From: 	Peter Westlin/RTP/USEPA/US 

To: 	Rochelle Boyd/RTP/USEPA/US@EPA 

Date: 	08/09/2010 02:24 PM 

Subject: 	Re: Fw: Information Collection Request for the Secondary
Aluminum Production Source Category



Based on the FR notice (  HYPERLINK
"http://www.epa.gov/fedrgstr/EPA-WATER/2007/March/Day-12/w1073.pdf" 
http://www.epa.gov/fedrgstr/EPA-WATER/2007/March/Day-12/w1073.pdf )
issued by the Office of Ground water and Drinking Water, I determine
that Method 3500 Cr-C or D would be acceptable alternatives to Method
218.6.   

Peter Westlin

Measurement Policy Group

OAQPS, SPPD

919-541-1058

---- Forwarded by Rochelle Boyd/RTP/USEPA/US on 08/02/2010 03:40 PM
----- 

From: 	jeffrey.hummel@gm.com 

To: 	Rochelle Boyd/RTP/USEPA/US@EPA 

Date: 	08/02/2010 02:26 PM 

Subject: 	Re: Fw: Information Collection Request for the Secondary
Aluminum Production Source Category



Rochelle,

My lab informed me that they use method 6010C for non-Hg metals because
they do not put "dirty samples" such as baghouse dust into their 6020
MS.  

They also use 3500CR-D instead of 218.6 for Cr+6. 

Are these methods acceptable?

Also, what does "IDL" mean?  

Please advise,

Jeffrey S. Hummel, MS, CHMM

Sr. Environmental Engineer

(812) 279-7271

(812) 279-7367 (Fax)

  HYPERLINK "mailto:jeffrey.hummel@gm.com"  jeffrey.hummel@gm.com 

General Motors LLC

105 GM Drive, Bedford, IN 47421

