Document peN3ZeR5zG0o0xzDXDxv8onnd

i. Wc v/ouJd not mislead the EPA to suggest that this is the only alternative for control of the .slurry blend tank vents. Speculative designs have been piopor-ed for storing unslripp :d slurries in atmospheric tanks without a normally operating vent. The invests'., ut would be substantially less than the range above, but the emissions would not be affected substantially because ag*.in the contained mono::'.- : v.-<y.i)n nh,.;: most part be released in the dryer. We n o'et the use of qmlibd term:; in describing the affect on emissions. Due to other priorities, specific data on relative quantities vented is limited and questionable, i-spr.ci.dl/ rrguid to sampling and analytical procedures. Direct data is not available because installation of control systems is incomplete. Although subst-cninl effort toward calculation of emissions has been attempted, we would bo reluctant to testify to their accuracy without commercial scale data for verification. We also suggest that the slurry blend tank vents are a critical control area for compliance with a very stringent OSHA regulation. We do not anticipate elimination of routine visual level verifications in existing plants; the technology is not known. One alternative for' protection of operating personnel is to collect the vents which must then be dispersed. Substantial investment has already been allocated for such systems. Add-on controls would require substantial additLon.il investment. The prefered alternative would be to install the system to eliminate the normally operating vents and^^ggag divert, the emission to the dryer. Here again, wn find that- we ar.frffeAedTyiprv little in benefit, but substantially complicate the. opera:nifty of rh'' plwg)> Another most important factor for consideration ^ the'ieapn^atfsB**. intrinsic safety of the process after control revisiqrfek yjm induced-draft tank vent system can be designed to preclude thc^x^stdrice of flammable mixtures in the slurry blend tanks. Add-on control device's'' for induced-draft systems are substantial more expensive than for natural draft systems, but the natural draft system would not nw< ssnrily prevent the formation of flammable mixtures. In addition, a central add-on control device would through connecting lines subject all slurry blond tanks to a fire should it occur in one. An induceddraft system would preclude this disastrous potential. We also have cocu iu on Exception (c)(7) in Paragraph (c)(6). Paragraph (c)(7) refers to relief valves "in vinyl chloride service. " We suggest that by definition no w-1 following the stripper is "in vinyl chloride service. " The slripp.gr itself is border-line depending on whether the RVCM contained in the viator phase and in the solid 1'VLJ is considered "in the liquid state. " This comment also applies pat Hally to Exception (c)(9), in particular to: (i), (ii), (iii), (iv), and (vi). The rnr. iud. r of paw;- q>h (.!(')) jn expected to add little to the control of er. 1 saioi.s. \\v would n.#t expect lo encounter any violation of (c:)(*!)(v) or (c)Cb(vj,i) ,,fb s |ho It:.:; bi en ."dripped lo less than -100 ppm. We m.gg. :;t th .t (<-)p.M{7) : T d following the stripper would also pi (-(hi. ;iy lilt],. ;;; t, ,. f < it.iusi. ...c reduction but could contribute Stibrlanl'ially to the costs nf .id i '. i"i 'ring Lli'' regidaiion. BFS 0091 We suggest that 111r> CPA consider the '100 ppm in slurries in the enmo manner as OSIIA has :;tj 1 a no-action level at 0. 5 ppm. We feel that these level;; arc likely lo he consistent esjw dally downstream ai^vt^ dryer. Speed fie, illy, we suggest that l'tiiuiji ap!i (')(6)>be revised in Helete and the remainder lo be rewoided to give a n<.-notion ltyfef. we as an Industry can work le-verd e. and that will achieve l!i>*\l!lVt^sj bargd on emissions and eliminate the substantia) costs of eonlJiii^^cjTTtionitcring. Oi vV - "v.w* -i i* May 19, 1975 C. P. Loechelt I! i: !f i! iI j. j; ii BFS 009140