NCD980602163_19961210_Warren County PCB Landfill_SERB C_Re Dispersion Modeling for Landfill-OCR

Air < }ualit v Division ' .
December I 0, 1996
TO: I .aura Butler, Assisram Chief: Pem1ining Section
tf/¥-;,
FROM: Tom Anderson;~eteorologist, AQAB
THROUGH:~ Roller, Supervisor, AQAB
SUBJECT: Dispersion Modeling for \Va1Ten County PCB Landfill
\Varrenton, NC Warren County
Per your request, T have conducted a screening-level dispcrsior. modeling analysis for emissions of
PCBs at the Warren County PCB Landfill. Potential emissions of PCB.s occar from a single gas
vent located in the center of the landfill. iv:aximum modeled impacts \Vere less than 0.1 v..-o of tl1e
ann ual AAL specified in 1\CAC 20 . ! l 00.
E:nissions of PCBs ~)ccur fron:. a 4-inch diameter PVC standpipe protruding througb the cap of
the landfill \Vhich is used to vent biogenic emissions from the facility. En)iss1ons arc ~xpected to
occur at or nea!' ambient temperature wirh an assumed exit velocity of .01 m/s (due to the
J'-, .,,. ...... J f ,1,:1~!li\~ .mi,). A.Iii !!!l!.~iuuiu111. ,ruuo of lJ. l o D grumckoo. (obrnin ild froni thi FP iii
research study ;::,aper) was used in the analysis.
SCREEK3 (96043) was used :o evalt:.ate simple terrain impacts from the vent. Sine~ the la.nd
around the lancfill i:; generally of lower elevation and due to the low re1e;.:se heighr and ambient
namre of the emissions1 complex terrain was not modeled. Receptors were placed at the ciosest
distance to the fence line ( 45 meters) and extended outward to apprnx.irnat-~ly 3,000 meters. The
maximum impact of 7.4 e-7 mg/m3 occurred at the fence line and is well helow the annual A.AL
or 8.3 e-5 mg!r~13.
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