NCD981023260_19920926_Potters Septic Tank Service Pits_FRBCERCLA ROD_Record of Decision 1992 - 2000-OCR

•
JAMES 8. HUNT JR.
GOVERNOR
BILL HOLMAN
SECRCTA.RY
. '
~•I WILLIAM L. MEYER•~.(
t: DIRECTO_Ri•.· '. I -';\,
Ms. Beverly Hudson
• -~~---~ .: N6~s,2AROLINA DEPARTMENT OF
ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WASTE MANAGEMENT
26 September 2000
Superfund Branch, Waste Management Division
US EPA Region IV
61 Forsyth Street. SW
Atlanta, Georgia 30303
SUBJECT: Concurrence with Record Of Decision Amendment to Ground Water
Remedial Action
Potter's Septic Tank Service Pits
Sandy Creek, Brunswick County
Dear Ms. Hudson:
The State of North Carolina has reviewed the Record of Decision (ROD)
amendment received by email on 26 September 2000 for the Potter's Septic Tank
Service Pits Superfund site and concurs with the selected remedy, subject to the
following conditions:
! . State concurrence on the ROD amendment for this site is based solely
on the information contained in the amendment received by the State
on 26 September 2000. Should the State receive new or additional
information which significantly affects the conclusions or amended
remedy contained in the ROD amendment, it may modify or
withdraw this concurrence with written notice to EPA Region IV.
2. State concurrence on this ROD amendment in no way binds the State
to concur in future decisions or commits the State to participate,
financially or otherwise, in the clean up of the site. The State
reserves the right to review, overview comment, and make
independent assessment of all future work relating to this site.
wm CifN·liiHN·N
\ 646 MAIL SERVICE CENTER, RALEIGH, NORTH CAROLINA 27699-1646
401 OBERLIN ROAD, SUITE 1 50, RALEIGH, NC 27605
f>HONE 91 9-733-4996 FAX 91 9-7 l 5-3605
AN EQUAL OPPORTUNITY I AFFIR"'IATJVE ACTION EMPLOYER • 50% RECYCLED/I 0% POST-CONSUMER PAPER
3 .• If, after remediation is complete, the. residual risk level exceeds
1 o·6, the State may require deed recordation/restriction to document
the presence of residual contamination and possibly limit future use
of the property as specified in NCGS 130A-3 l 0.8
4. State concurrence on the ROD amendment is conditional with a work
plan being submitted within 60 days of receipt of this letter. The
work plan shall consist of a ground water monitoring plan as
discussed in section 3.0 of the ROD amendment. In addition, the
Groundwater Section requires that any person who submits a request
for monitored natural attenuation shall notify all property owners and
occupants underlain by the contaminant plume of the nature and of
the request for MNA. Notification shall be made by certified mail
(please see Title 15A NCAC 21.0114.) A list of property owners
and occupants who need to be notified should be included in the work
plan as well as a copy of the notification letter that will be sent to the
property owners and occupants.
The State of North Carolina appreciates the opportunity to comment on the
ROD amendment and looks forward to working with EPA on the final remedy for
the subject site. If you have any questions or comments, please call me at 919 733-
2801, extension 291.
cc: Phil Vorsatz, NC Remedial Section Chief
Jack Butler, Chief NC Superfund Section
Nile Testerman, NC Superfund
Sincerely,
Grover Nicholson, Head
Remediation Branch
Superfund Section
03/11/96 09:41 EPA REGION JU t..ASTE MGT PROGRel1S 002 • • ,fU: O fi · 1996
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
R!:GION 4
346 CpUR'fLAND STREET, N.E.
A'll.ANTA; GEORGIA 303M
U.S. ENVTRONMRNTAL PROTECTION AGdNCY REGION IV .
SUPERFUND PROGRAM EXPLANATION OF SIGNIFICANT, DIFFERENCE
POT~R'S SBPTIC TANK SERVICl\fil;TS ;~
SANPX c EEK « BRUNSWICK COUNTY • N ({TH C ~LINA
Introduction
The purpose of this Explanation of Signifibant Differences
(ESD) is to provide information to the public on the changea to
the remedial activities t:or the .eotter·s septicl.Timk service Pit"
Site in Sandy Creek, Brunswick County, North,Ca~olina [the Site),
The remedial action selected by the U.S. Environmental Protection
Agency, Region IV (EPA), the lead agency for re~edial activities
at the Site, is described in detail in the RecoFd of.Decision
(ROD) signed on August 5 1 1992. The ROD provid~" for the
remediation of soil and groundwater at the Site,
EPA ha~ made one chan9c to the implcmcnta.tion of the
recommended soil remediation tor the Site, EPA has determined
that the remediation goal for lead should be 40P ppm rather than
25 ppm as noted in the ROD. This change represents a significant
difference from the ori9inal remediation 9oal fpr lead set out in
the ROD. The public will be notified of the change in the ROD
through the publication of the ESD, The ESP isl being issued by
EPA with the concurrence of the North Carolina Department of
Environment, Health and Natural Resources (NCDE~)•
This ESD is issued as part ot EPA's public: participation
responsibilities under Section 117(c) of the Comprehensive
Environmental Response, Compensation and Liability Aot (CERCLA),
42 U,5,C, S 9617(c)1 as amended by the 5uperfund Amendments a.nd
Reauthorization Act of 1986, and Section 300.43'5(c) (2) (i) of the
National Oil and Hazardous Substances Pollution Contingency Plan
(NCI') 1 40 C,F,R, Part 300, This notice inolude'e the info;z;mation
which provide the basie for the change 1 the rea'8oll8 why the
change is appropriate, and a discussion of the e~ent of the
change, The administrative record file for thi's Site contains
the information upon which the r~medy selection was baaed.
including the ROD and Ree!?onelveqeea Summary, ~his EBD will
become part or that record which is located at the following
locations:
03/11/96 09:42 EPA REGION IV WASTE MGT PROGRR'1S 003 •
Information Repository
Columbus County Library
East Columbus Branch
P.O. Box 27, Highway 87
Reigelwood, North Carolina 28456
[phone]
Site History
•
EPA Region rv Offic(;!
u,s. EPA.Records Center
Ground Floor
345 Co~rtland St. NE
Atlanta, Georgia 30365
(404)3~7,0506
The Potter's Pits Site is located in a rural section of
Brunswick County, North Carolina, in a residential community
known as the Town of sandy creek. Sandy Creek:is subdivided into
one to two acre lots, each with a private domestic water well,
There are approximately 150 residential lots of which 70 are
currently occupied.
Between 1969 and 1976, before the land was developed for
re~idential use, the skipper family operated siudge hauling and
oil spill cleanup oompanieEI in thi;:i area. Waste disposCtl pits
were operated in and around the ·sandy Creek ar<il.a. Disposal
practices consisted of placing waste petroleum'products and
septic tank sludge in shallow unlined pits or directly on the
land surface. '
The Potter's Piter Site was divided by EPA!into three study
areas; Areas 1 and 3 are located in residentiai lots within Sandy
Creek, and Area 2 was located approximately 1.$ miles north
across u.s. Highway 74/76. Areal comprises the actual Potter's
Pits Site. Area 3 was included in the investigation because
hiotorical aerial photographs suggested that this area might have
been used as a disposal Site. During the Remedial Investigation
(RI) phase, Area 3 was determined not to be a problem. Area 2
was selected based on preliminary information which indicated
that wastes may have been disposed of in this ~rea. However,
l;lubsequent investigations did not; produce any ~delitional
information or evidence 0£ E!uch di,.posal, emd Area 2 wati removed
from further consideration.
In August 1976, an unlined pit in Areal failed and allowed
approxiillcl.tely 20,000 gallons of oil to escape. 'l'he oil flowed
into two streo.ms: Chinnis Br«nch and then into'Rat:tlesnake
Branch. The United States Coast Guard, acting;purauant to
Section 311 of the Clean Water Act, r:-emoved tl')e spilled oil from
Rattlesnake Branch. Also in August 1976, Mr. Otto Skipper
(brother of Ward Skipper) began pumping out the oil remaining in
the breached disposal pit (Ai'ea 1). Approximately 20,000 gallons
of. oil were 1-emoved from this pile ,u,d transport;ed to l'"ort Bragg
Military Reservation in Fayetteville, North Ca~olina.
-2-
03/11/96 09:43 EPA REGION IIJ i,,RSTE MGT PROGRAMS 004 • •
The oil stored in three other pits at the,Site, as well as
the oil recovered from the receiving stream, w~s also taken to
Fort Bragg, In addition, approKimately 150 dump truck loads of
oil sludge and oil stained dirt were excavated'and hauled to
Brunswick County Landfill in Leland, North Car¢lina, for final
disposal. The thick oil sludge that could not;be pumped was
mixed with sand and buried on site. ·
The Skipper Estate changed ownership in l~B0. Wachovia
State Bank. through foreclosure, took possession of the property
in January 1980. Investment Management Corporation later
purchased the property and subdivided it for residential
development. This development became known as;Sandy creek Acres
and later as the Town of Sandy Creek, In July:l9B3, owners of
the property found waste materials buried in their yard,
(formerly Pit Area 1). The State of North Carolina sampled the
soil and groundwater. Analysis of these sampl!!!S confirmed the
presence cif contamination. The Site owner's water wells were
condemned, and they were connected to a neighbqir's well,
In September 1983, EPA and the Region IV ~ield Investigation
Team (FI'I') performed an electromagnetic survey:of the Site,
monitored the air, collected soil, surface water, and grou11dwater
samples for laboratory analysis. In ~ebruary 1984, EPA-Region IV
u"'ed ground penetrating i;adar (GPR) to fui;ther define the Site
bo\lndaries.
In March 1984, an immediate Removal Action at the Potter's
Pits Site (Area 1) was requested by the EPA Office of Emergency
and Remedial Response. on Maren 21, 1984, a removal was begun
centering around Area 1, A total of l,770 tons of oily slud~e
and contaminated soils were excavated and transported to a
hazardous waste landfill in Pinewood, S.C. Soil removal
activities were completed on April 2 1 1984. ·
In May 1984, EPA-Region IV proposed a grounawater monitoring
plan to determine if the Potter'fll l?itfll Site (Areal) presented a
threat to surrounding groundwater sources. Co*tamination of the
shallow aquifer had been documented at the Sit~ (during the
September 1983 FIT investigation) in groundwater samples taken
from both a residential a11d a monitoring well 9n Site, However,
in order to characteriz;e the n1;1ture llnd extent'of the groundwater
contamination in this area, additional wells were proposed. Nine
monitoring wells were subse~uently installed arid sampled by EPA.
The locations of these wells were based on the assumption that
the groundwater flow was in a northeasterly direction, The
samples were analyzed for volatile org-anic comwounds. Relatively
high concentro.tions of benz.ene, ethylbenzene, toluene, and
xylenes (BETX) were detected ii\ soma of tha grou1\dwatar aamples,
EPA conducted a Preliminary Assessment (PA) of the Site in
September 1987. The PA revealed soil and water contamination at
-3-
03/11/96 09:43 EPA REGION IV t.1'.1STE MGT PROGRAMS 005 • •
the Site. Subsequently, EPA added Potter's septic Tank Service
Pits Site on the National Priorities List and assumed lead
responsibility for the Site.
The wells were re-sampled in 1988 by the State of North
Carolina. The<>e <>ample<> were analyzed f.or volatile organics,
phenols, priority pollutant me\;als, and aeve:r·aiL nutrient<>. BET:X:
and Dhenols were the predominant contaminants detected. In
addition, the 1988 data indicated the possibility of low level
benzene, ethyl.benzene, and xylene:, in a "deep•;well which would
indicate that the "deep" aquit:er had now been affected.
The Remedial Investigation (RI) Report, cpmpleted in
December of 1991, consisted of a two-phase inv~stigation. The
investigation consisted of analysis of the sediments, surface
water, groundwater, surface soil, and subsurfai::e soil at the
site. The RI a.lso included an analysis o! the potential dangers
to human health and the enviromnen\;. Based on the ~-e:,ult" from
the RI, EPA determined that remediation of the soil and
groundwater was necessary to protect human health and the
environment.
A Fea.,ibility Study (FS) was conducted to!<1-nalyze the
remedial alternatives. Each alternative was evaluated using the
following factors: effectiveness of soil and ~toundwater
remediation, cost effectiveness, technical fea~ibility,
institutional requirements, and the degree of protectiveness to
human health and the environment. ·
On May 12, 1992, ~PA held a public meeting at the Hood Creek
Community Center, in Sandy Creek, North Caroliµa. At this
meeting, EPA discussed the remedial alternatives developed in the
FS and reviewed the preferred alternative. Thell.OD was signed
ond issued on Auguet 5, 1992. EPA began the remedi<ltion at the
Site in 1993, using Superfw~d monies. ·
Description of the Remedy
A complete description of the selected re~edy is contained
in the. ROP _which is av1;1.il1;1.ble at the informati,;m repository in
the Columbus County Library and the U.S. EPA Records Center. In
summary, the ?otter's Pits remedy addressed th~ contaminated soil
and groundwater present at the Site. The remedy includes:
• MIGRATION CONTROL (remediation O! contaminated
groundwater). Groundwoter will be eitracted ui:oing
extraction wells located withi11 and near the periphezy
of the plume. Extracted groundwater will be treated
on-site using an above-ground treatment:. process which
will include precipitation, flocculation, and
-4-
03/11/95 09:44 EPA REGION JU LJ'.=lSTE MGT PROGRi'l'IS 005 • •
filtration to remove metals; aud air, stripping to remove volatile organic compound:, (VOCs), Aft:ex-t,:eatmont to meet the NaC.ional Pollu,tanc. Discharge Elimination System (NPDES) permit requirements, the extracted groundwater will be discharged to Chinnis Branch. ·
• 130UKCI!: CONTROL (remediation of contaminated soil). On-site soil wilh coutaminant concen~ration levels above cleanup standards will be excavated and treated, Contaminated :;oil will be treot.ed on~s;lte by a low-tempero.ture tl1ern1al desorption (LTTD) unit. Each batch will be tested to determine whether concentrations of hcaavy metals exceed cleanup stand,1n:d~; if so, the soil will be· ato.bili,:ed uaing ex:-:;itu :soi'1 Lreat1l1<:ut.
Description of Significant Di[fenmce
El?A has made one changsa L.u the implernenca'.ioion of the recommended ~oil remediation fore the 13ite. !!PA has determined tho.t the remediat.ion goal for lead should be 4PO ppm :rather than 25 ppm iis noted in Lhe ROD. This change was made as a result of a review al: data collected duL·ing preliminai-y field work. The revieed cleon-up level would <:1lso mei.ke Ute remedy more cost-ef fect.ive. In addition, Lhis cl1ange is protecl;ive of human health and the environment, and complies with applicable Stat<'! laws es provided under SecLiou:s 121 of CERCLA. As noted above, NCDEHNR concurs with the revised remediation goa.l tor lead.
Change in the Boil Remediation
In the ROD, thca original soil excavation clean-up goal of 25 ppm for leo.d wois bc:ii,ed on a leacl1ate model that was t:oo conservative in its asswnptions. A leachate model determines a soil clean-u:D Qoal that is J.)rotective of groundwater. When this leachato model's calculated value of 25 ppm was compared to a riak-bcwed concentration protective of lrnman health (400 ppm), the lower Vellue was chosen as a soil clean-up goal. However, a new leachate model l·eflectirn;r the principles embodied in a risk-bac;0d analysis was usc,d to cal.cul.ate a soil ol-,an-up goal tl1at, is atill protective of groundwa\:.<01i. Therefore, the model demon:,t.rates the1l it the ri:sK-based goal O[ 400 ppm Of lead in soil is used as a clean-up goal it would be protective of Qroundwe,ter 1md human health.
!!PA is J.n u·,e process of remectiating tne soil in accordance with the change outlined in the ESD.
-5-
03/11/96 09:45 EPA REGION IV WASTE MGT PROGRAMS 007 • •
Conclusion
The above-outlined change in the lead remediation level,
represents a significant difference from the remedy outlined in
the ROD. considering the new information that has been developed
and the change that has been made to the sele¢tell remedy, EPA and
NCDEHNR beii,we that tha remedy remains protec'tive ·of human
health and the environment, complies with Federal and State
reguirements that are applicable or relevant and approDriate to
this remedial action, and is cost effective. In addition, the
revised remedy utilizes permanent solutions and resource recovery
taohnologieei to the mox:i.rnum extent practicable for this Site,
ard , cting Director
W te M~nagement Division
Region IV
U.S. Environmental Protection Agency
-6-
State of North calina
Department of Environment,
Health and Natural Resources
Division of Solid Waste Management
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
William L. Meyer, Director
March 11, 1996
Ms. Beverly Hudson
Superfund Branch, Waste Management Division
US EPA Region IV
345 Courtland Street
Atlanta, Georgia 30365
SUBJECT: Review of Explanation of Significant Difference
Potter's Septic Tank Service Pits
Sandy Cre~k, Brunswick County
Dear Ms. Hudson:
The State of North Carolina has reviewed the Explanation of Significant Difference dated
February 6, 1996 for Potter's Septic Tank Service Pits Superfund site and concurs with the selected
remedy, subject to the following conditions:
I. State concurrence on the Explanation of Significant Differences (ESD) for this site
is based solely on the information contained in the ESD received by the State on 11
March I 996. Should the State receive new or additional information which
significantly affects the conclusions or amended remedy contained in the ESD, it
may modify or withdraw this concurrence with written notice to EPA Region IV.
2. State concurrence on this ESD in no way binds the State to concur in future decisions
or commits the State to participate, financially or otherwise, in the clean up of the
site. The State reserves the right to review, overview comment, and make
independent assessment of all future work relating to this site.
3. If, after re1I1ediation is complete, the total residual risk level exceeds J0·6, the State
may require deed recordation/restriction to document the presence of residual
contamination and possibly limit future use of the property as specified in NCGS
130A-310.8
P.O. Box 27687, Raleigh. North Carolina 27611-7687 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post-consumer paper
• •
The State of North Carolina looks forward to working with EPA on the final remedy for the
subject site.
Sincerely,
U~JJJ_
/ ;rover Nicholson, ead
. __ . ___ .Remediation Branch _ . _ . ______ . _____ _
cc: Curt Fehn, NC Remedial Section Chief
Michael Kelly, Deputy Division Director
Nile Testennan, NC Superfund
Randy McElveen, NC Superfund
S uperfund Section
• •
17 July 1995
MEMORANDUM
TO:
FROM:
Subject:
File
Nile Testerman ~
Environmental Engineer
Superfund Section
Fax of Soil Remediation Levels for Lead Using Summers Model
Potter's Septic Tank Service Pits
Sandy Creek, Brunswick County
On 17 July 1995, a representative of the NC Superfund Section received and reviewed an internal
memo from EPA on the revised soil cleanup goal for lead. Mr. Bernie Hayes using the Summers
Model calculated a new soil cleanup level. The revised soil cleanup level calculated for lead is 415
mg/kg. Mr. Hayes used data from the Remedial Investigation report and recent data collected at the
site. A new Kd or distribution coefficient for lead was calculated from the new data. A total lead
concentration of 43.2 mg/kg and a TCLP concentration of25 mg/L were used to determine a Kd
of 1728 L/kg. The 25 mg/L value is 1/2 the detection level as all TCLP lead concentrations were
nondetect at 50 mg/L. The calculated Kd value of 1728 L/kg is very close to an earlier Kd calculated
by William O'S teen and is in the range of literature values. The most conservative assumptions were
made in the calculations except for the value for hydraulic gradient. The average value of 0.045
rather than the conservative value of0.03 was used. If 0.03 is used the calculated soil cleanup level
is 306 mg/kg. If 0.045 is used, the soil level is 415 mg/kg. EPA seems to want a modeled value
above 400 mg/kg so that the dermal contact value of 400 is used as the cleanup level. Our office
does not have a problem allowing the average hydraulic gradient to be used in the calculation as all
other parameters are the most conservative.
• ABCPCE.XLS •
SUMMERS MODEL OF VADOSE ZONE TRANSPORT
SITE INFORMATION
!Site Name:
City:
County:
Potter's Pit
CHEMICAL-SPECIFIC DATA
Chemical Name:
Sample Number:
Recharge Rate (R), ft/yr=
Hydraulic Conductivity (K), ft/d=
Hydraulic Gradient (I), ft/ft=
Mixing Zone Depth (b), ft=
Fraction of Organic Carbon (foe)=
Area of soil Contamin. (A), ft'2=
Width of Contam. Normal to GW
Flow Direction (W), ft=
Lead
SITE-SPECIFIC DATA
25.7
0.03
5
26,000
200
CALCULATED VARIABLES
Qp=Volumetric Flow Rate of
Infiltration = W N365 =
Qa=Volumetric Flow Rate of
GW=K'l'b'W=
Kd=Soil/Water Partition
Coefficient=foc'Koc=
71.23 ft'3/day
771 ft'3/day
1728 ml/g
SUMMERS MODEL CALCULATIONS
Source:
Source:
Weston FS Report
Weston FS Report
Weston FS Report
Aquifer Thickness
Estimate
Weston FS Report
Weston FS Report
Setting Groundwater Concentration to the Groundwater Standard and Estimating Soil Cleanup
Level
Cgw=Allowable GW Concentration=
Csoil=Soil Cleanup Level =
Kd'Cgw'(Qa+Qp)/Qp=
0.015 mg/I or 15 ug/I
306.469 mg/Kg or 306469 ug/kg
Page 1 of 1 7/17/9510:52 AM
R1)0
001 ,
'
EPA REGION IV WAI MGT PRDGRf'l1S
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t.JNlTED STATES BNVIRONMHNTAL PROTBCllON AGENCY
RHGIONIV
34S COUJln.AND STREET, N.H.
ATLANTA. GEORGIA 30365
FACSIMILE TRANSMrITAL COVHR SHBET
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Please contact the person sendtn9 thts 1btsfax {/fl ts recetvod poorly or tncomplcte.
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North Superfund Remedial Branch'
Waste Management Division
Phone Number: (404) 347-779lx 2-Df'B Pax Number: [phone]
FTS: 257·7791 . FTS: 257-1695 I
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13: 12 EPR REGION IV oh'l.MGT PROGRRMS
UNITE:D STATES l!NVIFIONMENTAL PROiECTION AGENCY
REGION IV
34!S COUR"rt..'.A.NO STREl::T, N.E:.
ATL.ANTA, C:,t::0RG1A 30365 DRAFT
Date: ,July 14, 1995
002
Subject.. Soil Remediation Levels tor Lead e.t the Potter's Pits
NP!" Site, S1;1ndy Creek, North ca,:olina ·
From: R. Bernie Hayes, Remedial Pi:-ojec::t Manager
NC Self-Directed worlc Team
'ro: l3ever1y Hudson, Remedial Proj~t Manager
NC ,9elf-dii;ected Work Teetm
As per your request, I have reviBwed the materials related to the
devGlopment of a soil ,;emediation level for leod 0t the ·Potter's
P:lte, NJ.>L Site, Included in my r'eview were tlle Remedial
Investigation report, L11e rnemo on this subject from Bill 0' Steen
dated November 19, 1991, recent .TCLP data from the Site submitted
by Bechtel, and the site Record of Decision, Now.that this
:information can be examined togethe;r:-, a more realistic soil
,-emediation level for lead in soils at the Site can be
est<>blished.
There still is not a great dee>.l of do.ta, howevei;, that we con use
£or this p~rpose, so I have in s:ome cases maae very conservative
assumptions regarding Site conditions. By doing so, any soil
remediation level that results iis li.kely to be similarl:ir
conservative, i.e., we can be fa'irly confident that ground-water
qui,.lity will be protected as a result:, l\s pan; of this
discussion I will identify those. points in the development of the
soil remediation level where dat:a !Japs resulted in th<'! use of
assumptions £or various parame.te:ro'
Bechtel provided tmalytical results for two soil samples that
were analyzed. f:or both total lead and by means of the Toxicity
Leaching Characteriglics p~-oc>edure (TCLP), TCLP is a
con~e••v<itive t.e::sl. by which a characteristic leacl1ate can be
generated and analyzed. It is used to determine wl\etl1er or not a
immple of solid waste is defined as characteristically hazardous
as defined by RCRA 1:egulations, but in this case it can be used
t.o determ.i.ne a partit;.ioning coefficient for lead in these two
soil samples. The daca provide by Bec:l!tel were:
Sample ID
U'l'-0 01-VT-O 02
EW-001-EW-00?.
Total Pb,: mg/kg
43,i.l
615.0
TCLP Pb, mg/1
NP
ND
ND ;c Not· detected at a detection· limit oE . 05 mg/1.
07/17/95 [3:13 • EPA REG I ON I u WAI MGT PROGRAMS 003
2
Since the TCLP results are 11011-di.itects, I assumed that the leachate contained lead at one-he,.lf of the detection limit, or 0.025 mg/1, in both cases, The resulting partition coefficients (!~d's) are 1,728 1/kg foi· sample UT-001-UT-002 and 24,600 1/kg for samole EW-001-F.:W-002. It: is interesting to note that the more conservative Kd, 1,728 1/kg, is very close to that derived by O',':Jteen in hi" evc,luation, which was l, 595 1/kg. Since ◊'Steen used a ve1y conservative approach as -well-, this leads to the conclusion that a Kd in this· range :i.s a conservative, realistic number to use at the Site,
The next st.ep would be to use a conservative appi--oach to estimating the impacts of soils at the Site that: exhibit this partitioning behav:l.or on und .. rlying ground waters. l used an appi:oach aimila~-lo whet is sometimes :r-eferred to as the summers model, in which inCiltrating rainwater, contaminated by the soils it passes through, mixes with the underlying-ground water flow:i.ng beneath the contaminated ar<aa. 'l'he SummG>rS approach is inherently consei:vcttive in Lhe,l. it. ossurnes no adsorption ot cont"'m:lno.nt.s either in any uncontaminated portion of the vadose zone or in the ground-waler plume.
Ground-water flow undeaneath the contaminated area of the Site wae eotimoted uainy do.to. from the Remedi61 lnvest:igation (RI) report:. Hydraulic conductivity (K) was measure by slug tests, and "n average of 2.97 x 10·• ft/s was observed. Hydraulic gradients (i) ranged from 0.03 to 0,06 across the Site/ I u:Jed the middle of the range (0.0451, Effective porosity (n) of the surficial sc,nds at t.he site was estimated to be 0,23. Using the St6ndard calculation for bulk ground-water velocity v = Ki, a <;rround-water velocity of 1. 3'1 x 10-0 ft/s is the result, This is equivalent to 422 ft/year,
Data·on the rate of infiltration of rainfall in the area were not readily available. I estimated this rate to be 12 inches per year. The are of contaminated was mea:,mres from figures in t11e IU report based on all soils cunt:{lminatecl at 10 mg/kg lead or higher (figures 5-15, 5-16, and 5-17 in the RI report). Tl1is orea was approximately 26,000 square feet. This givGJs an :i.nfiltratior1 volume of 26,000 cubic feet per yea:r-of' contaminated ro.inwatet·.
The volume o[ around-water fl.ow beneath the Site with which this contaminated inl'il.Lr:atc, will mix is estimated using the flow veloc:ity caloulo.ted cibove cmd the cross-sectional 6rea of flow in which mixing will t.alrn place. Tl1e width of the contaminated flow z;one, at right angles Lo U·,e direction of ground-water flow, is approximately 200 feet. By examining the c:r-oss-sections in the RI, the surficial sand layer in which initiol mixing will take ploce i~ about five feel thick. I estimated that mixing would take place over this entire width, giving" cross-sectional area of 1000 square feet. The ground-water flow volume ava:i.lable for
07/17/95 l3:14 • EPA REG I ON I u WAI MGT PROGRAMS 004
3
mi.xing is therefore 422,000 cubic feet per year. A dilution factor of appi:oxirnau,ly 16 (<122,000/26,000) is therefore available for mixing with contam:l.netted infiltration of raintall_,
If this dilutiou factor is applied to the oround~wat:er protection standard of 0.01.5 mg/1, a maximum concentration of 0,24 mg/1 of lead is poos:lble before the grou11d-water protection standard is exceeded. Applying the Kd calculated above to determine an allowable soil lead concentration, the result is 415 mg/kg-.
The assumptions made include:
1. Lead was present in the TCLP leachate samples at 1/2 the detection limit, ot· 0. 025 mg/1, If a more conservative approach was used, and full the detection limit used insteo.d of 1/2 the detection lirnit, the resultant soil remediation level would be halved, from 415 mg/kg to 207 mg/kg.
2. 'l'he rate of rainfall infiltration was assumed to be J.2 inche$ per year. If roinfo.11 infi_ltrotion were as high as 10 inches per year (a L·oite I would consider to be vecy high), the soil remediation level would be reduced oroportionately, from d15 mg/kg to 277 mg/kg.
The i:ernediotion level for lead in residential settings, based on the risk experienced by a child living-on the Site, is 400 mg/kg. '111is evaluation dernonslrat"s, with a reasonable degree of confidence, that; if the risk-based goal of 4.00 mg/kg of lead in $oils were u:sed for subsui:-face soils as well, ground-water protection would also be achieved. This is because the approach used is environmentally cous,.rvative in several. ways. ~·irst, the l.esg contaminated of the two so:i.1 samples was used to calculate Rd, l'\calie>tice,lly, i1;. would be accepte,ble to use any soil sample that produced non-detectable amounts of lead in the TCLP extract, such as sample EW-001-EW-002. If this sample had been th<> basis of the same calculations, the resultant soil remediatio,1 level would have been 5,900 mg/kg, Second, the Summers model does not lake into account any natural attenuation Of contaminant migrntion, which will occur in must soils to some deg-ree. Third, the use of TCLP as a meth<od by which to generate a characteristic leachate is generally considered tub~ conservative, especially for metol~, since the TCLP extract is aciditiea to a low pH. The lower pa will mobili~e mi;tals more readily than infiltrated rain water, Fourth. ths Summers rnod,al assumes 'that aquilibrium be.twGen con.taminated soils and inf:ilt.rated ground water ia reached n,pidly cu,d completely. ·since desorption kinetics tend to be much slower than adsorption rates, tl1is assumption is not lil,ely to be eiccu,~ote, and metals will be released from contaminated soils much mc,r,; slowly than predicted by this method.
My review of tlle Record of Decision (ROD) also revealed what I
. l
13:14 EPA REG I ON JU 005
4
would consider to be an oversight or error in the ROD which
should be corracLed. In the ROD, the original 3oil -excavotion
pecc.formo.nce e,tandard oC Z5 mg/kg is o1lso applied as a treatment
standard for the combined low-temperature thermal desorption and
stc1bilizat:ion process. This requir.·ernent cannot be met:. by the
LTTD/stab:Ll:lzatio11 process, since neither treatment technology
hao a e:i.gn:Lficont effect on the concenLrations of leacl in the
treeit;:ed soils. The soil excavation standard sl1ould be applied
only to that activity, regardless of whether the existing
standard of 25 mg/kg is used or if the standard is revised upward
aa a r0sult of this evalue>l:.:l.on. The perform,mce standard applied
to lc,o.d for the IJTTD/steibilization treatment process should be
based primarily on TCLP results, by requiring the 'l'CLP extract to
conform to a ground-water protection standard, or a standard with
a suitable dilution factor applied. I recommend thot. this error
be corrected in the ROD.-
Please let me know if you have any questions.
I
001
•
EPA REG I ON I lJ l,l'.1. MGT PROGRAMS
'" ~,tP,41, -~-v" ,µ-4
-" c0
~~; ~✓J
" "
UNimD STATES BNVIRO~AL PROTECTION AGENCY
REGIONIV "
345 COtnm.AND STRBBT, N.B.
A'ff.ANrA. GEORGIA 3036S
FACSJMJLE TRANSMinll COVER SHEET
1/tv/95" " __ ...
Date: TJrne: z.·~5 □ a.m. IIJ1im. / I ' /V,'i?s '7«-4-r #7il-..... TO:
" ' L~k1'LA Company/Organization: ,.Uc i;)EH/Jle..
7 ,,/
Ph~neNumber:(1't9') 7 :F~-tOf!JI, K"J:l? Fax Number, (9r~) 7":J:> -¥B/I ' . ~
Number of Pages Sent (lncludttllJ 1bls cover Shoet) , ¥
Please contact the person .rendtns this this fax if tt Is rocottJ«i poorly or tncomplete.
FROM: 2?ern,c t¼e:._e~ •
J
North Superfund Remedial Branch
Waste Management Division
Phone Number: (404) 347.n9111 2.of'B Fax Number: [phone]
PTS: 257·7791 . FTS: 257-1695
NOTES: /\/.~J .' IHtJ4cec/ ~ e-~ /,,. ~ ,&. .... ,.(,.. ,.--
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14: 18 EPA REG I ON I lJ WA. MGT PROGRAMS 002
I
UNITED STATES ENVIRON'MENTAL PROTECTION AGENCY
REGION IV
345 COURTl;_AND S"rf;tEET. N.I::.
ATI-ANTA, ~E'.ORGIA 30~6e;
Date: July 14, 1995
Subject: Soil 'Remediation Levels Car Lead at the Potter's Pits
Nl'L Site, Sandy Creek, North Carolina
From: R. Berni a Hayes, Remedial Project Memager
NC Self-D:irected Work Team
To: Beverly Hudson, Remedial Project Ma11ager"
NC self-directed Work Team
As, per your request, I have, reviewed the materials related to the
development of a so:il remediation level for lead at the Potter's
Pits NPL Site. Included in my review were the Remedial
Investigation report, the memo on tl1is subject trom Bill O'Steen
do.ted November 19, 1991, ,:·ecent 'l'CLP data from tl1e Site submitted
by Bechtel, and the S:ite Record of Decision. Now that this
information can be examined toqether, a more realistic soil
remediation level for lead in soils at the Site can be
established.
Thence still is not " great deal of data, however, that we can use
for th:is PUl-POSe, so I b1:1ve in some cases made very conservative
assumptions regarding Site conditions. , By doing so, any soi.l.
remediation level that results is likely to be similarly
conservative, i.e., we can be fairly confident that ground-water
quality will be pi·otected Ct'-' a result. A:, pa~-t of this
discussion I w:ill :identify t11ose points in the development of the
soil remediation level where data gaps resulted in t11e use of ' f . assumptions or various pc1rameters,
Bechtel provided analyticc,l nssults for two soil samples tl1at
wei:-e analyzed fo,c· both total lead and by rnecm:, of the Toxi,ci ty
Leaching Characteristics Pr·ucc,dure l'l'CLP). TCLP is a
conservntive test by which a characteristic leachate can be
geneicated and analyzed. It is used to determine whether or not a
sample of solid waste is detined as character•istically hazardous
"'" defined by RCRh re,gulo.tions, but in th;ls case it can be used
to de\:.e~;ni11e a potrtiU.oning coefficient for lead in these two
soil samples. The data provide by Becht.el were,
SamPll;) ID
UT-001-UT-002
EW-001-EW-002
Total Pb, mg/kg
43. 2
615.0
TCLP Pb, mg/1
ND
ND
ND ., Not detected at a detection limit of .05 mg/1'.
Prinlcd 0,1 l=rocycled P~pt:t
14: 18 EPA REG I ON I lJ WA. MGT PROGRAMS 003
2
Si~ the TCLP,result8 cire non-qetects, l assumed.that.the chabja contained lead at one·-half of the detection limit, or 25 .;:pg/1, in both cases_ 'l'he :resulti11g partition coefficients ( -,s1 are 1,728 1/kg for sample UT-001-tIT-002 and 2d, 600 1/kg for sample EW-001-BW-002. It is interesting to note that the more conseL·vative Kd, 1,728 1/kg, is very close to that derived by O'Steen in his evaluation, which was 1,695 1/kg, Since O'Stcen used a very conservative approach as well, this leads to the conclusion that a Kd in this range is a conservative, realir;tic number to use c;t the S.ite.
The next step would be to use a conservative approach to egtimating the impacLc1 0£ soils at the Site that exhibit this partitioning behavior on underlying ground waters, I used an approach similar to what is sometimes referred to as the Summers model, in which infiltrating rainwater, contaminated by the soils it passes through, mixes with the underlying ground water flowing beneath the contaminated area. 'rl'1e Summers approach is inherently cor,servative in that it assumes no adsorption of contarnina11Ls either in any u11contarninated portion of the vadose zone> or in the ground-water plurnei,
Ground-water flow underneath tl1e contaminated area of the Site was eotimate<l ueing data r,:om the Remedial investigation (RI) repoi:t: Hyd,·.·aulic co,,ducti vity (K) was measure by slug tests, and an average of 2. 97 x 10-4 f:t./s wc>s observed. Hydraulic gradients (i) ranged from 0.03 to 0.06 ,:;cross the Site; I used the lower end of the range (0.03), which would again be the co1>e0<ervative approach. Ettective porosity (n) of the surficial sandg at thG Site was ei'ltim<>ted to be O .23. using tl1e standard calculation for oround-s,ater ve,1¢,city V = Kiln, a ground-water velocity of 3. 87 x 10-; ft/s is the result:_ This i:s equivalent to 1,222 ft/year.
Data on the rote of infiltration ot rainrall in the rea were 10t 1~eadily available. I estimated this ro.te to be 12 inc 1es r year. The are of contaminated was measures trom figures in the RI roport based on all soils contaminated at 10 mo/kcr lead or higher (figures 5-15, 5-16, and 5-17 in the RI report), 'l'llii, area was approximately 26,000 square feet. 'I'his gives an infiltration volume 0£ 26,000 culJic feet per year of contaminated rainwater.
The volume of ground-water flow beneath the Site with which this contaminated infiltrate will mix is ·estimated using the fl.ow velocity calculc.ted cibove and c11e cross-sectional area of flow in which mixing will take ylc>ce. The width of the contc1minated flow zone, at right angles to tl1e direction of ground-water flow, is approximately 200 feel. By examining the cross-sections in the RI, the surficial sand layer in which initial mixing will take place is about five feet tl1ick. I estimated tllat mixing would take place over this entire width, giving a cross-sectional area
14: 19 • EPA REG I ON IV WA. MGT PROGRAMS 004
3
of 1000 square feet. The ground-water tlow volume avai~able for rnix:i.119 is t.herefore 1,220,000 cubic feet per year. A dilution factor o.f a1)proximate1y 47 (1, 22·0, 000/26, 000) is therefore availabl<'! for mixing with contaminated infiltration of rainfall.
lf this dil~actor is applied to the gr_ound-water protection standard o · 0.015 ,g/1, a maximum concentration of 0.71 mg/1 of l"eid is pos 'J;..l,e--lSecoL~e the grou11d-water protection standard is exceeded. Applying the Kd calculated above to determine an allowable soil lead concentral:i.oh,• the result is 1,218 mg/kg.
The assumptions made include:
1. Lead was present in t~. e i> leachate S().mples at 1/2 the detection limit, or .025 g/1. If a more conservative appro1;1ch was used, ,4-f.ui• • the detection limit used instead of 1/2 the detection limit, the resultant soil remediation level would be Jialved, t,o 509 mg/k.g.
2. The rate of rainfall infiltration wa8 aEJsumed to be 12 inches per year. If rainfall infiltration w9re as high as 18 inches per year (a rate! would consider to b9 very high), the soil remediation level would be reduced proportionately, to 406 mg/lg.
The remediation level for lead i11 residential settings, baEJed on the risk experienced by a child li,;ing oii the site, is 400 mg/kg. 'l'hj,s evaluation demonstrates, with a reasonable degree of confidence, that if the risk-based goal. ot 4.IJO mg/k.g of lead in ooils were used for :subsurface soils as well, ground-water protection would also be achieved.
My review of Lhe Record of Decision (ROD) also revealed what I would consider to be an ovei-sigllt or error in the ROD which c:hould be corrected. rn tile ROD, the original soil excavation performancE> stm,dard of 25 mg/kg· is o.lso appli.ed as a treatment standard for the combined low-te.rnperature thermal desorption and ::itobilization process. This requirement cannot be m@t by the LTTD/st;c,bilization process, since neither treatment technology has a significant effect on the concentrations ot lead in the treated l'loils. 'l'he soil excavation standard should be applied. only to that activity, ~-e9ardless of whether the existing standard of 25 mg/kg is used or if the standard is revised upward as a r.esult of this evaluation. 1'he performance standard applied to lead fol: the LTTP/stabilizatio.n treatment process should be ba:secl primarily on TCLP results I by requiring the TCLP extl·act to confor.rn to o grouncl.-wo.l.e~· protecti.on stanct,u-d, or a stanctarct with a suitable dilution factor applied. I i-ecommend that this error be corrected in the ROD.
Please let me !mow if you have ,my questions.
EPA REGION JIJ WA. MGT PROGRAMS 001
-· -~-~~;
UNI'i'ED S'rATES ENVIRONMENTAi, PROTECUON AGENCY
BEGxbNw .
34S co~ STBEET, N.E.
ATLANI'A, GEORGIA 3036S
FACSIMILE TRANSMDTAL COVER SHEET
Date: 1-/1,r /r:r Time: z"'!"To Oo.m.~-· I I Mrev {ir/4r n-1 a;,,..,, TOI
Company/Organization: Al£; V £ (i 'tJ r'?_
7 i.£.~#
Ph~ne Number: (9 f'l ) '7-:S~ -Zi"b/ Fax Number: ( 'tr"i) ?-f 5 -c.f P! I
,r-.Irf'-r . ~ ~
Number of Pages Sent (lm;/udtng Tbfs Cover Sheet) : ,
Please contact the person sending this this fax tftt ts received poorly or Incomplete.
FROM;· ·g ,',? I JI .. e!' I~ ,1·...., -, ~J .
North supeifund Remedial Branch·
Waste Management Dlvlslon
Phone Number: (404) 347•TT91 >< /l<.i<rJ' Fax Number: (404) 347•1695
l"fS: 257-TT91 -ITS: 257·1695 I
NOTES: /~'r zlf__~ 6..-~ d.,o~✓-4f <&~ li<4M'(-ff ~ . c.'£ Ve!:= 4&Y! ry -.a_,:;;{_ ~ad. 7-, r a -
' ·-
, E I
.
Date:
Subject:
To:
13:33 EPA REG I ON IV l,,ICi. MGT, PROGRt=l'IS
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
. REGION IV
346 couRTl-~ND Snun::T. N.r::.
ATLANTA, 0:EOAGIA ~036!J
ORAfl
,July 14, 1995
002
Soil Remediation Levolia for Lead at the Potter's Pits Nl'L Site, Sandy creek, North ca.rolina
R. Bernie Hayes, Remed~.·a1 Proj,F9F_~ager N'C Self-Phe,;;ted work 'ream 'jT-«:) ~
Beverly Hudson, Remedial Project Manager NC self-directed Wot-k '.I'eclm
Ac per your request, I have reviewed the materials related to the developm.,,1)t uf a soil remediation level for lead at the Potter's Pits NPL Site. Included in my review were the Remedial Investi.gation report, the memo on this subject from Bill 0 1 Steen dated November 19, 1991, recent TCLP data from the Site submitted by Bechtel, and the Site Record Of Decision. Now that this information can be exe,miued together, a more i~ealistic soil remediation level for lead in soils at the Site can be established.
There still is not a great deal of data, however, that we can use £or thil'l purpose, ::;o I. have ill sci>me cases made very conservative assumptions ,cegard:i.ng .'C::i.te cond:l.t;:Lon3. By doing so, any soil remediation level that results is likely to be similarly conservative, i.e., we can be fairly confident that ground-watt'!r quality will be prot.,,cted as a result. As part or this discusaion I will identify those;points in the development of the e,oil romedio.t.ion level whe:i:e data gaps resulted in 1:ne use of assumotions for various parameters.
Bechtel provided aualytical results for two soil samples that were analyzed for both total lead and by means of the Toxicity Leo.chi11g Che>.;u,cte,cistics Procedure (TCLP) . TCLP is a conservative Lest by which a characte~·istic lee,chate can be generated eind analyzed. It is used to deterrni11e whether or not e1 sample of solid waste is defined as chc1racteristically hazardous as defined by RCRA regulc1tions, but in this case it can be used to determine a partitioning coefficient for lead in these two soil samples. The data provide by Beclltel were,
Sample ID
U~'-0 0l-UT-002
EW-001-EW-002
Total Pb. \:oq/kg
13.2
615.0
TCLP Pb I rng/1
ND
ND
Printed Of! R(!cycled P11per
13:34 EPA REG I ON I U !&Ii MGT PROGRR"1S 003
\
ND" Not detected at a detection limit of .05 mg/J..
Since the TCLP results are non-detects, I assumed that the leachate contained lead at cine-half of the detection limit, oL-0. 25 mg/1, in both cases. The resulting partition coefficienti:: (Kd'S) are 1,728 1/kg tor sample UT-001-UT-002 and 24,600 1/kg for sample e;w-001-e;w-002. It is interesting to note that the more conservative Kd, 1,728 1/x:g·, is very close to that derived by O'Steen in his evaluatio11, which was 1,695 1/kg, Since O'Steen used a very conservative approach as well, this leads to the conclusion that a Kd in this range is a conservative, realistic number to use at the Site. ' ··
The, next step would be to use a co11servative approach to estimating the irnDacts ,:if soils at the site that exhibit tl1is partitioning behavior on underlyinQ' ground waters. I used an approach similar to what is sometimes referred to as the Summers moclel, in which infiltrating rainwater, contaminated by the soils it passes through, mixes with tt1e underlying ground Wllt.er flowing beneath the contami111;ttad area. The Summers ~pproach is inherently conservative in that i.t assumes no adsorption of contaminants either in any uncontaminated portion of the vadose zone or in the ground-water plum,:,,
Ground-water flow unde~·neo.th the contaminated area ot the Site was estimated using data from the Remedial Investigation (RI) report. Hydraulic conductivity (K) was measure by slug tests, and an average of 2. 97 x 10-4 ft/s was observed, Hydraulic gradients (i) ranged from 0.03 to 0.06 across the Site; I used the lower end of the range (0.03), which would again be the conservative approach; Effective porosity (nl oE the surticial sands at the Site was estimated tio be 0.23. Using the standard calculation for ground-water velcicity V • Ki/n, a ground-water velocity of 3.87 x 10·5 ft/sis the result. This is equivalent to 1,222 ft/year, ·
Data on the rate of infiltration ot rainfall in the are was not readily available. I estimated this rate to be 12 inches per year. .The are of contaminated was measures from figures in the RI report based on all soils contaminated at 10 mg/kg lead or higher ( figures 5-15, 5-16, and 5.-17 in the RI report) . This area was approximately 26,000 square feet. This gives an infiltration volume of 26,000 cublc feet per year of contaminated rainwater,
The volume of ground-we1ter flow beneath the Site with which this contaminated infiltrate will mJ.x is estimated using the flow velocity calculated above, and the cross-sectional area of flow in which mixing will take place. The width of the contaminated flow zone, at right a11gles to the direction of ground-water flow, is approximately 200 feet. By examining the cross-sections in the RI, the Burfici~l sand layer in which initial mixing will take
13:34 • EPA REGION !l.J WA. MGT PROGRAMS 004
place ie about 1:lve feet thick. I estimated that mixing would take placG over this entire width, giving a cross-sectional area of 1000 square feet. The ground-water fiow volume available tor mixing is therefore 1,220,000 cubic feet per year. A dilution factor of approximately 47 (l,220,000/26,000) is therefore available tor mixing with contaminated infiltration of rainfall.
If thig dilution factor i• applied to th~ ground-water protection standard of 0.15 mg/1, a maximum·concentration of 0.71 mg/1 of lead is possible before the ground-water protection standard is exceeded. Applying the Kd calculated above to determine an allowable soil lead concentration, the result is 1,218 mg/kg.
The assumptions made include,
1. Lead was present in the TCLP leachate samples at 1/2 the detection limit, or 0.25 mg/1. lf a more conservative opproo.ch wo.:s us.ed, and ru11 the detection limit used instead of l/2 ths detectio11 limit, the i:esultant soil remectiat.ion level would be halved, to 609 mg/kg,
2, The rate of r,:,.infall infiltratio11 was assumed to be 12 inches per year. If rainfall infiltration were as higb as 1B i11ehes per. yeo.:i: ( a ro.te t would c.onsiaer to be very high), thca soil remediation level would be reduced proportionately, to 406 mg/kg,
The remediation level for lead in residential settings, based on the risk ex:pe~·ieuced by a cJ·tild living ,:m the Site, is 400 mg/kg. This evaluation demonstrates, with a reasonable degree of confidence, that if tl,e risk-bas-d goal of 400 mg/kg of lead in soils were used for subsurface soils as well, ground-watGr protection would ctlso be achieved.
My review of the R<':c:or:d ol: Deciston !ROD) also revealed what I would consicle!'.' to ba an oversight or erro,-in the ROD wl1ich should be cori:ected. In tl;e ROD, 1:l~e original soil excavation performance ·standard of 25 mg/kg is also applied as a treatm<'!nt standard for the combined low-temperature thermal desorption and st"b:i.lization proc:ess, This requirement cannot be met by the LTTD/lltabili,,ation p,·oc:eas, since neitl1er treatment technology has a. siQ"nificant effect on the concentrations of leo.d in the treated :::oils. The soil excctvcttion standard should b.;, applied only to that activity, regardless of whether the exi.sting standard of 25 mg/kg is used or if the standard is revised upw,u:d ao a result of this evaluation. 'J.11e performance standard applied to lead £or the LTTD/stabilization trec,trnent process should be based primarily on TCLP results, by requiring the TCLP extract to conform to a ground-wal:.ei· protection standard, or a standard with a suitable dilution factor appliecl. I recommend that this error be corrected in the ROD,
13:35 EPA REGION IU ij'l.MGT PROGRAMS 005
4
Please let me know if you have any que:,t:ions.
I
EPA REG I ON I tJ w:11 MGT PROGRf'l'IS 001
' ~· .. ~ -· ~i .
UNrrHD STATES ENVmONMENfAL PROTECfiON AGENCY
lmGIONIV ' '
34S COURn.A~ STRRRT1 N.E.
ATLANTA, GEORGIA 30365
FACSIMILE TRANSMlTIAL COVER SBBRT
1/2.;/tr~ --~ Date: Time: .z :t/5 □ a.m. li}Jf.m. ( I
T01 ;V,'i?s -;T;;-,f,... -7"-,.._
Company/Organization: ,Uc DEHN~ i:t?..k,iJ:
7 .,I
Phone Number, (1r<1) 1-,::;-z09;_ r3.2f Fax Number. (91¢) :/-~'!> -1/B//
' . ~
Number of Pages Sent (Jncludtng Tbfs Cowr Sheet) : ¥
Please contact the pt,,;on sendtng thfs tbts /ax '.fit ts roc(lfved poorly or ,ncomplete.
FROM:· ti' ern, ·e r¼re" , .
Nonh Superfund Remedial Branch .
Waste Management Dlvlslon
Phone Number: ( 404) 347-779'1 K ZOfE{? Fax Number: [phone]
l'TS: 257-7791 . PTS: 257-1695 i
NOTES: 1--I:?, .. Fno,,t-_c/ ~~ ~I-YUY.r /,. /£ .,.._,,,,.. ,{~ r
~d,..-,:'> e>').--,-: ,!;" .. ..ri:::: /4v ,,£, . l?m t k,,,. . 41.--:Z:.;...,
;{__ 7 I
7~
$4: ~ ~~-,
d,,."" I+!:
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1
'
Date:
Subject:
From•
To:
13:46 EPA REG I ON IV i,Jl. MGT PROGRAMS
I
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
RE.(;ION IV
34t, COURTLr,No STRC.E.Y, N.E.
ATl-ANTA. GEORGIA :l0365
July 14, 1995
002
Soil ·Remediat.iu11 Levels for Leed et the Potter's Pits
NPL Site, Sandy Creek, North Caroli11a
R. ·Bernie m,ye:,, Remedial Project Manage~-
NC Self-Directed Work Team
Bevei-ly Hudson, Remedial Project Manager·~
NC Self-directed Work Team
As. ))er your request, "C have reviewed the materials related to the
development o( a soil remediation level for lead at the Potter" s
Pits Nl?L Site. Included in my review were the Remedial
Investigation i-epot't, the memo on this subject from Bill O'Steen
doted Nov.,rnbe,,· 19, 1991, :i:-ecenc TCLP data from the site submitted
by Bechtel, <1nd the Site Record of Decision. Now that this
infonnation can be examined together, a more realistic soil
remediation level for lead in soils at the Site can be
established.
There still is not. a gn,ttt. deo.l of do.to., however, tho.t we co.n use
for this purposE:, so I h1;tve in sorne case$ made ve1.y conservative
assumptions regarding Site conditions. By doing so, any soil
rem«diation level that results is likely to be similarly
conservative, i.e., we can be fc,irly confident that g2:uund-water
quality will be l?rotec\:.ed cu5 " ~-esult. A:s part of this
discussion I will identify those points in the development of the
soil. remediation level whe,~e data gaps resulted in the use of
assumptions for various parameters.
Bechtel provided analytical resu1ts for two soil samples that
were analy~ed fen:· .both total leo.d and by means of the Toxicit:y
Leaching CharacLerisLic.:s P,:·occ,adurs (TCLP) . TCLP is "
conservative test by which " chcu·«cteristic let11..:ltttte can be
generated and e,neil.yzed. It is used to determine whether or not ct
sample of solid waste is defined as characterisU.cally hazardous
""' clefiw,cl !Jy RCRA r:egulations, but in this case it can be used
to determine a pt.rtitio,,i,,g coefficie11t for lead :i.n these two
soil samples. The data provide by Bechtel were,
Sctmple IP
UT-001-UT-002
EW-001-EW-002
Total Pb, mgt'.kg
43.2
615'.0
TCLP Pb, mg/1
ND
ND
ND " Not detected at a detection limit of .05 mg/1".
Ptirtlcd on Recycled f'11p1Jr
13:47 EPA REG I ON IV WA. MGT PROGRAMS 003
2
si~ the 'l'CLP results are non-detects, I assumed that the i/
1 J.--eac~a contained le,ctd b.t one-half of the detection limit, or f...& /:P.~. 1/L
0;?,5 /l, in both casea. The resulting partition coefficients 7FJ
a·•·s are 1,728 1/kg for sample UT-001-U'I'-002 and 24,600 l/kg
£or sample EW-001-EW-002. lt is interesting to note that the
more conservative Kd, 1,728 1/kg, is very close to that derived
by O'Steen in his evaluation, which was 1,695 l/K:g. Since
O'Steen uaed a very conee;i;·vo.ti.ve o.pproach as well, this leads to
the conclu$ion that.:. ct J<:d :Ln this range is a conservative,
:nc:alistic number to use at Lhe Si Le.
The next step would be to use a conservative cJ.pproach to
eotimati1ig the impact:s of soils at tile Site chac exhibit tnis
partid.on:i.,,g behavior on underlying ground waters. I used an
approach similar to what is sometimes referr,;,d to as the Summars
model, in which infiltrating rainwater, contaminated by the soils
it passes through, mix.es with the underlying ground water flowing
beneath the contaminated area. 'l'J1e summers approach is
inhere11tly conse,.ovative in LhaL it ,u,sumes no adsorption ot
co11taminants either :i.n any uncontaminated portion of the vadose
zone or in the ground-water plume.
Ground·-water flow underneath the contaminated 1;1rea of the site
we,s estirno.t"'d using data from t.t1e Remedi1;1l Investigation (RI)
report: Hydraulic conductivity IK) was measure by slug t:ests,
and an average of 2. 97 x 10-• ft/s was observed. Hydraulic
gradients (i) ranged from 0.03 to 0.06 across the Site; I used
the lower end of the range (0.03), which would again be the
conseJcvative app1.·oc0d1. Effective porosity (n) of the surticial
sa11do at the Sito wos est;irnate,d to be O, 23. using the standard )-3
calculati.011 for ground-water veloc;iLy v ~ Ki/n, a ground-water I') ' -S'JII.
velocity of 3.87 x 10·'· ft/s is the result. 'l'his is equivalent.
3
c;,:,-f.tD vrS
to. 1,222 ft/year. .. ·· ..... ·-. V°' '
Dcita. on the n,te of infiltration of rainra11 in urn4,rha 1ver~1ot .
readily available. I e$time1ted this rate to be 12 inc es-·i7er ~a),rC,
year. The an, of conLarnindtred was measures from figures in the p
RI repoi:t based on all soils contaminated at 10 mg/kg lead or -
higher (f:igures 5-15, 5-16, and 5-17 in the Rl fej;iort). This /
area was approxirntitely 26,000 square feet. This gives an
infilt:re,tion volume of 26,000 cubic feet per year or contaminated
rainwater.
The volume of ground-we1ter flow beneath the Site with which this
contaminated infiJ.L:C'cJ.te will mix is estimated using the flow
vel.od.ty calculated al:,ove and Llie cross-sectional area of flow in
which mixing will t.ake pleH;e, The width ot tl,e contaminatecl [low
zone, at i~ight angles l.:o the direction o( ground-water flow, is
approximately 200 feet. By exc1mining the cross-sections in the a-
RI, the surf:i.cial sand layer in which initial mixing will take · W
place is about five feet thick. .I estimated that mixing would
take plo.ce ov-er thio: ent.ire widt:.b, giving a. cross-sectional area
• 13:47 EPA REG I ON IV WAI MGT PROGRA"IS 004
3
of 1000 square feet. The ground~water flow volume available for
mixing is therefore 1,220,000 cubic feet per year. A dilution
factor o.!' e.pp;i;·oximately 47 (1,220,000/26,000/ is therefore
available for mixing wit:h contam:\.n.ated infilt:ration of rainfall.
If this di~-fu11ctor is applied to the ground-water protection _,,-/.
standard o · 0.015 tg/1, a maximum concentration of 0.71 mg/1 of _,-(
leo.d i:, po" 'cl,¾<, e[ore the yi·ound-wat.er protection standard is1 )'R ~ _,f!P
exceeded. Applying the Kd calculated above to determine an ~~~
allowable soil lead concentration, the result is l, 218 mg/kg_ 1.::2,S-
The assumptions made include:·
l. Lead we.a p,:·esent in t]~P leaclrn.te samplea o.t 1/2 the
detection limit, or(l'.i.025 rgsi/1. If a more conservative
approach was used, aBQ-f-H·ll the detection limit used instead
of 1/2 the detection limit, the x·esultant soil remediation
level would be halved, to 609 mg/kg.
2. '!'be ,:-ate 0£ ra:i.i,fall i11filt:t'at:.:lon wa,:, a,:,o,umed to be 12
inches per year. If .rainfc,11 iafiltr:al:ion were as high as
18 inches per year (a rate I would considex-Lo be vety
high), the soil remediation level would be reduced
proportionately, to 40G mg/kg. --=----
The 1:-emediation level for lead in r:~i;;.:i.dt?u.tial 1::H~ttings, based on
the risk experienced by a child living on the Site, is 400 mg/kg.
This evalueit:i.on demonstrates, with a ,:e,H!Onable degree of
confidence, that if the risk-based goal of 400 mg/kg of lead in
soils were used for subsurface soils as well, ground-water
pl'.'otection would also be achieved.
My review of the Record of Decision (ROD) also revealed what J.
would consider to be an oversight or error in the ROD which
should be cor:L"ected. In the ROD, the original soil excavation
perfoi:mancc: :stando.rd of 25 rng/ky is also applied o.s a treatment:
standard to,:· the combined low-te.mperatui·e thermal de,;o,:ption nnd
sto.bil.ization process. This requirement cannoL be met by the
L't''t'D/stabili2:ettion process, sincEi neiLhe,--lTeaLmeut technology
has a significant effect on Lhe cv1H.:eutratiuns of lead in the
treated soils. Tile soil excavation standard should be applied
only to th-,1; acl:ivity, re90.rdless of whether the existing
standar·d of 25 mg/kg is used or if the st:andard is revised upwar'd
as a resulL of this evaluation. The performance standard applied
to lead for the LTTD/stc1bil.i:rnt.ion. treatment process should be
based primat-ily on TCLP results, by :r·equiring the TCLP extract to
conform to a g,:ound-waLe1c-pLutectiuu st:a.ndarcl, 01: a standard wit.11
a suitable dilution factor applie.cl. l i:·ecummend that thiB error
be corrected in the ROD.
Please let me know if you have any que:stions.
• •
September 6, 1994
MEMORANDUM
TO:
From:
RE:
Jack Butler, NC Superfund
Randy McElveen, NC Superfund
Budget Summary/Clean-up Costs
Potter's Septic Tank Service Pits
NCD 981 023 260
Record of Decision (ROD) June 1992, remedies for soil and
groundwater
-Soil Remedy:
Present Worth Cost:
-Groundwater Remedy:
Present Worth Cost:
Low Temperature Thermal Desorption
(10,100 cubic yards)
$4,700,000
Air Stripping for removal of
Volatiles and Chemical Treatment
(Precipitation, Flocculation, and
Filtration) for Metals removal.
$5,300,000 (Based on a clean-up
standard of 5 ug/L Benzene)
-Record of Decision (ROD) contingency remedy for soil:
Off-Site Disposal (Landfill or Incinerate based on TCLP
results) 10,100 cubic yards
Present Worth Cost: $8,100,000
The June 1992 ROD states that the groundwater treatment remedy is
a pump and treat remedy including air stripping in conjunction
with chemical treatment. The clean-up of the groundwater to the
performance standards is projected to take approximately 13
years. The pump and treat remedy will include approximately 6
pumping wells at 10 gpm for a total pumping rate of 60 gpm. The
cost estimate for annual operation and maintenance (O&M) of the
pump and treat system is $479,000 during operation and $77,000
after operation during the 5 year review periods.
Mr. Butler
9-6-94
Page 2
• •
The Feasibility study did not include low temperature thermal
desorption as a remedy for soil but included it as part of the
incineration/thermal treatment alternative. The cost of on-site
thermal treatment in the Feasibility Study is $12,400,000.
(I\ Sllt,i I OW !Jflt-Hl()RIN(; Wf"l /
{',:) ll!fl' !.H!tlllORlflG W[ll.
• PROr>oS{o~:'r1rcovrny wi u. . :;,, . •' -··-~~.
APPfWXIMAlE [Xlfl/1 Of
lOIAL VOC's (IUuy/t),
MARCH, 1990 'Un
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Ill Ill
,., ··202
SIJJULAl[D CP.PTUR[ ZONE
60 GPtJ
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(Appro)(. 600')
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MW-· l~l-i
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Slf..llll.Al[D CROUHDWATER CAPlURE
zor~[. \N Ill[ UPPER AQUIFER, ..§,0 Cf'µ_ Rob_________ --
r-Y&1tttH'Y'-"s11Tu-Y-roR TIIE POT I EHS
SEPTIC T At<K SERVICE PITS Sil [
SAN[)Y CH[[K, fWRlll CAROLHH
.IC
I
State of North Arolina
Department omivironment,
Health and Natural Resources
Division of Solid Waste Management
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
March· 25, 1994
MEMORANDUM
TO:
FROM:
RE:
File
Randy McElveen
Environmental Engineer
NC Superfund Section
Variance From Groundwater Standards for Benzene
Potter's Septic Tank Service Pits NPL Site
Located in Brunswick County, North Carolina
NCO 981 023 260
On the above date Beverly Hudson, EPA Region IV contacted me
to set-up a conference call between EPA and the Superfund Section
to discuss the procedure for obtaining a variance from the NC
Groundwater Standards for Benzene, Ethylbenzene and Naphthalene as
established in the Record of Decision (ROD) for the Potter's Pits
NPL Site. Rolando Baskin, the EPA attorney for the subject site,
Beverly Hudson and myself participated in the call.
Generally, we discussed who needed to be contacted and what
information was needed in order to begin the process. I
recommended that they contact Mr. Preston Howard the Director for
the NC DEM Groundwater Section in order to request detailed
instructions for obtaining the requested variances and that proper
notification be forwarded to the Superfund Section as appropriate.
This request resulted from the NC Superfund comment letter dated
January 6, 1994 and as a result of the meeting between the NC
Superfund Section and EPA, on March 9, 1994. See the Memo to File
for the meeting dated March 10, 1994.
During the conference call the NCAC Title 15, 2L Groundwater
Standards were provided for Benzene (1 ppb), Ethylbenzene (29 ppb)
and the proposed standard for Naphthalene (24 ppb).
cc: Jack Butler, Superfund Section
Beverly Hudson, EPA Region IV
P.O. Box 27687. Raleigh. North Carolina 27611-7687 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ l 0% post-consumer paper
... ,. • •
State of North Carolina
Department of Environment, Health, and Natural Resources
Division of Solid Waste Management
P.O. Box 27687 · Raleigh, Notih Carolina 27611-7687
James G. Martin: Ciovcrnor
William W. Cobey, .Jr., Secretary
Ms. Darcy Duin
Remedial Project Manager
US EPA Region IV
345 Courtland Street, NE
Atlanta, Georgia 30365
Dear Ms. Duin:
August 28, 1992
\\'illicci L Mc,·cr
Director
RE: Potter's Septic Tank Service Pits \PL Site
Maco, Brunswick County
The North Carolina Division of Environmental Management has sent the attached 2dditional
comments on the Potter's Pits Record of Decision. Many of the comments have alre;0 dy been
addressed. The remaining comments could probably be addressed in the site remedd design
phase. Please let me know if you have any questions regarding these comments.
CVJ/slb
Attachment
Sincerely,
/ I I /--:-I . I.. vf u .. z.,·(,-v<__'-'-).,'-----'---, '--'---·-· -
I
Charlotte V. Jesneck, Head
Inactive Hazardous Sites Branch
Superfund Section
An Equal Opportunity Affinnc.1tive Action Employer
••
State of North Carolina
.. n 1-vi.... 1 ~ ... -
AUG 2 G 1992
Department of Environment, Health and Natural Resources
Division of Environmental Management
512 North Sali:;bury Street• Raleigh, Nonh Carolina 27604
Janie~ G. i\1anin, Governor
\Villiam W. C(}bcy, Jr., Secn.::.t.:.iry August 14, 1992
A. Preston Howard, Jr., P.E.
Acting Director
Ashc•;illc
·.1n/+/2:i 1-Ci2C.::
rayctte,,.iilc
TO:
FROM:
,19;4:,6-1.141 SUBJECT:
Jack Butler, Special Projects Branch Head
A. Preston Howard, Jr. P.E.44)
Potters Septic Tank Service
Mon;esvillc
70/4/663-1699
Ralcith
919;57 J. .,r;oc
Washington
919/946-648 l
Wilmington
919/395-3900
91 :J/896-7007
Draft Recorcoof Decision
Brunswick County
Project #92-37
As requested, the Division of Environmental
Management has reviewed the subject document. The
comments from our Water Quality, Air Quality and
Groundwater sections are provided below:
Air Quality Section Comments
The selected remedy includes air stripping.
Volatile organic emissions are estimated to be less than
30 pounds per day. No emission control is required.
Since no air-cleaning device is proposed, an air permit
is not required.
The air stripper must be registered with the
Material presented in the Record of Decision
TABLE 29, DIAGRAMS, DISCUSSION, ETC]
meets registration requirements for the
Division.
[TABLE 28,
sufficiently
project.
The Air Quality Section requests permission to copy
parts of the Record of Decision and to be allowed to
place this information on file. If this request is
granted, the information on file will be available to the
public. In the alternative, the following information
must be submitted to the Division and will be available
to the public;
name of operating source
principal company contact
,Pollution J'revention Pays
P.O. Box 29535, Raleigh, Nor-Ji Carolina 27626--0535 Telephone [phone]
An Equal Opportunity Affirmative Action Employer
•• ..
location of source [ADDRESS]
site diagram which shows streams, roads, homes,
buildings
description of process
total air flow -stack height -fuels used
total weight and kind of air pollution
released
calculations used to determine daily emissions
acceptance of requirement to notify DEM in
event emissions increase (above stated values)
length of time remediation activities will last
This information should be sent to the Wilmington
Regional Office and questions concerning registration may
be directed to John Anderson at [phone].
Water Quality Section Comments
It appears that a NPDES permit will be required. No
other comments at this time, other than those previously
expressed in review of previous reports.
Groundwater Section Comments
The selected remedial actions for soil and
groundwater reclamation appear satisfactory. However,
the cleanup standards for napthalene and benzene in
groundwater are not consistent with 2L standards.
Benzene will be treated to a concentration of 5 parts per
billion (ppb), and napthalene to 30 ppb. We are unsure
as to whether the cleanup standards listed above would
satisfy the health-based concerns for the state
toxicologists.
Also, further assessment of groundwater
contamination (benzene at 58 ug/1) found in a deeper well
is mentioned on page 106. We suggest that additional
moni taring wells be installed to assess the extent of
this contamination, and that cleanup of this area is
made.
•• ..
Thank you for the opportunity to review the subject
document. Should you have questions or wish additional
discussion on this matter, please contact, Mr. Rick
Shiver at [phone].
cc: Perry Nelson
Steve Tedder
Alen Klimek
Rick Shiver
Nargis Toma
NT/pkh:Potters.drf
.. ..
State of North Carolina
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
FAX TRANSMITTAL RECORD
DATE:
William L. Meyer
Director
FROM: ___________ , Solid Waste Management Division
___________ , Solid Waste Section
___________ , Hazardous Waste Section
, Superfund Section
TO:
RE: /. '. c:c· 1/ I ',
:'lumber of pages (ir\cluding cover)
Confirm receipt of document(s):
Division of Solid Waste Management
Solid Waste Section
Hazardous \Vaste Section
Superfunc! Section
[phone]
[phone]
[phone]
[phone]
An Equal Opportunity Affirm.a.rive Action Emp!oyer
--. ,. • • t<E.Ct\VtO
AUG 2 G 1992
SUPERIDIID moN
State of North Carolina
Department of Environment, Health and Natural Resources
Division of Environmental Management
512 North Salisbury Street• Raleigh, North Carolina 27604
James G. Martin, Governor
William W. Cobey, Jr., Secretary August 14, 1992
A. Preston Howard, Jr., P.E.
Acting Director
Regional Offices
Asheville
704/251-6208
Fayetteville
TO:
FROM:
919/486-1541 SUBJECT:
Jack Butler, Special Projects Branch Head
A. Preston Howard, Jr. P.E.~
Potters Septic Tank Service
Mooresville
704/663-1699
Raleigh
919/571-4700
Washington
919/946-6481
Draft Record of Decision
Brunswick County
Project #92-37
As requested, the Division of Environmental
Management has reviewed the subject document. The
comments from our Water Quality, Air Quality and
Groundwater sections are provided below:
Wilmington Air Ouali ty Section Comments
919/395-3900
Winston-Salem
919/896-7007
The selected remedy includes air stripping.
Volatile organic emissions are estimated to be less than
30 pounds per day. No emission control is required.
Since no air-cleaning device is proposed, an air permit
is not required.
The air stripper must be registered with the
Di vision. Material presented in the Record of Decision
[TABLE 28, TABLE 29, DIAGRAMS, DISCUSSION, ETC]
sufficiently meets registration requirements for the
project.
The Air Quality Section requests permission to copy
parts of the Record of Decision and to be allowed to
place this information on file. If this request is
granted, the information on file will be available to the
public. In the alternative, the following information
must be submitted to the Division and will be available
to the public;
name of operating source
principal company contact
Pollution Prtvention Pays
P.O. Box 29535, Raleigh, Nonh Carolina 27626-0535 Telephone [phone]
An Equal Opportunity Affirmative Action Employer
• •
location of source [ADDRESS]
site diagram which shows streams, roads, homes,
buildings
description of process
total air flow -stack height -fuels used
total weight and kind of air pollution
released
calculations used to determine daily emissions
acceptance of requirement to notify DEM in
event emissions increase (above stated values)
length of time remediation activities will last
This information should be sent to the Wilmington
Regional Office and questions concerning registration may
be directed to John Anderson at [phone].
Water Quality Section Comments
It appears that a NPDES permit will be required. No
other comments at this time, other than those previously
expressed in review of previous reports.
Groundwater Section Comments
The selected remedial actions for soil and
groundwater reclamation appear satisfactory. However,
the cleanup standards for napthalene and benzene in
groundwater are not consistent with 2L standards.
Benzene will be treated to a concentration of 5 parts per
billion (ppb), and napthalene to 30 ppb. We are unsure
as to whether the cleanup standards listed above would
satisfy the health-based concerns for the state
toxicologists.
Also, further assessment of groundwater
contamination (benzene at 58 ug/1) found in a deeper well
is mentioned on page 1 06. We suggest that additional
monitoring wells be installed to assess the extent of
this contamination, and that cleanup of this area is
made.
• •
Thank you for the opportunity to
document. Should you have questions
discussion on this matter, please
Shiver at [phone].
cc: Perry Nelson
Steve Tedder
Alen Klimek
Rick Shiver
Nargis Toma
NT/pkh:Potters.drf
review the subject
or wish additional
contact, Mr. Rick
• • UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IV
4WD-NSRB
July 30, 1992
Charlotte Jesneck
345 COURTLAND STREET. N.E.
ATLANTA. GEORGIA 30365
North Carolina Department of Environment,
Health, and Natural Resources
401 Oberlin Road, Suite 150
Raleigh, North Carolina 27605
NfcrE:~~tt:,f!J
AUG O 3 1992
SUPERRJND SECnoPI
RE: Response to Conditions Included in North Carolina's
Conditional Concurrence for the Potter's Septic Tank
Pits Superfund Site Record of Decision
Dear Ms. Jesneck:
EPA-Region IV appreciates the State's conditional concurrence on
the Record of Decision (ROD) for the Potter's Septic Tank Service
Pits Superfund site located in Sandy Creek, North Carolina. For
the record, EPA would like to respond to the conditions formulated
by North Carolina Department of Environment, Health and Natural
Resources (NCDEHNR) -Superfund Section and specified in your
July 29, 1992 correspondence to Mr. Greer Tidwell. Your July 29,
1992 letter, along with this response, will be included in Appendix
I of the ROD. These letters should stand as official documentation
that EPA-Region IV and NCDEHNR-Superfund Section have agreed on the
preferred alternatives at this point in time.
Of the four conditions expressed, only the first condition requires
a response from the Agency. In response to NCDEHNR-Superfund
Section first condition, the State may in the future put in place,
pursuant to ,State law (G.S. 130A-310.8), a deed recordation /
restriction to document the presence of residual contamination
which may limit the future use of the property. As stated, this
would be done after the completion of the site's remediation.
Please contact me at [phone] if you have any questions or
comments regarding this matter.
M,rely,
Dar~
Remedial Project Manager
cc: Curt Fehn, EPA
Printed on Recycled Paper
• • UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IV KE.Glr:.\VtU
345 COURTLAND STREET. N.E r,u G O.., '992
ATLANTA. GEORGIA 30365 r, tJ I
4WD-NSRB
July 29, 1992
Charlotte Jesneck
NCDEHNR
Superfund Section
401 Oberlin Road
Raleigh, North Carolina 27605
suemruf4D StC1WN
RE: Response to N.C. Comments on the Draft RI Addendum and
Feasibility Study Reports
Potter's Septic Tank Service Pits Site
Sandy Creek, North Carolina
Dear Ms. Jesneck:
Listed below is a response to North Carolina's comments on the
first and second (final) drafts of the RI Addendum and Feasibility
Study Reports.
FIRST DRAFT OF THE RI ADDENDUM
As you are aware the first draft of the RI Addendum was sent for
the State review on December 17, 1991. Comments were received from
North Carolina on January 8, 1992. Several weeks later a
conference call occurred between EPA and North Carolina State
(Darcy Duin, Curt Fehn, Bill O'Steen; Charlotte Jesneck, and Lee
Crosby were in attendance) to discuss comments on the RI Addednum
and the Feasibility Study. At that time I believe we came to an
agreement on how all three comments would be addressed and have
listed the response below. These comments, if needed, were
addressed in the second Draft of the RI Addendum.
COMMENT #1:
Page 2-7 of the 1990 Draft Remedial Investigation Report indicates
oil was released to Chinnis Branch and Rattlesnake Branch in 1976.
Surface water and sediment samples have been collected from Chinnis
Branch, but none from Rattlesnake Branch. Samples should also be
collected from Rattlesnake Branch.
RESPONSE:
As discussed in the conference call (it was our (Bill, Curt, Darcy)
understanding that we (N.C. and EPA) all agreed), since Rattlesnake
Branch is too far away from the site to attribute any contamination
that might be found there to Potter's Pits, sampling would not be
appropriate. EPA is aware of the 1976 oil spill that occurred at
Printed on Recycled Paper
• •
Potter's which sent contamination down to Rattlesnake Branch;
however since 16 years have gone by since the spill, it would be
difficult to trace the contamination back to Potter's especially
enlight of the fact that the contaminants of concern are the common
BTEX constituents which are used in a variety of manufacturing and
domestic uses. (This comment is identical to response to comment #6
from the Draft ROD).
COMMENT #2:
The SS-46 area requires additional investigation to determine the
extent of contamination towards Chinnis Branch.
RESPONSE:
This comment was discussed in length during the conference call.
It was determined that N.C. was missing some of the tables of the
soil data from the original RI. These were subsequently sent to
the State and hopefully this issue has been resolved. It is EPA's
belief that the extent of contamination toward Chinnis Branch has
been fairly well defined; however, soil sampling may be needed
during the design phase to better locate the exact location and
amount of soil which needs to be remediated. This is outlined in
the ROD.
COMMENT #3:
Only two borings were conducted and only one surface soil sample
was collected in Area 3. Additional sampling will be necessary to
adequately charactrize Area 3.
RESPONSE:
During the conference call it was decided that possibly during the
design phase another sample from Area 3 could be taken. As stated
in response to comment #5 for the Draft ROD, a sentence will be
incorporated in the ROD to verify the fact that another sample will
be taken in Area 3. The sentence will read, "Since limited
sampling was conducted in Area 3 during the Remedial Investigation,
a soil boring will be installed near MW-104 and samples collected
by compositing 2.5 foot intervals continuously to 12.5 feet below
ground surface ( 5 samples) . These samples will have a complete
TCL/TAL analyses performed." This sentence will be added in
Section 9.2 of the ROD.
SECOND DRAFT OF THE RI ADDENDUM
The second Draft of the RI addendum was Federal Expressed to you on.
J"7 April 8, 1992. Comments were received from the State on May 26,
lr,/ 1992 on the RI Addendum and the Feasibility Study Reports. The ~c,vC comment and EPA's response is listed below. y /o/ctd--
• •
COMMENT #1:
Monitoring wells located at the northern and southern extent of the
groundwater contaminant plume have exhibited concentrations of
contaminants slightly above cleanup goals. Additional monitoring
wells may be necessary in these locations if the concentrations in
the outer-most wells do not immediately drop below cleanup goals at
the commencement of groundwater remedial action.
RESPONSE:
All of the monitoring wells will be sampled again during the design
phase and the necessity of additional wells will be continually
evaluated before design and after the remedial action has begun to
determine the effectiveness of the system. Additional wells can be
added at any point of the process when they are determined to be
necessary.
Included as Attachment #1 is the changes that were made on the
second Draft of the RI Addendum. Since there were few changes to
this draft, only the revised pages were sent. Please substitute
these pages in the second draft which is the final RI Addendum.
FIRST DRAFT OF THE FE~SIBILITY STUDY REPORT -f.
I:; Pk \/Jo.._,s no~ if,<.J of tkc.. o\e.la~ ,·" ( o,li"l)'Y>t,t '~~ o 11
The first draft of the Feasibility Study Report was sent to the
State on December 23, 199~. Comments were due on this document on
January 10, 1992. Comments were received from the State on January
28, 1992. Below is listed all of the State's comments with EPA's
response. Again all of these comments were discussed in the
conference call referred to above between EPA and N.C. State.
COMMENT #1:
Section 1, page 11 indicates Area 3 is not considered an area of
concern. Since contamination was detected in at least 1 of only 2
samples collected in the area, additional sampling should be
conducted before the area is deemed not an area of concern.
RESPONSE:
Please refer to response to comment #3 above.
COMMENT #2:
Section 1, page 11 indicates the extent of soil contamination is
limited to the upper 15 feet of the overburden. Since the deepest
samples in this area were contaminated, the vertical extent of soil
contamination has not been defined. The vertical assessment of
contamination should extend to the depth of the seasonal low water
table.
L_ __ _
• •
RESPONSE:
Sampling will be done in
contamination has not been
identify the exact locations
be excavated and treated.
areas where the extent of soil
defined during the design phase to
and amount of soil which will need to
COMMENT #3:
Table 3-1 should read the "North Carolina Drinking Water Act"
rather than the "North Carolina Safe Drinking Water Act." Table 3-
1 should also include the North Carolina Water and Air Resources
Law, the North Well Construction Act, the North Sedimentation
Pollution Control Act, and all rules developed in conjunction with
each state environmental law.
RESPONSE:
In Table 3-1, "North Carolina Safe Drinking Water Act" has been
changed to "North Carolina Drinking Water Act (General Statutes of
NC,Chapter 143) ". Also, the following have been added:
*
*
*
*
*
*
*
North Carolina Water and Air Resources Law (General Statutes
of NC, Chapter 143)
North Carolina Water Pollution Control Regulations (NCAC Title
15A, Chapter 2)
North Carolina Air Pollution Control Laws (General Statutes of
NC, Chapter 143)
North Carolina Water Quality Standards (NCAC Title 15A,
Chapter 2, Subchapter 2C)
North Carolina Drinking Water and Groundwater Standards (NCAC
Title 15A, Chapter 2, Subchapter 2C).
North Carolina Well Construction Act
North Carolina Sedimentation Pollution Control Act (General
Statutes of NC, Chapter 113A)
COMMENT #4:
The table provided in Section 5, page 10 indicates that a
treatability study would be required for thermoplastic
stabilization. All of the stabilization processes would have to be
tested at site conditions to determine effectiveness.
RESPONSE:
The text in Section 5 (page 5-10) as been modified to reflect that
• •
all retained stabilization processes "would require treatability
studies."
COMMENT #5:
The capping alternative outlined in Section
practically maintained on a piece of residential
the option alone does not decrease the toxicity
waste and may not decrease mobility.
RESPONSE:
5 could ·not be
property. Also,
or volume of the
We agree that the capping alternative would be difficult to
maintain on an occupied residential property. In accordance with
the comment, institutional measures which were previously included
in Alternative 6 have been emphasized pertaining to relocation of
the residents and dwelling.
With respect to the issue of mobilty of contaminants, a properly
designed, installed, and maintained cap will effectively reduce
mobility by limiting infiltration of precipitation.
COMMENT #6:
Section 5, page 34 indicates carbon absorption will not be retained
as a treatment process option, yet air stripping will. Air
stripping will only serve to remove volatile organic compounds
where Henry's Law applies. Metals and semi-volatile compounds
would not be addressed.
RESPONSE:
Although carbon adsorption is potentially applicable to the site,
it is not expected to be a cost-effective technology when compared
with other retained process options that when implemented in
conjunction with each other, can treat all contaminants encountered
at the site; therefore, this process option will not be retained
for further consideration.
COMMENT #7:
Section 6, page 3 indicates groundwater will be treated to MCLs.
The North Carolina Groundwater Quality Standards (Title 15A NCAC
Subchapter 2L Sections .0100, .0200, and .0300) should also be used
as treatment goals.
RESPONSE:
The last sentence in Section 6.2.2 has been changed to read as "The
ultimate goal of remediation will be to meet ARARs and health based
numbers in the groundwater." Also be aware that Table 3-3 has been
modified to include NCAC Title 15A, Chapter 2, Subchapters 2L.0100,
2L.0200, 2L.0300 as ARARs.
• •
COMMENT #8:
The method of mixing proposed for soil stabilization in Section 7,
page 39 may not provide effective blending of the stabilization
agent with the waste. Other methods of mixing should be evaluated
if this alternative is selected.
RESPONSE:
The paragraph on page 7-39 will be modified to point out that the
described process is an example of a mixing techniques used for in-
situ stabilization/solidification.
COMMENT #9:
Additional investigation should be planned for Area 2. Individuals
involved in the earlier removal should be contacted to locate the
area. Geophysical methods should be employed in suspect locations
followed by soil borings.
RESPONSE:
As discussed in length during the conference call, EPA believes
that all efforts have been made to locate Area 2. Without better
historical data to the exact location of Area 2, soil borings would
be an expensive method to try and locate this area. As discussed
in the RI, every effort was made to talk to anyone who might have
knowledge of the location. Please note that in Section 5.1 of the
ROD this has also been described.
COMMENT #10:
Page 3-4 states that 80 soil borings were completed within Area 1
and 3 (78 for Area 1 and 2 for Area 3 I . Additional soil sampling
should be conducted in Area 3 in order to accurately assess the
risk from Area 3 soil exposure. In addition, a more thorough
groundwater sampling should be conducted in area 3 in order to
accurately assess the risk from groundwater exposure.
RESPONSE:
Please refer to response to comment #1 above.
COMMENT #11:
A list of the individual carcinogens and noncarcinogens should be
provided in table format showing how the risk and hazard quotients,
respectively, were calculated. In addition, reference doses and
slope factors used in the risk assessment should be provided.
RESPONSE:
Table 1-3 and
significantly
1-4
to
list the
carcinogenic
chemicals contributing
and non-carcinogenic
most
risk
• •
respectively. Supporting documentation was provided in Section 7
(Public Health Baseline Risk Assessment), Appendix h (Dose Response
Values), and Appendix I (Risk Spreadsheets) of the Final Remedial
Investigatibn Report on the Potter's Septic Tank Service Pits Site
done by a previous consultant. Table 1-1, Carcinogenic Risk by
Location and Exposure Route, in the FS summarizes this information.
Calculation methodoligies are being presented for development of
cleanup goals.
COMMENT #12:
As a general policy, the Superfund Section of the State of North
Carolina currently considers any carcinogenic risk exceeding l.0E-
0 6 a significant risk to the population exposed. Therefore,
cleanup levels for carcinogens are based on a 1.0E-06 risk.
Enclosed is a copy of the Table 7 -2 3, "Carcinogenic Risk by
Location and Exposure Route." I have circled the risks from
exposure to carcinogens in Area lA and Area 1B that are considered
significant. Therefore, if the carcinogenic risk for the PAH group
or the non-PAH grounp exceed 1.0E-06 in any medium, cleanup levels
should be determined for those chemicals in that particular medium.
RESPONSE:
The modified Table 4-1 lists the soil cleanup levels for various
site-related carcinogens contaminants of concern (COCs). As
requested, the soil cleanup level is now calculated if the total
carcinogenic risk was greater than 1.0E-06 in any medium. Cleanup
levels are listed for 1.0E-06, 1.0E-05, l.0E-04 risk levels. The
attached calculation methodology will be included in an Appendix of
the revised FS report. The soil cleanup levels for protection of
groundwater is also listed in Table 4-1 calculated by W.N. O'Steen
of EPA Region IV and is outlined in his memo dated November 19,1991
to Darcy Duin, Remedial Project Manager.
COMMENT #13:
As a general policy, the Superfund Section of the State of North
Carolina currently considers any hazard index exceeding 1. 0 a
significant risk to the exposed population. Enclosed is a copy of
the Table 7-24 "Noncarcinogenic Risk by Location and Exposure
Route." I have circled the hazard indices for Area lA and Area 1B
that are significant. Therefore, cleanup levels should be
determined for each non-carcinogen within each critical effect
group if the hazard index exceeded one in a particular medium.
RESPONSE:
The modified Table 4-1 lists the soil cleanup levels for various
site related non-carcinogenic contaminants of concern. The soil
cleanup level was calculated if the total Hazard Index was greater
than 1.0 for COC in any medium. The cleanup levels are listed for
l.0E-06, 1.0E-05, l.0E-04 risks. The attached calulation
• •
methodology outlined in attachment #2 will be included in an
Appendix of the revised FS report.
All of these comments were discussed with the State and the
consultant was directed to respond in the above fashion.
SECOND DRAFT OF THE FEASIBILITY STUDY REPORT
A second Draft of the Feasibility Study report was sent to the
State with all of these comments addressed in the second draft on
April 8, 19 mments were asked to be received on this second
draft on , 1992. Comments were received from the State on
is second Draft on May 2-;,, 1992. Below is listed the responses
to all the comments outlined in this letter.
Comments on the Feasibility Study:
COMMENT #1:
Page 13, Section 1 -Indicates that area 1 will be evaluated in the
risk assessment as forest/wetland. If this area remains as
residential property (no deed restrictions) then the more
conservative assumption (forest/wetland vs. residential) should be
used. The forest/wetland scenario assumes there will be no
exposure to subsurface soils. If the area is also residential
property, subsurface soil exposure could occur through on-site
gardening or construction of basements/foundations.
RESPONSE:
In the Baseline Risk Assessment, the site was divided into three
areas. Area lA and Area lB was evaluated using the residential
scenarios. The Forest/Wetland region which includes the wetland
around Chinnis Branch was not evaluated using the residential
scenarios. EPA has determined that this area did not contain land
that is suitable for residential development.
COMMENT #2:
Page 19, Section 1 -States that a value of 723 ppm lead was used
in the risk assessment rather than the highest value detected at
the site (1300 ppm). Areas with soils exceeding cleanup goals will
require remediation.
RESPONSE:
As stated in the Feasibility Study in Table 4-1 listing the soil
contaminants of concern and the associated clean-up levels, lead is
a contaminant of concern with a risk based clean-up level of 11.2
ppm. In the ROD, the lead clean-up standard is 25 ppm which is
based on the protection of groundwater. As explained in Section
6.7 of the ROD, EPA guidance has recommended the use of 500 -1000
ppm clean-up standard for lead in soil. At Potter's, the standard
of 25 ppm for lead will be used which will be both protective of
• •
groundwater and human health. All areas with levels exceeding 25
ppm will be excavated and treated. There is no practical use in
recalculating this clean-up level.
COMMENT #3:
The groundwater model used to estimate time required for
remediation and to design an extraction system does not use the
highest concentrations of contaminants detected at the site. Since
modeling will only provide a "best guess' estimate, due to the use
of averaged data and many assumptions, it will likely be necessary
after groundwater extraction commences to alter pumping rates or
install additional wells to achieve cleanup goals within a
reasonable period of time.
RESPONSE:
This is recognized in the Feasibility Study and also contingency
measures are outlined in the ROD to take into account any changes
that may have to be made once the Remedial Action begins. The pump
and treat system will be continually monitored. During the process
wells can be added or deleted as needed and the treatment system
can be changed and adjusted as needed. ·
COMMENTS #4 -#17 were sent to the consultant to change the text.
Since there were not a considerable amount of changes, only the
pages requiring changes were edited. These changes to the FS are
included· in Attachment #3. Please revise the second draft with
these pages. The page numbers are located in the top right hand
corner. This second draft is the final Feasibility Study Report.
Comments on the Proposed Plan:
These comments were addressed in a letter sent to the State on July
27, 1992.
Comments from the North Carolina Division of Environmental
Management on the Draft Feasibility Study:
COMMENT #1 and #2:
1. The subject report correctly identifies the need to obtain an
air permit for equipment or activities that release reactive voes
to the atmosphere when emissions exceed forty pounds per day.
2. The need to obtain an air permit at the referenced site would
invoke the need to quantify emissions of toxic materials in
accordance with 15A NCAC 2H.0610 and 2D.1104. 15A NCAC 2H.0610
lists allowable emission rates for 105 elements or compounds. 15A
NCAC 2D.1104 lists acceptable ambient concentrations when an
allowable emission rate for a listed pollutant is exceeded.
• •
RESPONSE:
As stated in the ROD, since this is a CERCLA site and the treatment
will be occurring on site, no permits are required. Although, the
substantive requirements of any permits that are needed would be
met.
COMMENT #3:
The recommendation that thermal incineration not be retained for
further consideration as a treatment alternative, releives the Air
Quality Section of need to comment on incineration as an
alternative.
RESPONSE:
In the second draft of the FS, incineration was included in the
detailed analysis as a treatment alternative, but was not chosen in
the ROD as the selected remedy or the contingency remedy.
COMMENT #4:
Wetland protection is adequately addressed for this stage in the
project in part 3.3.7. This issue will need further attention as
the project moves forward. A NPDES permit for a discharge of
treated groundwater from this site is likely to require more than
120 days as identified in part 3.4.2 of the report. The time
schedule is variable due to many factors including: development of
effluent limitations, necessity to hold a public meeting or
hearing, and possible objections from the permittee. Part 5.2.10.1
indicates a surface water ischarge is an acceptable option for
disposal of the treated groundwater. it should be pointed out,
that prior to an application for a NPDES permit being considered
complete, a demonstration must be made that all non-discharge
alternatives have been considered and none found to be applicable.
A discharge NPDES permit is considered the least desirable
alternative.
RESPONSE:
Since the discharge of the treated effluent will
Branch on-site, a permit will not be required.
substantive requirements of a NPDES permit will
discharge Chinnis Branch.
RESPONSE TO COMMENT #1 ON THE DRAFT ROD:
COMMENT #1:
be in Chinnis
However, all
be met before
Additional comments on the Baseline Risk Assessment have been
provided by the North Carolina Environmental Epidemiology Section
(attached in original letter).
• •
RESPONSE:
Please refer to Attachment #4 which is a memo from the Risk
Assessment Section responding to all of the comments. W"-a.s Kc~\ t. PA; i slJ
I-"-'-' r c ~o,1 "'" f< < GENERAL COMMENT ON THE ROD: ~ <!. 0 s' "c. H,<:...I ~
Vu<> a;.~pfhi~ butt' 0
'
The ethylbenzene groundwater clean-up standard have been changed to ,I 5c ,v,J" '1
the North Carolina Standard which is the most stringent. The f c)uratk10/,
ethylbenzene clean-up· standard will be 29 ppb. Since this _.v..,l,
groundwater standard is being used, the time for remediation of the ~, ,c . aquifer and the cost of the clean-up has also changed. The time ta'
for remdiation will be approximately 50 years and the cost for the
groundwater remedy will be $7,100,000.
I hope this letter clarifies any misunderstanding that may have
happened between EPA and the State of North Carolina. If any of
these responses are not appropriate or need clarification, please
contact me as soon as possible. I would like to finalize the RI
Addendum and the Feasibility Study as soon as possible; therefore,
if the State has any more comments on these documents it would be
appropriate to send them at this time before the Administrative
Record is closed.
Thank you for your input on the RI Addendum, the Feasibility Study,
Proposed Plan, and the ROD. Please contact me at [phone] if
you have any questions or comments or would like to discuss these
responses further.
/4),:;ly ~
Darcy D~
Remedial Project Manager
cc: Curt Fehn, EPA
Attachments
• • Thia documem wu prepared by Roy F. Weston, tnc., expreaaty tor EPA. It shail not be released or disclasea, in whole or In part, without the expreu written permission of EPA.
•
TABLE 4-l
Remedial nves,igalion Addendum Report
Potter'• Septic Tank Pit Sita
Section: 4
Revision: 1
Date: April 1992
Page: 4 of 16
CURRENT NATIONAL PRIMARY DRINKING WATER STANDARDS
(Continued)
Contaminant MCL (mg/L)
lnor,mnics
Asbestos 7xl06 fibers/L
Arsenic 0.05
Barium LO
Cadmium 0.005
Chromium 0.1
Fluoride 4
Lead 0.05•
Mercury 0.002
Nitrate ( as N) 10
Nitrite ( as N) 1
Total Nitrate and Nitrite 10 (as nitrogen)
Selenium 0.05
Silver 0.05
Sodium and corrosion No MCL; monitoring and reporting only
On June 7, 1991, EPA fmalized the MCL for lead as a treatment technique with an action level of 0.015 mg/I.
B:\POTTERS\RISEC4.VLR
• • Thia document wu p,epared by Roy F. Wollan, Inc., exp,euiy tor EPA. It shall not be released or dlscloled. In whole or In part, without the expreaa written permiaaion of EPA.
Ramedial lnws1igalion /lddendwn Aepcrt
Potter·• Septic Tank Pit Site
Section: 4
Ravlalon: 1
Data: April 1992
Page: 9 of 16
are based on available concentration data, groundwater flow directions, identified source areas, and distribution of BTEX compounds in the shallow aquifer. The existing information is considered adequate to characterize the extent of VOC contamination in the deep aquifer.
4.2.2 Semj-Vo)atne Or~aoic Analyses
Numerous SVOCs were detected in samples collected from shallow groundwater monitoring wells at the site. Wells monitoring the deep aquifer revealed the presence of diethyl phthalate in two wells (at estimated concentrations of 7 ug/1 in well MW-102 and 1 ug/1 in well EPA-08). Review of Tables 4-1 and 4-2 indicate that MCLs and NCGWQSs are not available for the SVOCs detected at the site. SVOCs generally do not appear in shallow or deep wells which are considered as representative of background.
Based on the Phase II data, the extent of SVOC contamination in the shallow aquifer, as indicated from samples collected during the Phase II RI, is approximated by the 5 ug/1 total SVOC isopleth in Figure 3-22. Although some uncertainty exists in the extent of SVOC contamination northwest of well EPA-02, wells MW-211 and EP A-01 (north and west of well EPA-02, respectively) serve to limit this uncertainty. The extent of total SVOC contamination in the shallow aquifer appears to be adequately characterized.
Drinking Water Equivalency Levels (DWELs) have been developed for several SVOCs detected in groundwater at the site. For a scenario involving ingestion of the SVOC contaminated groundwater, non-carcinogenic effects were calculated based on the data collected during the initial RI. Using the Reference Dose presented in Appendix I (Risk Spreadsheets) of the RI. the DWELs were calculated. In the absence of established standards for these compounds, DWELs may be considered when establishing remedial goals. Table 4-3 summarizes this information for acenaphthene, dibenzofuran, 2,4-dimethylphenol, fluorene, 2-methylnapthalene, naphthalene, and phenanthrene. Comparing the DWELs from Table 4-3 to Phase II RI SVOC concentration data (Table 3-8), shallow wells EPA-02, EPA-03, EPA-OS, and MW-210 revealed one or more SVOCs at or above the computed DWELs. From Figure 3-22, the extent of SVOC cotamination in the shallow aquifer using DWELs for comparative purposes extends beyond the 250 ug/1 total SVOC isopleth, but does not extend as far the 5 ug/1 total SVOC isopleth.
B:\POTTERS\RISEC4.Vl.R
• • Thia document waa preparlld by Roy F. Waston, Inc., expreaaty for EPA It shaJI not be released or discloaed. in whole or in part. without the expreu written permiuion o1 EPA.
Remedial lnwotiga!lon l>ddendum Report
Potter', SepUc Tank Pit Site
Section: 4
Revision: 1
Date: April 1992
Page: 10 of 16
TABLE 4-3
DRINKING WATER EQUIVALENCY LEVELS
FOR SELECTED SEMI-VOLATILE ORGANIC COMPOUNDS
ea-., ' Gro,md,ntcrCoaa:uinticlll RdcrcnceDaoc1 DWFU
(mg/I) ( "'l/kg-day) (mi!/1)
Accnaphthcne 0.013 6.IJO X 102 2.10
Dibcnzofuran 0.00! N/A N/A
2,4-Dimcthytphcnol 0.12 6.IJO X l<f4 0.02
Fluorcnc 0.01 4.IJO X l(J2 1.40
2-Methylnapthalene 0.013 4.00x HJ3 0.14
Naphthalene 0.13 4.IJO X HJ3 0.14
Phcnanthrcnc 0.016 4.IJO X ICJ3 0.14
N/A • Not Available ~ Re(crcocc OOICI arc prcscatcd in Appendix I (Rist Sprcad.5b.ects) o( the Risk AsscssmcnL 2 Drinking Water Equivalcncy Levels. • Reference Dose x 70 kg (body weight of 1 adult) divided by 2 litcn/day (ingestion rate of an adull).
As previously discussed, the only SVOC detected in the deep aquifer is diethyl phthalate ( at 1 ug/1 in well EPA-08 and at 7 ug/1 in well MW-102). Existing risk assessment calculations do not include diethyl phthalate; however, the infrequency of detection of SVOCs in the deep aquifer indicate SVOC contamination has no significant impact on the deep aquifer. The existing SVOC information is considered adequate to characterize the extent of SVOCs in the deep aquifer.
4.2.3 Metals Analyses
Section 3.2.2.3 indicates the variability of metals present in the groundwater at the site. \Vhen compared to Tables 4-1 and 4-2, chromium and lead are the only heavy metals above the MCI.s (100 ug/1 for chromium, 15 ug/1 for lead or the NCGWQS (50 ug/1 for chromium, 50 ug/1 for lead). As previously discussed,
B:\POTTERS\RISEC4.Vl.R
• • Thia document wu prepared by Acy F. Waston. Inc., exprelmy for EPA. It shaJI not be released or disciosed, in whole or in part. without the •ll?f9U written permiaaion of EPA.
Romodial im.o■og..uo,, kldendum Aepcrt
Potter'■ Septic Tank Pit Site
Section: 4
Aevllion: 1
Date: April 1992
Page: 11 of 16
background concentrations for chromium in the shallow and deep aquifers appears to be below the NCGWQS and the current MCLs. Background concentrations of lead in the shallow and depp aquifer appears to be below the NCGWQS. However, lead concentratons in deep background wells MW-101 (40 ug/1) and MW-104 (32 ug/1) are above the lead MCL (as a treatment technology action level) of 15 ug/1. Consequently, background lead concentrations may constitute the ARAR for lead.
In the shallow aquifer, chromium concentrations in excess of 50 ug/1 during the Phase II RI sampling are approximated by the 50 ug/1 isopleth presented in Figure 3-26. As previously discussed, extent of contamination north of well MW-211 and south of well EPA-09, and well MW-203 is not well defined. As no trend of decreasing concentrations of chromium are observed in these areas, the extent of chromium contamination in these areas is considered to be undefined. Additional monitoring and possibly additional shallow wells are needed to adequately characteri2e the extent of chromium contamination in the shallow aquifer.
The extent of lead contamination in excess of 15 ug/1 in the shallow aquifer during the Phase II RI is approximated by the 10 ug/1 isopleth presented in Figure 3-28. As with chromium contamination in the shallow aquifer, the extent of lead contamination north of well MW-211 is uncertain. Extent of lead contamination south of well MW-203 and north of well TW-02 is uncertain. Additional monitoring and possibly additional shallow wells are needed to adequately characterize the extent of lead contamination in the shallow aquifer.
Due to the lack of sufficient data relative to background concentrations of chromium and lead in the deep aquifer, the extent of chromium and lead contamination in the deep aquifer is uncertain. Background concentrations in the deep aquifer appear to be less than 40 ug/1 for chromium and lead, based on concentrations of wells located in apparent background locations; therefore, the extent of chromium and lead concentrations north, south, and west of well MW-111 is uncertain. Similarly, at well MW-101, concentrations may represent background conditions; therefore, chromium or lead contamination may not be present in this area of the site. If the recent increase in chromium concentrations are not an anomalous event, then MW-101 appears to be monitoring deep aquifer groundwater impacted by chromium contamination. Additional monitoring and possibly additional deep wells are needed to adequately characterize the extent of chromium and lead contamination in the deep aquifer.
4.2.4 Other Analyses
Cyanide and PCBs were not detected in groundwater at the site. Only two pesticides were detected in groundwater. One of these, heptachlor epoxide at 0.026 ug/1 in well MW-210,
B:\POTTERS\RISEC4.VLR
• •
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part,
without the expresa written permission of EPA.
Remedial Investigation Addendum Report
Potter's Septic Tank Pit Site
Section: 4
Revision: 1
Date: April 1992
Page: 12 of 16
is below the NCGWQS of 0.038 ug/1. The other, 4,4'-DDD, at a concentration of 0.015 ug/1
in well EPA-01, does not have an MCL or NCGWQS established. The infrequency of
detection and the low concentrations observed in the two detected pesticides indicates that
pesticides are not contaminants of concern at the site. Where measured, total nitrogen is
below the MCL for total nitrate and nitrite (as nitrogen) of 10 mg/I.
4.3 SURFACE WATER AND SEDIMENT
Samples collected as a part of the Phase II RI revealed the presence of metals in the surface
water and sediments. Table 4-4 presents State of North Carolina Water Quality Standards
for Freshwater Classes. Comparison of metals concentrations for samples collected from
Chinnis Branch during the Phase II RI (Table 3-15) to the North Carolina standards
indicates that metals, other than copper, are below the State freshwater standards. Copper
in sample SW-1 was found at 850 ug/1 (Table 3-15) which exceeds the State's action level
of 7 ug/1 (Table 4-4) for freshwater aquatic life. It should be noted that sample SW-1 was
an upstream sample, and therefore, is not considered to be site related.
TABLE 4-4
WATER QUALl1Y STANDARDS FOR FRESHWATER CLASSES
Standards for All More Stringent
Standards to Support Freshwater Additional Uses1 Parameters
Aquatic Human WS Classes Trout Life Health
Arsenic (ug/L) 50
Barium (mg/L) 1.0
Benzene (ug/L) 71.4 1.19
Beryllium (ng/L) 6,500 117 6.8
Cadmium (ug/L) 2.0 0.4
Carbon tetrachloride (ug/L) 4.42 0.254
Chloride (mg/L) 230 (AL) 250
Chlorinated benzenes (ug/L) 488
Chlorine, total residual (ug/L) 17 (AL) 17
B:\POTTERS\RISEC4.VLR
• •
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, In whole or In part,
without the express written permission of EPA.
TABLE 4-4
Remedial Investigation Addendum Report
Potter's Septic Tank Pit Site
Section: 4
Revision: 1
Date: April 1992
Page: 13 of 16
WATER QUALllY STANDARDS FOR FRESHWATER CLASSES
(Continued)
Standards for All More Stringent
Standards to Support Freshwater Additional Uses 1 Parameters
Aquatic Human WS Classes Trout Life Health
Chlorophyll a, corrected (ug/L) 40 (N) 15 (N)
Chromium, total (ug/L) 50
Coliform, total (MFfCC/lOOmL) 50 (N)(2)
Coliform, fecal (MFfCC/lOOmL) 200 (N)
Copper ( ug/L) 7 (AL)
Cyanide ( ug/L) 5.0
Dioxin (ng/L) 0.000014 0.000013
Dissolved gases (N)
Dissolved oxygen (mg/L) 5.0 (Sw)(l) 6.0
Fluoride ( mg/L) 1.8
Hardness, total (mg/L) 100
Hexachlorobutadiene (ug/L) 49.7 0.445
Iron (mg/L) 1.0 (AL)
Lead (ug/L) 25 (N)
Manganese (ug/L) 50 (WSII &
III:200)
MBAS (ug/L) 500
(Methylene-Blue-Active Substances)
Mercury (ug/L) 0.012
Nickel (ug/L) 88 25
B:\POTTERS\RISEC4.VLR
• •
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part,
without the express written permission of EPA
TABLE 4-4
Remedial Investigation Addendum Report
Potter's Septic Tank Pit Site
Section: 4
Revision: 1
Date: April 1992
Page: 14 of 16
WATER QUALIIT STANDARDS FOR FRESHWATER CLASSES
(Continued)
Standards for All More Stringent
Freshwater Standards to Support
Parameters Additional Uses1
Aquatic Human WS Classes Trout Life Health
Nitrate nitrogen (mg/L) 10
Pesticides
Aldrin ( ng/L) 2.0 0.136 0.127
Chlordane ( ug/L) 4.0 0.588 0.575
DDT (ng/L) 1.0 0.591 0.588
Demeton (ng/L) 100
Dieldrin (ng/L) 2.0 0.144 0.135
Endosulfan (ng/L) 50
Endrin ( ng/L) 2.0
Guthion (ng/L) 10
Heptachlor (ng/L) 4.0 0.214 0.208
Lindane ( ng/L) 10
Methoxychlor (ng/L) 30
Mirex (ng/L) 1.0
Parathion (ng/L) 13
Toxaphene (ng/L) 0.2
2,4-D (ug/L) 100
2,4,5-TP (Silvex) (ug/L) 10
pH (units) 6.0-9.0 (Sw)
B:\POTTERS\RISEC4.VLR
• •
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, In whole or in part,
without the express written permission of EPA.
TABLE 4-4
Remedial Investigation Addendum Report
Potter's Septic Tank Pit Site
Section: 4
Revision: 1
Date: April 1992
Page: 15 ct 16
WATER QUALllY STANDARDS FOR FRESHWATER CLASSES
(Continued)
Standards for All More Stringent
Freshwater Standards to Support
Parameters Additional Uses1
Aquatic Human WS Classes Trout Life Health
Phenolic compounds (ug/L) (N) 1.0 (N)
Polychlorinated biphenyls ( ng/L) 1.0 0.079
Polynuclear aromatic 31.1 2.8
hydrocarbons ( ng/L)
Radioactive substances (N)
Selenium (ug/L) 5
Silver (ug/L) 0.06 (AL)
Solids, total dissolved (mg/L) 500
Solids, suspended (N)
Sulfates (mg/L) 250
Temperature (N)
Tetrachloroethane (1,1,2,2) (ug/L) 10.8 0.172
Tctrachloroethylene (ug/L) 0.8
Toluene (ug/L) 11 0.36
Toxic Substances (N)
Trialkyltin (ug/L) 0.008
Trichloroethylene (ug/L) 92.4 3.08
Turbidity (NTU) 50; 25 (N) 10 (N)
Vinyl chloride ( ug/L) 525 2
Zinc (ug/L) 50 (AL)
B:\POTTERS\RISEC4.VLR
• •
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part,
without the express written permission of EPA.
TABLE 4-4
Remedial Investigation Addendum Report
Potter's Septic Tank Pit Site
Section: 4
Revision: 1
Date: April 1992
Page: 16 of 16
WATER QUALl1Y STANDARDS FOR FRESHWATER CLASSES
(Continued)
Notes: 1 Chinnis Branch is classified as type C, Swamp. The additional use standards are presented for
comparative purposes only.
(N) See 15A NCAC. 2B .0211 (b), (c), (d), or (e) for narrative description of limits.
(AL) Values represent action levels as specified in 15A NCAC.0211 (b)(4).
(Sw) Designated swamp waters may have a pH as low as 4.3 and dissolved oxygen less than
5.0 mg/L if due to natural conditions.
(1) = An instantaneous reading may be as low as 4.0 ug/L, but the daily average must be
5.0 u,1/L or more.
(2) Applies only to unfiltered water supplies.
B:\POTTERS\RISEC4.VLR
• •
CLEANUP LEVEL CALCULATION METHODOLOGY
Carcinoiwnic
(Cltanup uvel for 10-Pj = (C-Onctntratim1)j • 10-P
(Summation Risk)i
Non-Carcino~enic
(Cleanup uvel) i = (Concentration) j
(Summation Ha:.ard Index Score) i
i = pathway
j = compound
P = 4, 5, 6, respectively
8:\P2\POTTERS\RPCSP002.CWS
25
20 -
~ -l ell 2,
= .:: -15 .. ... -= " " = C u
" 10
= " i:I "' =
5
0
5 7
Figure 2-3
Model Predictions
Restoration Time for Benzene
Note: Model predictions assume total source
removal; partial source removal will
result in increased restoration times.
-------------'-c----------~lOug/L
North Carolina MCL 1 u
9 11 13 15
Time (Years)
Federal MCL (5 ug/L)
17 19 21 23
•
•
25
~ -l ell :,
~ = .5: -"' .. -C ... " C 0 u ... C .. " C .. .=, -.:. = ..i
1000
900
800
700
600
500
400
300
200
1110
0
0
' ' ' ' ' ' ' ' ' ' ' ' ' ' I
I
I
I
I '
20
Figure 2-4
Model Predictions
Restoration Time for Ethylbenzene
Federal MCL (700 ug/L)
Obser\'ed Kd Value
Using Literature Koc Value
Note; Model predictions assume total source
removal; partial source removal will
result in increased restoration times.
------+-------------+-------------+------
40 60 80
Time (Years)
100 120 140
•
•
This document was prepared by Roy F. Weston, Inc., expresstyfor EPA. It shall not be released or disdosed, in whole or in part, without the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
I. Chem ical-S12ecific
ARARS
A. Resource Conservation 42 U .S.C. 6901 -
and Recovery Act 6987
I. Identification and 40 CFR Part 261
Listing of
Hazardous Waste
2. Releases from 40 C.F.R. Part 264
Solid Waste Subpart F
Management
Units
B:\P2\POTTERS\TB-SEC3.CWS
TABLE 3-2
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Defines those solid wastes which are Yes
subject to regulation as hazardous wastes
under 40 CFR Parts 262-270.
Establishes maximum contaminant Yes
concentrations that can be released from
solid waste units as part of RCRA
groundwater protection standards
(40 CFR 264.94).
F easbility Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: Apnl 1992
Page: 5 of 72
•
Justification
Comments
Potentially applicable to remedial
actions involving solid waste
removal in the identification of
wastes and application of other
action specific ARARs.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disciosed, In whole or in part, without the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
B. Clean Water Act 33 u.s.c. 1251-
1376
I. Water Quality 40 CFR Part 131
Criteria
2. Toxic Pollutants 40 CFR Part 129
C. Safe Drinking Water 40 u.s.c. 300
Act
I. National Primary 40 CFR Part 141
Drinking Water
Standards
8:\P2\POTTERS\ TB-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Sets non-enforceable guidance for water Yes
quality of surface waters based on toxicity
to aquatic organisms and human health.
Used by states to establish water quality
standards based on designated use.
Establishes effluent standards or No
prohibitions for certain "toxic pollutants" -
aldrin/dieldrin, DDT, endrin, toxaphene,
benzidiene, PCBs.
Establishes health-based enforceable Yes
standards for public water systems
(maximum contaminant levels (MCLs).
Feasbility Study
Potter's Septlc Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 6 otn
Justification
Comments
Potentially applicable to remedial
actions involving discharge of
•
treated groundwater to the Chinnis
Branch.
Current limited use and future
potential use of groundwater as a
potable water supply.
&
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disdosed,in whole or in part, wjthoutthe express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
2. National 40 CFR Part 143
Secondary
Drinking Water
Standards
3. Maximum 40 CFR Part 141
Contaminant
Level Goals
D. Clean Air Act 42 USC 7401
I. National Emission 40 CFR Part 61
Standards for
Hazardous Air
Pollutants
(NESHAP)
B:\P2\POTTERS\TB-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes aesthetic-based, non-Yes
enforceable guidelines for public water
systems (secondary maximum contaminant
levels) (SMCLs).
Establishes non-enforceable drinking Yes
water quality goals (MCLGs) set at levels
of no known or anticipated adverse health
effects with an adequate margin of safety
without consideration of available
treatment technology or cost.
Establishes emission standards for seven No
contaminants -benzene, mercury, arsenic,
asbestos, beryllium, vinyl chloride, and
radionuclides.
Feasbility Study
Potter's Septic Tank Pit Site
Sectlon: 3
Revision: 1
Date: Aprll 1992
Page: 7 of 72
Justification
Comments
Current limited use and future
potential use of groundwater as a
potable water supply.
Current limited use and future
potential use of groundwater as a
potable water supply.
•
Only benzene is a concern for the
site; however, the benzene
standard only applies to chemical
manufacturing, coke byproduct,
and petroleum refining activities
and not to hazardous waste sites.
This document was prepared by Roy F. Weston, Inc., expresstyfor EPA. It shall not be released or disclosed, in whole or in part, wrthout the express written pennission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
2. National Ambient 40 CFR Part 50
Air Quality
Standards
(NAAQS)
II. Loca tion-SQecific
ARARs
A. Resource 42 u.s.c. 6901-
Conservation and 6987
Recovery Act
I. Siting Criteria for 40 CFR 264.18
Hazardous Waste
Treatment,
Storage, and
Disposal Facili-
ties.
8:\P2\POTTEAS\TB-SEC3.CWS
TABLE 3-2
(Cootlnued)
ANALYSIS OF POTENTIAL FEDERAL ARA RS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes ambient air quality standards No
for seven classes of pollutants -carbon
monoxide, lead, nitrogen dioxide,
particulate matter, ozone, and sulfur
oxides. Standards do not apply directly to
source-specific emissions, but rather are
ambient concentration limitations.
Establishes siting requirements for new Yes
RCRA hazardous waste treatment, storage,
and disposal (TSD) facilities.
Feasbility Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: Aprll 1992
Page: 8 of 72
Justification
Comments
Only "major sources• (emissions
exceeding I00-250 tons per year
•
of regulated pollutants) are subject
to NAAQS attainment
requirements.
Potentially applicable if a TSD
facility is set up on-site to manage
removed RCRA hazardous waste.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part, without the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
B. Clean Water Act 33 U.S.C. 1251-
1376
I. Dredge or Fill 40 CFR Parts
Requirements 230-231
(Section 404)
C. Executive Order on Executive Order
Protection of No. 11,990
Wetlands 40 CFR 6.302(a)
and Appendix A.
D. Executive Order on Executive Order
Floodplain Manage-No. 11,988
ment 40 CFR 6,
Appendix A
E. Marine Protection 33 U.S.C.1401
Research and Sane-
tuaries Act
6:\P2\POTTEAS\ TB-SECJ.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARA RS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Requires permits for discharge of dredge No
or fill material into surface waters,
including filling of wetlands.
Requires consideration of the adverse Yes
impacts associated with the destruction or
loss of wetlands and to avoid support of
new construction in wetlands if a practical
alternative exists.
Requires evaluation of the potential No
effects of actions which may be taken in a
floodplain to avoid the adverse impacts
associated with direct and indirect
development of a floodplain.
Establishes requirement to protect No
designated marine sanctuaries.
Feasbility Study
Potter's Septic Tank Ptt Site
Section: 3
Revision: 1
Date: April 1992
Page: 9 of 72
Justification
Comments
Limited wetlands have been
tentatively identified at the site.
Also permit for discharge to
Chinnis Branch will require
delineation of wetlands.
The site is not located in a known
•
or suspected floodplain as defined
by FEMA.
The site is not located in or near
any known or suspected marine
sanctuaries.
This document was prepared by Roy F. Weston, Inc., expresstyfor EPA. It shall not be released or disclosed, in whole or in part, without the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
F. National Historic 49 u.s.c. 470
Preservation Act 40 CFR 6.301(b)
36 CFR Part 800
G. Archeological and 16 u.s.c. 469
Historical 40 CFR 6.301(c)
Preservation Act
H. Historical Sites, 16 u.s.c. 461-467
Buildings and 40 CFR 6.301(a)
Antiquities Act
I. Fish And Wildlife 16 u.s.c. 661-666
Coordination Act
J. Endangered Species Public Law 100-
Act 478 (October 7,
1988)
B:\P2\POTTERS\TB·SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Requires action to take into account No
effects on properties included in or
eligible for inclusion in the National
Register of Historic Places.
Establishes procedures to provide for No
preservation of historical and
archaeological data which might be
destroyed through alteration of terrain.
Requires consideration as to the existence No
and location of landmarks on the National
Registry of Natural Landmarks to avoid
undesirable impacts on such landmarks.
Requires adequate provision for protection No
of fish and wildlife resources when any
modification of any stream or other water
body is proposed.
Requires action to conserve endangered No
species and/or critical habitats upon which
endangered species depend.
Feasbility Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 1 O of 72
Justification
Comments
•
The site is not known or suspected
to contain properties included
and/or eligible for inclusion in the
National Register of Historic
Places.
The site is not known or suspected
to contain historical and/or
archaeological items.
The site is not known or suspected
to contain landmarks on the
National Registry of Natural
Landmarks.
Unnamed site stream does not
require modification.
The site is not known or suspected
to contain endangered species.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part, without the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
K. Coastal Zone 16 U.S.C. 1451
Management Act
L. Rivers and Harbors 33 u.s.c. 403
Act of 1899
I. Section IO Permit 33 CFR Parts
320-330
M. Wilderness Act 16 u.s.c. 1131
50 CFR 35.1
N. National Wildlife 16 u.s.c. 668
Refuge System Act
0. Wild and Scenic 16 u.s.c. 1271
River Act 40 CFR 6.30(e)
8:\P2\POTTERS\T8-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Requires non-interference with designated No
coastal zone management.
Requires permit for structures or work in No
or affecting navigable waters.
Administers federally-owned wilderness No
areas with intent to leave areas
unimpacted.
Restricts activities within a National No
Wildlife Refuge.
Prohibits adverse effects on a designated No
wild or scenic river.
Feasbility Study
Potter's Septic Tank Pi! Site
Section: 3
Revision: 1
Date: April 1992
Page: 11 of 72
Justification
Comments
The site is not located in or near a
coastal zone.
No navigable waters are present on
this site.
The site is not located in a known
or suspected federally-owned
wilderness area.
The site is not located in a known
or suspected national Wildlife
Refuge.
No known or suspected wild or
scenic rivers are located at the site.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part, withoutthe express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
III. Action-S12ecific
ARARS
A. Resource 42 u.s.c. 6901-
Conservation 6987
Recovery Act
I. Criteria for 40 CFR Part 257
Classification of
Solid Waste
Disposal Facilities
and Practices
2. Hazardous Waste 40 CFR Part 260
Management
Systems
3. Standards Applic-40 CFR Part 262
able to Generators
of Hazardous
Waste
B:\P2\POTTEAS\TB·SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Established criteria for use in determining No
which solid waste disposal facilities and
practices pose a reasonable probability of
adverse effects on public health or the
environment and thereby constitute
prohibited open dumps.
Establishes procedure and criteria for Yes
modification or revocation of provisions in
40 CFR Part 260-265.
Establishes standards for generators of Yes
hazardous wastes.
FeasbilityStudy
Potter's Septic Tank P~ Site
Section: 3
Revision: 1
Date: April 1992
Page: 12 of n
Justification
Comments
•
Not applicable as operations at the
site ceased prior to enactment of
RCRA.
Applicable as regulatory
provisions are analyzed without
modifications or revocation.
Potentially applicable to remedial
actions involving removal of waste
which qualify as hazardous under
RCRA.
This document was prepared by Roy F. Weston, Inc., expressly for EPA It shall not be released or disclosed, in whole or in part, without the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
4. Standards 40 CFR Part 263
Applicable to
Transporters of
Hazardous Waste
5. Standard for 40 CFR Part 264
Owners and
Operators of
Hazardous Waste
Treatment,
Storage, and Dis-
posai {TSD)
Facilities
a. General Subpart B
Facility
Standards
b. Preparedness Subpart C
and Prevention
B:\P2\POTTEAS\TB-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARA RS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes standards which apply to Yes
transporters of hazardous waste within the
United States if the transportation requires
a manifest under 40 CFR Part 262.
Establishes minimum national standards Yes
which define the acceptable management
of hazardous wastes for owners and
operators of facilities which treat, store, or
dispose of hazardous wastes.
Establishes administrative regulations for Yes
TSD operations.
Establishes design and operational Yes
requirements for TSD operations.
F easbility Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 13 of 72
Justification
Comments
Potentially applicable to remedial
actions involving removal of waste
which qualifies as hazardous under
RCRA.
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCR
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCRA.
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCRA.
This document was prepared by Roy F. Weston, Inc., expresstyfor EPA. It shall not be released or disclosed, in whole or in part, without the express written pem,isslon of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
C. Contingency Subpart D
Plan and
Emergency
Procedures
d. Manifest Subpart E
System,
Recordkeeping,
Reporting
e. Release from Subpart F
Solid Waste
Management
Units (SWMUs)
f. Closure and Subpart G
Post-Closure
g. Use and Subpart I
Management of
Containers
B:\PZ\POTTERS\TB-SECJ.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes regulations to minimize hazards Yes
to human health and the environment.
Establishes regulations on manifesting. Yes
Establishes regulations for monitoring and Yes
responding to releases from SWMUs.
Establishes regulations for owners and Yes
operators of hazardous waste management
facilities.
Establishes regulations for owners and Yes
operators of hazardous waste facilities that
store or treat waste in containers.
Feasbility Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 14 of 72
Justification
Comments
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCRA.
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCR
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCRA.
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCRA.
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCRA.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or dlsdosed, in whole or in part, -.· .. tthout the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
h. Tanks Subpart J
i. Surface Subpart K
lmpoundmen ts
j. Waste Piles Subpart L
k. Land Subpart M
Treatment
B:\P2\POTTEAS\TB-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARA RS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes regulations for owners and Yes
operators of hazardous waste facilities that
store or treat wastes in tanks.
Establishes regulations for owners and No
operators that use surface impoundments
to treat, store, or dispose of hazardous
waste.
Establishes regulations for owners and Yes
operators that treat or store hazardous
waste in piles.
Establishes regulations for owners and Yes
operators of hazardous waste land
treatment facilities.
Feasbility S1udy
Potter'sSepfic Tank Prt Site
Section: 3
Revision: 1
Date: April 1992
Page: 15 of 72
Justification
Comments
Potentially applicable to remedial
•
actions utilizing on-site TSO units
to manage removed wastes which
qualify as hazardous under RCRA.
Surface impoundments are not
present at the site nor proposed
for any remedial action.
Potentially applicable to remedial
actions utilizing on-site TSO units
to manage removed wastes which
qualify as hazardous under RCRA.
Potentially applicable to remedial
actions utilizing on-site TSO units
to manage removed wastes which
qualify as hazardous under RCRA.
Not applicable to wastes remaining
in-place as placement occurred
prior to enactment of RCRA.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed.in who!e or in part, without the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
I. Landfills Subpart N
m. Incinerators Subpart 0
n, Process Vents Subpart AA
o. Equipment Subpart BB
Leaks
B:\P2\~RS\TB-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes regulations for owners and Yes
operators of facilities that dispose of
hazardous waste in landfills.
Establishes regulations for owners and Yes
operators of facilities that incinerate
hazardous waste.
Establishes air emissions standards for Yes
process vents of selected RCRA TSD
treatment facilities.
Establishes air emission standards for Yes
equipment leaks from RCRA TSD
facilities.
F easbility Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Dale: April 1992
Page: 16 of n
Justification
Comments
Potentially applicable to remedial
•
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCRA.
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCR
Potentially applicable to remedial
actions utilizing on-site TSD units
to manage removed wastes which
qualify as hazardous under RCRA.
Potentially applicable to remedial
actions utilizing on-site TSD units
10 manage removed wastes which
qualify as hazardous under RCRA.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be r~eased or disclosed, in whole or in part, without the expiess written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
6, Interim Standards 40 CFR Part
for the Manage-265.400
ment of Specific Subpart Q
Hazardous Wastes
and Specific
Types of
Hazardous Waste
Management
Facilities
7. Standards for the 40 CFR Part 266
Management of
Specific
Hazardous Waste
and Specific
Types of
Hazardous Waste
Management
Facilities
B:\P2\POTTEAS\IB·SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARA RS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes minimum national standards Yes
that define the acceptable management of
hazardous waste during the period of
interim status and until certification of
final closure occurs, or, if the facility is
subject to post-closure requirements, until
post-closure responsibilities have been
fulfilled.
Establishes requirements which apply to Yes
recyclable hazardous waste materials that
are reclaimed.
Feasbility Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 17oln
Justification
Comments
Potentially applicable to on-site
remedial actions.
Potentially applicable to remedial
actions involving reclamation of
recyclable wastes which qualify as
hazardous under RCRA. May
apply to recovered non-aqueous
product.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disciosed,ir. whole er in part, without the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
8. Interim Standards 40 CFR Part 267
for Owners and
Generators of
New Hazardous
Waste Land
Disposal Facilities
9. Land Disposal 40 CFR Part 268
Restrictions
10. Hazardous Waste 40 CFR Part 2 70
Permit Program
11. Underground 40 CFR Part 280
Storage Tanks
(USTs)
B:\P2\POTTERS\T8-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes minimum standards that define No
acceptable management of hazardous
wastes for new land disposal facilities
during the period of interim status.
Establishes restrictions on land disposal of Yes
hazardous wastes.
Establishes provisions covering basic No
hazardous waste permitting requirements.
Establishes regulations related to USTs. No
Feasbllity Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 18 of 72
•
Justification
Comments
Interim status not applicable as
landfill operations ceased prior to
RCRA enactment (40 CFR 264
requirements are applicable).
Potentially applicable to remedial
actions involving removal of wast
which qualifies as hazardous under
RCRA.
Formal permits not required for
remedial action at CERCLA sites.
USTs are not present at the site
and will not be used as part of any
proposed remedial action.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part, withoui the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
B. Clean Water Act 33 u.s.c. 1251-
1376
I. National Pollutant 40 CFR Part 125
Discharge
Elimination
System (NPDES)
2. Effluent 40 CFR Part 40 I
Guidelines and
Standards for the
Point Source
Category
3. National Pretreat-40 CFR Part 403
ment Standard
8:\P2\POTTERS\TB-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Requires permit for effluent discharge Yes
from any point source into surface waters
of the United States.
Requires specific effluent characteristics Yes
for discharge under NPDES permits
Sets standards to control pollutants which Yes
pass through or interfere with treatment
processes in public treatment works which
may contaminate sewage sludge.
Feasbility Study
Potter's Septic Tank Pn sne
Seclton: 3
Revision: 1
Date: April 1992
Page: 19 of 72
Justification
Comments
Potentially applicable to remedial
actions involving discharge to
Chinnis Branch.
Specific contaminant limitations
may be established under a permi
if treated groundwater is
discharged to surface water body.
Potentially applicable to current
discharge of groundwater into
local POTWs.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disdosed, in whole or in part, without the express wrilien permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
C. Safe Drinking Water 40 u.s.c. 300
Act
I. Underground 40 CFR Parts
Injection Control 144-147
(UIC) Regulations
D. Clean Air Act 42 u.s.c 7401
I. New Source Per-40 CFR Part 60
formance
Standards (NSPS)
E. Occupational Safety 29 u.s.c. 651-678
and Health Act 29 CFR 1910
F. Hazardous Materials 49 U.S.C. 1801-
Transportation Act 1813
I. Hazardous 40 CFR Parts I 07,
Materials 171-177
Transportation
Regulations
B:\P2\POTTERS\TB-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Provides for protection of underground Yes
sources of drinking water.
Provides source-specific emissions Yes
standards for new sources of air emissions.
Regulates workers' health and safety Yes
Regulates transportation of DOT-defined Yes
hazardous materials.
Feasbility Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 20 of 72
Justification
Comments
Potentially applicable to remedial
actions involving re-injection of
groundwater or injection of
treatment chemicals.
Potentially applicable to remedial
actions involving incineration.
Applicable to remedial actions at
hazardous waste sites.
Applicable to remedial action
involving transportation of DOT-
defined hazardous materials off-
site.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disciosed,in whole or in part, without the express written permission of EPA.
Standard, Requirement, Regulatory
Criteria, or Limitation Citation
G. Surface Mining 30 u.s.c. 1201
Control and 30 CFR Part 816
Reclamation Act
H. Federal Insecticide, 7 u.s.c. 136
Fungicide, and 40 CFR Part 165
Rodenticide Act
I. Toxic Substances 40 CFR 761
Control Act
8:\P2\POTTERS\TB-SEC3.CWS
TABLE 3-2
(Continued)
ANALYSIS OF POTENTIAL FEDERAL ARA RS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes standards for surface coal No
mining operations.
Establishes management requirements for No
pesticide-containing wastes.
Establishes management requirements for No
PCB-containing wastes.
Feasbility Study
Potter's Septic Tank Pit Sile
Section: 3
Revision: 1
Date: April 1992
Page: 21 of 72
Justification
Comments
The site is not an active surface
coal mining operation.
•
Pesticides are not contaminants of
concern at the site.
PCBs are not present at the site. •
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed.in whole or in part, withoutthe express written permission of EPA.
Standard, Requirement,
Criteria, or Limitation Citation
I. Chemical-S12ecific
ARARS
A. NC Hazardous Waste 15A NCAC 13A
Management Rules
and Solid Waste
Management Law
I. Identification and 15 A NCAC
Listing of Hazar-13A.0006
dous Waste
B. Water Quality 15 A NCAC
Standards Applicable 2B.0100
to the Surface Waters
of NC
C. NC Drinking Water General Statutes
Act Chapter 130A,
Article I 0
B:\P2\POTTERS\TI3-SEC3.CWS
TABLE 3-3
ANALYSIS OF POTENTIAL STATE ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Defines those solid wastes which are Yes
subject to state regulation as a hazardous
waste. Consistent with corresponding
federal standards (characteristic and listed
hazardous waste designations).
Establishes acceptable water quality-Yes
related parameters in state surface water.
Establishes criteria for protection of state Yes
public water supplies.
Feasbility Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 22 of 72
Justification
Comments
Potentially applicable to remedial.
actions involving solid waste
removal.
Potentially applicable to remedial
actions involving discharge of
treated groundwater into Chinnis
Branch.
Current limited use and potential
future use of groundwater as a
potable water supply.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part, without the express written permission of EPA.
Standard, Requirement,
Criteria, or Limitation Citation
D. NC Water and Air General Statutes,
Resources Act Chapter 143
Article 2 I
I. Emission NCAC Title 15 A
Standards for Chapter 2
Hazardous Air Subchapter 2D
Pollutants
2. NC Ambient Air NCAC Title 15 A,
Quality Standards Chapter 2,
(NCAAQS) Subchapter
2D.0400
E. NC Groundwater NCAC Title 15A,
Quality Standard Chapter 2,
Su bchapters
2L.0I00, 2L.0200,
2L.0300
B:\P2\POTTERS\TB-SEC3.CWS
TABLE 3-3
(Continued)
ANALYSIS OF POTENTIAL STATE ARARS
Description
Adopts by reference federal emissions
standards (NESHAP) for seven
contaminants -benzene, mercury, arsenic,
asbestos, beryllium, vinyl chloride, and
radionuclides.
Adopts federal ambient air quality
standards (NAAQS) for seven classes of
pollutants -Carbon monoxide, lead,
nitrogen dioxide, particulate matter,
ozone, and sulfur oxides.
Establishes a series of classifications and
water quality standards applicable to
groundwater of the State.
Applicable
and/or
Relevant and
Appropriate
(Yes/No)
No
No
Yes
Feasbility Study
Potter's SepUc Tank Pit Site
SecUon: 3
Revision: 1
Date: April 1992
Page: 23 of 72
•
Justification
Comments
Only benzene is a concern for the
site; however, the benzene
standard only applies to chemical
manufacture coke byproduct and
petroleum refining activities, not •
to hazardous waste sites.
Only "major sources" (emissions
exceeding 100-250 tons per year
of regulated pollutants) are subject
to NCAAQS attainment
requirements.
Potentially applicable to remedial
actions involving remediation of
groundwater.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part, without the express written permission of EPA.
Standard, Requirement,
Criteria, or Limitation Citation
II. Location-S11ecific
ARARs
A. NC Solid and General Statutes,
Hazardous Waste Chapter 130A,
Management Act Article 9
I. Siting Criteria for 15 A NCAC
Hazardous Waste 13A.0009
Treatment and
Disposal Facilities
B. Conservation of 15A NCAC
Marine, Estuarine, 10.0100
and Wildlife 10.0200
Resources
III. Action-S11ecific ARARs
A. NC Solid and General Statutes,
Hazardous Waste Chapter 130A,
Management Act Article 9
8:\P2\POTTEAS\IB-SECJ.CWS
TABLE 3-3
(Continued)
ANALYSIS OF POTENTIAL STATE ARA RS
Description
Establishes state siting criteria for new
hazardous waste treatment and disposal
facilities.
Allows the State Game Commission to
protect, propagate, manage, and preserve
game fur-bearing animals and birds
through management of lands for public
hunting.
Applicable
and/or
Relevant and
Appropriate
(Yes/No)
Yes
No
F easbility Study
Potter's Sepllc Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 24 of 72
Justification
Comments
Potentially applicable if a
treatment and/or disposal facility
is set up on-site to manage
removed hazardous waste.
The site is private property and is
not a public land designated for
hunting activities.
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part, without the express written permission of EPA.
Standard, Requirement,
Criteria, or Limitation Citation
I. Solid Waste 15 A NCAC 13B
Management
Rules
2. Hazardous Waste 15 A NCAC 13A
Management
B. Water Pollution NCAC Title 15
Control Regulations Chapter 2,
Subchapter 2H
2. Wastewater NCAC Title 15,
Treatment Chapter 2,
Requirements Subchapter 2H.0 I
3. Erosion Control 15A NCAC
Chapter 4
Subchapter 4B
B:\P2\POTTEAS\TB-SEC3.CWS
TABLE 3-3
(Continued)
ANALYSIS OF POTENTIAL STATE ARARS
Description
Establishes state-level comprehensive
residual waste management system.
Establishes state-level version of
comprehensive hazardous waste
management system.
Requires permit for discharge of effluent
from point sources into surface waters.
State-level version of federal NPDES
program.
Establishes basic wastewater treatment
requirements for effluent discharge.
Establishes erosion and sedimentation
control measures for earth-moving
activities.
Applicable
and/or
Relevant and
Appropriate
(Yes/No)
Yes
Yes
Yes
Yes
Yes
Feasbilily Study
Potter's Septic Tank Pit Site
Section: 3
Revision: 1
Date: April 1992
Page: 25 ol 72
Justification
Comments
Potentially applicable to remedial
actions involving removal of
wastes that qualify as residual
waste.
Potentially applicable to remedial
actions involving removal of
wastes that qualify as hazardous
wastes.
Potentially applicable to remedial
actions involving point source
discharges to surface waters.
Potentially applicable to remedial
actions involving point source
discharges.
Potentially applicable to remedial
actions involving earth moving.
•
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or discJosed, In whole or in part, without the express written pennission of EPA.
Standard, Requirement,
Criteria, or Limitation Citation
C. NC Water and Air General Statutes
Resources Act Chapter 143,
Article 21
I. Standards for NCAC Title 15A,
Contaminants Chapter 2,
Subchapter 2D
2. Standards for NCAC Title 15A,
Sources of voes Chapter 2,
Subchapter 2D
D. NC Groundwater NCAC Title 15A,
Quality Standards Chapter 2,
Subchapters
2L.0IO0, 2L.0200,
2L.0300
E. NC Well General Statues
Construction Act Chapter 87
8:\P2\POTTEAS\TB-SEC3.CWS
TABLE 3-3
(Continued)
ANALYSIS OF POTENTIAL STATE ARARS
Applicable
and/or
Relevant and
Appropriate
Description (Yes/No)
Establishes state source-specific emissions Yes
limitations for particulate matter, sulfur
compounds, odor, and opacity.
Establishes state standards for storage Yes
tanks containing voes.
Establishes a series of classifications and Yes
water quality standards applicable to
groundwater of the State.
Establishes requirements about the Yes
location, construction, repair, and
abandonment of wells, of pumps and
pumping equipment.
Feasbility Study
Potter's Septic Tank Ptt Site
Section: 3
Revision: 1
Date: April 1992
Page: 26 of n
•
Justification
Comments
Potentially applicable to remedial
actions involving air emissions,
principally incineration.
Potentially applicable to remedial
actions utilizing storage tanks for
voe-containing wastes.
Potentially applicable to remedial
actions involving remediation of
groundwater.
Potentially applicable to remedial
actions involving construction of
wells.
• •
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part,
without the express written permission of EPA.
Feaslbility Study
Potter's Septic Tank Pits Sita
Section: 3
Revision: 1
Date: April 1992
Page: 27 of 70
These ''To Be Considered" (TBC) issues are not potential ARARs but are evaluated as
appropriate along with ARARs. Section 3.6 addresses TBC issues identified for the site.
3.3 FEDERAL ARARs
Federal ARAR sources found to be potentially applicable to the site are discussed below
and consist of:
• Resource Conservation and Recovery Act (RCRA)
• Clean Water Act (CWA)
• Safe Drinking Water Act (SOWA)
• Oean Air Act (CAA)
• Occupational Safety and Health Act (OSHA)
• Hazardous Materials Transportation Act
• Wetlands Protection (Executive Order 11990)
3.3.1 Resource Conservation and Recovecy Act
The Resource Conservation and Recovery Act (RCRA) (42 USCA 6901 et seq.) mandated
EPA to:
• Establish a comprehensive regulatory program to control and manage
hazardous waste, under Subtitle C.
• Promulgate regulations containing guidelines to assist in the development and
implementation of state nonhazardous solid waste management plans, under
Subtitle D.
• Establish a comprehensive regulatory program to address underground
storage tanks (USTs), under Subtitle I.
Discussion of the North Carolina Solid Waste Management Law and associated hazardous
and nonhazardous solid waste regulatory requirements is presented in Subsection 3.4.5. The
remainder of this subsection provides discussion of hazardous waste-related regulatory
requirements promulgated under Subtitle C of RCRA. In addition, Subtitle I regulatory
requirements for USTs are also addressed under the discussion presented for tank systems.
RCRA requirements with regard to hazardous waste management may be applicable as
some of the waste material at the site may potentially qualify as a RCRA characteristic
hazardous waste under EPA's recently enacted Toxicity Characteristic (TC) regulations
B:\P2\POTTEAS\FS·SECJ.CWS
• •
Thia document was prepared by Roy F. Waston, Inc., expressly for EPA. It shail not be released or disclosed, In whole or In part,
without the express written permission of EPA
TABLE 3-4
Feaalblllty Study
Potter's Septic Tank Pita Sito
Section: 3
Revision: 1
Date: April 1992
Pago: 46 of 70
CURRENT NATIONAL PRIMARY DRINKING WATER STANDARDS
Organics
Benzene
Contaminant
Carbon tetrachloride
para-Dichlorobenzene
1,2-Dichloroethane
1,1-Dichloroethylene
1,1,1-Trichloroethane
Trichloroethylene
Vinyl chloride
Trihalomethanes
(sum of chloroform, bromoform, bromodi-
chloromethane, dibromochloromethane)
Dichlorobenrene o•, m•,
cis-1,2-Dichloroethylene
trans-1-2-Dichloroethylene
1,2-Dichloropropane
Ethylbenzene
Monochlorobenzene
Styrene
Tetrachloroethylene
Toluene
Xylene (total)
Benz(a)anthracene (PAH)
Benz( a)pyrene (P AH)
Benzofluoranthene (P AH)
Benzo(k)fluoranthene (PAH)
Chrysene (P AH)
Indenopyrene (P AH
Dibenz(a,h)anthracene (PAH)
Other Organics (Pesticides and PCBs)
2,4-D
Endrin
Lindane
Methoxychlor
Toxaphene
2,4,5-TP (Silvex)
Alachlor
Atrazine
B:\P2\POTTERS\FS-SECJ.CWS
MCL (mg/L)
0.005
0.005
0.075
0.005
0.007
0.20
0.005
0.002
0,10
0.6
0.07
0,1
0.005
0.7
0.1
0.1
0.005
1.0
10,0
0.0001 (1)
0.0002 (1)
0.0002 (1)
0,0002 (1)
0.0002 (1)
0.0004 (1)
0.0003 (1)
0.07
0.002 (P)
0.0002
0.04
0.003
0.05
0.002
0.003
•
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part,
without the expresa written permission of EPA.
TABLE3-4
(Continued)
Feaalbllity Study
Potter's Septic Tank Pits sue
Section: 3
Revision: 1
Data: April 1992
Pago: 47 of 70
CURRENT NATIONAL PRIMARY DRINKING WATER STANDARDS
Contaminant
Other Organics (Pesticides and PCBs) (Continued)
Carbofuran
Chlordane
Dibromochloropropane
Ethylene dibromide
Heptachlor
Heptachlor epoxide
Polychlorinated biphenyls (PCBs)
Inorganics
Asbestos
Arsenic
Barium
Cadmium
Chromium (total)
Fluoride
Lead
Mercury
Nitrate (as N)
Nitrite ( as N)
Total nitrate & nitrite
Selenium
Sodium and corrosion
1 -Proposed MCL
B:\P2\POTTEAS\FS.SEC3.CWS
MCL (mg/L)
0,04
0.002
0.0002
0.00005
0.0004
0.0002
0.0005
7x106 fibers/L (longer than 10 microns)
0.05
2.0
0.005
0.1
4
0.015 ( action level)
0.002
10
1
10 ( as nitrogen)
0.05
No MCL; monitoring and
reporting only
• •
Thia document was prepared by Roy F. Weston, lnc., expreasly for EPA It shall not be released or dlscJosed, In whole or In part,
without the expresa written permission of EPA.
•
•
•
•
Feasibility Study
Potter's Septic Tank Pits Site
Section: 3
Revision: 1
Data: April 1992
Page: 56 of 70
Required manifest information (49 CFR 172.101, 172.203, and 173) including
proper shipping name, hazard classification, and identification number.
Transportation mode requirements (49 CFR 172.101 and 174-177) .
Packaging. labeling. and marking requirements ( 49 CFR 172, 178, and 179) .
Traru;portation placarding requirements ( 49 CFR 172, Subpart F) .
3.3.7 Wetlands Protection
Through Executive Order No. 11990, regulations regarding protection of wetlands were
promulgated by EPA under 40 CFR 6.032. Limited wetland areas have been tentatively
identified at the site. The following action-specific regulatory requirements represent
potential ARARs:
3.4
• Avoid adverse impacts associated with the destruction or loss of wetlands.
• Avoid new construction on wetlands unless no other practical alternative
exists.
• Prepare a wetlands assessment if wetlands will be affected.
• Minimize adverse impact on wetlands if no practicable alternative to the
action exists.
STATEARARs
State ARAR sources found to be potentially applicable to the site are discussed below and
consist of the following:
• North Carolina Solid and Hazardous Waste Management Act (state level
equivalent to Federal RCRA)
• North Carolina Water and Air Resources Act (state level equivalent to
Federal CWA and CAA)
• North Carolina Drinking Water Act (state level equivalent to Federal SDWA)
• Guidelines for Remediation of Soil Contaminated by Petroleum
B:\P2\POTTERS\FS-SEC3.CWS
This document was prepared by Roy F. Weston, Inc., expressty for EPA. It shall not be released or disclosed, in whole or in part,
without the express written pennission of EPA.
TABLE 4-1
Feasibility Study
Potter's Septic Tank Pits Site
Section: 4
Revision: 1
Date: April 1992
Page: 3 of 14
Potential Cleanup Levels For Soils
Potential Cleanup Levels
Mean Cone. Carcinogenic Non-Carcinogenic
Chemical mg/kg Risk Risk Hazard Index
(HI)1
Surface Soil {Area I Al
Benzene 0.73 1.96 X 10·5
Carcinogenic PAH2 5.13 4.65 X 10-4
Lead 722.51 64.5
Surface Soil {Area I Bl
Benzene 0.096 2.61 X 10-6
Lead 250 22.38
Zinc 2269.19 18.61
Surface Soil {Wetlands}
Carcinogenic PAH 0.44 3.18 X 10-6
Subsurface3 Soil {Area IA}
Carcinogenic PAH 14.7 I 2.07 X 10-6
I: Non-carcinogenic metal cleanup level based on attainment of a Hazard Index of I.
2: Carcinogenic Polynuclear Aromatic Hydrocarbons.
3: Depths below 3 feet have been considered subsurface as in the Risk Assessment.
8:\P2\POTTEAS\FS-SEC4.CWS
(mg/kg)
E-06 E-05 E-04
0.037 0.37 3.7
0.01 I 0.11 I.I
0.037 0.37 3.7
0.138 1.38 13.8
7.106 71.06 710.6
Hl=l
11.2
11.2
122 •
• • This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, In whole or in part,
without the express written permission of EPA.
Feasibility Study
Potter's Septic Tank Pits Site
Section: 4
Revision: 1
Date: April 1992
Page: 9 of 14
Figure 4-5 shows those soil locations and areas found to exceed the cleanup levels based on
1 x 10"' human health risk levels. Figure 4-5 also shows the extent of surface soil
remediation for the depth interval of 0.0 ft to 3.0 ft.
Figures 4-6, 4-7, and 4-8, show those soil locations and areas found to exceed the cleanup
levels necessary for the protection of groundwater. Figure 4-6 shows the extent of surface
soil remediation for the depth interval of 0.0 ft to 3.0 ft. Figures 4-7 and 4-8 show the
extent of subsurface soil remediation for the depth intervals of 3.0 ft to 6.0 ft and 6.0 ft to
10.0 ft, respectively.
4.2.2 Groundwater
4.2.2.1 Volatile Organic Compounds
For volatile organic compounds (VOCs) in groundwater at the site, Federal (maximum
contaminant levels, MCLs) and State of North Carolina Groundwater Quality Standards
(NCGWQS) provide the applicable cleanup standards. Of the VOC concentrations
observed, the BTEX compounds constitute the principal contaminants of concern, with
benzene having the most restrictive standard (a NCGWQS of 1 mg/I). While the other
BTEX compounds are present above their respective MCI...s and NCGWQSs, these
compounds are generally no more laterally or vertically extensive than benzene, and have
less restrictive MCI...s and NCGWQSs than benzene. Treatment technologies selected for
remediation of benzene contamination at the site will also be effective in treating the other voes.
4.2.2.2 Semi-Volatile Organics
No MCLs or NCGWQS exist for those semi-volatile organic compounds (SVOCs) detected
in groundwaters at the site. Therefore, risk-based calculations were performed to provide
Drinking Water Equivalency Levels (DWEI...s) for those SVOCs detected during the RI and
RI Addendum for which risk data were present in Appendix I (Risk Spreadsheets) of the
RI. Concentrations of two of the SVOCs, 2,4-Dimethylphenol and Naphthalene, were
observed above DWEI...s in shallow wells EPA-02, EPA-03, EPA-05, and MW0210, and in
shallow wells EPA-02, EPA-05, and MW-210, respectively. These wells also exhibited the
largest sums for total SVOCs. Treatment technologies have been selected for total SVOCs,
which will deal effectively with the specified SVOCs found above DWELs in groundwater
at the site.
B:\P2\,POTTERS\FS·SEC4.CWS
• • Thia document waa prepared by Acy F. Weston, Inc., expressly for EPA It shatl not be released or disclosed, in whole or in part,
without the express written permission of EPA.
4.2.2.3 Metals
Feasibility Study
Potter's Septic Tank Pits Site
Section: 4
Revision: 1
Date: April 1992
Page: 14 of 14
For metals detected in groundwaters at the site, chromium and lead are present at
concentrations above Federal MCLs (100 ug/1 for chromium, 15 ug/1 for lead), or the
NCGWQS (50 ug/1 for chromium, 50 ug/1 for lead).
The full extent of metals contamination in groundwater, however, has not been clearly
defined. Analytical data as presented in the RI and RI Addendum indicate the presence
of chromium and lead in wells. Based on the well location and the existing groundwater
flow direction, however, the metal levels should be considered background or potentially the
result of high soil fines levels in the unfiltered groundwater sample. Specifically, the extent
of lead and chromium contamination in the shallow aquifer north of MW-211 and south of
MW-203 and TW-02 is uncertain. Similarly, background levels for lead and chromium in
the deep well aquifer are undefined at points north, south, and west of MW-111. Additional
monitoring, additional shallow wells, and additional deep aquifer wells and/or resampling
to obtain low solids groundwater samples (i.e. either filtered or obtained under pumping
conditions to reflect low turbidity obtainable in water supply wells) are needed to adequately
characterize the extent of metals contamination in groundwater for the site.
For areas of contamination within the zone of influence for potential groundwater treatment
alternatives, the cleanup goal will be established at background levels or at 50 ug/1 for total
chromium and 50 ug/1 for lead in accordance with the NCGWQS. For purposes of
discussion and design, NCGWQS standards will be referenced as the basis for cleanup goals
for metals in groundwater in this report. As additional analytical data may clarify
background levels and the extent of contamination within the aforementioned areas, the
treatment system for groundwater may be modified.
8:\P2\POTTERS\FS·SEC4.CWS
Figure 5-2
Summary of Technologies and Process Options for Soils
General Remedial Process Description Screening
Response Action Technology Options Recommendation
No Action None Not Appllcable No action. Retained as required for
consideration by NCP.
Restrict Deed Annot.ating the property Retained.
deed.
lnstttutlonal Restrict Access
Fencing Construct n fence. Retained.
Excavation Excavate Not Appllcable Contaminated soil removal. Retained.
Cement Portland cement mixed
with soil waste.
Retained.
~~ Physical entrapment with Not Retained. :xx.x..x.x.;x __ siliceous material.
Stablllzatlon Thermoplastlc Asphalt used to bind waste Retained.
material.
Urea formaldehyde polymer Not retained.
stabilizes the waste.
Elutriation of contaminant.~ Retained.
from soil with solution.
Physlcal/Chemlcal In place method of soil Not retained.
washing,
Strip volatiles with air. Not retained.
Treatment
Removal of chlorine atoms. Not retained.
Add nutrients to promote Not retained.
Blolog1cal bacterial growth.
Create a soil/water slurry Not relfiined.
in a reactor.
Subject to high temperature Retained.
to destroy organics.
Thermal
Soil converted to inert glass. Not retained.
Construction of RCRA-Not retained.
level landfill.
Dlsposal Landfill
Off-site Landfill Excavation & transport to a Retained.
RCRA landfill.
Slngle-Layer Asphalt/concrete/soil cover. Retained.
Capping Multl-l.ayer Clay with vegetative cap. Retained.
FML Uner Synthetic and soil liners. Retained.
Containment
Basin/Pond Channel runoff to basins. Retained.
Surface Control
Diversion Surface grading and Retained.
10@ revegetation.
Technologies that
are screened out
90&7784A
• •
This document was prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, In whole or in part,
without the express written permission of EPA.
Technology/ Approach Status
6-Foot Cyclone Fence with Not selected Barbed Wire Top
Feasibility Study
Potter's Septic Tank Pits Site
Section: 5
Revision: 1
Date: April 1992
Page: 4 of 51
Reason
Not cost-effective; over-protective; risk of injury.
Effectiveness -The selected alternative ( 6-foot cyclone fence) would effectively restrict
access to contaminated areas and provide a measure of human health protection by
providing an "early warning" if, and when, drinking water supplies are threatened.
Implementability -The fencing portion of this option can be readily implemented; however,
legal actions concerning the permanent relocation of the resident must be resolved.
~ -Capital costs for fencing are minimal but relocation and purchasing of land to
relocate the mobile homes would be moderate. Operating and maintenance costs of this
option are minimal.
Recommendation -This option will be retained for further consideration.
5.1.3 Soil Excavation
Description -Excavation involves the physical removal of contaminated soil and sediments.
The extent of excavation depends on the site characteristics and remedial goals. For the
Potter's Pits site, selected "hot spot" excavations would likely be effective. The excavated
soils may be treated to remove or immobilize contaminants or may be left untreated for off-
site disposal. The excavated area may be filled, as necessary, with the original materials
after appropriate treatment or with clean fill material.
Effectiveness -This technology is very effective since the source of contamination would be
removed to acceptable action levels. Removal of the contaminant source will benefit the
groundwater cleanup activities and eliminate further migration of contaminants into the
groundwater.
Implementabiljty -Excavation is a conventional technology which is accomplished with
commonly used equipment and techniques. General surface runoff control could be
required under general construction standards.
~ -The cost of this technology is moderate.
Recommendation -This technology will be retained for further consideration in combination
with soil disposal/treatment techniques.
B:\P2\POTTERS\FS·SEC5.CWS
• •
This document waa prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, In whole or In part,
without the express written permission of EPA.
Feasibility Study
Potter's Septic Tank Pits Site
Sectlon: 5
Revision: 1
Date: April 1992
Page: 13 of 51
Implementability -Bench or pilot-scale tests would be required to determine the feasibility
of bioreclamation for organics under site conditions and to determine design and operating
parameters. As with soil flushing, controlling flow through the subsurface zone is essential.
Recovery wells must be placed to ensure complete capture of the enriched/treated
groundwater and to prevent transport of potentially toxic degradation products beyond the
treatment zone.
In a manner similar to soil flushing technologies, in-situ biological techniques may result in
an increased contaminant mobility and a subsequent increase in the rate of contaminant
migration.
~ -Cost of this technology is expected to be moderate.
Recommendation -The low levels for carcinogenic P AH will be difficult to achieve with this
technology. Also, metals will have to be flushed out and treated ex-situ. Hence, in-situ
bioreclamation will not be retained for further consideration.
5.1.4.3.2 Biosluny
Description -Biological treatment is a technique for treating contaminated soils in a reactor.
This is accomplished by the addition of oxygen and nutrients to soil to enhance the natural
biodegradation of organic compounds by microorganisms, resulting in the breakdown and
detoxification of the organic contaminants. These microorganisms can be naturally
occurring, specially adapted, or genetically engineered.
Nutrients and, if necessary, oxygen are delivered to the soils through injection wells or an
infiltration system. Water sometimes accompanied by surfactants is often used to carry the
nutrients.
Effectiveness -Review of the literature indicates that bioslurry has been successfully used
in tests on materials contaminated with polynuclear aromatic hydrocarbons and acid
extractable compounds. The process is sensitive to a number of environmental factors,
including availability of trace nutrients, oxygen concentration, redox potential, pH degree
of water sturation, and temperature. These factors would have to be monitored and
controlled during operation.
Implementability -Bench or pilot-scale tests would be required to determine the feasibility
of the process and to determine design and operating parameters.
Cost -Cost of this technology is expected to be moderate.
B:\P2\POTTEAS\FS.SECS.CWS
• •
CLEANUP LEVEL CALCULATION METHODOLOGY
Carcinogenic
(Cleanup Level for 10-Pj =
Non-Carcinogenic
(Concentration)j * 10-P
(Summation Risk)i
(Cleanup Level) j = ___ _,_(C.:..o.:..n.;.:c..:..en..:..tr.:...a_tz_·o_n-'-) .,_j __ _
(Summation Hazard Index Score) i
i = pathway
j = compound
P = 4, 5, 6, respectively
B:\P2\POTTEAS\RPCBP002.CWS
CLEANUP LEVELS FOR SURFACE AND SUBSURFACE SOILS
SO:ZPOTSOIL
Carcinogenic INCREMENTAL RISK
Parameter SOIL DIRECT ROOT ALL PLANT TOTAL SOIL
INGESTION CONTACT LEAFY OTHER UPTAKE RISK CONC. CLEAN UP LEVEL (mg/kg)
PLANTS PLANTS (mg/kg) 1 E-06 1 E-05 1E-04 • AREA1A
Benzene 8.60E-09 3.90E-10 1.33E-06 1.83E-05 1.96E-05 1.96E-05 0.730 0.037 0.372 3.717
PAHs 1.20E-05 1.10E-04 2.36E-05 3.19E-04 3.43E-04 4.65E-04 5.130 0.011 0.110 1.104
AREA 1B
Benzene 1.10E-09 5.1 0E-11 1.60E-07 2.45E-06 2.61 E-06 2.61 E-06 0.096 0.037 0.368 3.677
WETLAND/FORESTS
PAHs 5.80E-07 2.60E-06 3.18E-06 0.44 0.138 1.384 13.836
Non-carcinogenic RISK RATIO
Parameter SOIL DIRECT ROOT ALL PLANT TOTAL SOIL
INGESTION CONTACT LEAFY OTHER UPTAKE RISK CONC. CLEAN UP LEVEL (mg/kg)
PLANTS PLANTS (mg/kg) 1E-06 1E-05 1E-04 • AREA1A
Lead 5.3 2.40E-01 1.60E+01 4.30E+01 5.90E+01 6.45E+01 722.51 1 .12E+01 1.12E+01 1.12E+01
Zinc 8.80E-04 3.90E-05 8.90E-02 7.20E-03 9.62E-02 9.71 E-02 172.2 1.77E+03 1.77E+03 1.77E+03
AREA 1B
Lead 1.80E+00 8.20E-02 5.50E+00 1.50E+01 2.05E+01 22.382 250 1.12E+01 1.12E+01 1.12E+01
Zinc 1.20E-02 5.20E-04 9.30E+00 9.30E+00 1.86E+01 18.61252 2269.19 1 .22E+02 1.22E+02 1.22E+02
CLEANUP LEVELS FOR SURFACE AND SUBSURFACE SOILS
SO:ZPOTSOIL
Subsurface INCREMENTAL RISK
Carcinogenic SOIL DIRECT TOTAL SOIL
Parameter INGESTION CONTACT RISK CONG. CLEAN UP LEVEL (mg/kg)
(mg/kg) 1E-06 1E-05 1E-04
AREA 1A
Benzene 1.G0E-11 1.G0E-11 7.000 4.38E+05 4.38E+06 4.38E+07
PAHs 6.70E-07 1.40E-06 2.07E-06 14. 710 7.11 7.11 E+01 7.11 E+02
AREA 18
Benzene 1.B0E-10 8.G0E-14 1.B0E-10 3.70E-02 205.46 2.05E+03 2.05E+04
•
CLEANUP LEVELS FOR GROUNDWATER
GW:ZPOTGW
Carcinogenic
Parameter Cleanup levels (mg/L)
1E-06 1E-05 1E-04
Benzene (Area 1 A) 1.36E-03 1.36E-02 1.36E-01 •
Benzene (Area 1 B) 1.69E-03 1.69E-02 1.69E-01
Non-Carcinogenic
Parameter Cleanup levels (mg/L)
1E-06 1E-05 1 E-04
Benzene (Area 1 A) 1.91 E-09 1.91 E-09 1.91 E-09
Chromium (VI) (Area 1 A) 1.56E-07 1.56E-07 1.56E-07
Lead (Area 1 A) 3.56E-09 3.56E-09 3.56E-09
Toluene (Area 1 A) 4.44E-06 4.44E-06 4.44E-06
Benzene (Area 1 B) 2.27E-09 2.27E-09 2.27E-09 • Lead (Area 1 B) 3.56E-09 3.56E-09 3.56E-09
CLEANUP LEVELS FOR GROUNDWATER
GW:ZPOTGW
Carcinogenic INCREMENTAL RISK
Parameter Inhalation Dermal Contact Produce Concentration
Ingestion Showering Showering Washing Ingestion TOTAL RISK (mg/L)
Benzene (Area 1 A) 1.10E-03 7.30E-04 1.50E-05 1.90E-05 4.60E-04 2.32E-03 3.150
Benzene (Area 1 8) 1.B0E-06 2.10E-06 4.30E-08 5.50E-08 1.32E-06 5.32E-06 0.009
Non-Carcinogenic RISK RATIO
Parameter Inhalation Dermal Contact Produce HAZARD Concentration
Ingestion Showering Showering Washing Ingestion INDEX (mg/L)
Benzene (Area 1 A) 9.00E+02 4.50E+02 9.40E+00 1.20E+01 2.B0E+02 1.65E+03 3.15
Chromium (VI) (Area 1 A) 1.40E+00 2.10E-03 2.60E-03 2.00E-01 1.60E+00 0.25
Lead (Area 1 A) 5.10E+00 7.40E-03 9.40E-03 1.90E+00 7.02E+00 0.025
Toluene (Area 1 A) 2.B0E+00 9.50E-01 4.00E-02 4.60E-02 2.70E+00 6.54E+00 29
Benzene (Area 18) 1.BOE+00 1.30E+00 2.?0E-02 3.40E-02 8.1 0E-01 3.97E+00 0.009 • Lead (Area 1 B) 3.10E+00 4.50E-03 5.60E-03 1.1 0E+00 4.21 E+00 0.015
• •
This document waa prepared by Roy F. Weston, Inc., expressly for EPA. It shatl not be released or disclosed, In whole or In pan,
without the express written permission of EPA.
Feasibility Study
Potter's Septic Tank Pits Site
Section: 6
Revision: 1
Date: April 1992
Pago: 7 of 11
• Alternative 1 -No Action -This alternative consists of no active remedial
actions but long-term monitoring will be performed.
• Alternative 2 -Institutional Controls -This alternative consists of monitoring,
removing site residences, restricting site access, and restricting site and
resource (groundwater and soil) use.
• Alternative 3 -Groundwater Recovery and Treatment -This alternative will
address active groundwater remediation only. Active soil remediation will not
be addressed but will progress only by natural processes (i.e. flushing to
groundwater and biodegradation).
• Alternative 4 -Soils Removal and Disposal -This alternative will consist of two
options based on protection of human health, considering risk levels of 104 ,
10-5 and 10-6. This alternative will not address groundwater remediation
actively.
• Alternative 5 -Soils Removal and Disposal with Groundwater Recovery and
Treatment -This alternative actively addresses both soil and groundwater
remediation goals. Options for the soil cleanup methods will be addressed
including the 104 , 10-5 and 10-6 risk based levels and the soils cleanup
standards to protect groundwater.
• Alternative 6 -Soil Stabilization and Containment and Groundwater Recovery
and Treatment -This alternative will address both groundwater and soil
remediation objectives. Soils will be stabilized to eliminate or minimize
direct contact with humans and contaminant migration to groundwater.
Options for the soil cleanup methods will be addressed including the 104 , 10-5
and 10-6 risk based levels and the soils cleanup standards to protect
groundwater.
• Alternative 7 -Soil Incineration with Groundwater Recovery and Treatment -
This alternative will address both groundwater and soil remediation
objectives. Soils will be excavated for incineration. Options for the soil
cleanup methods will be addressed including the 104 , 10-5 and 10-6 risk based
levels and the soils cleanup standards to protect groundwater.
• Alternative 8 -Soil Washing with Groundwater Recovery and Treatment -This
alternative will address both groundwater and soil remediation objectives.
Soil washing will be applied to remove contaminants of concern from the soil.
Options for the soil cleanup methods will be addressed including the 104 , 10-5
and 10-6 risk based levels and the soils cleanup standards to protect
groundwater.
B:\P2\P01TEAS\FS-SEC6.CWS
• •
This document was prepared by Roy F. Weston, Inc., expressly for EPA. tt shall not be released or disclosed, In whole or In part,
without the express written permisslon of EPA.
Parameter
1,1,l,TCA
Cblorobenzene
Benzene
Toluene
Ethylbenzene
Total Xylenes
TCE
2-Methyl
naphthalene
Naphthalene
2-Methylphenol
Methyl phenol
Phenol
2,4-
Dimethyl phenol
Chromium
Lead
Zinc
Iron
Barium
Cobalt
Nickel
Selenium
Vanadium
Aluminum
B:\P2\POTTEAS\FS-SEC7.CWS
TABLE 7-1
Feasibility Study
Potter's Septic Tank Pits Site
Section: 7
Revision: 1
Date: April 1992
Page: 10 of 74
SELECTED TREATMENT SYSTEM DESIGN PARAMETERS
EPA-OS EPA-09 MW-110/210 InDuent Feed
ug/L# ug/L# ug/L * Concentration, ug/L
500 5 5 253
500 4 5 252
3,500 9 1,900 2,070
30,000 5 12,000 17,002
2,600 5 1,800 1,602
28,000 5 19,000 17,168
500 5 5 253
13 5 52 17
150 5 490 158
73 5 20 42
170 5 130 108
80 5 25 46
150 5 58 86
180 550 160 300
29 6 34 22
47 27 . 35
28,000 44,000 60,000 38,667
180 46 200 139
2 2 36 8
110 31 36 71
3 3 . 3
20 5 240 52
8,600 2,300 100,000 21,733
• •
This document was prepared by FIDy F. Wemoo, Inc., exp<essly for EPA. ft shall not be released o, disclosed, in whole o, In part,
without the exprasa writ!en permission ol EPA.
# •
Parameter
Manganese
Calcium
Magnesium
Sodium
Potassium
TABLE 7-1
Feasibility Study
Potter's Septic Tank Pits Sita
Section: 7
Revision: 1
Dale: April 1992
Page: 10A ol 74
SELECTED TREATMENT SYSTEM DESIGN PARAMETERS
EPA-OS EPA-09 MW-110/210 Influent Feed
ug/L# ug/L# ug/L • Concentration, ug/L
240 34 280 178
26,000 7,600 33,000 21,033
11,000 2,800 9,600 8,033
300,000 46,000 120,000 185,333
5,500 2,800 9,000 5,183
indicates highest concentration for each parameter from all sampling rounds.
indicates highest concentration for each parameter between the two wells from all available analyses .
B:\P2\POTTEAS\FS·SEC7.CWS
• •
Thia document wu prepared by Roy F. Weston, Inc., expressly for EPA. It shall not be released or disclosed, In whole or In part,
without the express written permission of EPA.
TABLE 7-2
AIR STRIPPER DESIGN PARAMETERS
Feasibility Study
Potter's Septic Tank Pita Site
Section: 7
Revision: 1
Date: April 1992
Page: 14 of 74
Maximum Water Flow Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 gpm
Air Flow Rate . .. . . . . . . . . . . .. .. .. .. . . . . . . . . .. . .. .. .. . . . .. . . .. . . . . . .. . . . . . . . . . 350 cfm
Influent Water Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55"F
Packing Type ............................................. Jaeger Tripacks (2-inch diameter)
Packing Material .......................................................... Polyethylene
Packed Depth ................................................................. 30 feet
Column Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................. 2 feet
Air Pressure Drop ....................................... <0.1-inch water/ft (5 inches overall)
Maximum Projected Maximum Projected
Parameter Influent Concentration Effluent Concentration
(ug/L) (ug/L)
1,1,1-Trichloroethane 253 0.1
Benzene 2,070 1.7
Toluene 17,000 17
Ethylbenzene 1,600 23
Total Xylenes 17,170 22
Chlorobenzene 250 1.0
Trichloroethylene 253 0.1
Naphthalene 158 100
Note: Projected influent concentrations were conservatively .based upon the maximum concentrations from
representative wells. Actual influent concentrations will vary (be lower) and may decrease significantly
during the initial phases of operation. The effluent concentrations as related to influent concentrations
will decrease accordingly.
B:\P2\POTTERS\FS.SEC7.CWS
•
This document waa prepared by Roy F. Weston, Inc., expressly for EPA tt shall not be released or disclosed, In whole or in part,
without the express written permission of EPA
Feasibility Study
Potter's Septic Tank Pits Site
Section: 7
Revision: 1
Date: April 1992
Page: 36 of 74
7.6 ALTERNATIVE 6 -SOIL STABILIZATION/SOLIDIFICATION AND
CONTAINMENT WITH GROUNDWATER RECOVERY AND TREATMENT
7.6.1 Description
This alternative would consist of the stabilization/solidification (in situ or ex situ) of soils
that exceed selected action levels (levels corresponding to a standard to protect
groundwater, lxl0-6, lxl0·5, and lxl0-4 risk levels3), and groundwater recovery and
treatment. In situ stabilization/solidification treatment processes would be performed to
stabilize soils to an average depth of eight feet. This alternative would consist of the
following components:
• Performing a treatability study to determine effectiveness and implementability
of stabilization/solidification technologies.
• Excavation and off-site disposal of surface soils to allow for soil expansion upon
treatment. This would only be performed if an in situ technology would be used.
The amount of surface soil requiring excavation and off-site disposal would be
determined during the treatability studies. For the purposes of costing, it is
assumed that approximately 1 foot would require off-site disposal. The off-site
disposal procedures discussed in Alternative 5 are assumed to apply to these soils.
• In situ mixing of admix/soil, or removal and mixing of excavated soil inside the
area of the excavation footprint, and backfill of the excavation with the treated
soils. The backfill procedures identified in Alternative 5 are assumed to apply to
this alternative.
• Placing a low permeability clay cover over the stabilized/solidified, contaminated
materials to minimize the potential for leaching.
• Design, installation, and operation of a groundwater recovery and treatment
system as identified in Alternative 3. As in Alternative 3, action levels of 1, 5,
and 10 ug/L benzene will be used.
• Perform monitoring and inspections of the site for a period of 30 years afterwards.
Maintenance will be performed on an as-needed basis.
3 Action levels corresponding to 10-6, 10·5, and 10-4 risk levels are also based on a
hazard index equal to 1 for non-carcinogenic compounds.
B :\P2\f'OTTERS\FS·SEC7 .C:WS
fl
592-6178
}
/
oe Baldwin Ori"9
0 50 100 200
Approx. Scale In Feet
FIGURE 7-1 PROPOSED GROUNDWATER EXTRACTION SYSTEM
FEASIBILITY STUDY FOR THE POTTERS SEPTIC TANK
SERVICE PITS SITE SANDY CREEK, NORTH CAROLINA
•
• • UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IV
345 COURTLAND STREET. N.E.
ATLANTA. GEORGIA 30365
Ji,ily 30,. 1992
MEMORANDUM
Subject: Response to State of North Carolina's Comments on the
Baseline Risk Assessment for the Potter's Pit Site
Sandy Creek, North Carolina
From: Glenn Adams, Toxicologist ~'----c:.Zci<~~~·
Ground-Water Technology Support Unit
To: Darcy Duin, Remedial Project Manager
North Superfund Remedial Branch &j
Thru: David W. Hi.11, Acting Chief ;)(/_4 (',/
Ground-Water Technology Support Unit
I have reviewed the State of North Carolina's comments on the
Baseline Risk Assessment (BRA) for the Potter's Pits site. The
following comments are in response to the State's comments.
It should be noted that the first draft remedial investigation
(RI) which included the BRA was sent out for comment in August
of 1990 and the RI was finalized in October of 1991. Any
comments on the RI/BRA should have been sent to EPA during-that
time. Incorporation of comments nine months after document
finalization is inappropriate,•but would be entertained if the
comments would substantially alter the risk documents
conclusion. The comments on the BRA that were sent to EPA
asking for the BRA to be redone would not result in any
substantial changes in the BRA.
Response to Comment #1:
The permeability constant of 8 x 10-4 which was used in
the BRA is the one provided in EPA's Risk Assessment
Guidance for Superfund (RAGS) in Section 6.6.1 on page 6-34
and was appropriate at the time the document was written.
Changing this permeability constant now would not result in
any substantial changes in the results of the BRA.
Printed on Rccyc/eu P.Jpcr
• • -2-
Response to Comment #2:
Usually, when considering exposure via the inhalation of
contaminants during showering only the volatile organic
contaminants (VOCs) are considered because they are the
only contaminants that readily volatilize into the air.
Adding slightly volatile semivolatile organics to the
showering exposure route would not substantially effect the
ultimate total risk.
Response to Comment #3:
This BRA was done in August of 1990. The oral slope factor
for hexachlorobenzene from the HEAST (Health Effects
Assessment Summary Table) which was available then was
used. Even if this change was made at this time, it would
not result in any substantial changes in the results of the
BRA.
Response to Comment #4:
As stated in the response to comment #3, the values from
the HEAST which were available at the time the BRA was
written were used.
Response to Comment #5:
See response to comments #3 and #4.
Response to Comment #6:
The reference dose (RfD) for naphthalene came from the
HEAST which was available at the time the BRA was written.
It is just a coincidence that the RfD is the same value as
the RfD for carcinogenic PAHs.
Response'to Comment #7:
It is stated on page 8713 of the 1990 National Oil and
Hazardous Substances Pollution Contingency Plan (NCP) that
"EPA will set remediation goals for total risk due to
carcinogens that represent an excess upperb~und lifitime
cancer-risk to an individual to between 10-to 10-
lifetime excess cancer risk. A cancer risk of 10-6 will
serve as the poin4 of depgrture for these remediation
goals." This 10-to 10-cancer risk range is an
acceptable risk range for EPA while non-carcinogens whose
hazard index exceeds one (1) per target organ are normally
remediated by the Agency.
• • -3-
Response to Comment #8:
Exposure to ground water was not considered for the
forest/wetlands area because the Agency has determined that
this area ditl not contain land which is suitable for
residential pevelopment.
Response to Comment #9:
The areas at the Potter's site are mostly covered with
vegetation, therefore the inhalation of dust particles was
not considered.
Response to Comment #10:
See response to comment #8.
If you have any questions, please call me at x3866.
cc: Elmer Akin
• ,/:~'-,
(~ ltrjlil
\tz~~:~~-~:_,fl
•
State of North Carolina
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
Mr. Greer C. Tidwell
Regional Administrator
US EPA Region IV
345 Courtland Street, NE
Atlanta, GA 30365
July 29, 1992
Subject: Conditional Concurrence with the Record of Decision
Potters Septic Tank Service Pits
Maco, Brunswick County, NC
Dear Mr. Tidwell:
William L Meyer
Director
The State of North Carolina has completed review of the attached Record of Decision and concurs with the selected remedy subject to the following conditions.
l. All surface and subsurface soils must achieve cleanuo levds based on not exceeding a collective excess carcinogenic risk of l x io-6 or a Hazard Index
of 1. If, after remediation is complete, the total residual risk level .exceeds
I x l0-6, the site will require deed ,ecordation/restriction to document the
presence of residual contamination and possibly limit the future use of the
property as specified in NCGS 130A-3 I0.8.
2. State concurrence on this Record of Decision and the selected remedy for the site is based :-olely on the information contained in the Record of Decision.
Should the State receive new or additional information which significantly
affects the conclusions or remedy selection contained in the Record of Decision, it may modify or withdraw this concurrence with written notice to EPA Region IV .
. . -------------· ... ·.
• •
Mr. Greer Tidwell
7-29-92
Page 2
3. State concurrence on this Record of Decision in no way binds the State to concur in future decisions or commits the State to participate, financially or otherwise, in the clean up of the site. The State reserves the right to review, comment, and make independent assessment of all future work relating to this site.
4. A proposal of cleanup levels from groundwater should not exceed the North
Carolina NCAC Title 15A Subchapter 2L groundwater standards unless a variance is obtained from the Division of Environmental Management. You may direct your requests for a variance to Mr. Preston Howard, Director, Division of Environmental Management, PO Box 27687, Raleigh, NC 27611.
I have spoken with Bill Jeter with the Division of Environmental Management regarding using the MCL instead of the 2L groundwater standard for ethylbenzene. Mr. Jeter felt that there would not likely be a problem in receiving a variance from the ethylbenzene standard because the standard is
based on taste.
The State of North Carolina appreciates the opportunity to comment on the Revised Draft Record of Decision for the subject site, and we look forward to working with EPA on the final remedy.
cc: Michael Kelly
Curt Fehn
Darcy Duin
Attachment
Sincerely,
[/vvvlJfzc. /,UrJ_,c,/
Charlotte Jes neck, Head
Inactive Hazardous Sites Branch
NC Superfund Section
• • UNITED STATES ENVIRONMENTAL PROTECTION AGENCY . ·a;;;n
REGION IV RECE\V-...,
4WD-NSRB
July 28, 1992
Charlotte Jesneck
NCDEHNR
Superfund Section
401 Oberlin Road
345 COURTLAND STREET. N.E.
ATLANTA. GEORGIA 30365
Raleigh, North Carolina 27605
JUL a O 1992
SUeERftlNDSf£llON
RE: Response to Comments on the Proposed Plan and the Draft Record
of Decision
Potter's Septic Tank Service Pits Site
Sandy Creek, North Carolina
Dear Ms. Jesneck:
Below are EPA' s responses to North Carolina's comments on the
Potter's Pits Proposed Plan and Draft Record of Decision.
PROPOSED PLAN
Response to comment #1 and #2:
Attachment #1 includes a memo to the site file dated May 1, 1992 on
Additional Information for the Feasibility Study Report. This memo
provides a description of the Low Temperature Thermal Desorption
Technology. I have also included a detailed analysis of this
alternative based on the nine criteria similar to how the other
alternatives were analyzed in the FS. A cost breakdown is also
shown as part of the memo and has been included in the ROD. Please
note that the clean-up standards outlined in the ROD have changed
from the clean-up standards calculated in the memo.
Response to comment #3:
Attachment #2 is a table from the FS showing the contaminants of
concern, their associated risk, and clean-up level. In the
Proposed Plan, carcinogenic PAHs were not included in the
contaminants of concern because the carcinogenic risk for
carcinogenic PAHs in soils fell right outside the acceptable risk
range (E-04 to E-06) and at that time EPA did not feel that the
carcinogenic PAHs posed a problem.
As you will note, in the ROD ( second draft) a soil clean-up
standard have been established for carcinogenic PAHs. The soil
clean-up standard is .011 ppm. Carcinogenic PAHs do not pose a
problem to human health or the environment in groundwater;
Printed on Recycled Paper
•
therefore groundwater clean-up standards for carcinogenic PAHs were
not established.
Response to comment #4:
This comment concerns the additivity of the carcinogenic risk
resulting from the soil clean-up standards at the Potter's Pits
site. The baseline risk assessment (BRA) showed that the soils at
the site were within EPA's acceptable risk range of E-04 to E-06 or
less than a HI of 1 for direct exposure except for lead, zinc, and
carcinogenic PAHs ( as indicated in Attachment #2). As described in
Section 6.7 (Risk Assessment Summary), all the soil remediation
standards which were developed for this site are based on the
protection of groundwater except for zinc and carcinogenic PAHs.
Therefore there is no need to consider the additivity of the
carcinogenic risks for the soil remediation standards since they
are all based on protection of groundwater (except for zinc and
carcinogenic PAHs) and are within the acceptable limits.for direct
exposure as shown in the baseline risk assessment.
Please note that it is stated on page 8713 of the 1990 National Oil
and Hazardous Substances Pollution Contingency Plan (NCP) that "EPA
will set remediation goals for total risk due to carcinogens that
represent an excess upperbound lifetime cancer risk to an
individual to between E-04 to E-06 lifetime excess cancer risk. A
cancer risk of E-06 will serve as the point of departure for these
remediation goals." On page 8848 of the NCP, it is stated that
"The E-06 risk level shall be used as the point of departure for
determining remediation goals for alternatives when ARARs are not
available or are not sufficiently protective because of the
presence of multiple contaminants at a site or multiple pathways of
exposure." The clean-up standards selected for the Potter's Pits
site are set at EPA's point of departure of lE-06, if Federal or
State ARARs were not available. The cumulative risk resulting from
these clean-up standards which are set at ARARs or lE-06 risk
levels do fall within EPA's acceptable risk range.
Another part of this comment deals with TCLP. As stated in Section
9.2, TCLP concentrations have been set using the Federal standards.
As described in this Section, if the soil fails TCLP, then it will
be treated as a characteristic hazardous waste. If the soil meets
the Federal Standards for TCLP outlined in the ROD, then the soil
can be placed back from where it was excavated and will not need
further treatment.
Response to comment #5:
It has been determined in the baseline risk assessment that
carcinogenic PAHs are not a problem in groundwater. Again, the
State's concern is that additivity of risk was not taken into
consideration for the groundwater remediation standards. This is
not completely true. The groundwater remediation standards were
set at the Federal or State ARARs when available and if no ARARs
•
are available, then the standards were set at the chemical specific
lE-06 risk level. These groundwater remediation standards do not
have to be adjusted, as long as the sum of the risks related to
these clean-up standards are within EPA's acceptable risk range.
Response to comment #6:
As stated in Section 9.1 (second draft) of the ROD, the treated
groundwater will be discharged into Chinnis Branch on site. Since
the discharge will be done on site, no permits are required;
however, the substantive requirements of all applicable surface
water discharge requirements will be met (NPDES permit).
DRAFT RECORD OF DECISION
Response to comment #1:
This comment will be addressed at a later date.
Response to comment #2:
The Responsiveness Summary was sent to NCDEHNR on Wednesday July
22, 1992 (Federal Express) for review.
Response to comment #3:
The figures indicating the proposed amount of soil which will need
to be remediated were eliminated. Also any reference to the amount
of soil to be excavated and treated was deleted. For cost
purposes, it is indicated in the ROD that approximately 10,100
cubic yards of soil will be excavated and treated. This number was
simply used for cost estimating and the exact amount or location of
the soil which needs to be treated is not formally indicated as it
will probably change during the design phase.
Response to comment #4:
The treatment system oulined in the ROD will treat all of the
contaminants of concern. The only semi volatile ( SVOCs) contaminant
of concern is Napthalene. This SVOCs is one of the most volatile
SVOCs; therefore, it is EPA's belief that this contaminant will be
treated with the groundwater treatment system proposed.
Response to comment #5:
This comment will be incorporated into the ROD and will read "Since
limited sampling was conducted in Area 3 during the Remedial
Investigation, a soil boring will be installed near MW-104 and
samples collected by compositing 2.5 foot intervals continuously to
12.5 feet below ground surface (5 samples). These samples will
have a complete TCL/TAL analyses performed."
•
Response to c_omment #6:
As discussed with the State in a conference call earlier this year,
EPA believes that Ratttlesnake Branch is too far away from the site
to attribute any contamination that might be found there to
Potter's Pits. EPA is aware of the 1976 oil spill that occurred at
Potter's which sent contamination down to Rattlesnake Branch;
however since 16 years have gone by since the spill, it would be
difficult to trace the contamination back to Potter's especially
enlight of the fact that the contaminants of concern are the common
BTEX constituents which are used in a variety of manufacturing and
domestic uses.
Response to. comment #7:
Please read response to comment #4 and #5 under the responses to
the Proposed Plan.
Response to comment #8:
In Section 9. 2 ( second draft of the ROD) in the second paragraph, it
states "Confirmation sampling shall also be conducted following
excavation and prior to backfilling treated soils to ensure the
underlying soils and the treated soils meet the appropriate soil
clean-up standards."
It is also stated further in this section what exactly will be done
with the soil after treatment.
Response to comment #9:
The Clean-up standards that have been established for soils are
based · on the protection of groundwater except for zinc and
carcinogenic PAHs as described in Section 6. 7 of the ROD. The
clean-up standards are protective of human health and the
environment.
Please do not hesitate to contact me at [phone] if you have
any questions regarding these responses. A conditional
concurrence letter was received and hopefully these comments will
begin to answer any remainding questions you may have regarding the
ROD. I will fax the remainding responses to the RI Addendum and
Feasibility Study comments tomorrow.
Snrely, j)~
~~
Re~~~i~P~roject Manager
cc: Curt Fehn, EPA
Attachments
DATE TIME
07/28 16:21
•
MESSAGE CONFIRMATION
TX-TIME
03'44"
DATE:07/28/92 TIME:16:25
ID:EPA REGION IV WA
DISTANT STATION ID MODE
G3-S
PAGES
005
RESULT
OK
ATTACHMENT 1 • UNITED ST ATES ENVIRON MENTAL PROTECTION AGENCY
REGION IV
345 COURTLAND STREET. N.E.
MEMORANDUM ATLANTA. GEORGIA 30365
DATE: May 1, 1992
SUBJECT: Additional Information for the Feasibility Study Report Potter's Septic Tank Service Pits Sandy Creek, North Carolina
Darcy Duin ~~
Remedial Project Manager
FROM:
TO: FILE
The Second Draft of the Feasibility Study Report was submitted for Agency review on April 9, 1992. This Report will be the Final Feasibility Study Report for the above referenced Site. This Report plus the following information was used by the Agency to decide which remedy would be the most appropriate for this Site. This information has been included in the attached pages and consist of the following topics:
Attachment 1: Memo date April 16, 1992 on the development of the soil cleanup levels.
Attachment 2: Additional Soil Alternative: Low Temperature Thermal Desorption.
Attachment 3: Information on Thermal Desorption
Printed on Recycled Paper
MEMORANDUM
DATE:
SUBJECT:
FROM:
TO:
•
ATTACHMENT 1
April 16, 1992
Soil Cleanup Levels
Potter's Septic Tank Service Pits Site
Sandy Creek, North Carolina
Darcy Duin
Remedial Project Manager
FILE
The soil cleanup levels that have been calculated in the Feasibility Study Report for the Protection of Groundwater were calculat.ed using the federal MCLs not NCGWQS. Using the same method outlined in a memo to me from Bill O'Steen dated November 19, 1991, the soil cleanup levels were recalculated using North Carolina's Groundwater Standard. These levels are:
N.C. Groundwater Soil Remdiation Compound Estimated Kd Protection Standard Goal
Benzene 1.92 1 ppb .0019 ppm Toluene 3.41 1,000 ppb 3.4 ppm Ethylbenzene 8.1 29 ppb .235 ppm xylenes 8.67 400 ppb 3.5 ppm naphthalene 60 30 ppb 1.8 ppm chromium 1945 50 ppb 97.2 ppm lead 1695 15 ppb 25 ppm
The practical quantitation limit for Benzene is 10 ppb for soil. Therefore, the soil remediation goal for Benzene will be 10 ppb not the 1.9 that was calculated above.
• • ATTACHMENT 2
LOW TEMPERATURE THERMAL DESORPTION
Description:
Under this alternative, contaminated soil and debris would be
excavated and treated utilizing low temperature thermal technology.
Treated soil will be tested for RCRA characteristics, LDR
treatability variance levels, and compliance with other treatment
requirements and returned to the excavated area if found to be
non-hazardous and consistent with the cleanup criteria. The volume
of contaminated soil and debris and the excavation procedures are
identical to those described in Alternative 5 of the FS Report.
Treatment will consist of volitilizing the organic contaminants at a
temperature generally less than 1000 F with the off-gases being
captured and treated to prevent the release of contaminants. Off-gas
treatment varies depending on the vendor, but usually consists of:
(1) thermal oxidation in a secondary thermal oxidation chamber
similar to incinerators; or (2) condensing and concentrating the
organics into a significantly smaller mass for further treatment
(incineration); or (3) passing the off-gases through activated carbon
to adsorb in the contaminants and then regenerating the carbon.
The off-gases will pass through an air pollution control system
consisting of cyclonic separators and baghouse and scrubbers to
remove particulates and HCL either prior to or after treatment of the
off-gases, depending on the treatment system. Scrubber blowdown
water can either be reprocessed through the system or treated with
activated carbon and then used to quench the treated (hot) soil.
Typically, air emitted to the atmosphere is passed through a bed of
activated carbon to insure that it is free of contaminants.
Treated soil will be analyzed for RCRA hazardous characteristics and
land disposal restrictions and disposed back into the excavated areas
if found non-hazardous. If hazardous due to inorganics (metals), the
treated soil must undergo additional treatment, such as
stabilization/solidification, and retesting prior to disposal. If
hazardous due to organics, the soil will be reprocessed to remove the
organics in it to below toxic levels.
Any stockpile of contaminated material must meet RCRA storage
requirements to prevent further contamination of the environment.
The thermal desorption system would be located in a central
location. The major costs associated with this alternative are for
the excavation of contaminated soil and debris, treatment of the soil
and returning the soil to the excavated areas. The cost ranges from
approximately $50 to $225 per ton, and is dependent on the type of
system /vendor. Additionally, ·some price estimates included the post
treatment costs, such as regeneration of carbon.
I:
• • PROTECTION OF HUMAN HEALTH AND ENVIRONMENT
The ultimate fate of the organic contaminants is thermal destruction. The place where the destruction takes place varies depending on the system. Final destruction can occur at a RCRA facility, on-site, or at a carbon regeneration facility. Because the organic contaminants are separated from the soil, there should be little, if any, organic ash residue remaining after final destruction. Treated soils must pass RCRA hazardous characteristic testing and meet the State requirements for disposal of solid wastes. Thus, implementation of this alternative would provide sufficient protection to human health and the environment.
COMPLIANCE WITH ARARS
Low temperature thermal desorption/separation technology is not considered to be the same as incineration, thus Subpart 0, 40 CFR 264 regulations are not applicable. However, Subpart O regulations may be deemed relevant and appropriate. All exhaust emissions must meet CAA requirements. The treated soil must pass RCRA hazardous characteristic testing and also meet State requirements prior to on-site non-RCRA disposal.
LONG-TERM EFFECTIVENESS AND PERMANENCE
This alternative provides long-term effectiveness and permanence by thermally destroying the organic contaminants. Most inorganic contaminants are not oxidized during this process and will tend to remain bound to the soil. Any residual material containing elevated levels of inorganic consituents (metals) will be
stabilized/solidied. All treated soil must pass RCRA hazardous characteristic testing and meet State requirements prior to on-site disposal. This will effectively provide long-term removal of these contaminants from the environment.
REDUCTION OF TOXICITY, MOBILITY OR VOLUME THROUGH TREATMENT
Removal (desorption/separation) of the organic contaminants from the soil with ultimate thermal destruction will reduce the toxicity and volume fo the treated material. As mentioned above, any material which is hazardous due to inorganics will be stabilized/solidified, thus greatly reducing the mobility of those contaminants. Because the treated soil must pass RCRA characteristic testing and State requirements prior to on-site non-RCRA disposal, further contamination is unlikely. Implementation of this alternative meets the intent of the NCP to use treatment alternatives to reduce the long-term management of hazardous wastes.
SHORT-TERM EFFECTIVENESS
During the implementation of this alternative, truck traffic, noise, exhaust, and fugitive dust will increase during the excavation of the contaminated material and installation of the groundwater monitoring wells. Additionally, organic vapors may be released as the areas are
• • excavated. All of these effects will have a negative short-term
impact on surrounding human health and the environment. This impact
can be minimized by utilizing dust and vapor prevention controls.
Loaded trucks exiting the sites must be completely covered to prevent
the release of contaminated material.
The estimated time required to complete the soil remediation with one
mobile LTTD unit is approximately 4 months (if operating 24 hours a
day), assuming a process rate of 5 tons per hour. This process rate
varies depending on the vendor and the system.
IMPLEMENTABILITY
This alternative can be readily implemented depending on the
availability of a thermal desorption unit.
COST
Capital costs:
Project Plans
Erosion/Sediment
Control
Mobilization
Fence
Residence relocation
Excavation
Treatability Study
Thermal Desorption
Stabilization
(20%)
Off-Site Disposal
Verification
Backfill
Regrade/Reseed
Capitol, Subtotal:
Engineering (25%)
Contingency (25%)
Total Capital:
UNITS
1
300
1
1,600
1
10,100
1
13, 635
2020
2
60
10,100
4
..,
Cu.Y
tons
Cu.Yd
trucks
if OF UNITS
40,000
10
10,000
15
10,000
10/Cu. Yd.
150,000
170/ton
100/Cu.Yd.
3600
350
10
1500
COSTS($)
40,000
3,000
10,000
24,000
10,000
101,000
150,000
2,317950
202000
72000
21000
101000
6000
2,993,150
748288
935360
$4,676,798
• ATTACHMENT 3 • 3.0 THERMAL DESORPTION
3. I TECHNOLOGY DESCRIPTION
Thermal desorption technologies consist of a wide variety of processes that vaporize
volatile and semi-volatile organics from soil and sludge. The processes are planned and designed
to avoid combustion of the contaminants in the primary unit, resulting in several advantages.
After desorption, the volatilized organics may be subsequently treated in an afterburner or
condensed for reuse or destruction. The types of air pollution control equipment (APC) needed
to treat the exhaust gases will vary depending on the technology and the nature of the
contaminated media. Dust and particulates may be controlled with cyclones, baghouses or venturi
scrubbers; small amounts of acid vapor may require scrubbing; and residual organics may be
condensed and/or captured in activated carbon adsorption units.
Although there are no generally accepted definitions for grouping the different types of
thermal desorption. the following three terms may be used to describe the different processes:
Directly heated desorption
Indirectly heated desorption
In situ steam extraction
Soils contcining organics
Heol (300 F-1200 F)
Thermal
Desorption
3-1
I Treoted reS1duol
I Recovered contam,nonts •
Weter trom AF'C •
Treated offgases
Particulate control dust
Spent carbon •
1
• • 3.1.1 Directly Heated Desorplloa
Direct-fired systems use a fuel burner as a heat source which may be either internal or
external to the primary soil-heating chamber. Internally fired units resemble rotary kilns.
operate at temperatures of less that 800'F (426'C), and have generally been limiied to use for the
treatment of non-chlorinated organics such as petroleum spills. Exhaust gases from the rotating
cylinder pass through a dust-collection system prior 10 secondary combustion. OH '.late rials, Inc.
operates a low temperature direct-fired desorber. Canonie Environmental has a low temperature
thermal aeration system, which consists of a rotating dryer that heats incoming air from 300 to
600'F (148 to 315'C) by an external name. The system forces heated air counter-current 10 the
now of soils in a rotary drum dryer. The system can be used for chlorinated wastes with :arbon
adsorption recovery of the ::eated organics.
3.1.2 ladlrectly Heated Desorption
Indirectly heated systems transfer heat through metal surfaces to the waste. Indirect
heating produces a lower volume of exhaust gas which results in a low loading for the exhaust-
gas treatment and air-pollution°control systems. This also helps to control particulate carry-
over. Vaporized contaminants are removed from the thermal processor using a sweep gas with
low oxygen content to prevent oxidation (combustion and explosion). Desorbed organics may be
condensed and/or removed by carbon adsorption. These systems can be further characterized by
their operating range, with approximately 600'F serving as a breakpoint. Systems operating at
less than this temperature are designed for volatiles and systems above this temperature are
intended for semi-volatile organics and PCBs. It should be noted, however, that semi-volatile
organics may also be removed at the lower operating temperature range (below their boiling
point) as a result of stripping in the presence of water vapor and/or volatiles.
Examples of developers of this technology at the lo.,.,·er operating temperature range
include Weston Services, Inc. and the U.S. Army Toxic and Hazardous Materials Agency
(USATHAMA). These units consist of a low-temperature thermal-stripping process, which uses
a hollow-screw mixer that is filled with hot oil to heat the soil 10 approximately 450'F (:32'C).
Two examples of technologies at higher temperatures (>600'F)(3 l 5'C) are Chemical Waste
Management's X0 TRAX System and SoilTech's AOSTRA Taciuk Processor. Both processes
recover contaminants for subseQuent recycling or destruction. The x•TRAX system uses a
nitrogen atmosphere to keep the process oxygen free. Waste is treated in an indirectly heated
rotating dryer at tempera.tures ranging from 600 to 900'F (315 to 482'C). The volatilized organics
are carried to a gas treatment system that condenses and recovers the contaminants. The Taciuk
3-2
...,
• •
process consists of a preheating chamber which opera:es at 300 to 6Q0•F causing the v3.pori;:3cion
of water and light hydrocarbons. A second stage involves heating at temperatures up to \, l S0°F
to cause vaporization and pyrolysis of heavy hydrocarbons. The desorbed hydrocarbons are then
recovered in a condenser.
3.1.3 In Situ Steam Extraction
This process uses hollow-stem drills to inject steam and hot air into the ground. Volatile
organics are stripped from the soil (or ground water) and collected in a shroud at the surface.
The technology is especially applicable for volatile contamination near the surface (where vacuum
extraction is less effective). Although not generally applicable for semivolatiles. some removal
may take place. Toxic Treatments (USA) has used their unit to treat soil at a state Superfund
site. Steam (at 450'F) (232"C) and hot air (at 300'F) (148'C) are injected through counter
rotating drills up to 30 feet in depth. Volatile contaminants and water vapor are collected and
removed from the off-gas stream by condensation.
3.2
3.3
3.4
TECHNOLOGY STATUS
• This technology has been selected for 17 Superfund sites.
• Three PRP sites in Region I have been remediated by Canonie
Engineering.
APPLICA no:--
• Boiling points for selected compounds are given in Exhibit 4. These are
given for comparative purposes and most wastes will require treatability
studies to confirm removal levels. Removal efficiencies may vary widely
for similar soils.
• Thermal desorption is appropriate for both high and low concentrations of
contaminants.
• See the article on StJtus or Thermal Remediation in the chapter on
Incineration !Chapter :.O).
TECHNOLOGYSTRE:--GTHS
•
•
Lower temperatures eliminate volatiliz.ation of some meta! compounds
{lead, cadmium. co~;,er. and zin.:J
These Processes-opente at lower temperatures rhan incinerat1or. a:iC so use less rue!.
3-3
3.5
3.6
3.7
• •
• Concerns with products of incomplete combustion are eliminated b~
avoiding combustion in the primary desorbing unit.
• The technology has the ability to separate and recover concentrated
contaminants which may then be taken off -site for treatment.
• Decontaminated soil still retains some organics and soil properties It is not
ash.
TECHNOLOGY LIMIT A TIO NS
• The technology is not appropriate for inorganic contaminants.
• Although thermal desorbers operate at much lower temperatures than
incinerators, some metals (i.e., mercury, arsenic) may volatilize during
treatment.
POTENTIAL MATERIALS HANDLING REQlilREMENTS
• Excavation is required for desorber units.
• Dewatering may be necessary to achieve acceptable soil moisture content.
(The cost of desorption increases as the moisture content increases.)
• The material must be screened to remove oversized particles.
• Size reduction may be needed to achieve feed size required by the
equipment.
• The pH may be adJusted to achieve a pH between 5 and 11.
WASTE CHARACTERISTICS AFFECTING PERFORMANCE
• Temperature and residence time are the primary factors affecting
performance.
• Wastes with high moisture content significantly increase fuel usage.
• Fine silt and clay may result in greater dust loading to the downstream air-
pollution-control equipment, especially for directly heated systems.
• The volatility of the targeted waste constituents will be the primary factor
that affects treatment performance. A good indicator of volatility is the
pure component boiling point (see Exhibit 4). It is important to recognize,
that almost all hazardous wastes are mixtures of various organi:
constituents (both hazardous and non-hazardous) and these other
constituents often have a significant impact on the actual removal of the
specific compound from that matrix. Removal ma, be achieved at
temperatures bel_ow the boiling point.
3-4
• •
3.8 EXHIBIT I -WASTE CHARACTERISTIC TABLE
Wa.ste Type: Solis and Sludaes
Technoloay: Low Temperature Thermal Strippina
Characteristics
lmpactlna Process
Fea.slblllty
Presence of:
• Metals.
• Inorganics
• Less volatile
organics
pH<5,>ll
Presence of mercury
(Hg)
Unfavorable soil
characteristics:
• High percent of clay
or silt
• Tightly aggregated
soil or hardpan
• Rocky soil or glacial
till
• High moisture
content
Rea.son for Potential Impact
Some process effective only for highly
volatile rganics !Henry's Law Constant
>3 x 10· atm-m /mole). XTRAX system
can treat organics with boiling points up
to about 800'F ( 426'C)
Corrosive effect on system components
Boiling point of mercury 670'F (356'C)
close to operating temperature for process
212 to 572'F (100 to 300'C).
Fugitive dust emissions during handling.
Incomplete devolatilization during
heating.
Rock fragments interfere with processing.
High energy input required. Dewatering
may be required as pretreatment.
Data
Collection
Requirements
Analysis for prioritv
pollutants
pH analysis
Analysis for mercury
Grain size analysis
Soil sampling and
mapping
Soil mapping
Soil moisture content
Source: Technology Screening Guide for Treatment of Soils and Sludges EPA/540.'::-881004 ( l 988)
3-5
3.9 !IBIT 2 -DATA FROM SEMI-ANNU,STATUS REPORT
Selection Frequency*
6
Th erma ID esorotio n
5 -
4
/
NUMBER
of TIMES 3
,, r ..., •
SELECTED
2
_..., , V
, .J f'
0 .J
,
84 85 8 6 87 88 89 90
FISCAL YEAR
' Data derived from 1982 · 1990 Records of Decision ( RODs ) and an?icip,ated design and
constrvction activitiss. September 1991
Contaminants Treated By Thermal Desorption
Number
or
Supertund
Sites
voes PCBs PAHs PCP/Other SVOCs
' Dara derived from 1982-1990 Records of Decision (RODs) and anticipat9d design and consrrue1ion
activities. At some si'fes, the treatment is for more than ons major ccntaminant.
3-6
•
J.10
E] Si If' Iii-, Stall",
Aegion (ROO Oatf')
1 rannon [nginrc, ing/
Br 1dgew&tf'r, •• <03/.\1/88J
1 Mc-. in, "'. (Ol/?2/8\)
1 Ott at i & GO'iS, NH
(01116/81)
1 Rf' -sot ve, ••• (09/24/07)
Also Sf'f' Df'rhlo, inat ion
2 AmericBn Thermo-.tat, " (06/29/90)
2 Caldwf'I I Trucking, NJ, .
02 <09/ZS/86)
EXIIIIIIT J -INNOVATIVE TREATMEi>jT TECIINOLOGIF.S: SEMI-ANNUAL
STATUS REPORT
Thennal Desorption
S~r if ic s i ''" Jlltfflia Key Contaminants Status Technology De..,,_, ipl ion (Quantity) lreate-d
lh•~I Aeration (hf'111ical l.laste Soll (11,BO voes (Benzene, ICE, •rd Project Handling, cyl Vinyl Chlo,.ide) cOffllleted; Storage, ' ~rational lncinl'ration 5/90 10/90 facility
Jherll'iill Aeration \lao;te Storeqe, So ii (11,456 voes (TCE, e' x > Projrct fran-;fer, cy) coq:iletlPd; 0 i '-poSal Operational fee i Ii t y 7/& 2/87
Thennat Aeration o,~ Soi I (16,000 voes ( ICE, PCE, 1,2-DCA, Project Reconrii r ion· CV) 11nd 8f'Olf'~} c~leted; inq F ac i Ii ty Oper11t i on11l
6/89 -9/89
Rotnry Thermal ChNnical Soi I (22,500 PCBs Prf'des ign; w•TRAk• Oesorber Rer I &lnBI ion cyl Pl lot test {Df'chlor inat ion of. f IIC i I it y plerned for ,esi~es) F•ll 091;
Design
coq,let Ion
pl11rned 1991
lhermal Df'sorption Thermostat Soil (6,500 voes (PCE, ICE, OCE, •rd In design; Manufacturing cy) • Sf'difl"ltnts Vinyl Chlori~) Design
(.JOO cy) c~letion
planned Spring .. ,
Low J~rature Unpermi t ted Soi I (20,000 voes (ICE, PCE, and TCA) In design; Vaporiution Septic Uaste cy) Design
f BC i Ii I y c~letion
plllrned Spring ,92
3-7
Contacts I isted ar" EPA regional staff unltss olherwic;.e indicaled.
lead Agency and Contacts/
l(eat-nt Phone
Contractor (II
avail able)
PRP L"ad; Canonie 0.-. Coughl In
Engineering 617·S7l·96·
FIS UJ-96
PRP Lrod; Canonie Sheila Eck,..n
Engineering 617·571-5761,
JIS8Jl·1764
PRP teed; C11nonie Stephffl C11l<kr
Engi~ering 617-571-9626
rts 8H· 1626
PRP Lead/ torffllO Th11ntu
Ni•ed FlTlding; 617·221-5500
Chnilc11l Uaste flS ftH-1500
Nanagf'fflf'nt, Inc.
flTld Lead ch,iuos 1•1-212-264-571)
flS 264-H1J
hr,d lead Ed f innf'f ty
212-264-1555
r IS 261. · 1555
lhermal Desorption
LJ Sit,-NARW", SI atf', Sf-WC if ic Si II" "rdifl kf'y Contaniinants EJ lead A gene y and Contacts/
Af'g1on (ROO Ontr) lf'chnology Dt'-.n 1pt ion (QuAnt ity) Tuatl"d frf'at-,ll Phon,
Cont rector (If
■val lablf')
l CI arNnOnt Polyrht'fflical, lh.r•l D•sorpt ion ChN11ical Soi I (1,600 DDT, D00, DOE, voe, In design; hn:t L•ad; USACE Carlos I. ·-· NJ (09/28/90) facility cy) (DC£, PCE, ICE, end Oulgn 212·264·5616
lol~ne), svoe, c~let ion FTS 26'·5616
(Bf'nzoic acid, Bis(2· plvned
ethylhe•yl)phthalate, Winter '92
Butyl be-nzyl phthal■te,
Di-n-butyl phthalate,,
Naphthalrnr, and PCP),
ard PAHs
(Benzo(a)....,rrnr)
2 fulton Terminals, NY Low l""f)f'raturr form,pr Waste Soi I (i,,000 voe, (Mylene, Styrene, Prednign PRP lead Chrh1os 1s,-,.
(09/19/89) lhermal lreatl!W'nt IRnk farm cy) ICE, EthylbNilHW", 112·264-HU
lolue-™°) flS 264-571'
2 Maralhon Baltf'ry, NY. Enhancrd former Battrry Soil (85,000 voes (PC£' Tol~nf', and Predeslgn fund Lt-ad P• lames
(09/10/88) Volatilization Manufacturrr cy) ICE) 212-264-10}6
FIS 264· 1D16
2 "'etal tec/Arroc;y<,tNTI'>, Low l~raturr "'rt al Soi I (9,000 voes (ICF) In design; flld Lead; USA.CE JI■ Bely (mACE)
NJ (06/30/86) lhe111\81 Treatment "'&nufacturing <y) DHign 816-426-5211
c011plet ion
planned Sun'ftrr
'91
2 Aeirh farms. NJ Erl'tancf'd Uncontrol le-d Soi I (I, 120 voes and Seaivoletiles Pl lot studies PRP Lead Gary Ad .. lewlc1
(09/30/88) Vol al ii ization Mas1e Disposal cy) pl .,...,-.ed for 212-26'o· ~92
early 092; FIS 264-T'S92
design
COdlplel Ion
plar.-.ed: rat I
'92
2 Sarf!f'y Far•, NY Low lt.'ft'J)eralurf' Jndustr ial end Soi I <Z, 36S voes (Bl"'nzene, But~, Predesign; f l6ld l r1trl a:e..-in Millis
(09/Z7/90) lherll\81 Treatment MtJ1icip.:il 1:y) Chlorofor•, Design 212-264 8777
L andf i 11 Methylpentanooe, lCE, c011plet ion FIS 264-8777
and loluenf') pl•rwwd:
Spring '91
NolP: Cnnt,ilfls I i~lf'd a,e fl'A ,,-qiona\ staff ,,.,1'"°'' olherw1.;p indicalr-d.
Thermal Desorption
EJ . Sil~ Naml', SIOIP, Sp«-cific Sitr HPdio K"Y Contaminants Stetus Lead AgPncy and Contacts/ Rrgion (ROO OatP) I "l·hnot ogy Df'scription (Quant i ly) frf'atl!'d lrf'atnrf"lt Phone
Cont rec tor {if
available-)
2 \Jal dirk At'roo;;pacf' low r~raturr Manuhr tur ing soil (2,000 vocs (JCE and PCE) In design; hn:t l"l!td USACE Contracts Or,nc"-., .,. lherNI lrrat.-nt and cy) Opsign IKhnlc■I II. (09/?9/87) El re t ropl at -c~lrtlon Willi• Nch ing of Pie~ planned [phone] Parts October '91 Contr■cl l•s~•:
Susan Andu■on
[phone]
4 \JamrhNn, sc• low l~r-ature-rorfflt."r Oyf' soi I (2,000 vocs (BlX) In design; PRP lud Ge-orge Reedy (06/ J0/88) lhrrmal Trratll'N!'nt Manufacturing cyl DHign 404-147-7791 Plant c~lrtlon FIS 257· 77'91
plerried Fall
•01
s Outboard low ll!'ffperature-Marin. soi I. PCBs In design; PRP lt"ad; Canonlr Cindy Nolan Mari~/\Jaukrgan Hai bor, thermal F11tract ion Prod.Jets Se-diments Orsign Engineer-Ing 11l·M6·0400 ll • (laciul Process) Manufacturing (16,000 cy conplet ion FIS M6·0400 ( OJ/ 11 /89) conbined) pl.-ned Fal I
'94
s Untvf'rs1ty of lhermel Desorption Unive-rsily soi I (6,100 PCBs In design; PRP leed·State D•rre-11 °"'"" Minne-<:.ota, "" (fun, Incineration IJac;tes cy) • Debris De-sign Oversight :51l·M6-7089 (06/11/90) of PCB Vap:,rs) (160 <y) coq>letlon FIS M6·4089
pl..-...d D•vld DouglH (Mlf)
Fall '92 612·296-7818 •
8 Manin Marietta (Oenvt>r low T~rature At>rospace Soi I (l4,400 \IOCS (ICE) PredHlgn State le-ad George D•nc I Ii: Aerospace), co• Thermal I reatme-nt [quipnPnt ,y) ( under RCIIA J0:5-l9:5· 1S06 (09/l4/90) Manufacturer Corrective Act Ion ns no-1~06 See also Vacuun Authority) (11traction
lr.jic&lf''> that a t,. atabi Ii ty c;tudy has bet>n COffflletffl.
'J-9 Cont.aclc; tistffi air rrA regional staff u-llt>~S otherwise irdica1ed.
/
l
3.11 • EXHIBIT 4 -BOILING POINTS O!LECTED COMPOUNDS
Chcmic;al Name
BeClz
Unuuum and Compounds
Iron
FeC12 FeC!3 Nickel
Chromium
CrOzClz
Copper
CuCI
CuC1 2 Chromium, hexavalen1
Manganese and Compounds
Lead (Pb)
PbC!2 Barium
Bao
Zinc and Compounds
ZnO
ZnCfz.
Cadmium
CdO
CdC12 SnC12 Arsenic and Compounds
AS 2O1 2.3, 7 ,8-dioxin
Mercury
HgCL
Phenanthrene
Sc02 Pentachlorophenol
Fluorene
Lindane
Polychlorinated biphenyls
Pyrene
DDT
Methanol
Styrene
Xylene
Ethyl benzene
Chlorobenzene
Tetrachloroethane
1, l ,2,2-tetrachloroethane
Tetrachloroethene
I, 1,2-trichloroethane
Toluene
Boilia11 Poial
'F f'Cl
7 .052
6,904
4,982
1,238
599
4,949
4,842
243
4,653
2,49 I
1.8 I 9
4,500
3,564
3,171
1,742
2,084
3,632
1,665
3,272
1,350
1,409
1.652-1,832
1,760
I, 153
I. 135
379
932-1.500
675
575
644
603
588
559
550
512
500
500
360
293
280
277
270
3-10
264-295
295
250
235
232
(3,900)
(3.8 I 8)
(2. 750)
(670)
(3 I 5)
(2.i32)
(2,672)
( I I 7)
(2,567)
(1,366)
(993)
(2,482)
(1,962)
(1,744)
(950)
(I, 140)
(2,000)
(907)
( 1800)
(732)
(765)
(900-1,000)
(960)
(623)
(6 I 3)
( 193)
(500-800)
(357)
(302)
(340)
( 3 I 7)
(309)
(293)
(288)
(267-.)
(260)
(260)
( I 82)
( 145)
(138)
( I 36)
(132)
(129-146)
( 146)
( I 21)
( II 3)
(111)
3.11 EX.T ◄·BOILING POINTS OF SELE,COMPOUNDS -(Cootinutd)
Chcmkll Name
Trichloroethylene (TCE)
I ,2-dichloroethane
Methyl ethyl ketone
Benzene
Carbon tetrachloride
1,1,l •trichloroethane
Chloroform
Cis-1,2-dichloroethylene
I, I •dichloroethane
Acetone
1,2. trans-dichloroethylene
Methylene chloride
I, I •dichloroethene
Cyanides (for HCN)
Naphthalene
Vinyl chloride
Boilin& Point
'f CC}
189 (87)
I 83 (84)
176 (80)
176 (80)
I 7 I (77)
165· (74)
142 (61)
140 (60)
I 35 (57)
133 (56)
118 (48)
106 (41)
90 (32)
80 (27)
70 (21)
7 (-13.9)
Boilinc point i, for the pUN c:hem.ic:al itHlf ~d may not r,!lec:t that for tru vanou, c:ompounda Sublimata.
Decompoea.
3-11
3.8
•
EXHIBIT 5 -BOILI'.'IG POINTS FO.UBSTANCES OCCURRING \!OST
FREQUENTLY AT NPL SITES'
Chemical Name
BeCI,
Uranium and Compounds
Iron
FeCI,
FeCI,
Nickel
Chromium
CrO,Cl,
Copper
CuCI
CuCI,
Boiling
Point 'FCC}
7,052 (3,900)
6,904'(3,818)
4,982' (2,750)
1,238 (670)
599 (315)
4,949'(2,732)
4,842' (2,672)
243' (117)
4,653' (2,567)
2,491 (1,366)
Chromium, hexavalent
Manganese and Compounds
Lead (Pb)
1,819' (993)
4,500 (2,482)
3,564' (1,962)
3,171'(1,744)
PbCl,
Barium
BaO
Zinc and Compounds
ZnO,
ZnCI,
1,742 (950)
2,084 (1,140)
3,632 (2,000)
1,665" '907)
3,272 ( 1800)
1,350 (732)
1,409'(765) Cadmium
CdO
CdCI,
SnCI,
1,652-1,832 (900-1,000)
Arsenic and Compounds
AS,0,
2,3, 7 ,8-dioxin
Mercury
HgCL
Phenanthrene
Seo,
Pentachlorophenol
Fluorene
Lindane
Polychlorinated biphenyls
Pyrene
DDT
Methanol
Styrene
Xylene
Ethylbenzene
Chlorobenzene
Tetrachloroethane
l, l ,2,2-tetrachloroethane
Tetrachloroethene
I, 1,2-trichloroethane
Toluene
1,760 (960)
1,153 (623)
1,135'(613)
379 (193)
932-1,500' (500-800)
675 (357)
575 (302)
644 (340)
603(317)
588 (309)
559 (293)
550 (288)
512+ (267+)
500 (260)
500 (260)
360 (182)
293 (145)
280 (138)
277 (136)
270 (132)
264-295 (129-146)
295 (146)
250 (121)
235(113)
232 ( 111)
Chemical Name
Trichloroethylene (TCE)
1,2-dichloroethane
Methyl ethyl ketone
Benzene
Carbon tetrachloride
l, l, l -trichloroethane
Chloroform
Cis-1,2-dichloroethylene
I, 1-dichloroethane
Acetone
1,2-trans-dichloroethylene
Methylene chloride
1, 1-dichloroethene
Cyanides (for HCN)
Naphthalene
Vinyl chloride
Actual pa.rtitionin1 or 1ub.ta.nc:u may depend on matrix condition,
Boiling
Point 'F f'C}
189(87)
183 i g.: l
176 (SOl
1 76 I SOI
17 I ( 77 l
165 (7-!)
14: (61'
140 (60)
135(57)
133(56)
118 ( 48)
106 (4 I)
90 (3:)
80 (27)
70 (21)
57(-139)
.. Thu li1t ii a frequency of 1ubtt:anc:• documented durinc HRS ICON: preparation, not a complete inventory of
,ubtta.nca at all aita . • Boilinc point ii for the pure chemical itM:lf and may not reflect that for the Yarioua compound,.
Sublimata.
DecompoMI.
44 Preliminary Draft -April, 1991
• Unlled S1alas.
Enwonmallllll "P"',otadloi_,.....,,
Ar,,,tw:y
Superfund
Offlc:e ·••11e11cy and
Remedie' Ra i C 11111
Wasl'll11gto11, DC 20460
EPA/540/2-91/008
Olllce of.
Rua 111'Ch and 01,t, alopment
CII idl • lidl, OH 45268
May 1991
&EPA Engineering Bulletin
Thermal Desorption Treatment
Purpose
Section 121 (b) of the Comprehensive Environmental Re-
sponse, Compensation, and Liability Act (CERCLA) mandates
· the Environmental Protection Agency (EPA) to select remedies
that "utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the maxi-
mum extent practicable" and to prefer remedial actions in
which treatment "permanently and significantly reduces the
volume, toxicity, or mobility of hazardous substances, pollut-
ants and contaminants as a principal element." The Engi-
neering Bulletins are a series of documents that summarize
the latest information available on selected treatment and site
remediation technologies and related issues. They provide
summaries of and references·for the latest information to help
remedial project managers, on-scene coordinators, contrac-
tors, and other site cleanup managers understand the type of
data and site characteristics needed to evaluate a technology
for potential applicability .to their Superfund or other hazard-
ous waste site. Those documents that describe individual
treatment technologies focus on remedial investigation scoping
needs. Addenda will be issued periodically to update the
original bulletins.
Abstract
Thermal desorption is an ex situ means to physically
separate volatile and some semivolatile contaminants from
soil, sediments, sludges, and filter cakes. For wastes contain-
ing up to 1 0% organics or less, thermal desorption can be
used alone for site remediation. It also may find applications
in conjunction with other technologies or be appropriate to
specific operable units at a site.
Site-specific treatability studies may be necessary to
document the applicability and performance of a thermal
desorption system. The EPA contact indicated at the end of
this bulletin can assist in the definition of other contacts and
sources of information necessary for such treatability studies.
Thermal desorption is applicable to organic wastes and
generally Is not used for treating metals and other inorganics.
Depending on the specific thermal desorption vendor se-
lected, the technology heats contaminated media between
200-1000°F, driving off water and volatile contaminants.
• [reference number, page number)
...
Offgases may be burned in an aherburner, condensed to
reduce the volume to be disposed, or captured by carbon
adsorption beds.
Commercial-scale units exist and are in operation. Ther-
mal desorption has been selected at approximately fourteen
Superfund sites [1]• [2]. Three Superfund Innovative Technol-
ogy Evaluation demonstrations are planned for the next year.
The final determination of the lowest cost alternative will
be more site-specific than process equipment dominated.
This bulletin provides information on the technology applica-
. bility, limitations, the types of residuals produced, the latest
performance data, site requirements, the status of the tech-
nology, and sources for further information.
Technology Applicability
Thermal desorption has been proven effective in treating
contaminated soils, sludges, and various filter cakes. Chemi-
cal contaminants for which bench-scale through full-scale
treatment data exist include primarily volatile organic com-
pounds (VOCs), semivolatiles, and even higher boiling point
compounds, such as polychlorinated biphenyls (PCBs)
(3](4](5](6]. The technology is not effective in separating
inorganics from the contaminated medium. Volatile metals,
however, may be removed by higher temperature thermal
desorption systems.
Some metals may be volatilized by the thermal desorp-
tion process as the contaminated medium is heated. The
presence of chlorine in the waste can also significantly affect
the volatilization of some metals, such as lead. Normally the
temperature of the medium achieved by the process does not
oxidize the metals present in the contaminated medium [7, p.
BS].
The process is applicable for the separation of organics
from refinery wastes, coal tar wastes, wood-treating wastes,
creosote-contaminated soils, hydrocarbon-contaminated soils,
mixed (radioactive and hazardous) wastes, synthetic rubber
processing wastes, and paint wastes (8, p. 2](4](9].
Performance data presented in this bulletin should not be
considered directly applicable to other Superfund sites. A
number of variables, such as the specific mix and distribution
@ Printed on Recycled Paper
I:
-~ • 0 E' 0
-~ • 0 E' 0 .s
~ ·.: V 0 • ..
■ ,,
□
Arable 1
RCRA d191's for Wastes Treated
by Thermal Desorption
Wood Treating Wastes KOOl
Dissolved Air Flotation (OAF) .Float K048
Slop Oil Emulsion Solids K049
Heat E;o;changer Bundles Cleaning Sludge KOSO
American Petroleum Institute (API)
Separator Sludge K051
Tank Botto"1s (leaded) K052
Table 2
Effectiveness of Thermal Desorption on
General Contaminant Groups for Soll,
Sludge, Sediments, and Filter Cakes
Effectiveneu
Sedl-
Contaminant Groups Soil Sludge mentl
Halogenated volatiles • • •
Halogenated semivolatiles • • •
Nonhalogenated volatiles • • •
Nonhalogenated semivolatiles • • •
PCBs • • • Pesticides • • •
Dioxins/Furans • • •
Organic cyanides • • • Organic corrosives 0 0 0
Volatile metals • • •
Nonvolatile metals 0 0 0
Asbestos 0 0 0
Radioactive materials 0 ·O 0
Inorganic corrosives 0 0 0
Inorganic cyanides 0 0 0
Oxidizers 0 0 0
Reducers 0 0 0
Filter
Cakes
• • • • • • • •
0 •
0
•O
0
0
0
0
0
Demonstrated Effectiveness: Successful treatability test at some scale
completed
Potential Effectiveness: Expert opinion that technology will work
No Expected Effectiveness: Expert opinion that technology will not
worl<
of contaminants; affect system performance. A thorough
· characterization of the site and a well-designed and con-
ducted treatability study are highly recommended.
Table 1 lists the codes for the specific Resource Conse~a-
tion and Recovery Act (RCRA) wastes that have been treated
by this technology (8, p. 2](4](9]. The indicated codes were
derived from vendor data where the objective was to deter-
mine thermal desorption effectiveness for these specific in-
dustrial wastes. The effectiveness of thermal desorption on
general contaminant groups for various matrices ·is shown in
Table 2. Examples of constituents within contaminant groups
are provided in "Technology Screening Guide For Treatment
2
of.LA Soils and Sludges" (7, p. 1 OJ. This table is based on
th rent available information or professional judgment
where no information was available. The proven effectiveness
of the technology for a particular site or waste does not ensure
that it will be effective at all sites or that the treatment
efficiencies achieved will be acceptable at other sites. For the
ratings used for this table, demonstrated effectiveness means
that, at some scale, treatability was tested to sh0w the tech-
nology was effective for that particular contaminant and me-
dium. The ratings of potential effectiveness or no expected
effectiveness are both based upon expert judgment. Where
potential effectiveness is indicated, the technology is believed
capable of successfully treating the contaminant group in a
particular medium. When the technology is not applicable or
will probably not work for a particular combination of con-
taminant group and medium, a no expected effectiveness
rating is given. Another source of general observations and
average removal efficiencies for different treatability groups is
contained in the Superfund Land Disposal Restrictions (LDR)
Guide #6A, "Obtaining a Soil and Debris Treatability Variance
for Remedial Actions," (OSWER Directive 9347.3-06fS, Sep-
tember 1990) (1 OJ and Superfund LDR Guide #68, "Obtain-
ing a Soil and Debris Treatability Variance for Removal Ac-
tions," (OSWER Directive 9347.3-06BfS, September 1990)
[11 J.
Limitations
The primary technical factor affecting thermal desorption
performance is the maximum bed temperature achieved. Since
the basis of the process is physical removal from the medium
by volatilization, bed temperature directly determines which
organics will be removed.
The contaminated medium must contain at least 20 per-
cent solids to facilitate placement of the waste material into
the desorption equipment (3, p. 9). Some systems specify a
minimum of 30 percent solids (12, p. 6].
As the medium is heated and passes through the kiln or
desorber, energy is lost in heating moisture contained in the
contaminated soil. A very high moisture content can result in
low contaminant volatilization or a need to recycle the soil
through the desorber. High moisture content, therefore,
causes increased treatment costs.
Material handling of soils that are tightly aggregated or
largely clay, or that contain rock fragments or particles greater
than 1-l .5 inches can result in poor processing performance
due to caking. Also, if a high fraction of fine silt or clay exists
in the matrix, fugitive dusts will be generated (7, p. 83] and a
greater dust loading will be placed on the downstream air
pollution control equipment (12, p. 6].
The treated medium will typically contain less than 1
percent moisture. Dust can easily form in the transfer of the
tr"eated medium from the desorption unit, but can be mitigated
by water sprays. Normally, clean water from air pollution
control devices can be used for this purpose.
Although volatile organics are the primary target of the
thermal desorption technology, the total organic loading is
limited by some systems to up to 10 percent or less [13, p. II-
Engineering Bulletin: Thermal Desorption Treatment
30]. As in most systeAat use a reactor or other eq~ipment
to process wastes, a ,,am exhibiting a very high pH (greater
than 11) or very low pH (less than 5) may corrode the system
components (7, p. 85].
There is evidence with some system configurations that polymers may foul and/or plug heat transfer surfaces (3, p. 9]. Laboratory/field tests of thermal desorption systems have documented the deposition of insoluble brown tars (presum-
ably phenolic tars) on internal system components (14, p.
76].
High concentrations of inorganic constituents and/or metals will likely not be effectively treated by thermal desorp-
tion. The maximum bed temperature and the presence of chlorine can result in volatilization of some inorganic constitu-ents in the waste, however.
Technology Description
Thermal desorption is any of a number of processes that
use'either indirect or direct heat exchange to vaporize organic contaminants from soil or sludge. Air, combustion gas, or inert gas is used as the transfer medium for the vaporized components. Thermal desorption systems are physical sepa-ration processes and are not designed to provide high levels
of organic destruction, although the higher temperatures of some systems will result in localized oxidation and/or pyroly-sis. Thermal desorption is not incineration, since the destruc-tion of organic contaminants is not the desired result. The bed temperatures achieved and residence times designed
into thermal desorption systems will volatilize selected con-taminants, but typically not oxidize or destroy them. System performance is typically measured by comparison of untreated soil/sludge contaminant levels with those of the processed soil/sludge. Soil/sludge is typically heated to 200 -1000° F, based on the thermal desorption system selected.
Figure 1 is a general schematic of the thermal desorption process·.
Aste material handling (1) requires excavation of the coZ:inated soil or sludge or delivery of filter cake to the
system. Typically, large objects greater than 1 .5 inches are screened from the medium and rejected. The medium is then delivered by gravity to the desorber inlet or conveyed by augers to a feed hopper [8, p. 1 ].
Significant system variation exists in the desorption step (2). The dryer can be an indirectly fired rotary asphalt kiln, a single (or set of) internally heated screw auger(s), or a series of externally heated distillation chambers. The latter process
uses annular augers to move the medium from one volatiliza-
tion zone to the next. Additionally, testing and demonstration data exist for a fluidized-bed desorption system (12].
The waste is intimately contacted with a heat transfer surface, and highly volatile components (including water) are driven off. An inert gas, such as nitrogen, may be injected in a countercurrent sweep stream to prevent contaminant com-bustion and to vaporize and remove the contaminants [8, p. 1](4]. Other systems simply direct the hot gas stream from the desorption unit (3, p. 5](5].
The actual bed temperature and residence time are the
primary factors affecting performance in thermal desorption. These parameters are controlled in tfie desorption unit by using a series of increasing temperature zones [8, p. 1 ], mul-tiple passes of the medium through the desorber where the operating temperature is sequentially increased, separate
compartments where the he~t transfer fluid temperature is higher, or sequential processing into higher temperature zones (15](16]. Heat transfer fluids used to date include hot com-bustion gases, hot oil, steam, and molten salts.
Offgas from desorption is typically processed (3) to re-move particulates. Volatiles in the offgas may be burned in an afterburner, collected on activated carbon, or recovered in condensation equipment. The selection of the gas treatment
system will depend on the concentrations of the contaminants,
cleanup standards, and the economics of the offgas treat-ment system(s) employed.
Figure 1
Schematic Diagram ol Thermal DesorpHon
Excavate
Material
Handling
(1)
Deso<ption
(2)
Oversized Rejects
Engineering Bulletin: Thermal Desorption Treatment
Gas Treatment
System
(3)
r --
Clean Offgas
Spem
Carbon
Concemrated Contaminants
I '--II► Water
'
Treated
Medium
3
• :x;ess Residuals
Operation of thermal desorption systems typically cre-
s up to six process residual streams: treated medium,
!rsized medium reiects, condensed contaminants and wa-
, particulate control system dust, clean offgas, and spent
·ban (if used). Treated medium, debris, and oversized
ects may be suitable for return onsite.
Condensed water may be used as a dust suppressant for
e treated medium. Scrubber purge water can be purified
.d returned to the site wastewater treatment facility (if
ailable), disposed to the sewer [3, p. 8] [8, p. 2] [4, p. 2], or
ed for rehumidification ari"d cooling of the hot, dusty me-
a. Concentrated, condensed organic contaminants are
intainerized for further treatment or recovery.
Dust collected from particulate control devices may be
)mbined with the treated medium or, depending on analy-
!S for carryover contamination, recycled through the des-
rption unit.
Clean off gas is released to the atmosphere. lf used, spent
arbon may be recycled by the original supplier or other such
1rocessor.
me Requirements
Thermal desorption systems are transported typically on
;pecifically adapted flatbed semitrailers. Since most systems
.:onsist of three components (desorber, particulate control,
rnd gas treatment), space requirements on site are typically
less than 50 feet by 150 feet, exclusive of materials handling
and decontamination areas.
Standard 440V, three-phase electrical service is needed.
Water must be available at the site. The quantity of water
needed is vendor and site specific.
Treatment of contaminated soils or other waste materials
require that a site safety plan be developed to provide for
personnel protection and special handling measures. Storage
should be provided to hold the process product streams until
tt1ey have been tested to determine their acceptability for
disposal or release. Depending upon the site, a method to
store waste that has been prepared for treatment may be
necessary. Storage capacity will depend on waste volume.
I Matrix
Clay
Silty Clay
Clay
Sandy
Clay
4
Table3
PCB Contamlnatlld Soils
PIiot X "11IAX"' [ 4]
Fttd Product
(ppm) (ppm)
5,000 24
2,800 19
1,600 4.8
1,480 8.7
630 17
Removal
(%)
99.3
99.5
99.7
99.l
97.3
Onsite analytical eq.ent capable of determining site-
specific organic compounds for performance assessment make
the operation more efficient and provide better information
for process control.
Performance Data
Several thermal desorption vendors report performance
data for their respective systems ranging from laboratory
treatability studies to full-scale operation at designated
Superfund sites [1 7][9][ 18]. The quality of this information
has not been determined. These data are included as a
general guideline to the performance of thermal desorption
equipment, and may not be directly transferrable to a specific
Superfund site. Good site characterization and treatability
studies are essential in further refining and screening the
ther.mal desorption technology.
Chem Waste Management's (CWM's) x•TRAX'" System
has been tested at laboratory and pilot scale. Pilot tests were
performed at CWM's Kettleman Hills facility in California.
Twenty tons of PCB-and organic-contaminated soils were
processed through the S TPD pilot system. Tables 3 and 4
present the results of PCB separation from soil and, total
hydrocarbon emissions from the system, respectively (4}.
During a non-Superfund project for the Department of
Defense, thermal desorption was used in a full-scale demon-
stration at the Tinker Air Force Base in Oklahoma. The success
of this project led to the patenting of the process by Weston
Services, Inc. Since then, Weston has applied its low-tem-
perature thermal treatment (LT3) system to various contami-
nated soils at bench-scale through full-scale projects [ 19].
Table 5 presents a synopsis of system and performance data
for a full-scale treatment of soil contaminated with No. 2 fuel
oil and gasoline at a site in Illinois.
Canonie Environmental has extensive performance data
for its Low Temperature Thermal Aeration (LTTASM) system at
full-scale operation (15-20 cu. yds. per hour). The LTTA'M has
been applied at the McKin (Maine), Ottati and Goss (New
Hampshire) and Cannon Engineering Corp. (Massachusetts)
Superfund sites. Additionally, the LTTA'M has been used at
the privately-funded site in South Kearney (New Jersey). Table
Table4
PIiot x·Tl!AX™
TSCA Testing -Vent Emissions [4]
Total Hydrocarbons
(ppm-V)
B,for, Afttr Rtmoval voe
Carbon Carbon I (%) (lbs/day)
1,320 57 95.6 0.02
1,031 72 93.0 0.03
530 35 93.3 0.01
2,950 170 94.2 0.07
2,100 180 91.4 0.08
PCB•
(mg!m 1)
-::0.00056
<0.00055
<0.00051
<0.00058
<0.00052
•Note: OSHA permits 0.50 mg/m' PCB (1254) for 8-hr
exposure.
Engineering Bulletin: Thermal Desorption Treatment
6 presents a summary&nonie LTTA'" data [5]. The Can-non Engineering (Mass., which was not included in Table 6, successfully treated a total of 11,330 tons of soil, containing approximately 1803 lbs. of voe [20].
T.D.J. Services, Inc. has demonstrated its HT-5 Thermal Distillation Process at pilot-and full-scale for a variety of RCRA-listed and other wastes that were prepared to simulate Ameri-can Petroleum Institute (API) refinery sludge (8). The com-pany has conducted pilot-and full-scale testing with the API
Tobie 5
Full-Scale Performance Results
for the LT' System [ 19]
Soil Range Treated Range
Contaminant (ppb) (ppb)
Benzene 1000 5.2
Toluene 24000 5.2
Xylene 110000 <1.0
Ethyl benzene 20000 4.8
Napthalene 4900 <330
C arcinogen_ic
Priority PNAs <6000 <330-590
Non-carcinogenic
Pf"iority PNAs 890-6000 <330-450
Tobie 7
Range of
Removal
Efficiency
99.5
99.9
>99.9
99.9
>99.3
<90.2-94.5
<62.9-94.5
ReTec Treatment Results-Refinery
Vacuum Filter Coke (Al [3]
Original Treated Removal Sample Sample Efficiency Compound (ppm) (ppm) (%)
Naphthalene <0.1 <0.1
Acenaphthylene <0.1 <0.1
Acenaphthene <0.1 <0.1
Fluorene 10.49 <0.1 >98.9
Phenanthrene 46.50 <0.1 >99.3
Anthracene 9.80 <0.1 >96.6
Fluoranthrene 73.94 <0.1 >99.8
Pyrene 158.37 <0.1 >99.9
l}eAZO(b )anthracene 56.33 1.43 97.5
Chrysene 64.71 <0.1 >99.9
Behzo(b )fluoranthene 105.06 2.17 97.9
Benzo(k)fluoranthene 225.37 3.64 98.4
Benzo(a)pyrene 174.58 1.89 98.9
Dibenz( ab )antracene 477.44 10.25 97.8
8enzo(ghi)perylene 163.53 5.09 96.6
lndeno(l 23-cd)pyrene 122.27 4.16 96.6
Treatment Temperature: 450°F
slu. demonstrate the system's ability to meet LJnd 8Jn Disposal requirements for K048 through K052 wastes. Inde-pendent evaluation by Law Environmental coniirms that the requirements were met, except for TCLP leve!s of nickel, which were blamed on a need to "wear-in" the HT-5 system [21, p. ii).
Remediation Technologies, Inc. (ReTec) has performed numerous tests on RCRA-listed petroleum refinery wastes. Table 7 presents results from treatment of refinery vacuum
Tobie 6
Summary Results of the LTTA'"
Full-Scale Cleanup Tests [5)
Contom-Soil Treated Site Processed inont (ppm) (ppm)
S. Kearney 16000 tom voes 177.0 (avg.) 0.87 (avg.) PAHs 35.31 (,wg.) 10.1 (<1vg.J
McKin >9500 cu yds voes ND-3310 ND-0.04 2000 cu yds PAHs <10
OttJli & 4500 cu yds Goss voes 1500 (avg.) <0.2 (avg.)
Tobie 8
ReTec Treatment Results-Creosote
Contaminated Cloy [3]
Original Treated Removal
Sample Sample Efficiency Compound (ppm) (ppm) (%)
Naphthalene 1321 <0.1 >99.9
Acenaphthylene <0.1 <0.1
Acenaphthene 293 <0.1 >99.96
Fluorene 297 <0.1 >99.96
Phenanthrene 409 1.6 99.6
Anthracene 113 <0.1 >99.7
Fluoranthrene 553 1.5 99.7
Pyrene 495 2.0 99.6
Benzo(b)anthracene 59 <0.1 >99.99
Chrysene 46 <0.1 >99.8
Benzo(b)fluoranthene 14 2.5 82.3
Benzo(k)fluoranthene 14 <0.1 >99.8
Benzo(a)pyrene 15 <0.1 >99.9
Dibenzo(ab )anthracene <0.1 <0.1
Benzo(ghi)perylene 7 <0.1 >99.4
lndeno(l 23-cd)pyrene 3 <0.1 >99.3
Treatment Temperature: 500°F
Engineering Bulletin: Thermal Desorption Treatment 5
i
1
Table9 -
ReTec Treatment Resu~oal Tar
Contaminated Solis [3]
Oriyinal Treated
Samp~ Sample
Compound (ppm) (ppm)
Benzene 1.7 <0.1
Toluene 2.3 <0.1
Ethyl benzene 1.6 <0.1
Xylenes 6.3 <0.3
Naphthalene 367 <1.7
Fluorene 114 <0.2
Phenanthrene 223 18
Anthracene 112 7.0
Fluoranthrene 214 15
Pyrene 110 11
Benzo(b )anthracene 56 <1.4
Chrysene 58 3.7
Benzo(b )fluoranthene 45 <1.4
Benzo(k)fluoranthene 35 <2.1
Benzo(a)pyrene 47 <0.9
Benzo(ghi)perylene 24 <1.1
lndeno(l 23-cd)pyrene 27 <6.2
Removal
Efficiency
(%)
>94
>95
>93
>95
>99
>99
91.9
93.8
93.0
90.0
>97
93.6
>97
>94
>98
>95
>77
·1 Treatment Temperature: 450°F
filter cake. Tests with creosote-contaminated clay and coal
tar-contaminated soils showed significant removal efficiencies
(Tables 8 and 9). All data were obtained through use of
ReTec's 100 lb/h pilot scale unit processing actual industrial
process wastes [3 ].
Recycling Sciences International, Inc. (formerly American
Toxic Disposal, Inc.) has tested its Desorption and Vaporiza-
tion Extraction System (DAVES), formerly called the Vaporiza-
tion Extraction System (YES), at Waukegan Harbor, Illinois.
The pilot-scale test demonstrated PCB removal from material
containing up to 250 parts per million (ppm) to levels less
than 2 ppm [l 2].
RCRA LDRs that require treatment of wastes to best dem-
onstrated available technology (BOAT) levels prior to land
disposal may sometimes be determined to be applicable or
relevant and appropriate requirements for CERCLA response
acti6ns. Thermal desorption can produce a treated waste
that meets treatment levels set by BOAT but may not reach
these treatrllent levels in all cases. The ability to meet re-
quired treatment levels is dependent upon the specific waste
constituents and the waste matrix. In cases where thermal
des0rption does not meet these levels, it still may, in certain
situations, be selected for use at the site if a treatability
variance establishing-alternative treatment levels is obtained.
Treatability variances are justified for handling complex soil
and debris matrices. The following guides describe when and
how to seek a treatability variance for soil and debris:
Superfund LDR Guide #6A, "Obtaining a Soil and Debris
Treatability Variance for Remedial Actions" (OSWER Directive
6
9347.3-06FS, Sept., 1990) [l OJ, and Superfund LDR Guide
#68, "Obtaining a Soil and Debris Treatability Variance for
Removal Actions" (OSWER Directive 9347.3-06BFS, Septem-
ber 1990) [11 ]. Another approach could be to use other
treatment techniques in series with thermal desorption to
obtain desired treatment levels.
Technology Status
Significant theoretical research is ongoing [221(23], as
well as direct demonstration of thermal desorption through
both treatability testing and full-scale cleanups.
A successful pilot-scale demonstration of Japanese soils
"roasting" was conducted in 1980 for the recovery of mercury
from highly contaminated (up to 15.6 percent) soils at a plant
site in Tokyo. The high concentration of mercury made
recovery and refinement to commercial grade (less than 99. 99
percent purity) economically feasible [24].
In this country, thermal desorption technologies are the
selected remedies for one or more operable units at fourteen
Superfund sites. Table 10 lists each site's location, primary
contaminants, and present status [l ][2].
Most of the hardware components of thermal desorption
are available off the shelf and represent no significant problem
of availability. The engineering and configuration of the
systems are similarly refined, such that once a system is de-
signed full-scale, little or no prototyping or redesign is required.
On-line availability of the full-scale systems described in
this bulletin is not documented. However, since the ex situ
system can be operated in batch mode, it is expected that
component failure can be identified and spare components
fitted quickly for minimal downtime.
Several vendors have documented processing costs per
ton of feed processed. The overall range varies from SB0 to
$350 per ton processed [61[4, p. 121[5][3, p. 9]. Caution is
recommended in using costs out of context because the base
year of the estimates vary. Costs also are highly variable due
to the quantity of waste to be processed, term of the reme-
diation contract, moisture conterit, organic constituency of
the contaminated medium, and cleanup standards to be
achieved. Similarly, cost estimates should include such items
as preparation of Work Plans, permitting, excavation, pro-
cessing itself, QA/QC verification of treatment performance,
and reporting of data.
EPA Contact
Technology-specific questions regarding thermal desorp-
tion may be directed to:
Michael Gruenfeld
U.S. Environmental Protection Agency
Risk Reduction Engineering Laboratory
Releases Control Branch
2890 Woodbridge Ave.
Bldg. 10 (MS-104)
Edison, NJ 08837
FTS 340-6625 or [phone]
Engineering Bulletin: Thermal Desorption Treatment
.1/
~ '
'I
• TablelO.
Supel1und Sites Specl!ying Thermal Desorption as the Remedial Action
Site
Cannon Engineering
(Bridgewater Site)
McKin
Ottati & Goss
I Wide Beach
Metaltec'/ Aerosysterns
1 Caldwell Trucking
1 Outboard Marine/
Waukegan Harbor
Reich Farms
Re-Solve
Waldick Aerospace
Devices
Wamchem
1 Fulton Terminals
Stauffer Chemical
Stauffer Chemical
Acknowledgements
Location
Bridgewater, MA (1)
McKin, ME (l)
New Hampshire (1)
Brandt, NY (2)
Franklin Borough, NJ (2)
Fairfield, NJ (2)
Waukegan Harbor, ll (5)
Dover Township, NJ (02)
North Dartmouth, MA (1)
New Jersey (2)
Burton, SC (4)
Fulton, NY (2)
Cold Creek, AL (4)
Le Moyne, AL ( 4)
This bulletin was prepared for the U.S. Environmental
·Protection Agency, Office of Research and Development
(ORD), Risk Reduction Engineering Laboratory (RREL), Cin-
cinnati, Ohio, by Science Applications International Corpora-
tion ·(SAIC) under contract no. 68-CB-0062. Mr. Eugene
Harris served as the EPA Technical Project Monitor. Mr. Gary
Baker (SAIC) was the Work Assignment Manager and author
of this bulletin. The author is especially grateful to Mr. Don oberacker, Ms. Pat Lafornava, and Mr. Paul de Percin of EPA,
RREL, who have contributed significantly by serving as tech-
nical consultants during the development of this document.
Primary Contaminants
VOCs (Benzene, TCE &.
Vinyl Chloride)
voes (TCE, BTX)
voes (TCE; PCE; I, 2-DCA.
and Benzene)
PCBs
TCE and VOCs
VOCs (TCE, PCE, and TCA)
PCBs
VOCs and Semivolatiles
TCE and PCE
BTX and SVOCs
(Naphthalene)
voes (Xylene, Styrene, TCE,
Ethylbenzene, Toluene) and
some PAHs
voes and pesticides
voes and pesticides
Status
Project completed 1 0/90
Project completed 2/87
Project completed 9/89
ln design
• pilot study available 5/91
In design
remedial design comptete
• remediation starting Fall '91
In design
In design
• treatability studies complete
Pre-design
In design
• pilot study June/July ·91
In design
In design
• pilot study available 5/91
Pre-design
Pre-design
Pre-design
The following other Agency and contractor personnel
have contributed their time and comments by participating in
the expert review meetings and/or peer reviewing the docu-
ment:
Dr. James Cudahy
Mr. James Cummings
Dr. Steve Lanier
Ms. Evelyn Meagher-Hartzell
Mr. James Rawe
Ms. Tish Zimmerman
Focus Environme:ntal, Inc.
EPA-OERR
Energy and Environmental
Research Corp.
SAIC
SAIC
EPA-OERR
Engineering Bulletin: Thermal Desorption Treatment 7
1. Innovative Treatment Technologies: Semi-Annual Status.
Report, EPA/540/2-91 /001, U.S. Environmental Protec-
tion Agency, Technology Innovation Office, Jan. 1991.
2. Personal communications with various EPA Regional
Project Managers, April, 1991.
3. Abrishamian, Ramin. Thermal Treatment of Refinery
Sludges and Contaminated Soils. Presented at Ameri-
can Petroleum Institute, Orlando, Florida, 1990.
4. Swanstrom, C., and C. Palmer. x•TRAX"' Transportable
Thermal Separator for Organic Contaminated Solids.
Presented at Second Forum on Innovative Hazardous
Waste Treatment Technologies: Domestic and Interna-
tional, Philadelphia, Pennsylvania, 1990.
5. Canonie Environmental Services Corp, Low Temperature
Thermal Aeration (LTTNM) Marketing Brochures, circa
1990.
6. Nielson, R., and M. Cosmos. Low Temperature Thermal
Treatment (LT') of Volatile Organic Compounds from
Soil: A Technology Demonstrated. Presented at the
American Institute of Chemical Engineers Meeting,
Denver, Colorado, 1988.
7. Technology Screening Guide for Treatment of CERCLA
Soils and Sludges. EPA/540/2-88/004, U.S. Environmen-
tal Protection Agency, 1988.
8. T.O.1. Services, Marketing Brochures, circa 1990.
9. Cudahy, J., and W. Troxler. 1990. Thermal Remedia-
tion Industry Update. II. Presented at Air and Waste
Management Association Symposium on Treatment of
Contaminated Soils, Cincinnati, Ohio, 1990.
10. Superiund LDR Guide #6A: (2nd Edition) Obtaining a
Soil and Debris Treatability Variance for Remedial
Actions. Superiund Publication 9347.3-06FS, U.S.
Environmental Protection Agency, 1990.
11. Superiund LDR Guide #68: Obtaining a Soil and Debris
Treatability Variance for Removal Actions. Superiund
Publication 9347.3-068FS, U.S. Environmental Protec-
tion Agency, 1990.
12. Recycling Sciences International, Inc., DAVES Marketing
Brochures, circa 1990.
13. The Superfund Innovative Technology Evaluation
Program -Progress and Accomplishments Fiscal Year
1989, A Tliird Report to Congress, EPN540/5-90/001,
U.S. Environmental Protection Agency, 1990.
8
14. Superiund Treatability Clearinghouse Abstracts. EPA/
540/2-89/001, U.S. Environmental Protection Agency,
1989.
15. Soil Tech, Inc., AOSTRA -Taciuk Processor Marketing
Brochure, circa 1990.
16. Ritcey, R., and F. Schwartz. Anaerobic Pyrolysis of
Waste Solids and Sludges -The AOSTRA Taciuk Process
System. Presented at Environmental Hazards Confer-
ence and Exposition, Seattle, Washington, 1990.
17. The Superfund Innovative Technology Evaluation
Program: Technology Profiles. EPA/540/5-89/013, U.S.
Environmental Protection Agency, 1989.
18. Johnson, N., and M. Cosmos. Thermal Treatment
Technologies for Haz Waste Remediation. Pollution
Engineering, XXl(l l ): 66-85, 1989.
19. Weston Services, Inc, Project Summaries (no dat~).
20. Canonie Environmental Services Corporation, Draft
Remedial Action Report -Cannons Bridgewater
Superiund Site, February 1991.
21. Onsite Engineering Report for Evaluation of the HT-5
High Temperature Distillation System for Treatment of
Contaminated Soils -Treatability Test Results for a
Simulated K0S 1 API Separator Sludge, Vol 1: Executive
Summary, Law Environmental, 1990.
22. Lighty, J., et al. The Cleanup of Contaminated Soil by
Thermal Desorption. Presented at Second International
Conference on New Frontiers for Hazardous Waste
Management. EPA/600/9-87 /0181, U.S. Environmental
Protection Agency, 1987. pp. 29-34.
23. Fox, R., et al. Soil Decontamination by Low-Tempera-
ture Thermal Separation. Presented at the DOE Model
Conference, Oak Ridge, Tennessee, 1989.
24. lkeguchi, T., and S. Gotch. Thermal Treatment of
Contaminated Soll with Mercury. Presented at Demon-
stration of Remedial Action Technologies for Contami-
nated Land and Groundwater, NATO/CCMS Second
International Conference, Bilthoven, the Netherlands,
1988. pp. 290-301.
Engineering Bulletin: Thermal Desorption Treatment
This document was prepared by Roy F. Weslon, Inc., expressly for EPA. It shall not be released or disclosed, in whole or in part,
without the express written permission of EPA.
TABLE 4-1
Feasibility Study
Poner'sSeptic Tank Pits Site
Section: 4 ·
Revision: 1
Daie: April 1992
Page: 3of14
Potential Cleanup Levels For Soils
Potential Cleanup Levels
Mean Cone. Carcinogenic Non-Carcinogenic
Chemical mg/kg Ris.k Risk Hazard Index
(HI)'
Surface Soil {Area I Al
Benzene 0.73 1.96 X 10·5
Carcinogenic PAH2 5.13 4.65 x IO"'
Lead 722.51 64.5
Surface Soil (Area I DJ
Benzene 0.096 2.61 X 10-6
Lead 250 22.38
Zinc 2269. I 9 I 8.61
Surface Soil (Wetlands)
Carcinogenic PAIi 0.44 3.18 X IQ-6
Subsurface' Soil (Area IA)
Carcinogenic PAH 14.71 2.07 X 10-6
I: Non-carcinogenic metal cleanup level based on attainment of a Hazard Index of I.
2: Carcinogenic Polynuclear Aromatic Hydrocarbons.
3: Depths below 3 feet have been considered subsurface as in the Risk Assessment.
8:\P2\POTTERS\FS-SEC4.CWS
(mg/kg)
E-06 E-05 E-04
0.037 0.37 3.7
0.01 I 0.11 I.I
0.037 0.37 3.7
0.138 1.38 13.8
7.106 71.06 710.6
•
Hl=l
11.2
11.2
122 •
• Bftlf~~~·-. e5t1ick-os·u.ryt,1
• JUL 14 19 PY FOR YOUR
NFORMATIOl'il ■
United States Department of theS¥mffQ$1tr~-•
Ms. Darcy Duin
FISH .>u\JD WILDLIFE SERvlCE
Raleigh Field Office
Post Office Box :]3726
Raleigh, North Carolina 27636-3726
July 10, 1992
North Carolina Remedial Section
North Superfund Remedial 2ranch
U.S. Environmental Protection Agency
345 Courtland Street, N.E.
Atlanta, Georgia 20365
Dear Ms. Duin,
·---■
In response to your June 17, 1992 letter to Hr. James Lee of the Depari:ment of the Interior ( Departmeni:), the u. S. Fish and \'/ildlife Service ( Service I has reviewed the Draft Record of Decision (Draft ROD) for the Potters Septic Tank Service Pi ts Superfund Si i:e in Sandy Creek, Bruns;1ick Couni:y, North Cc.rolina. Comments in this letter are intended to assist your investigations, assessments, and the planning process being conduci:ed pursuani: to Section 104 ( a) of the Comprehensi'I<= Environmental Response, Compensation, and Liability Act of 1980, as amended (42 U.S.C. 9601 et seq.). These planning aid comments are being provided on a technical assistance basis only and do not represent any position that the Depart.~ent may adopt concerning possible injury to natural resources under the Department's trusteeship.
Service review evidenced three concerns in the Draft ROD, including the characterization of site sediments, the need to delineate site wetlands, and the lack of non-discharge alternatives for treated groundwater. These concerns, which we discussed via telephone on Monday of this week, are detailed in this letter.
The greatest sediment contamination will occur in depositional areas adjacent and down-gradient of the source. It appears from the information provided that depositional areas were not targeted in the evaluation and that areas known to have been impacted by oil and sludge releases from the Potters Site, particularly Rattlesnake Branch, were not sampled. Analysis of samples collected from the area nearest the current focus of soil remediation may not detect contaminants which have accumulated in sediments underlying depositional areas down-gradient from historic releases. Additional sampling in Rattlesnake Branch and its floodplain should be conducted.
Additionally, interpretation·of sediment chemistry data is hindered by a lack of information· on physical parameters of the collected samples, particularly particle size and total organic carbon (TOC) content. Sediments are heterogeneous, and factors such as particle size and TOC greatly influence contaminant accumulation. If physical parameters of the sediments previously collected are known, they should be presented.
A delineation of wetlands on-site is recommended to ensure adequate restoration of these areas after remediation. The Service understands that soil removal in the forested wetlands may not be necessary; however, figures 30 and 31 indicate that some portions of forested wetlands may require remediation. While the Draft ROD states that all disturbed areas will be
• •
"backfilled, graded, and planted with t.'1e ·,egetat.ion which most closely mimics that found in the area" (page 114), the ccntingency measures for soil removal state that e:,cavat.ed areas would be re•regei:at.ed ·,1ith a "perennial grass" (page 121). If site wetlands are disturbed, t.hey shculd be recontoured t.o original grade, to ensure an adequate hydrological regime for wetland-dependent veget.at.ion, and revegetated with the s['ecies t·JPical of the immediate surrcundings. The Department's October 5, 1989 Preliminary Nat.ural Resources Survey ( PNRS) , which is attached, previcusl1 ad·1ocated a wetland delineaticn for this site.
Alternatives i;iresented in the Draft ROD and e•raluated in detail in the Feasibilit1 Study should include evaluation of non-discharge alternati·1es for disposal of treated groundwater. The only di3Fosal option evaluated is surface water discharge to Chinnis Branch. There may be advantages to using re-infiltration of treated groundwater, such as contaminant dilution by re-infiltrating treated water up-gradient from t.he source area.
We encourage the U.S. Environmental Prote-::t.ion Agency to_ address these dat.a needs in the Remedial Design phase of site act.i·1ities so that remediation proceeds on an adequate information base with respect to biological resources and contaminants. Thank you for the op,;ortunity to review the Draft ROD. If you have any questions regarding Service comments on.the Potters Pits Septic Tank Service Site, please give me a call (919-856-4520).
Sincere»:
£ugs~~
Acting Supervisor
• •
United States Department of the Interior
OFFICE OF ENVIRONME:"<TAL PROJECT REVIEW
WASHINGTON, D.C. 20240
ER 89/336 ·
Mr. Matthew Robbins
Chief, Grants and Contract Support Unit
Environmental Protection Agency
345 Courtland Street
Atlanta, Georgia 30365
Dear :'vlr. Robbins:
OCT 5 1983
The Department of the Interior has conducted a preliminary natural resources survey
(PNRS) under !AG !11493374-0 for the Potter's Septic Tank Service Pits Site, Maco,
Brunswick County, North Carolina. A site inspection was made on June 20, 1989, and the
the draft RI/FS work plan was reviewed to mal<e this survey. This letter constitutes our
survey report.
Background
-The Potter's Septic Tank Service Pits Site includes three areas approximately 0.8 miles
west of the intersection of Highway 7 4/76 and NC 87 in Maco. Area I is located on a
site which has light industry present. Areas 2 and 3 are located in the Sandy Creeks
Subdivision, a residential community.
The general area is fiat and covered by sandy soils. The Potter site lies between Little
Green Swamp on the southwest and Chinnis Branch, which flows through the site, and
Rattlesnake Branch on the northeast. Surface drainage is to Chinnis and Rattlesnake
Branches, to Hood Creek and the Cape Fear River. A shallow unconfined aquifer extends
to about 15 feet below the surface at site 2; the water levels in the aquifer are about 4
to 5 feet below land surface. Below the shallow aquifer is a IS-feet thick clay confining.
unit, and below it is a deeper aquifer, about IO feet thick which is the supply aquifer for
most residences in the area.
The three sites were used from I 969 to 1976 for the disposal of septic and oil sludges,
wood preserving process wastes and other industrial wastes. Disposal was in unlined,
shallow impoundments with depths of 2 to 8 feet and/or the waste was applied directly to
the soils on-site.
In the emergency removal· in 1984, sludges and contaminated soils were removed from
area 2, and a determination was made that the shallow aquifer was contaminated with
volatile organics including benzene, toluene, ethylbenzene and xylenes. Recent data
indicate that the deep aquifer has now been contaminated. Contaminated ground water
will discharge to Chinnis and Rattlesnake Branches. Surface soils are contaminated with
benzene, toluene, xylenes, PAHs and various metals, incuding mercury and chromium.
Analysis for pesticides and PCBs have not been conducted.
•
-2 -
Department of the lnJ..erior Trust Resources
Migratory birds, trust resources of the Department, occur on and adjacent to the site. Anadromous fish, also trust resources, including hickorJ shad, alewife, and blueback herring may utilize Rattlesnake Branch. Also, American shad, striped bass, and short-nose sturgeon are present in the Cape Fear River located about 8 miles downstream from Chinnis Branch.
The following endangered species are present in Brunswick County and may occur on or in the vicinity of this site:
Bald eagle (Haliaeetus leucocephalus)
Red--<!ockaded woodpecker (Pico ides borealis)
Peregrine falcon (Falco peregrinus)
Wood stork (M cteria americana)
Short-nose sturgeon Acipenser brevirostrom)
Rough-leaved loosestrife (Lysimachia asoerulaefolia)
In addition, there are species which although not now listed or officially proposed for listing as endangered or threatened, are under status review. "Status Review" species are not legally protected under the Endangered Species Act (Act), and are not subject to any of its provisions, including Section 7, until they are formally proposed or listed as threatened or endangered. We are providing the following list of Brunswick County status review species for the purpose of advance notification. The listing of any of the status review species during the course of the site remediation may necessitate an endangered species survey on the site. These species may be listed in the future, at which time tby will be protected under the Act.
Bachman's sparrow (Aimophila aestivalis)
Carolina gopher frog (Rana aireola ta capitol
Rare skipper (Problema bulenta)
Sensitive joint vetch (Aeschynomene virginica)
Riverbank sand grass (Calamovilfa brevipilis)
Chapman's sedge (Carex chapmanii)
Henslow's sparrow (Ammodramus henslowiil
Harper's fringe-rush (Fi mb r ist y !is perpusillal
Sarvis holly (Ilex amelanchier)
Carolina lilaeopsis (Lilaeopsis carolinensis) ,
Loose watermilfoil (Myriophflum laxum)
Carolina grass-o f-parnassusP arnass1acaro linanal
Well's pixie-moss (P idanthera barbulata var. brevifolial
Sun-facing coneflower Rudbeckia helipsidis)
Carolina goldenrod (Solidago pulchra)
Spring-flowering goldenrod (Solidago vernal
Wireleaf droseed (S orobolus teretifolius)
Awned meadowbeauty Rhex1a aristosa)
Sea-beach pigweed (Amaranthus pumilusl
• •
-

3

-
There are no nation~parks, national wildlife refuges or lndian reservations in the immedi~te vicinity ctt the Potter's site.
Conclusion/Recommendations
Due to past contamination and probable continued release of contaminants via ground water discharge, we are not prepared to agree to a covenant not to sue for damages to natural resources under our trusteeship. However, we would be willing to reconsider this position after reviewing the proposed biological survey for Chinnis Branch, which is to include quantitative benthic sampling, quantitative fish sampling, and an ecological characterization of the adjacent wetlands and upland habitat and after reviewing additional contaminant data of the surface waters and sediment of Chinnis Branch collected during the RI phase.
We recommend that the cont~actors conducting the wetland characterization during the RI phase use the Federal Manual for Identifying and Delineating Jurisdictional Wetlands, jointly released by the EPA, Army Corps of Engineers, Fish and Wildlife Service and Soil Conservation Service in January 1989, instead of the three-parameter method proposed in the RI/FS Workplan. In addition, we sug-gest Area I should be investigated as part of the RI and include contaminant sampling of surface water and sediments in the unnamed branch and pond located north/northeast of the site.
H you have questions, our Departmental contact for this_site is James H. Lee, Regional Environmental Officer in Atlanta. He can be reached at [phone].
Sincerely,
, . , , / -d /.(.Lf.,,;,,, ~-/, 1'-"-U,<ft<..
/ I
;f athan P. Deason, Director
nvironmental Project Review
• •
State of North Carolina
Department of Environment, Health, and Natural Resources
Division of Solid Waste Management
P.O. Box 27687 · Raleigh, North Carolina 27611-7687
James G. Marlin, Governor
William W. Cobey, Jr., Secretary
Ms. Darcy Duin
Remedial Project Manager
US EPA Region IV
345 Courtland Street, NE
Atlanta, GA 30365
6 July 1992
RE: Comments on the Draft Record of Decision
Potter's Septic Tank Service Pits NPL Site
Maco, Brunswick County
Dear Ms. Duin:
Revisions made
24 July 1992
and forwarded
lo the US EPA
Region IV
William L. Meyer
Director
We have reviewed the Draft Record of Decision for the above site received on 17 June 1992. Since the
draft we received was not a complete copy and since we have not yet receive(\ a response to our comments on
the Remedial Investigation Addendum, Draft Feasibility Study, and the Propo'sed Plan ( comments attached for
your reference), we are unable to provide a complete set of comments on the Draft Record of Decision at this
time. We plan to provide additional comments when we receive a complete copy of the Draft Record of
Decision. The following are our comments at this time:
(l) Additional comments on the Baseline Risk Assessment have been provided by the North
Carolina Environmental EpidemiolQ6')' Section (attached).
(2) Please provide the Responsiveness Summary referenced on page 15 of the ROD.
(3) A greater volume of soil may very likely require treatment than is proposed in the ROD. The
ROD should not limit the amount of soil requiring treatment.
( 4) Treatment of extracted groundwater by air stripping and chemical prec1p1lation does not
address the scmivolutile organic hazardous substances present in tJle groundwater. The treated
discharge should be analyzed for these compounds and must meet all Federal, State, and local
discharge requirements.
(5) During soil confirmation sampling activities additional sampling will be necessary to confirm
Arca 3 is not contaminated. Limited sampling was conducted in Area 3 during the Remedial
Investigation. Page 55 of the ROD should be revised to incorporate the following. A soil
boring should be installed near MW-104 and samples collected by compositing 2.5 foot intervals
continuously lo 12.5 feet below ground surface (5 samples). These samples should have a
complete TCL/TAL analyses performed. The MW-104 location was selected because (1) the
groundwater from this well showed low levels of contamination with lead and chromium, (2)
a "black" horizon was noted on the boring log al 0-11 ft. in MW-104 and 5-6 ft. in MW-207
An E.qual Opportunity Affirmative Action Employer
Ms. Darcy Duin
6 July 1992
Page Two
(6)
(7)
• •
(uncertain if due lo anaerobic conditions or due lo contamination), and (3) MW-104 is centrally
localed in Area 3.
Since Ralllcsnake Branch was not sampled during the Remedial Investigation, samples should
be collected during soil confirmation sampling. Sediment and surface water sampling should
be conducted on the stretch of Rattlesnake Branch in which site waste samples should also be
collected for comparison. A full T AL/TCL scan should be performed on the sam pies.
Confirmation samples for soil and groundwater must demonstrate that total risk from
contaminatiori should not exceed a lxlCf excess cancer risk or a Hazard Index of 1 for eaeh
e00tamiHaHt preseRt at the site. Many hazardous substances present at the site were not
included in the cleanup level summary tables. These contaminants must be addressed. Also,
contaminant concentrations in confirmation soil sample TCLP leachate should not exceed the
North Carolina Title 15A NCAC Subchaptcr 2L standards. If these cleanup goals arc
determined not to be achievable, residual contamination must be recorded on property deeds.
(8) Page 114 indicates that treated soils will be analyzed for metals. These soils should also be
analy-Led fo"r all contaminants present in the waste to confirm that the treatment was effective.
CYJ:sds
(9) Table 24 provides some cleanup levels for soils. Cleanup levels for metals should nol-8l<€eee
be lower than demonstrated naturally-occurring concentrations.
Please do not hesitate to contact me at [phone] if there arc any questions about these comments.
Sin.ccrcly,
~~~ v1;;:v5--u{
Charlotte V. Jcsneck, cad
Inactive Hazardous S1 es Branch I Supcrfund Section
Allachmcnls
• •
State of North Carolina
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
WilLiam L. Meyer
Director
DATE:
FROM:
TO:
RE:
FAX TRANSMITTAL RECORD
___________ , Solid Waste Management Division
___________ , Solid Waste Section
---,---------' Hazardous Waste Section
C ft Ci I~ lei I )c )r-511 (c lr, Superfund Section
(I v· C
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Number of pages (including cover)
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Confirm receipt of document(s):
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Division of Solid Waste Manaoement [phone] C O '' f-'' cf-'1 u v
Solid Waste Section "' [phone] ° r"\ . 0 v" u ,t1 111 u1 /5
Hazardous Waste Section [phone] ° ,\ J-/, C r:-i '1 C/ J
Superfund Section [phone] A O /;, ~ n,:; I] 1
An [.qu.J Opporrunlty Affirmative Action Employer
1.=.C1f'F I Rf'lHT l 1]H Li '3T
RECE!UER: 404 347 lt,95
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• •
State of North Carolina
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
Ms. Darcy Duin
Remedial Project Manager
US EPA Region IV
345 Courtland Street, NE
Atlanta, GA 30365
6 July 1992
RE: Comments on the Draft Record of Decision
Potter's Septic Tank Service Pits NPL Site
Maco, Brunswick County
Dear Ms. Duin:
William L. Meyer
Director
We have reviewed the Draft Record of Decision for the above site received on 17 June 1992. Since the
draft we received was not a complete copy and since we have not yet received a response to our comments on
the Remedial Investigation Addendum, Draft Feasibility Study, and the Proposed Plan ( comments attached for
your reference), we are unable to provide a complete set of comments on the Draft Record of Decision at this
time. We plan to provide additional comments when we receive a complete copy of the Draft Record of
Decision. The following arc our comments at this time:
(1) Additional comments on the Baseline Risk Assessment have been provided by the North
Carolina Environmental Epidemiology Section (attached).
(2) Please pr0\1de the Responsiveness Summary referenced on page 15 of the ROD.
(3) A greater volume of soil may very likely require treatment than is proposed in the ROD. The
ROD should not limit the amount of soil requiring treatment.
(4) Treatment of extracted groundwater by air stripping and chemical precipitation docs not
address the semivolutilc organic hazardous substances present in the groundwater. The treated
discharge should be analyzed for these compounds and must meet all Federal, Stale, and local
discharge requirements.
(5) During soil confirmation sampling activities additional sampling will be necessary to confirm
Arca 3 is not contaminated. Limited sampling was conducted in Arca 3 during the Remedial
Investigation. Page 55 of the ROD should be revised lo incorporate the following. A soil
boring should be installed near MW-104 and samples collected by compositing 2.5 foot intervals
continuously to 12.5 feet below ground surface (5 samples). These samples should have a
complete 1 CL/TAL analyses performed. The MW-104 location was selected because(!) the
groundwater from this well showed low levels of contamination with lead and chromium, (2)
a "black" horizon was noted on the boring log al 0-11 ft. in MW-104 and 5-6 ft. in MW-207
An f.qua.l Opportunity Affirmative Action Employer
• •
Ms. Darcy Duin
6 July 1992
Page Two
CVJ:sds
(uncertain if due to anaerobic conditions or due to contamination), and (3) MW-104 is centrally
located in Area 3.
(6) Since Rattlesnake Branch was not sampled during the Remedial Investigation, samples should
be collected during soil confirmation sampling. Sediment and surface water sampling should
be conducted on the stretch of Ralllesnake Branch in which site waste samples should also be
collected for comparison. A full TAL/TCL scan should be performed on the samples.
(7) Confirmation samples for soil and groundwater must not exceed a lxHY excess cancer risk or
a Hazard Index of 1 for each contaminant present at the site. Many hazardous substances
present at the site were not included in the cleanup level summary tables. These contaminants
must be addressed. Also, contaminant concentrations in confirmation soil sample TCLP
leachate should not exceed the North Carolina Title 15A NCAC Subchapter 2L standards. If
these cleanup goals are determined not to be achievable, residual contamination must be
recorded on property deeds.
(8) Page 114 indicates that treated soils will be analyzed for metals. These soils should also be
analyzed for all contaminants present in the waste to confirm that the treatment was effective.
(9) Table 24 provides some cleanup levels for soils. Cleanup levels for metals should not exceed
demonstrated naturally•occurring concentrations.
Please do not hesitate to contact me at [phone] if there arc any questions about these comments.
Sincerely,
dl~v·tlt . L lvJ-/t
Charlolle V. Jesneck, Hid ~ ·
Inactive Hazardous Sites Branch
Superfund Section
Attachments
• ..if:~;. ,-f·•·1c··· .. "~-0• l~ --'tj'\?·: -~J .Y(~\J/8, '•}~l{<:
'•<,.:.'.,',~:;:~_-_:i::::+···/
•
State of North Carolina
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 19 June 1992
M E M O R A N D U M
TO:
FROM:
Perry Nelson, Chief
Groundwater Section
Charlotte Jesneck
Inactive Hazardous Sites Branch
William L. Meyer
Director
RE: Request for Review and Comments on the Potter's Septic
Tank Service Pits NPL Site Draft Record of Decision
Attached are three copies of the Potter's Septic Tank Service
Pits Draft of Record of Decision for your review. Please forward
one copy to the Water Quality Section and one copy to the Air
Quality Section for comments. The US EPA has requested that we
submit comments by 7 July 1992. All comments should be sent back
to our office so that we may submit one package to the US EPA.
Please contact me at (919)
additional information or will be
Thank you for your assistance.
CJ/yw
Attachments
733-2801 if you require any
unable to meet the deadline.
A,, [qu.aJ Oppom.mity Affirmative Action Employer