Mercury Method 1631: Its Not As Bad As We Thought It Would Be

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Mercury Method 1631Its Not As Bad As We
Thought It Would Be

• Dana Folley, PERCS Unit
• 2005 NC Pretreatment Workshop
• August 23, 2005
• Charlotte, NC

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Mercury Sources

• Natural Sources - volcanoes, forest fires, soils
• Manmade Sources - coal-fired power plants,
  incinerators, manufacturing, dental amalgam
• WWTP
• sewer pipe slime bio-accumulates Hg, releases Hg
  when slime sloughs off
• Sediments accumulate Hg, heavy flow sends Hg to
  WWTP
• WWTP equipment with mercury bearings, switches
  - seals fail
• Mercury crosses state, regional, global boundaries

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Minamata DiseaseJapan 1956
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EPA Saves Snowball in Vegas (2004)!
Waynesville 10/04 1/2 cup Hg spilled, cleaning
lady to hospital, house decontaminated
Asheboro 2005 resident collects periodic
table elements, incl. 39 lbs Hg, plus!
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North Carolina Fish Consumption Advice

• Issued in April 2002
• Advises restricted consumption of largemouth
  bass, chain pickerel, bowfin caught from NC
  waters
• Establishes range of south and east of I-85

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Water Bodies on 303(d) List for Mercury

• 303(d) list to EPA of impaired NC waters -based
  on actual fish tissue analysis
• Entire Lumber River Basin
• Roanoke River
• Parts of Neuse River main stem (NEW)
• Albemarle Sound
• Atlantic Ocean - for King Mackerel only
• 7 other creeks, rivers, and lakes in the Cape
  Fear, Roanoke, Pasquotank, White Oak and Yadkin
  Basins

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Water Quality Standards - Water

• NC WQS
• Aquatic Life (Freshwater chronic) 12 ng/l
  (0.012 ug/l)
• Aquatic Life (Saltwater chronic) 25 ng/l
• Great Lakes WQS
• Human Health 1.8 ng/l
• Wildlife 1.3 ng/l
• EPA Criteria
• Aquatic Life (Freshwater acute) 1,400 ng/l
• Aquatic Life (Freshwater chronic) 770 ng/l
• Drinking Water Standard - 2,000 ng/l
• NC Groundwater WQS 1,100 ng/l

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Water Quality Criteria- Fish Tissue

• EPA Human Health Criterion
• 0.3 mg Methyl Hg/kg fish
• NC DHHS Fish Advisory
• 0.4 mg Total-Hg/kg fish
• Compare to Japan 1956 Minamata Exposure
• Residents consumed fish with 20 mg methyl mercury
  per kg of fish during several meals per week for
  years
• How to convert fish tissue criteria to water
  column criteria?

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EPA Method 1631- Why use it?Detection Level !!
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EPA Method 1669- Clean Sampling
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NC Method 1631 Requirements

• Based on EPA agreement, DWQ required Method 1631
  for effluent sampling at applicable NPDES
  facilities beginning September 1, 2003.
• Current or potential NPDES limit is 200 ng/l or
  below (see mercury limit calculator on PERCS
  mercury webpage)
• And
• Mercury is pollutant of concern (on NPDES limits
  page, pretreatment program, or major municipal)

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Method DMR Effluent 1631 Results

• See Chart
• 92 effluent samples below WQS 12 ng/l
• Why such good results?
• Clean sampling, pretreatment, pollutant removal,
  etc.
• Its not as bad as we thought it would be!

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NC Mercury NPDES Permitting Requirements

• Mercury limit will now be expressed as Weekly
  Average for renewals/new/mods.
• Class III and IV WWTPs - Weekly effluent
• Class I and II WWTPs -Twice per month effluent
• For new limits, compliance schedule available to
  allow for source evaluation, budgeting, etc.
• Its not as bad as we thought it would be!

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NC NPDES Permitting for Non-Impaired Waters

• WWTP Receiving Waterbody is not Hg-impaired i.e,
  not on 303(d) list
• Calculate NPDES limit in normal fashion,taking
  into account upstream dilution at 10 year drought
  stream flow (7Q10)
• Perform normal Reasonable Potential Analysis
  (RPA) with 7Q10 dilution
• If reasonable potential exists for WWTP to
  violate limit, add limit and possible Compliance
  Schedule

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NC NPDES Permitting for Hg-Impaired Waters

• WWTP Receiving Waterbody is Hg-impaired and on
  303(d) list
• EPA assumes upstream already at NC WQS, so do not
  allow 7Q10 dilution credit
• NPDES limit will be equal to NCWQS 12 ng/l
• Perform Reasonable Potential Analysis (RPA) with
  NO dilution credit
• If reasonable potential exists for WWTP to
  violate limit, add limit and possible Compliance
  Schedule
• Facility can collect upstream samples to test
  assumption.

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NC NPDES Permitting for Hg-Impaired Waters with
TMDLs

• Current TMDLs (Lumber, Cashie) have shown point
  sources to be minimal contributor to mercury
  load.
• TMDL can be expressed in NPDES permits as a mass
  load limit (eg. grams/day) or require
  implementation of a Pollution Prevention (P2)
  strategy.
• PERCS and Division of Pollution Prevention and
  Environmental Assistance (DPPEA) currently
  preparing P2 language.

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NC NPDES Compliance

• For those with limits already, generic SOC with
  P2 requirement is being developed for any
  non-compliant facilities.
• Regions continue with civil penalty discretion.
• Its not as bad as we thought it would be!

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NC NPDES Discharge Monitoring Reports (DMRs)

• Enter mercury data in same units as are on NPDES
  limits page.
• Enter all effluent mercury data, even LTMP/STMP.

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NPDES Compliance - Pretreatment

• Remember MSDSs dont tell you about inactive
  ingredients or contaminants.
• What if mercury is in ambient or raw water
  supplies?
• Drinking Water Standard - 2,000 ng/l
• NC Groundwater WQS 1,100 ng/l
• If Mercury is everywhere, what good will slapping
  zero limits on a few big bad SIUs do?
• Dentists!!!!!!

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Method 1631 and Pretreatment Requirements

• NC DWQ PERCS will only require 1631 for other
  locations (Influent, Uncontrollable, SIU, etc.)
  if there is a problem at your effluent, i.e., you
  are having significant limits violations
• December 18, 2002 Memo _at_ PERCS webpage

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Method 1631 and Pretreatment

• Of the few Pretreatment POTWs that were having
  detections above 200 ng/l using 245.1, most are
  NOT having any hits any where near 200 ng/l with
  1631 and 1669!
• 24 HWAs using 1631 for effluent
• 9 of these also using 1631 influent
• 18 approved, 6 more in house

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Method 1631 in Pretreatment HWAs

• avg of avgs range of avgs
• Influent 224 27.7 - 430
• Only 1631 189
• Only 245.1 244
• Effluent 6.06 0.68 - 35
• Max individual effluent 102.4

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Method 1631 in Pretreatment HWAs

• average range
• Removal Rate 96 87 - 99
• MAHL triples or quadruples over MAHL using EPA
  Literature Removal Rate of 60
• 5 without tertiary filters need more HWAs to
  verify if are differences
• Its better than we thought it would be!!!

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Method 1631 in Pretreatment HWAs

• Uncontrollable avg of avgs range of avgs
• Sampling 212 100 - 510
• Mass balance 228 71 470
• Not that different from EPA Literature of 300

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NC Water Quality Standard (WSQ)

• Current NC WQS adopted in 1989 based on EPAs
  1988 Water Quality Criteria
• EPAs new (January 2001) Ambient Water Quality
  Criteria (WQC) is expressed as 0.3 mg/kg methyl
  mercury in fish tissue
• Need Bio-accumulation Factors (BAFs) to translate
  this EPA WQC into total mercury surface water
  quality target/standard
• EPA Guidance on this still not out

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NC Eastern Regional Mercury Study (ERMS)

• Gather NC specific stream and fish tissue data
  needed to calculate BAFs and perform translation
• Implemented Nov 2002-Aug 2003
• Final Report on web-site next year
• Mercury Study Extension covers the French Broad
  to the Pasquotank

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ERMS Target water column levels to protect human
health (fish consumption)
Goal 3a Target water levels
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DWQ Water Quality Standard

• With Method 1631, NC Mercury WQS exceeded in
  surface waters in some cases.
• Appears existing WQS not protective of
  consumption of largemouth bass except for smaller
  fish, and even then not in all cases.
• Although recommended by EPA, BAF approach assumes
  relationship between mercury fish tissue and
  mercury (or methyl mercury) in water column is
  linear. This may not be true.
• Need EPA WQC Implementation Guidance

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And now for the big picture
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Mercury Questions?

• All emails are firstname.lastname_at_ncmail.net
• PERCS - Pretreatment Dana Folley, NC DWQ, PERCS
  Unit [phone] ext. 523
• http//h2o.enr.state.nc.us/Pretreat/Mercury/mercur
  y.html
• NC DWQ Mercury 1631 letters NPDES - 8/30/02 and
  8/1303 Pretreatment 12/18/02
• Mercury NPDES limit calculator
• Method 1631 and 1669 (clean sampling) documents
• Presentations, guidance, and links

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Mercury Questions?

• NPDES Tom Belnick, NC DWQ, Point Source Branch
  [phone] ext. 543
• http//h2o.enr.state.nc.us/NPDES/index.html
• NC DWQ Laboratory [phone]
• Metals Unit
• Roy Byrd, Lead Chemist, ext 213
• http//h2o.enr.state.nc.us/lab/mib.htm
• DWQ 1631 lab up and running!!!
• Laboratory Certification Unit
• James Meyer, Supervisor, ext. 207
• http//h2o.enr.state.nc.us/lab/cert.htm

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Mercury Questions?

• ERMS/TMDL/303(D) List Michelle Woolfolk, NC DWQ,
  ModelingTMDL Unit [phone] ext. 505
• http//h2o.enr.state.nc.us/tmdl/
• WQS Connie Brower, NC DWQ Standards Unit(919)
  733-5083 ext. 380,
• http//h2o.enr.state.nc.us/csu/index.html
• Fish Advisories Luanne Williams, NC Dept Health
  and Human Services [phone]

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Mercury Questions?

• Biological Assessment (Fish tissue)
• Mark Hale, http//h2o.enr.state.nc.us/esb/BAU.html
  
• Planning - Basinwide Plans
• http//h2o.enr.state.nc.us/basinwide/
• Ambient Coalition Monitoring
• http//h2o.enr.state.nc.us/esb/EU.html

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Mercury - Summary

• Mercury can be bad in the environment and to
  human health, especially as Methyl mercury
• Incidents of Mercury Contamination are still
  occurring
• Some NC waters have fish exceeding health
  criteria, DHSS issued fish consumption advice
  notices for half of NC

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Mercury Summary (continued)

• Most NC NPDES facilities below NC WQS
• Can get P2 SOCs if significant violations
• NPDES Civil Penalty Discretion Continues
• New/Renewal NPDES Limits - weekly avg
• New NPDES Limits can include compliance schedule
• TMDL Limits may be expressed as P2 schedules

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Mercury Summary (continued)

• Method 1631 works well on WWTP influent,
  uncontrollable, and SIUs
• WWTP site-specific 1631 removal rates much higher
  than EPA Literature
• Site-specific 1631 Uncontrollable within range of
  EPA literature
• DWQ PERCS may adopt NC literature Hg removal rate
  and uncontrollable values

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Mercury Summary (continued)

• DWQ continues to study NC site-specific mercury
  water body conditions and basis for NC WQS

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Questions?