DOC:  9443.11(84)
Key Words:    EP Toxicity



Evaluation of EP Toxicity on the Basis of Total Chromium

Miton A. Cerny, Plant Engineer, Iowa Industries, Inc.,
P. 0. Box 768, Burlington, Iowa  52601

Barbara L. Bush, Environmental Protection Specialist, Waste
Identification Branch
Source Doc:   #9443.11(84)

     EPA will continue to evaluate EP toxicity on the basis of total chromium,
rather than on the basis of hexavalent chromium only.  The decision is based on
concerns raised over the potential for both trivalent and hexavalent chromium
to leach from landfilled wastes and subsequently contaminate drinking water
sources.  A waste that fails the EP toxicity characteristic for total chromium
is considered hazardous.

  r^i- ' >.
 f    f
                                                   9443. 11 I

            WASHINGTON. D.C.  20460
 -.    "'
                                                    SCLIO WASTE
                                                     RE:  WIBBB0621

  Mr. Miton A. Cemy
  Plant Engineer
  lova Industries, Inc.
  P. 0. Box 768
  Burlington, Iowa 52601

  Dear Mr. Cemy:

       This letter is to confirm our telephone conversation of
  October 29, 1984, concerning the total chromium levels  reported
  in the exclusion petition submitted by Iowa Industries  for
  dewatered solids from electroplating and pickling operations,
  presently listed as EPA Hazardous Waste Nos. F006 and K062.

       The data presented in the petition demonstrates that your
  waste typically and frequently exhibits the Extraction Procedure
  (EP) toxicity characteristic for total chromium.  In particular,
  the data in your petition indicates that total chromium levels in
  the EP extract from your sludge are variable, ranging from 1.0 to
  65 mg/l.]_/  Since samples of Iowa Industries' waste fails the E?
  toxicity characteristic for total chromium, the waste is considered
       Until as recently as one month ago, it appeared likely that
  the Agency would change the basis of the EP toxicity characteristic
  from total chromium to hexavalent chromium./  However, recent
  decisions at EPA indicate that the proposal will not be made
  final; in fact, the Agency is making preparations to withdraw
  this proposal entirely.  This decision is based on concerns.
  raised over the potential for both trivalent and hexavalent chromium
  to leach from landfilled wastes and subsequently contaminate
  drinking water sources.  Therefore, EPA will continue to evaluate
  EP toxicity on the basis of total chromium.  Based on this  decision,
  Iowa Industries' petition requesting a delisting of their  electroplating
  and pickling waste would be denied.
   ]_/  Total  chromium  levels  reported were  1.0,  18, 65, 3.7,  30,
      and  50 mg/1.

   2/  The  original proposal  was made October  30,  1980.   (See 45  FR
      72029.)                                                    ~~


     However, if Iowa Industries  can modify its  manufacturing
 process or treat the waste to decrease the total chromium in
the EP extract,  then the delisting petition can  be reconsidered.
The Agency is now using a Vertical and Horizontal Spread (VHS)
model to predict worst case contamination levels in well water
500 feet from the "contamination source.  The VHS model assumes
an in-line source-to-receptor dispersion and includes factors for  the
concentration of the constituent  in the EP extract and the total
amount of waste to be land disposed.  According  to the VHS model,
in order that the concentration of chromium at the receptor
well not exceed the National Interim Primary Drinking Water
Standard of 0.05 ppm, the concentration of chromium in the EP
extract cannot exceed 2.5 ppm, using the maximum volume of waste
generated annually at your facility. 3/  If Iowa Industries can  .
modify its prodecures to obtain this level or lower of total chromium
in the EP extract, then the petition can be reconsidered.
     Since you intend to attempt  to lower the total chromium
levels in the EP extract, we will keep your file open until we
receive additional data from you.  In the event that chromium
cannot be lowered to the specified levels, we will be forced to
deny your petition.  However, before a denial notice is published
in the Federal Register, you will be given the option to withdraw
your petiton.

     I hope thac this letter more fully explains the position
of Iowa Industries' delisting petition with regard to the total
 :hromium issue.   Please keep me informed of your treatment progess
and call me at (202) 382-4690 if you have any questions.

                         Barbara L. Bush
               Environmental Protection Specialist
               Waste Identification Branch (WH-562)
 3/  The Agency will  be  asking for public  comment on  the VHS model
    when  it  is published  in  the Federal Register with  the next package
    of proposed  exclusions sometime  before January 1,  1985.  Any
    comments  received may lead to procedural  changes'within the
    model, but are also not  expected to result  in significant