Document gbo4BqgxGZ0wXe1YyrgR25rDe
Tho potential environmental hazards of biphenyl with low levels of chlorination are different than biphenyl with high levels of chlorination and, therefore, should receive different effluent limits. It is possible to define PCBs for the purpose of setting effluent limits, as mono, di, tri, tetra, penta and hexachlorobiphenyl, the major isomer groups o^ all PCBs. Cl7 to Cl^j biphenyl compounds may be too non-volatile for conventional GC-MS analysis (See attachment, "Polychlorinated Biphenyl (PCD) Analysis.") Individual isomers within each group should be treated alike unless future data regarding environmental hazard shows specific isomers to be significantly different from the group.
Table I provides data from which an alternative approach to establishing effluent limits for these PCB groups has been derived according to their bioconcentration factors. Values for partition coefficients in Table I were calculated accord ing to the method of Leo, et al.* The bioconcentration factor for tetrachlorobipneny1 in rainbow trout has been experimentally determined (preprint by Branson, et al. attached). Biocon centration factors for the other chlorinated biphenyls were calculated according to the method of Neely, et al. (Preprint attached.).
The water levels that impact unsafe residues in fish can be estimated from the relative bioconcentration factor at steady state as follows:
C
BF
Cy * Concentration of chemical in fish flesh that is . unsafe, e.g. 5 ppm for PCB
BP * Bioconcentration Factor
" Concentration of chemical in water
The water quality criteria for PCB's shown in Table I were calculated using this approach. Thus, water of acceptable quality for a fish habitat should bo realized if the concentration of PBC Isomers (Cw . ..C^, ) satisfy the equation:
*A. Leo, C. Hansch, and D. Elkins, Chem Rev., 71^ 525 (1971).
HONS 040561
590 + -1400 C,,2 + 3400 Cy + 12,300 + 19,000 CWs
+ 47,000 C,,8 i 5 mg/1
'
c'
'
After designation of acceptable levels of pcb's in the
receiving water, allowable discharges from point sources
be set in individual NPDES permits.
"
should
How does this alternative approach differ from that proposed by
the EPA, 40 CFR Part 129?
.
1. The concept of pounds per day in effluents of PCB's like Aroclor 1242 or 1254, etc. would be discontinued.
2. The bioconcentration factors, and, therefore, water quality criteria and effluent limitations, are based on the properties
Of individual PCB isomer groups. The bioconcentration ' factor of 200,000 used to calculate effluent limits in the
proposed regulations is not characteristic of all members of this class of compounds.
3. The effluent limits are based on water quality criteria. The allowable discharge from each point source would be set at the local level and stipulated in the NPDES permit.
Dean R. Branson March 4, 1974
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TABLE I
WATER QUALITY CRITERIA FOR CHLOROBIPHENYLS
Partition'3' Coefficient
Bioconcentration Factor Cp/Cw
Concentration (iig/1) of PCB in water leading to 5 ppm in trout flesh
: o! Chlorobiphenyl r * !*
i.
-i
.
4.9
Dichlorpbiphenyl 1 ; .. j ,
' 5'6
i. ;. .
Trichlorobiphenyl n r 6-3
: ;;
,:
i i, i
590 (b>
l,400(b)
3,400(b)
PI 8.5
"l 3.6
1.5 ' |
Tetrachlorobiphenyl , Pentachlorobiphenyl
: 7.o r*
: 7.7
, i !'
! :: ! 12,300 + 2,3oo(c) 19,000(b)
0.40 0.26
! ;
Hexachlorobiphenyl
8.4
46,000(b)
' 0.11
SNOW
^Calculated according to the method of Leo, et al. (Chem Rev., 71, 525 (1971)) assuming n = 0.7 for each aromatic chlorine, and confirmed by adding * values for chlorobenzenes.
^Calculated value from Log BF = 0.56 Log P oct + 0.124 (See attached preprint by Neely, et al.) .
(^Measured value (See preprint by Branson, et al.) .
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