Cenco_FILE DOCKET -171 PGS-OCR

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TO: Brenda Rivers
MEMORANDUM
February 23, 1993
FROM: Katherine O' Neal 1~i0
RE: Public Notice of Post-Closure Plan
Central Transport, Inc.
Charlotte, North Carolina
NCD046148540
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Please run the attached public notice of the Post-Closure Plan for
Central Transport, Inc. on March 3, 1993.
cc: Bill Hamner
Jimmy Carter
• •
NOTICE OF POST-CLOSURE
HAZARDOUS WASTE MANAGEMENT UNITS
Central Transport, Inc., located at 600 Melynda Road, Charlotte,
North Carolina, has proposed a post-closure plan for two (2)
closed surface impoundments which were used to treat and store
hazardous wastes. The post-closure plan has been reviewed by the
North Carolina Department of Environment, Health, and Natural
Resources, Hazardous Waste Section. Within thirty (30) days of the
date of publication of this notice, any person may submit written
conunents and request modification of the post-closure plan or
request a hearing.
A copy of the post-closure plan can be reviewed during office hours
(8:00 a.m. to 4:00 p.m.} Monday through Friday at the Hazardous
waste Section, 401 Oberlin Road, Suite 150, Raleigh, North
Carolina 27605. Any persons with questions or conunents regarding
the post-closure plan should contact Ms. Katherine O'Neal in
Raleigh at [phone].
r .-•
William F. Harvner, Ph.D.
December 28, !992
Page 2
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consideration of semi-annual monitoring for the post closure period. We believe this
approach adequately addresses environmental issues at the site, considering:
1) The contaminated soils and sludges has been removed.
2) Hydraulically downgradient wells at the site are all clean.
3) The ground water contamination at MW7 /8 is being addressed under
separate agreement.
4) This approach is in full compliance with 40 CFR 265.
c) Section F-2e(5) (h), (i), and (k) has been revised to state that the procedures
specified in the Sampling and Analysis Plan will be followed.
d) Section F-2e(5)(j) has been revised to state that SW-846 methods 8240 and 8270 will
be used for volatiles and semi-volatiles analyses. Also, the specific inorganic
constitue):lts to be monitored and the analytical methods to be used is provided.
e) Section F-2e(5)(1) has been deleted.
Four ( 4) copies ,of the revised sections of the closure plan are attached. We trust that this
submittal meets the intent of the regulations and the states objectives. Please direct
comments and questions regarding this letter to the undersigned or Ms. Terry L. Norman
of this office.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
/"1_ 73.f?q Ge~Rest, i>.E.
Vice President
GBR:mjh
Attachments
cc: Terry L. Norman
Steven Shach, P.E.
Marc Fleischaker, Esq. (Arent, Fox et al)
John Doyle, Esq. (Constangy, Brooks and Smith)
Larry Wellington (CTI)
Glen Simpson (CTI)
O'BRIEN & GERE
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William F. Hamner, Ph.D.
September 10, 1992
Page 2
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As specified in the closure plan, CTI must provide verification that the backfill is not
contaminated.
The revised grading plan and cap cross section are shown on Figures 1 and 2, respectively.
Modifications to the Post-Closure Plan
In response to your comments (numbered per your August 24, 1992 letter):
1. CTI will comply with the Section's directive for 30 year post closure monitoring. CTI
expects to petition the Section to reduce the post closure period may be made at a
later date. A revised Post Closure monitoring plan is included in paragraph F-2a
through F-2j of Section F attached.
2. Site security measures will be provided as described in our August 6, 1992 letter.
These modifications are reflected in the revised paragraph F-2b to Section F of the
Closure Plan attached.
3. In accordance with the notice requirements of 40 C.F.R. 265.116 and 265.119 as
adopted in ISA NCAC 13A.0010, CTI will file an appropriate notation on the deed
to the facility property as specified in the applicable regulations. CTI will include a
statement that the waste has been removed. In addition, CTI wishes to preserve the
opportunity, should the post closure period be reduced per 40 C.F.R. 265.117(a)(2)(i)
due to the absence of groundwater contamination, to seek to petition to reform the
deed to eliminate or modify the hazardous waste notification. No such reformation
will be sought unless and until the appropriate findings are made under 40 C.F.R.
254.117(a)(2)(i). These modifications are reflected in the revised paragraph F-4 of
Section F.
In addition, a number of modifications have been made to Section F beginning with Section
F-2 of the Post Closure Plan and are noted below:
4. Monitoring wells MW 6,9, and 10 will be used for background monitoring, and MW
7, 11, 13, and 16 will be used as "downgradient" monitoring wells, as denoted in
paragraphs F-2e(5)a, b, e, and f of Section F. While MW 7 is not currently
downgradient it is included because contamination has been detected in this well.
5. The reference to two on-site flow regimes has been removed from paragraphs F-
2e(5)l(i) and (ii) of Section F as the production well has been taken out of service.
O'BRIEN & GERE
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William F. Hamner, Ph.D.
September 10, 1992
Page 3
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6. Maintenance activities have been revised to include inspection and maintenance of
all run-on and run-off controls as denoted in paragraph F-2f of Section F.
7. A survey plat will be prepared by a professional land surveyor will be filed with the
local zoning authority as denoted in paragraph F-3 of Section F.
8. The cost estimate for closure has been revised per paragraph F-5 of Section F, and
Table 13.
9. The post-closure cost estimate has been revised per paragraph F-7 of Section F, and
Table 14.
We trust that this submittal meets the intent of the regulations and the State's objectives.
Please direct comments and questions regarding this letter to the undersigned or Ms. Terry
L. Norman of this office.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
&~ ~-~--\-(_~+~~)
George B. Rest, P.E.
Vice President
GBR:TLN:dmh
cc: Terry L. Norman
Glen Simpson, (CTI)
Marc Fleischaker, Esq. (Arent, Fox et al)
John Doyle, Esq. (Constangy, Brooks and Smith)
Larry Wellington (CTI)
Steven Shach
Attachments
O'BRIEN & GERE
I
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TASK
I. Water Removal to CMUD
2. Excavation
3. Stabilization
Mobili>ation
Stabi 1 i zati on
4. Disposal
• TABLE 13
Cost Estimate for CTI
Charlotte, North Carolina
Closure Pl an/Post Closure Pl an
Central Transport, Inc.
Charlotte, North C~ro11na
Revised September 9, 1992
Sludge and soils
Transport
10,773 tons total
5. Soil Sampling (Confirm Clean)
6. Backf111 and Final Cover
7, Closure Certification
On-site ln$pection
Report and Certification
8. Surveyor
9. Post Closure Care (per Table 14)
Subtota 1
Engineering/QA/QC (10%)
Subtotal
Administrative and Contingency (15%)
Total Estimated Project Cost
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ESTIMATED COST
$4,410
completed
completed
completed
completed
completed
completed
$239,971
completed
$15,750
$3,150
$901. 218
$1,164,499
$116,450
$1,280,949
$192, 142
$1,473,091
• •
September 10, 1992
F-le Extensions for Closure Time 40 CFR 265.113(al & Cb), 10
NCAC lOF .0033Cg!
At this time, CTI does not submit a petition for a
closure time extension.
F-lf Certification of Closure 40 CFR 265.115, 40 CFR
265.28Q(e), 10 NCAC lOF .0033(g)
An inspector who reports to an independent professional
engineer will be on site during the excavation, stabilization
and removal of the sludge and periodically during the
completion of closure activities. When closure has been
completed, CTI will submit to the State of North Carolina a
written certification both by the company and by the
professional engineer that Lagoons 1 and 2 have been closed in
accordance with this Closure Plan. In addition, the report
any procedures or tasks
which differed from those
Any changes to the approved
will include a description of
performed during the closure
specified in the approved plan.
closure plan will be submitted to the Hazardous Waste Section
for approval.
F-2 Post-closure Plan
Section F.2.a. through F.2.i. constitutes the Post-
Closure Plan for Central Transport, Inc. 's (CTI) surface
impoundments at the Charlotte, North Carolina facility. This
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September 10, 1992
Post-Closure Plan describes the activities to be followed by
CTI following the closure of the surface impoundments. The
Post-Closure care period for this facility is thirty years.
F-2a Post-closure Contact
Name: Glen Simpson, Environmental Director for CTI
Address: Central Transport, Inc.
P.O. Box 7007
High Point, North Carolina 27264
Route 5, Uwharrie Road
High Point, North Carolina 27263
Telephone: [phone] (High Point)
1-800-289-9022 (Charlotte terminal)
[phone] (Charlotte terminal)
Fax: [phone]
F-2b Post-Closure Security
Restricted access to the regraded area will be provided
by enclosing the area with a fence. The fence will be 6 feet
high with three strands of barbed wire around the top of the
fence. A 24 hour watchman at the plant will also be used to
assure that there is no public access.
The groundwater monitoring wells used as part of the
closure and post-closure monitoring will be locked with
padlocks at all times, except during sampling events. The
Environmental Director of CTI, or his designee, will retain
the keys to these locks.
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September 10, 1992
F-2c System Design Description
This section is not applicable to the closure activities
planned for the surface impoundments.
F-2d Inspection Plan
Inspection of the former impoundment area will be made
quarterly by the Environmental Director of CTI, or his
qualified designee. The inspection will consist of a visual
review of the former impoundment area, fencing integrity, and
observations of unusual surface conditions or possible
indications of unusual subsurface conditions. In addition,
all groundwater monitoring wells will be inspected during
semi-annual sampling.
At the time of each inspection, a record will be made in
an inspection log, which is contained in Appendix G. Recorded
information includes: former surface impoundment
identification (Lagoon 1 and Lagoon 2), date and time of
inspection, item or issue inspected, notation of observations
made, and signature of inspector. Any problems observed
during the inspection by CTI's designee will be recorded and
brought to the attention of the Environmental Director. The
Environmental Director is responsible for ensuring that
remedial action is performed on a timely basis and for
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September 10. 1992
documenting the nature of the remedial action in the
inspection log. Copies of inspection logs will be kept on
file at the CTI-Charlotte facility.
F-2e Post-Closure Monitoring Plan
F-2eCll Indicator parameters. waste constituents,
reaction products to be monitored
Chemical analyses of the surf ace waters and the sludges
of the lagoons are summarized on Tables 3, 5, and 6. The class
of compounds that would serve as the best indicator compounds
are the voes and base/neutral extractables. voc's are mobile
(ie, commonly found at the leading edge of contaminant
plumes), have low detection limits, and are not normally
present in ground water. Phthalates, which are base/neutral
compounds, are the most prevalent constituent found in the
sludge.
F-2e(2) Hazardous waste characterization
A discussion of the type, quantity, and concentrations of
constituents in wastes managed at the regulated unit is
included under Section B-1 of the Closure Plan.
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September 10, 1992
F-2e(3l Behavior of constituents
As discussed in Sections B-1 and E-1, ground water
sampling conducted indicates that there has been no release of
hazardous constituents to the ground water at the site.
F-2eC4) Detectability
EPA Method 8240/624 is used to detect voe in ground water
samples. EPA Method 8270/625 for Acid and Base/Neutral
Extractables is used to detect Phthalates in ground water
samples.
F-2e(5l Post Closure Groundwater Monitoring Program
F-2e(5)a Description of wells
The following wells will be sampled during post
closure monitoring: MW 6, 7, 9, 10, 11, 13, and
16.
As discussed under E-1, well locations are shown on
Figure 3 and the revised grading plan. Well
specifications and Ground water Elevations, Boring
Logs, and Well Construction Diagrams are all found
in the Appendices.
F-2e(5)b Representative samples
The background monitoring points will be the
upgradient wells MW 6, 9, and 10. The compliance
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September 10, 1992
monitoring points will be the "downgradient" wells
MW 7, 11, 13, and 16. While MW 7 is not currently
downgradient it is included because contamination
has been detected in this well.
F-2el5lc Locations of background ground-water
monitoring wells that are not upgradient
There are no background wells that are not
upgradient.
F-2e(5ld Background values
Background arithmetic means, variances and standard
deviations for indicator parameters from upgradient
wells will be calculated. Based on an evaluation
of ground water quality data collected during the
four sampling rounds, an appropriate statistical
procedure for comparing upgradient and downgradient
wells will be selected. The statistical procedure
will be selected in accordance with USEPA Guidance
Document entitled "The Statistical Analysis of
Ground Water Monitoring Data at RCRA Facilities",
Interim Final Guidance, Office of Solid Waste,
dated February 1989, following collection of the
fourth round of samples in September 1990.
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September 10, 1992
Ground water quality data collected during the
October 1989, November 1989, and June 1990 rounds
of sampling indicate that no ground water
contamination related to the lagoons exists.
F-2e(5le Sampling Frequency
Ground water samples will be collected from wells
MW 6, 7, 9, 10, 11, 13, and 16 on a semi-annual
basis throughout the post closure monitoring
period.
F-2eC5lf Sampling quantity
The background monitoring points will be the
upgradient wells MW 6 1 9, and 10. During each
semi-annual round, one sample from each of these
wells will be collected and analyzed. The total
number of background samples will be three.
F-2e(5)g Sampling, Analysis and Statistical
Procedures
The Supplemental Work Plan includes procedures for
sample collection, sample preservation, sample
shipment, analytical methods, and chain of custody
controls.
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eeptember 10. 1992
Statistical comparison procedures will be as
discussed under Section F-2e(5)d.
F-2e(5)h Sample collection
Sample collection procedures and techniques are
discussed in the Work Plan (Appendix E) under
Ground Water Sampling and Analysis -Ground Water
Sampling Protocol.
F-2eC5li Sample preservation and shipment
sample preservation and shipment techniques are
discussed in the following parts of the Work Plan
(Appendix E) under Ground Water Sampling and
Analysis -Ground Water Sampling Protocol.
F-2e(5)i Analytical procedure
Samples will be analyzed for the following
parameters:
Volatile organics
Acid/Base Neutral
Extractables
RCRA Metals
F-2e(5lk Chain of custody
EPA Method 624
EPA Method 625
Chain of custody procedures are discussed in the
Work Plan (Appendix E), under Ground Water Sampling
and Analysis -Ground Water Sampling Protocol.
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Septe!Dber 10, 1992
F-2e(5ll Annual determination
The uppermost aquifer on the site is the bedrock
aquifer, as discussed under E-2-The annual
determination of flow direction will be based on
static ground water elevation measurements in all
the bedrock monitoring wells. Elevation
measurements-will be made in conjunction with
sampling rounds. Elevation measurements will be
made as described in the Work Plan, (Appendix E),
under Ground Water sampling Protocol.
F-2e(5)l(il Flow Direction
Potential flow direction will be perpendicular to
contour lines that will be drawn to represent equal
ground water elevations. The potential flow
direction will be toward lower ground water
elevations. The ground water elevation data will
be tabulated in a manner similar to Table 7, and
will be plotted in a manner similar to Figure 7.
F-2e(5l1Ciil Flow rate
The hydraulic gradient will be derived from the
contour lines that will be drawn. Using the values
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September 10, 1992
for hydraulic gradient, ground water flow
velocities will be calculated as described in the
Hydrogeologic Investigation Report.
It should be noted that, of the three variables in
the velocity equation, the only one that can vary
with the passage of time is the hydraulic gradient.
on October 20, 1989, in-situ hydraulic conductivity
tests were performed on wells MW6 through MWll to
estimate the hydraulic conductivity (or
permeability) of the screened aquifer material.
The hydraulic conductivity was calculated by
measuring the rate of recovery of the water level
immediately following the development of each well.
The Hvorslev method was used to calculate the
hydraulic conductivities.
The in-situ hydraulic conductivity tests will not
be repeated each year.
Similarly, while varying ground water elevations
may result in varying ground water flow velocities
and in varying potential flow directions, the
hydraulic pathways (a joint or fracture) needed for
ground water flow in a fractured bedrock aquifer
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September 10. 1992
will not vary with the passage of time. The
fracture trace analysis described in the Work Plan
and the supplemental Report will not be repeated
each year.
F-2eC5lm Statistical Determination
Statistical procedures will be as discussed under
F-2e(5).
F-2e(5Jn Results
It is estimated that laboratory results will be
received approximately 30 days after any given
sampling round. It is estimated that up to 30 days
will be required to perform the statistical
analysis,
received.
once laboratory results have been
Thus, an evaluation as to whether there
has been a statistically significant increase over
background values for each parameter monitored at
the compliance point wells will be available 60
days after the completion of any given sampling
round.
F-2f Maintenance Plan
The area of the former surface impoundments, following
removal of the solidified materials, shall be capped, and
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septemher 10, 1992
seeded. Reseeding, fertilization and mowing will be performed
as part of the facility's regular landscaping care procedures.
Inspection and maintenance of all run-on and run-off control
will be performed during the semi-annual inspection.
F-2q Special Waste Management Plan
This section is not applicable to the CTI Charlotte
terminal, as the surface impoundments were not used to contain
chlorinated-dioxins, -dibenzofurans or -phenols.
F-2h Land treatment
The CTI facility does not operate a land treatment unit,
thus this section is not applicable to this closure plan.
F-2i Personnel Training
Inspection and routine procedures will be carried out by
qualified personnel (Environmental Director or his designee)
from CTI.
Ground water sampling will be performed by qualified
contracted personnel. Required training for contracted
personnel will depend on the activity performed. Only
appropriately trained and qualified personnel will be
contracted for the ground water sampling.
Employees involved with post-closure activities, such as
inspection and recordkeeping, will receive on-the-job training
F-26
O'BRIEN & GERE
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September 10, 1992
specific to their job assignment. This training will be
performed by the Environmental Director, or contracted
personnel familiar with this project.
F-2i Post Closure Certification
CTI will provide post closure certification in accordance with
40 CFR 265.120.
F-3 Notice to Local Land Authority
A copy of the survey plat, prepared and certified by a
professional land surveyor, will be filed with the local
zoning authority in accordance with 40 CFR 265.116 and
265.119.
F-4 Notice in Deed
In accordance with the notice requirements of 40 C.F.R.
265.116 and 265.119 as adopted in 15A NCAC 13A.0010, CTI will
file an appropriate notation on the deed to the facility
property as specified in the applicable regulations. CTI also
intends to include a statement indicating that most of the
waste has been removed. In addition, CTI wishes to preserve
the opportunity, should the post closure care period be
reduced per 40 C.F.R. 265.117(a) (2) (i) due to the absence of
groundwater contamination, to seek to petition to reform the
deed to eliminate or modify the hazardous waste notification.
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September 10. 1992
No such reformation will be sought unless and until the
appropriate findings are made under 40 C.F.R.
254.117(a) (2) (i).
F-5 Closure Cost Estimate 40 CFR 270.14(bl (15), 10 NCAC 10F
.0034 (bl (5)
Table 13 itemizes the costs expected to be incurred
during closure of the site. The cost to complete the project
which includes post closure monitoring is currently estimated
at $1.47 million.
F-6 Financial Assurance Mechanism 40 CFR 270.14(b!C1S), 10
NCAC 10F .0034(b)(S)
A letter of credit has been issued by the North Carolina
National Bank to CTI for 2.5 million dollars to cover both
closure and post closure costs.
F-7 Post-Closure cost Estimate
A Post-Closure cost estimate for CTI' s Charlotte, NC
facility is presented in Table 14. The total 30 year cost for
post closure monitoring is $901,218.
All on-site post-closure work will be supervised and
performed by qualified CTI or contracted personnel. However,
the cost estimate has been prepared assuming all activities
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September 10, 1992
F-9 Liability Requirements 40 CFR 270.14!bl !17), 10 NCAC 10F
• 0034 (b) (5)
The liability requirements for sudden and nonsudden
accidental occurrences do not apply to CTI's lagoons. The
requirements, set forth at 40 CFR 265.147, are intended to
provide coverage for bodily injury and property damage to
third parties caused by sudden or nonsudden accidental
occurrences arising from operations of the facility. CTI's
lagoons are not, and have not been for some time, a facility
in operation. In fact, they are ready to be closed
imminently.
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REFERENCES
1. Cederstrom, D.J.; Boswell, E.H.; and Tarver, G.R.,
"Summary Appraisals of the Nation's Ground-Water
Resources-South Atlantic-Gulf Region," USGS
Professional Paper 813-0, 1979.
2. Conner, J.R., Li, A.; "Stabilization of Hazardous
Waste Landfill Leachate Treatment Residues".
Presented at Gulf Cost Hazardous Substance Research
Center Symposium on Solidification/Stabilization.
February 15-16, 1990.
3. Legrand, H.E. and Mundorff, M.J.,
Ground Water in the Charlotte
"Geology and
Area, North
Carolina," North Carolina Department of
Conservation and Development Bulletin No. 63,
prepared cooperatively with the USGS, 1952.
4. Stabilization/Solidification of CERCLA and RCRA
wastes, Physical Tests, Chemical Testing
Procedures, Technology screening, and Field
Activities. EPA/625/6-89/022. May 1989. Office
of Research and Development, U. s. Environmental
Protection Agency.
O'BRIEN I:> GERE
l_ __ _
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REFERENCES
(continued)
•
September 10. 1992
5. Tittlebaum, M.E., Cartledge, F.K., Engels, S.;
"State of the Art on Stabilization of Hazardous
Organic Liquid Wastes and Sludges." CRC critical
Review in Environmental Control, 15, 1985, pp. 179-
211.
6. Wilson, Frederick Albert, "Geophysical and Geologic
Studies in Southern Mecklenburg County and
Vicinity, North Carolina and South Carolina," USGS
Paper OF83-0093, 1983.
F-32
O'BRIEN & GERE:
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Mr. Lawrence Wellington
August 24, 1992
Page 2
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As specified in the approved closure plan, CTI must also provide
verification that the backfill is not contaminated. CTI should
also verify that the clay and topsoil are not contaminated.
The following comments concern the modifications to the post
closure plan:
1) Per 40 CFR 265.117(a)(l) as adopted in 15A NCAC 13A .0010 the
post closure care period is thirty (30) years. A decision to
reduce the post closure period may be made by the Section at a
later date. CTI may submit a petition at a later time during
the post closure period to review the data at that time to
determine if a "reduced [post closure] period is sufficient to
protect human health and the environment".
2) A waiver of site security requirement cannot be granted as
requested; however, providing restricted access to a landfill
by enclosing the area with a fence and having a 24 hour
watchman at the plant is adequate to meet the requirements of
40 CFR 265.ll?(b) as adopted in 15A NCAC 13A .0010.
3) The notification requirements of 40 CFR 265.116 and 265.119 as
adopted in 15A NCAC l3A .0010 cannot be waived. The notice
must indicate that the land has been used to manage hazardous
waste, that its use is restricted under 40 CFR Subpart G
regulations, and it must provide a record of the "type,
location , and quantity" of hazardous waste disposed. The
Section requires facilities to include the concentration of
constituents remaining in the soils in the record. CTI may
also include a statement indicating that most of the waste has
been removed.
Four (4) copies of a modification to the closure plan and post
closure plan addressing the above deficiencies must be submitted to
this office by September 10, 1992. Failure to submit the revisions
on or before the compliance date may result in enforcement action.
If you have any questions please call Katherine O'Neal at (919)
733-2178.
Sincerely, Y ~ l" \-~ LA {!,t;/7 __ V'-
W' 11 iam F. Hamner, PhfD., Head
ermitting Branch
Hazardous Waste section
WFH/KL0/163-164
cc: G. Alan Farmer, us EPA, Region IV
James A. carter
Judy Bullock
Jesse Wells
Gary L. Honbarrier
John Gibson
Laurie Martin
Douglas L. Roberts
Katherine L. O'Neal
•
WHliam F. Hamner, Ph.D.
August 6, 1992
Page 2
Modifications to the Closure Plan -Protective Cover
•
Regarding the references in the March 25 and July 8 letters to a protective cover (meeting
the requirements of 40 CFR 265.228(a)(2)(iii) as adopted in 15A NCAC 13A.0010), the
following information if offered. Sent under separate cover are the revised final grading
plan and typical cross sections for your review and comment. If possible, please provide
your comments by August 19, 1992, as your comments are needed prior to our submittal of
the drawings to the contractor.
The preliminary design criteria for the final cover were derived from Lining of Waste
Containment and Other Impoundment Facilities, (technical resource document, EPA, 9 /88)
and Final Covers on Hazardous Waste Landfills and Surface Impoundments, (technical
guidance document, EPA, 7 /89). In accordance with the latter document, the recommended
design addresses the requirements of 40 CFR 264 and 265 Subparts G (closure and post-
closure ), K (surface impoundments), and N (landfills). The final cover design would be
comprised of the following layers:
1. A vegetation \soil layer that is 18 inches thick, with a final slope of 3%. It is
O'Brien & Gere Engineers' understanding that the frost layer in North
Carolina is approximately 12" -18", and thus such a soil layer would be
sufficient to protect the clay layer from the actions and effects of frost.
Vegetation will consist of locally adapted perennials with shallow root systems
that can thrive in low nutrient soils. The density of the plants will be such
that cover soil erosion will be no more than 2 tons/acre/year as measured by
the USDA Soil Loss Equation. This layer will be designed so that it requires
minimal maintenance and will be comprised of medium textured soils such as
loam. Refer to Drawing #2.
2. A low permeability compacted soil layer which is 18 inches thick with a
saturated hydraulic conductivity less than or equal to 1 x 10 ·7 cm/sec. The
layer will be free of clods, rocks, debris, cobbles, rubbish, roots, etc that would
increase the permeability or promote preferential water flow pathways. The
specifications will require that soil will be installed in no less than four 6" lifts
and will be compacted at a moisture content which is wet of optimum. A test
fill will be required using soil, equipment and procedures to confirm that
design specs are attainable.
3. Approved backfill from the bottom of the excavation up to the low
permeability soil layer.
O'BHlloN & c;rnf'
•
William F. Hamner, Ph.D.
August 6, 1992
Page 3
•
You will note that this cap does not include a "drainage layer". Based on the results of
recent studies on similar projects, the technical advantages of the drainage layer have come
under question. Experience has suggested that the drainage layer may act as a "wick",
drawing moisture which sustains the vegetation layer, and drawing moisture from the clay
layer, which can cause desiccation cracking of the low permeability layer. We therefore
conclude that the drainage layer is not appropriate for CTI's facility.
Modifications to the Post-Closure Plan
Regarding comment (a) of the March 2S letter, on the length of post-closure care, 40 CFR
26S.117(a)(I) provides that "care for each hazardous waste management unit ... must begin
after completion of closure of the unit and continue for 30 years after that date." Subsection
(2)(i) specifically provides, however, that the post-closure monitoring period may be reduced
by the Regional Administrator. He may (i) "shorten the post-closure care period applicable
... if he finds that the reduced period is sufficient to protect human health and the
environment ... ". The data which have already been submitted demonstrate that a shortened
post-closure care period is appropriate, in that the lagoon sludges have been removed, and
there is no ground water contamination in currently downgradient wells or in the stream.
We recommend that a three-year period be approved. Should ground water monitoring
results during this period indicate that additional post-closure care is necessary, then the
period may be extended at that time.
Regarding comment (b ), on site security measures, per 40 CFR 26S.117(b) as adopted in
ISA NCAC 13A.0010, these regulations apply to facilities at which the land is used to
manage hazardous wastes. The waste at the CTI Charlotte facility has been removed.
Fencing currently surrounds the overall CTI property; this fence runs along the northern,
western and southern border of the former impoundment area (refer to drawing #I). We
propose the addition of fencing along the eastern boundary of the former impoundment
area, to completely enclose the subject area. Entrance to the property is currently
controlled by a dispatcher/nightwatchman who is present 24 hours a day, seven days a week.
Additional security measures that would apply to facilities managing hazardous wastes would
not apply to the Charlotte facility. A~ such, we request a waiver of the requirements related
to site security.
Regarding comment ( c), on monitoring and maintenance activities for the former surface
impoundment area, in accordance with 40 CFR 26S.118(c) as adopted in ISA NCAC
13A.0010, the vegetative cover will be maintained (cut) monthly during the growing season
for such vegetation, and reviewed monthly for maintenance needs in off-season months.
This maintenance will include the removal of vegetation suspected of threatening the
viability of the existing shallow-rooted plants. Deep-rooted plants or weeds that could
potentially disrupt the topsoil layer would also be removed. Monthly inspections of the
O'BHWN & [3ERE
•
William F. Hamner, Ph.D.
August 6, 1992
Page 4
•
condition of both the cap and the vegetation in the former impoundment area will be made.
The inspection will include a review of the items included on the attached updated
Inspection Log, such as cap integrity, signs of erosion, vegetative health/status, signs of
subsurface disturbance such as raised mounds or collapsing soils (e.g. due to burrowing
animals), water ponding and water runoff. Corrective measures will be taken, as
appropriate, to restore the covered area to the initial (design) conditions. Such corrective
measures may include regrading, in order to minimize percolation, removal of brush or
shrubs, and weed control. Should thinning of vegetation be observed that is indicative of
insect damage, an extermination program will be initiated, and overseeding will be done in
order to maintain a dense and uniform vegetative cover. Well inspection will also be
conducted monthly. The integrity of the well cover, Jock and casing will be reviewed.
Damaged materials will be replaced and/or repaired, as appropriate, in order to maintain
the integrity and usefulness of the well. Should a well used in subsequent monitoring be
discovered to be damaged beyond repair, the DEHNR will be notified as to an appropriate
replacement location, procedure, and schedule.
Regarding comment (d) related to a new survey plat and comment (e), on recording a
notice in the property deed, 40 CFR 265.119 requires a permanent notation on the facility's
deed that "the land has been used to manage hazardous waste; and [i]ts use is restricted
under 40 CPR Subpart G". Normally, such a recordation is required within 60 days after
certification of closure. However, this should be unnecessary at CTl's facility because the
waste (sludge) at the site has been removed. The regulatory requirement contemplates a
"dirty closure" with hazardous wastes in place; in CTI's case the closure is "dirty" solely
because of allegedly related ground water contamination at MW7 and MWS. Consequently,
CTI requests a waiver of this requirement, as well as that for the related survey plat for such
a property.
Regarding comment (f), requesting an updated post-closure cost estimate. This updated cost
estimate is presented in the attached revised Tables 13 and 14 (numbered to correspond
with the original tables in the 1991 Closure/Post Closure Plan). Pending your approval of
the above noted request for a 3-year monitoring period, please note that the tables still
reflect a 30-year monitoring period (as previously submitted).
U'DRIEN & hERE
•
Will.lam F. Hamner, Ph.D.
August 6, 1992
Page 5
•
We trust that this submittal meets the intent of the regulations and the State's objectives.
Please direct comments and questions regarding this letter to the undersigned or Ms. Terry
Norman.
Y ery truly yours,
O'BRIEN & GERE ENGINEERS, INC.
~R(s?,P.~~
Vice President
GBR:mjh
cc: Terry L. Norman
Glen Simpson (CTI)
Marc Fleischaker (Arent Fox)
John Doyle (Constangy, Brooks and Smith)
Larry Wellington (CTI)
U'DRIFN & CiCRE
•
William F. Hamner, Ph.D.
August 6, 1992
Page 2
•
Please contact the undersigned or Ms. Terry Norman if you have any questions. Thank you
for your understanding on this matter.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
/t. 73.-Z+ -G~{i3. Rest, P.r.,
Vice President
GBR:mjh
cc: Terry L. Norman
Glen Simpson (CTI)
Marc Fleischaker (Arent Fox)
Laurel Bedig (Arent Fox)
John Doyle (Constangy, Brooks and Smith)
Larry Wellington (CTI)
O'BRIE~I & GE'RE
• •
William F. Hamner, Ph.D.
August 4, 1992
Page 2
Modifications to the Closure Plan · Protective Cover
Regarding the references in the March 25 and July 8 letters to a protective cover (meeting
the requirements of 40 CFR 265.228(a)(2)(iii) as adopted in 15A NCAC 13A.0010), the
following information if offered. Sent under separate cover are the revised final grading
plan and typical cross sections for your review and comment. If possible, please provide
your comments by August 19, 1992, as your comments are needed prior to our submittal of
the drawings to the contractor.
The preliminary design criteria for the final cover were derived from Lining of Waste
Containment and Other Impoundment Facilities, (technical resource document, EPA, 9/88)
and Final Covers on Hazardous Waste Landfills and Surface Impoundments, (technical
guidance document, EPA, 7 /89). In accordance with the latter document, the recommended
design addresses the requirements of 40 CFR 264 and 265 Subparts G (closure and post~
closure), K (surface impoundments), and N (landfills). The final cover design would be
comprised of the following layers:
1.
2.
A vegetation \soil layer that is 18 inches thick, with a final slope of 3%. It is
O'Brien & Gere Engineers' understanding that the frost layer in North
Carolina is approximately 12" -18'', and thus such a soil layer would be
sufficient to protect the clay layer from the actions and effects of frost.
Vegetation will consist of locally adapted perennials with shallow root systems
that can thrive in low nutrient soils. The density of the plang will be such
that cover soil erosion will be no more than 2 tons/acre/year as measured by
the USDA Soil Loss Equation. This layer will be designed so that it requires
minimal maintenance and will be comprised of medium textured soils such as
loam. Refer to Drawing #2.
A low permeability compacted soil layer which is 18 inches thick with a
saturated hydraulic conductivity less than or equal to 1 x 10 ·7 cm/sec. The
layer wHI be free of clods, rocks, debris, cobbles, rubbish, roots, etc that would
increase the permeability or promote preferential water flow pathways. The
specifications will require that soil will be installed in no less than four 6" lifts
and will be compacted at a moisture content which is wet of optimum. A test
fill wi II be required using soil, equipment and procedures to confirm that
design specs are attainable.
3. Approved backfill from the bottom of the excavation up to the low
permeability soil layer.
Ot 11. ..... :, "0
a..r-£ w';+l-. ,..,,, .... J
c...1~-s.,,~
f/o.. ..
O'BRIEN & GERE
William F. Hamner, Ph.D.
August 4, 1992
Page 3
• •
You will note that this cap does not include a "drainage layer". Based on the results of
recent studies on similar projects, the technical advantages of the drainage layer have come
under question. Experience has suggested that the drainage layer may act as a "wick",
drawing moisture which sustains the vegetation layer, and drawing moisture from the clay
layer, which can cause desiccation cracking of the low permeability layer. We therefore
conclude that the drainage layer is not appropriate for CTI's facility.
Modifications to the Post-Closure Plan
Regarding comment (a) of the March 25 letter, on the length of post-closure care, 40 CFR
265.117(a)(l) provides that "care for each hazardous waste management unit ... must begin
after completion of closure of the unit and continue for 30 years after that date." Subsection
(2)(i) specifically provides, however, that the post-closure monitoring period may be reduced
by the Regional Administrator. He may (i) "shorten the post-closure care period applicable
... if he finds that the reduced period is sufficient to protect human health and the
environment ... ". The data which have already been submitted demonstrate that a shortened
post-closure care period is appropriate, in that the lagoon sludges have been removed, and
there is no ground water contamination in currently downgradient wells or in the stream.
We recommend that a three-year period be approved. Should ground water monitoring
results during this period indicate that additional post-closure care is necessary, then the
period may be extended at that time.
Regarding comment (b), on site security measures, per 40 CFR 265.117(b) as adopted in
15A NCAC 13A.0010, these regulations apply to facilities at which the land is used to
manage hazardous wastes. The hazardous waste at the CTI Charlotte facility has been
removed. Fencing currently surrounds the overall CTI property; this fence runs along the
northern, western and southern border of the former impoundment area (refer to drawing
#1). We propose the addition of fencing along the eastern boundary of the former
impoundment area, to completely enclose the subject area. Entrance to the property is
currently controlled by a dispatcher/nightwatchman who is present 24 hours a day, seven
days a week. Additional security measures that would apply to facilities managing hazardous
wastes would not apply to the Charlotte facility. As such, we request a waiver of the
requirements related to site security.
Regarding comment (c), on monitoring and maintenance activities for the former surface
impot1ndment area, in accordance with 40 CFR 265.US(c) as adopted in ISA NCAC
13A.0010, the vegetative cover will be maintained (cut) monthly dt1ring the growing season
for such vegetation, and reviewed monthly for maintenance needs in off-season months.
This maintenance will include the removal of vegetation suspected of threatening the
viability of the existing shallow-rooted plants. Deep-rooted plants or weeds that could
potentially disrupt the topsoil layer would also be removed. Monthly inspections of the
Ci8Rlf:N & hEFIE
•
William F. Hamner, Ph.D.
August 4, 1992
Page 4
•
condition of both the cap and the vegetation in the former impoundment area will be made.
The inspection will include a review of the items included on the attached updated
Inspection Log, such as cap integrity, signs of erosion, vegetative health/status, signs of
subsurface disturbance such as raised mounds or collapsing soils (e.g. due to burrowing
animals), water ponding and water runoff. Corrective measures will be taken, as
appropriate, to restore the covered area to the initial (design) conditions. Such corrective
measures may include regrading, in order to minimize percolation, removal of brush or
shrubs, and weed control. Should thinning of vegetation be observed that is indicative of
insect damage, an extermination program will be initiated, and overseeding will be done in
order to maintain a dense and uniform vegetative cover. Well inspection will also be
conducted monthly. The integrity of the well cover, lock and casing will be reviewed.
Damaged materials will be replaced and/or repaired, as appropriate, in order to maintain
the integrity and usefulness of the weli. Should a well used in subsequent monitoring be
discovered to be damaged beyond repair, the DEHNR will be notified as to an appropriate
replacement location, procedure, and schedule.
Regarding comment (d) related to a new survey plat and comment (e), on recording a
notice in the property deed, 40 CFR 265.119 requires a permanent notation on the facility's
deed that "the land has been used to manage hazardous waste; and [i]ts use is restricted
under 40 CFR Subpart G". Normally, such a recordation is required within 60 days after
certification of closure. However, this should be unnecessary at CTI's facility because all
hazardous waste at site has been removed. The regulatory requirement contemplates a
"dirty closure" with hazardous wastes in place; in CTI's case the closure is "dirty" solely
because of allegedly related ground water contamination at MW7 and MWS. Consequently,
CTI requests a waiver of this requirement, as well as that for the related survey plat for such
a property.
Regarding comment (f), requesting an updated post-closure cost estimate. This updated cost
estimate is presented in the attached revised Tables 13 and 14 (numbered to correspond
with the original tables in the 1991 Closure/Post Closure Plan). Pending your approval of
the above noted request for a 3-year monitoring period, please note that the tables still
reflect a 30-year monitoring period (as previously submitted).
0'8HIEN & GcRIO
TASK
1. Water Removal to CMUD
2. Exeavat1on
3. Stabll1l•tion
Mobilization
Stabili~at1on
4. Disposal
• TABLE 13
Cost Estimate for CTI
Charlotte, North Carolina
C1osure Plan/Post Closure Plan
Central Transport, Inc.
Charlotte, North Carolina
Revised July 28, 1992
Sludge and so11 s
Tr.ansport
10,773 tons total
S. Soil Sampling (Confirm Clean)
6. Backfill and Final Cover
7. Closure Certification
On-site Inspection
Report and Certification
8, Surveyor
9. Post Closure Care (per Table 14)
Subtot•l
Engineering/QA/QC (10%)
Subtotal
Administrative and Contingency (10%)
Total Estimated Project Cost
•
ESTIMATW COST
$4,410
completed
completed
completed
completed
completed
completed
$230,574
co1npleted
$15,750
$3, 150
$901,218
$1,155,102
$115,510
$1,V0,612
$127,061
$1,397,673
• •
Table 14
POST-CLOSURE COST ESTIMATE
CENTRAL TRANSPORT, INC.
Revised July 23, 1992
TASK UNIT COST # UNITS # TIMES/YEAR # YEARS COST
Well sampling
Labor (hourly basis) $62.00 24 2 30 $89 '280' 00
Direots
Plane fare $500.00 2 30 $30,000.00
Sampling equipment $75.00 2 30 $4, 500. 00
Analyses
EPA Meth. 624 (Volatile Organics) $250.00 7 2 30 $105,000.00
EPA Meth. 625 (Acid Ext/Base Neut) $500.00 7 2 30 $210,000.00
Total Lead and Chromium $235.00 7 2 30 $98, 700.00
Total Phenols $30.00 7 2 30 $12,600.00
Turbidity $15.00 7 2 30 $6,300.00
Total Organic Carbon $30.00 7 2 30 $12,600.00
Total Organic Halogen $70.00 7 2 30 $29,400.00
Mail/shipping $100.00 2 2 30 $12,000.00
Inspection & Recordkeeping
Labor (hourly basis} $62.00 4 12 30 $89,280.00
Personnel training
Labor (hourly basis) $72.00 24 $1.728.00
Directs
Plane fare $500.00 $500. 00
Directs $250.00 $250. 00
Project Management Costs
labor $72.00 16 2 30 $69,120.00
Directs $75.00 l 2 30 $4,500.00
Reporting
labor $72.DD 8 2 30 $34,560.00
Directs $50.00 1 2 30 $3,000.00
Amendments to Pl •n
Labor $72.00 40 30 $36.400.00
Directs $50.00 30 $1. 500. 00
TOTAL ESTIMATED POST-CLOSURE COSTS, FOR A THIRTY YEAR CLOSURE PERIOD $901,218.00
• •
POST CLOSURE MONTHLY INSPECTION LOG
CENTRAL TRANSPORT, INC.
Charlotte, North Carolina
Inspector:
Date:
Time: a. m.
STATUS
INSPECTION ITEM OK DEFICIENT
Fencing:
-intact
-undisturbed
Vegetative Cover:
-height of growth
(need for cutting)
-density and
uniformity of growt~
-thinning?
(insect impact)
-presence of
brush, shrubs or weeds
-surf ace
continuity
(sinks or mounds)
-surface integrity
(erosion, cracks, holes)
-water runoff
-other
observations
1
p. m.
COMMENTS/ACTION TAKEN
• •
POST CLOSURE MONTHLY INSPECTION LOG
CENTRAL TRANSPORT, INC.
Monitoring Wells:
MW-##:
-Protective Metal
Casing
-Lock
-Well Casing
-Well Cap
-Cement Pad
-Well Identif-
cation No.
-Refer. mark for
gw elevation
-Depth of well
-Turbidity of gw
samples
Continued
-Changes in gw flow into well
during well purging
-Changes in static gw elevation
MW-##:
-Protective Metal
Casing
-Lock
-Well casing
-Well Cap
-Cement Pad
-Well Identif-
cation No.
2
____ ft.
• •
POST CLOSURE SEMI-ANNUAL INSPECTION LOG
CENTRAL TRANSPORT, INC.
-Refer. mark for
gw elevation
-Depth of well
-Turbidity of gw
samples
Continued
-Changes in gw flow into well
during well purging
-Changes in static gw elevation
MW-##:
-Protective Metal
Casing
-Lock
-Well Casing
-Well Cap
-cement Pad
-Well Identif-
cation No.
-Refer. mark for
gw elevation
-Depth of well
-Turbidity of gw
samples
-Changes in gw flow into well
during well purging
-Changes in static gw elevation
3
____ ft.
____ ft.
• •
POST CLOSURE SEMI-ANNUAL INSPECTION LOG
CENTRAL TRANSPORT, INC.
MW-##:
-Protective Metal
Casing
-Lock
-Well Casing
-well Cap
-Cement Pad
-Well Identif-
cation No.
-Refer. mark for
gw elevation
-Depth of well
-Turbidity of gw
samples
Continued
-Changes in gw flow into well
during well purging
-Changes in static gw elevation
MW-##:
-Protective Metal
casing
-Lock
-Well Casing
-Well Cap
-cement Pad
-Well Identif-
cation No.
-Refer. mark for
gw elevation
4
----ft.
• •
POST CLOSURE SEMI-ANNUAL INSPECTION LOG
CENTRAL TRANSPORT, INC.
Continued
-Depth of well
-Turbidity of gw
samples
-Changes in gw flow into well
during well purging
-Changes in static gw elevation
MW-##:
-Protective Metal
Casing
-Lock
-Well Casing
-Well Cap
-cement Pad
-Well Identif-
cation No.
-Refer. mark for
gw elevation
-Depth of well
-Turbidity of gw
samples
-Changes in gw flow into well
during well purging
-Changes in static gw elevation
MW-##:
-Protective Metal
Casing
-Lock
-Well casing
5
___ ft.
____ ft.
• •
POST CLOSURE SEMI-ANNUAL INSPECTION LOG
-Well Cap
-cement Pad
-Well Identif-
cation No.
-Refer. mark for
gw elevation
-Depth of well
-Turbidity of gw
samples
CENTRAL TRANSPORT, INC.
Continued
-Changes in gw flow into well
during well purging
-Changes in static gw elevation
6
____ ft.
•
William F. Hamner, Ph.D., Head
Permitting Branch
July 15, 1992
Page 2
•
suhmitted to the State on March 2, 1991. This will permit CTI to submit a cap
configuration that is less complex than a traditional "RCRA" cap.
However, revisions to the Closure plan are required to address the possibility that
the lagoons will be closed as landfills. Four copies of a modification to the closure
plan specifying the design of the protective cover will be submitted no later than
August 5, 1992.
4. The State indicated no objection to backfilling, both in the May 1, 1992 meeting and
in subsequent conversations with representative of the State. Absent written
objections to the Risk Assessment documentation that the source has not been
adequately removed, CTI intends to commence backfilling of the site. We
respectfully request your prompt approval to our modified cap design.
Demonstration of source removal will permit CTI to request waivers to some of the
strict RCRA requirements for cap design and length of post closure monitoring
period.
5. A report describing the results of the ground water elevation measurements above
together with the results of the first round of sampling from three wells west of the
lagoons undertaken in connection with the Work Plan described in Item 2 will be
submitted to the State no later than August 14, 1992.
Please advise if the information contained in this letter requires additional clarification by
contacting the undersigned or Ms. Terry L. Norman of this office.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
~1~ ~ ....-::: h /"""' . r::f .,J
George if.iest, P.E.
Vice President
GBR;mjh
cc: G. Simpson
J. Doyle, Esquire
M. Fleischaker, Esquire
O'BRIEN & GERE
l.:.J.I _:u ::IC: 1 '.J; . ./_1 U. ·.:o. I: .• I '. 11. Id. Li. lli,!' ! CO'-;) K_. • •
March 2G, 1991
SUPPLEMP:N'rAL REGION IV RISK ASSESSMENT GUIDANCE
The following guidance has been prepared by the Region Iv risl<:
assessment staff to supplement and/or clarify the Risk
Assessment Guidance for Superfund (RAGS) manual, The purpo15e
of this guidance is to achieve consistency in the baseline risk
assessments (BRAs) prepa:i:-ed in this region by either
emphasizing or clarifying Region IV'$ position on important
issues. These issues are su.mmari2;ed in the following bullets 1
0
0
DATA EVAiiUATION
Unfiltered groundwater da.ta should be used to determine the
exposure point concentration.
Retain in the risk evaluat.ion, dat& with a qualifier
indicating uncertainty in conc:entration ("J" value).
Include these data along with the positive data which have
no qualifiers.
Tentatively identified compounds ( '.l'ICs) are to be dealt
with on a site/chemical 'speci1'.ic basis. If there is reason
to believe that a significant risk may be contributed by
TICs 1 then special analytical services (SAS) may be
required to prov.I.de data for t:he risk asseesment.
CON'l'AMXNANTS OF CONCERN
If a chemical is not detected in any media, assume that it
is not a site-related contaminant and do not include as a
site contaminant of concern. [Exception; If the sample
quantitation limit (SQL) for a substance is significantly
higher than the contract required quantitation limit
(CRQL), then specific consideration must be given to the
appropriateness of its deletion.]
Th;l!'! section should contain an init.ial table which
summarizes the paten~ site contaminants of concern.
This table should contain all contaminants which meet the
follow.ing criteria;
Contaminants detected in at least one CLP eample
Contaminants which are pi:esent at concentratione which
are si9nificantly higher than in blank samples (see
RAGS)
0
0
•
0
I I < -·"·-L .. /. ~·U U. ,.•. L.:.. I··'. I(. -· l.1J. J..1, • •
Surf ace soil contam1nat1bn should also be evaluated for the
inhalation exposure rout~. E:i1posure point concentratione
should be baaed on air monitorin9 data, if available, or on
modeled data, Lt; air data iii not available. Semi-volatilee
and inor9anice should be: assumed to be airbo:i:-ne via
suspended dust particles', The contribution from suspended
dust contamination will be dependent on the degree of site
vegetat.ion. The Region 'IV risk assessment staff should be
consulted for further guidance' in this area.
Volat.iles in groundwater should be evaluated for the
inhalation el!:posure rout;e as a result of water usage in the
home, i.e. cooking and showering.
The exposure frequency for the' swimming scenario contained
in Exhibit 6-12 of RAGS is low for th<;! southeast region.
Region IV reconunends a default exposure frequency of 45
days/year. ,
The averaging time (AT) .in the, intake equation for
noncarcinogens is the product of the years of exposure and
365 days/year. The AT tbr carcinogens is the product of
years in a lifetime (70)' and 365 days/year.
TOXlCITY ASSESSMENT
'l'he most recent toxicity data, 1.e. IRIS or HEAST 1 l'Jhauld
be used and referenced, as to the date of database access,
in the BRA •
Check that the exposure est.ima,tes and the toxicity values
are either both expressed as absorbed doses or both
expressed as intakes (administered doses). The exposure
estimates should represent intake levels for all exposure
routes with the exceptio,11 of the dermal route. The
toxicity values must be adjueted to evaluate the dermal
exposure route. (See R)\GS, Appendix A)· The toxicity
aseessment should contain a ta.ble summarizing the adjusted
toxicity values and the absorption rate used to make the
adjustment.
consult with Agency risk assessors on the use of the
Agency's biokinetic mode.l for lead exposure and other
procedures for evaluating lead! rl.sks.
!tEMEOIA'l'ION GOALS
The !'IRA should have a section whi.ch outl.ines the
remediation goal options' for the contaminants and media of
concern. This section should include both ARA.Rs and health
based cleanup go ale. Tl~e goals for the carcinogenic
contaminants of ccmcern shol,l!dl out;ine the tonc .. ntrations
that correspond with the 10~ , io-and 10-risk
' .
' . -'I. '.,'' • •
Reasonable Maximum E1posure
( i + 0.5 s 2 + .iJ:L)
UCL= e v'n-1
-x = 4.3
s = 1.24
H = 3.163
n = 16
o.s s 2 = o. 769
s H = 1.01
v'n·1
2·
( x + 0.5 s + s H ) = 6.079 --v.;:r
UCL= 437
Calculation
U-·I --·l.· .... :. l _1 • '··• • • I 1. 111.1
• • • ,
Sfall11Jt:a/ Tablel
Tilllle A12 Vlllu•• ot H, -• .. Ho• for Computing • Qnt=Sliad Upp.r $$% Conftd•ne• Ltm;1
on • Lognormal MHn
• .. • •• ,, II .. .. " "' •.Ht 1.1'~ .., .. ..... ,.Mt ,.,..,, '.1•• 1.m '.to1 ..... '·''O 0110 s.ig '·. '~"' I.NI 1.Ml '·'°' ""' '·''' ,,,,. '.1'7 .... • •• .... , '·'H 1.177 1.11'7 ...... , I.In ,_,., '. , .. 1 1.711 .... .. ,. . 1.u1 I .I I ..... MU ..... . .... '·'" t.111 ',.,,., .... ..... .. ,., .. ... 2.110 .. ,., . .... ..... '·''' '·''' 1 .•>D .... ,_ .. 1 •••• 7 a.in ..... '·''' ..... , ..... . .. , . ..... , .... , t.to t.llt ..... ..... 1-111 t.••• 1 .... ··''' l:~l I.Ill> ··-... , , ... , •.Oil '"~ 1 ,rto ,,,,. .... , MO! I. tt:t 1.011 .... ,, ·'' ··;;: ... '·'°' 1.1 .. .. ... '·'" a.110 ..... •·"' 1.00 1),0) •• I.Ito l,tOl 1-tll . ..... ..... t.\ll 1.1 .. r.101
1.u ,.,,I f.io1 .... a• ... ,. ··= ~.1a 1.tt• *·"" ,.Mt t ·'"' .... ..... 1,tto .. , .. ,,,01 '· 1.111 1.s11 J·"' ... , .a.ns
"71 II.II '·I'° ··m UM ••• 11 ..• , .. , .. .UI I.HO '·"' 1.00 *'·'' t. ,,. '·"" ..... •• HI ..... ..1 .. 1.111 l.llJ •.zn .... U."!' 1t ... , l.llt •.u1 •••• ..... "'" ..... •.a:r• .....
l.00 It.I) ,.~., ..... ··-'·''' u: ,_.., ..... ..... ,. ..... ,, .. .... ,, ,._,, ,, ,,... '·"' '·"' , .. ,, '·''' .... , t·"' .... Jt.11 ..... ,, . ., . ,,,,, ..... 1.UO .,.,n, 't'.O.t41 ••• 1, '"' .. so tl.t) 10, .. 'HI.to ~'"'" "·" ..... .... , ,_.,., '·"' ••• ,D
t.110 U.lt t) .• 1• lt.U "·" ''·'' 10.,, '·'" ..... '·'" '·'" .... ,., ... -, •t~., , ..... , ..... •••• 11 •• , , .... 10.:at .. ~~· .j ... \
J.00 •... , )t·.•) 11 ... 11,00 ,,,,. ..... ,, .. , 11.tJ ···r. 10.o!o
'·"" •ciu St~H .,.,, JG ••• ti.JI ,,. ·'' 1$ ••• 'l·" ... ; ,, ... .... "'" ··~" .... , 11.10 11;01 , .... , .. ,. .• 1 ,t) -t.b'J 11 .IS.
•O~ot 1,01J "~., JI.II ll.l4 ., ... It.II .. ... '' . .,, .,.,, ••.Hi
Soortt: ""'"' a....d. lt'5.
fta• ~hie it Yted it\ .$.i·Ol)n :1,.%,
T@i. AU Vllu" DI If. " lfo.o• tor Computing • Ornl-$1dtd Low•r 5% ~nfldtnee LllT'il
· on • 1.119norm11t M••n ·
•
• • J 1 .. " •• II " ,, . .. ..... . ,., .. . .... .., ·"' rioM "''••" ...... •I·= .. ...... . , .... _, .... ,
'·" ...... _, ·:r. .. , ... ,.. ......... , "''" ... ...... ••• ... i.pa. ., .. ,, .,,.,., .... •1.11• -1. ' ..,,..,. ... ,.,, -1 -ci; ·:·"' ., .... , -1.DI ...... .. ...... :::: • , ,.,,1: ·I~ t•1, .. 1't ... _,,, -··u: ... ·''' •1.ltl -··::: •l·t' _, ·": ....... " ........ .. , ..... • •• ...... ..,., _,. t1 I • -t.tli
I ··= ··-.. ,,..n ....... -··:: .,~''' •t.111 ·• ·"'' ···;r. -1.115" _,. ,.,,
•• "''"' •1-"' _,...., -·· ···= -1.Dt ....... -·· -1 _,,, .. , . , .. .... _, .... -·1 ·•.Ml . , ... -1 • -•.tM ···m "''·' . •1.T•7 ., . ,,, .... ., .... _, "'·:rt tot.Pt -··· -··-•l·J:' •1.)t;l' •1.?l!o ., •• 1, ... ........ ., ' .. ..•. -1.111 ., ... , ... ,., 111o1. I .,,,.. ., •• Jt ·t.•h ... ..... : ., .... 4•1,..-·'·"' ., ..... 1111.m -1.eitr ··; ., ·"' .. , .01 7 , ... ., .... ·•·m .. •• m •1 .. tt• ..., ... ) ...... -~ .... :1: M
...... , •J, ,., .... ., ... , •t,.. I ...... , ·1~•11 -1.1111 ...... -1.m . ..... , •:I' ,)41 I :::: -·--··: .. ,, .. , ...... ...... ·1·· .. • •• ·•·•11 ...... ,. •:t ·"''' -1.m, -·· ....... ····~ •t.U.• ..... . ..... . ..... •l.tto ..... ,l
' ••• ..... ... ; .,., .• -·--.._
•f~N ........ •l,•H• t'" .,,,., .... ::::=u· -1. . ..... , -1:m ;r:m ....... •f,IK ~·m • .IM1 .. ,, 710 ••• of. I ··•~•n . .. ,, • ._.M ..... •••• _..Ill .... .... ~ .... ···= 't"' :u:: -.... •l.'IA ...... -:m -'·''' ...... ... .,_: ... ' .. .... . .... , ..... , .... .,. """' ""'·""' •S.• ..
••• ..... : ... ffi ....... .... u 4.Mt .. , ... t ..... , .. -ti ••• , .. ,,., ...... ••• .,,.", ... •11111,lft .a.m ...Ill ...... ...... "'·U: ... IN .,,,,, ••• ....... .... . . .... " ...m ..... , ...... :f:ii: ••• ..f.KU' •7 .M:. ··: ... "l ..... ' ..... ,... ..... .... , .. ., .... ., ... ... .,, .... u ... .. .., ...... ....... ... 1.111 -r.u.e •I,,,. ... ... ,);!. ... SOJ .... 11
""''"' Allor i-. , .• ,,'
T1oh .w.., -"'..._ u.J.
----
• •
' Reaso~able Maximum Exeo~;ure Calculation
. '
Sample Data Set Lo~ Transformed
Chromium (mg/kg) Da a
25 3.22
13 2.56
41 3.71
67 4.20
10 2.30
230 . 5.44
1300 7.17
110 4.70
200 5.30
160 5.08
110 4.70
36 3.56
136 4.91
59 4.08
140 4.94
20 3.00
' .
U· I .. _,L1. .. 1..:..: I··-': _,_i U. :.:.. L. l . 1 /. 1.·.1. L' • • •
Reasonable Max/mµrt? Exp,osure Calculation
( i + 0.5 s 2 + .!.J::L)
UCL= e Vn-1
Where:
UCL= 95th upper confidence limit
on the ctrithmetic mean
e = constant: (natural log) -x = the mean of the transformed data
s = the standard deviation of the
transformed data
H = statistic (from the table)
n = sample size
04/30/92 15:35 U.S. E.P.A. -W.D. 005 c~rl(__ • •
March 2 Ei, l.991
SUPPLEMEN'.l.'AL REG10N IV RISK ASSESSMENT GUIDANCE
The following guidance has been prepared by the Region IV risk
assessment staff to supplement and/or clarify the Risk
Assessment Guidance for Super fund (RAGS) ntanual. The purpol!le
of this guidance is to achieve consistency in the baseline risk
assessments (BRAS) prepared in this region by either
emphasizing or clarifying Region IV's position on important
issues. These issues are sunm:1ari2:ed in the following bullets 1
•
DATA EVALUATION
Unfiltered groundwater da.ta should be used to determine the
exposu:ce point concentration.
Retain in ·tne risk evaluation, data with a qualifier
indicating uncertainty in conc:entration ("J" value).
Include these data a1ong with the positive data which have
no qualifiers.
Tentatively identified compounds (TICs) are to be dealt
with on a site/chemical :specif'ic basis, If there is reason
to believe that a significant risk may be contributed by
TICs 1 then special analytical services (SAS) m1:1y he
required to provide data. fo:c the risk assessment.
CONTAMINANTS OF CONC!'=RN
If a chemical is not detected in any media, assume that it
is not a site-rel&ted contaminant and do not include as a
site contaminant of concern. [Exception; If the sample
quantitation limit (SQL} for tl substance is significantly
higher than the contract requJlred quantitation limit
(CRQL), then specific consideration must be given to the
appropriateness of its deletion.]
This section should contain an init.ial table which
summarizes the potenUU site contaminants of concern.
This table should contain all contaminants which meet the
followin9 criteria;
Contaminants detected in at least one CLl? sample
Contaminants which.1:1re present at concentrations which
are significantly higher than in blank samples (see
RAGS)
•
•
04/30/'32 L5:36 U.S. E.P.R. -W.D. 007 • •
Surface soil contamination $hould also be evaluated for the
inhalation exposure route. Ex~osure point concentrations
should be based cm air monitoring ctata, if available, or on
modeled data, if air data is not available. Semi-volatiles
and inorganics should be' assumed to be airborne via
suspended duet particles. The contribut;J.on from suspende<:I
dust contamination w;J.11 be dependent on the degree of site
ve9etation. The Re9ion IV risk assessment sta.ff should be
consulted for further guidance' in this &rea .
Volatiles in groundwater should be evaluated for the
inhalation exposure route as a. result of water usage in the
home, i.e. cooking and showering.
The exposure frequency for the' 11wimming scenaz:io contained
in Exhibit 6-12 of RAGS ;is low for the southeast region.
Region IV recommends a default exposure frequency of 45
days/year.
The averaging time (AT) in the' intake equation for
noncarcinogens is the product of the years of expo11ure and
365 days/year. The AT :for carcinogens is the product of
years in a lifetlme (70) and 365 days/year.
TOXICITY ASSESSMENT
'l'he most recent toxicity data, i.e. IRIS or HEAST, 11hould
be used and referenced, as to the date of database acce11s,
in the BRA.
Check that the exposure est.ima.tes and the toxicity values
are either both expre11sed as absorbed doae11 or both
expressed as intakes ( adm;J.n;J.st.ered doses) • The expo11ure
estimates should represent intake levels for all exposure
routes with the exception of the dermal route. The
toxicity values must be <i.djusted to evaluate the derma.l
exposure ;coute. (See RAGS, Appendix A). The toxicity
aaseesment should contai'n a ta,ble summarizing-the adjusted
toxicity values and the absorption rate used to make the
adjustment .
Consult with Agency risk assessors on the use of the
Agency's biokinetic model for lead expo1:1ure and other
procedures for evaluating le&d risks.
REMEDIATION GOALS
The BRA should have a section which outlines the
remediation goal options; for the contaminants and media of
concern. This section should include both ARARs and health
based cleanup <;Joals. The goals for the carcinogenJ.c
contaminants of concern 'shol'!dl out;;J.ne the goncentrations
that correspond with the. 10~ , 10-and io-risk
f
04/30/92 15:37 U.S. E.P.A. -W.D. 008 • •
levels, For noncarcino9ens 1 the concentrations that
correspond with HI value'3 of 1 and 10 should be tabulated.
ECOLOGICAL ASSESSMENTS
The BRA for all NPL si:t.e,s shou,ld include em ecological
assessment. Agency gui.di'mce for conducting thi11 assessment
is currently limited. However, RAGS, Volume II 11hould be
followed. Region IV has establi11hed a technical advisory
group (ETAG) for supporting RFMs on ecological i1:H1ues at
NPL sites and will be used to evaluate contractor
submissions.
04/30/92 15:38 U.S. E.P.A. -W.D. • •
Reasonable Maximurq E~posure
- 2 c x + 0.5 s + .l..J:L)
UCL= e Vn-1
-x = 4.3
s = 1.24
H = 3.163
n = 16
0.5 s 2 = o .. 7651
5 H = 1.01
v'n-1
2 ( x + 0.5 s + s H ) = 6.079 --vr.;:r
UCL= 437
009
Ca/cu/at/on
04/3(;)/92 15:38 u. ~3. E.P. A. -W. D. 010
• • • ,
St•t11ticat Ttblfls
Tillll• A12 Vatun Of H, •• .. Ho• lot COll'lputlng I gnt=Slll<Od Upp.r Mi~ COnnd•ne• Llr"'I
on a Lo91'1ormal M•an
• .. • .. " .. " 11 •• IOI
D.10 •·''° 2.01, ..... t.to: 1. ,.,~ ',., .. 1 ,.,Ii , • 't'Ol ··r.: '·''"' o.io •·m "'" I.HI ,_ .. , ,_ .. , ..... ;~111 '·''t '" ,, '·''7 '·"" ••• .a.toi 1.1;.i '.tff o.m .... z I.Ill ,_,., '-,,, 1.m ,,,,. .. ,.. ,, .. , 1.m ..... I.II• ..... ..... '·IN , .111 ,,.,.,,., .... '·"" .... f ,,. .. i.110 t. ••1 I.OM ..... , f.,. 1.11• 1 .•le .... ., .• ~ a.111 a.an ..... ,_.,, .. ,.~ , .... 1:.11110 . .... 1.••1 .... ••• 10 l.M2 ..... 1 .. 111 1.•1• ..... !1 ,,, I .~OJ l.W ··-.... , ... , •.tiii2 '·'" MIO !· ... l.ftil;) lf)O"I' '·'°' J. ,,, 2.CU '·" ,, ·'' ... .,. '·"'~ MOI "" .. ... 1.m a.tlO '·"' t.H1
1.00 1).0) q .. ,,., .. l.•OI :a .. 111 ,,,. .. '·"' l.ftll 1.111t t .i:o~
1, II , •• aJ .... ; tj,.tii• 1 •• , .. ·~·· a.1~ '·"I '·"' ..... i .... , .... tt.l!b ""' 1.1 .. ,,101 MK •• ,11 "" S,677 ~ .•. , ,"1)
; ·'' 11.•:t '·!" ..... ..... •1•lJ ..• , ··''' .. .. ,, ..... !·"' .... 11.11t-t .• , ,,,.,. J.IH .... , ..... .. ,., ... ,, ti.Ill ., .. .... "·'I' ,, ... , I.lit •.w1 '·"" ...... .,,,,, . .... •.ai• ), 20
l,OD lt.J) 1) .. ,, .;"'111, ,,_ t I .. ,, t,J'fO .... , . .... . ... , ..... .... ·~·'"' ,.~1'7 ,, '"' t.nt '·"' ·-... ,, '·'" 1.111 •·m .... ll.I' ... ~ .. ,,,,. ,,,,. ••••• l,UO ?.nt t.01• '·'"' ..... .... ..... IM• "t•.IO 't ·"' ;o.u "'" ..... '·'Iii '" ,,., ...ltD
lit~ ..... ), • 1i ,, .. , "·" ,,,1, ,o,ri '"" ..... ,I.,, J,tn
'·" '*·'' t7~., 1t.U ,,,,, , ..• ,, .. , ,,," 10.•• ...... ··~' .... ,,,lS II',•, ll.t< 11.00 ''·" 14.to 't),.~1 ,t.Ot ..... •Ml
''" ••• f. St;.o. 14,20 IUI 11.n ,,.,. . .. ,, 1)1 ?• 'tl.l' \LIU,
'·" m.J •1;.61 t•.•• 11,IO ll;OI .•. ' ,,.,. 'tl.•) ~• .. QI 11.l'!o
,O.DO ••Q.J "~l' u.11 ..... n.11 II.II ..... ,,. . ,, ,,,,, , •• J.
.SO..IU: After Lond, 1!1'1$.
nu. aable it uted m $.ctii:rl'I jl3.:.
Tab .. A1ll \111un DI H. • Ho,~ lor Computing• On.-Sld~ Low•• 5% Conn~•"•• Lim;1
Ol1 • l.ognD""•' M•a~
• • • •• .. •• II " •• ...
'·'' <1.,'Ula ..... .. 1.nt •t •• .,.,.n . , .... .. .... ..,v .... _,,...., .. ,, .. ~ .... 111~• ···::: "'·'" .... t.J) "''•"' ., .... ... ,,..,,.. ,.,,fM ., ,JJJ .. 1 • ..-; .... ····" ••• ..,,n, ..,~.,, ·•·tu .,.w ..,.WT 111t.DI .,,,,. .,,.,. . :::: ., ,,,., • , :::t j•1 .... ;; ., .• ,, ·'·w .. , .. ,, .,,,,. ., . .,. ., ..... , _, .6': ., ..... •• .. ..... ., ..... .., . .. ..... , . ..,., ...... ...,, ... ,, _,_ .. }
••• . , .... ::1 i11 ... ...... ., .. ,, ···m .., ... a .. ,t. ..,~ .. ~ ·\·''' .. ,. ....... •t•..Mii ... .. "'·U: .,, .. , ..... , ., .... ·•.m .; ·'·· .... ......... , ., "':t: .. , .... ••• ... ..... ..., ,.,,. .., .'t'•1 •L ,,, .... ...... ... "' • •t,QJ •1.IM .... ···;:· .,.,.,, •1.711 11\,lU1 ... ., .... : •I . .,, ...... ··~ .. .. ... , "''t"' •1. ,, ·•·"" ., •• J, •t.th
•••
.,_ ...... .. ,~..,. ., ·"' .. .. = .,.,... .. , ... " ··; •to9111tt -t .01 7 ... ....... ···m .. ,.m ... , ...... .... . ..... . ...... :I: M ..... ~ •J,, .. .... ..... ,. ••• • .. , ·"' ..,~,,, "'·"" ... ., . . ..... ., ·"' •1,,.. I u: ··:m .... .. , .. ,, "'·'" ... :1 •*·'"" •l,UO o«.11• "'·''' •).:U• .... • •• ....... •I.IA ..... ' .. , .... . ..... ·1~• ii',,, • .... ,, .... ·1~· ""·:a •1111-...... ··-.,,,.. ........ ., .• ,. -;.;., w),)111~ ... ::·· .... ·•l.Mf . .... :}:rt: ••••• •:,IK ....... . ..... ...,! 710 .... .n>: ... "lolll' . .. ,,; .... M ...... . ..... -t.HD ... m ;::: ....... ···= ..... :::;: .... ·•.m ..,~ ... ~"'" ..... ,. ... w <fMI ., .. ....... ........ ... ..• , ... .,. ..,.,, .... ... , •S.,1 .. .... ..... ···m ~ ...... """'·"" ..... , ,...,.,, ..., .. ~ .... , :::m ... -.... .... -... . ...... ... ,,. ..... ...w ... .... ...Jrt •1.1U._ .... ....... , .... ' '"···· .. .• ....... ... NO .. ,,,, ...... •7.Mt •7.M< .... "'·"'· .... ' ...... *'·"2 ... ,., •I.Ill .. , ... ...... ...IOI ... ,,u ..... .. .., "·'" '°'tMO .,_, .. ., .tw •l.l'IO .. .... ... ,~ ... 101 ..... ,.
''"""' Allot "-'· 19'5' nu. -lo -.. ...._ 1'.l.
·-·--·····-·· ,.·-·---···----------------.
' . . 04./30/92 15: 39 U.S. E.P.A. -k.D. 012 • •
Reasonable Maximum Exp,osurs Calculation
(!i+ 0.5 s 2 + § H)
UCL= e vn-1
Where:
UCL = 95th upper confidence limit
on the arithmetic mean
e = constant (natural log) -x = the me.an of the transformed data
s = the standard deviation of the
transformed data
H = statistic (from the table)
n = sample size
J
William F. Hamner, Ph.D.
March 31, 1992
Page 2
• •
If you have any questions on this matter, please do not hesitate to contact me.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
--<1w 2. ?·r·
George ~est, P.E.
Vice President
GBR:mjh
cc: G. Honbarrier
J. Doyle, Esquire
M. Fleischaker, Esquire
G. Simpson
J. Carter
R. Glaser
T. Norman
S. Mogilnicki
O'BRIEN & GERE
Mr. Iawrence Wellington
March 25, 1992
Page 2
• •
b) Provide a description of security measures to be irrq;>lemented during post
closure in a=ordance with 40 CFR 265.117(b) as adopted in 15A NC'AC 13A
,0010.
c) l?rovide a description of the planned IOC>nitor.ing activities and planned
maintenance activities to be irrq;>lemented to ensure the integrity of the
protective cover and of the IOC>nitoring wells in accordance with 40 CFR
265,llS(c) as adopted in 15A NCAC 13A .0010. Include a description of
possible problems that may oc.cur with the protective cover and IOC>nitor.ing
wells and the corrective maintenance measures to be taken in the event that
such problems oc.cur. These problems may include but are not limited to:
damaged or degraded wells, damaged protective caps or casings, damaged
concrete collars, and =ack.ing or settling of the cap, etc. Provide a copy
of the updated inspection log which includes specific items that must be
inspected.
d) Provide a copy of the survey plat in accordance with 40 CFR 265.117(b) as
adopted in 15A NC'AC 13A .0010.
e) Provide a notice to the local land zoning authority and notice in deed to
property in accordance with 40 CFR 265.119 as adopted in 15A NCAC 13A
.0010.
f) Provide an updated post-closure cost estimate. CTI cannot use the present
worth method to develop the cost estimate.
Four (4) copies of a IOC>dification to the closure plan specifying the design of the
protective cover and four (4) copies of a revision to the post closure plan must be
subnitted to this office within thirty (30) days of receipt of this letter. If you
have any questions please call Katherine O'Neal at [phone].
sincerely, . ~ ~~'Ph.D., Hr ~:~Branch
Hazardous Waste Section
WFH/KID/119-120
cc: G. Alan Farmer, US EPA, Region IV
James A. Carter
Robert Glaser
Judy Bullock
Msrc L. Fleischaker
John Doyle, Jr.
Gary L. Honbarrier
John Gilson
Jesse Wells
Douglas Roberts
Katherine L. O'Neal
' ' •
Jerome H. Rhodes, Chief
March 2, 1992
Page 2
•
O'Brien & Gere would be available to meet with the appropriate parties within your office
to discuss the contents and conclusions of this document .if you deem it necessary. If
additiona.1 information or clarification is required please do not hesitate to contact the
undersigned, Ms. Terry L. Norman or Ms. Ruth A. Hartcorn of this office.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
/,.1 --0 . t;:.tl-~Rest, P.E.
Vice President
RAH:TLN :GBR:mjh
Enclosures
O'BRIEN & GERE
•
William F. Hamner, Ph. D.
January 14, 1992
Page 2
•
Please do not hesitate to contact the undersigned or Ms. Terry L. Norman of this office if
you require additional information or assistance.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
~1 ?>-~+ G~Rest, P.E.
Vice President
GBR:TLN:mjh
cc: G. Simpson
L. Wellington
J. Doyle, Esquire
M. Fleischaker, Esquire
J. Rhodes
J. Carter
K. O'Neal
T. Norman
O'BHll'N & c;rn!'
James Carter
December 23, 1991
Page 2
• •
The attached pages F-1 through F-l2 indicate that the closure plan does not require the
soils to be stabilized unless necessary to meet the requirements of the receiving disposal
facility. Your attention is directed to the marked sentences contained on pages F-2, F-4, F-
8, F-11, and F-12. Please advise promptly if you reach a different conclusion after reviewing
the attached pages, as Central Transport's contractor will be returning to the site on
December 26, 1991, to complete the soil removal.
Please advise if you require additional information or clarification. The writer can be
reached at [phone] on Monday, December 23 and until 11:30 a.m. on Tuesday,
December 24, 1991.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
l~LN~
Terry L. Norman
Project Engineer
TLN:mjh
cc: G. Simpson
J. Doyle, Esquire
G. Rest, P.E.
CH1RltN & CEHEo
• •
January 4. 1991
cement based processes are collllllonly used in
stabilization. cernentitious processes add cement
and water (if not already present) to the waste.
Lime based or pozzolanic processes involve
siliceous and aluminosilicate materials, which do
not display cementing action alone, but form
cementitious substances when combined with lime or
cement. In both cement and pozzolanic processes
additives are sometimes combined with the
stabilization compounds to improve the
characteristics of the final product.
The primary mechanisms involved in the
stabilization process is rnicroencapsulation.
Microencapsulation is a process in which the
contaminants are mechanically locked into the
stabilized matrix. Contaminant loss is limited by
decreasing surface area exposed and isolating the
contaminants from environmental influences
(EPA/625/6-89/022). In addition to simple
encapsulation of the waste, chemical reactions
between the waste and stabilizing agent can also
reduce the concentration of wastes. In a recent
study (Connors and L: 1990) leachability of
F-5
-'.3_ = :: ',' r·,
• •
January 4, 1991
determine the presence of free liquids.
unconfined compression tests were performed
according to ASTM D 2166. Stress and strain
measurements were recorded for each sample. A TCLP
test was performed on a sample that had been
stabilized using Portland Cement to assess the
reduction in leachability provided by the process.
Table 11 summarizes the results of this analysis.
Based on visual observations and physical and
chemical analyses, the addition of Portland Cement,
cement kiln dust or combinations of these materials
are viable remedial alternatives for the treatment
of sludge at CTI because they provide the highest
ranges of unconfined compression strengths and
reduction in leachability potential to near
detection limits (Appendix D).
F-lbC2lbCiiil on-Site stabilization
Portland cement and/or cement kiln dust, or an
approved equivalent, will be used on-site to
stabilize the sludges. The sludge will be mixed to
produce a homogeneous mixture. The lagoons are out
F-8
\_
• •
.;rariuaa 4, 19 91
of service; therefore, the measured volume in April
198 8 of approximately 5, 200 cubic yards is not
expected to change.
F-lb(2\bCiv) Sampling and Testing Program
The frequency of sampling shall be one discrete
sample per ·1 1 000 cubic yards of sludge as
determined using the methods described in USEPA S~-
846 "Test Methods for Evaluating Solid Waste." The
sample will be tested for leachability (TCLP) and
free liquids (Paint Filter Test), and unconfined
compressive strength (ASTM D 2166).
F-lb(2)c Removal of Structures
The concrete walls and sluiceways of lagoon 1 will be
excavated and disposed of properly. contaminated
structures will be stockpiled in a manner that will
prevent a release into the environment using roll-off
boxes or other suitable means. Prior to disposal the
concrete will be decontaminated using similar procedures
as outlined in Section F-lb(2) f(iii) (page 44),
F-lb(2Jd Off-Site Disposal
Once the sludge has been stabilized, cured, and all
testing has been completed, the stabilized sludge will be
F-9
. , .. ', • ------------------
O'BRIEN Ei GERE
November 12, 1991
William F. Hamner, Ph.D., Head
Permitting Branch
Hazardous Waste Section
State of North Carolina
• Ce"+.l,.J Tr<A.llS/,,,..f
p.JC/) O'-/ b /'lfl 5l/O
®
RECEIVED
Nov 1 s t991
/IJ!!A.RDO"" " Vv •IASr~ n~c•1r.. ... "'-' "'IJ
Department of Environment, Health, and Natural Resources
Division of Solid Waste Management
P.O. Box 27687
Raleigh, NC 27611-7687
Dear Dr. Hamner:
Re: Statistical Analysis of Unfiltered Ground
Water Samples -Charlotte, NC
File: 5178.002 #3
The purpose of this letter is to provide the results of the statistical analysis performed on
the unfiltered metal samples from upgradient and downgradient ground water wells around
the lagoons at the Charlotte facility. The statistical analysis was performed on the eight
RCRA metals as specified in our letter dated May 22, 1991 to Jerome Rhodes of the
Hazardous Waste Section of the North Carolina Department of Health, Environment and
Natural Resources. In the July 26, 1991 correspondence from James A. Carter, the State
of North Carolina informed CTI that it would not require this statistical analysis until after
soil samples have been taken to confirm a clean closure, however, this information may be
useful in evaluating the present condition of the lagoons, and provides the State with an
opportunity to review the methodology used in the analysis.
Introduction
Ground water monitoring regulations and related guidance documents were reviewed to
confirm the proper statistical method to be used. The primary reference used in the
statistical analysis was "Statistical Analysis of Ground-Water Monitoring Data at RCRA
Facilities -Interim Final Guidance" (USEPA, February 1989). According to this document,
the selection of the type of analysis performed is primarily dependent on the level of
monitoring a regulated unit is currently in. In both its April 19, 1991 and July 26, 1991
correspondence, the State of North Carolina specifically requested "a comparison of
O'Brien & (.Jore t ngincnrs, Inc .. an O'Brien & Gere Limited Cornpany
6201 C()rporale Dr./ Suite 1000 I Londover, MD 20785 I (:301) 7:11-5622 FAX (301) !\H-4?3'1
and offices in ma;or Us. cities
, •
William F. Hamner, Ph.D.
November 12, 1991
Page 2
•
background levels to the highest levels detected downgradient". 40 CFR Part 264 and 265
define this type of monitoring as detection monitoring, that is monitoring to determine if a
release of contaminants has occurred.
Once the type of monitoring has been determined, the second factor in determining the type
of statistical analysis to be performed is the number of observations below detection limits.
Because the number of observations below detection limits varied in the different
constituents analyzed, the constituents were placed into two separate groups and two
different analyses were performed.
Comoosition of Data Set -Wells and Sampline Dates
The upgradient bedrock wells were considered to be MW-6, MW-9, and MW-10. The
downgradient bedrock wells were considered to be MW-7, MW-8 and MW-11. These wells
were used in the analysis because they contained the most complete and reliable data set.
Ground water quality data from MW-12 was not used because of elevated pH levels
observed in the well cause the data to be suspect. Ground water quality data from MW-14
was not used because the well appears to be located at a flow divide, and is not considered
to be either upgradient or down gradient; in addition only three sets of data have been
collected from this well. An equal number of rounds of data from all wells included in the
analysis is desired, in order not to weight one well any more or less than the others.
Ground water quality data from MW-13 and MW-16 were not used because only two rounds
of samples have been collected form these wells.
Complete sampling rounds were performed on unfiltered ground water samples in 10/89,
6/90, 12/90, 3/91, and 6/91. All of these sampling rounds will be used in the analysis as
the quarterly frequency of sampling will reduce the effects of seasonal variations. Table 1
summarizes the sampling results, and the percentage of observations above detection limits
for each constituent.
Analysis Methods
Figure 1 is a flow chart taken from chapter 5 of the reference document showing the
rational for selection of the two methods used. For constituents where more than 50% of
the observations were below detection limits, but at least 10% of the observations were
above detection limits, a test of proportions was performed (arsenic, cadmium, silver and
mercury). For constituents where more than 50% of the observations were above detection
limits, a non-parametric one way analysis of variance (ANOVA) was performed (barium,
chromium, and lead). The non-parametric ANOVA was used because the proportion of
0'8HlcN & GERE
• •
William F. Hamner, Ph.D.
November 12, 1991
Page 3
•
non-detects was greater than 15% and Figure 1 indicates that a non-parametric analysis
should be performed in this case. Selenium was not detected in either the upgradient or
downgradient wells.
Test of Proportions
The test of proportions determines whether the proportionate number of observations above
detections limits in the downgradient wells differ significantly from the proportionate
number of observations above detection limits in the upgradient wells. A significant
difference, defined as greater than the 97.5 percentile from the standard curve, indicates
statistical evidence of contamination. The procedure and results of the test of proportions
is given in Table 2. Table 2 indicates that there is no statistical increase in arsenic,
cadmium, silver, or mercury in downgradient wells. It should be noted that one of the
required criteria for a constituent to be analyzed using the test of proportions is that at least
5 observations were above detection limits. This criteria is met for all the constituents
except mercury, where only 3 observations were made above detection limits. For
consistency, and because no other methods were presented for this case in the reference
document, mercury was analyzed using the test of proportions.
One-Way Non-Parametric Analysis of Variance
The purpose of the one-way non-parametric ANOVA is to test the null hypothesis that all
wells (or groups of wells) around "regulated units" have the same median concentration of
a hazardous constituent. The procedure used in the one-way non-parametric ANOV A is
called the Kruskal-Wallis test. The procedure and results of the Kruskal-Wallis test is
summarized on Table 3. Table 3 shows that the null hypothesis holds for barium,
chromium, and lead. Suggesting there is no statistical evidence that barium, chromium or
lead contamination is present.
Conclusions
The results of the analyses performed on the unfiltered ground water samples from the
lagoons at the Charlotte facility indicate that there is no statistically significant evidence of
a release from the lagoons.
U'HHIEN & [;ell!'
,. •
William F. Hamner, Ph.D.
November 12, 1991
Page 4
•
Please advise if you require additional information or clarification.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
Attachments
GBR:TLN:SPS:mjh
cc: J. Doyle, Esquire
M. Fleischaker, Esquire
J. Rhodes
J. Carter
K. O'Neal
G. Rest
T. Norman
S. Mogilnicki
S. Shach
(J'IJRIFN f, c;rnF
•
William F. Hamner, Ph.D., Head
October 28, 1991
Page 2
•
Please do not hesitate to contact the undersigned or Ms. Terry L. Norman of this office if
you require additional information or assistance.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC .
.../'--/ 75 . .:::> + -~Rest,PT
Vice President
GBR:SPS:mjh
cc: R. Glaser
G. Simpson
J. Doyle, Esquire
M. Fleischaker, Esquire
J. Rhodes
J. Carter
K. O'Neal
T. Norman
S. Shach
0 BRIEN & GERE
PARAMETER I
---------Arsenic
Bari. ca"'1
C.hrom
lead
Silver
Mer-cury
Selenimi
PARAMETER
Arsenic
Bari LAil
c.am.illTI
Ch rorni llll
Lead
Sil vei
Mercury
Seler.
1111-6
10/89 06/90 12/90 03/91 06/91
--------------------------------------------0.01 o.or. <0.01 <0.01 <0.01
2.09 0.4 <0.1 <0.1 <0.1
<0.01 <0.01 0.02 0.01 <0.01
0.41 0.08 0.01 0.01 0.07
0.26 0.08 0.03 <0.02 <0.02
<0.01 0.09 <0.01 0.01 <0.01
<0.0005 <0.0005 <0.0005 <0.0005 <0.0005
<0.01 <0.01 <0.01 <0.01 <0.01
MW-7
10/89 06/90 12/90 03/91 06/91
Table 1
Ground Wster Results and Ho. of Observations Above Detection limits
Statistical Analysis of RCRA Metals on Unfiltered Ground Yater S~les
Central Transport, lnC~-
charlotteJ North Carolina
UPGRADIE~T WELLS
MW-9 111/-10
10/89 06/90 12/90 03/91 06/91 10/89 06/90 12/90 03/91 06/91
-----------------------------------------------------------------------------------------<0.01 <0.01 <0.01 <0.01 <0.01 0.04 .<0.01 <0.01 <0.01 <0.01
0.28 G.1 <0.1 <0.1 <0.1 0.48 0.16 <O .1 <0.1 <0.1
0.06 <0.01 0.02 <0.01 <0.01 <0.01 <0.01 0.01 <0.01 <0.01
0.06 <0.01 0.02 <0.01 0.02 0.17 0.04 0.02 <0.01 <0.01
<0.02 <0.02 <0.02 <0.02 <0.02 0.15 0.02 0.03 <0.02 0.04
<0.01 0.07 <0.01 <0.01 <0.01 <0.01 0.04 <0.01 <0.01 <0.01 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <O. 0005 <0.0005
<0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
00\l!IGRADIENT MELLS
MW-8 NW-11 10/89 06/90 12/90 03/91 06/91 10/89 06/90 12/90 03/91 06/91
No. of observations
above detection limits
Upgradient (Pu)
-------------------------3/15 6{15
5(15
11/15
6/15
4/15
0115
0115
No. of observations
above detection limits
Upgradi ent (Pd)
----------------------------------------------------------------------------------------------------------------------------------------------------------------0 .1 0.13 <0.01 <0.01 <0.01 0.04 <0.01 <0.01
1.14 0.87 <0.1 0.12 0.82 2. 11 o. 1 0.56
<0.01 <O.Ot 0.02 0.01 <0.01 <0.01 <0.01 0.01
0.58 0.21 0.08 0.04 <0.01 2.65 <0.01 1.8
1.45 0.32 0.17 0.08 0.05 0.06 <0.02 <0.02
<0.01 0.15 <0.01 <0.01 <0.01 <0.01 0.08 <0.01
<0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 0.003 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
<0.01 <0.01 <0.01 <0.01 <0.01 0.12 <O. t o. 19 0.37 0.65
0.02 <0.01 <0.01 <0.01 0.01
1.28 0.02 <0.01 0. 16 0.2 <0.02 <0.02 <0.02 0.04 0.1
<0.01 <0.01 <0.01 0.04 <0.1
0.004 0.0028 <0.0005 <0.0005 <0.0005
<0.01 <0.01 <0.01 <0.01 <0.01
<0.01 0.2
0.01
0.04 <0.02
<0.1
<0.0005
<0.01
<0.01 3/15 <0.1 12/15
0.01 7/15
0.78 12/15
0.03 9/15
<O .1 3/15
<0.0005 3/15
<0.01 0/15
Total Observations
PARAMETER I above dete<tion limits
Arsenic
BariL..m
C.adni Lill
ChrooiL111
Lead
Silver
Mercury
SeleniUTI
No. X
6/30
18/30
12/30 23/30
15/30
7/30 3/30
0/30
20
60
40
77
50
23 10
0
Table 2
Method of Proportlons
Statistical Analysis of RCRA Metals on Unfiltered Ground ~ater S~les
Central Transport, Inc ••
Charlotte, North Carolina
x = rn.nber of upgrad\ent wells in which constituent was detected
y = rtUJbe r of downgradi ent we l ls in which cons ti t uent was de tee t ed n =total nuri>er of upgradient wells analyzed
m = total nt.llber of downgradient wetls analyzed
Pu= x/n =proportion of observations above detection limits in upgradient wells
• y /m = proper t ion of observations above detection l i mi ts in downgrod i ent we l ls
SD = ([(x + y)/(n + m)l C1 • Cx + yl/(n + m)J 11/n + 1/mJ l ~1/2 = standard error of the difference in proportions
2 = CPU -Pdl/SD
The calculated value of z is corrpared to 97.Sth percentile form the standard normal distribution, 1.96~
Jf the absolute value of Z exceeds 1.96m this provides statistically significant evidence at the S% significance tevel
tnat the proportion of downgradient wells samples where the cOfllJ'CUf"ld was detected exceeds the proportion of upgradient wells
where the constituent was detected. This would be interpreted as evidence ofcontamination.
wo. ~f observations No~ of observations Standard Error Z Statistic ls absolute value of z 1statistical Evidence Qf
PARAMETER above detection limits above detection limits (Sll) (Zl greater than 1.961 Contamination
~·i~--Upgradient (Pu) Upgradient (Pd) -----·---·-----·-----·------······---------·-···-·-····---------------------------------------------------------------------------3/15 3/15 0. 146 0 no no
C:ad'nitm 5/15 7115 0.179 -0.949 no no Silver 4115 3/15 0.167 -0.18 no no
Mercury 0/15 3/15 0.109 1.82 no no
Page 1 of 2
K = the nurber of observatiOJls in eac~ group
ni = the n.tJJber of observations in the ith group
N = total lllllber of all observations
Ri = SUTI of the ranks of the ith group
K
Table 3
One ~ay Non·Parametric Af'lalysis of Varlance Statistical Analysis of RCRA Metals on Unfiltered Gr~ Water Sanples
Central Transport, Inc ..
Ch-artotte, North Carolina
H = {[12/N{N + 1)) [SIGMA {RiA2/NiJJJ -3CN + 1) =the KNJskal-Yallis statistic
i~
1. Rank all N observations of the gr"'-"8 fr<Xll the least to the greatest
As a convention, the upgradient well observations will all be put lnto one gro..,.::i.
2* Add the ranks of the observations in each group~
3. COIJl>Ute the Kruska!-Yellis Statistic
~re the calculated value of H to the tabulated chi-squared value with CK·1J degrees of freedom
~ Table 1 from Appendix B of the referr.ce docunent, with 3 clegrees of freedom at the S~ significance level this value equals 9.348.
S. If the c""""ted value exceeds the chi-squared value, reject the null hypothesis.
~OTE: Jn the case of observations at tne same value, determine the ranks the tied observatiO!'ls would have received' if they
had been slightly dlfferent from eacti other, but still in the same place with respect to the other observatiQns,
Add these ranks and divide by the nurber of observations tied to get an average rank.
fOi ex~le~ if there are three observations tied at a.z, that would of had a rank of 4, 5 and 6 if they had been slightly dffferent
The three observations would all be given tne rank of 5, the result of averaging 4,5, and 6.
•
RESULTS OF ONE-WAY NOii-PARAMETRiC Al«lVA
The concentration of each sa~te is given on the left and the rank of that sarq::ile is given in parenthesis
BARI UH
N = 30 K = 4
10/89 06/90 12/90 03/91 06/91 ( iJ Upgredient Yells 1Gr"'41 # I ni I Ri I
lconc. Rank lconc. Rank lconc. Rank lconc. Rank leonc. Rank
------·------+---··---··--+··----··----+----------··+---··------·+----·-----··~-----··-+···----·+·----·--+
MW·6
MW·9 Hll-10
2.09 (1:9)
0.28 (20) 0.48 (23)
0.4 (22) j<0.1 0.1 C13.Sl <0.1
0.16 C17J <0.1
(6.5) j<0.1 (6.5) <0.1 (6.SJ <0.1
(6.5) j<0.1 (6.Sl <0.1 (6.5) <0.1
(6.S)
(6.S) (6.5)
1S 183 l
Downgradient Wells
1
Gr"'41 # I ni I Ri I
10/ 89 06190 12/90 03/91 06/91 ( i)
lconc. Rank lconc. Rank lconc. Rank lconc. Rank lcorc. Rank ·····---··---+··---·----·-+--··----·---+··---··-----+·---··------+··----·----·+·-----·-+--------+··----·-+
..... 7 .,._8 .,._11 1.14 (27)
2.11 (30)
0.19 (18)
0.87 (28) I <0.1 (6.SJ I 0.12 ( 1S .5) I 0.82 (26) 0.1 C13.5J 0.56 (24) 0.12 ( 1S.S) <0.1 (6.5 l
0.37 C21l 0.6S C25J 0.2 {19) <0.1 (6.Sl
2
3
4
s s s
H = {[12/(30 x31ll [((183'2)/15) + ((103'2)/SJ + {(89.5'2)/5) + ((89.5'2J/S)JJ -(3 x 31) = 4.S16
103
89.5
89.5
4.S16 < 9.348, therefore the null hypothesis ( all wells arOUl'ld the lagoon have the same median cor.certration) holds
Page 2 of 2
•
•
CHROl!IUH
Table 3
one Way Non· Parame-t r i c Anal ys j s of Vari a nee
Statistical Analysis of RCRA Metals on Unfilterec Gr<>Ul\d Water s"""les
Central Transport 1 Inc-..
Charlotte, Horth Carolina
10/89 06/90 12/90 03/91 06/91 ( i) Upgradi ent I/ells I Group # I ni I R; I
le-one. .Rank lcOl".c. Rank lconc. Rank lconc. Rank !cone. Rank
·------------+------------+------------+------------+------------+------------+--------+--------+--------+
HW-6
MW·9
HW-10
0.41 (25)
0 .06 (16)
0.17 (22)
0.08 < 18.5, lo .01 t6.5) 10.01 c6.SJ lo .o7 C17l <0.01 (3) 0.02 (9.5) <0.01 (3) 0.02 .(9.5)
0.04 (13) 0.02 (9.5) <0.01 (3) 0.05 (15)
15 1n.5
o owngradi ent Wells I Group # I ni I R; I
10/89 06/90 12/90 03/91 06/91 Ci) lconc. Rank leonc. Rank )cone. Rank lconc. Rank !cone. Rank
-------------+------------+------------+------------+------------+------------+--------+--------+--------+
HW-7 o.58 <26> 0.21 <24J lo.oe c18.5J 10.04 C13l <0.01 <3l 21 51101.5 MW-8 2.65 (30) <0.01 (3) 1.8 (29) 1.28 (28) 0.02 (9,5) . 3 5 99.5
MW-11 <O .01 (3) 0.16 (16) 0.2 (23) 0.04 ( 13) 0. 78 C27J 4 5 87
H = 4.24; 4.24 < 9.348 therefore rMJll hypothesis holds
LEAD
Upgradi ent Welts I Gro..., # I ni I R i I 10/89 06/90 12/90 03/91 06/91 ( j) /Cone. Rank I Cone. Rank I Cone. Rank I Cone. Rank I Cone. Rank
-------------+-------·----+------------+------------+------------+------------+--------+--------+--------+
Mll-6 0.26 (28) ,0.08 (23.5),0.03 (17) <0.02 (7.5)!<0.02 (7.S)I 1 i 15 I 194 Mll-9 <0.02 (7.5) <0.02 (7.5) <0.02 (7.5) <0.02 (7.5) <0.02 (7.5)
HW-10 0.15 (26) 0.02 (15) 0.03 C17l <0.02 (7.5J 0.04 (19.5)
10/89 06/90 12/90 03/91 06/91 ( iJ
Downgradient Well3 IGr<><.p # I nr I Ri
lcone. Rank lconc. Rank )cone. Rank lcone. Rank f conc. Rank I
-------------+------------+------------+------------+------------+------------+--------+--------+--------+
1111-7
Mll-8
Hli-11
1.45 (30) 10.32 (29) 10.17 (27) 10.08 (23.5),0.05 (21) 0.06 (22) <0.02 (7.5) <0.02 (7.5) <0.02 (7.5) <0.02 (7.5)
<0.02 <7.5> o.04 <19.5) 0.1 c25) <0.02 c7.5) 0.03 c111
H ~ 5.11; 5.11 < 9.348 therefore null hypothesis holds
2
3
4
5
5
5
130.5
51
76.5
.'·"1!' -~ c. 0 O </ "' I L/ BS</ CJ tiQ c~~~,;;;~--·,,+ ~..;-:;;: ,,,.Pj) ...... _..... ....
State of North Carolina f(i}/
Department of Environment, Health, and Natural Resources '\!_!_/
Division of Solid Waste Management
•
P.O. Box 27687 ·Raleigh, North Carolina 27611-7687
James G. Martin, Governor
William W. Cobey, Jr., Secretary octaber 25, 1991 William L. Meyer
Director
Mr. Glen silnpson
Central T.r:ansport, Inc.
600 Melyn:la Road
O:Jarlotte, NC 28208
SUbject: one Tima Disposal of Approxilllately 12,000 Tons of lagoon Closure Sludge
and Soil Stabilized with Ibrtland Cement at the Piedrocmt Sanitary
(I<eJ:nersville) Ian:lfill, (Permit #34-06).
Dear Mr. Simpson:
'!he Solid Waste Management Division has receivecl. a request for
characterization of the subject waste. Based upon the submitte:l infcmnation, the
waste appears to be non-hazardoUs. 'Ille Solid Waste Management Division has no
objection to the sanitary landfill disposal of this waste, if in accordance with
the con:litions liste:l below:
1. 'Ihe a.mer/operator of the landfill approves the disposal.
2. 'Ille waste <Xlntains no free liquids and can be <Xlnfined, corrpacted, and
covered in accordance with the Solid Waste Management Rules (15A NCAC
13B).
3. Approval for sanitary landfill disposal is mq:ilicitly limited to a
"one-time" basis. Further approval by this office will require
submittal of a new Waste Oetennination fonn, and (if applicable), new
analytical data.
Failure to ireet these corxlitions may result in revocation of this approval,
and subsequently, an administrative penalty. If you have further questions or
=rmrents concerning this matter, please !Xlntact this office at [phone].
Sincerely,
/J,.tL>--f.' Mm::tr--
williarn R. Hocutt
Waste Oetennination Coordinator
Solid Waste Section
== Jan McHar9ue -Solid Waste Section
Richard IX>by -Solid waste Section
Jinuny carter -Hazaxdous Waste Section
Katherine O'Neal -Hazardous waste Section
Bill Lewis -Ian'.ifill Management
Jack Wintle; Westinghouse HAZTErn, Inc.: 5280 Panola Industrial
Blvd.; Decature, GI\ 30035
An Equal Opponunlly Mlnnadve Acdon £mployer
' .
CENTRAL TRANSPORT INC.
--j
OSI
J>.
PROJECT SCHEDULE <.D ,_.
p
1 0 ,~~ w
J>. (D
ACTIVITY () l'l :z --j ;o • ::T::~:: ~ I D r
---j
' ;o
' D -z (j) 1J
STATE APPROVAL J 0 ;o ; --j l ()
INSTALL H20 TREAT ._ I I D ;o r 0
SET WELL POINTS f-I --j
-l l'l
H
MOBILIZE MFSD I-=> I z --j
OPERATE WELL POINTS L -
STABILIZATION ~ • DISPOSAL
VERIFICATION SAMPLE ~ l -
BACKFILL -
i I i I i
0 10 20 30 40 60 60
DAYS
START DATE OF 10/3/91 1J
N
, . , ,
William F. Hamner, PhD
August 30, 1991
Page 2
• •
the need to request multiple extensions, Central Transport has decided to wait to request
an extension until after the Contractor begins work and the potential constructability issues
are more defined. It is expected that a formal petition for a closure extension will be
submitted at the end of September.
Please do not hesitate to contact the undersigned or Ms. Terry L. Norman of this office if
you require additional information or assistance.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
~S~-~-* Vice President
GBR:TLN:SPS:dmh
cc: G. Simpson
J. Doyle, Esquire
M. Fleischaker, Esquire
K. Nam, Esquire
T. Norman
S. Shach
O'BRIFN & GERE
• •
Jerome H. Rhodes, Chief
August 16, 1991
Page 2
"Once the sludge has been stabilized, cured, and all testing has been
completed the stabilized sludge will be disposed of as non-hazardous waste in
an appropriate landfill. ... The recommended disposal cell will meet the
double-liner and leachate collection requirements of a RCRA Subtitle C
hazardous waste landfill such as the GSX landfill in Pinewood, South
Carolina."
It is proposed that this paragraph be modified to read as follows:
"Once the sludge has been stabilized, cured, and all testing has been
completed the stabilized sludge will be disposed of as non-hazardous waste in
an appropriate landfill. ... The recommended disposal cell will be the
Piedmont Landfill and Recycling Center in Kernersville, North Carolina."
The Piedmont Landfill & Recycling Center cell construction includes the use of two 60-mil
High Density Polyethylene (HOPE) liners with a bentonite clay mat liner. The leachate
collection system consists of a two-foot sand drainage blanket and HDPE geonet which
transmits leachate into a centrally located sump at the lower end of the cell. The cell is
equipped with an automatic leachate detection and pumping system which conveys leachate
out of the cell for treatment.
Attached please find revised pages F-9 and F-10 of the Closure Plan which have been
modified as described above.
It is OBG's understanding that CTI must submit a waste characterization to Mr. Bill Hocutt
of the Solid Waste Branch to dispose of the stabilized sludge at the Piedmont Landfill &
Recycling Center. As discussed with Mr. Carter on August 6, 1991, Mr. Hocutt has
informed OBG that his office presently has a three month backlog on processing requests.
However, Mr. Carter indicated that he would try to expedite the processing by making Mr.
Hocutt aware of the schedule requirements that CTI must meet.
I J'llRllcN & 13ERc
•
Jerome H. Rhodes, Chief
August 16, 1991
Page 3
•
We appreciate your consideration of this matter and await your response to this letter.
Please do not hesitate to contact the undersigned or Ms. Terry L. Norman of this office if
you require additional information or assistance.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
~ 73.--;;~ ~est,P.E.
Vice President
GBR:TLN:
Attachments
cc: G. Simpson
J. Doyle, Esquire
M. Fleischaker, Esquire
K. Nam, Esquire
T. Norman
S. Shach
CJBRIEI~ & GEllE
• •
August 16, 1991
of service; therefore, the measured volume in April
1988 of approximately 5, 200 cubic yards is not
expected to change.
F-lb(2)bCivl sampling and Testing Program
The frequency of sampling shall be one discrete
sample per 1,000 cubic yards of sludge as
determined using the methods described in USEPA SW-
846 "Test Methods for Evaluating Solid Waste." The
sample will be tested for leachability (TCLP) and
free liquids (Paint Filter Test), and unconfined
compressive strength (ASTM D 2166).
F-lbC2lc Removal of structures
The concrete walls and sluiceways of lagoon 1 will be
excavated and disposed of properly. Contaminated
structures will be stockpiled in a manner that will
prevent a release into the environment using roll-off
boxes or other suitable means. Prior to disposal the
concrete will be decontaminated using similar procedures
as outlined in Section F-lb(2)f(iii) (page 44).
F-lb(2)d Off-Site Disposal
Once the sludge has been stabilized, cured, and all
testing has been completed, the stabilized sludge will be
F-9
Cl'HHIEN 1' r;rnc
• •
August 16, 1991
disposed of as non-hazardous waste in an appropriate
landfill. If for any reason contaminated sludge or soil
is stockpiled prior to treatment, it will be done in a
manner that will prevent a release to the environemt.
Roll-off boxes or any other suitable means may be used to
prevent a release. The recommended disposal cell will
be the Piedmont Landfill and Recycling Center in
Kernersville, North Carolina.
F-1b(2le Backfilling Lagoon Areas
The contaminated sludge and soils will be removed and
disposed of off-site. Soil will be removed to
concentrations which meet acceptable soil clean-up
criteria. The areas formerly occupied by the lagoons
will be backfilled using suitable soil. No asphalt or
materials larger than two inches in diameter will be used
as backfill.
In order to demonstrate that no contaminated materials
will be used as backfill, the contractor will be required
to submit his source for fill for approval by the
engineer prior to beginning to backfill. If
documentation confirming that clean fill is being used is
F-10
fYBRIE~I & GERE
James A. Carter
August 9, 1991
Page 2
• •
Please advise if this letter requires additional information or clarification.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
G~1:>.~t .
George B. Rest P.E. (bJ -t \II)
Vice President
cc: G. Simpson
L. Wellington
M. Fleischaker
K.Nam
J. Doyle
T. Norman
•
Jerome H. Rhodes, Chief
May 22, 1991
Page 2
•
disposal of the stabilized sludges and confirmatory clean sampling.
The sampling results will be submitted to your office prior to
backfilling.
Depending upon the results of the analyses CTI will either:
1). Following your approval of the results, backfill and
regrade the site as specified in Section 02200 1 Appendix
F (including comment #4 in your April 19, 1991 letter),
or:
2). Develop alternative target clean up criteria in a risk
assessment to be submitted for review by the state's and
EPA's toxicologists. The risk assessment will address
the hazardous constituents present and the discussion
will correlate with the waste characteristics discussion
and tables in the closure plan.
The response to specific items in your letter are provided in the
following section.
1) O'Brien & Gere has reviewed the practical quantitation limits
found in SW-846 1 now referred to Estimated Quantitation Limits
(EQL's) in the November 1990 revision to SW-846. The tables
included with each applicable method include the note that
these limits are provided for guidance only and may not be
achievable given the variety of matrices that may be analyzed
using these methods. These EQL's were developed to provide a
basis for evaluating the QA/QC procedures of a laboratory as
well as the quality of the analytical results and were not
developed to form the basis of clean up criteria. However,
given the low permeability (1 x 10 (-7) cm/sec) of the soils
underlying the lagoons and the low migration potential of the
primary contaminant found in the lagoons (phthalates) it is
likely that removal of the sludges and approximately one foot
of underlying soil will yield analytical results which are
below the EQL's. In the event that confirmatory clean
sampling yields concentrations higher than EQL' s, CTI may
submit a risk assessment to the State and EPA for review prior
to regrading the area occupied by the lagoons.
The Closure Plan suggests that the source of volatiles and
semi-volatiles which have been detected in MW-7 is not the
lagoons but some other undetermined source. Ground water
quality data suggests that the concentrations of contaminants
detected in MW-7 are decreasing.
As requested in your April 19, 1991 1 and as further clarified
in a telephone conversation between Steve Shach of OBG and
OBRIEN & Grnc
•
Jerome H. Rhodes, Chief
May 22 1 1991
Page 3
•
Katherine O'Neil on May 8, 1991, OBG has undertaken a
statistical analysis of the RCRA metals detected in the wells
including a comparison of the concentrations in upgradient
wells to the concentrations in downgradient wells.
In order to compare the levels of RCRA-regulated metals (As,
Ba, Cd, Cr, Pb, Hg, Se, Ag) in samples collected from the
upgradient and downgradient bedrock wells on the site, the
Test of Proportions statistical method was used as described
in "Statistical Analysis of Ground-Water Monitoring Data at
RCRA Facilities -Interim Final Guidance" (USEPA, February
1989) .
The upgradient bedrock wells were considered to be MW 6, MW 9,
and MW 10. The downgradient bedrock wells were considered to
be MW 7, MW 8 1 and MW 11. Ground water quality data from MW
14 was not used because the well appears to be located at a
flow divide, and is not considered to be either upgradient or
downgradient; in addition, only two sets of samples have been
collected from this well. An equal number of rounds of data
from all included wells is desired, in order not to weigh one
well any more or less than the others. Ground water quality
data from MW 13 and 16 which were installed in April of 1991,
were not used because only one set of samples has been
collected from these wells. Ground water quality data from MW
1 and MW 2 were not used because these wells are overburden
wells, not bedrock wells.
Ground water quality data from the following sampling rounds
were used: 11/89 1 6/90, 12/90, and 3/91. During each of
these sampling rounds, samples were collected from all six of
the wells and, therefore have been included in the statistical
analysis. A "partial" round of samples was collected from
wells MW 6, MW 7 1 MW 8, and MW 14 in 3/91, in addition to the
"full" round of samples collected during the same month. Data
from the partial round were not used because upgradient wells
were not sampled; an equal number of rounds of data from the
upgradient and background wells is desired, in order not to
skew the data set. Only filtered sample data were used. Data
from the 10/89 sampling round were not used because the
samples were not filtered.
Based upon the formulae included in Section 8.1.2 of the above
referenced document, none of the RCRA-regulated metals show
statistically significant evidence of contamination, when
comparing upgradient and downgradient monitoring wells.
2) During removal of the sludges, decontamination rinsewater will
be managed in accordance with the CMUD Discharge Permit.
O'BRIEN & GERE
•
Jerome H. Rhodes, Chief
May 22, 1991
Page 5
•
sources as pond 3 is the outlet for a larger drainage area that
includes property not owned by Central Transport, Inc.
The professional engineer certification of closure will acknowledge
your April 19, 1991 letter as part of the closure plan and will
state that the above provisions were included in the review of the
closure.
CTI acknowledges that an approval decision on the post-closure plan
will be deferred pending the results of the clean close
determination and the results of the ongoing hydrogeologic
investigation.
Please do not hesitate to contact the undersigned or Ms. Terry L.
Norman of this office if you require additional information or
clarification. Please acknowledge your agreement to the phased
approach to closure at your earliest convenience.
Very truly yours,
O'BRIEN & GERE ENGINEERS, INC.
Corv1 n P 1) 12zst-G~ B':"~~t, P.E. (6, t~ Vice President ... \J LJ
TLN:mjh
cc: J. Doyle, Esquire
M. Fleischaker, Esquire
K. Nam, Esquire
G. Honbarrier
L. Wellington
G. Simpson
T. Norman
M. Wittner
[)'[JRILN & Gelle
• •
SOIL TESTING PROTOCOL -SECTION 02001
02001-1
3883.001
PART 1 -GENERAL
1.01 DESCRIPTION
A. Work Specified
1. Testing of remaining soils for contamination from Lagoon 1
and Lagoon 2.
B. Related Work Specified Elsewhere
1. Earthwork: Section 02200
2. Soil/Sludge Stabilization, Removal and Disposal: Section
02240
1.02 REFERENCES
A. Test Methods for Evaluating Solid Waste, USEPA SW-846.
1.03 SUBMITTALS
A. The Contractor shall submit for approval by the Owner the results of
all analytical testing of soils.
PART 2 -EXECUTION
2.01 SAMPLING
5/91
A. Sample Collection
1. Lagoon 1 and Lagoon 2 will each be divided into four
quadrants subsequent to excavation to construction required
elevations.
2. Two (2) discrete samples shall be collected by the Engineer
from each quadrant: one from the floor of each quadrant,
and one from the side walls, using 3/4 inch diameter Lexan
02001-2
3883.001
• •
SOIL TESTING PROTOCOL -SECTION 02001
tubing.
3. The samples shall be collected by driving the Lexan tube to
a depth of 3 inches _±.0.5 inches and withdrawing the tubing.
4. One (1) sample will be prepared for each quadrant from the
bottom of the excavation, and one (1) sample will be prepared
from the side wall sample. The samples will be stored in a
glass container which will be labeled as to sample location,
date and sampler.
B. Sample Testing
5/91
1. The sixteen samples will be submitted to a laboratory by the
Engineer for analyses. The analytical program will include the
following indicator parameters:
EPA Method No.
Benzene 8240, 624
Bis (2-ethyl hexyl) phthalate 8270
Chloroform 8240, 624
Cresols 8270
1, 1 Dichloroethene 8240, 624
Dichloromethane 8240, 6240
Di-n-butyl phthalate 8270
Methyl Ethyl Ketone 8240, 624
Perchlorethylene 8240, 624
Phenol 8270
5/91
• •
02001-3
3883.001
SOIL TESTING PROTOCOL -SECTION 02001
Pentachlorophenol
Toluene
Trichloroethane
Trichloroethylene
1,2,4-Trichlorobenzene
EPA Method No.
8270
8240, 624
8240, 624
8240, 624
8270
2. When analytical results from item 1 above indicate that the
concentration of indicator parameters are less than or equal
to acceptable soil clean-up criteria then 16 discrete samples
(total) shall be obtained from Lagoon 1 and Lagoon 2.
Samples will be analyzed using the methodologies and
paramters specified in EPA method 8240, EPA method 8270,
and TCLP constituents.
END OF SECTION
5/91
•
EARTHWORK -SECTION 02200
PART 1 -GENERAL
1.01 DESCRIPTION
A. Work Specified
•
02200-1
3883.001
1. Excavation and backfilling including the loosening, removing,
refilling, transporting, storage, and disposal of all materials
classified as "earth" necessary to be removed for the
construction and completion of all work under the Contract.
2. Excavation to the widths and depths shown on the Contract
Drawings, specified or directed.
3. Excavations are to be scheduled and performed in order that
the accumulation of surface and subsurface water is
minimized.
B. Related Work Specified Elsewhere
1. Landscaping: Section 02221
2. Select Fill
3. Structural Excavation, Backfill and Compaction.
4. Soil/Sludge Stabilization, Removal, and Disposal: Section
022240
c. Definitions
1. Excavation (or Trenching)
Grubbing, stripping, removing, storing and rehandling
of all materials of every name and nature necessary to
be removed for all purposes incidental to the
construction and completion of all the work under
Construction;
All sheeting, sheetpiling, bracing and shoring, and the
02200-2
3883.001
5/91
• •
EARTHWORK -SECTION 02200
2. Earth
placing, driving, cutting off and removal of the same;
The maintenance, accommodation and protection of
travel:
The supporting and protection of all tracks, rails,
buildings, curbs, sidewalks, pavements, overhead
wires, poles, trees, vines, shrubbery, pipes, sewers,
conduits or other structures or property in the vicinity
of the work, whether over or underground or which
appear within or adjacent to the excavations, and the
restoration of the same in case of settlement or other
injury;
All temporary bridging and fencing and the removing of
the same.
All materials such as sand, gravel, clay, loam, ashes,
cinders, pavements, muck, and roots or pieces of
timber, soft or disintegrated rock, not requiring
blasting, barring, or wedging from their original beds,
and specifically excluding all ledge or bedrock and
individual boulders or masonry larger than one-half
cubic yard in volume.
3. Backfill
4. Spoil
The refilling of excavation and trenches to the line of
filling indicated on the Contract Drawings or as directed
using materials suitable for refilling of excavations and
trenches; and the compacting of all materials used in
filling or refilling by rolling, ramming, watering, puddling,
etc., as may be required.
Surplus excavated materials not required or suitable for
backfills or embankments.
5/91
• •
02200-3
3883.001
EARTHWORK -SECTION 02200
5. General Fill
General fill shall be approved excavated earth, free
from frost, boulders, rubbish, stumps, trees, roots,
wood, sod or other undesirable materials. Fill will be
furnished from off-site sources. General fill shall be
classified as GW, GP, GM. GC, SW, SP, SM, SC, ML,
or CL in accordance with ASTM D 2487. Also liquid
limit and plasticity index of the soil shall not exceed 40
and 15 respectively. The maximum dry density
determined per ASTM D 1557 shall be no less than 105
psi.
1.02 QUALITY ASSURANCE
A. The owner will engage a soil testing and inspection service for quality
control testing during earthwork operations.
1.03 SUBMITTALS
A. Reports of all field and laboratory tests.
B. Copies of all necessary permits and certifications of waste haulers
and disposal facilities.
C. Properly executed manifests (as required) and written certification of
proper transport and final disposal.
D. Documentation of clean fill.
1.04 REFERENCES
A. American Society for Testing and Materials (ASTM)
1.05 JOB CONDITIONS
A. Existing Utilities: Location of existing underground and overhead
utilities in areas of work shall be the responsibility of the Contractor.
If utilities are to remain in place, Contractor shall provide adequate
means of support and protection during earthwork operations.
02200-4
3883.001
• •
EARTHWORK -SECTION 02200
B. Protection of Persons and Property: Contractor shall barricade open
excavations occurring as part of this work.
C. Contractor shall protect structures, rail lines, utilities, sidewalks,
pavements, and other facilities from damage caused by settlement,
lateral movement, undermining, washout and other hazards caused
by earthwork operations.
O. Work shall be organized so as to minimize disruption to ongoing
activities at the facility, i.e. truck washing operations, etc ..
PART 2 -PRODUCTS
5/91
2.01 DESCRIPTION
A. Wood Sheeting and Bracing
1. Shall be sound and straight; free from cracks, shakes and
large or loose knots, and shall have dressed edges where
directed.
2. Shall conform to National Design Specifications for Stress
Grade Lumber having a minimum fiber stress of 1200 pounds
per square inch.
B. Steel Sheeting and Bracing
1. Shall be sound
2. Shall conform to ASTM A328 with a minimum thickness of 3/8
inch.
5/91
•
EARTHWORK -SECTION 02200
PART 3 -EXECUTION
3.01 UNAUTHORIZED EXCAVATION
A. Limits of Excavation
•
02200-5
3883.001
1. Excavations shall be made to the elevations of subgrade
specified.
2. Whenever excavations are carried beyond or below the lines
and grades shown on the Contract Drawings, or as given or
directed by the Engineer, all such excavated space shall be
refilled with select fill material as directed by the Engineer. All
refilling of unauthorized excavations shall be at the
Contractor's expense.
3 All material which slides, falls or caves into the established
limits of excavations due to any cause whatsoever, shall be
removed and disposed of at the Contractor's expense and no
extra compensation will be paid the Contractor for any
materials ordered for refilling the void areas left by the slide,
fall or cave-in.
4. In no case will undercutting excavation faces be permitted.
B. Dust Control
1. The contractor shall provide control of dust and m1rnm1ze
exposure to airborne dust generated at all times in all areas
being excavated, graded or otherwise disturbed as well as all
access roads traveled by equipment. As necessary or as
directed by the Engineer a water spray will be applied directly
over the area of activity or some equivalent, approved means
shall be used to control dust. The use of calcium chloride or
oils to control dust on surfaces is prohibited.
02200-6
3883.001
• •
EARTHWORK -SECTION 02200
3.02 REMOVAL OF WATER
5/91
A. General
1. The Contractor shall at all times during construction, provide
and maintain proper and satisfactory means and devices for
the removal of all water entering the excavations, and shall
remove all such water as fast as it may collect, in such
manner as shall not interfere with the execution of the work.
2. Unless otherwise specified, all excavations which extend down
to or below the static ground water elevations shall be
dewatered by lowering and maintaining the ground water
beneath such excavations at all times when work thereon is
in progress during subgrade preparation and the placing of
the structure or pipe thereon.
3. Where the presence of fine grained subsurface materials and
a high ground water table may cause the upward flow of
water into the excavation with a resulting quick or unstable
condition, the Contractor shall install and operate a wellpoint
system to prevent the upward flow of water during
construction.
4. Water pumped or drained from excavations, or any sewers,
drains or water courses encountered in the work, shall be
disposed of in an appropriate manner without injury to
adjacent property, the work under construction, or to
pavements, roads, drives, and water courses.
5. Any damage caused by or resulting from dewatering
operations shall be the sole responsibility of the Contractor.
6. If dewatering is required, the North Carolina Department of
Environment, Health, and Natural Resources, Office of Solid
Waste Management shall be notified.
5/91
•
EARTHWORK -SECTION 02200
B. Work Included
1. Excavation of lagoon sludges.
•
02200-7
3883.001
2. Furnishing and operation of pumps, wellpoints, and
appurtenances needed to maintain thorough drainage of the
work in a satisfactory manner.
C. Wellpoint Systems
1. Installation
a. The wellpoint system shall be designed and installed
by or under the supervision of an organization whose
principal business is wellpointing and which has at
least five consecutive years of similar experience and
can furnish a representative list of satisfactory similar
operations.
b. Wellpoint headers, points and other pertinent
equipment shall not be placed within the limits of the
excavation in such a manner or location as to interfere
with the laying of pipe or trenching operations or with
the excavation and construction of other structures.
c. Detached observation wells of similar construction the
wellpoints shall be installed at intervals of not less than
50 feet along the opposite side of the excavation from
the header pipe and line of wellpoints, to a depth of at
least five feet below the proposed excavation. In
addition, one wellpoint in every 50 feet shall be fitted
with a tee, plug and valve so that the wellpoint can be
converted for use as an observation well. Observation
wells shall be not less than 1-1/2" in diameter.
d. Standby gasoline or diesel powered equipment shall be
provided so that in the event of failure of the operating
equipment, the standby equipment can be readily
02200-8
3883.001
• •
EARTHWORK -SECTION 02200
connected to the system. The standby equipment
shall be maintained in good order and actuated
regularly not less than twice a week.
2. Operation
a. Where wellpoints are used, the ground water shall be
lowered and maintained continuously (day and night)
at a level not less than two feet below the bottom of
the excavation. Excavation will not be permitted at a
level lower than two feet above the water level as
indicated by the observation wells.
b. The effluent pumped from the wellpoints shall be
examined periodically by qualified personnel to
determine if the system is operating satisfactorily
without the removal of fines.
c. The water level shall not be permitted to rise until
construction in the immediate area is completed and
the excavation backfilled.
3.03 SHEETING AND BRACING
5/91
A. Installation
1. The contractor shall furnish, place and maintain such sheeting
bracing, and shoring as may be required to support the sides
and ends of excavations in such manner as to prevent any
movement which could, in any way, injure the pipe, effect the
limits of the site, or other work, diminish the width necessary
for construction, or otherwise damage or delay the work of
the Contract.
2. In no case will bracing be permitted against pipes or other
structures in trenches or other excavations.
3. Sheeting shall be driven as the excavation progresses, and in
such a manner as to maintain pressure against the original
ground at all times. The sheeting shall be driven vertically
5/91
•
EARTHWORK -SECTION 02200
•
02200-9
3883.001
with the edges tight together, and all bracing shall be of such
design and strength as to maintain the sheeting in its proper
position
4. The contractor shall be solely responsible for the adequacy of
all sheeting and bracing.
B. Removal
1. In general all sheeting, bracing, whether of steel, wood or
other material, used to support, the sides of trenches or other
open excavations, shall be withdrawn s the trenches or other
open excavations are being refilled.
2. After final use, all sheeting shall be cleaned and
decontaminated and removed from the site.
3. If sheeting is ordered to be left in place, it shall be cut off or
driven down as directed so that no portion shall remain within
1 inches of the finished ground surface.
3.04 BACKFILLING
A. General
1. The contractor will be required to submit his source for fill for
approval to the Engineer prior to beginning to backfill. If
documentation confirming that clean fill is being used is not
provided, the Contractor will be required to take one sample
of fill per 50 cubic yards and analyze for volatiles,
acid/base/neutral extractables, and TCLP constituents and
submit the results to the Engineer prior to the placement of
the fill.
2. All excavations shall be backfilled to the original surface of the
ground or to such other grades as may be shown, specified
or directed.
02200-10
3883.001
5/91
• •
EARTHWORK -SECTION 02200
3. Backfilling shall be done with general fill which can be
satisfactorily compacted during refilling of the excavation. In
the event the excavated materials are not suitable, Special
Backfill as specified or ordered by the Engineer shall be used
for backfilling. Unsuitable, uncontaminated excavated
materials are to be removed from the job site by the
contractor at his expense. Suitable, uncontaminated materials
shall be stockpiled separately from contaminated materials
and used for general backfilling.
4. Any settlement occurring in the backfilled excavations shall be
refilled and compacted.
B. Unsuitable Materials
1. Stones, pieces of rock or pieces of pavement greater than 2
inches in any single dimension shall not be used in any
portion of the backfill.
2. All stones, pieces of rock or pavement shall be distributed
through the backfill and alternated with earth backfill in such
a manner that all interstices between them shall be filled with
earth.
3. Frozen earth shall not be used for backfilling.
C. Compaction
1. The compaction shall be as specified for the type of
earthwork, i.e., structural, trenching or embankment.
a. Compaction specified shall be 90 percent of maximum
dry density.
b. The compaction equipment shall be suitable for the
material encountered.
5/91
. " " '''~"""'
• •
02200-11
3883.001
EARTHWORK -SECTION 02200
2. Where required, to assure adequate compaction, in-place
density testing shall be made by an approved testing
laboratory.
a. The moisture-density relationship of the backfill material
shall be determined by ASTM 0698, Method 0.
1. Compaction curves for the full range of
materials used shall be developed.
b. In-place density shall be determined by the methods of
ASTM 1556 or ASTM 02922 and shall be expressed as
a percentage of maximum dry density.
3. Where required, to obtain the optimum moisture content, the
Contractor shall add, at his own expense, sufficient water
during compaction to assure the specified maximum density
of the backfill. If, due to rain or other causes, the material
exceeds the optimum moisture content, it shall be allowed to
dry before resuming compaction or filling efforts.
4. The Contractor shall be responsible for all damage or injury
done to pipes, structures, property or persons due to
improper placing or compacting of backfill .
3.05 STORAGE OF MATERIALS
A. Excavated Materials
1. All on-site excavated materials shall be stored at on-site
locations so as not to endanger the work, and so that easy
access may be had at all times to all parts of the excavation
and so as not to interfere with the owner's operation. All
suitable noncontaminated material shall be stored on-site and
used for general backfill.
2. Any soils located within one foot of the bottom or sides of
Lagoon 1 and 2 will be considered contaminated soil. Other
02200-12
3883.001
• •
EARTHWORK -SECTION 02200
soil that is excavated during remediation will be classified as
contaminated or uncontaminated depending on results of
chemical analyses. The Contractor shall be required to take
one sample of fill per so cubic yards and analyze for volatiles,
acid/base/nuetral extractables, and TCLP constituents, and
submit the results to the Engineer prior to the placement of
the fill. Soils in which constituents are detected above PQLs
will be considered contaminated.
3. Temporary Staging in the form of placing material on
visqueen, covering with visqueen, and providing sufficient
ballast to maintain the cover (i.e. placing of planks or rubber
tires on top of the cover) and prohibit migration of dust and
materials from the containment area will be allowed for both
contaminated and non-contaminated materials.
4. All potentially contaminated soil shall be stored separately
from non-contaminated soil. For this contract contaminated
soil is defined as soil that does not meet the criteria listed in
Table 10 of the document entitled "Closure /Post Closure Plan
for Central Transport, Inc., Charlotte, North Carolina".
3.06 DISPOSAL OF MATERIALS
5/91
A. Disposal
1. All suitable non-contaminated material shall be used for on-
site backfilling.
2. All other material will be disposed of as specified in Section
02240.
3.07 OTHER REQUIREMENTS
A. Drainage
1. All material deposited in roadway ditches or other water
courses shall be removed immediately after backfilling is
completed and the section grades and contours of such
ditches or water courses restored to their original condition,
5/91
•
EARTHWORK · SECTION 02200
•
02200-13
3883.001
in order that surtace drainage will be obstructed no longer
than necessary.
B. Unfinished Work
1. When, for any reason, the work is left unfinished, all trenches
and excavations shall be filled and all roadways, sidewalks
and watercourses left unobstructed with their surfaces in a
safe and satisfactory condition. The surface of all roadways
and sidewalks shall have a temporary pavement.
C. Hauling Material on Streets
1. When it is necessary to haul material over the streets or
pavements, the Contractor shall provide suitable tight vehicles
so as to prevent deposits on the streets or pavements. In all
cases where any materials are dropped from the vehicles, the
Contractor shall clean up the same as often as required to
keep the crosswalks, streets and pavements clean and free
from dirt, mud, stone and other hauled material.
D. Hauling Material Offsite
1. Prior to leaving the site, all equipment which has been in
contact with the excavated soils shall be decontaminated to
the satisfaction of the Engineer. Decontamination of
equipment shall be in accordance with Specification Section
Equipment Decontamination Procedures.
Decontamination of equipment shall take place on-site on a
decontamination area constructed, operated, and maintained
by the Contractor. The decontamination area shall consist of
an impermeable are (sloped to a sump area) with appropriate
height curbing and in accordance with the aforementioned
Specified Section . The contractor shall be responsible
for the complete operation of the decontamination area and
shall treat all wash water collected in accordance with all
Federal, State, and Local regulations.
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2. All excavated material destined for offsite disposal at a
chemical waste disposal facility will be transported in suitable
containers in accordance with 40 CFR Part 761. Bulk trailers
shall be watertight.
3. The Contractor is responsible for obtaining all state, county,
and town permits, or variations to allow transport of any and
all materials or equipment on public roadways.
D. Safety Equipment
1. The Contractor shall provide all necessary safety equipment
to his employees, the Engineer and his representatives, and
the Owner's representatives. The following minimum safety
equipment will be used at all times by all personnel located
within the limits of the site where contact with contaminated
material may result.
Hard hats and steel reinforced protection boots.
Safety glasses or goggles complying with OSHA
Standard ANSI 287.1-1968.
Disposal rubber boots or overshoes.
Nonporous disposable coverall.
Full face respirator with high-efficiency dust/mist/
particulate organic vapor combination cartridges.
All disposal safety equipment shall be stored at and disposed
of at locations approved by the Engineer. The use and care
of Safety Equipment shall be in accordance with the approved
Health and Safety Plan.
2. The Contractor shall comply with all of the provisions covering
workers involved in hazardous waste operations as set forth
in 29 CFR 1910.120.
3. The Contractor shall comply with all safety standards required
by the Owner.
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E. Dust Control
•
02200-15
3883.001
1. It shall be the sole respons.ibility of the Contractor to control
the dust created by any and all of his operations to such a
degree that it will not endanger the safety and welfare of the
general public.
F. Test Pits
1. For the purpose of obtaining detail locations of underground
obstructions, the Contractor shall make excavations in
advance of the work. Payment for the excavations ordered by
the Engineer will be made under an appropriate item of the
Contract.
G. Stability of Excavations
1 . The Contractor shall shore and brace excavations as required
to prevent cave-ins, and to protect adjacent structures,
facilities and utilities.
2. The Contractor shall remove shoring when no longer required,
unless otherwise directed or approved by the Engineer.
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