NC0025445_CORRESPONDENCE_20030812

OF W ATFR
w co O Y
David B Cotton
Cin of Ralcllcman
101 I lillary Street
Randleman, NC 27317
Dear NPDLS Permitted
Michael F Easley Governor
Willi im G Ross Jr Secretary
North Carolina Department of Environment and Natural Resources
Alan W Klimek P E Director
Division of Water Quality
August 12, 2003
Subject NPDLS Pcrmit NCO025445 LMercUr% Requirement
LPA Method 1631 / Additional Information
Ctn of Randleman WW 1 P
Randolph County
In a previous letter dated August 30 2002, 1oui facilml wis notified of bung subject to a new low-level mercury
analysts (I"PA Method 1631) for NPDLS monitoring requtrcmcnts beginning September 1, 2003 1 he notification
letter was marled to 155 sublect facilities Since that milling, the Division has participated in schcral Dletcury 1631
Workshops to provide the rcgulatcd eommumn with information on the new anahtical requirements and dean
s umphng recommend ttions B ised on comments received at then workshops, the following items arc intended to
clarify certain NPDLS requirements for the 155 subject facilities
1 Mercury Sampling and Compliance It is recommended that f tuhnes collect some. cfflucnt samples for Method
1631 analysts prior to the 9/1/2003 effective dart, in order to gain espu.rience with the recommended clean
sampling techniques as well as the anahsis requirements NPDLS compliance will be judged using the new
method results beginning 9/ 1 /2003
2 What Samples are Subject to Method 1631 Beginning 9/l/2003, all effluent samples collected for mercury
from the subject faaht) are required to perform low level mercur) anahsis This includes effluent samples
collected for any of the following requirements a) monitoring specrficd in your "Pfflucnt Limitations and
Monitoring Requirements" page of your NPDLS permit, b) monitoring specified in hour NPDLS Pretreatment
Short Perm Monitoring Plan (SIMP) or Long Term Monitoring Plan (LINIP), and c) NPDLS permit renewal
requirements I he effluent samples must be analy/ed by a laboratory certified b) the Division for Method 1631,
and effluent results must be submitted with the applicable monthly Discharge Monitoring Report (DMR)
3 Grab Sampling Fhe hnvironmental Protection Agench (EPA) currently recommends that mercury samples for
Method 1631 analysts be collected as grab samples, since automatic composite samplers may be more subject to
contamination Ihereforc, the Division will allow permittees to collect single grab samples dircethv into lab-
proNided sample bottles for permit requirements, wen though the NPDLS permit may spcaf) "compositc"
samples for mercury 1 he grab sample must be represcntativc of the discharge
4 1 aboratory Reporting Level Based on the Division's review of commercial laboratories currcri performing
Method 1631, a majonn of labs were reporting a minimum Iced of quanmtanon (MI-) of other 10 ng/I or kss
1 he Din ision will require an NIL of I ng/I beginning 9/ 1 /2003, which is considered reasonable and economicalh
achievable
5 field Blank Collection Method 1631 requires that e minimum of one field blank iccompant each sct of samples
collected from the same site at the same time the field blank is used to idennfl contamination during sample
collection and transport activities If mercurl is present in the field blank at levels that would compromise reliable
measurumcnt of mercur) in the wntcwatcr sample, you should tsSUnle th n the cfflucnt sample was contaminated
during collection or transit, and )ou will need to eliminate am source of contamination that has been identified
fhe permitted shall report all effluent sample results on the applicable monthh DlMR If a field blank fails to
meet (juahtn control criteria, the permittee should note that fiet in the DMR Comments Section, and ippend the
lab sheet for that field blank For those facilities sanphng for mercury under a hmited monitoring frequencv
(cluarterl) or Icss, such as Pretreatment I lt\IP/Slt\IP monitoring), )ou must resample if the field blanks are
outside quahty control criteria I Iowever, for those faclmcs with more frcqucnt cfflucnt monitoring requirements
N C Division of Water Quality 1617 Mail Service Center Raleigh NC 27699 1617 [phone]
Customer Service 1 800 623 7748
►mot 1
NCDENR

NI'DES McI(AIry Rcquuctncnl
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(I c, monthk of more ftequ( Itt), iLsvnplmg Is not Iequucd If field bivil, quthty control cntcna are nor ichievcd
Co I I given s ugiplc CFLtit RcIU to NlLthad 1631 RLVJ1 1011 L, (Scwon 9 4 5 2- Qu IIM Connol- field Winks) foi
spcufic qualm connol cntctia icgvchng field blank ucyxabdlty'Ind cfflucnt simple iclnbdin
6 field 131Ink Subtraction Method 1631 prmides fm subtrauion of field blinks (piowdccl them meet quahty
connol ci terra defined ibovc) horn the cftluuit sunplL result if duniLd appropr-ite bl t regulitory agenev
Upon tcview, the Division will not allow field blink xibtmetion from cfflucnt samples for rcportmg purposes
Based on a recent stud\ using Method 1631 for \\astewater samples collected at 38 \%astewater treauncnt plants,
field blank concentrations were gogetalh below the ni thod quanntgtton ILvel Iherefore, begummg 9/1/2003
the pernuttee shill report the result of the cfflucnt sunplc as providcd by the certified lab, without field blank
uibtrgction, on the monthly DNIR SUbMISSIOn In the e\ent of a mercer\ limits violation, the peunlnLL retains
the option to request remission of any penalty If the pertmucc bLheVeS that the violation resulted from
b rekground contamniation m Indic ucd by thL field blank, the pernn[tee will need to document that fact with field
blank qualm control data
7 Sample Preservation/Holding hinds Samples for total mercury anahsis by Method 1631 must bL collected in
❑ghtly-eippcd fluoropohmcr or gliss bottles and presLrvcd with BrCI or IICI within 48 hours of svnplc
collection the time to sample prescrvation may be extended to 28 days If a sample is oxidized in the sgmplc
bottle Samples must be vnlvzed within 90 days of sample collection
If you hav c anv questions about the contents of this letter, please contact the applicable Division staff listed below
Mercury Method
Rov Bud
919-733-3908, extension 213
CLrtificd Labs for Method 1631
I-rcd Bone
919-733-3908 extension 273
NPDCS Permitting
I om Belmck
919-733-5083, extension 543
NPDES Compliance
Vanessa Manuel
919-733-5083, Lxtension 532
NPDES Pretreatment
Dana Policy
919-733-5083, extension 523
Sincerely,
Original Signed By
Davits A Goodrich
Alan W Klimek, P E
eL 0igrdcop\) CLANC c/o Lew I licks, EnNuonmentgl Chemist Inc 6602 Windmill Wg1 Wilmington NC 28405
DWQ Regional Offices W Itcr Qualit)
cc (email) CPA Rcgion 4 Madol\ n Domim Nlarshall I h gtt
DWQ Water Qualitl Section, Regional Office Supers isors
DWQ I iborgtor\ SLLUOn StL%L IeddLr, Lirr} AuslLv Jim MLNLr RoA Byrd Fred Bone
DWQ Modeling/1 N1DI MichLllL Woolfolk
DWQ NPDCS Compliance V-mLssa Manual
DWQ PrLtrLrtmLnt Unit
DWQ NPDL'S Unit
NC Leal,niL of Nlumclpal¢iLs Anita %V itkms
NC L ibs Certified for Method 1631 e

z
NCO025445
Michael F Easley Governor
William G Ross Jr Secretary
North Carolina Department of Environment and Natural Resources
Alan W Klimek P E Director
Division of Water Quality
August30 2002
Subject NPDES Mercury Requirement
Implementation of EPA Method 1631
Dear NPDES Penruttee
Mercury continues to be a water quality concern throughout North Carolina Fish consumption advisones and
impaired stream segments as a result of elevated mercury levels have been issued for several locations NPDES
pernuttees have worked with the state to reduce potential risks from this pollutant including tasks associated with
collecting and reporting more accurate data The most commonly used laboratory analysis for total mercury (EPA
Method 245 1) has a method detection level of 0 2 ug/1 while the current water quality standard is an order of
magnitude lower at 0 012 ug/I Thus true compliance with the water quality standard could not be judged A
more recently approved laboratory method (EPA Method 1631) should produce a detection level below the water
quality standard which would allow the Division to assess potential water quality impacts from dischargers more
accurately Therefore this letter serves as notification to your facility that effective September It 2003 you will
be required to begin using EPA Method 1631 (or subsequent low-level mercury methods approved by EPA in
40 CFR 136) when analyzing for total mercury Your facility is subject to this new requirement because either 1)
your facility has a current total mercury limit in its NPDES permit that is <0 20 ug/i or 2) your facility has limited
mstream dilution (i a the mstream waste concentration (1WC) is >6%) This requirement complies with 15 A NCAC
2B 0505(e)(4) which requires that test procedures must produce detection and reporting levels below the permit
discharge requirements
Mercury laboratory Analysis - EPA Method 1631
On June 22 1999 the US EPA approved a new analytical method (EPA Method 1631) for measunng very low
concentrations of mercury in water Subsequent revisions to Method 1631 include Revision C (current approved
method) and Draft Revision D (scheduled for promulgation in October 2002) Method 1631 has a minimum level of
quantitation of 0 0005 ug/I (0 5 ng/1) which is 400-times more sensitive than Method 245 1 The new method
requires a clean laboratory environment which generally requires some lab retrofitting thus many pennittees will
likely contract a commercial lab to perform the analysis Based on data compiled by Ohio EPA commercial labs
that are currently analyzing for EPA Method 1631 charge between $50 90 per sample with turnaround times
ranging from 5 28 days Currently there is one commercial lab certified by North Carolina for EPA Method 1631
However it is anticipated that several additional labs will also offer this analysis in the future as the demand for
this method increases When selecting a lab to perform low level mercury analyses the permittee should review the
lab s performance expenence and reliability with the method as well as cost considerations Attachment A
provides additional information on this method
Mercury Clean Sampling Techniques - EPA Method 1669
The greatest nsk of contaminating the wastewater sample for low-level mercury analysis is dunng the sample
collection effort Thus those facilities subject to EPA Method 1631 will also need to evaluate clean sampling
recommendations provided in EPA Method 1669 Attachment A provides highlights on this method
NPDES Comphance
All mercury mondonng data submitted to the Division will be reviewed for compliance with current effluent limits
If the permit contains monitoring only the new method must still be used and the need for a permit limit
will be evaluated at a later date by comparing a statistical evaluation of the effluent data with the water
quality standard and corresponding allowable effluent concentration Therefore the potential problem of
sample contamination cannot be overemphasized since it could result in NPDES effluent limits for total mercury
increased monitoring costs and possibly unnecessary violations All data submitted to the Division for NPDES
compliance momtonng requirements are the responsibility of the permdtee Therefore facilities subject to this new
method are strongly encouraged to begin evaluating sampling methods and commercial labs before the deadline
date to ensure that field staff are properly trained in the use of clean sampling techniques and sampling and lab
procedures are fully developed to minimize sample contamination
sin
14LDENR
N C Division of Water Quality 1617 Mail Service Center Raleigh NC 27699 1617 [phone]
Customer Service 1 800 623 7748

V
NPDES Mercury Requirement
Page 2 of 3
Additional Information
For additional information and guidance regarding EPA Methods 1631 / 1669 the permittee may consult the
following resources
North Carolina Division of Water Quality
Laboratory Analysis Roy Byrd 919-733-3908 ext 213
Lab Certification lab Staff 919-733-3908
Clean Sampling Sandy Mort 919-733-2136 ext 245
NPDES Permitting Tom Belnick 919-733-5083 ext 543
Pretreatment Tom Poe 919 733-5083 ext522
US Environmental Protection Agency
Method 1631/1669 Questions Mana Gomez Taylor 202-566-1005
EPA Sample Control Center 703-461-2100
Websites
http //www epa state oh us/dsw/guidance/permitIOatt3 pdf
The state of Ohio EPA provides an updated listing of laboratories providing contract services for EPA
Method 1631 including costs turnaround time and lab contacts The labs are identified for informational
purposes only and do not constitute an endorsement The listed commercial laboratories may also provide
advice on training equipment and sampling techniques appropriate for Method 1631
http //www epa Eov/ost/methods/ 1631 html
This EPA site provides information on the 1631 Method requirements and implementation guidance
http //www esb enr state nc us/lab
This DWQ site provides information on EPA Methods (including 1669 clean sampling techniques) and a
listing of state -certified labs for EPA Method 1631
htto //www h2o enr state nc us/NPDES/NPDESweb html click Documents
This DWQ websde includes a copy of this letter plus a list of facilities currently subject to EPA Method
1631
Conclusion
The Division realizes that changing the method of mercury measurement will not be without difficulty on the part of
the pernuttees The requirement Will affect approximately 155 facilities with mercury limits and/or monitoring
requirements These pernuttees will need to evaluate available laboratories costs and sampling techniques For
these reasons the implementation date for EPA Method 1631 was delayed until September 1 2003 The Division
thanks you for your cooperation and understanding in this matter If you have any questions about the contents of
this letter please contact the applicable staff listed above _
Sincerely
°
7
J William Reid PE
Supervisor Point Source Branch
cc (hardcopy) CLANC c/o Lew Hicks Environmental Chemistry Inc 6602 Windmill Way Wilmington NC 28405
cc (email) EPA Region 4 Marshall Hyatt Scott Gordon Roosevelt Childress
DWQ Water Quality Section Coleen Sullins Regional Offices
DWQ Laboratory Section Steve Tedder Larry Ansley Jim Meyer Roy Bvrd Conine Brower
DWQ Aquatic Toxicology Unit Sandy Mort
DWQ Pretreatment Unit Tom Poe
DWQ Modeling/TMDL Michelle Woolfolk
DWQ NPDES Compliance Unit Shannon Langley
DWQ NPDES Unit
MCIC Michael Johnson
NC League of Municipalities Paula Thomas
Clean Water Fund of NC Hope Taylor
Severn Trent Lab Ohio Mark Bruce

t
NPDES Mercury Requirement
Page 3 of 3
ATTACHMENT A
Summary of EPA Methods 1631/1669
Effluent samples collected for mercury may become contaminated by numerous routes including 1) metal -
containing labware reagents containers and sampling equipment 2) improperly cleaned or stored equipment and
3) atmospheric mercury inputs in dirt and dust Even human contact can be a source of mercury contamination
(e g mercury amalgam fillings in the mouths of lab/field personnel can contaminate samples directly exposed to
exhalation) Thus it is essential that every effort be made to minimize sample contamination during collection The
US EPA provides recommendations to minimize contamination during sample collection in EPA Method 1669
Sampling Ambient Water for Determination of Trace Metals at EPA Water Quality Criteria Leuels This guidance
describes a clean hands/dirty hands sampling technique to collect mercury samples which is ideally performed
with two people A designated clean hands sampler handles all operations involving direct contact with the
sample bottle while the dirty hands sampler is responsible for all activities that do not involve direct contact with
the sample bottle This team sampling technique is recommended as a means to minimize sample contamination
but is not required The US EPA is developing a trace metal sampling guidance strictly for effluent collection
(Method 1670) The permittee will need to evaluate the various sampling recommendations and develop a sampling
strategy appropriate for their particular situation The overall philosophy behind any mercury sampling strategy
should be to ensure that any object or substance that contacts the sample is nonmetallic and free from any
material that may contain metals in order to produce a reliable mercury measurement
Requirements and recommendations for EPA Method 1631
and clean sampling for low level mercury include
• It is strongly recommended that the permittee discuss sample collection preservation and shipping
requirements with their laboratory to ensure that the most current requirements of Method 1631 will
be met There have been several revisions to EPA Method 1631 and Revision D is proposed
• Each laboratory must perform and meet the minimum requirements of Method 1631 Quality Control
• Effluent samples for mercury analysis must be collected in clean fluoropolymer or borosihcate glass
containers It is recommended that the permittee request appropriate clean sample bottles or a
mercury sampling kit from their lab
• Method 1631 requires that a nummum of one field blank accompany each set of samples collected at a
given site The field blank is used to identify contamination from sample collection and transport If
mercury is present in the field blank at levels that would compromise reliable measurement of mercury
in the wastewater sample you should assume that the sample was contaminated during collection or
transit and you will need to ehrrunate any source of contamination that has been identified and
possibly resample Including the field blank the permittee should budget for two samples per
monitoring event
• Samples must be preserved or analyzed within 48 hours after collection Samples do not need to be
refrigerated/iced during shipment provided they are tightly capped shipped overnight to the lab and
preserved or analyzed by the lab within 48 hours of collection (per Draft Revision D)
• If the samples are preserved within 48 hours then they have a maximum holding time of 90 days prior
to analysis (per Draft Revision D)
• Sampling personnel must wear clean non -talc latex gloves during sample collection and handling
• EPA currently recommends that mercury samples for Method 1631 analysis be collected as grab
samples since automatic composite samplers may be subject to contarrunation and loss of mercury via
volatilization Therefore the Division will allow permittees to collect single grab samples directly into
lab -provided sample bottles for peraut requirements The grab sample must be representative of the
discharge
• If the person collecting the sample cannot directly reach the wastewater stream a pole type sampler
may be attached to the sample bottle to extend the reach for sample collection The pole and bottle
clamp should be made of plastic and/or stainless steel and the mouth of the bottle should be held
facing upstream of the pole The use of a transfer vessel should be avoided
• All sampling equipment must be nonmetallic or free of material that may contain metals All materials
that will directly or indirectly contact the sample must be cleaned using the procedures in Method
1631
• To minimize atmospheric contamination do not sample during rainy weather or when the wind could
blow dust particles into the sample bottle To minimize human contamination do not breathe into the
sample bottle if you have mercury amalgam fillings in your teeth
• Sampling personnel should be trained in techniques for sampling mercury at low levels Sample
collection via the clean hands/dirty hands technique is recommended but not required
• Since Method 1631 is performance -based there is some flexibility in Method requirements