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Meeting the Lead and
Copper Rule Requirements
Alabama-Mississippi
AWWA Education Workshop
January 2014
Vernon L. Snoeyink
University of Illinois
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What should you expect from this presentation?
An understanding of the regulations and health effects of Pb and Cu
A discussion of possible changes to the
Lead and Copper Rule (LCR)
Important concepts
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Scale formation and metal ion release
Scale stability and conversion issues
Constant pH stabilizes scale
Phosphate inhibitors reduce Pb solubility
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Copper Regulations
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Action Level (AL) is 1.3 mg/L (90 th percentile value)
AL samples: 1 liter first draw after 6 hours of stagnation
Basis:
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Health reference: prevent nausea
SMCL: 1.0 mg/L based on taste and staining
Ref: Advances in Water Research, Oct-Dec 2013, vol. 23, no. 4.
Ref for Cu Corrosion: Chapter by Schock in Water Quality
&Treatment, 6 th Ed. AWWA/McGraw Hill, 2011
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Copper Control
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In general, pH below 7 causes high Cu
Corrosion produces scale, and scale solubility determines Cu concentration
Cu concentration depends on pH, type of scale that forms, and alkalinity, and whether the pipe is new
Low pH (~7 or less) and high alkalinity (~
300 mg/L as CaCO
3
)  AL exceedance
Reduce Cu by increasing pH (if CaCO doesn’t precipitate) or orthophosphate
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Ref: S. Grace et al. “Control of new copper corrosion in highalkalinity drinking water” JAWWA Jan. 2012
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Lead Regulations and Sources
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AL is 15 μ g/L (90 th percentile)
Lead service lines & lead/tin solder outlawed in 1986
Brass fixtures in homes, meters, water coolers etc.
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The LCR (1991) says Pb ≤ 8 %

As of Jan 2014: Pb ≤ 0.25% of wetted surface of fixtures (2011 Safe Drinking
Water Act Amendment)
Proposed revision to the LCR expected in 2014. Speculation only on what it might include
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How does Lead Get Into
Drinking Water?
DC Water: From Source to Tap
Washington
Aqueduct
Treats Water
Potomac River
Treatment
Plant
DC WASA
Distributes Water to Residents
Non-lead Service Line*
Water contains the same low levels of lead as in the main but may pick up low levels of lead from water meters.
Main
Water in main ALWAYS contains very low levels of lead (less than 2 ppb)
*A small fraction of homes have brass service lines that can also contribute low levels of lead.
Internal
Plumbing
When water spends several hours in the internal plumbing without moving, it can absorb
(generally smaller) levels of lead from fixtures and faucets.
Lead Service Line
When water spends several hours in the lead service line without moving, it can absorb lead from the service line.
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Health Effects of Lead
CDC:
No Safe Level
Health effects related to blood lead levels
(CDC: 5 μg/dL)
Infants and young children most susceptible
Primary source is lead paint dust
Neurological damage, impact on IQ, probable human carcinogen (renal tumors in rats)
MCLG of zero
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Brown, M. J.; et al. Association between children's blood lead levels, lead service lines, and water disinfection, Washington, DC, 1998-2006. Environ Res 2011, 111 (1), 67-
74.
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; August 10, 2012),
1-9.
Wat. Qual. &Treat., 5 th Ed, Amer Wat. Works Assoc. , McGraw Hill, 1999
Edwards et al. ES&T Jan 27, 2009
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The Presence of Lead Hurts
Public Confidence
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Good Housekeeping, Feb. 2005 issue
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Pb in water usually comes from Pb scales
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Pb  Pb 2+ + 2e (corrosion)
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Electron acceptors: O
2
, HOCl, OCl , NH
2
Cl
Pb scales:
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Lead carbonates: PbCO
3
Lead phosphates: Pb
3
& Pb
(PO
4
)
2
3
(CO
3
& Pb
5
)
2
(OH)
(PO
4
)
3
2
OH
PbO
2 may also be formed if free chlorine is used in the distribution system
Non-crystalline lead solids and non-lead solids may be important
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We have 3 alternatives for using water quality to control
Pb
1.
2.
3.
Use orthophosphate, PO
4
, pH 7.2-7.8
Use pH 9 -9.5 with an alkalinity > 35 mg/L as CaCO
3
Use free chlorine to form PbO
2
The diagram on the next slide can be used to explain these options
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pC-pH Diagram shows pH range of low solubility
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Schock, USEPA
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Elemental Distribution – Chicago, IL
Red Color is proportional to element density
Note the location of most of the lead
BSE Image Al Ca Fe
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Si Mn P Pb
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Washington, D.C.
Change from secondary disinfection with free chlorine to monochloramine led to severe LCR violation
Refs:
•
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 was exceeded
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90 th percentile was 75 ppb)
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The Washington Aqueduct (WA) treats
Potomac River water and sells it to
Washington DC, Arlington County and
Falls Church.
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DC WASA (now DC Water) is responsible for meeting the AL
WA is responsible for treating water
Arlington Co and Falls Church never exceeded the AL
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Lead Service Lines
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DC Lead Compliance History
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Schock and Giani, 2004
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PbO
2 rapidly converts to Pb 2+ when free chlorine is changed to NH
2
Cl
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Very likely:
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Pb 0 is the electron donor
PbO
2 is the electron acceptor
Pb 0 + PbO
2
+ 4 H + 
Product is Pb 2+
Reaction is very rapid IF
2 Pb 2+ + 2 H
2
O
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PO
PbO
2 is in contact with lead pipe
Or if PbO
2 is in outer layer and scale is conducting
4
3must be present to convert Pb 2+ to scale, to prevent high Pb concentrations
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Lead Profiles show that 1liter first-draw samples do not give the highest lead concentration
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Peak lead values occur in the service line
100
NH
2
Cl
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Free Cl
Schock and Giani, 2004
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Water Quality Affects Scale
Properties. Keep pH constant
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At Washington Aqueduct, variable pH:
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7 to 8.5: high in winter, low in summer
Cause: post filter lime feed turbidity
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Alkalinity: typically 60 mg/L as CaCO
3 highly variable; high in summer but
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Desktop Study Showed
1) High pH not an option
2) o-PO
4 best
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CaCO
3 precipitated above pH 8.5 but 9 + required o-PO
4
(H
3
PO
4
) likely best
Trial: apply to part of the distribution system before full-scale
Recommended pipe loop study to optimize treatment
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Full-Scale Implementation
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Elevated total coliform counts, but no
Coliform Rule violation
Colored water complaints in DC (1-2 a day).
Caused by the phosphate?
Unable to flush prior to implementation
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Lessons learned:
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Flush before implementation
Document quality before implementation
Announce implementation before actual change
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Pipe Loop Study Design
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Evaluate alternate control strategies
Use harvested lead service lines
Seven operating conditions, three loops each (21 loops total)
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Loop 4 vs 6 show PO
4
Effect
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Figure 2-1 : Effect of Adding a Phosphate Inhibitor on Total Lead Concentrations - Comparison of Racks 4 & 6
60
50
40
80
70
30
20
10
0
2/17/05
Loop 4A
Loop 6A
3/30/05
Loop 4B
Loop 6B
5/10/05
Loop 4C
Loop 6C
6/20/05 7/31/05
Date
9/10/05
= No Phosphate Inhibitor
= 3.0 mg/L Phosphoric Acid
10/21/05 12/1/05 1/11/06
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Results of Pipe Loop and Full
Scale Study
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No reason to use zinc orthophosphate instead of phosphoric acid as PO
4 source
Lowering the chloramine dose did not reduce lead concentrations
Application of 3.5 mg/L H
PO
4
3
PO
4 as to the full scale system achieved compliance in the 1st full sampling period.
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Results of Pipe Loop and Full
Scale Study
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Lead levels continued to decrease as the PO
4 dose was lowered from
3 to 1 mg/L (in pipe loop)
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No evidence of an effect of a chlorine burn on lead levels after conversion to a Pb(II) scale
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Lead concentrations are higher the higher the temperature
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LCR Lead Compliance Data
PO4 feed started in fall 2004 at 3.5 mg/L as PO4
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What Is Occurring Because of
DC Experience
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The “ action level ” has become a “ de facto ” MCL
Confidence of public in water supply
EPA taking closer look at LCR
EPA examining LSL sampling times
(not just first draw)
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Chicago Case History
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Lake Michigan water, Alk ~ 100 mg/L,
Ca ~ 2 mM, Alum coagulation, free chlorine, ortho plus polyphosphate inhibitor
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Problem: phosphate forms a precipitate with residual aluminum that increases resistance to water flow in pipes
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Ref: Atasi et al., Proc AWWA Annual Conf., Orlando,
2004
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Aluminum Phosphate: Chicago
Case History
 1 mg/L as PO
4 of an ortho-polyphosphate blend is added to control lead release from lead service lines
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Precipitation of AlPO
4 forms fine particles that deposited on walls of a 72” and a 90” cement lined mains
Residual Al in the summer is ~ 175 μg/L
 C-factor was reduced from about 135 to 95
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Recent Chicago Results
Del Toral et al, ES&T 2013
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LCR values for the last decade are ~6 ug/L
Peak values are service line samples and are ~ 2xAL
LSL disturbances cause the highest values (construction, LSL leak repair, meter installation…)
Should the LCR be changed to base compliance on the sample from the
LSL?
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Important remaining questions:
The service line problem
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Replacement of lead service lines poses a serious problem.
Partial lead service line replacement of questionable benefit and may worsen the situation
Full service line replacement is costly and especially difficult to mandate in our old large cities
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Final Thoughts
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Lead in drinking water is an important problem that will be with us for awhile.
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The low lead content requirement for brass will help decrease the problem
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We will have to find some way to make the lead service line problem go away
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