United States [Environmental Protection Agency Office of Ground Water and Drinking Water Cincinnati, OH EPA-814N 95001 August 1995 SEPA Labcert Bulletin In This Issue In September 1992, we published a table of the regulated drinking water contaminants with MCLs, methods, etc. In this issue you will find an updated table, a brief update; on the ICR, some frequently asked questions (with answers) about the Methods Update Federal Register Notice (MUFRN) and certification guidance for PCBs. Of course, if there are any discrepancies between the table and 40 CFR, the Code is correct. As always, your questions and comments are welcome. The Editors: Edward M. Click 513 569-7939 Mary Ann Feige 513 569-7944 Caroline Madding 513 569-7402 26 W. Martin Luther King Dr. Cincinnati, OH 45268 ICR Lab Approval Update The proposed Information Collection Rule (ICR) was published in the Federal Register on February 10, 1994 (59 FR 6332). Promulgation is expected in December 1995 with monitoring to begin in early 1996. Below is an update of the lab approval process. Lab Approval - Chemistry As proposed, labs must register and apply for approval, meet specific criteria for each method, and pass one PE study to receive EPA approval. Two PE studies have been conducted and a third PE study is scheduled between promulgation and the beginning of monitoring. Laboratories registered with EPA were notified of the PE studies. Revised sections of the ICR/DBP Analytical Guidance Manual and application packages were sent to registered labs in early April 1995. Lab Approval - Microbiology Applications were sent to registered laboratories during the past six months. The applications returned to EPA are currently being reviewed. After EPA review of the applications, laboratories must satisfactorily analyze QC and PE samples and pass an on-site evaluation. EPA began PE studies for viruses in August and expects to begin on-site evaluations and PE studies for virus and protozoa laboratories in late 1995. Registered laboratories will be kept informed of EPA's progress on microbiology laboratory approval and will receive updated methods and training materials when they are available. Laboratory Approval Requests To be approved to analyze samples for the ICR, laboratories should write to the following address: ICR Laboratory Coordinator Technical Support Division Office of Ground Water and Drinking Water, USEPA 26 West Martin Luther King Dr. Cincinnati, OH 45268 For current ICR updates, call the Safe Drinking Water Hotline (800 426-4791) or E-Mail them at their Internet address: HOTLINE-SD WA@EP AM AIL. EP A. GOV. Printed on Recycled Paper ------- 1994 Methods Rule A final rule, Analytical Methods for Regulated r\Drinking Water Contaminants (MUFRN), was published on December 5, 1994 in the Federal Register (59 FR 62456-71). Effective January 4, 1995, twelve new analytical methods were approved and many methods were updated to the most recent version. On July 1, 1996, the rule withdraws approval for 38 U.S. EPA, three Standard Method and two ASTM methods. The rule also contains mandatory method modifications and optional procedures developed after the approved methods were published. These changes are described in the rule and in the document, Technical Notes on Drinking Water Methods (Tech Notes), October 1994 (NTIS order number PB-104766, telephone 800- 553-6847). Below are answers to questions we have received about the 1994 methods rule and Tech Notes. Q. Do I need a copy of Tech Notes in addition to a copy of the approved method? A. Yes, because it contains changes to about 25 approved methods and recommends modifications to several other methods. The information in Tech Notes corrects or explains procedures described in the approved methods. Q. Do I need a copy of the Code of Federal Regulations or of the 1994 methods rule to have a complete list of all currently approved microbiology and chemistry methods? A. No, Tech Notes conveniently lists all approved and to-be-withdrawn methods for primary contaminants, all recommended methods for secondary contaminant monitoring, and instructions for continuous chlorine monitoring under the Surface Water Treatment Rule. Q. The tables of withdrawn methods (Tech Notes, pp. 14 - 19) list only methods that are to be withdrawn on July 1, 1996, and not those that are replaced by a later version. For example, Methods 524.2 Rev. 3 and 525.1, which were replaced by Methods 524.2, Rev. 4 and 525.2, respectively, are not included in these tables. What is the status of these replaced versions? A. Both versions of a replaced method are in effect until July 1, 1996. EPA noted (59 FR 62461) that the 17-month overlap in approval periods for the new and old version of a method gives "laboratories sufficient time to become certified with the new" version. ALTHOUGH BOTH VERSIONS ARE APPROVED UNTIL 1996, EPA DISCOURAGES USE OF OBSOLETE VERSIONS EXCEPT FOR COMPELLING ECONOMIC REASONS. EPA listed in Tech Notes as withdrawn, only those methods for which no updated versions published by the same organization were approved. Q. Are there errors in the December 1994 methods update rule? A. Yes, we found five errors or conflicts, and four were corrected on June 29, 1995 (60 FR 34084). Please let us know if you find others. 1. The temperature method was cited differently in §141.23(k)(l) and §141.74(a)(l). It can be either Standard Method 2550B or 2550. We chose to cite it as 2550. 2. The rule states that a footnote specifying coliform sample transit times and temperatures will be added at §141.21(f)(3). ------- However, Footnote 1 in the table at 59 FR 62466 only covers transit time. This is an error and EPA has revised Footnote 1 to state that EPA encourages but does not require systems "to hold samples below 3. The correct holding time for samples acidified in the laboratory for lead or copper is 16 hours as cited in the methods and in Tech Notes (p. 29). However, this conflicts with the 28-hour instructions cited at §141.86(b)(2). Because EPA data shows that 16-hours is sufficient, we: will delete the 28-hour reference in the next revision of the lead and copper rule. 4. The methods citexl for sulfate in the regulations at §1430?) (59 FR 62471) and on page 20 of Tech Notes are correct. However, there is an error on page 1 1 of Tech Notes. Turbidimetric methods are not approved or recommended for sulfate. ASTM D5 16-90 should be deleted and SM 4500-SO4-E should be 4500-SO4-C, D. 5. The rule appears to delete the maximum trihalomethane potential (MTP) test in Part III of Appendix C of §141.30. This typographical error has been corrected. The MTP test is now cited at §141.30(g) and has been revised to delete references to EPA Methods 501.1 and 501. 2. Q. Systems may reduce trihalomethane (THM) monitoring frequencies if they pass the MTP test. If a system fails this test because insufficient residual chlorine is present at the end of seven days, may the system use EPA Method 510.1 to repeat the test? A. No. Although it is listed in EPA's laboratory certification guidance manual, Method 510.1 was never approved and it is not supported by the Agency. There is no federal provision for an alternative to the MTP test at §141.30(g). Q. Is the Colisure test complete in 28 or 24 hours? The table at §141.21(f)(3), in the 1994 rule (59 FR 62466), specifies 28 hours but some people say 24 hours is sufficient. A. Both answers are correct depending on the test result. Negative coliform results require at least 28-hours (and no more than 48 hours) of incubation to confirm. But a positive coliform result may be reported after 24 hours. Q. Must the turbidity of a sample for metals be checked? Why? A. Yes. Turbidity is one of the parameters checked to determine if an acid digestion is required. The turbidity of the unfiltered sample must be measured. It must be measured anytime after the acid preservation step is completed. Acid preservation is complete after 16 hours. (Tech Notes p.29). Q. May volatile organic chemical (VOC) samples be acidified after the sample is returned to the laboratory? A. No. The sample must be dechlorinated and then acidified at the time of collection to prevent decomposition of VOCs en route to the laboratory. (Tech Notes, p. 34) Q. In Method 504.1, the holding time has been decreased to 14 days and the requirement for acid preservation has been deleted. If analyzing only for EDB and DBCP, may I hold the sample for 28 days and do I need to add acid? What are the requirements for analysis of 1,2,3- trichloropropane (TCP) with Method 504.1? ------- A. There is a conflict between Methods 504 and 504.1. Until Method 504 is withdrawn in 1996, laboratories may use either method for EDB and DBCP as follows: Method 504 (with acid and a 28-day holding time) or Method 504.1 (without acid and a 14-day holding time). We do not recommend Method 504.1 for TCP; it is more economical to measure TCP with the other VOCs using Methods 502.2 or 524.2 (with acid and a 14-day holding time). Q. What derivatizing reagents may be used with EPA Methods 515.1 and 515.2? A. Either diazomethane or trimethylsilyldiazomethane (TMSD) may be used. (Tech Notes, p. 37) Q. I want to use the SPE procedure in Method 515.2 rather than the LLE procedure in Method 515.1. May I use Method 515.2 to measure dalapon? A. No. Dalapon is not in the scope of Method 515.2, because we have been unable to routinely achieve acceptable recoveries. We are not sure why recoveries are not as acceptable as with Method 515.1. It is possible that resin-based SPE media do not recover dalapon as well as ethyl ether extraction. The volatility of the ester may be a factor. Utah reported (August 1994 Labcert Bulletin) improved recoveries for dalapon and other Method 515.1 analytes by changing the evaporation procedure. EPA realizes some laboratories prefer SPE to LLE procedures, and are frustrated by the absence of dalapon in Method 515.2. One laboratory reports low (40%) dalapon recoveries with good precision (8%) using Method 515.2 procedures. These low recoveries may be acceptable, if they are reproducible (e.g., a precision of 20% or better) and include use of a surrogate compound to accurately track dalapon recovery under Method 515.2 conditions. We cannot rule out that Method 515.2 could be acceptable for dalapon, but we need data before we could consider revising the method. If you have data, send it to the editors of the Labcert Bulletin. Q. Ammonium chloride can be used to dechlorinate samples for THM analysis with EPA Method 551. Can it be used in other approved THM methods? A. No. Currently, ammonium chloride is specified only in Method 551 and only for THMs and haloacetonitriles. Q. Method 551 does not require acidification of the sample if only THMs are to be determined (Sect. 8.1.1), but it is not clear that this is true if Methods 524.2 or 502.2 are used. What do you suggest? A. If only THMs are to be measured, acidification of the sample is only required if ascorbic acid is used as the dechlorinating agent. (60 FR 34086 and Tech Notes, pg 53) Q. What, if any, methods proposed for withdrawal were not withdrawn in the 1994 rule because of public comment? A. EPA Methods 150.1 and 150.2 (pH), 245.2 (mercury) and 515.1 (herbicides) were retained based on public comment. Q. Are there plans for another methods update rule, and what might it contain? A. We hope to propose a rule containing new methods soon. We also wish to change the methods approval process so that future drinking (Continued on Page 9) ------- REGULATED DRINKING WATER CONTAMINANTS (a) INORGANICS PROPOSED RADS PARAMETER REGULATED Alkalinity4 Asbestos1 Chloride1 Residual Disinfectant* Free Chlorine Total Chlorine Chlorine Dioxide Ozone Color1 Conductivity4 Cyanide1 Fluoride1 Foaming Agents' Nitrate (as N)1 Nitrite (as N)1 Nitrate/Nitrite (as N)1 Odor1 pH14 o- Phosphate4 Solids(TDS)1 Sulfateu Temperature4 Adjusted Gross Alpha* Beta Particle Emitters' radioactive Cesium radioactive Iodine radioactive Strontium tritium gamma& photon emitters Radium-226' Radium-228* Radon-222' Uranium* MCL/ [SMCL]W mg/L - 7MF/L>10/zm [250] detectable [15cu] - OJ 4.0 [2.0] [0.5] 10 1 10 |3 tou | 6.5-8.5 [6.5-8.5] - [500] deferred [250] - 15pCi/L 4 mr ede/yr - - - - - 20 pCi/L 20 pCi/L 300 pCi/L 0.02 MCLG10 mg/L - 7MF/L>10jon - - - 0.2 • - 10 1 10 - - •• - deferred - zero zero - - - - - zero zero zero zero METHODS" ACCEPTANCE LIMITS11 D1067-92B, 2320B, 1-1030-85 100.1, 100.2 300.0, D4327-91, 4110, 4500-C1-D 4500-C1 D, F, G and H 4500-C1 D, E, F, G and I 4500-C1O, C, D, E 4500-O, B 2120B Dl 125-91 A, 2510B 335.4, D2036-91B, D2036-91A, 4500-CN-C, G, E and F, 1-3300-85 300.0, D4327-91, D1179-93B, 4110B, 4500F-B, D, C and E, Technicou 380-75 WE and 129-71 W 5540C 353.2, 300.0, D4327-91, D3867-90A&B 4110B, 4500-NO,-F, D and E, Waters B-1011, ATI 601 353.2, 300.0, D4327-91, D3867-90A&B 4110B, 4500-NOj-F & E, 4500-NO2-B Waters B-1011 - 2150B 150.1, 150.2, D1293-84, 4500-H+-B 365.1, 300.0, D515-88A, D4327-91, 4500-P-F, 4500-P-E, 4110, 1-1601-85, 1-2601-90, 1-2598-85 2540C 300.0, 375.2, D4327-91, 4110, 4500-SO4-F, C and D 2550 900.0 900.0 901.0 902.0 905.0 906.0 901.1 903.0, 903.1 904.0 903.1, 913.0 908.0, 908.1 2SD ±25% ±10% . ±10% ±15% ±50% ±30% ±30% ±30% ±30% ±20% ±30% ±50% ±30% ±30% ------- MICROBIOLOGICAL CONTAMINANTS VOLATILE ORGANICS PARAMETER REGULATED Turbidity* Total Conform*" E. coliu Fecal Coliform*'" Giardia lamblia* Heterotrophk Bacteria or Residual Disinfectant* Legionella' Viruses* Trihalomethanes (Total) Benzene Carbon tetrachloride Chlorobenzene1 p-Dichlorobenzene o-Dichlorobenzene1 1 ,2-Dichloroethane 1 , 1-Dichloroethylene c-1 ,2-Dichloroethylene1 t-1 ,2-Dichloroethylene1 Dkhloromethane1 1 ,2-Dichloropropaue1 Ethyl benzene1 Styrene3 Tetrachloroethylene1 Toluene1 1 ,2 ,4-Trichlorobenzene* 1,1,1-Trichloroetbane 1,1,2-Trichloroethane* Trichloroethyleue Vinyl chloride Xylenes(Total)1 MCL/ [SMCL]10 mg/L Treatment 100/lOOmL* 5% positive samples/mo11 BW1" 5141.21(0(5) 8141.74(a)(l) Treatment Treatment Treatment Treatment 0.10 0.005 0.005 0.1 0.075 [0.005] 0.6 0.005 0.007 0.07 0.1 0.005 0.005 0.7 0.1 0.005 1 0.07 0.2 0.005 0.005 0.002 10 MCLG10 mg/L - zero zero zero zero - zero zero zero zero 0.1 0.075 0.6 zero 0.007 0.07 0.1 zero zero 0.7 0.1 zero 1 0.07 0.2 0.003 zero zero 10 METHODS4'7 ACCEPTANCE LIMITS" 180.1, 2130B, GLI Method 2 TCR (9221A,B,D, 9222A,B,C, 9223, Colisure) SWTR (9221A,B,C, 9222A,B,C, 9223) Colilert, Colisure, EC-MUG" Nutrient Agar-MUG" TCR (9221E Part 1) SWTR (922 IE Part 1&2, 9222 D) 9215B(HPC) 4500 series (disinfectants) 502.2, 524.2, 551 502.2, 524.2 502.2, 524.2, 551 502.2, 524.2 502.2, 524.2 502.2, 524.2 502.2, 524.2 502.2, 524.2 502.2, 524.2 502.2, 524.2 502.2, 524.2 502.2, 524.2 502.2, 524.2 502.2, 524.2 502.2, 524.2, 551 502.2, 524.2 502.2, 524.2 502.2, 524.2, 551 502.2, 524.2 502.2, 524.2, 551 502.2, 524.2 502.2, 524.2 ±20% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ±20/40% ------- SYNTHETIC ORGANIC CONTAMINANTS PARAMETER REGULATED Alachlor* Atrazine1 Carbofuran1 Chlordane1 2,4-D* Dalapon2 Dibromochloropropane1 Dinoseb2 Diquat2 Endothall1 Endrin1 Ethylenedibroniide(EDB)1 Glyphosate1 Heptachlor3 Heptachlor epoxide1 Lindane* Methoxychlor1 Oxamyl* (Vydate) PentachlorophenoP Picloram1 Siniaziue2 Toxaphene1 2,4,5-TP(Savex)J Hexachlorobenzene* Hexachlorocyclopeutadiene1 Benzo(a)pyrene2 PCBs1 (as Aroclors) (as decachlorobipbenyl) 2,3,7,8-TCDD( Dioxin)1 Acrylauiide1 Epkhlorohydriii1 Di(2-etbylhexyl)adipate2 Di(2-ethylhexyl)phthalateI MCL/ [SMCL]10 mg/L 0.002 0.003 0.04 0.002 0.07 0.2 0.0002 0.007 0.02 0.1 0.002 0.00005 0.7 0.0004 0.0002 0.0002 0.04 0.2 0.001 0.5 0.004 0.003 0.05 0.001 0.05 0.0002 0.0005 3x10* Treatment Treatment 0.4 0.006 MCLG" mg/L zero 0.003 0.04 zero 0.07 0.2 zero 0.007 0.02 0.1 0.002 zero 0.7 zero zero 0.0002 0.04 0.2 zero 0.5 0.004 zero 0.05 zero 0.05 zero zero zero zero zero 0.4 zero METHODS5-7 ACCEPTANCE LIMITS" 505, 507, 508.1, 525.2 505, 507, 508.1, 525 J 531.1, 6610 505, 508, 508.1, 525.2 515.1, 515.2, 555 515.1, 552.1 504.1, 551 515.1, 515.2, 555 549.1 548.1 505, 508, 508.1, 525.2 504.1, 551 547, 6651 505, 508, 508.1, 525.2 505, 508, 508.1, 525.2 505, 508, 508.1, 525.2 505, 508, 508.1, 525.2 531.1. 6610 515.1, 515.2, 525.2, 555 515.1, 515.2, 555 505, 507, 508.1, 525.2 505, 508, 525.2 515.1, 515.2, 555 505, 508, 508.1, 525.2 505, 508, 508.1, 525.2 550, 550.1, 525.2 505, 508 508A 1613 506, 525.2 506, 525.2 ±45% ±45% ±45% ±45% ±50% 2SD ±40% 2SD 2SD 2SD ±30% ±40% 2SD ±45% ±45% ±45% ±45% 2SD ±50% 2SD 2SD ±45% ±50% 2SD 2SD 2SD 0-200% 2SD 2SD 2SD ------- METALS PARAMETER REGULATED Aluminum' Antimony1 Arsenic Barium1 Beryllium1 Cadmium1 Calcium Chromium1 Copper4'1 Iron1 Lead4 Manganese1 Mercury1 Nickel1 Selenium1 Silica4 Silver1 Sodium Thallium1 Zinc1 MCL/ [SMCL]10 mg/L [0.05-0.2] 0.006 0.05 2 0.004 0.005 - 0.1 1.3/90%4 [1.0] [0.3] 0.015/90%4 [0.05] 0.002 MCLG10 mg/L - 0.006 - 2 0.004 0.005 - 0.1 1.3 - zero - 0.002 Remanded14 0.05 - [0.1] 20'° 0.002 [5.0] 0.05 - - 0.0005 - METHODS57 ACCEPTANCE LIMITS" 200.7,200.8,200.9,31208,31138,31110 200.8, 200.9, D-3697-92, 3113-B 200.7, 200.8, 200.9, D-2972-93C, 3120B, 3113B, 3114B, D-2972-93B 200.7, 200.8, 3120B, 3111D, 3113B 200.7, 200.8, 200.9, D-3645-93B, 3120B, 3113B 200.7,200.8,200.9,31138 200.7, D511-93A, D511-93B, 3500-Ca-D, 3111B, 3120B 200.7, 200.8, 200.9, 3120B, 3113B 200.7, 200.8, 200.9, D1688-90C, D1688-90A, 3113B, 3111B, 3120B 200.7, 200.9, 3120B, 3111B, 3113B 200.8, 200.9, D3559-90D, 3113B 200.7,200.8,200.9,3120B,3113B,3111B 245.1,245.2,200.8,03223-91,31128 200.7,200.8,200.9,31208,31118,31138 200.8, 200.9, D3859-93A, D3859-93B, 31148,31138 200.7, D859-88, 4500-Si-D,E,& F, 3120B, 1-1700-85, 1-2700-85 200.7, 200.8, 200.9, 3120B, 31118, 3113B, 1-3720-85 200.7, 311B 200.8, 200.9 200.7, 200.8, 3120B, 3111B ±15% ±15% ±15% ±20% ±15% ±10% ±30% ±30% ±15% ±20% ±30% a - This method table is a convenient reference only: for details see the rules 1 - Secondary Maximum Contaminant Level - non-enforceable federal guidelines for aesthetic quality 2 - Phase V Regulations - promulgated 7-17-92 3 - Phase II Regulations - promulgated 1-30-91 and 7 1-91 4 - Lead and Copper Rule - promulgated 6-7-91; lead and copper levels are Action Levels 5 - Secondary contaminants may be analyzed using the recommended methods; Primary, unregulated (monitoring only) and state discretionary contaminants must be analyzed using approved methods in laboratories certified by the States. 6 - Radionuclides Proposed Rule - 7-18-91 7 - For method references, see 59 ER 62456, December 5, 1994 and TM-hniral Nntre nn Drinking Wat^r Methods, EPA-600/R-94-173, October, 1994 8 - Surface Water Treatment Rule - promulgated 6-29-89 9 - Recommended level 10 - MCL=maximum contaminant level; SMCL=secondary maximum contaminant level; MCLG = maximum contaminant level goal 11 - see CFR 141 Jl(e)(6&7) 12 - Coliform Rule - promulgated 6-29-89 13 - PE Acceptance Limits for VOCs are ±20% at *N)Mg/L and ±40% at <10//g/L 14 - The MCL and MCLG for nickel were remanded by court order on 2-23-95. Monitoring and analytical requirements remain the same. ------- and wastewater method updates are more coordinated and promulgated faster. Future updates may include the following: the 19th edition of Standard Methods, the current ASTM Annual Book of Standards, a revised EPA organic methods manual, EPA membrane filter Method 1104 for coliforms, and the EPA radionuclide methods which were proposed on July 18, 1991 (56 FR 33123-33125). Q. The sample or extract holding times for some analytes differ depending on the method used. Examples of this are the extract holding times for endothall in Methods 548 and 548.1, and the sample holding times for heptachlor in Methods 505 and 525.2. What should I do? A. Use the holding time in the method of choice. Holding times may vary because of differences in the analytical method. For example, the hydrazine derivative formed with the Method 548 procedure is less stable than the methyl derivative measured in Method 548.1. Thus, Method 548.1 extracts may be held longer. The holding time for heptachlor in Method 525.2 is longer than in Method 505 because heptachlor is more stable using the sampling and preservation procedures in Method 525.2. Differences also can occur when methods that do not contain the same set of analytes are compared. These differences occur because holding times and sample collection procedures are routinely optimized for most or all of the analytes in the method rather than for a single analyte. Q. Does the change in section 9.3.3 of Method 524.2 (Tech Notes, p. 40) mean that the continuing calibration criteria for Method 502.2 are changed from ±20% to ±30%? A. No. The continuing calibration and laboratory fortified blank accuracy criteria for Method 502.2 remain at ±20%. Changes to the quality assurance and calibration sections of methods 502.2 and 524.2, were discussed in Tech Notes beginning on page 40. The requirements are listed in the table below. Quality Assurance & Calibration Requirements for Methods 502.2 and 524.2 Method 502.2 section 524.2 section IDC Accuracy ±20% 10.3.3 ±20% 9.3.3 ccc Accuracy ±20% 9.2.2 ±30% 10.3.5 LFB Accuracy ±20% 10.5 ±30% 9.6 CCC may equal LFB? Yes 9.2.2 & 10.5 Yes 10.3 & 9.6 FRB may be substituted for LRB? No 10.6 & 10.4 No 9.7 & 9.6 FRB required only if samples are positive? Yes 10.6 Yes 9.7 CCC every shift or 12 hours? Yes 9.2.2 Yes 10.3 IDC = initial demonstration of capability CCC = continuing calibration check LFB = laboratory fortified blank FRB = field reagent blank LRB = laboratory reagent blank For additional information or clarification on the 1994 Methods Rule, contact the Safe Drinking Water Hotline, 800 426-4791 or Richard Reding, 513 569-7946. ------- PCB Analyses and Compliance We have received many questions recently about monitoring for PCBs because this is the last period in the monitoring cycle to comply with this requirement. The following recommendations have been excerpted from a guidance memo from OGWDW to the EPA Regional certification officers. This guidance does not change the monitoring triggers in the regulation, but rather suggests optional procedures the states may adopt if they wish to lower their detection limits for Aroclors. A PCB-compliance sample should be analyzed first for Aroclors using Method 505 or 508. If an Aroclor is detected, then a duplicate sample must be analyzed by Method 508A and positive results must be quantified and reported as decachlorobiphenyl to determine compliance with the MCL for PCBs. Negative Aroclor results from Methods 505 and 508 should be reported as "not detected" along with the laboratory's detection limit for each Aroclor. Although a method detection limit, calculated according to 40 CFR 136 Appendix B1, is a useful benchmark for evaluating and comparing method sensitivity, it may not be an appropriate indicator of the level at which an Aroclor can be identified. We recommend that an Aroclor detection limit or U.S. EPA Method 8081 (SW846) offers two options for quantitation of PCBs. One option uses the total area of the chlorinated biphenyl peaks and the other option uses the response of 3-5 major peaks (with capillary columns, we would recommend 7-10 peaks). A major peak is defined as one whose height is at least 25 % of the height of the largest chlorinated biphenyl peak. Either of these options would be appropriate to use in the calculation of the MDL. pattern recognition level (PRL) be defined as the lowest level at which recognition of the Aroclor peak profile (pattern) is possible. A PRL should be determined for each of the seven Aroclors in both reagent and tap water. Document how the PRLs were determined. Because this recognition is subjective, the limits should be determined by the same person who analyzes the compliance samples or interprets the quality control and compliance data. The table below lists the concentrations of the Aroclors that are equivalent to 0.0005 mg/L of decachlorobiphenyl. If detection limits lower than those specified in the regulations are desired, we recommend Method 508 over Method 505, because the higher solvent to water ratio should increase the sensitivity of the Aroclor screen. Sensitivity may also be increased by concentrating the Method 508 extract to less than the usual 5-mL. The success of this technique may vary with the quality of water, because, although concentration may improve Aroclor sensitivity in a reagent water spike, it may not in a tap water sample because concentration would also increase interfering impurities that may be present in the extract. 10 ------- Aroclor 1016 1221 1232 1242 1248 1254 1260 Equivalency Factor* 1.92 2.63 2.17 1.92 1.67 1.52 1.39 Aroclor Concentration 0.00026 0.00019 0.00023 0.00026 0.00030 0.00033 0.00036 DCBP Concentration 0.0005 0.0005 0.0005 0.0005 0.0005 0.0005 0.0005 * based on the percent chlorination of the Aroclor compared to decachlorobiphenyl and assuming 100% conversion (see method 508A, table 1) Federal regulations require use of an Aroclor screening method, but omit the requirement that a laboratory be certified for Aroclor identification. In response to state requests for guidance on how to approve or certify a laboratory for Aroclor screening, we recommend provisional certification using six criteria. 1. We recommend that certified for Method 508 regulated contaminants analyses. Although we only laboratories or 505 for other conduct Aroclor recommend using Method 508 more than 505, Method 505 may be used if the laboratory can achieve the necessary detection limits or PRLs. 2. Because laboratories may subcontract Method 508A analyses, we note that provisional certification for Aroclors only does not require the laboratory to be certified for Method 508A. 3. Use only laboratories that achieve satisfactory Aroclor PRLs. It is important to observe the chromatogram produced at the laboratory's PRL to verify the laboratory can recognize the Aroclor at that level. 4. In the PCB compliance monitoring scheme, Method 505 or 508 is used for identification and detection but not quantitation of Aroclors; therefore, some quality control requirements in the methods are unnecessary for Aroclor screening. For example, a calibration curve that is verified daily for each Aroclor is not necessary for compliance monitoring. However, a matrix spike is appropriate because it is important to know that the Aroclors can be identified in the sample. 5. Because it is important to verify Aroclor detection limits regularly, we recommend daily analysis of a laboratory fortified blank of a different Aroclor at the PRLs each analytical day. This schedule verifies the detection limit for each Aroclor every seven analytical days. 6. The PCB PE sample provided by EMSL for decachlorobiphenyl by Method 508A may also be used for Aroclors by Method 508 or 505. We suggest the laboratory identify the Aroclor present using Method 508 or 505. After the PE study is complete, EMSL will provide the identity and true value of the Aroclor which was present in the PE. Questions or comments may be directed to your State or Regional certification officer or Mary Ann Feige at 513 569-7944. 11 ------- Upcoming Meetings WEF Annual Conference October 21-25, 1995, Miami Beach, FL 703 684-2400 APHA Annual Conference October 29-November 2, 1995, San Diego, CA 202 789-5600 AWWA Water Quality Technology Conference November 12-16, 1995, New Orleans, LA 303794-7711. United States Environmental Protection Agency Office of Ground Water and Drinking Water Cincinnati, OH 45268 Official Business Penalty for Private Use $300 EPA-814N95001 BULK RATE POSTAGE & FEES PAID EPA PERMIT No. G-35 ------- |