NCD980602163_19790104_Warren County PCB Landfill_SERB C_Applocation to Dispose of Contaminated Soils-OCR

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SL\TE OF NORTH CAROLINA
APPLICATION TO DISPOSE OF SOIL CONTAMINATED WITH ?CB'S AT A SELE CTE J
SITE Di '.-iARREN COU~TY, NORTH CA.201 "::NA
PART I
The State of No rth Carolina is faced with the ?roblern of disposing of
app roximately 31,000 cubic yards of soil contaminated jy PCB's which now lie~ on
state highway shoulders in 14 North Carolina counties. In addition to this yardage ,
the r e is approximately 8,000 cubic yards of cont~minated so il on t he ~art Jr2gg
Reservation which is to be considered as oart of the wast(> st r eam to ue dC:!liverecl
to the approved di s posal site.
A site has been l ocated in \·!a rren County and is situated on prope rty ':Jelongi.ng
to Carter c. Pope and his wife, Linda~-Pope. Of the prope rties offered to be
investigat2d as po ssible disposal si tes, this si::e. is ::he he st av..:ilable zmd is
the s i t e f o r ;.J h i ch the S ta l e o f ~fo r th C a r o 1 i r. a i s a p p i. y in g t o E? ;\ f o r a p e rm i t .
In comparing the characteristics of t his site with :he technical requir~~cnts o[
EPA, th is site has the be st feature s available in regard ~o soil ~nd wate r data .
Gr eater detail will 'oe provided on the soil c1nd ,;at t:!r ciatc:i later _-;n during this
presenta t ion . The site is located south of ~arrenton or: SR 1604 in the Afton
Community. Other favorable E.::at"Jres inc lude its ;-::odcr2cc, copogr;:i.,)hical re:i ief,
land availability, i s olation featu res, acce ss f rom t:1-:c s:.,,::e maintained high·;Ja y
system, re lative location to the total spil l ~rea, and si tC:! preparation . Su r fa ce.
dra ina ge from the site leads co Richneck Cr eek, a
warren Coun t y . The nearest resi dents to the site
1 he site infer.nation has been revie' .. ;ec b~· the u. S. Dep artment
and certific ation has been p rovided by their U.S. Ceola;ic3l Survey Offic~ that
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2 e e
the ~ite is above the 100-yca r flood level . The best technical means available
for the r emoval of the soil from the highway shoulders r equires a cut two feet
wide a nd three inches deep to oe removed from the h ighway shoulders contaminated
with PCB' s. A demonstration pick up of one mile of t hi s material has produced
results to show that the conglomera te of soil, activateci carbon, asp halt , PCn'ss
grass, and other incidenta l discards in the two foot width to range from
approximately 210 ppm t o 380 ppm of PCB's in the total ~ass . This concentration
ba rely qualifys as a PCB problem when considering the disposal p roblew ,done .
The site is for one time disposal only and the req~est fo r :i permit t o EPA
is for the disposal of the soil contara inated with PCB's only.
No rth Carolina statu tor y requireme nts specify thaL t.he sit:e 1 s descript ion
is to be recorded in the ~egister of Deeds office in the county i.n which the site
is located and to be so described as Lo protect future proper ty owners.
The site is proposed to have adequate an d controlled access at all times.
Site security is :o be enhanced by encl osing the disposal area with a s ix-foo t
chain link fence which will be topped with barbed wire .
The State of No rth Carolina will have its inspectors on the sc ene during
all disposal operations.
Upon rece ip t of approval f rom EPA, detailed plans a nd specifications fo r
site construction and c omp le tion wi ll be in i tiated and sta te pe r mits wi l l be
obtained and issued by the North Carolina Department of Human Re sou rces. As
request
outlined in our per.nit/, the t entative schedule i nclu des c ompletion of dctc1iled
plans a nd specifications af t er receipt of the tentat:ivc approval fr om EPA whic h
is expected by January 25, 1979 . Allowing t ime f o r review and approva l o~ the
dctc1ilecl plans and spccir·icati.ons, fir1a l approv;:i l i s r::x,1(;<..:t.ed frc,~ !:P,\ by
Ma rch 7, 1979. The construction schedule may v;:iry with weathe r con ditio~s ,
however, approximately 90 days after the site pn::pa r ation js c ompleted j ,-1s
ant ic ipa t ed that the si:e will have received all of the soil cont.;:iminatcd 1.,1i th
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PCB to be disposefof at his site and the site w'l :e !osed in accordance with
the detailed specifications .
It is hereby requested that EPA give favorable review and approval to this
application for the disposal of soil contaminated with PCB's at the specified
site in Warren County.
Certified laboratory results of permeability testing are hereby ?resented
to the Regional Administrator for inclusion into the permit application package .
Further detail on these test results and other soil data will now be presented.
Presented by: Jerry c. Perkins , Head
Date:
Solid Waste & Vector Control Branch
Sanitary Engineering Section
Division of Health Services
N. c. Department of Human Resources
January 4, 1979
PAB.T II •
SITE TECHi'UCAL REQUIRE~·fENTS
Technical requirements for the conceptual engineering 1,es~qn of the proposed
landfill management of soil-PCB mixtures includes detailed evaluation of site
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suitability with respect to soils, hydrology, topography and flood protection. ----~==============~ -=..., -:::::---~;;_
A technically suitable site accommodates the development of a design that prirna:-ily
excludes surface and subsurface water contact with the soil-PCB mixture .
A ?rocedure for ,.aive.r of a technical requj_reme:1t is available if evaluation
of site characteristics indicate the application cf sound engineering ?ractices
can afford an eaui valen,r:. 1 evcl of protection for envi ronraen cal hea~. th. The waiver
procedure permits flexibility i n consideration of unique sit:e! specific cha,act~r-
is tics.
SOILS
Surficial soils reflect site geology which consist of metamorphic mica gneiss
rock which are deeply weathered in place, forming chick suriiicial layers of brown-
red clayey residuum soils. Upper-surface soil materials are classified as clayey
(A-7 to A-6 AASHO system). An increase in silt and sand content (A-4 ~o A-5)
directly above the weathered geneissic formation is indicat:ed by soil borjng data.
Therefore, on-site soils are not classified as representative of a large area c~ay
pan. Proposed sites chat are not characterized by clay pans are required to hav~ a
high clay and silt content, must include a design for a thi:ee-foot comp~cted soil
-·-7 .., liner below the soil-PCB mixture , have a permeability ot 1.0 x 10 c~/sec, > ~o
percent passing a ~o. 200 sieve, liquid limit2.30, plastidty indl.!x2._1S.
Si ::.2 soil .:i.nd proposed de.sign parameters exc-.~ed cr.ese minir:'.:'.71 c :~~ ,:i ren:eri cs and
include comp~cted soil liner of five fe~t, pern~abilicy of 2.05 x 10-S cm/sec,
65 percent passing No. 200 sieve, average liquid limit of 50, average.plasticity
index of 18. ~-1axir.1um ciry density and ?crneabilicy at 95 percent maxi:num ci:.-y density
soil tests have been certified and are added to chis application.
An artificial liner with a thickness greater than 30 mil is required for
proposed sites located in are2s not characterized by clay pans. The State o f
Jorth Carolina is requesting a waiver for this requirement. The applicaton of
good engineering practices and design alternatives for the artificial liner will
not present an unreasonable risk of injury to health or the environment .
Engineering and design a lternatives include:
planning the landfill as a one shot (90 days open) special
operation for a soil and ?CB mixture as compc1re<l to a long-
t erm commercial facility disposing of con·centratc:cl liquid PCB .
desi gn to exceed the required compacted clay liner jn both
thickness and penneability param-:cters.
an artificial l i ner (plastic) may be ruptured during placement
and is not guar anteed against long-term deterioration, while
soils are more permanent .
placement of a 10 mil plastic liner on top of the proposed
landfill.
design to include a compacted clay llner over the pJ.astic liner,
the addition of top soil to support vegetati ve growth above the
clay liner, plus providing a surface g radient and drainc1ge ditches
are
to remove surface water . All of the above/designed to effectively
prevent any surface water infiltration into the ]Rndfill.
It is reiterated that these design alternatives, for an artificial liner
below the soil-PCB mixture, will afford more protection to hunwn health and the
environment.
EYDR0L0GY -T0POGRAPHY
The proposed landfill site is located in an area of moderate relief and on
the crest of a ridge which slopes in a radial pattern to topographic lows. Slte
surface 2.nd beological topography are predicted ::o be relatively similar. Therefore ,
surface drainage and g roundwater flow is in a radial pa ttern away from t he site
with ultiwate di scharge into Rich Neck Creek and tribut~ries.
Surface runoff is promoted by existing surface gradien t and infil tration is
decreased due to inwash of fine textured surface soil materials into soil pores
under rainfall events. Surface runoff will be increased under controlled con-
ditions with a subsequent reduction in infiltra tion by the e ngineered manipulation
of the site. Recharge of groundwater from surface water sources is not considered
to be a major s ource of rechar ge ~,i th existing :; i t e conditi.ons and will be reduced
by the proposed desi gn . This will result in loweting of any groundwater existing
below the site. The conceptual design insures no hydraulic connection between the
site and surface water .
Groundwat er below the site is associa t ed with the geneissic rock fornation and
"sand rock" (weathered rock) a bove the fom.ation . Existing wells on similar
topo graphic positions in the area indicate a static g r o undwater level of 40-47 feet
below ground surface in "sand rock". Groundwater encounte::red in the soil borings
on the site indicate the upper limits of the groundwa t er . Examinatlon of historical
rainfall, evapo-transpiration and soil colors indicate that the existing water table
elevations are historically representative. Based upon the transm.issivit1' of
"sand rock'' water-bearing :naterials, water table hydraulic g radient, capillary rise
calculations and no site under flow from off-site sources, a maximum 3-foot upward
fluctuatiorr of existing groundwater is a design parameter . This p arameter is
flexible and separation from groundwa ter can be controlled by limiting the maximum
excavation elevation. The conceptual design separation of the soil-PCB mixt~re and
grot1nd1-.r2.tc2r is 13 feet.
A hydrological r equiren~nt for site selection is that the site is t o be 50 feet
from the neare§t groundwater . Groundwater is within 50 feet or less from the surface
in essen tiall y all areas s uitable for landfilling soil 2nd PCB mixtures. ~orch
Carolina is requesting a waiver from t;1is im;nac tical if not impossible restriction.
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The application of good engineering practices to prevent movement of the landfilled
soil-PCB mixture is the major inherent design requiremen~ and the application of
these principals as a basis for granting a waiver will not present a n unreasonable
risk to health or the environment from landfilling soil-PCJ3 mixtures. The reasons
stated for the liner waiver are also applicable.
FLOOD PROTECTION
Flood protection is provided in that the site is located approximately 70 feet
above the maximum 100-year flood water elevation . Surface water pro tection is
provided by including diversion of all surface runoff fi·orn .:1 twenty-four hours
25-year stonn.
It is concluded that the proposed conceptual design rneC:!ts or e>:ceeds the
technical parameters established for landfilling soil-PCB mixtures and provides
adequate protection to health and the environment.
Mr . 0. W. Strickland will discuss the specific site design, construction, and
main tenance .
William L. Meyer
Environmental Engineer
Solid Waste & Vector Control Branch
Sanitary Engineering Section
Division of Health Services
N. C. Department of lluman R~sources
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