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HEADWORKS ANALYSES Tricks of the Trade

HEADWORKS ANALYSES Tricks of the Trade. “Unknown Pretreatment Coordinator”. HEADWORKS ANALYSES. Background Information. “Technically Based Local Limits”. Eleventh Commandment: “Thou Shalt Neither Covet Nor Steal Thy Neighbor’s Local Limits”

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HEADWORKS ANALYSES Tricks of the Trade

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  1. HEADWORKS ANALYSESTricks of the Trade “Unknown Pretreatment Coordinator”

  2. HEADWORKS ANALYSES Background Information

  3. “Technically Based Local Limits” • Eleventh Commandment: “Thou Shalt Neither Covet Nor Steal Thy Neighbor’s Local Limits” • Keep in mind the definition of “local” [site specific…YOUR site] • Local limits should support and accommodate the strengths and weaknesses of each POTW

  4. “EPA Guidance” Documents • December 1987 – Development and Implementation of Local Discharge Limitations Under the Pretreatment Program • August 2001 - EPA Local Limits Development Guidance [Draft] • Published in Final Version by End of Calendar Year 2003????

  5. HWA/Local Limits Process • Determine Pollutants of Concern • Collect and Analyze POC Data • Calculate AHLs for all POCs • Select Most Stringent AHL as MAHL • Determine MAIL • Allocate MAIL to Industrial Users

  6. HWA Data Used to: • Identify/confirm presence of pollutants • Determine Pollutants of Concern [POCs] • Determine current POTW loadings • Calculate % Removal Efficiencies • Determine site-specific inhibition values • Estimate loadings from IUs, domestic/ uncontrollable sources, etc.

  7. National Pollutants of Concern • EPA Identified 15 pollutants often found in POTW effluent and sludge • Assume all 15 to be POCs unless Approval Authority agrees otherwise • EPA recommends POTW screeningfor these 15 using data from: • POTW influent, effluent and sludge • Industrial User discharges

  8. National EPA POCs

  9. Actual Loading vs. MAHLsEPA Guidance • Local limits should be established where: • The average actual influent loading of a pollutant is >60% of the MAHL, or: • The maximum actual influent loading is >80% of the MAHL any time in the 12 month period preceeding the analysis • For BOD and TSS: The monthly average influent loading is >80% of design capacity any one month in the 12 months before the headworks analysis

  10. MAXIMUM ALLOWABLE HEADWORKS LOADING Removal Rate Math Formula Importance of Removal Rates

  11. REMOVAL RATE:Math Formula % Removal Rate [Efficiency] = Influent (mg/l) – Effluent (mg/l)* 100 Influent (mg/l)

  12. Calculate %Removal Rate If a POTW has an influent BOD of 234 mg/l and an effluent BOD of 4.2 mg/l, what is the %removal rate (efficiency)? 234 mg/l – 4.2 mg/l * 100 234 mg/l = 98.2%

  13. Importance of Removal Rate Values Same POTW: 15.0 mg/l NPDES BOD Limit 5.0 MGD Flow

  14. Importance of Removal Rate Values Same POTW: 0.002 mg/l Cadmium Limit 5.0 MGD Flow

  15. TODAY’S TRICKS HEADWORKS ANALYSIS SAMPLING HEADWORKS ANALYSIS ANALYSES DATA REVIEW and INTERPRETATION REMOVAL RATE DETERMINATION

  16. HEADWORKS ANALYSIS SAMPLING HWA Data vs. NPDES/DMR Data “Paired” Samples [Detention Time Calculation] Whole Effluent Toxicity

  17. HWA SAMPLING:HWA Data vs. NPDES Data • NPDES Monitoring: “Daily” [Mon-Fri] • Consider Using all NPDES Data for HWA • “Composite Times” of NPDES samples • If only effluent analysis is NPDES required, look at resources for doing influent, too • Don’t sample on same day of week for every HWA sample [You’ll see why later…] • Quarterly Sampling * 5 yrs = 20 data points

  18. HWA SAMPLING:Know When NOT to Sample • Hurricane or High Flow Conditions • POTW Upset • POTW Power Failure • Equipment Break-Down or PM • During POTW Upgrade/Expansion • Holidays [Week of Christmas/July 4th] • Don’t be so “compulsive” that you can’t be flexible with HWA sampling

  19. HWA SAMPLING:POTW Sampling Locations • POTW Influent* • Before mixing with any recycle streams • POTW Effluent* • Aerobic/Anaerobic Digester* • “Acclimation” values • Biosolids to Disposal* • 40 CFR Part 503 Annual Report Data • Activated Sludge • “Acclimation” values

  20. HWA SAMPLING:“Paired” Samples Sampling • “Pair” Influent/Effluent Samples According to Detention Time (DT) • “Delayed” Composite SamplersOR • IF DT is ~24 HOURS, or ~48 HOURS, or ~72 HOURS • Just Use Regular “Daily” Composite Results and “Match Them” [i.e. 24 hour DT… Monday’s influent is “paired” with Tuesday’s effluent]

  21. HWA SAMPLING:“Paired” Samples Sampling DETENTION TIME (DT) FORMULA: POTW Detention Time [in hours] = 24 [hr/day] * POTW Tank Volumes [MG] Actual POTW Flow [MGD]

  22. Calculate Detention Time • Tank Volumes [look in POTW O&M Manual] • Primary Clarifiers = .40 MG • Aeration Tanks = 1.40 MG • Final Clarifiers = 0.60 MG • Chlorine Contact Tank 0.105 MG • Permitted Flow = 4,000,000 gpd • Actual Flow = 2,250,000 gpd

  23. Calculate Detention Time [DT] TV = 0.4 + 1.4 + 0.6 + .105 = 2.505 MG Actual Flow = 2,250,000 gpd 1,000,000 gal/MG = 2.250 MGD DT = 24 (hr/day) * Tank Volume [MG] Actual Flow [MGD] DT = 24 (hr/day) * 2.505 MG 2.250 MGD = 26.72 hours

  24. Calculate RR for Paired and Unpaired Samples My POTW DT is 72 Hours….So what???? -56% 76% -33% 84% MAHL = 0 pounds Nickel MAHL = 19.8 pounds Nickel POTW Flow = 3.5 MGD NPDES Nickel Limit = 136 ug/l

  25. HWA SAMPLING:Whole Effluent Toxicity • Remember: TWO 24-Hour Composite Samples Used For WET [Bioassay] • Coordinate Quarterly HWA Analyses with Quarterly WET….. • Metals, Cyanide [Influent and Effluent] • Influent Analyses on all POC • Aeration Tank Samples for Inhibition, Too!!!

  26. HEADWORKS ANALYSIS ANALYSES Don’t Go Changin’….. Metals, Metals Everywhere Trick or Treat????

  27. HEADWORKS ANALYSES:“Don’t Go Changin’….” • Detection Limit (DL) a.k.a. Lower Reporting Level (LRL) a.k.a. Practical Quantitation Limit (PQL) • What does this mean in a Commercial/POTW Laboratory? • Trouble if you don’t understand what you need and want…….

  28. HEADWORKS ANALYSES:Metals, Metals Everywhere • “REGULAR LEVEL” METALS ANALYSES • Flame Atomic Absorption [AA] • ICP [“Plasma”] • “LOW LEVEL” METALS ANALYSES • Graphite Furnace Atomic Absorption • ICP/MS [Plasma Mass Spec]

  29. “Regular Level” Metals Removal Rate Example • Chromium Influent = 11 ug/l • Chromium Effluent = <10 ug/l • Some states will let you use ½ DL on the effluent value…….[10 * ½ = 5 ug/l] 11 – 5 * 100 11 = 54.5 % RR [OR Median Literature Value of 82%] VERSUS………….

  30. “Low Level” Metals Removal Rate Example • Same Exact HWA Samples analyzed by ICP-MS • Chromium Influent = 11 ug/l • Chromium Effluent = 0.70 ug/l 11 – 0.70 * 100 = 93.6% RR 11 [Oh what a difference ICP/MS makes!]

  31. SAME POTW…SAME SAMPLES…. 5.0 MGD Flow and 0.050 mg/l Effluent Limit

  32. Something Else to Consider… MAHL = 1516 pounds NH3N MAHL = 7784 pounds NH3N POTW Flow = 3.5 MGD NPDES NH3-N Limit = 2.0 mg/l

  33. HEADWORKS ANALYSES:Mercury“Trick or Treat”? • MERCURY [Look out!!!] • Oregon Hg Stream Standard = 0.012 ug/l [12 ng/l] • Many States previously had NPDES Permits with that limit and a 0.2 ug/l Quantitation Level Statement • <0.2 ug/l was considered “compliant” • Cold Vapor AA LRL = 0.2 ug/l [200 ng/l] • Method 1631 LRL = 0.001 ug/l [1 ng/l] • Clean Metals Sampling is a MUST! • Very few laboratories can perform this method • Much more expensive

  34. HEADWORKS ANALYSES:Cyanide“Trick or Treat”? • CYANIDE TRICKS • You Can’t Teach an Old Method New Tricks…[at 5 ug/l] • Split Samples and Matrix Spikes • Before and After Chlorination • Drinking Water • Can a Hot Dog Manufacturer Really Have CN??? [Call the FDA!!!] • What are the Odds????

  35. DATA REVIEW and INTERPRETATION HWA Data Review Signs/Causes of Trouble in Laboratory Land What Would You Do with this Mess?

  36. HWA DATA REVIEW • Review HWA Monitoring Plan Data • Is the HWA Data Valid? Does it Make Sense? • Is the Pollutant Present in the Influent? • If not, can it be an internal POTW process? • Is the POTW….Compliant? Noncompliant? • Look at historical removal efficiencies • How do they compare with what YOU got? • Audit Laboratory [POTW and Commercial]

  37. REVIEW HWA/HWA DATA ASAP • HWA Cyanide Data “Town X” • 22 Effluent CN Analyses in past 5 years • 18 DP <5 ug/l, 3 DP at 5 ug/l, 1 DP at 157 ug/l** • No Electroplating or Metal Finishing Facilities • HWA Data-Same Date** • Influent CN = 6.1 ug/l • Primary Effluent CN = <5 ug/l • Effluent CN = 157 ug/l • You’re in trouble if you haven’t even looked at the data until time to do HWA

  38. SIGNS OF TROUBLE IN LABORATORY LAND…... • “Double” Numbers • Negative removal rates (maybe…) • Lots of Greater Than (>) Values • Metals, Metals Everywhere??? • TKN vs. Ammonia and NO2 vs. NO3 • COD vs. BOD • What are the odds???

  39. CAUSES OF TROUBLE IN LABORATORY LAND…... • Calculations [units conversions, decimals] • Sample “Mix-Up” [tough to trace] • Omission [a preservative, a step, a reagent, BOD seed, pH adjustment] • Holding Time Exceedance • Spill and Breakage • Contamination

  40. TROUBLESHOOTING:Correct Units mg/l = ppm [milligrams per liter = parts per million] µg/l = ppb [micrograms per liter = parts per billion] ng/l = ppt [nanograms per liter = parts per trillion] *Oregon Mercury Stream Standard [chronic]

  41. “The Troubles You’ll See…” Biosolids Analyses *Calculation Error-Actual Value was 11.1 mg/kg Note: 40 CFR Part 503 Ceiling Value is 75 mg/kg

  42. WHAT WOULD YOU DO WITH THIS MESS??? Actual STMP Ammonia Values*: *From Commercial Laboratory, not POTW Laboratory

  43. WHAT WOULD YOU DO WITH THIS MESS??? [#2] Actual STMP BOD Values*: *From Commercial Laboratory, not POTW Laboratory

  44. REMOVAL RATE DETERMINATION EPA Local Limits Guidance Literature Values POTW Site-Specific Data Methods Review Data Set

  45. Literature Removal Rates**Median and 8th Decile Values Activated Sludge Treatment ** EPA Local Limits Development Guidance-Draft 8/2001

  46. EPA Literature Values • Avoid Them Like the Plague • Generate Site Specific Data • Based on POTW data from 1977! • 2001 LL Guidance Draft Contains Same “Outdated” Data • The Most Conservative Value Chosen in Every Case for Inhibition • Domestic Values “High” in most cases

  47. REMOVAL RATES:POTW Site-Specific Data • Average Daily Removal Efficiency [ADRE] • Mean Removal Efficiency [MRE] • Deciles

  48. POTW Site-Specific RR:Avg. Daily Removal Efficiency • Calculate daily removal efficiency [DRE] (removal rate) for each day you have influent and effluent data….and the influent value was “detectable” • Average all the resulting DREs • Can be used with “paired” or unpaired data [EPA recommends paired]

  49. CalculateADRE - BOD 0.0% 98.86% 99.22% 99.04% 74.28% 99.04%

  50. POTW Site-Specific RR:Mean Removal Efficiency [MRE] • Determine average of ALL influent values • Determine average of ALL effluent values • You may be able to use ½ DL for BDL • Calculate removal efficiency using these two numbers • Can be used with paired or unpaired samples

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