GCI TECH NOTES ©
Gossman Consulting, Inc. recently commented on the draft SW-846 update that includes numerous new and revised analytical methods. This issue of GCI Tech Notes provides the comments GCI made to EPA regarding this new draft of SW-846. Support for this effort from Holnam Cement and Continental Cement is acknowledged and appreciated.
1. Numerous PCB and pesticide cleanup methods utilize hexane as an extraction/ dilution solvent. This is contraindicated by human health and safety as well as good laboratory practices (GLP) issues. Isooctane works just as well in most of these types of application. It is much less toxic and less volatile. This reduces exposure and prevents, through volatilization, excessive solvent loss during various preparation steps. If EPA really has as a driving force the protection of human health and safety, then this is one more example of a change that must be made. We would note that a similar and appreciated effort to reduce the need to use methylene chloride is evident in those proposed methods.
2. Microwave Assisted Acid Digestion of Siliceous and Organically Based Matrices - Because of the introduction of Method 3052, and possibly others as well, there is the potential for substantive changes to occur in the regulated community and increased costs. Specifically, the BIF regulations require stack testing and process monitoring if a metal is detectable in a waste stream using SW-846 methods. With this method, the regulated universe can change. Boilers using HWF which have been exempt from metal monitoring could suddenly be regulated. EPA is required by its own rules to perform economic impacts of such changes and make such studies available for public comment prior to final promulgation. As this is only an example, we believe that EPA must refrain from promulgating some of these changes to SW-846 until a thorough analysis of all similar situations is performed.
3. Section 2.1.3 - Quality Control Criteria Precedence - Reference to site/test plan specific data quality objectives (DQO) should be identified as the primary quality control criterium. General and method specific criterium should be secondary.
4. Section 2.1.1- Trace Analysis vs. Macronalysis - Excellent section - can't be said enough.
5. Section 2.2.6 - Sample Containers, Preservations, and olding Times - All sample volumes should be labeled "minimums". Many of the holding times and preservation requirements in tables are inappropriate. (Comments on specific tables/issues to follow.)
6. The existing TCLP procedure desperately needs a flow chart. The enclosed flow chart is available for use as long as the source (Gossman Consulting, Inc.) is appropriately acknowledged. (This flow chart can be found in the May, 1993 issue of HWF Notes.)
7. Section 3.1.2 - Definition of Terms - Definitions are needed for the following terms: "quantitation limits", "solids", "liquids", and "sludges".
8. Table 3-1 - Sample Holding Times, Required Digestion Volumes and Recommended Collection Volumes for Inorganic Determinations in Aqueous and Solid Samples - Footnote (b) implies a method for determining Cr (VI) in non-aqueous (organic matrix) samples, we are aware of none. (Method 3060A although demonstrated on soils, has not been demonstrated on high concentration organic matrices.)
9. Method 3050B - Acid Digestion of Sediments, Sludges, and Soils - This method cannot reliably determine total metals in the sample types listed because of the presence of various metals matrices that are not fully digested. The method should be qualified as such. Method 3050 has particularly poor recoveries for Cr, Ni and similar metals in nearly all soils and sediments because of the presence of silicates. Method 3040A frequently has better recoveries that 3050 for liquid, solid and friable solid matrices that can be suspended and aspirated in a solvent matrix. We would strongly recommend ASTM Method E926-94 Practice A, be adopted by EPA as well as energy dispersive XRF. Those are the two methods for which we have had the best recoveries in complex hazardous waste fuel samples.
10. Method 3052 - Microwave Assisted Acid Digestion of Siliceous and Organically Based Matrices - Section 1.1, second sentence is grammatically incorrect.
- Section 8.0 - What is the rationale for a having a three year record keeping requirement in this method, but not in the others!
- Why is more extensive quality control required than 3050, which doesn't work as well?
- Why is "experienced analyst" not generic to all methods? - Seems redundant.
- Method 3052 - The original developer of this methodology, Bruce Pedersen of Systech Corporation, has previously commented extensively on this method. We support all of Bruce's comments. An alternative to this method is ASTM E926 Method A. It has been used and validated for many years and can frequently obtain lower detection limits than the microwave technique because the boric acid in 3052 requires greater dilution prior to sample analysis. This method should also be adopted by EPA for SW-846.
11. Method 0060 - Determination of Metals in Stack Emissions - Section 1.5 implies that the "analyst" must be an experienced stack tester - rewording is needed.
12. Table 4-1- Sample Containers, Preservation, Techniques, and Holding Times - Preservation and holding time requirements for "Concentrated Waste Samples" are inappropriate. Ambient storage for up to 90 days is common throughout the waste management industry with no detrimental results. This requirement would impose significant costs on many facilities!
- Container sizes are sometimes too large or small depending on circumstances. More flexibility is needed.
- Holding time and preservation restrictions are inappropriate for many solid matrices. An example would be ash from a boiler or furnace. There is no need to cool to 4C or to restrict holding times to fourteen days! Other industrial process feed streams such as coal do not benefit from these requirements, yet may significantly increase costs of trial burns and similar testing. This table needs significant modifications.
13. Method 3665A - Sulfuric Acid/ Permanganate Cleanup - This is an excellent method but could use a few modifications. There should be an allowance for ending the procedure after the sulfuric acid cleanups if that is all that is needed. Also, multiple sulfuric acid cleanups frequently benefit some samples.
14. Volatile Organic Compounds by Gas Chromatography/Mass Spectrometry (GC/MS): Capillary Column Technique - The organic gas chromatography methods are good for specific classes of compounds. EPA needs a broad scan (volatile and semivolatile) screening tool. A paper on such a method is attached. (Call GCI's office if you would like a copy.) The Method 8260 would provide a good basis for this development.
15. Method 8280A - The Analysis of Polychlorinated Dibenzo - P - Dioxins and Polychlorinated Dibenzofurans by High Resolution Gas Chromatography/Low Resolution Mass Spectrometry (HRGS/LRMS) - Excellent update of this method. Toluene as an extraction solvent is a very good move. This method also contains the best guidance yet on calculation of TEQ values. - Very helpful.
16. Method 0050 - Isokinetic HC1/Cl2 Emission Sampling Train and Method 0051 - Midget Impinger HCL/Cl2 Emission Sampling Train - Ammonia chloride should be listed as a specific interference.
- For quality control reasons, there should be a requirement that impingers be analyzed for cations such as NH4+, Na+, K+, etc. NH4+ would indicate ammonia chloride interference
- guidance on correcting the data could then be provided. Na+, K+ and other cations from chloride salts would indicate filter breakthrough (failures). "Real world "industry experience suggests this is quite common.