM-1 and offsite CW-1, will be used for
collection of contaminated ground water from the deep bedrock
system. Several other deep bedrock wells are available for use
as extraction wells; however, REM-1 and CW-1 will be the main
wells used. For the shallow bedrock aquifer, onsite wells SSC-6C
and REM-2 and offsite well SSC-3A will be used for extraction of
the contaminant plume. For the shallow unconsolidated system,
new extraction wells will be constructed. These new wells will
be designated SSC-29 through SSC-32. SSC-29 will be located
onsite, SSC-30 will be near CW-1, and the remaining two will be
located to intercept and capture the entire shallow unconsoli-
dated system contaminant plume. The exact well design and loca-
tion will be determined during remedial design. Although not
selected for a detailed analysis, the. ground water collection
scenario which consists of extraction wells and a subsurface
interceptor trench and drain may be retained for consideration
during remedial design/remedial action, or after additional site
characterization has been completed. A change wil_ be made in
the contaminant recovery method for the shallow unconsolidated
system only if the four extraction wells are not controlling ani
recovering the contaminants.
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The total flow rate from all extraction wells is anticipated
to range from 150 to 175 gpm. The UFSB can be pumped at rates
ranging from 6 to 15 gpm. The SBR will not be capable of
supplying any more than 1 to 5 gallons per minute per well loca-
tion. In the deep bedrock aquifer, analyses indicate that a
remedial pumping rate of 50 gpm will control ground water flow
beneath the site under current municipal pumpage conditions. The
numerical modeling also indicates that remedial pumpage of 50 gpm
will control, ground water flow even with the increased demands
projected for the year 2005. The remedial pumping rate may need
to be increased as municipal pumpage rates exceed the simulated
2005 pumpage' of 150% of 198B pumpage. The actual pumpage rate
increase required will be based on water level monitoring of the
deep bedrock aquifer.
Previously, Figure 11 diagrammed the process flow for
Alternative II. The treatment system for Alternative II will
consist of using the two existing .air strippers located onsite.
Contaminated ground water from onsite and from offsite extraction
wells with TCE levels above 200 ug/1 will be piped to the onsite
air strippers for treatment. Ground water from wells with TCE
levels below 200 ug/1, which includes CW-1 and may include SSC-31
and SSC-32, will be discharged directly to the sewer. If the TCE
levels in the ground water extracted from these wells are found
to exceed 200 ug/1, the ground water from CW-1 will be pumped to
the onsite treatment system and ground water from SSC-31 and
SSC-32 will be pumped to a wellhead treatment system consisting
of either a carbon adsorption system or air stripper units.
Periodic monitoring will.be performed to verify that TCE levels
are acceptable. The air strippers will remove the volatile
organic contaminants from the ground water by forcing air coun-
tercurrently through the waste stream, and the volatile,
dissolved gases will be transferred to the air stream for release
to the atmosphere. The maximum rated flow capacity of each air
stripper is 150 gallons per minute.
The air strippers were used during the RI/FS to provide
pretreatment of fluids generated from onsite RI activities such
as well construction and aquifer testing, and to initiate a pilot
program to test the feasibility of proposed remedial actions.
Ground water TCE concentrations pumped to the stripper system
ranged from 2,100 ug/1 to 4,900 ug/1. The maximum TCE concen-
tration in the discharge from the air stripper system was 26.0
ug/1. The minimum TCE removal efficiency was 99.8 percent during
the pilot study. Air stripper modifications may include a Best
Available Control Technology for emissions, dependent on future
federal and state air emissions regulations.
Treated effluent from the air strippers will be discharged
to a manhole adjacent to the site. Sewer pipelines adjacent to
the site consist of eight inch diameter vitrified clay pipe. The
adequacy of the sewers to convey the treated.effluent for the
54
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duration of the remedial action is uncertain. The sewer system
has the capacity to accept the estimated site discharge flow of
150 gallons per minute. However, during rainfall events, the
city has experienced sewer backup problems. The Main Street
sewer is the smallest line in the system and the most likely to
experience capacity problems during rainfalls. The obvious site
discharge point to the sewer would be into the Main Street sewer.
Also, the Main Street sewer is an old, vitrified clay pipe line
with many cracks and faults. Moving the location where the
effluent enters the sewers may alleviate some of this
uncertainty. New sewers with larger capacities exist within
2,600 feet of the site and will require either a highway or a
railway crossing. The discharge point to the sewer will be
evaluated during remedial design. Sewers have adequate capacity
to handle the treated effluent flow, except possibly under the
high infiltration/inflow conditions that can occur during rain-
storms. Flow depth monitoring equipment will be installed in
discharge sewer manholes so that extraction will cease during
periods of high sewer flow.
From the site, the sewer will carry the treated effluent to
the Publicly Owned Treatment Works (POTW), where additional
aeration and mixing occurs. The POTW effluent is discharged to
Dry Branch, the receiving stream. The POTW operates under a
state NPDES permit which stipulates a TCE monthly average dis-
charge limit of 2 ug/1. Analysis of the POTW, into which the
sewer system discharges, indicates that discharge from the site
of up to 200 gallons per minute and 200 ug/1 TCE will not.
adversely effect the operation of the POTW. Also, metals concen-
trations detected in ground water are well below any pretreatment
standards and, thus, metals removal of the ground water is not
required before discharge to the POTW. Both of these observa-
tions are supported by the fact that the POTW experienced no
problems while accepting site discharge during the pilot study.
The Republic POTW has a design average flow of 926,880
gallons per day (gpd) and a peak flow of 7.34 million gallons per
day (mgd). More important design parameters are the design
organic and solid loading factors, since they limit the plant's
capacity and capability to treat and therefore meet NPDES
requirements. Flows to the plant can be considerably higher than
the design flow and still provide the required treatment so long
as the organic and solid loadings are not exceeded. The site
discharge is ground water and does not add to the organic and
solid loads on the POTW.
Computer modelling of the Republic POTW was.conducted for an
influent flow consisting of the designed flow of 0.8 mgd at the
design organic and solid loadings plus 0.66 mgd of water free of
organic and solid loads. The results indicate that the plant
could handle this total flow of 1.46 mgd without deterioration of
its treatment capabilities merely by modifying its operational
55
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regime. Adding the site discharge at 150 gallons per minute
(0.216 mgd) to the design flow produces a total flow of
1.114 mgd which is well within the modelled capacity of 1.4.6 mgd.
To address air emission concerns related to the air stripper
system, computer modelling was conducted to determine elevated
VOC concentrations in the ambient air. The Industrial Source
Complex Long Term (ISCLT) model was -used.' The ISCLT is an EPA
air quality dispersion model which uses historic meteorological
data for the area ~f interest and site specific chemical data to
estimate;potential contaminant concentrations at predicted
locations of maximum effect.
The meteorological data from Springfield, Missouri and
emission rates calculated from the pilot study were used in the
ISCLT modelling effort. The model solves for the distribution of
contaminants in the air at ground level. Ten locations are
identified by the model as those points predicted to have the
highest concentration. Figure 14 shows the TCE air concentration
based on a ground water pumping rate of 150 gallons per minute
and at the maximum predicted emission rate from the air stripper
towers. The predicted, maximum TCE location and concentration is
due north of the site at 1.57 micrograms per cubic meter.
The estimated capital cost of the remedy is $274,800, with
annual O&M costs estimated to be $445,300. Assuming a 10 percent
discount rate, the present worth is $4,629,400. Tables 6, 7 and
8 present in detail the estimated costs of the remedial action.
Some changes may be made to the remedy as a result of the
remedial design and construction processes, thereby affecting the
estimated costs. Such changes, in general, reflect modifications
resulting from the engineering design process.
Remediation Goals .
The purpose of this response action is to prevent potential
exposure to contaminated ground water, protect uncontaminated
ground water for future use by preventing further migration of
the contaminated ground water plumes, and restore contaminated
ground water for future use by reducing the site contaminants to
their respective ARAR levels. Existing conditions at the site
have been determined to pose an excess lifetime cancer risk as
high as one person in ten and a lifetime non-carcinogenic risk as
high as 2,292 from future direct contact/ingestion of onsite
ground water. This risk relates to the 70C concentrations
(primarily TCE) in ground water which averages 40,000 ug/1 onsite
in the UFSB, 30,000 ug/1 onsite in the S.BR, and 3,000 ug/1 in the
DBR. .This remedy will address all ground waters with contami-
nants above their respective ARAR levels. As an example, TCE in
excess of 5 ug/1 will be remediated. At the completion of the
remediation, the level of site contamination remaining in ground
56
-------
200m
-200m -150
PREDICTED CONCENTRATION CONTOURS FOR A TCE
AIR EMISSION RATE OF 34.76 MILLIGRAMS PER SECOND
AT A FLOW RATE OF 150 GALLONS PER MINUTE
.{odeI Run I
.Suck H
-------
REPUBLIC, MISSOURI SITE
FEASIBILITY STUDY
FINAL GROUNDWATER ALTERNATIVES
PRESENT WORTH ANALYSIS
ALTERNATIVE DURATION
(YRS)
CAPITAL ANNUAL PRESENT WORTH
COST COST 5%
Discount
Rate
8%
Discount
Rate
10%
Discount
Rate
III
IV
40 $274,800 $445,300 $7.915,700 $5,584,800 $4,629,400
40 $2,471,100 $977,200 $19,239,000 $14,123,800 $12,027,200
40 $1,323,600 $665,100 $12,736,100 $9,254,700 $7,827,600
TABLE 6
58
-------
REPUBLIC. MISSOURI SITE
FEASIBILITY STUDY
FINAL ALTERNATIVE II
DISCHARGE TO POTW
ITEM
Extraction Wells (existing)
Extraction Wells (new)
Extraction Well Pumps (5 gpm)
Ex Well Disc Plplng-2* DBL Wall PVC
Disc Piping to POTW-3* (existing)
SUBTOTAL
TREATMENT FACILITIES (150 GPM)
Flow Equalization Tank (existing)
Feed Pump to Pre-Flliers(exisilng)
Pre-Fllters
Air Stripper Package (existing)
Bicclde Feed Package
Pre-Engr Bldg (20'x 30' existing)
SUBTOTAL-TREATMENT EQUIPMENT
Piping (20%)
Electrical (20%)
Instrumentation (30%)
Civil/Site Work (15%)
TREATMENT FACILITIES-SUBTOTAL
CONSTRUCTION-SUBTOTAL
Bonds and Insurance (5%)
Bid Contingencies (15%)
Scope Contingencies (20%)
CONSTRUCTION TOTAL
Permitting and Legal (7%)
Construction Services (8%)
TOTAL-IMPLEMENTATION
Engineering Design Costs (8%)
TOTAL CAPITAL
CAPITAL COSTS
QUANTITY UNITS UNIT
PRICE
(5)
3 EA 0
4 EA 30.000
4 EA 1 ,000
0 LF 50
150 LF 0
1 EA 0
2 EA 0
1 LS 4,700
1 EA 0
1 LS 13,650
600 SF 0
TABLE 7
59
TOTAL
($)
0
120.000
4.000
0
0
$124.000
0
0
4,700
0
13,700
0
$18,400
3,650
3.630
5.520
2,760
$34,000
$158,000
7,900
23,700
31.600
$221,200
15,500
17,700
$254,400
20.400
$274,800
-------
REPUBLIC, MISSOURI SITE
FEASIBILITY STUDY
FINAL ALTERNATIVE II
DISCHARGE TO POTW
ANNUAL OPERATION AND MAINTENANCE COSTS
OPERATION COSTS
Power Costs-Assumptions: Electrical Cost - S0.06/KWHR
Pump and Motor Efficiency • 0.6
Unit Number Flow
(GPM)
Extraction Well Pump--REM-1
Extraction Well Pump--CW-1
Extraction Well Pump--SSC-3A
Extraction Well Pump--SSC-6C
Extraction Well Pump--SSC-29
Extraction Well Pump--SSC-30
Extraction Well Pump--SSC-3i
Extraction Well Pump--SSC-32
Feed Pump to Pre-Filters
Air Stripper Transfer Pump
Air Stripper Blower
SUBTOTAL-POWER
Operation Labor
(1/2 of 1 men. 2 shifts/day. 8 hour shift. 365
Chemicals
Blocide
Sewer Charges
OPERATION SUBTOTAL
MAINTENANCE COSTS
PARTS
LABOR
Treatment Facilities
(1/2 of 1 men, 1 shift/day, 8 hour shift,
Extraction Wells and Piping
(1/2 of 1 men, 1 shift/day, 8 hour shift,
MAINTENANCE SUBTOTAL
1
1
1
1
1
1
1
1
1
1
2
2920
days/year)
50
75
75
5
5
5
5
5
150
150
--
Hours
150 GPM @
1460
365 days/year)
.1460
365 days/year)
Hours
Hours
Head Total
(FT) HP
325 6.84
330 10.42
130 4.10
125 0.26
75 0.16
90 0.19
90 0. 1 9
95 0.20
30 1.89
30 1.89
3.00
@ S25.00/HR -
$ 1.25/1 OOOgal-
@ S25.00/HR -
@ S25.00/HR -
Annual
Cost
2,700
4.100
1.600
100
100
100
100
100
700
700
2.400
$12,700
73,000
10.000
98.600
$194,300
10,000
36.500
36.500
$83,000
MONITORING COSTS
Treatment Moniiorlng
Analysis
(2 Key Points, 1 time/week, 52 weeks/yr)
Groundwater Monitoring
Analysis
(Samples Taken Quarterly)
MONITORING SUBTOTAL
104 Samples @ $300.00 -
32 Samples @ $300.00 -
31,200
9.600
$40,800
OPERATIONS, MAINTENANCE. MONITORING SUBTOTAL
UNIT COST CONTINGENCIES (10%)
SCOPE CONTINGENCIES (15%)
ADMINISTRATIVE (15%)
$318,100
31,800
47,700
47,700
ANNUAL OPERATION AND MAINTENANCE COSTS
$445,300
TABLE 3
60
-------
waters at or below their ARAR levels will correspond to an excess
lifetime cancer risk at or near 1 x 10 through the exposure
routes of direct contact/ingestion.
SECTION 10.0 STATUTORY DETERMINATIONS
Under its legal authorities, EPA's primary responsibility at
Superfund sites is to undertake remedial actions that achieve
adequate protection of human health and the environment. In
addition, section 121 of CERCLA establishes several other
statutory requirements and preferences. These specify that when
complete, the selected remedial action for this site must comply
with applicable or relevant and appropriate environmental
standards established under Federal and State environmental laws
unless a statutory waiver is justified. The selected remedy also
must be cost effective and utilize permanent solutions and alter-
native treatment technologies or resource recovery technologies
to the maximum extent practicable. Finally, the statute includes
a preference for remedies that employ treatment that permanently
and significantly reduce the volume, toxicity, or mobility of
hazardous wastes as their principal element. The following
sections discuss how the selected remedy meets these statutory
requirements.
10.1 Protection of Human Health and the Environment
The selected remedy protects human health and the environ-
ment through extraction and treatment of the VOC contaminated
ground water. The contaminants will be permanently removed from
the ground water by air stripping. The volatile dissolved gases
will be transferred to the air stream for release to the
atmosphere. .
Extraction of the VOC contaminated ground water also will
eliminate the threat of exposure to the most mobile contaminants
from direct contact or from ingestion of contaminated ground
water. The future carcinogenic risks associated with these
exposure pathways are as high as 1.1 x 10~ , or one person in
ten, for TCE. By extracting the contaminated ground water and
treating it by air stripping, the cancer risks will be reduced to
about 1 x 10~° and an Hazard Indices (HI) ratio of less than 1.
A numerical computer model was utilized to predict the highest
airborne concentrations emitted from the air strippers. The
location with the highest concentrations was used to evaluate
potential health risks. The highest cancer risk is 6.5 x 10-6
and the highest HI ratio is 0.3997. These levels are within the
range of acceptable exposure levels of between 10~4 and 10 and
an HI ratio of less than 1. There are no short-term threats
associated with the selected remedy that cannot be readily
controlled. In addition, no adverse cross-media impacts are
expected from the remedy.
61
-------
10.2 Compliance with Applicable or Relevant and Appropriate
Requirements
The selected remedy of extraction, onsite physical/chemical
treatment, and discharge of the treated effluent to the POTW will
comply with all applicable or relevant and appropriate chemical,
action, and location specific requirements (ARARs). The ARARs
are presented below.
Action-specific ARARs:
National Primary and Secondary Ambient Air Quality
Standards (40 CFR Part 50)
State air quality De Minimis Emission Levels
[10 CSR 6.060(7)(A)];
State water quality standards for aquatic life
protection (10 CSR 20-7.031) incorporated into the
NPDES permit for the POTW discharge to Dry Branch;
National Pretreatment Standards, 40 CFR Part 403;
and,
Pretreatment standards of 200 ug/1 and 200 gpm
established by the City of Republic for the
• discharge of treated SSC effluent to the POTW.
Chemical-specific ARARs:
Federal Maximum Contaminant Levels for inorganic and
volatile organics in drinking water supplies
(40 CFR Part 141) ;
State Maximum Inorganic Chemical Contaminant Levels
(10 CSR 60-4.030) for public water systems;
State Maximum Volatile Organic Chemical Contaminant
Levels for public water systems (10 CSR 60-4.100);
and,
State water quality standards for inorganic and
volatile organics in ground water (10 CSR 20-7.031).
Location-specific ARARs:
None
Other Criteria, Advisories or Guidance To Be Considered for This
Remedial Action (TBCs):
62
-------
EPA and the State of Missouri have agreed to
incorporate a local ordinance to prohibit construc-
tion of new water supply wells in or near the con-
taminant plumes until the remediation is complete.
This will prevent direct contact and/or ingestion of
contaminated ground water.
10.3 Cost-Effectiveness
The selected remedy is cost-effective because it has been
determined to provide overall effectiveness proportional to its
costs, the net present worth value being $4,629,400. The select-
ed remedy is the least costly of the Alternatives II, III and IV,
which are equally protective of human health and the environment.
10.4 Utilization of Permanent Solutions and Alternative Treatment
Technologies (or Resource Recovery Technologies)' to the
Maximum Extent Practicable
The State of Missouri and EPA have determined that the
selected remedy represents the maximum extent to which permanent
solutions and treatment technologies can be utilized in a cost-
effective manner for the Solid State Circuits Site. Of those
alternatives that are protective of human health and the
environment and comply with ARARs, the State of Missouri and EPA
have 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,
cost, also considering the statutory preference for treatment as
a principal element and considering State and community input.
Alternative II reduces the toxicity, mobility, and volume of
the contaminants in the ground water; complies with ARARs; pro-
vides short-term effectiveness; and protects human health and the
environment equally as well a Alternatives III and IV. In terms
of long-term effectiveness, Alternative II is more reliable
backup to the stripper units and because it does not generate any
residuals. Alternative II will be easier to implement techni-
cally because it requires less construction and administratively
because it will require less coordination with relevant agencies.
Finally, and importantly, Alternative II costs the least of the
equally protective alternatives. The major tradeoffs that pro-
vide the basis for this selection decision are long-term effec-
tiveness, implementability, and cost. The selected remedy is
more reliable and can be implemented more, quickly, with less
difficulty and at less cost than the other treatment alternatives
and is therefore determined to be the most appropriate solution
for the contaminated ground waters at the SSC site.
63
-------
The State of Missouri is in concurrence with the selected
remedy. Although public comments were received concerning the
capacity of the community's POTW, those comments are fully
addressed in the Responsiveness Summary.
The Proposed Plan for the SSC site was released for public
comment on August 14, 1989. The Proposed Plan identified
Alternative II as the preferred alternative. EPA reviewed all
written and verbal comments submitted during the public comment
period. Upon review of these comments, it was determined that no
significant changes to the remedy, as it was originally
identified in the. Proposed Plan, was necessary.
10.5 Preference for Treatment as a Principal Element
By treating the VOC-contaminated ground waters in two
existing onsite air strippers and discharging the treated
effluent to the POTW for secondary treatment, the selected remedy
addresses the principal threat of future direct contact/ingestion
of contaminated ground waters posed by the site through the use
of treatment technologies. Therefore, the statutory preference
for remedies that employ treatment as a principal element is
satisfied.
64
-------
APPENDICES
65
-------
APPENDIX A
66
-------
NUMERICAL VALUES OF CONTAMINANT-SPECIFIC ARARS FOR COMPOUNDS DETECTED IN GROUNDWATER
Contaminant
OnGANICS
Aciulum
Baruene
Btt<2-Elriy1huxyl)phir)«lal*
Bulyl Barnyt PhUialal*
Criloio6en;une
Chlor oat/taut*
Chlorolotm
l.l-OicliloiooUiona
I 1-OichloiouUiena
1 .2-DichlufOtt Inane
l.2-Oicliloulny1ene
l.2-Oicliloiupiop«ne
1.3-Dichloiujiiuf>>1»ne
EUiyUiun/una
(•O)>hoione
MttUiyl Chlojlde
MtfUiylonu Chlonde
Plienot
T«li«cliloitM>ltien*
Taluentt
liani- 1 2-Oiclilix outdone
I , I , I - 1 iiihloiuulhana
IncliloKMilhonu
1.1.2- liit:hloi<>olhan<»
Vinyl Cliluiiilu
SOWA
MCL
ing/I
0005
• '
0 1
0005*
0007
0 DOS
•
0
•
0 7
0005
•
2
0 2
0005
0 001'
SOWA
MCLG
(1)0/1
0
ooe*
0007
0
0005
•
0 1
•
0
•
2
007
0 2
0
0
EPA
SMCL
ing/1
003*
003
MISSOURI
MCL
ing/I
0005
0007
0005
0 2
OOOS
0 UO2
MISSOURI
SMCL
nig/1
- -- - -
STAIE OF MISSOURI*
WATER QUALITY
STAND AflOS
1
mg/l
0 32
0 1
- -
VI
ing/1
032
000066
002
0 00004
007
00008-1
0087
52
000010
01
ooooe
ll 2
0 0027
0002
VII
mg/l
032
000066
002
0 00094
0 00004
0 087
5 2
0000 10
03
00008
00027
0 002
EPA AMDIENT WATER QUALITY CRITERIA
For Toxic
Ingesting
Wului and
Oigaiiiane
mg/l
038
15
0 488
00141
000019
36
14 3
0033
00184
0002
^folocllon
IngoEting
Oiyanlunn
Only
ing/I
0 78
60
1505
0087
00157
760
424
OOOID5
0 00103
o :,:•:,
Foi Caicl
Ingablirig
Walui and
Oigunitunt
ing/I
000066
•
0 00010.
0 000033
000004
1 4
0 0008
0 0027
0 00(1
Piolacliui'
Ingeeling
Otganibne
Only
ing/I
004
00157
000185
0 243
328
0 00885
0 080/
0 0418
EPA AMBIENT WATER
QUALITY CRITERIA FOR
PRO IECTION OF FRESH-
WAI EH AQUATIC LIFE
AculB
rng/l
b
0068
b
53
b
004
33
105
28 0
II 6
b
118
1>
23
b
eoa
b
32
b
5SO
r
103
102
528
b
1/5
£
11 0
b
18
b
45
Chronic
nig/I
b
0021
0003
0 22
b
1.24
b
20
b
5 7
b
0244
256
b
0 84
21 9
-------
NUMERICAL VALUES OF CONTAMINANT-SPECIFIC ARARS FOR COMPOUNDS DETECTED IN GROUNDWATER
cr>
CD
Contaminant
METALS
Cadmium
Chiomium
Copper
Lead
Mercury
Nlckot
Zinc
PESTICIDES AND PCQS
PCB-1254
SOWA
MCL
nig/1
001
005
005
005
0002
•
05
SOWA
MCLG
my/1
0005
•
0 t
•
1 3
002*
0002*
•
0
EPA
SMCI
mg/l
5
MISSOURI
MCL
rng/l
001
005
005
0002
MISSOURI
SMCL
mg/l .
1
SI Alt OF MISSOURI8
WATKH QUALITY
STANDARDS
1
ing A
00012
005
002
005
T
00005
O.I ^
0 1
VI
nig/1
0 0012
005
002
005
00005
0 1
2
VII
nig/1
ooot
005
1
005
0002
02
01
EPA AMBIENT WATER QUALITY CRITERIA
For Toxic Protection
Ingutllng
Water and
Orgu/ilwrii
my/1
001
005
005
0000144
00134
Irigetling
Organlwnu
Only
mg/1
0 000146
0 1
Foi Caret Protection
Ingoeting
Waler and
OigaiiluMt
mg^
Ingesting
Organ! wne
Only
mg/l
EPA AMBIENT WATER
QUALITY CRITERIA FOH
PROTECTION OF FRESH-
WATER AQUATIC LIFE
Acute
mg/l
0 0018
0 016
d
0 018
0082
0 0024
1 1
0 16
Chronic
mgl
0 0066
00011
d
0012
00032
00012
0058
0047
Nulei:
Blank a Indicate data U not available
•
Proposed value
b
InaulAclent dala lo develop criteria Value hsltxl U Uio I owed ObburveO Ellecl Luvol (L O fc L )
c
Thccrileilon loi caiclnogeni it 1010. Iliu cilleilon givun coirecpcxidt lu ail excec» carcinogen ritA ol 1 x 10-0
d
HardnetK dependent criteria Value Imled li ba«e k'llMVII Wtlldl » MBllll ftM.Ilttfl)e
VII (n. Min.l^alaf mtli nu k'K^wii builai.u wnlin UH fittrgti
I
-------
APPENDIX B
69
-------
SUMMARY OF CHEMICALS DETECTED
CD
Consiituenl
Max
Detected Ground Water
(mg/L)
Mclals
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Zinc
Volatile Organic Chemicals
Acrolein
Benzene
Chlorobenzene
Chloroelhane
Chloroform
, 1 -Dichloroelhane
,2-Dichloroelhtne
,1-Dichloroelhene
,2-Dichloropropane
,3-Dichloropropylene
E4hylberuer>e
Melhylchlohde
Melhylene chloride
Tcinchloroeihene
Toluene
Trans- 1 ,2-Dichloroethene
1,1,1 -Trichloroeihane
1 , 1 ,2-Trichloroelhane
Trichloroelhcne
Vinyl chloride
1.2-Dichloroelhene
Acetone
.021
.19
055
.007
.0002
.08
3.77
.043
.0048
.Oil
63
.012
.890
.044
1.0
.004
.0071
.016
.027
36
.180
15
3.1
14.0
.076
290.0
.410
.058
.081
imum Reported
Soil
-
- -
-
-
-
—
.46
-
_
.Oil
.020
_
110
' -
. -
.0026
-
2.7
.069
.0078
0.18
.110
.0057
4.2
.0037
-
Concentration
POTW Ellluent/
Surface
Water
(mjns to NK'Ls, KIDs. and occuiiem'c in cnvn
. NC Noncatcinojien via injieMion
NA N"l BMihiHc
ii-mal i
-------
APPENDIX C
71
-------
CRITERIA FOR CHARACTERIZATION OF POTENTIAL CARCINOGENIC
EFFECTS FOR THE INDICATOR CHEMICALS
Chemical
1 ,1-Dichlorocihana
1,1-Dichloroeihene
Methylene chjorida
TrichJoroethene
Vinyl chloride
Cancer
OraJ
(mg/kg/day)-l
9.1E-2 (b, j, i)
6E-I (a)
7.JE-3 (•)
ME-2(a)
2.3 (c.d)
Potency Factors
Inhalation
(mg/kg/dayM
—
1.2d)
1.42E-2
4.6E-3 (b.c.e)
2.95E-I (b)
lO*
Cancer Rick fh)
(mg/L)
.0004
0.033
0.003
2.7
.00015
EPA
Weight of
Evidence
C
- C
B2(i)
B2(i).
A(c)
(i) EPA 1987c
(b) EPA 1987e
(c) EPA 1986*
(d) EPA 1984c
(e) EPA 19844 '
(0 The oral cancer potency factor Cor 1,1-dichloroeihjnc is bised on aructure-actjviiy relationships to l*2-dichloroeihane
(EPA I988a).
(S) EPA 1988a
(h) Conceniratioa would probably result in 1 additional cancer in 1,000,000 population drinking 2 liters of water per day over
a 70-vear lifetime.
72
-------
CRITERIA FOR CHARACTERIZATION OF POTENTIAL NONCARCINOGENIC
EFFECTS FOR THE INDICATOR CHEMICALS
Chemical
1 , 1 -Dichl.ir.xMhanc
1 . 1 -Dichlorocihcne
Trans- 1 ,2-Dichlorocthcne
Mclhvlcnc chloride
1,1.1 •Trifhlorocihanc
Trichlorncthcne
Vinyl chlorijj
RfT) (nig/kg/day)
Oral
I.2E-I*
9.0E-I
I.OE-2
6.0E-2
9.0E-2
7.35E-3
I.3E-I
RfT) (mg/VK/rtay)
(source) Inhalation (source)
EPA'l988a 1.38 E-l EPA I98fta
EPA 1987d . -
EPA I987g —
EPA I987d —
EPA I987i 3.0E-I EPA I986a
EPA I987e
EPA I987a —
--- Nol available
a Ahhrcvialion for scientific nrxalion I.2E-I = 1.2 x 10
73
-------
APPENDIX D
74
-------
Exposure Scenario
POTENTIAL HUMAN HEALTH RISK SUMMARY
(CURRENT CONDITIONS)
Adnft
Chfld
Infant
Dermal Conuct/Iogestioo
OfT-SKe Subsurface Sofl
Cancer Risk
Noncarcinogenic Risk
DermaJ Contact/legation
Subsurface Sofls on Mala Street
Cancer Risk
Noncarcinogeruc Risk
1.1x10"
0.001
2.9 x 10"8
(5.6 x 10~V
0.012
(0.021)*
2.9 x 10'
0.001
2.Ox 10
0.0004
-10
Dermal CoaUct with
Surface Water from POTW
Cancer Risk
Noncarcinogeruc Risk
<1.0x 10
<0.00
-10
-10
<0.00
Dermal Contact with
Surfact Water from UtflltT (TOTW Influent)
Cancer Risk
Nooca/cinogenic Risk
<1.0x 10
<0.00
-10
Dermal Contact with
Surfact Water from Utility (Away from Main Street)
Caocer Risk
Noncarcinogenjc Risk
<1.0x 10
<0.00
10
DcrmaU Contact with
Surface Water from UttUrr/Tekphoot Manbolo
Cancer Risk
Noncarcinogeroc Risk
<1.0x 10'
<0.00
,-10
Inhalation of AJrborae Oxmlcali
from Stripping Tower
Cancer Risk
Noncarcinogeruc Risk •
6.5 x 10
0.2284
5.6x 10
0.4010
1.6 x 10
0.3997
•Health risk levels associated with clayey toili
75
-------
CUMULATIVE POTENTIAL HUMAN HEALTH RISKS FOR A MUNICIPAL
SEWER WORKER LIVING NEAR THE SITE
Exposure Cancer Noocardnogenk
Scenario Risk Risk
Dermal Contact/
logestion of
OfT-Sile
Subsurface Soil l.lxlO"8 0.001
Dermal Contact/
Digestion of
Subsurface Sod 2.9 x 10~8 0.012
on Main Street (5.6 x 10~V (0.021)4
Inhalation of Airborne
Chemicals from toe
Stripping Tower 2.3x10 0.016
Toul Risk 2.3 x 10"6 0.029
(2.3 x 10"*)' (0.038)'
*
NOTE: • • Health risk level issociited with clayey soils.
76
-------
POTENTIAL HUMAN HEALTH RISK SUMMARY
(FUTURE CONDITIONS)
EXPOSURE SCENARIO
ADULT
CHILD
INFANT
Dermal Cootad/IngestJoo
On-Site Surface Soil
Cancer Risk
Noncarcinogenic Risk
Dermal Contact/To gestion
On-Site Subsu.-'jce Soil
Cancer Risk
Noncarcinogenic Risk
Dermal CoaUcx/Iogesdou
On-Site LTFSB Ground Water
Cancer Risk
Noncarcinogenic Risk
Dermal Cootactlngestion
On-Site SBR Ground Water
Cancer Risk
Noncircinogeru'c Risk.
Dermal CooUd/Ingestfon
On-Siie DBR Ground Wiier
Cancer Risk
Noncarcinogenic Risk
Dermal Cootact/Ijigestloa
Off-Site Main Street Area UFSB Ground Wiwr
Cancer Risk
Noncarcinogenic Risk
Dermal CooLact/Ingestioa
Off-Site Main Street Area SBR Ground Water
Cancer Risk
Noncarcinogenic Risk
3.9xlO"8 2.0xlO"9 l.OxlO'10
0.0004 0.0003 0.0002
-
5.7x10'* 3.6x!0"9 6.0x10"'°
0.149 0.124 0.062
4.6xlO"2 1.6xlO"2 2.3x10°
191 383 335
MX 10"' 3.9xlO"2 5.7x!0'3
1144 2292 2005
9.0xlO"3 3.0xlO'3 4.5X10"4
71.3 143 115
3.2 xlO"3 l.lxlO"3 1.6x10"*
30 61 53
6.6 x IO'3 2.3x 10"5 3.3 x 10"*
O.SI6 1.63 1.43
77
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POTENTIAL HUMAN HEALTH RISK SUMMARY
(FUTURE CONDITIONS) (CONTD)
EXPOSURE SCENARIO
ADLTT
CHILD
OcrmaJ CoaUct/Ingestioa
Off-Site Main Sireel Area DBR Ground Wntr
Cancer Risk
Noncarcinogenic Risk
4.1 * 10
3.53
8.2 x 10
7.05
2.0 x 10
6.17
5
DermaJ Cootactlngestfoo
Off-Site Awav From Main Sireel UFSB Ground Wner
Cincer Risk
Noncircinogenic Risk
3.0x10
0.04
l.Ox 10
0.07
1.4x 10
0.06
Dermal Cootact/Iflgesdoo
Aw«v From Main Sireel SBR Ground Wiier
Cancer Risk
Noflcarcinogenic Risk
3.9x 10
0.02
-3
1.3 x 10"'
0.05
1.9x 10
0.04
DemuJ CoaUd/lngadoo
O(T-Siie Away From Main Street PBR Ground Water
Cancer Risk
Noncarcinogenic Risk
no carcinogens
no indicator chemicals
78
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RESPONSIVENESS SUMMARY '
RECORD OF DECISION
FOR THE
SOLID STATE. CIRCUITS SITE
REPUBLIC, MISSOURI
SEPTEMBER 1989
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RESPONSIVENESS SUMMARY
TABLE OF CONTENTS
PAGE
1.0 OVERVIEW 1
2.0 BACKGROUND 1
3.0 SUMMARY OF COMMENTS RECEIVED DURING 3
• PUBLIC COMMENT PERIOD
A. REMEDIAL ALTERNATIVE PREFERENCES 3
B. TECHNICAL QUESTIONS/CONCERNS REGARDING 6
REMEDIAL ALTERNATIVES
C. PUBLIC PARTICIPATION PROCESS 27
D. COST/FUNDING ISSUES- .27
4.0 COMMUNITY RELATIONS ACTIVITIES 28
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SOLID STATE CIRCUITS SITE
REPUBLIC, MISSOURI
RESPONSIVENESS SUMMARY
1.0 OVERVIEW
In the Proposed Plan released to the public, the Missouri
Department of Natural Resources (MDNR), with EPA concurrence,
made a preliminary selection for the preferred alternative.
MDNR's recommended alternative addressed the ground water contam-
ination problem at the site. The preferred alternative involved
extraction and containment of the contaminant plumes using
existing and new wells, treatment of the extracted water using
existing onsite air strippers and discharge of the treated water
to the publicly owned treatment works (POTW) for further treatment.
Judging from the comments received during the public comment
period, the residents and several city aldermen of Republic, and
the Greene County Commission generally did not favor the
preferred alternative as presented. The Greene County Commission
clearly stated that they favored the discharge option to the POTW
but with a combination of Alternatives II and III, which would
combine metals removal, air stripping, and carbon adsorption
prior to discharge of the treated water. Republic residents and
aldermen did not clearly state their preference for discharge;
however, an analysis of the transcript of the public meeting
generally showed that residents either wanted a new sewage treat-
ment plant built exclusively for the SSC discharge or to use the
POTW, provided the metals are removed in order to ensure there
would not be a problem with dispo.sal of the POTW sludge. POTW
concerns centered around how the treatment capacity would be
affected by the site discharge and whether metals would upset the
balance of the POTW. One alderman asked for an analysis of what
would happen to the sewage treatment plant as far as possible
breakdown of the algae.
The PRPs supported the preferred alternative as described in
the Proposed Plan.
2.0 BACKGROUND ON COMMUNITY INVOLVEMENT
Community interest in the Solid State Circuits Site (SSC)
dates back to 1983 when residents of Republic were first notified
that trichloroethene (TCE) had been detected in Municipal Well
Number 1 and the distribution system. The Solid State Circuits
Site is important to the 6,300 residents of Republic because of
its effect on the water supply. When Well Number 1 was taken out
of service, the City was forced to rely on its two remaining
wells, Numbers 2 and 3. These two wells were adequate to meet
daily demands, but if the larger of the two remaining wells had
-------
to be shut down, the amount pumped would be less than the average
daily use. One of the town's main industries, home building, was
at a standstill because there was not enough water for new
subdivisions.
City officials and a number of interested citizens in the
community were actively involved in seeking remedies to the
situation. A special task force was formed to resolve the town's
water supply problems. The town's mayor and city council members
tried to put together matching money for a water grant from MDNR,
but the Missouri Legislature failed to appropriate funds for the
water grants program for Fiscal Year 1987. The MDNR met with.
city officials several times to discuss options for resolving
water supply problems; however', they could not provide the city
with any money.
The MDNR conducted phone and personal interviews with
interested residents from February through April 1986. The key
concerns identified were:
Adequate Water Supply
The town was concerned about having enough water since City
Well Number 1 was not in use. A related concern was the fear
that one of the city's other two wells might become contaminated.
This would create an immediate water crisis for the town.
Consumption of Contaminated Water
Some residents had little faith in the monthly testing of
Well Numbers 2 and 3. They believed that the water could already
be contaminated, and that they could be drinking contaminated
water. They doubted that anyone would really tell them if the
water was contaminated.
Long Term Health Effects
Residents were concerned about whether they would experience
any adverse health effects from the TCE found in the city's water
supply. The contaminated well was shut down before levels of TCE
reached unsafe levels, but nonetheless, residents wondered if
they would experience long-term health problems.
Spread of Contamination
Some residents were concerned that continued operation of
the city's other two wells might be spreading the contamination.
They wondered about the present extent of contamination and the
possibility that private wells might become contaminated.
-------
Time Frame
Many citizens were concerned about the length of time it
might take to get a new well and the length of time required for
cleanup. They wanted to. see faster progress on both issues.
Economic Impact
Water supply problems posed a big threat to the town's
economic health. A moratorium on the construction of new
buildings and subdivisions was in effect. Local building
contractors were faced with laying off workers if the water
supply problems were not resolved. This would cause the town's
economic growth to come to.- a halt.
Responsible Party
Residents indicated they felt the responsible party should
shoulder more of the burden in helping the city to resolve its
water supply problems. They were concerned that the responsible
party would escape some of its obligations to the community.
Solid State Circuits, Inc. did contribute funds toward the con-
struction of Municipal Well Number 4, which was brought on line
in 1988. This helped alleviate some of the community's concerns
about an adequate water supply, and the construction moratorium
was lifted.
Lack of Information
Most people wanted to see more information available. As
citizens became more-knowledgeable about the site, they felt a
need for more technical information. They also wanted to be
updated regularly on the situation.
3.0 SUMMARY OP COMMENTS RECEIVED DURING PUBLIC COMMENT PERIOD
Comments raised during the public comment period on the
draft Feasibility Study (FS) and proposed plan are summarized
briefly below. The comment period was held from August 14 to
September 14, 1989. The comments are categorized by relevant
topics.
A. Remedial Alternative Preferences
Each of the major commentaries on the draft FS expressed a
preference for specific alternatives:
1. The members of the Greene County Commission read a
statement at the public meeting in support of a
combination of both Alternatives II and III.
Alternative II was appealing to the Commission because
it affords treatment of the contaminants, and the
-------
ultimate discharge is to the POTW. Alternative III is
appealing in that it removes the metals and utilizes a
process of both carbon adsorption and air stripping.
The Commission wanted the combined alternatives to
include the treatment of heavy metal contaminants, air
stripping of the volatile organic compounds (VOCs), and
carbon absorption, with the ultimate discharge from
these activities being delivered to the POTW.
2. A citizen wrote a comment letter in support of
Alternative III. He felt that the discharge of treated
water from Alternative II would be overloading the
City's sewage disposal system. He was concerned about
the disposal system being unable to handle, the-City's
residential and business waste.
3. Another citizen stated in writing that Solid State
Circuits should build and operate a separate
pretreatment plant to remove the solids from the water
and, if Republic's sewage disposal plant can handle the
extra liquid, put the water in the disposal system. He
also wanted SSC to pay a higher rate than the.residents
of Republic to use the disposal system.
4. Solid State Circuits, Inc. wrote a comment letter in
support of Alternative II for several reasons:
a) Alternative II provides a comprehensive
remediation plan and utilizes proven
remediation technologies and methods;
b) Discharge to the POTW provides a backup
treatment capability, whereas Alternatives III
and IV do not;
c) During the RI/FS and Pilot Study, remediation
under Alternative II has already begun and can
continue without interruption, providing
remediation as opposed to more study and delay
that would result from selection of
Alternatives III or IV.
d) Selection of Alternative II will result in
little or no disruption to the citizens and
streets of the City of Republic, since a
discharge line from City Well Number 1 to the
Main Street sewer line was completed earlier
this year. Selection of Alternative III would
require a dedicated discharge line constructed
through the heart of the city. This would be
very disruptive to the citizens and to traffic
flow;
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e) Alternative II will generate approximately
$90,000 per year to the City of Republic (based
on a charge of $1.25 per 1000 gallons and a
discharge of 150 gpm). Black & Veatch
Engineers, an engineering consulting firm, has
estimated that the operation and maintenance
costs at the flow through portions of the
Republic POTW system to be $0.5416 per 1000
gallons and a capital allocation for the
Treatment Plant of $0.1743. This results in a
combined cost to the City of Republic of
$0.7159, with estimated income to Republic of
$0.5341 per 1000 gallons. These allocations
and estimates were based on the- Republic User
Charge Ordinance No-84-1007. If Alternatives
III or IV are selected, very little, if any,
money would be paid to the Republic POTW since
the system would be bypas.sed after implementa-
tion of the final remedy;
f) SSC and the City of Republic have entered into
an agreement that allows SSC to discharge
treated effluent from the site (up to 200 gpm)
to the sewer system and provides that SSC will
reimburse the City of Republic for any increase
in actual charges paid by the city for disposal
of sludge from the POTW. This agreement was
originally agreed to in late 1986 and was
recently amended by unanimous vote of the City
Board of Aldermen on June 12, 1989;
g) Implementation of Alternative II will not
impact the City of Republic's POTW ability to
treat suspended solids and/or impact the
biological oxygen demand since there will be no
discharge of "sewage" from the site; and,
h) Alternative II is more cost effective and best
achieves the goals of the National Contingency
Plan.
MDNR/EPA Response;
The agencies previously considered the need for metals
removal and carbon absorption for Alternative II and the impact
of Alternative II on the treatment plant. The responses are
given in the following subsection entitled "Technical
Question/Concerns Regarding Remedial Alternatives;" specifically,
Question Numbers 1, 2, and 4. In summary, metals removal or
carbon adsorption is not needed for Alternative II. The SSC
discharge will not adci to the treatment capacity load on the
POTW, since the discharge will have no significant organic and
-------
solids load associated with it. The comments received orally and
in writing did not cause MDNR or EPA to alter their technical
decisions about the site. The public did have valid concerns and
comments, but they were issues which had been previously
considered by both agencies.
Response to the PRPs comment letter:
a) Alternative III uses metals removal and carbon
adsorption, which are both proven technologies.
Alternative IV uses carbon adsorption and reinjection of
the treated effluent to the deep bedrock aquifer as part
of an enhanced ground water contaminant recovery system.
Enhanced ground water contaminant recovery has not been
widely used in the state' as a means of plume management;
b) Carbon adsorption provides the secondary treatment for
Alternatives III and IV;
c) Remediation can be started quicker with Alternative II,
since most of the remedial components are already in
place. Alternative III will require onsite construction
of the metals removal unit and the carbon adsorption
unit and construction of the two mile long discharge
pipeline to Shuyler Creek. Alternative IV will require
onsite construction of the,carbon adsorption unit and
offsite construction of the reinjection wells. Addi-
tionally, more time will be needed to determine the most
effective locations of the reinjection wells;
d) Implementation of Alternative II will require the con-
struction of four new offsite extraction wells and
pipelines from offsite wells to carry the extracted
water back to the air strippers, but this same construc-
tion is also required for Alternatives III and IV. This
construction will not disturb the community as much as
construction of Alternative Ill's two-mile pipeline or
Alternative IVs reinjection wells; and,
e-h) MDNR/EPA have no specific responses to these comments.
B. Technical Questions/Concerns Regarding Remedial
Alternatives
Question 1.
There were several questions asking why metals removal was a
part of Alternative III but not Alternative II, and what effect
metals, particularly copper, would have on the POTW.
-------
Additionally, Solid State Circuits, Inc. had the fol-
lowing comment in their written comment letter regarding metals
removal.
"Metals removal from the effluent would require
implementation of a treatment technology (metals precip-
itation) that is unnecessary and impractical for this
site. It is very likely there would be no reduction in
the metals' levels and would potentially create an air
emissions problem and generate sludge that would have to
be stored, transported and disposed at an approved
facility. This type of approach is inconsistent with
the long-term environmental policy of the EPA and the
State of Missouri. It is unreasonable and not practical
to implement a metals removal system to reduce copper
levels from 55 ug/1 to below 29 ug/1. These levels
already approximate the levels permitted under the Safe
Drinking Water Act Maximum Contaminant Level of 50 ug/1
and a proposed Maximum Contaminant Level Goal of 1,300
ug/1. As a point of fact, the Southwest Treatment plant
of the City of Springfield allows industrial users to
discharge over 2,000 ug/1 of copper to the sewer with no
adverse impact on Springfield's POTW."
MDNR/EPA Response;
Table 4-3 of the Remedial Investigation (RI) Report
(pages 4-9) presents the detected maximum, detected minimum, and
detected average of metals in ground water samples. Part of that
table is reproduced below. The metals reportedly in the SSC
waste stream at the time of operation were chromium, copper,
iron, manganese, and zinc.
No.Detected/
Metals (ug/1) ' Maximum Minimum Average No. Sampled
Chromium 190.0 190.0 190.0 ( 1/35)
Copper . • 55.0 5. 19.3 (15/54)
Zinc 3770.0 10.0 490.6 (18/83)
Iron 47700.0 60.C 5300.0 (39/91)
Manganese 32900.0 20.0 5230.0 (22/48)
Chromium was detected only once in thirty-five samples, and
subsequent sampling of the location with the 190 ug/1 concen-
tration produced nondetectable concentrations. The only samples
with detectable levels of copper were municipal water supply
wells, not onsite wells. Copper is endemic to municipal water
supplies because of all the copper fittings, pipes, impellers,
etc., which are used in the distribution system. Additionally,
many residential homes have copper water pipes, which contribute
copper to the water. Zinc is present at elevated levels onsite.
Iron and manganese occur naturally in ground water, so the higher .
iron and manganese levels may not be attributable to the site.
-------
The 1987 Census of Missouri Public Water'Supplies, Chemical Water
Quality Section, shows that the Republic's public water supply
had iron present at less than 100 ug/1 and manganese at less than
20 ug/1. However, these concentrations were from drinking supply
wells, which were designed, installed and developed differently
from monitoring wells such as the ones used in the RI. Properly
installed drinking supply wells effectively screen metals from
entering the drinking water supply. Thus, the 1987 Census levels
are not an appropriate indicator of actual iron and manganese, in
the aquifer.
For Alternative II,. a. metals removal step is not required
for several reasons:
(a-) The metal concentrations are far below the appropriate
pretreatment standards. The following pretreatment
standards apply to electroplating and metal finishing
industries (EPA Guidance Manual for Electroplating and
Metal Finishing Pretreatment Standards, February 1984)
and are metal levels which these industries attempt to
achieve using metals removal systems before discharging
to a POTW:
retreatment
Metals (ug/1) Standard
Chromium 1,710
Copper 2,070
Zinc 1,480
Iron
Manganese
Pretreatment standards for iron and manganese do not
exist and, thus, are not enforceable;
(b) The POTW should remove up to fifty percent (50%) of the
metals in the waste stream before discharging to Dry
Branch;
(c) Discharge to the sewer will reduce the concentrations
due to dilution to approximately twenty-five percent
(25%) of the original site concentrations. This factor,
in addition to, (b) will reduce the known metal concen-
trations presented in the first table to below stringent
aquatic-life criteria which are presented later in this
response; and,
(d) The NPDES effluent requirements for the Republic POTW do
not include criteria for the metals of discussion.
-------
Concerns were voiced in the public meeting regarding the
effects that the metal levels will have on'the POTW, particularly
copper. For an activated sludge based POTW such as Republic's,
the following inhibition levels are presented for the metals of
concern (EPA Guidance Manual on the Development and Implementa-
tion of Local Discharge Limitations Under the Pretreatment Pro-
gram, December 1987):
Inhibition
Metals (ug/1) Level
Chromium 1,000 - 100,000
Copper 1,000
Zinc 5,000 - 10,000
Iron
Manganese
Again, the metals concentrations in the SSC discharge are far
below these limitations. Eighty percent (80%) of the site
pumping will come from the same deep aquifer which the city draws
its water supply. Thus, in terms of metals, the site's discharge
will closely resemble the water currently treated by the POTW.
Additionally, the POTW has not experienced an "upset" during the
pilot study or during the extended pumping of City Well Number 1.
Both of these activities discharged significant volumes of water
to the POTW similar to what is expected in the SSC waste stream.
Alternative III includes a metals removal option; because,
it is anticipated that the direct discharge to Shuyler Creek will
need to meet stringent discharge limits for metals. The exact
limits and parameters will not be known until the application is
submitted to the MDNR for evaluation, but generally, for a low-
flow stream, like Shuyler Creek, which provides little dilution,
the permit limits will be at or slightly higher than the Missouri
water quality standards for aquatic life protection. Enclosed is
a copy of these standards. The aquatic life protection numbers
are shown in Column I. Assuming no dilution by the creek and
further assuming that chronic toxicity values, general warm water
fishery values, and a hardness category of 125-200 mg/1 will be
used, the NPDES permit limits could be very similar to the
following values:
Metal Level fug/1) • •
Chromium 42
Copper 29
Iron 1,000
Manganese Value to be determined by MDNR
Zinc .345
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If the receiving stream provides significant dilution, the
metals' limits could be higher than the values given as examples.
-Also, the naturally occurring level of metals in the receiving
stream will be considered when selecting the metals' parameters
and limits for the NPDES permit.
For Alternative IV, the reinjection of treated water as part
of an enhanced ground water contaminant recovery to the deep
bedrock aquifer will need to meet the Missouri water quality
standards established for ground water which does not recharge
surface water. These standards are shown in Column VII of the
enclosed regulation. The values are:
Metal Level fug/1.)
Chromium 50
Copper 1,000
Zinc 2,000
Iron 300
Manganese 50
It is unlikely that the chromium value will be above
50 ug/1, since the 190 ug/1 concentration was only detected in
one out of 35 samples. The iron and manganese values in the
treated water may require metal removal if the levels are signif-
icantly above naturally occurring background levels before the
treated water can be reinjected as part of an enhanced ground
water contaminant recovery.
Question 2.
The majority of questions asked in the public meeting
concerned how the increased flow from the SSC site would affect
the treatment capacity of the Publicly Owned Treatment Works
(POTW). Many residents and city officials felt the site
discharge was shortening the projected life of the POTW.
MDNR/EPA Response:
The Republic POTW has a design flow (treatment capacity) of
926,880 gallons per day (gpd) and a peak flow (hydraulic
capacity) of 7.34 million gallons per day (mgd). The hydraulic
capacity was set to accommodate flows caused by known infiltra-
tion and inflow problems of the sewer system. More importantly,
the treatment capacity is the flow which the POTW is designed to
treat within discharge criteria set by the State in the NPDES
permit. The treatment capacity is based upon the following two
design parameters: organic load and solids load.
Alternative II involves discharging treated ground water
from the SSC site to the sewer. The organic and solids load
associated with this discharge water is essentially zero. The
10
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SSC discharge water is similar to plain water in total organic
and solids load, and very unlike the sewer discharge coining from
domestic and commercial sources. In other words, the SSC
discharge will not add to the treatment capacity load on the
POTW.
With the high hydraulic capacity, the plant can accept an
actual flow larger than the treatment capacity without upsetting
operations as long as the organic and solids loads are not
surpassed, and the plant's operational procedures are modified to
meet NPDES effluent criteria. The SSC discharge (216,000 gpd)
will increase the total flow to the POTW by twenty-nine percent
(29%) or a total flow of approximately 966,000 gpd (based on
current POTW usage of 750,000 gpd). This flow increase may
require an adjustment to the current POTW operating procedures.
Adjusting operating procedures is considered normal practice as
the actual flow changes during the life of a POTW.
The Republic POTW was built with EPA and MDNR oversight and
financing through the EPA Construction Grants Program. POTWs
built through this program were very conservatively designed to
keep operator oversight requirements to a minimum. Consequently,
the treatment capacity was typically rated lower than the plant
could handle if operated differently. Specifically for the
Republic POTW, the aerator is the limiting unit in determining
the treatment capacity. The retention time for sewer water in
the brush aerator unit was designed to be 23.8 hours. Reducing
the retention time increases the flow through the aerator and
increases the treatment capacity as long as the flow receives
adequate treatment. Design and field experience has shown that
this type of aerator provides adequate treatment for a retention
time as low as eight (8) hours.
Computer modelling was conducted to evaluate the performance
of the Republic POTW given the designed organic and solids loads
at several different total flows, including a total flow of
1.46 mgd. The 1.46 mgd modelled flow consisted of 0.8 mgd con-
tributing organic and solid "loads per designed rates and 0.66 mgd
contributing zero organic and solids loads. The modelling
results indicate that all NPDES effluent criteria would be met
satisfactorily with modification to the POTW's operating proce-
dure by reducing the aerator retention time, to sixteen (16)
hours. This modification can be done without capital
improvements.
The Wastewater Facilities Plan for Green County (1984)
projects a year 2025 population of 13,776. Based on this projec-
tion, the POTW will reach the design organic and solid loading
capacities sometime between the year 2005 and 2015, depending
whether the actual population loading contribution is high or
average. Actual Republic POTW data logs were evaluated for the
ten-month period between September 1986 and June 1987. Actual
11
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organic and solids loads during that time period averaged approx-
imately seventeen percent (17%) and forty-one percent (41%) below
the designed treatment organic and solids loads, respectively.
Question 3.
One alderman questioned the wording in the Proposed Plan
regarding the alternatives. Alternative III says the contami-
nants will be permanently, removed, and Alternative IV says the
contaminants will be permanently and irreversibly removed.
Alternative II does not say anything about whether the contami-
nants will be permanently or irreversibly removed. Why?
MDNR/EPA Response-:
This is simply an oversight in wording. The exact page in
the Proposed Plan reviewed by the alderman was not cited, but
there are other references in the feasibility study which have
wording to this effect. In Section 6.2 of the Feasibility Study
on page 6-20, the second paragraph states "Under Alternatives II,
III, and IV, contamination levels in the ground water in all
three systems would be irreversibly reduced to acceptable levels
with no remaining risks." On page 6-3, the paragraph above
section 6.4 states that "Alternatives II, III, and IV would all
be protective of human health and the environment by extracting
and treating the contaminated ground water. . . .the contaminants
would be permanently removed from the ground water." We believe
that Alternatives II, III, and IV will permanently and irrever-
sibly remove contaminants from the ground water equally,
regardless of the differences in text wording of the Proposed
Plan. Any omissions in the wording of Alternative II were
unintentional. •.
Question 4.
Several residents wanted the cleanest water possible dis-
charged to the POTW. They wanted metals removal, air stripping,
and carbon adsorption of the extracted water prior to discharging
it to the POTW.
MDNR/EPA Response;
A POTW is designed to process a city's domestic and indus-
trial waste to produce an acceptable effluent. Its purpose is
not to handle the cleanest water possible. -Often times, indus-
trial waste requires pretreatment before discharge to the sewer.
Calculations indicate that Republic's POTW can reduce up to 200
micrograms per liter (ug/1) TCE to meet its NPDES discharge limit
of 2 ug/1. Pretreatment standards for the SSC discharge were
established at 200 gallons per minute (gpm) and 200 ug/1.
12
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SSC discharged treated water from the air strippers
periodically during the remedial investigation. SSC has sampled
the POTW effluent during these discharges, and the POTW limit of
2 ug/1 was only exceeded once. An evaluation of this excursion
did not link it to the treated water discharged from the air
strippers. Additionally, City Well Number 1 has been pumped and
discharged almost continuously to the sewer without treatment
since the levels of TCE have been consistently below 200 ug/1.
SSC sampled the POTW influent and effluent twice a month, and the
NPDES permit limit has not been exceeded. Thus, Alternative II
does not require carbon adsorption.
A metals removal step is not required for Alternative II due
to two reasons: 1) the Republic POTW's NPDES permit does not
include limits on the metals in question; and, 2) as explained in
question Number 1, dilution in the sewer, POTW metals removal,
and 80 percent pumping from the deep aquifer will produce a POTW
effluent which is anticipated to meet applicable regulations or
•relevant pretreatment standards. MDNR's water pollution control
program concurred with these statements.
The suggestion was made to combine elements of Alternatives
II and III, in which there would be metals removal, air stripping
and carbon adsorption of the extracted water prior to discharging
it to the POTW. As the discussion above shows, such pretreat-
ments are unnecessary for discharge into the POTW.
Further, it is not cost effective to provide such
treatments, basically to the standard for discharge into Schuyler
Creek under a NPDES permit, and in addition pay the substantial
amounts in user fees that would be required for use of the POTW.
In other words, Alternatives II and III are mutually exclusive,
and a combination of the two would result in duplicative
treatments and costs for the remediation.
Question 5. •
A question was asked about the frequency of monitoring and
how long it takes to get sampling results back. What if the TCE
concentration exceeds 200 ug/1 and it takes a while before the
TCE exceedance is discovered? What will happen to the POTW? -
MDNR/EPA Response;
The POTW has been sampled twice a month during the RI/FS.
A monitoring frequency has not yet been established for RD/RA;
however, the feasibility study proposes a frequency of once a
week. The normal time required to get volatile organic sample
results back from the laboratory ranges from two to three weeks.
It is possible that a TCE exceedance may not be detected for
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three weeks. However, wastewater., treatment plants have a large
buffering capacity to protect the treatment facility and the.
environment from unexpected shock loads of harmful materials.
.The NPDES permit requires that the TCE effluent
concentration achieve a monthly average of 2 ug/i and that it be
measured once every six months. SSC is already sampling the POTW
twice a month.
A review of the treated effluent from Stripper Tower 2
(pages. 4-122 of the RI report) shows that from September 21, 198.7
to December 23, 1988, the TCE level in the treated effluent prior.
to discharge to the POTW ranged from nondetect (2.0 ug/1) to
26 ug/1. Prior to September 21, 1987, there were two results
which exceeded 200 ppb. These occurred during startup of the
stripping tower system when the process was not optimized. The
air strippers have proven that they can consistently achieve low
TCE concentrations well below 200 ppb. Additionally, as the
remediation progresses, the levels of VOCs in the ground water
will continually decrease so the air stripper effluent will have
even lower levels of VOCs.
If the efficiency of the air stripping towers was not known,
more frequent monitoring of the effluent would be warranted.
However, considerable data shows that the air strippers are
performing at the level for which they were designed. Unless
there are significant design changes, which adversely affect the
stripping efficiency of the towers, sampling for the stripper
tower effluent will not be required more frequently than twice a
month.
There will be four new unconsolidated/fractured shallow
bedrock extraction wells constructed in the plume along Main
Street to Highway 60. The feasibility study proposes that two of
these wells may be discharged directly to the sewer system, if
the level of TCE is below 200 ug/1. These new discharge points
will require frequent monitoring, at first, until the Agencies
are satisfied that the levels consistently remain below 200 ug/1.
Question 6.
One alderman commented that Alternative III, which features
metals removal, will produce a metals sludge residual requiring
offsite disposal at an approved waste disposal facility. This
would be giving a part of Republic's problem to someone else.
The alderman commented that Republic should deal with its own
waste.
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MDNR7EPA Response;
We agree with this comment. Alternative III is not as
desirable a remedy; because, it produces the metals residual,
whereas Alternative II will produce no .residuals. Also,
Alternatives III and IV will both produce a spent carbon residual
which will need to be regenerated (heated at high temperatures)
to destroy the volatile organics removed by the carbon.
Question 7.
A question was asked about the ground water movement. Will
the contaminated plume enter a large underground cavern and
disappear?
MDNR/EPA Response:
The immediate site area is not highly karst. Extensive
geophysical surveys (a very low frequency survey and a shallow
seismic survey) were conducted to determine underground features.
A bedrock low was identified along Main Street, which is
providing a pathway for the TCE migration along Main Street
toward Highway 60. There is a normal amount of fracturing in the
upper part of the shallow bedrock system where it meets the
unconsolidated system, but there were no large fractures or
caverns identified through which the contaminated plumes will
disappear.
Question 8.
Several residents asked how much testing has been done to
determine the spread of contaminants to surrounding surface
areas.
MDNR/EPA Response;
A total of 15 pre-RI background surface soil samples was
collected by MDNR and the EPA to help characterize the soil
chemistry near and around the site. Samples were analyzed for
volatile organic compounds or TCE. With the exception of two
MDNR samples, the laboratory analytical data showed that VOCs
were not present in any offsite soil samples. MDNR analytical
reports indicate the only compound detected in the two MDNR
samples was TCE at 2.0 and 270 ug/kg in samples collected from a
garden area at 230 S. Main Street and the ditch on the east side
of Main Street at 230 S. Main Street, respectively. The
2.0 ug/kg TCE detected in the garden soil sample is below levels
of concern, and the 270 ug/kg TCE reported for the ditch sample -
was determined by MDNR to be a laboratory error.
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During the,Rl, a total of 54 offsite subsurface (greater
than 12 inches in depth) soil samples were collected from soil
borings during shallow unconsolidated zone monitoring well
construction. TCE concentrations were consistently less than
10 ug/kg at depths less than approximately 15 feet below the land
surface. The maximum TCE concentrations, up to 340 ug/kg, are
found at depths greater than 15 feet below land surface and are
primarily confined to the two to three foot zone above the top of
the bedrock. The VOCs in ground water are the source for the
VOC's found in the soils.
Question 9.
One resident ^sked about the health risks to citizens living
in a three-block .adius due, to the movement of shallow ground
water into basements or the movement of surface water on lawns,
gardens, and ditches.
MDNR/EPA Response:
Solid State Circuits, at the request of MDNR and EPA,
sampled air in a storm cellar, a partial basement, a crawl space,
and a full basement along Main Street south of the site. The
results of these air samples showed that the volatile organic
compounds have not entered these below grade structures. Surface
water runoff from the site should not be a problem, since no
surface soil contamination remains onsite. As discussed in the *
previous question, no offsite surface soil contamination was
found. Additionally, no surface water contamination was discov-
ered. Robert's Spring in Shuyler Creek was sampled. No constit-
uents related to the SSC site were found in surface water
samples.
Question 10.
One alderman questioned if it was our intent to increase
pumping to 1,000 gpm, if any POTW study had taken that into
consideration and will we increase the rate without the City's
knowledge?
MDNR/EPA Response:
The pumping rate will not be increased to 1,000 .gpm. This
pumping rate was evaluated earlier in the feasibility study
process. There were some alternatives which evaluated using
existing wells REM-1 and CW-1 and a new deep bedrock well. These
wells would be pumped on an expedited schedule so that all con-
tamination in the aquifer would be removed in 5 to 10 years. The
total required flow rate for all wells would be approximately
1,000 gpm. This combined pumping rate was selected because it
would not adversely affect water levels in the City of Republic's
municipal wells. These expedited alternatives were rejected
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because the adequate city water supply did not justify the cost
of an expedited cleanup. Additionally, there were no increased
health benefits from an expedited cleanup because no one is
presently exposed to contaminated ground water either through
direct contact or ingestion.
Question 11.
Several residents asked if we could guarantee rural wells
around Republic free from TCE from this site if they were at
least 300 feet deep. Do rural residents need to have their wells
tested, and who is going to pay for the testing?
MDN.R/EPA Response;
There are no guarantees. Based on what is presently known
about the extent of contamination, the rural wells should not be
affected by the site. The plumes in the deep bedrcck and the
shallow bedrock aquifers extend no further south f_om the site
than City Well Number 1, and the unconsolidated plume is confined
to a narrow band along Main Street, which extends south to
Highway 60. Republic's other municipal'wells have been sampled
on a monthly basis, and no contamination has been detected in
these wells. The Missouri Department of Health has sample
selected rural wells within one and a- half mile south and east of
the site, and no contamination has been detected. We do not feel
there is a need for rural residents to have their wells sampled.
Rural residents may want to have their wells sampled for their
own reassurance, but this expense must be borne by the well
owner.
Question 12.
One alderman asked if this problem reaches well Number 2 in
13 years, could we expect SSC to build the city a new well. Why
should the city keep closing wells with no replacements?
MDNR/EPA Response;
Ground water modelling has been used to show that onsite
pumpage will control the spread of contamination to prevent
Municipal Well Number 2 from becoming contaminated. The proposed
rate of 150 gpm is more than adequate to control the plume. It
is only in the absence of onsite pumping that the plume will
migrate. The selected remedy will utilize onsite pumping.to draw
the contaminants back toward the site so they can be withdrawn
with the extraction wells and treated by air stripping. The
contaminants will be removed from the ground water, and in time
the levels will be reduced to safe drinking water levels.
Municipal Well Number 1 can then be placed back in service if
this is what the City of Republic wants to do.
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Question 13.
One citizen asked, "What proof do we have that the air
stripping process is a safe process? How do we know that we
won't be exposed to airborne TCE instead of exposure through the
water supply? Will there be an ambient air monitoring program?"
MDNP./EPA Response;
The Industrial Source Complex Long Term (ISCLT) model was
used to estimate probable annual emission rates from the air
stripping tower operation. The ISCLT model is an air dispersion
model that solves for the distribution of chemicals in the air.
The model uses historic meteorological data for the area of
interest and site specific chemical data to estimate potential
contaminant concentrations at predicted locations of maximum
effect. In January 1988, a three-week aquifer test was 'conducted
at the site in which the contaminated ground water was pumped
from the bedrock units with onsite wells and treated through the .
air stripper system. Chemical data was collected from the
stripper tower influent during the aquifer test, and the removal
efficiency.of the stripper towers was calculated. Based on
stripper tower VOC removal efficiencies calculated during the
aquifer test, a mass emission rate for each compound was calcu-
lated. The meteorological data from Springfield, Missouri and
emission rates calculated from the onsite aquifer test were used
in the ISCLT modeling effort. The model evaluated two tower
heights and three different flow rates. The simulation runs for
the lowest tower height and the highest flow rate (150 gpm)
represented the highest emission rates. The highest rates were
used to determine health risks associated with the stripper tower
emissions. The noncarcinogenic risks from inhalation exposure
were 0.0782, 0.2284, and 0.3997 for an adult, child, and infant,
respectively. An acceptable noncarcinogenic risk is 1.0 or less.
The carcinogenic risks were 6.5 x 10" , 5.7 x 1.0,
and 1.6 x 10 for an adult, child, and infant,.respectively.
The acceptable carcinogenic risk range is from 1 x 10 to
1 x 10 . Tne health risk calculations indicate that the
long-term exposure to stripper tower emissions does not pose
unacceptable public health risks.
The need for an ambient air monitoring program will be
evaluated during remedial design.
Question 14.
One citizen asked, that if this situation is not handled
perfectly, who will pay 20 years down the road when law suits for
cancerous situations occur for citizens of Republic?
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MDNR/EPA RESPONSE;
Presently, there is no unacceptable health-based exposure to
the public. During the remedial action, it is anticipated there
will be no unacceptable, health-based exposure to the public.
These statements are supported by extensive sampling in the past
and planned sampling in the future.
Also, the responsible parties will never be relieved of
their legal liability associated with the release of the
contaminants.
Question 15.
Two people asked how safe is the drinking water at the
present time. What steps are taken to ensure the ground water
contamination does not seep into the water pipes which service
the homes? How secure is the water system? How old are the
water pipes?
MDNR/EPA Response:
The MDNR has sampled the other three municipal wells (2, 3,
and 4) on a monthly basis. To date, we have detected no contami-
nation in these well samples. In October 1988, we did detect
1,1,1-trichloroethane (TCA) at 5.1 ug/1 in a sample taken from
Municipal Well No. 2; however, the contaminant has not been
detected since or prior to the October 1988 sample. The minimum
quantity of 1,1,1-TCA, which can be detected with the analytical
method is 5.0 ug/1. The detected amount was only 0.1 ug/1 above
the minimum detection limit. Since subsequent sampling has been
nondetect for 1,1,1-TCA, we believe that the one-time occurrence
was an anomaly which sometimes occurs in data analysis. We have
also sampled the distribution point prior to the water going to
homes and have found no contamination. The water supply is safe
at the present time. No one is in direct contact with the City's
water and no one is ingesting contaminated ground water.
We do not have specific information about the age of the
water lines. The state is receives design information when new
water lines are added to the distribution system; however, the
lines will be periodically replaced by the City of Republic. The
best source of information about the age of water pipes in your
area would be the City of Republic.
In general, water lines are under pressure. Water will seep
out, but no water will enter the lines because of the pressure.
The testing required by the state for community water systems
will indicate a problem. One of the tests required is for
coliform bacteria. If water is seeping into the lines, the
bacteria count will exceed acceptable standards.
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Question 16.
One person asked if the Blue Goose or some other purifier
machine was considered. He wondered why the agencies didn't try
the Blue Goose when it was near Verona, Missouri.
MDNR/EPA Response;
In the initial screening for the feasibility study, we did
evaluate thermal destruction. The process options considered
were liquid.injection, rotary kiln, fluidized bed, multiple
hearth, onsite mobile incineration (like the Blue. Goose), and
offsite RCRA incineration. All of the process options were-
rejected because they were not feasible for dilute ground water
contaminants.
Question 17.
One person asked if we had considered pumping clean water
down through satellite wells and up through well Number 1 to
dilute the contaminated plume in an attempt to reverse the
contamination direction.
MDNR/EPA Response;
This sounds similar to Alternative IV in which the contami-
nated ground water will be extracted through City Well Number 1
and onsite well REM-1 and reinjected into the deep bedrock
aquifer via reinjection wells. The water table will be lowered
around the extraction wells, and the reinjected water will raise
the water table around the reinjection wells. This will create a
water gradient toward the extraction wells since ground water
flows downhill from higher water tables to lower water tables.
The contaminants will flow with the ground water toward the
extraction wells. The extracted water will be air stripped and
then undergo carbon adsorption so that the injected water will
meet the standards for ground water quality. No contaminants
will be reinjected back into the aquifer. This alternative, will
accelerate the cleanup because the extraction wells alone will
reduce the contaminant migration, and the artificial ground water
gradient will further reverse the contaminant direction toward
them.
Question 18.
A person wanted to know how water is scrubbed.
MDNR/EPA Response; -
Scrubbing could refer to either air stripping or carbon
adsorption. A well documented and established technology for VOC
removal is countercurrent packed tower (CCPT) air stripping. YOG
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contaminated water is passed through a tower packed with a porous
medium and brought in contact with air forced through the tower
in a direction opposite to the water flow. A typical air-to-
water ratio for VOC removal is 100:1. The porous medium causes
an intimate contact between air and liquid, resulting in the VOC
being "stripped" from the water and exhausted into the
atmosphere. Packing media materials are made of glass, ceramic,
or plastic of various geometrical shapes. CCPT air strippers can
remove greater than 99 percent of VOC in solutions and are most
cost effective when treating large volumes of water.
Carbon adsorption is a conventional treatment process that
will remove a broad spectrum of organic compounds from dilute
aqueous solutions. The process uses granular activated carbon
which attracts the contaminants. As the contaminated ground
water passes through the carbon unit, the contaminant will leave
the water and adhere to the carbon through a combination of
physical and chemical attractions. The contaminant laden carbon
will eventually become saturated, or lose its ability to attract
additional contaminants, and it must be removed and disposed or
regenerated for future use. Regeneration is accomplished by
heating the spent carbon at high temperatures to destroy the
contaminants.
Question 19.
One citizen asked why this has taken so long when MDNR was
asked to take action in 1970, 1971, and 1972, when Solid State
Circuits was dumping their wastes in a pond in Christian County
and on the farm roads.
MDNR/EPA Response;
The contamination in Republic's drinking water supply was
not discovered, until early 1983. In June 1982, EPA funded random
sampling of municipal water supplies to analyze for synthetic
organic compounds. After the contamination was discovered, MDNR
took actions to identify the source and both MDNR and EPA initi-
ated removal actions to remove the soil as a continuing source of
contamination.
We have followed up on leads provided to us by citizens in
the public meeting. . The pond in Christian County has already
been investigated. The location is southwest of Haseltine Road
and Highway FF on the Christian County Line. SSC hauled
wastew.ater to two lined ponds on the former Joe Carroll property.
In July 1972, the Springfield Regional Office received a report
that the lagoons were leaking. Samples taken from nearby wells
and springs in July 1972 showed no contamination. The MDNR has
been told that the water, sludge, and liners from the lagoon and
the contaminated soils were hauled off to an approved disposal
site; however, no documentation exists to verify this. A few
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years ago, the department sampled nearby wells and the surface
soil in the lagoons and detected no contamination. MDNR plans to
return to the site and take subsurface samples in the lagoons to
verify that no contamination has been left in place.
The farm roads may not have been previously investigated.
An official from the MDNR's Springfield Regional office will be
contacting the person who asked this question during the public
meeting to have her locate the farm roads on a map. We will then
be investigating these locations.
It is important to note that both activities do not affect
the investigation results or decision process related to this
Record of Decision. Any actions r-equired for the pond in
Christian County or the farm roads will be conducted independent .
of the activities selected in this ROD.
Question 20..
Several citizens stated that Solid State Circuits should
have to pay a higher rate to use the POTW than the citizens of
Republic. Currently, the residents pay $2.05 per 1000 gallons
and SSC has negotiated a rate of $1.25 per 1000 gallons.
MDNR/EPA Response:
MDNR and EPA are not parties to this agreement between the
City of Republic and Solid State Circuits. It is our understand-
ing that the 1986 agreement allows SSC to discharge "effluent from
the site to the sewer system was recently amended by an unanimous
vote of the City Board of Aldermen on June 12, -1989. The reduced
rate of $1.25 per 1000 gallons was included in the second supple-
mental agreement. As stated in the response to Question 2, the
SSC discharge is very unlike the sewer discharge coming from
domestic and commercial sources.
Question 21.
One person asked about the integrity of the sewer lines. He
commented that we may spread the VOC contamination all over town
because the lines leak.
MDNR/EPA Response;
This is a concern of both Agencies. The adequacy of the
lines to convey the treated effluent for the duration of the
remedial action is uncertain. New sewer lines with larger capac-
ities exist within 2,600 feet of the site. Moving the location
where the effluent enters the sewers may alleviate some of this
uncertainty. This will be evaluated during remedial design.
Additionally, we have concerns about the capacity of the sewer
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lines during heavy rainstorms. Flow depth monitoring equipment
will be installed in the discharge sewer manholes so that the
site discharge will be halted during periods of high sewer flow.
Question 22.
One person asked if we had identified any private wells in
the vicinity of the site, and if they were contaminated.
MDNR/EPA Response:
Private well surveys were conducted in July 1987 and May
1988. A total of 155 individual properties were included in the
survey. The survey-area included a 1,000 foot radius centered
around the site. The initially proposed survey area was expanded
somewhat, based on street and block definition. The survey area
was later expanded to include all property immediately adjacent
to Main Street south to Highway 60. Page 2-89, Figure .2.24, of
the RI report is a map which shows the private well survey area.
Only one existing private well was identified as currently
accessible. The well is located at 129 South Main Street and is
approximately 20 feet deep. Page 3-126, Figure 3-52, of the RI
shows the location of the private well identified in the private
well survey. The property owner reported that the well was no
longer used. The well was sampled on March 7, 1988, and the TCE
concentration was 2.9 ug/1. Many respondents reported that they
used to have a well on their property, but the wells have since
been filled in or covered by home expansions or driveways. All
properties included in the survey are serviced by the City of
Republic's water and sewer system.
Question 23.
There were several questions asked about the levels of TCE
remaining in onsite soil after removal actions. One person said
he had read in reports that 4,900 ug/kg TCE still remained at the
excavated basement location.
MDNR/EPA Response:
This is true. It was not possible to excavate the contami-
nated soil completely due to site constraints of excavating to
bedrock and encountering the unconsolldated/fractured shallow
bedrock aquifer. The greatest soil contamination has been found
at the subsurface close to the bedrock. We believe that the
contaminated ground water is the source of the soil contamination
at the lower depths, since, ground water VOC concentrations are
five or more times greater than the soil VOC concentrations.
At other sites in Missouri, the Department of Health has
established a safe soil level of 70 milligrams/liter, or 70,000
ug/1 for TCE. This means that at levels below the safe soil
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level, a person can live on'j the site, his children can sit on the
surface soil and eat the soil through their normal play
activities. The contamination remaining onsite is well below the
safe soil level, and it does not appear at the surface.
Additionally, the Solid State Circuits site was placed on the
Registry of Confirmed Abandoned or Uncontrolled Hazardous Waste
Disposal Sites in Missouri on February 22, 1985. The .department
will be approving changes in use of the property as long as it .
remains on the Registry. Any change, which adversely impacts the
remediation, will not be approved.
Question 24.
A question was asked about the reliability of data generated
by Solid State Circuits, Inc.
MDNR/EPA Response:
As stated in the public meeting, the agencies have no reason
to distrust SSC's data. We have approved their sampling plans
and procedures, have reviewed quality assurance/quality control
information for the laboratories they have selected for
analytical services, and have observed their sampling procedures
personally. Additionally, we have randomly taken split samples
and submitted them to our laboratories for independent analysis.
We have given SSC audit, or control samples, with concentrations
known only by the agencies to see how well SSC's laboratory
achieved the known values. The splits and audit, sample results
have compared favorably to agency results. We did .not detect any
problems with the data generated by SSC. Additionally, for the
RI/FS, SSC personnel did not perform the sampling and analysis
themselves. Rather, SSC engaged the professional services of
firms with expertise and experience in the field of ground water
remediation.
Question 25.
One person asked about a Total Organic Carbon (TOC) NPDES
limit for the POTW.
MDNR/EPA Response:
This method measures all.of the carbon in a sample. The
usefulness of the carbon measurement is in assessing the
potential oxygen-demanding load of organic material on a
receiving stream. This statement applies whether the carbon
measurement is made on a sewage plant effluent, on industrial
waste, or on water taken directly from the stream. The TOC test
does not differentiate between toxic and nontoxic forms of
carbon. The state uses TOC as an indicator parameter and does
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not usually have a specific TOG limit in the NPDES permit. The
NPDES permit for the POTW at Dry Branch does not have a TOG final
effluent limitation.
Question 26.
One person asked if we had looked at land applying the
treated effluent coming out of the air strippers. One beneficial
use might be to provide pipelines to farms so the water could be
used for irrigation.
MDNR/EPA Response:
This is a valid comment. According to 10 CSR 20-7.015,
Effluent Regulations, discharges to losing streams shall be
permitted only after other alternatives including land
application, discharge to a gaining stream and connection to a
regional wastewater treatment facility have been evaluated and
determined to be unacceptable for environmental and/or economic
reasons. We have not selected Alternative III as the remedy for
the site, so a detailed analysis of land application has not been
conducted. On the surface, it appears that land application
would be more expensive than Alternative II since pipelines to
farms would need to be constructed. The additional treatment
technologies of metals removal and carbon- adsorption may be
needed before the treated water could be land applied. This
would greatly increase the cost.
Question 27.
The United States Department of the Interior (DOI) asked
questions about Alternative III which discharges the treated
water into Shuyler Creek. The creek (also known as Skeggs
Branch) flows southeasterly into the Wilson's Creek National
Battlefield where it merges with Wilson Creek. It is the most
significant tributary stream within the boundaries of the
Battlefield. USDOI was concerned about how Alternative III would
affect the water quality of Shuyler Creek. Among their concerns:
a) The proposed discharge into Shuyler Creek would nearly
double the low water flow of this stream over an
extended period of time. How would this increased flow
affect the creek's aquatic life?
b). How would the array of chemical constituents (such as
alkalinity, pH, major cations and ions) in the treated
water differ from the current chemical constituents of.
Shuyler Creek? How would aquatic life be affected?
c) What would the temperature of the treated water be and
how would this affect aquatic life?
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d) Hundreds of thousands of visitors from all-over the
world visit Wilson's Creek National Battlefield. Based
on regional growth and Battlefield development, this
visitation is expected to rise substantially in the
future. Many of our visitors come into close and/or
direct contact with Shuyler Creek. The park's Tour Road
crosses the creek and a major park trail fords the
creek. What are the potential environmental health
hazards associated with any residue of known toxins in
the water?
MDNR/EPA Response:
Shuyler Creek is not classified in Missouri Water Quality
Standards. This means that it does not contain flow or pools in
drought conditions, according to surveys. This is consistent
with its "losing" stream designation; that is, much of its flow
is lost to ground water. However, we understand the stream flows
part of the time and supports some aquatic life. Therefore, we
require protection against acute toxicity. We do have aquatic
life protection numeric limits for a number of constituents.
These would also serve as discharge limits, since no dilution
flow would be available.
Increased flow from a discharge which meets the acute
toxicity standards for aquatic life protection could provide
additional habitat and even have a beneficial effect on aquatic
life in Shuyler Creek. No impact would be expected on Wilson
Creek.
Major irons and pH in the discharge would be required to
meet the range of the water quality standard's aquatic life
criteria, so the discharge would not be substantially different
from natural conditions.
Effluent temperature would be limited per the water quality
standards no more than a 5°F change from ambient temperatures and
no more than 90°F maximum.
Organic contaminant reduction in the treatment process will
be required to achieve pertinent health-based standards, which
are the drinking water supply and ground water criteria.
Question 28.
One resident stated in a phone call to MDNR that he had
grave concerns about the release of the treated water to Shuyler
Creek. He was concerned that the treated release would affect
his private drinking well, since Shuyler Creek is a losing stream
and the flow goes underground. He remembered that when the old
POTW collapsed, releasing raw sewage, private wells were
contaminated.
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MDNR/EPA Response;
The release of treated water to Shuyler Creek will require
an NPDES permit for the discharge. The permit parameters and
limits will be established by using state water quality standards
for aquatic life protection. Since Shuyler Creek loses its water
to ground water, the discharge will meet ground water standards,
in case the discharge does travel underground to a private well.
C. Public Participation Process
Question 1.
Several residents requested an extension of the review
period.
MDNR/EPA Response;
First, a 22-day public comment period was established from
August 14 to September 5, 1989. Ten days had elapsed since the
beginning of the public comment period on August 14 until the
date of the public meeting, August 24. A full twelve days of
review time was still available from August 24 until September 5,
1989. Additionally, the National Contingency Plan establishes a
21-day public comment period. However, in response to the
request, the state and EPA did extend the public comment period
an ad--.tional nine days until September 14, 1989.
D. Costs/Funding Issues
Question 1.
Several people asked who is going to pay for the cleanup.
MDNR/EPA Response:
The Superfund Law stipulates that, whenever possible,
Potentially Responsible Parties (PRPs) pay for remedial actions
at a Superfund site. PRPs can conduct the remedial action or EPA
can take action following the cleanup to recover monies for
Superfund.
After the Record of Decision (the remedy selection document)
is signed, MDNR and EPA will ask Solid State Circuits, Inc. (SSC)
to undertake the design and implementation of the selected
remedy. If SSC agrees, MDNR and EPA will enter into a consent
decree with SSC similar to the agreement for the remedial
investigation/feasibility study.
If SSC decides not to conduct the cleanup, then the cleanup
will be funded with federal Superfund money, with the state
paying a 10% cost share for the remedial action. The state will
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assume responsibility for'all future operation and maintenance
(O&M) costs for the. expected life of the remedial action. Both
the state and EPA will seek to recover their costs of cleanup and
O&M from SSC and other PRPs.
Question 2.
An alderman asked, if Alternative .II is selected and the
POTW balance is upset, who will pay for a new POTW.
MDNR/EPA Response;
Regardless of the agreement which exists between SSC and the
City of Republic, the MDNR and EPA will not release SSC from any
legal liability associated with implementing the selected remedy.
Question 3.
One person asked if the "push" for Alternative II wasn't
simply a financially effective move by SSC.
MDNR/EPA Response;
Alternative II is the selected cleanup remedy for the site
because it represented the best balance, when compared against
the nine evaluation criteria, .ne of which is cost effectiveness.
The National Contingency Plan (NCP) specifies the nine evaluation
criteria in the decision process for remedial actions at
Superfund sites. Cost is also important to the state and to EPA,
since it may be necessary to fund the remedy with Federal
Superfund monies, with the state providing a 10 percent cost
share, in the event that responsible parties elect not to
implement the remedy. MDNR and EPA will not compromise on the
effectiveness of an alternative to meet the cost-effectiveness
criterion. However, among those alternatives considered equally
effective, MDNK and EPA select the least costly. This preserves
monies for other Superfund sites.
4.0 COMMUNITY RELATIONS ACTIVITIES AT SOLID STATE CIRCUITS SITE
Community relations activities conducted at the Solid State
Circuits site to date have included:
MDNR issued a press release announcing that they would
be assuming responsibility for the remedial
investigation/feasibility study (RI/FS) following the
completion of the removal actions (October 8, 1985);
MDNR conducted phone and personal interviews with local
officials .and interested residents to identify community
concerns (February through April 1986) ;
28
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MDNR prepared community relations plan (October 8,1986);
MDNR prepared and distributed a fact sheet on health
effects of site contaminants and details about the "
cleanup to date (September 1986);
MDNR issued a news release announcing a public meeting
on May 4, 1987 to discuss the steps to be taken by the
Department and Solid State Circuits during the RI/FS
(April 21, 1987) ;
MDNR prepared and distributed a fact sheet informing the
public about the ground water investigation in Republic
(May 1987) ;
MDNR issued a news release announcing that the RI/FS
investigation had begun in Republic (June 17, 1987);
MDNR established an information repository at the
Greene County Branch-Republic Branch (June 24, 1987);
MDNR prepared and distributed fact sheets summarizing
the RI/FS conclusions and the proposed plan
(August 1989);
MDNR released the administrative record, which included
the RI/FS, and the Proposed Plan for.public review and
comment (August 14, 1989);
MDNR and EPA held a public meeting at the Republic High
School cafeteria in Republic to describe the RI/FS and
the proposed plan and to respond to citizens' questions.
Approximately 100 people attended, including citizens,
elected officials, and technical representatives of the
PRPs (August 24, 1989). A transcript of this meeting
will be placed in the administrative record file at the
Greene County Library - Republic Branch; and,
MDNR and EPA allowed one extension to the public comment
period. The comment period began August 14 and was
extended to September 14, 1989.
29
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NOTE: This inserted portion includes revisions to the Standards
which-became dKC^tlVtet^ril-.tS^lSfl?./ Most of the changes are in
Table A, which is reprinted in its entirety.
Table A—Criteria for Designated Uses
I = Protection of Aquatic Life
II = Drinking Water Supply
III = Irrigation
IV = Livestock. Wildlife Watering
V - Whole-Body-Contact Recreation
VI = Ground Water'see subsection ''><>.\n
VII = Ground Water isee subsection i5nBn
Pollutant (ug/I)
II
III
IV
VI
VII
Chlorine*
Cvanide"
10<2)
5
* measured as total residual chlorine
warm-water and cool-water fisheries—10 ug 1: cold-water fisheries—2 ug. 1
"measured as cvanide amenable to chlorination
Pollutant (mg/1)
Chloride
Sulfate
Fluonde
Nitrate-N
Dissolved Oxygen (minimum)"
Ammonia-N
I
•
*
5<6)
* **
II III IV V
250
250
2.2 4
10
VI VII
•) o •; •••
10 10
* *«
* see subsection [4)iL)
" warm-water and cool-water-fisheries—5 mg 1: cold-water fisheries—6 rag;
"* see Table B
Pollutant 1/100 ml)
II
III
IV
VI
VII
Fecal Coliform Bacteria
Pollutant (: F)
Temperature
warm-water maximum
cool-water maximum
cold-water maximum
warm-water change
•.:^ol-water change
•.old-water change
Pollutant lug/1)
•percent saturation)
Total Dissolved Gases
I II
90
34
68
5
5
2
I II
110%
III IV V VI VII
III IV V VI VII
Roy D. Blunt
Stcrtury of SUtt
(5/89)
CODE OF STATE REGULATIONS
-------
The toxic form of metals shall be determined by the following methods: For aquatic life protection- 'column I and aquatic life numbers in
column VI)—Iron and Copper—Dissolved; Mercury—Total Recoverable
Other metals—
As determined by acid soluble analysis when that method becomes approved by the Environmental Protection Agency. Until that method
is approved, both the dissolved and total recoverable analysis should be performed.
Drinking water supply-
Total metals in column II and for drinking water supply limits in columns VI and VII.
Other uses-
Total-metals for uses designated in columns III and IV.
" Hardness is defined as the total concentration of magnesium and calcium ions expressed as calcium carbonate. For purposes of this rule.
•/. vv.li be determined by the ar.thmetic average of .1 representative number of samples from :he water bodv ;n question jr from ,i iirniiar
p.trarbv water bodv.
Pollutant
IUg/1)
11 III IV
VI
VII
MeluU
\r--nii
chrnmc IWXKIEV maximum-
i-,,id-wdu?r fishery
lier.enu wdnri-wac*j n^ner1. . '
acuc* tnxicuy maximum
ir.ic '.oxu':;% rr.a.ximum
wd *drm-*drer P.ahery
'.oxicity maxirnum
: • j t j • •* d te r n 5 r. t rv ^ e r. e r a i
runic toxicity maximum
Id *aier fishery
-*'at*r fisherv
trrai warm *'HUJ iiherv
H a rd n e?* ?*_*_* • m g/11
H d rj^n *?!*_!*"' nnt_' Ij
limited •
,icut« tu
general •*tum-'*atrf diner.1
limited wtirm »at*r fisher.1
warm-wau* r
CODE OF STATE REGULATIONS
(5/89) Roy 0. Blunt
Secntirr ot S:att
-------
Lead
..Tronic luxjoty maximum.
ai! c i .1 a a i ft fJ * Liters
acute '.oxicitv maximum
.50
Hardnefla**(mg/ll
l.'5 IJo-^OO -'JOO
Hardnc»8**'rng/lj
i:nrum<: Cnxicity maximum.
ail cuisaifit-d waters /J j,' _'ij
same is existing :r*,:tr.cni
t'jie tuxicitv maximum
Hardnestt "img/ h
H ardne w**1 mg/1)
Hardness**' rnx/1)
aeieniu
S:ivtfr
cnromc toxicity maximum
Jakes
coiU wat«?r r'.ahtT'.
genera] *Hrm-*at£T dshery
umiwo warm-'*at*r n^her>
dcut« toxicity majtimum
lakes
cold-'*at*r fishery
ijencrai warm-wala daherv
limited warm-wd«r risherv •
to
chrnnic 'uxicity maximum.
Hardnes9**'mg/l)
i water fisher.'.
i warm-w'ater tiahuy >*i'j
limited warm-wat«r fianer/ 4-_5
chronic '.oxicity maximum:
ail ciadtiified waters
H_ardn *?
icui* IOXJCHV mai.mum
all classtrieO waters
chronic toncily maximum.
!.oid water rlshery
lakes
general warm-water nshery
!imit*<3 wdrm-'*dn?r fishery
acute'. miixisum
f;uid water fisher."
lakes
general -^a.-m water rishery
'.i.T.u*-! warm-^-aujr naherv
Hardneag*"fmit/l)
-.1J5 !J5— Jt'XD ->JOO
.*^'i -J40 310
105 150 190
^45 ,U5 440
1 .»io 1505 !9'JO
1 : tf»J i 6*50
chronic toxicity maximum.
cold-water fishery
lakes
ijeneraJ warm-water fishery
limiwd v.arm-water narn?ry
The toxic form of metals shall be determined by the following methods.
• For aquatic life protection (column I and aquatic life numbers in column VI)—
Iron and copper dissolved; mercury—total recoverable
** Hardness is defined as the total concentration of magnesium and calcium ions expressed as calcium-carbonate. For purpose:
of this rule, it will be determined by the arithmetic average of a representative number of samples from the water oody
in Question or from a similar nearby water body.
Otner metals—
As determined by acid soluble analysis when that method becomes approved by the Environmental Protection Agency. L'ntil
that method is approved, both the dissolved and total recoverable analysis should be performed.
Drinking water supply-
Total metals in column II and for drinking water supply limits in columns VI and VII
Other uses-
Total metals for uses designated in columns III and IV.
Roy 0. Blunt (5/89)
S*cr«ury ol Stilt
CODE Of STATE REGULATIONS
-------
Pollutant (ug/1)
II
III
IV
VI
VII
Organics ug/1
Acenaphthene
Acrolein
Bis-2-chlorbi:50propyl ether
2.4-dichlorophenol
Echylbenzene
Hexachiorocyclopentadiene
Uophorone
Nitrobenzene
J-chiorophenoi
Phenol
ihchloropropene
Fluyranthene
Paru-aichlurobenzene
1 >:her Dichiorobenzenes
l.l.l-tnchioroethane
/
320
.5
100
20
320
35
5200
30
1
1
•jT
40
75
400
200
20 20
320 320
35 35
7
i2'J
•J
:'200 jJ'jO
;M :f '
' ' i
;,,!'_. ;<'''}".
r][i(V2; . '(Vrjj
03" '-""
.001
.000'71 ->:i07!
J22
0022 v!*J22
.00046 00046
000 1 2 000 '. 2
.0000:3 OO1/ ! i
? 0
•).-
0.3
^ ™
14
23
39
CODE OF STATE REGULATIONS
(5/89) Roy 0 Blunt
-------
Persistent, Man-made Carcinogens* ug/1
Acrylonitrile
Hexachlorobenzene
Bis (2-chloroethy.il ether
Hexachloroethane
j.3'-dichlorobenzidine
Hexachlorobutadiene
n-nitrosodimethylamine
.053
.00072
.03
1.9
.01
.45
.0014
.053
.00072
.03 ' •
1.9
.01
.45
.UU14
.058
.00072
.03
;.9
Mi
45
0014
"• Many of these values are below-current detection limits: analyses will be determined by the latest.edition of Standard
Methods or the most'current analysis method approved by the Environmental Protection Agency.
"I'nus for dioxm = 'nanograms liter ing I) L iig 1 = 1000 ng. !
""* Toxic impurities may be present in technical-grade pentachlorophenoi: monitoring and discharge control will assure that smpur.::::es are
below toxic concentrations.
Pollutant (ug/1)
Volatile Organic Chemicals* ug/1
Chiorobenzene
Carbon Tetrachlonde
Halogenated methanes
1,2 dichloroethane
1,1-dichloroethylene
Trichloroethylene
Tetrachloroethylene
Benzene
Vinyl chloride
I II III IV V
20
5
0.19
5
"•
5
0,3
5
.)
VI
20
5
0.19
5
-
5
0.3
5
>
VII
•V|
Q
0.19
•5
-
5
0,3
5
-
"These cntena apply at water supply withdrawal points. Analyses will be determined by the latest edition of Standard Methods or the :
current analysis method approved by the Environmental Protection Agency.
TABLE G--LAKE CLASSIFICATIONS AND USE DESIGNATIONS
--Busch W.A. #M1 shouirl be #35
--Jackass Bend and Lawson City Lake are classified L3 instead of L2
TABLE H--STREAM CLASSIFICATIONS AND USE DESIGNATIONS
--An additional listing for the River des Peres includes 1 mile of
Class C stream, from Hwy. 267 to Morganford Road and an x in the LWW
and AQL columns .
--Squaw Cr. Ditch, 8 miles of Class P stream in Basin 11, is
deleted
Roy D Blunt (5/89)
Stcnllrr ot SUIl
CODE OF STATE REGULATIONS
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