NCD980840409_19941219_Charles Macon Lagoon & Drum_FRBCERCLA RD_Response to EPA Comments on Prefinal Design Documents-OCR

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REce,veo:
December 19, 1994
Ms. Giezelle S. Bennett
Remedial Project Manager
US Environmental Protection Agency
345 Courtland Street, NE
Atlanta, GA 30365
RE: Macon Dockery Site -Cordova, North Carolina
DEC 2 7 7994
SUPERFUNO S
Response to US EPA Comments on Prefinal Design Documents
Dear Ms. Bennett:
Transmitted herewith are seven copies of responses submitted on behalf of the Macon/Dockery Site
Group (MDSG) for US EPA's comments on the Prefinal Design documents. US EPA's comments were
received through correspondence dated December 7, 1994, from Gizelle Bennett to David Jones, the
MDSG Project Coordinator. Clarification of information provided in US EPA's transmittal letter was
obtained by MDSG representatives and documented in a letter dated December 9, 1994, from David
Jones to Giezelle Bennett. The responses transmitted herewith constitute the Group's compliance
with the December 19, 1994, deadline agreed upon with US EPA.
Also provided with this transmittal is the schedule referenced in the December 9, 1994,
correspondence. The following dates summarize the important milestones which indicate that the
source area ground water remedy can be integrated with the entire remedial action schedule without
jeopardizing the projected start-up deadline of December 1995.
System Demonstration and Optimization
Evaluation of System Feasibility/
Selection of Source Remedy
Develop Source Area System Design
Interim Report with 90% Design Submittal
Complete Design and Incorporate US EPA Comments
Submit Final Design for Source Areas
US EPA Design Approval
Full-Scale Construction
INC.
12/19/94 -4/30/95
1 /16/95 -2/14/95
2/14/95 -4/17/95
4/17/95
4/17 /95 -6/16/95
6/16/95
6/30/95
7 /3/95 -12/4/95
RMT, INC. -GREENVILLE, SC
l 00 VEROAE BOULEVARD • 29607-3825
P.O. Box 16778 • 29606-6778
803/281-0030 -803/281-0288 FAX
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•
Ms. Giezelle S. Bennett
US Environmental Protection Agency
December 19, 1994
Page 2
As evident from this schedule, a 90% design submittal will be provided in April 1995 to US EPA for a
source area ground water remedy. The source area remedy will either consist of an anaerobic
microbial dechlorination system that is currently being tested by DuPont Environmental Remediation
Services (DERS) at the site, or a conventional pump-and-treat system incorporating extraction wells,
an air stripper, and an infiltration.gallery. The enclosed construction schedule has been revised to
indicate that the system and/or additional wells will be constructed in time to meet the projected start-
up deadline of December 1995. The source area system will not involve a separate bidding process,
so that construction can begin immediately after the source area final design is approved by US EPA.
We hope that the information contained in this submittal is satisfactory to allow your approval of
Prefinal Design documents. If so, please contact either Dave Jones at 219-239-0195 or Wayne Barto
at 615-691-5052 to establish a date for submittal of Final Design documents incorporating all approved
revisions. Due to the holidays, we would, of course, appreciate your consideration for allowing us to
make this submittal within a reasonable time frame following January 1, 1995.
Thank you for your continued cooperation and assistance on this project.
Sincerely,
RMT, Inc.
Project Manager
PAF/fhj
Enclosures
cc: Macon/Dockery Site Group Members
Wayne Barto, de maximis
Kevin White, DERS (with schedule only)
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1.
2.
3.
PREFINAL REPORT COMMENTS
Page 1-1, Para 3. The source control paragraph needs to be updated.
RESPONSE: The referenced paragraph states the requirements of the Order for Lagoon 7
and Lagoon 1 O wastes. The second and third full paragraphs on page 1-2
provide the requested update.
The groundwater recovery system was designed using a two-dimension numerical model
assuming an Isotropic porous media. In view of the change to the hydrogeologlc model
for the site, the numerical model Is only of limited value and should be reevaluated. After
mapping permeability trends In the transition zone and bedrock, the data should be
examined using a three-dimension numerical model. ·
RESPONSE: The Flowpath model was used to predict likely flows and capture zones using
the available data. The MDSG's consultants reviewed the recent findings and
revised the design with sufficient capacity to handle much higher flows than
predicted, thereby eliminating the need for a change in hydrogeology models.
We believe that conducting a three-dimensional modelling effort at this point
would not cause a revision of the system design but would greatly increase
the cost and duration of the design phase.
Page 3-16. The text states that extraction well Installation may Include using a bentonite
slurry powder, tremled Into the well, In place of using bentonlte pellets as an annular seal
above the sand pack. This procedure Is Inconsistent with the specifications In Appendix
S, Section 4.2. It Is also not recommended as a well construction procedure, for the
following reasons:
*
*
*
Bemonlte pellets will hydrate In the well bore, which should form a tighter, more
solid seal than the bentonlte slurry. A slurry may not prevent grout migration Into
the sand pack, because of grout Jetting through the bentonlte slurry seal as the
grout exits from the tremle pipe at a high velocity.
A bentonlte slurry seal might be more difficult to •tag• than a bentonlte pellet seal,
potentially resulting In grout emplacement beginning below the top of the
bentonlte seal, rather than at the top of the seal.
The EPA Region IV ESD Standard Operating Procedures and Quality Assurance
Manual, 1991, specifies that a bentonite pellet seal should be used. However, If
there Is some condition unique to this site that makes use of a bentonlte slurry
preferable to the ESD-recommended bentonlte pellet seal, then It would be
permissible to use the bentonlte slurry. There Is no Information presented In the
design report to Indicate this Is the case.
RESPONSE: The text has been revised as follows:
"The annular space around the well screens will be packed with clean washed
silica sand having a grain size appropriate to the screen slot size. The sand
pack will be emplaced by tremie pipe and will extend approximately two feet
above the top of the screen. A bentonite seal having a minimum thickness of
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4.
5.
6.
7.
8.
approximately two feet will be placed above the sand pack. If the top of the
sand is less than 50 feet below land surface, bentonlte pellets will be dropped
down the annular space. The bentonite pellets will be added a few at a time
to minimize the chance of bridging. If the top of the sand pack is greater than
50 feet below land surface, the bentonlte pellets may be placed via tremie
pipe. A bentonlte slurry made of potable water and bentonite powder may be
used tt unusual conditions prevent the use of bentonite pellets to create the.
seal. If a bentonlte slurry is employed as a seal, this slurry will be placed via a
tremie pipe set near the top of the filter pack."
Page 3-19, Last Bullet. Change reference for 'Appendix G" to 'Appendix Q".
RESPONSE: The text has been corrected.
Page 3-19, Last Bullet. The statement Is Incorrect; the pump Is controlled by levels In the
air stripper reservoir. The pump operation will not necessarily be continuous. Revise
paragraph accordingly.
RESPONSE: This paragraph describes the operation of the centrttugal pumps {also known
as "prime movers") used in the jet pump system, and not the air stripper
effluent pumps. The following text will be added as a separate bullet at the
bottom of page 3-14:
• "The air stripper effluent pumps are controlled by level switches located in the
air stripper sump and by differential pressure switches located across the
discharge bag filter and metals removal columns. The pump will start if the
water level in the air stripper sump reaches the high level switch, and the
pump will stop when the water reaches the low level switch or tt the metal
removal columns or the bag filter are unable to operate due to high differential
pressure. A control narrative is included in Appendix Q to detail pump
operations."
Page 3-20. Delete the last sentence.
RESPONSE: The last sentence has been deleted.
Page 3-20, Bullet 6. Recommend Including cover for the equipment with at least an open-
sided 'ramada" sun/rain roof. This will help In easing maintenance repairs during rain
showers.
RESPONSE: The system has been designed without a roof to facilitate column exchange
operations and to accommodate future equipment additions tt necessary. The
MDSG does not consider a roof to cover the treatment pads warranted for
relatively infrequent maintenance work in inclement weather in light of the
need for column access and system flexibillty.
Page 3-21, Bullet 2. Verify that this statement applies to the Upper and Lower Dockery
systems as well as the Macon system.
RESPONSE: The statement applies to all three systems. Each system can continue to
operate tt one column is removed for servicing.
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9.
10.
11.
12.
13.
14.
Page 3-22, Bullets 7-9. Add a reference In this section to the process control narrative
given In Appendix Q.
RESPONSE: The following sentence has been added to the last bullet on page 3-22:
"A control narrative is included in Appendix Q that describes equipment
interlocks."
Page 3-26, Paragraph 3. Include here the air stripper air emission tables attached to the
Response to Intermediate Design Report Comments or refer to Appendix L and Include
the tables there. ·
RESPONSE: The paragraph has been revised by referring the reader to Appendix L, where
the tables have been added.
Figure 4-1. The schedule does not Include O&M contractor selection. The completion
reports for vessel removal and Lagoon 10 removal have been deleted. When will these
reports be submitted?
RESPONSE: O&M contractor selection will be conducted throughout 1995 through
identttication of, and interviews with, qualified individuals and companies. The
schedule requires that a contractor be selected by 11-13-95, which is the
beginning date for O&M Training. The Lagoon 1 o waste and vessel removal
tasks were completed in November. The completion report for both activities
will be submitted in January 1995.
Appendix L. Include material balances for the groundwater constituents and air
calculations.
RESPONSE: Material balances and air emission calculations tor the three air strippers and
the SVE untt will be included in Appendix L. The attached summary air
emission tables will also be included in Appendix L.
Appendix a, Page 4, Paragraph 6. Discuss how damage to the effluent pump will be
prevented In the occurrence that the filter becomes blocked.
RESPONSE: The referenced paragraph has been revised as follows:
"If the filter becomes too full, Differential Pressure Switch dPISH-1307 will issue
alarm dPAH-1307, located on the Macon Control Panel, and shut down P-
1001, P-1002, P-1003, and Blower B-1001."
The other bag filter descriptions have been similarly revised to state that the
differential pressure alarm will cause the related pumps and blowers to shut
down.
Appendix a, Page 7, Paragraph 4. Add that Pump P-2002 will run without any interlocks
when the H-O-A switch is on HAND.
RESPONSE: The following sentence has been inserted after Paragraph 3:
"In HAND, P-2002 will run without any interlocks."
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- - - -- ----- - -- ----- -
TABLE 3-Z WORST CASE AIR EMISSION RATES
MACON AIR IITAIPPER INFLUENT
POUNDS PER 15 MINUTE POUNDS PEA DAY POUNDS PER YEAR
Cotnnnund FkM'--' Cone. lugtn Actual Th,-hokl Aetu■I Thr•hold Actu.l Th,-hokl
Benzene 48 0,52 3.26e-06 NV 3.13e-04 NV 1.14e-01 8.1
Tetrachloroethene 48 1.90 1.19e-05 NV 1.14e-03 NV 4.17e-01 13000
Trichloroethane 48 6.30 3.95e-05 NV 3.79e-03 NV 1.38e+OO 4000
Toluene 48 2.70 1.69e-05 3.60 1.62e-03 98 5.93e-01 NV
Vin\i I chloride 48 0.00 0.00 NV 0.00 NV 0.00 26
Xylenes 48 5.90 3.70e-05 4.10 3.55e-03 57 1.29e+OO NV
TABLE 3--3 WORST CASE AIR EMISSION RATES
UPPER DOCKERY AIR STRIPPER INFLUENT
POUNDS PER 15 MINUTE POUNDS PER DAY POUNDS PER YEAR
Compound Flow' (gpm) Cone. (ug/1) Actu.l ,........, Actual Th...hokl Actual ,.,..hold
Benzene 6 0.00 0.00 NV 0.00 NV 0.00 8.1
T etrachloroethene 6 1.70 1.330-06 NV 1.28e-04 NV 4.66e-02 13000
Trichloroethane 6 2.50 1.96e-06 NV 1.88e-04 NV 6.86e-02 4000
Toluene 6 2.00 1.57e-06 3.60 1.SOe-04 98 5.49e-02 NV
Vinvl chloride 6 0.00 0.00 NV 0.00 NV 0.00 26
Xvlenes 6 25.00 1.96e-05 4.10 1.88e-03 57 6.86e-01 NV
TABLE 3-4 WORST CASE AIR EMISSION RATES
LOWER DOCKERY AIR STRIPPER INFLUENT
POUNDS PER 15 MINUTE POUNDS PER DAY POUNDS PER YEAR
c-pound Flow (gpm) Cone. (ug/f) Actu.l Threshold Actual Th,-l,old Actual Th,-hokl
Benzene 28 0.25 9.14e-07 NV 8.77e-05 NV 3.20e-02 8.1
Tetrachloroethene 28 0.00. 0.00 NV 0.00 NV 0.00 13000
Trichloroethane 28 1.25 4.57e-06 NV 4.38e-04 NV 1.60e-01 4000
Toluene 28 0.00 0.00 3.60 0.00 98 0.00 NV
Vinvl Chloride 28 0.00 0.00 NV 0.00 NV 0.00 26
Xylenes 28 0.25 9.14e-07 4.10 8.77e-05 57 3.20e-02 NV
NV = No Value Given
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TABLE 3-5 COMBINED AIR STRIPPER WORST CASE AIR EMISSION RATES
Pounds r er 15 minutes Pounds oer dav Pounds ner vear
' Comoound Actual Threshold Actual Threshold Actual Threshold I
Benzene 4.17E-6 NV 4.01e-04 NV 1.46e-01 8.1
Tetrachloroethen 1.32E-5 NV 1.27e-03 NV 4.64e-01 13000 e
Trichloroethene 4.60E-5 NV 4.42e-03 NV 1.61 4000
Toluene 1.85E-5 3.60 1.77e-03 98 6.46e-01 NV
Vinvl chloride 0.00 NV 0.00 NV 0.00 26
Xvlenes 5.75E-5 4.10 5.52e-03 57 2.01 NV
TABLE 3-6 SVE UNIT WORST CASE AIR EMISSION RATES
Pounds Der 15 minutes Pounds .u:or dav Pounds oer vear
Comnound Actual Threshold Actual Threshold Actual Threshold
Benzene 2.8E-7 NV 2.7E-5 ' NV 9.9E-3 8.1
Tetrachloroethen 4.3E-3 NV 0.42 NV 153 13000
e
Trichloroethene 6.9E-6 NV 6.63E-4 NV 2.4E-1 4000
Toluene 2.4E-5 3.60 2.3E-3 98 8.4E-1 NV
Vinvl chloride 0.00 NV 0.00 NV 0.00 26
Xvlenes 2.1 E-3 4.10 0.20 57 73 NV
TABLE 3-7 MACON/DOCKERY SITE WORST CASE AIR EMISSION RATES
Pounds oer 15 minutes Pounds ner dav Pounds oer vear
Comnound Actual Threshold Actual Threshold Actual Threshold
Benzene 4.3E-6 NV 4.1 E-4 NV 1.6E-1 8.1
Tetrachloroethen 4.4E-3 NV 4.21 E-1 NV 153.4 13000
e
Trichloroethene 5.3E-5 NV 5.1 E-1 NV 1.85 4000
Toluene 4.2E-5 3.60 4.2E-3 98 1.50 NV
Vinv I chloride 0.00 NV 0.00 NV 0.00 26
x,Ienes 2.1E-3 4.10 2.1 E-1 57 75 NV
NV = No Value Given
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15.
16.
17.
Appendix a, Page 8, Paragraph 1. Explain why the well pumps wlll STOP at high level. ·
Should this not be th_e level at which they START? Explain why the well pumps are being
controlled from the air stripper sump at low-level In addition to the control coming from
the feed tank at high-level.
RESPONSE: The text references the Upper Dockery system, which is a submersible pump
system. A high level alarm in the feed tank indicates that flow to the treatment
system has slowed or stopped, so the wells should stop pumping. The low
flow switch referenced at the end of the first paragraph measures air flow from
the blower. If no air is blowing into the air stripper, the system shuts down to
prevent the discharge of untreated water.
Appendix S, Section 02673, part 3.1. This section states that the well drilling contractor
should be certified by the state of South Carolina. Since the site Is In North Carolina, the
contractor should be certified to drill wells In North Carolina.
RESPONSE: All references to "South Carolina" in paragraph 3.1.3 have been revised to
"North Carolina."
The state has these fundamental questions about the groundwater:
a. What Is the vertical extent of contamination? Is there contamination In the
bedrock aquifer?
RESPONSE: Although there is no specttic analY1ical data concerning the bedrock aquifer,
the concentrations of contaminants in bedrock, if present, are expected to be
significantly less than those in the saprolite aqutter, since there is no indication
of a separate solvent phase. It is expected that higher horizontal flows
exhibited in the partially weathered rock transition zone above bedrock are
likely to intercept the contaminant plume. The recovery wells will be installed
and screened through the transition zone to the top of competent bedrock,
which will also aid in preventing migration into the bedrock aquifer and will
intercept the greatest mass of contaminants.
b. Piezocones were completed In order to locate conductive zones? Were
conductive zones located?
RESPONSE: Due to limitations of the direct-push technology, piezocones completed in the
spring of 1993 were not successful in locating conductive zones within the
water table, though shallower zones were identified (i.e., cobble layers).
Traditional auger methods used in the fall of 1994 located the conductive
zones within the area of the anaerobic microbial dechlorination study area.
c. Tlle Student I-test was used to compare hydraulic conductivities (k) values for
different regions. Were the k values from the monitoring wells Included In this
determination? Based on the Student's I-test, II was concluded "At a 90 percent
confidence level, no significant differences were found between the mean k values for the
four areas of the site.• In the groundwater flow model, It was necessary to vary the k
values over 3 orders of magnitude to calibrate the models. This contradicts the
conclusion based on the statistics. Are additional pump tests necessary? Please explain.
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18.
19.
RESPONSE: The k values from monitoring wells were not included in the determination.
The k values used to calibrate the model were varied to account for discrete
areas of higher or lower conductivities. The student t-test indicated that the
pump test was indicative of average conditions. No additional pump tests are
necessary for system design. Results of the single pump test were used to
develop a design basis for average conditions, but subsequent findings from
the latest field studies led to a design revision to achieve containment goals
under much higher flow conditions. The system will be optimized after
installation. Addltional extraction wells can be added to each system ij
necessary to achieve capture of each plume.
d. The transition zone between the saprollte zone and the bedrock zone seems to be
a permeable zone that Is conductive to groundwater flow and the movement of
contaminants. What Information has been collected to describe this zone? What Is the
permeability distribution for this zone? What Is Its thickness and map distribution?
Please provide cross-sections showing the transition zone, structure contour maps
showing the top of bedrock surface, and lsopach maps showing the thickness of the
transition zone and the saprollte zone.
RESPONSE: We do not have sufficient data to provide realistic cross-section maps of the
transition zone across the site. The only available detail of the transition zone
is in the vicinity of well MW-9. The recovery wells will be installed to the top of
bedrock at each site, intersecting the transition zone. The current design
already accommodates the higher flow rates expected to be encountered in
the transition zone. Therefore, the MDSG does not believe that the requested
maps will alter the design or expedite the remedy.
e. The results of analyses of groundwater from MW-21 show that the western
boundary of the Upper Macon plume has not been adequately defined. What additional
work Is being planned to define the extent of this plume?
RESPONSE: Analytical results at MW-21 indicate that the plume boundary has been
defined. The locations of extraction wells for the Upper Macon site will be
adequate to contain the plume while source area remediation is achieved. An
intensive investigation to determine the exact line along which constituents are
no longer detected is not warranted based on the analytical results at MW-21.
A survey must be made of all off-property wells within 2,000 feet, and a dally pumping rate
ascertained for each well. Such data should be utlllzed when designing the monitoring
program for the site.
RESPONSE: A survey of private wells located within a one-mile radius of the site was
conducted during the RI (please reference the RI Report, page 3-25). It is very
unlikely that residential wells several hundred feet away from the property
boundary and upgradient of the source areas can have any effect on the
operations or progress of the remedy. Therefore, we disagree that the
referenced information could cause a revision of the monitoring program.
Comments that were not addressed satlsfactorlly:
a. General Comment No. 2. This comment needs to be addressed In terms of source
area extraction wells also.
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RESPONSE: As stated in the previous response to the referenced comment, operation of
the SVE system is not expected to produce upswelling of any signtticance that
will interfere with system operations.
b. Specific Comment No. 1. As expressed by EPA on numerous occasions, this
document should be a stand alone document, and as such, the PAP Information should
be Included.
RESPONSE: This document is not a stand-alone document. Once approved, the Final
Design is incorporated into the Order, which already lists the responsible
parties. The MDSG disagrees with US EPA's request to provide this
information in the design submlttal.
c. SC No. 4. This needs to be updated. The paragraph Is outdated as of the ESD.
RESPONSE: The text was updated in the Prefinal Design submlttal. The revised paragraph
can be found at the top of Page 2-15.
d. SC No. 5. The footnotes are stlll not complete. What Is B, C, DL?
RESPONSE: The DL and C designations are already explained in the footnotes. The
following text will be added to the last note footnote of Table 2-1:
''The following suffixes were added to the end of the sample labels: "A"
designates that the sample is the shallower of two ground water samples or
the only ground water sample collected at that location; "B" designates that
the sample is the deeper of two ground water samples collected at that
location."
e. SC No. 13. This sentence needs to be Included In the text?
RESPONSE: We do riot believe that the definition of compliance monitoring point is
necessary in this context.
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1.
2.
3.
4.
5.
6.
7.
SPECIFICATIONS COMMENTS
Division O sections should be Included.
RESPONSE: Division O sections will be included in the bid package, but not in the
Remedial Design submittal.
Bid comparison sheets should have been Included In this aubmlttal.
RESPONSE: Bid comparison sheets will not be submitted to US EPA. The name,
qualifications, and experience of the successful bidder will be submitted to US
EPA for approval.
A specification section for construction scheduling Is needed.
RESPONSE: A specttication for construction scheduling has been added.
Explain why Section 01410. Testing Laboratory Services was not Included In this
submittal.
RESPONSE: A specification for Testing Laboratory Services has been added.
The Division 1 specifications (especially Submlttals and Quality Control) give the
contractor Insufficient direction. Many generalities are stated using vague, catch-all
language that has no enforceable meaning. As an example, Section 13235 and 13236
refer to Section 01300 for submittal procedures; however, Section 01300 gives no
direction on when to make submittals, quantity of submlttals, and distribution of
submlttals.
RESPONSE: The bid package will have the necessary direction to contractors for
submittals. These will not be revised in the current design submittal.
Does the Committee have a preference on how they want the main control panel
physically laid out? If so, then some direction In the form of specifications or drawings
should be Included In the design package.
RESPONSE: The drawings and specifications provide the contractor with description of the
panel inputs and items to be included in the enclosure. The contractor has
the discretion to lay out the arrangement of the panel. The Remedial Engineer
will review the contractor's shop drawings to determine if the layout is
appropriate.
Include specifications on Instrumentation (I.e., pressure Indicators, flow meters, level
Indicators, transmitters, etc.).
RESPONSE: Instrumentation specifications have been added.
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1.
2.
3.
4.
5.
DRAWINGS COMMENTS
Drawings K-01, K-02, and K-03. For completeness, Include a legend for symbols used on
the P&IDs.
RESPONSE: A separate drawing, K-00, has been added as a legend for symbols used on
the P&IDs.
Drawings K-01, K-02, and K-03. Indicate that the metals treatment system(s) Is a package
system. If this Is not the case, then Include mechanlcal drawings and/or data sheets (In
the Specifications).
RESPONSE: The drawings have been revised to indicate that the metals treatment columns
are package systems.
Drawing K-01. Denote that the box around the air stripper Indicates "Package System·.
RESPONSE: The drawing has been revised as requested.
Drawing K-01, K-02, and K-03. Explain why the pressure Indicator associated with the air
stripper Is measuring the water head as opposed to the air pressure In the blower llne.
RESPONSE: The drawings have been revised to show the pressure indicators above the
sumps and above the water level switches. These pressure indicators are
measuring operating pressures inside the air strippers.
Drawing P-01. One set of feed/return llnes should Indicate Lower Macon. Currently both
indicate Upper Macon.
RESPONSE: The drawing has been revised to indicate the Lower Macon line.
6. Drawing C-02. Physically tie In the well locations.
RESPONSE: The well location coordinates are now shown for the Dockery Site on Drawing
C-04 and for the Macon S~e on Drawing C-05.
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1.
2.
3.
4.
OPERATIONS AND MAINTENANCE PLAN COMMENTS
Pages 1-2 and 1-3. These pages discuss a consent decree. This work Is under a UAO,
please change these paragraphs.
RESPONSE: Page 1-2, fourth paragraph, first sentence will be changed to:
"The O&M Plan is a major project deliverable and milestone called for in the
Remedial Design Schedule, Unilateral Administrative Order and Statement of
Work (SOW)."
Page 1-3, third paragraph, first sentence will be changed to:
"The Macon/Dockery Unilateral Administrative Order requires that the
Prefinal/Final Design Report include, at a minimum, the following: ... :·
Page 1-27, Section 1.7. This section does not provide any Information on Process
Instrumentation and Control. Suggest referencing Appendix A here.
RESPONSE: The following sentence will be added to the end of Section 1. 7:
"The process instrumentation and control approach for each system is
provided in Appendix A.''
Page 1-29, Section 1.9. It Is recommended that the contractor(s) and equipment vendors
give operator training beyond that given by the RD engineers. Ideally, the operators
would be selected and In the field prior to final completion of construction, thereby giving,
the operators the chance to witness the Installation and to Interface with the constructors,
RESPONSE: The first sentence of Section 1.9 will be revised as follows:
"System Operator(s) will be trained by the remedial contractor,
equipment vendors, and the remedial design engineer.''
Section 1.0. Include a Table of Contents for the O&M Manual that outlines a description
of what Is to be Included In the O&M Manual. Recommend that the O&M Manual Include
(In addition to the contents of the O&M Plan):
a.
b.
c.
Section for as-built drawings, approved shop drawings, and construction photos
Listing of manufacturers with telephone numbers
Spare parts Inventory and suppliers with phone numbers
d. List of special tools required for O&M activities
e. Complete nameplate data for all O&M activities
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f. Sources for services and parts
g. Procedures for obtaining technical support and warranty service along with
telephone numbers
h. Utility requirements
I. Permits
RESPONSE: A Table of Contents for the O&M Manual is presented below. The
recommended contents can be found in the following sections:
Section
1.
2.
3.
A. List of Drawings
B. Section 8.4.1
c. Section 8.3
D. Section 8.3
E. Sections 7.1.2; 7.2.2; 7.3.2; and 7.4.2
F. Section 8.3
G. Section 8.4
H. Section 7.1.1; 7.2.1; 7.3.1; and 7.4.1
I. Appendix K
OPERATION AND MAINTENANCE MANUAL
TABLE OF CONTENTS
ACRONYMS AND ABBREVIATIONS
DOCUMENT CONTROL SHEET
INTRODUCTION
1.1 Background
1.2 Purpose of Manual
1.3 Scope of Work
1.4 Regulatory Requirements
TREATMENT SYSTEM DESCRIPTIONS
2.1 Ground Water Recovery
2.2 Ground Water Treatment
2.3 Soil Vapor Extraction System
DESIGN CONDITIONS AND PRESCRIBED TREATMENT
3.1 Macon Ground Water Extraction Wells and Process Equipment
3.2 Upper Dockery Ground Water Extraction Wells and Process Equipment
3.3 Lower Dockery Ground Water Extraction Wells and Process Equipment
3.4 Macon Soil Vapor Extraction Wells and Process Equipment
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OPERATION AND MAINTENANCE MANUAL
TABLE OF CONTENTS (Continued)
4. PROCESS INSTRUMENTATION AND CONTROL APPROACH
4.1 Organization of Operations Management
4.2 Upper Dockery Ground Water Remediation System
4.3 Lower Dockery Ground Water Remediation System
4.4 Macon SVE Remediation System
5. ORGANIZATION OF OPERATIONS MANAGEMENT
6.
7.
TRAINING OF PERSONNEL
OPERATION OF SYSTEMS
7.1 Macon Ground Water Remediation System Description
7.1.1 System Description and Equipment
7. 1.2 Equipment Name Plate Data
7.1.3 System Start-Up for Ground Water Recovery and Treatment System
7.1.4 Normal Operation
7.1.5 Normal Shutdown
7.1.6 Emergency Shutdown
7.1.7 Troubleshooting and Alternate Operation
7.2 Lower Dockery Ground Water Remediation System Description
7.2.1 System Description and Equipment
7.2.2 Equipment Name Plate Data
7.2.3 System Start-Up for Ground Water Recovery and Treatment System
7.1.4 Normal Operation
7.2.5 Normal Shutdown
7.2.6 Emergency Shutdown
7.2.7 Troubleshooting and Alternate Operation
7.3 Lower Dockery Ground Water Remediation System Description
7.3.1 System Description and Equipment
7.3.2 Equipment Name Plate Data
7.3.3 System Start-Up for Ground Water Recovery and Treatment System
7.3.4 Normal Operation
7.3.5 Normal Shutdown
7.3.6 Emergency Shutdown
7.3. 7 Troubleshooting and Alternate Operation
7.4 Macon Soil Remediation System Description
7.4.1 System Description and Equipment
7.4.2 Equipment Name Plate Data
7.4.3 System Start-Up
7.4.4 Normal Operation
7.4.5 Normal Shutdown
7.4.6 Emergency Shutdown
7.4.7 Troubleshooting and Alternate Operation
7.5 Description and Operation -Auto Dialer
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8.
OPERATION AND MAINTENANCE MANUAL
TABLE OF CONTENTS (Continued)
MAINTENANCE OF SYSTEMS
8.1
8.2
8.3
8.4
Ground Water Remediation System Maintenance Tasks
8.1.1 Mechanical Equipment
8.1.2 Instrumentation and Controls
Soil Vapor Extraction System
8.2.1 Mechanical Equipment
8.2.2 Instrumentation and Controls
Maintenance Supplies and Equipment
8.3.1 Tools and Parts Inventory
8.3.2 Suppliers
Technical Support and Other Services
8.4.1 Manufacturer Warranty Services
8.4.2 Engineering Support
8.4.3 Local Contractor Services
9. HEALTH AND SAFETY
9.1 Health and Safety Plan
9.2 Standard Operating Procedures and Controls
9.3 System Failure Activities
9.3.1 Medical Emergencies
9.3.2 General Emergency Procedures
9.3.3 Personal Injury
9.3.4 Chemical Exposure
9.3.5 Fire or Explosion
9.3.6 Emergency Contacts
10. ROUTINE MONITORING, RECORDKEEPING, AND LABORATORY TESTING
1 0.1 Monitoring Activities and Schedule
10.1.1 Ground Water Remediation System
10.1.2 Macon Soil Vapor Extraction System
10.2 Laboratory Testing
10.3 Personnel and Maintenance Records
10.3.1 Medical Surveillance
10.3.2 Training
10.3.3 Work Logs
10.3.4 Accident Reporting
10.3.5 Maintenance Records
10.4 Systems Reporting and Permitting
List of Figures
List of Tables
List of Drawings (Design and As-Built)
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5.
6.
7.
Page 5-1, Paragraph 1. Include Instructions for the autodialer, especially for alarm
conditions.
RESPONSE: The following description of the autodialer function has been added to
Section 1.7.
The systems are designed to operate continuously unless certain
monitoring devices indicate a problem. Each of the three ground
water treatment systems will be equipped with an autodialer device to
notify designated personnel IT a system shuts down automatically, or IT
power (but not telephone service) is interrupted to the systems. The
autodialer will automatically dial a preset list of telephone numbers in
series until someone acknowledges with a preset code. The
acknowledging party will hear a pre-recorded message describing
which treatment system has shut down. The autodialer will repeat the
list of notifications after a prescribed time period unless someone
manually resets the autodialer at the site.
Page 5-2, Section 5.2. Reference Performance Standards Verification Plan for
sampling frequency and methodology or Include those sections of the plan.
RESPONSE: The following text will be inserted after the first sentence of Section
5.2:
Sampling frequency and methodology will follow the sampling
schedule and procedures as found in the Performance
Standards Verification Plan."
Page 5-2, Last Paragraph. Also submit the report forms to EPA.
RESPONSE: The first sentence of the last paragraph will be revised as follows:
" Results of the sampling analysis will be provided on a
monthly routine to NC DEHNR and the US EPA using
Discharge Monitoring Report Forms (EPA Form 3320-1)."
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1.
2.
3.
PERFORMANCE STANDARDS VERIFICATION PLAN COMMENTS
Page 3-1. A nondlscharge permit Is discussed In Section 3.1.2. If a permit Is
needed, then NC recommends:
• An application for a non-discharge permit, for groundwater remediation systems,
and a fee of $400.00 should be submitted to Permits and Engineering, Water
Quality Section, Division of Environmental Management, Department of
Environment, Health and Natural Resources, P. 0. Box 29535, Raleigh, NC 27626-
0535.
-Please Include with the application:
1) the final design report
2) a soll evaluation of the disposal site conducted by a solls scientist (The solls at
each specific Infiltration gallery should be described. Provide a minimum of 3
borings at each of these locations or the equivalent Information to a minimum 7
foot depth), and
3) the manufacturer's performance specification for the diffused aeration system
which demonstrates that the system performance will In fact reduce the Influent
volatile constituents to the performance effluent requirements.
RESPONSE: The permtt application will be submitted to NC DEHNR wtth the Final.
Design Report and the other requested information and fee. In
response to Item 2, the MDSG has conducted infiltration testing in
accordance wtth an EPA-approved workplan. The permit will be
submitted with those results.
Page 3-2, Section 3.1.4. Results should be sent to EPA with the monthly progress
reports, not upon written request. (As stated In the response to comment no 3).
RESPONSE: The last sentence of Section 3.1.4 has been revised as follows: "US
EPA will be provided copies of all such data with the monthly progress
reports."
Proposed monitoring wells MW24 and MW25 do not appear to be In locations that
can possibly Intercept the migrating contaminant plume as displayed. Please
explain.
RESPONSE: It is agreed that well MW-24 may not intercept the migrating
contaminant plume. The MDSG, therefore, proposes to eliminate MW-
24 altogether. MW-25, however, does lie in the path of the Lower
Dockery plume, and we expect that the well may eventually be
impacted if the remedy is not implemented. The MDSG, therefore,
requests to leave MW-25 as shown.
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1.
2.
CONSTRUCTION HEALTH AND SAFETY PLAN/CONTINGENCY PLAN COMMENTS
Table 7-1. It Is unclear to the reader why respirators with HEPA/organic vapor
cartridges are to be used. According to the Information on pages 4-6 to 4-19,
cartridges should not be used for 57% of the volatile organics found on the site.
Even If detector tube readings for the chemicals listed In this table are all below
the 'maximum range value· and vinyl chloride Is less than 1 ppm, air purifying
respirators are still not appropriate to protect against 36% of the chemicals of
concern. Please explain.
RESPONSE: The protection requirements were set at levels that will not exceed
Threshold Limit Values (or the Permissible Exposure Limit for benzene)
for the contaminants known to be present. While respirators are not
required at these levels, the Health & Safety Plan specifies the use of
respirators as a safety measure until some action is taken to identify
and quantify the constituents in an organic vapor.
Table 7-1. WIii a gas chromatograph be used with the PID/FID? If not, chemicals
cannot be Identified with the proposed Instrumentation, therefore, a concentration
expressed as a volume to volume ratio such as ppm Is meaningless. The
recommended term Is •meter units.•
RESPONSE: The table has been revised by substituting "meter units" or mu for
"ppm".
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1.
2.
3.
RA WORKPLAN COMMENTS
Previous Comment No. 4. Confirmation sampling still Is needed for the SVE
Lagoon 7 cleanup. Why Is this no longer applicable? Is It Included In the SVE
final design report?
RESPONSE The SVE design was broken out as a completely separate design.
The SVE design does include confirmation sampling for Lagoon 7
soils.
Previous Comment No. 12. This Is still not In line with the UAO that was Issued.
THE IQAT TEAM MUST REPORT ITS FINDINGS AND CONCLUSIONS DIRECTLY
TO EPA, AND NOT THROUGH THE PAPS.
RESPONSE: The text in the third sentence of the IQAT description has been revised
to reflect that US EPA will receive all reports simultaneously wtth the
Project Coordinator.
There Is a typo In the schedule both here and In the preflnal report. The schedule
states that the contractor selection process begins on 1 /1 /94, Instead of 1 /1 /95.
RESPONSE: The text in both locations has been corrected.
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