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Meeting the Lead and Meeting the Lead and Copper Rule Copper Rule

RequirementsRequirementsAlabama-Mississippi

AWWA Education WorkshopJanuary 2014

Vernon L. SnoeyinkUniversity of Illinois

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What should you What should you expect from this expect from this presentation?presentation? An understanding of the An understanding of the

regulations and health effects of regulations and health effects of Pb and CuPb and Cu

A discussion of possible changes A discussion of possible changes to the Lead and Copper Rule (LCR)to the Lead and Copper Rule (LCR)

Important concepts Important concepts Scale formation and metal ion Scale formation and metal ion

releaserelease Scale stability and conversion issuesScale stability and conversion issues Constant pH stabilizes scaleConstant pH stabilizes scale Phosphate inhibitors reduce Pb Phosphate inhibitors reduce Pb

solubilitysolubility

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Copper RegulationsCopper Regulations

Action Level (AL) is 1.3 mg/L (90Action Level (AL) is 1.3 mg/L (90thth percentile value)percentile value)

AL samples: 1 liter first draw after AL samples: 1 liter first draw after 6 hours of stagnation6 hours of stagnation

Basis:Basis: Health reference: prevent nauseaHealth reference: prevent nausea SMCL: 1.0 mg/L based on taste and SMCL: 1.0 mg/L based on taste and

stainingstaining

Ref: Advances in Water Research, Oct-Dec 2013, vol. 23, Ref: Advances in Water Research, Oct-Dec 2013, vol. 23, no. 4.no. 4.

Ref for Cu Corrosion: Chapter by Schock in Water Quality Ref for Cu Corrosion: Chapter by Schock in Water Quality &Treatment, 6&Treatment, 6thth Ed. AWWA/McGraw Hill, 2011 Ed. AWWA/McGraw Hill, 2011

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Copper ControlCopper Control In general, pH below 7 causes high Cu In general, pH below 7 causes high Cu Corrosion produces scale, and scale Corrosion produces scale, and scale

solubility determines Cu concentrationsolubility determines Cu concentration Cu concentration depends on pH, type Cu concentration depends on pH, type

of scale that forms, and alkalinity, and of scale that forms, and alkalinity, and whether the pipe is newwhether the pipe is new

Low pH (~7 or less) and high alkalinity Low pH (~7 or less) and high alkalinity (~ 300 mg/L as CaCO(~ 300 mg/L as CaCO33) ) AL AL exceedanceexceedance

Reduce Cu by increasing pH (if CaCOReduce Cu by increasing pH (if CaCO33 doesn’t precipitate) or orthophosphatedoesn’t precipitate) or orthophosphate

Ref: S. Grace et al. “Control of new copper corrosion in Ref: S. Grace et al. “Control of new copper corrosion in high-alkalinity drinking water” high-alkalinity drinking water” JAWWAJAWWA Jan. 2012 Jan. 2012 4

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Lead Regulations and Lead Regulations and SourcesSources

AL is 15 AL is 15 μμg/L (90g/L (90thth percentile) percentile) Lead service lines & lead/tin solder Lead service lines & lead/tin solder

outlawed in 1986 outlawed in 1986 Brass fixtures in homes, meters, Brass fixtures in homes, meters,

water coolers etc. water coolers etc. The LCR (1991) says Pb ≤ 8 % The LCR (1991) says Pb ≤ 8 % As of Jan 2014: Pb ≤ 0.25% of wetted As of Jan 2014: Pb ≤ 0.25% of wetted

surface of fixtures (2011 Safe surface of fixtures (2011 Safe Drinking Water Act Amendment)Drinking Water Act Amendment)

Proposed revision to the LCR Proposed revision to the LCR expected in 2014. Speculation expected in 2014. Speculation only on what it might includeonly on what it might include

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How does Lead Get Into How does Lead Get Into Drinking Water?Drinking Water?

Potomac River

Main Lead Service LineWhen water spends several hoursin the lead service line withoutmoving, it can absorb lead fromthe service line.

When waterspends severalhours in theinternal plumbingwithout moving,it can absorb(generally smaller)levels of leadfrom fixtures andfaucets.

Washington Aqueduct

Treats Water

Water in main ALWAYS containsvery low levels of lead (lessthan 2 ppb)

Water contains the same low levels of lead as in the mainbut may pick up low levels of leadfrom water meters.

Non-lead Service Line*

Internal Plumbing

TreatmentPlant

DC WASADistributes Water

to Residents

DC Water: From Source to Tap

*A small fraction of homes have brass service lines that can also contribute low levels of lead.

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Health Effects of LeadHealth Effects of LeadCDC: CDC: ““No Safe LevelNo Safe Level””

Health effects related to blood lead levels Health effects related to blood lead levels (CDC: 5 (CDC: 5 μμg/dL)g/dL)

Infants and young children most susceptibleInfants and young children most susceptible Primary source is lead paint dustPrimary source is lead paint dust Neurological damage, impact on IQ, Neurological damage, impact on IQ,

probable human carcinogen (renal tumors probable human carcinogen (renal tumors in rats)in rats)

MCLG of zeroMCLG of zero

Brown, M. J.; et al. Association between children's blood lead levels, lead Brown, M. J.; et al. Association between children's blood lead levels, lead service lines, and water disinfection, Washington, DC, 1998-2006. Environ service lines, and water disinfection, Washington, DC, 1998-2006. Environ Res 2011, 111 (1), 67-74. Res 2011, 111 (1), 67-74.

Brown, M. J.; Margolis, S. Lead in drinking water and human blood lead Brown, M. J.; Margolis, S. Lead in drinking water and human blood lead levels in the USA. Morbidity and Mortality Weekly Report 2012, 61(Suppl; levels in the USA. Morbidity and Mortality Weekly Report 2012, 61(Suppl; August 10, 2012),August 10, 2012),

1-9.1-9. Wat. Qual. &Treat.,Wat. Qual. &Treat., 5 5thth Ed, Amer Wat. Works Assoc. , McGraw Hill, 1999 Ed, Amer Wat. Works Assoc. , McGraw Hill, 1999 Edwards et al. Edwards et al. ES&TES&T Jan 27, 2009 Jan 27, 2009

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Good Housekeeping, Feb. 2005 issue

The Presence of Lead Hurts Public Confidence

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Pb in water usually Pb in water usually comes from Pb scales comes from Pb scales

Pb Pb Pb Pb2+2+ + 2e (corrosion) + 2e (corrosion) Electron acceptors: OElectron acceptors: O22, HOCl, OCl, HOCl, OCl--, NH, NH22ClCl

Pb scales: Pb scales: Lead carbonates: PbCOLead carbonates: PbCO33 & Pb & Pb33(CO(CO33))22(OH)(OH)22

Lead phosphates: PbLead phosphates: Pb33(PO(PO44))22 & Pb & Pb55(PO(PO44))33OHOH PbOPbO22 may also be formed if free chlorine is may also be formed if free chlorine is

used in the distribution systemused in the distribution system Non-crystalline lead solids and non-Non-crystalline lead solids and non-

lead solids may be importantlead solids may be important

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We have 3 alternatives We have 3 alternatives for using water quality for using water quality to control Pbto control Pb1.1. Use orthophosphate, POUse orthophosphate, PO44, pH 7.2-, pH 7.2-

7.87.82.2. Use pH 9 -9.5 with an alkalinity > Use pH 9 -9.5 with an alkalinity >

35 mg/L as CaCO35 mg/L as CaCO33

3.3. Use free chlorine to form PbOUse free chlorine to form PbO22

The diagram on the next slide can The diagram on the next slide can be used to explain these optionsbe used to explain these options

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11Schock, USEPA

pC-pH Diagram shows pH range of low solubility

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Elemental Distribution – Chicago, ILElemental Distribution – Chicago, ILRed Color is proportional to Red Color is proportional to

element densityelement densityNote the location of most of the Note the location of most of the

leadleadAl Ca Fe

Mn P PbSi

BSE Image

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Washington, D.C. Washington, D.C.

Change from secondary Change from secondary disinfection with free disinfection with free

chlorine to chlorine to monochloramine led to monochloramine led to

severe LCR violationsevere LCR violationRefs: •EPA website•Schock and Giani, Proc Wat Qual Tech Conf, San Antonio, Nov 2004, Amer Wat. Wrks Assoc., Denver

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2001 – 2002 Lead AL 2001 – 2002 Lead AL was exceededwas exceeded

9090thth percentile was 75 ppb) percentile was 75 ppb)

The Washington Aqueduct (WA) The Washington Aqueduct (WA) treats Potomac River water and treats Potomac River water and sells it to Washington DC, sells it to Washington DC, Arlington County and Falls Church. Arlington County and Falls Church. DC WASA (now DC Water) is DC WASA (now DC Water) is

responsible for meeting the ALresponsible for meeting the AL WA is responsible for treating waterWA is responsible for treating water Arlington Co and Falls Church never Arlington Co and Falls Church never

exceeded the ALexceeded the AL

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Lead Service LinesLead Service Lines

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DC Lead Compliance DC Lead Compliance HistoryHistory

Schock and Giani, 2004

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PbOPbO22 rapidly converts rapidly converts to Pbto Pb2+ 2+ when free when free chlorine is changed to chlorine is changed to NHNH22ClClVery likely: Very likely: PbPb00 is the electron donor is the electron donor PbOPbO22 is the electron acceptor is the electron acceptorPbPb0 0 + PbO+ PbO22 + 4 H + 4 H++ 2 Pb 2 Pb2+ 2+ + 2 H+ 2 H22OO Product is PbProduct is Pb2+2+

Reaction is very rapid IF Reaction is very rapid IF PbOPbO22 is in is in contact with lead pipecontact with lead pipe OrOr if PbO if PbO22 is in outer layer and is in outer layer and scale is scale is

conductingconductingPOPO44

3- 3- must be present to convert Pbmust be present to convert Pb2+ 2+

to scale, to prevent high Pb to scale, to prevent high Pb concentrationsconcentrations

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Lead Profiles show Lead Profiles show that 1-liter first-draw that 1-liter first-draw samples do not give samples do not give

the highest lead the highest lead concentrationconcentration

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Peak lead values occur Peak lead values occur in the service linein the service line

Schock and Giani, 2004

NH2Cl

Free Cl

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Water Quality Affects Water Quality Affects Scale Properties. Keep Scale Properties. Keep

pH constantpH constant At Washington Aqueduct, At Washington Aqueduct, variable variable

pHpH:: 7 to 8.5: high in winter, low in summer7 to 8.5: high in winter, low in summer Cause: post filter lime feed turbidityCause: post filter lime feed turbidity

AlkalinityAlkalinity: typically 60 mg/L as CaCO: typically 60 mg/L as CaCO33 but highly variable; high in summerbut highly variable; high in summer

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Desktop Study Showed Desktop Study Showed 1) High pH not an 1) High pH not an option option 2) o-PO2) o-PO44 best best CaCOCaCO33 precipitated above pH 8.5 precipitated above pH 8.5

but 9but 9++ required required o-POo-PO44 (H (H33POPO44) likely best ) likely best Trial: apply to part of the Trial: apply to part of the

distribution system before full-scaledistribution system before full-scale Recommended pipe loop study to Recommended pipe loop study to

optimize treatmentoptimize treatment

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Full-Scale Full-Scale ImplementationImplementation

Elevated total coliform counts, but no Elevated total coliform counts, but no Coliform Rule violation Coliform Rule violation

Colored water complaints in DC (1-2 a Colored water complaints in DC (1-2 a day). Caused by the phosphate?day). Caused by the phosphate?

Unable to flush prior to implementationUnable to flush prior to implementation

Lessons learned: Lessons learned: Flush before implementationFlush before implementation Document quality before implementationDocument quality before implementation Announce implementation before actual Announce implementation before actual

changechange

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Pipe Loop Study DesignPipe Loop Study Design

Evaluate alternate control Evaluate alternate control strategiesstrategies

Use harvested lead service lines Use harvested lead service lines Seven operating conditions, three Seven operating conditions, three

loops each (21 loops total)loops each (21 loops total)

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Loop 4 vs 6 show POLoop 4 vs 6 show PO44 EffectEffect

Figure 2-1: Effect of Adding a Phosphate Inhibitor on Total Lead Concentrations - Comparison of Racks 4 & 6

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10

20

30

40

50

60

70

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2/17/05 3/30/05 5/10/05 6/20/05 7/31/05 9/10/05 10/21/05 12/1/05 1/11/06

Date

Tota

l Lea

d Co

ncen

tratio

n (u

g/L)

Loop 4A Loop 4B Loop 4CLoop 6A Loop 6B Loop 6C

= No Phosphate Inhibitor= 3.0 mg/L Phosphoric Acid

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Results of Pipe Loop Results of Pipe Loop and Full Scale Studyand Full Scale Study

No reason to use zinc No reason to use zinc orthophosphate instead of orthophosphate instead of phosphoric acid as POphosphoric acid as PO44 source source

Lowering the chloramine dose Lowering the chloramine dose did not reduce lead did not reduce lead concentrationsconcentrations

Application of 3.5 mg/L HApplication of 3.5 mg/L H33POPO44 as POas PO44 to the full scale system to the full scale system achieved compliance in the achieved compliance in the 1st full sampling period. 1st full sampling period.

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Results of Pipe Loop Results of Pipe Loop and Full Scale Studyand Full Scale Study Lead levels continued to Lead levels continued to

decrease as the POdecrease as the PO44 dose was dose was lowered from 3 to 1 mg/L (in lowered from 3 to 1 mg/L (in pipe loop)pipe loop)

No evidence of an effect of a No evidence of an effect of a chlorine burn on lead levels chlorine burn on lead levels after conversion to a Pb(II) scaleafter conversion to a Pb(II) scale

Lead concentrations are higher Lead concentrations are higher the higher the temperaturethe higher the temperature

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LCR Lead Compliance LCR Lead Compliance DataData

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PO4 feed started in fall 2004at 3.5 mg/L as PO4

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What Is Occurring What Is Occurring Because of DC Because of DC ExperienceExperience TheThe““action levelaction level”” has become a has become a

““de factode facto”” MCL MCL Confidence of public in water Confidence of public in water

supplysupply EPA taking closer look at LCREPA taking closer look at LCR EPA examining LSL sampling EPA examining LSL sampling

times (not just first draw)times (not just first draw)

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Chicago Case HistoryChicago Case History

Lake Michigan water, Alk ~ 100 Lake Michigan water, Alk ~ 100 mg/L, Ca ~ 2 mM, Alum mg/L, Ca ~ 2 mM, Alum coagulation, free chlorine, ortho coagulation, free chlorine, ortho plus polyphosphate inhibitorplus polyphosphate inhibitor

ProblemProblem: phosphate forms a : phosphate forms a precipitate with residual aluminum precipitate with residual aluminum that increases resistance to water that increases resistance to water flow in pipesflow in pipes

Ref: Atasi et al., Proc AWWA Annual Conf., Ref: Atasi et al., Proc AWWA Annual Conf., Orlando, 2004Orlando, 2004

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Aluminum Phosphate: Chicago Aluminum Phosphate: Chicago Case HistoryCase History

1 mg/L as PO1 mg/L as PO44 of an ortho-polyphosphate of an ortho-polyphosphate

blend is added to control lead release from blend is added to control lead release from lead service lineslead service lines

Precipitation of AlPOPrecipitation of AlPO44 forms fine particles forms fine particles

that deposited on walls of a 72” and a 90” that deposited on walls of a 72” and a 90” cement lined mainscement lined mains

Residual Al in the summer is ~ 175 μg/LResidual Al in the summer is ~ 175 μg/L C-factor was reduced from about 135 to 95C-factor was reduced from about 135 to 95

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Recent Chicago Results Recent Chicago Results

Del Toral et al, ES&T 2013Del Toral et al, ES&T 2013

LCR values for the last decade are LCR values for the last decade are ~6 ug/L ~6 ug/L

Peak values are service line Peak values are service line samples and are ~ 2xALsamples and are ~ 2xAL

LSL disturbances cause the LSL disturbances cause the highest values (construction, LSL highest values (construction, LSL leak repair, meter installation…)leak repair, meter installation…)

Should the LCR be changed to Should the LCR be changed to base compliance on the sample base compliance on the sample from the LSL?from the LSL?

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Important remaining Important remaining questions: The service questions: The service line problemline problem Replacement of lead service lines Replacement of lead service lines

poses a serious problem.poses a serious problem. Partial lead service line Partial lead service line

replacement of questionable replacement of questionable benefit and may worsen the benefit and may worsen the situationsituation

Full service line replacement is Full service line replacement is costly and especially difficult to costly and especially difficult to mandate in our old large citiesmandate in our old large cities

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Final ThoughtsFinal Thoughts

Lead in drinking water is an Lead in drinking water is an important problem that will be with important problem that will be with us for awhile.us for awhile.

The low lead content requirement for The low lead content requirement for

brass will help decrease the problembrass will help decrease the problem

We will have to find some way to We will have to find some way to make the lead service line problem make the lead service line problem go awaygo away

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