1 DR. AURAND: You want a number for a representative metal 



2 concentration in a mud? 



3 DR. TEAL: Soluble metal. 



4 DR. AURAND: Soluble. 



5 DR. TEAL: Only a small fraction is soluble. 



6 DR. AURAND: Yes. What I've got is just--well, let me keep 



7 looking. What I've got is a number for a total concentration. 



8 DR. TEAL: We can look at the total. If the total turns out to be 



9 small, then the soluble can't be worse. 



10 DR. AURAND: This is milligrams per kilogram, two values. The 



11 source is either the shale shaker, and in that case it is 70 percent 



12 solids, or the fluid discharge, which is 21 percent solids. The numbers 



13 were 44 mg/kg for chromium. Zinc and chromium were the highest, 44 



14 mg/kg chromium at the shale shaker and 191 in the fluid discharge; for 



15 zinc, it was 80 mg/kg in the shale shaker and 50 mg/kg in the fluid 



16 discharge. 



17 DR. BUTMAN: What is the total kilograms of discharge for a 



18 typical well? 



19 DR. TEAL: Mg/kg of what? 



20 DR. AURAND: The NAS didn't do a great job with labeling their 



21 tables, but it looks to be the material either in the fluid discharge, 



22 the pipe discharge of muds and cuttings or the materials collected on 



23 the shale shaker. In the one case, you would have the liquid discharge 



24 of mud and, in the other case, you would have the discharge for 



25 cuttings. 



26 DR. TEAL: Let's assume that it is the higher number and it 



27 represents stuff that is discharged. 



28 DR. AURAND: Well, they both would be discharged. 



29 DR. TEAL: Yes. 



30 DR. AURAND: But, this is where they are separated, because they 



31 are trying to recycle the mud, so they run it through the shale shaker 



32 to get the big stuff out. The big chunks have the one concentration and 



33 the fluid mud has the other concentration. 



34 DR. TEAL: The mud would have the higher concentration? 



293 



