1. EPA REGION VI MINIMUM QUANTIFICATION LEVELS (MQLs) WHAT THE “L” IS GOING ON? 25 th EPA Annual Pretreatment Workshop Addison, TX 8/5/09 Allen Gilliam ADEQ State Pretreatment Coordinator gilliam@adeq.state.ar.us

2. REGION 6’s FIRST “WARNING” 4/10/06 EPA Region 6 “Claudia Hosch Memo” (“for review and comment”)  “In 1992 Region 6 developed guidance on the use of MQLs and how they would be used in the NPDES permit decision making progress”  “…labs have made advancements in quantification levels thru method enhancements and EPA approved test methods have become more commonly available.”  “In a number of cases, the new MQL values are now below WQ criteria which were previously unattainable.”  “Most of our states have incorporated these MQL values into their permitting procedures…”

3. Some Proposed Minimum Quantification Levels (MQLs)

4. 8/23/07 - “Hanlon Memo” (EPA HQs) discussing Mercury compliance with Water Quality Standards to Regions 8/23/07 - “Hanlon Memo” (EPA HQs) discussing Mercury compliance with Water Quality Standards to Regions “This memorandum clarifies and explains that, in light of existing regulatory requirements for NPDES permitting, only the most sensitive methods such as Methods 1631E and 245.7 are appropriate in most instances for use in deciding whether to set a permit limitation for Hg and for sampling and analysis of Hg pursuant to the monitoring requirements within a permit.”

5. “Hanlon Memo” discussing compliance with WQ Standards (cont.) “For [delegated] States, EPA Regions…should strongly consider objecting to permits that are issued based on analytical data that is collected and analyzed using an EPA approved method not sufficiently sensitive or that do not require use of a sufficiently sensitive EPA approved method for monitoring…”

6. Region 6 / States WQ Managers’ “Love-In” meeting excerpts (10/30/07)  MDL – Method Detection Level –minimum concentration of a substance that can be measured and reported with 99% confidence that the analyte concentration is > 0 and is determined from analysis of a sample in a given matrix containing the analyte  LOD – Limit of Detection – – approximately 3 times the standard deviation obtained from replicate measurements and may be described as that value determined to be statistically significant from the measurement of a reagent blank

7. Region 6 / States’ WQ Managers’ “Love- In” meeting notes (10/30/07 cont.)   LOQ – Limit of Quantitaion – –attempts to define a level of analyte that may be repeatedly measured   Region 6 has elected to define MQL as the lowest concentration at which a particular substance can be quantitatively measured – –LOD = 3 standard deviations – –LOQ = 10 standard deviations – –LOQ = 10/3 LOD – –LOD = MDL ??? – –MQL = 3.3 MDL

8. Some Final Region 6 MQLs October 30, 2007 “Existing”Revised ParameterMQL MQL ParameterMQL  g/l MQL  g/l Aluminum1002.5 Arsenic 100.5 Beryllium 50.5 Copper 100.5 Lead 50.5 (Method) Mercury 0.20.0005 / 0.005 (1631E / 245.7) Nickel 400.5 Selenium 55 Silver 20.5 Thallium 100.5 Cyanide 2010

9. WHAT DO THESE MQLs MEAN TO YOU?  Do you know your state’s permitting procedures (should be part of your “Continuing Planning Process” document req’d by 40 CFR 130.5)?  States’ procedures in Region 6 are somewhat similar  NPDES renewal? Majors must analyze / report results from a Priority Pollutant Scan (PPS) – One sampling event / 5 years

10. PERMITTING PROCEDURES One Sample (Hg for example) 1. Calculate “reasonable potential” to exceed WQ standard Hg Water Quality Standard = 0.012 Hg Water Quality Standard = 0.012  g/l Priority Pollutant Scan result X 2.13 (EPA’s statistical multiplier from their “Technical Support Document for WQ-based Toxics Control”. Arguable…) PPS Hg result = 0.006 PPS Hg result = 0.006  g/l 0.006 ug/l X 2.13 = 0.0128 0.006 ug/l X 2.13 = 0.0128  g/l) 2. Reasonable potential? 0.0128 > 0.012 ? 2. Reasonable potential? 0.0128 > 0.012  g/l ? YES, Hg limit will be incorporated into permit.

11. ARKANSAS WORST CASE “WQ LEVELS NOT TO EXCEED” 7Q10 = 0 CFS (Intermittent Stream) Pollutant Monthly Avg. (g/l) Monthly Avg. (  g/l)MQL (g/l) (  g/l) Arsenic3350.5 Beryllium 5.91 5.910.5 Copper 8.7 8.70.5 Lead 2.6 2.60.5 Mercury 0.012 0.0120.005 Nickel 90 900.5 Selenium 5.6 5.6 5 Silver 0.94 0.940.5 Cyanide 6.0 6.0 10 10

12. EXTRA “SCRUTINY” FOR THE PRETREATMENT CITIES?  Region 6 Pretreatment Cities required to do quarterly influent / effluent monitoring, maybe more? –Hopefully, you’re using the most sensitive methods for both (for most valid site specific removal efficiencies)  More data points for NPDES permit writer to use in calculating “reasonable potential”! –PLEASE use common sense clean sampling techniques

13. MONITORING RESULTS FOR THE ANNUAL PRETREATMENT REPORT REPORTING YEAR: __________, 20 TO __________, _20____ TREATMENT PLANT: City of ____ NPDES PERMIT #AR00____ _____ AVERAGE POTW FLOW: MGD % IU FLOW: % METALS, CYANIDE and PHENOLS MAHC (Total) (g/l) (  g/l) INFLUENT DATES SAMPLED (  g/l) Once/quarter WQ level/ limit (  g/l) EFFLUENT DATES SAMPLED (  g/l) Once/quarter LAB ANALYSIS EPA MQL (  g/l) EPA Method Used Detection Level Achieved (  g/l) Date Cadmium 1.920.5 Copper 8.70.5 Lead 2.60.5 Mercury 0.012.005 Selenium 5.65 Silver 0.940.5 Cyanide 5.810 Arsenic 3350.5

14. PERMITTING PROCEDURES FOR LIMITED DATA SETS (<20) 1.Permit writer takes data points: 2.Calculates geometric mean (GM) a. GM = [ (X 1 )(X 2 )(X 3 )........(X N ) ] 1/N ; 3.Multiplies GM X 2.13 to determine “reasonable potential”; 4.If reasonable potential exists  Permittee gets permit limit

15. MONITORING RESULTS FOR THE ANNUAL PRETREATMENT REPORT REPORTING YEAR: __________, 20 TO __________, _20____ TREATMENT PLANT: City of ____ NPDES PERMIT #AR00____ _____ AVERAGE POTW FLOW: MGD % IU FLOW: % METALS, CYANIDE and PHENOLS MAHC (Total) (  g/l) INFLUENT DATES SAMPLED (  g/l) Once/quarter WQ level/ limit (  g/l) EFFLUENT DATES SAMPLED (  g/l) Once/quarter LAB ANALYSIS EPA MQL (  g/l) EPA Method Used Detection Level Achieved (  g/l) Date 2/085/088/0811/08 Cadmium1.920.5 Copper8.70.5 Lead2.60.5 Mercury0.0120.0280.0070.0160.046.0051631E0.0005 Selenium5.65 Silver0.940.5 Cyanide5.810 Arsenic3350.5

16. PERMITTING PROCEDURES FOR LIMITED DATA SETS (<20) for Hg 1.Permit writer takes data points: 2.Calculates geometric mean (GM) a.GM = [ (.026)(.007)(.016)(.046) ] 1/4 = 0.018 a.GM = [ (.026)(.007)(.016)(.046) ] 1/4 = 0.018 (  g/l) b.Don’t even have to calculate “reasonable potential” 3.WQ “level not to exceed” = 0.012 3.WQ “level not to exceed” = 0.012 (  g/l) 4.Reasonable potential definitely exists  Permittee gets permit Hg limit

17. MONITORING RESULTS FOR THE ANNUAL PRETREATMENT REPORT REPORTING YEAR: __________, 20 TO __________, _20____ TREATMENT PLANT: City of ____ NPDES PERMIT #AR00____ _____ AVERAGE POTW FLOW: MGD % IU FLOW: % METALS, CYANIDE and PHENOLS MAHC (Total) (  g/l) INFLUENT DATES SAMPLED (  g/l) Once/quarter WQ level/ limit (  g/l) EFFLUENT DATES SAMPLED (  g/l) Once/quarter LAB ANALYSIS EPA MQL (  g/l) EPA Method Used Detection Level Achieved (  g/l) Date 2/085/088/0811/08 Cadmium1.920.5 Copper8.7<0.5<0.510120.5200.80.5 Lead2.60.5 Mercury0.012.005 Selenium5.65 Silver0.940.5 Cyanide5.810 Arsenic3350.5

18. PERMITTING PROCEDURES FOR LIMITED DATA SETS (<20) for Cu 1.Permit writer takes data points (if there’s even one detect, “NDs” are treated as ½ MQL) : 2.Calculates geometric mean (GM) a.GM = [ (.25)(.25)(10)(12) ] 1/4 = 1.65 a.GM = [ (.25)(.25)(10)(12) ] 1/4 = 1.65  g/l 3.GM X 2.13 to determine “reasonable potential” = 1.65 X 2.13 = 3.5 3.GM X 2.13 to determine “reasonable potential” = 1.65 X 2.13 = 3.5  g/l 4.WQ “level not to exceed” = 8.7 4.WQ “level not to exceed” = 8.7  g/l 5.Reasonable potential does not exist  Permittee gets no Cu limit

19. MONITORING RESULTS FOR THE ANNUAL PRETREATMENT REPORT REPORTING YEAR: __________, 20 TO __________, _20____ TREATMENT PLANT: City of ____ NPDES PERMIT #AR00____ _____ AVERAGE POTW FLOW: MGD % IU FLOW: % METALS, CYANIDE and PHENOLS MAHC (Total) (  g/l) INFLUENT DATES SAMPLED (ug/l) Once/quarter WQ level/ limit (  g/l) EFFLUENT DATES SAMPLED (ug/l) Once/quarter LAB ANALYSIS EPA MQL (  g/l) EPA Method Used Detection Level Achieved (  g/l) Date 2/085/088/0811/08 Cadmium 1.920.5 Copper 8.70.5 Lead 2.60.5 Mercury 0.012.005 Selenium 5.65 Silver 0.940.5 Cyanide 5.8<107<108.0510330.55 Arsenic 3350.5 YOUR WORST NIGHTMARE!

20. PERMITTING PROCEDURES FOR LIMITED DATA SETS (<20) for CN 1.Permit writer takes data points (if there’s even one detect, “NDs” are treated as ½ MQL) : 2.Calculates geometric mean (GM) a.GM = [ (5)(7)(5)(8.05) ] 1/4 = 6.13 a.GM = [ (5)(7)(5)(8.05) ] 1/4 = 6.13  g/l b.Don’t even have to calculate “reasonable potential” 3.WQ “level not to exceed” = 5.8 Reasonable potential exists  Permittee gets CN limit 3.WQ “level not to exceed” = 5.8  g/l Reasonable potential exists  Permittee gets CN limit

21. MONITORING RESULTS FOR THE ANNUAL PRETREATMENT REPORT REPORTING YEAR: __________, 20 TO __________, _20____ TREATMENT PLANT: City of ____ NPDES PERMIT #AR00____ _____ AVERAGE POTW FLOW: MGD % IU FLOW: % METALS, CYANIDE and PHENOLS MAHC (Total) (  g/l) INFLUENT DATES SAMPLED (  g/l) Once/quarter WQ level/ limit (  g/l) EFFLUENT DATES SAMPLED (  g/l) Once/quarter LAB ANALYSIS EPA MQL (  g/l) EPA Method Used Detection Level Achieved (  g/l) Date 2/085/088/0811/08 Cadmium1.920.5 Copper8.70.5 Lead2.60.5 Mercury0.012.005 Selenium5.6<10<10<10<10 5200.82 Silver0.940.5 Cyanide5.810 Arsenic3350.5 NEED LAB EXPLANATION ON THIS ONE!

22. PERMITTING PROCEDURES FOR LIMITED DATA SETS (<20) for CN 1.Permit writer takes data points (if the “NDs” > the MQL, values will be entered at the MQL) : 2.Calculates geometric mean (GM) a.GM = [ (10)10)(10)(10) ] 1/4 = 10 a.GM = [ (10)10)(10)(10) ] 1/4 = 10  g/l b.Don’t even have to calculate “reasonable potential” 3.WQ “level not to exceed” = 5.6 Reasonable potential exists  Permittee gets Se limit 3.WQ “level not to exceed” = 5.6  g/l Reasonable potential exists  Permittee gets Se limit

23. What the “L” is going on with this logic?  Do not sample effluent after a rain event or when your plant is suspected of being “upset”  Require your labs to explain why they could not meet the required MQL (“had to dilute because of matrix condition being turbid or suspected of containing matrix interferences….”)  Note to your permit writer: “results should not be used in calculating ‘reasonable potential’ because they were not representative”  Contest / ask permit writer about the rationale behind the “reasonable potential” multiplier of 2.13 (if your state uses it)