CDJk
Optimal Corrosion Control
Treatment Evaluation Technical
Uniled Stattt
Recommendations for Primacy
Agencies and Public Water Systems
-------
Office of Water (4606M)
EPA816-B-16-003
March 2016
-------
Disclaimer
This document provides technical recommendations to primacy agencies and public water
systems (PWSs) in determining the most appropriate treatment for controlling lead and copper
and complying with the corrosion control treatment (CCT) requirements of the Lead and
Copper Rule (LCR) that are in place at the time of document publication.
The statutory provisions and EPA regulations described in this document contain legally binding
requirements. This document is not a regulation itself, nor does it change or substitute for
those provisions and regulations. Thus, it does not impose legally binding requirements on EPA,
states or the regulated community. This document does not confer legal rights or impose legal
obligations upon any member of the public.
While EPA has made every effort to ensure the accuracy of the discussion in this document, the
obligations of the regulated community are determined by statutes, regulations or other legally
binding requirements. In the event of a conflict between the discussion in this document and
any statute or regulation, this document would not be controlling.
The general descriptions provided here may not apply to a particular situation based upon the
circumstances. Interested parties are free to raise questions and objections about the
substance of these technical recommendations and the appropriateness of the application of
these technical recommendations to a particular situation. EPA and other decision makers
retain the discretion to adopt approaches on a case-by-case basis that differ from those
described in this document, where appropriate.
Mention of trade names or commercial products does not constitute endorsement or
recommendation for their use.
This is a living document and may be revised periodically without public notice. EPA welcomes
public input on this document at any time.
-------
This Page Intentionally Left Blank
-------
Table of Contents
Chapter 1: Introduction 1
1.1 Purpose and Audience 1
1.2 Document Organization 2
1.3 How to Use this Document 3
Chapter 2 : Background Information 4
2.1 Regulatory Actions to Control Lead and Copper in Drinking Water 4
2.1.1 Lead and Copper Regulation 4
2.1.2 Control of Lead Content in Plumbing Components 6
2.2 Sources of Lead and Copper 8
2.2.1 Corrosion and Metals Release 9
2.2.2 Lead and Copper-Containing Material 10
2.3 Water Quality Factors Affecting Release of Lead and Copper 12
2.3.1 pH, Alkalinity and DIC 12
2.3.2 Corrosion Inhibitors 13
2.3.3 Hardness (Calcium and Magnesium) 14
2.3.4 Buffer Intensity 14
2.3.5 Dissolved Oxygen 15
2.3.6 Oxidation-Reduction Potential 16
2.3.7 Ammonia, Chloride, and Sulfate 17
2.3.8 Natural Organic Matter 18
2.3.9 Iron, Manganese, and Aluminum 19
2.4 Physical and Hydraulic Factors Affecting Release of Lead and Copper 20
2.4.1 Physical Disturbances 20
2.4.2 Hydraulic Factors 20
2.4.3 Water Use 21
2.4.4 Water Temperature 21
Chapter 3 : Corrosion Control Treatment for Lead and Copper 22
3.1 Available Corrosion Control Treatment Methods 22
3.1.1 pH/Alkalinity/DIC Adjustment 23
3.1.2 Phosphate-Based Inhibitors 25
3.1.3 Silicate Inhibitors 25
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems i
-------
3.2 Technical Recommendations for Selecting Treatment Alternatives 26
3.2.1 Technical Recommendations for Reviewing Water Quality Data and Other
Information (STEP 1) 27
3.2.2 Technical Recommendations for Evaluating the Potential for Scaling (STEP 2) 29
3.2.3 Technical Recommendations for Selecting One or More Treatment Option(s) (STEP 3)
30
3.2.4 Technical Recommendations for Identifying Possible Limitations for Treatment
Options (STEP 4) 41
3.2.5 Technical Recommendations for Evaluating Feasibility and Cost (STEP 5) 44
3.3 Setting the Target Dose and Water Quality 44
3.3.1 pH/Alkalinity/DIC Adjustment 44
3.3.2 Phosphate-Based Inhibitors 46
3.3.3 Silicate Inhibitors 48
Chapter 4 : Review of Corrosion Control Treatment Steps under the LCR 49
4.1 Corrosion Control Treatment Steps for Systems Serving < 50,000 People 50
4.1.1 System Serving < 50,000 People Makes OCCT Recommendation (STEP 2) 52
4.1.2 Primacy Agency Determines Whether a Study Is Required for System Serving <
50,000 People (STEP 3) 52
4.1.3 Primacy Agency Designates OCCT for System Serving < 50,000 People (STEP 4) 53
4.1.4 System Serving < 50,000 People Conducts Corrosion Control Study (STEP 5) 54
4.1.5 Primacy Agency Designates OCCT for Systems Serving < 50,000 People (STEP 6) 61
4.2 Corrosion Control Steps for Systems Serving > 50,000 People 63
4.2.1 Systems Serving >50,000 People Conduct a Corrosion Control Study (STEP 1) 64
4.2.2 Primacy Agency Reviews the Study and Designates OCCT for System Serving > 50,000
People (STEP 2) 65
Chapter 5 : Requirements and Technical Recommendations for OCCT Start-Up and Monitoring
66
5.1CCT Start-up 66
5.1.1. Start-up of pH/Alkalinity/DIC Adjustment 67
5.1.2 Start-up of Phosphate-Based Corrosion Inhibitors 67
5.2 Follow-up Monitoring during First Year of Operation 67
5.2.1 Follow-up Lead and CopperTap Monitoring 68
5.2.2 Follow-up WQP Monitoring 68
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
5.3 Evaluating OCCT and Setting Optimal Water Quality Parameters 72
5.4 Required and Recommended Long-Term Corrosion Control Monitoring 73
Chapter 6 : Impacts of Source Water and Treatment Changes on Lead and Copper in Drinking
Water 75
6.1 Review of LCR Requirements Related to a Change in Source or Treatment 75
6.2 Impacts of Source Water Changes 76
6.3 Impacts of Treatment Changes 77
6.3.1 Corrosion Control Treatment 77
6.3.2 Disinfection 78
6.3.3 Coagulation 79
6.3.4 Water Softening 80
6.3.5 Filtration 80
Chapter 7 : References 81
Appendix A: Glossary
Appendix B: Estimated Dissolved Inorganic Carbon (mg/L as C) based on Alkalinity and pH (with
water temperature of 25 degrees C and TDS of 200)
Appendix C: Investigative Sampling to Determine the Source of Lead and Copper
Appendix D: Water Quality Data and Information Collection Forms
Appendix E: OCCT Recommendation Forms for Systems Serving < 50,000 People
Appendix F: Tools for Conducting Corrosion Control Studies
Appendix G: Forms for Follow-up Monitoring and Setting OWQPs
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
Exhibits
Exhibit 2.1: Timeline of Regulatory Actions Related to the Lead and Copper Rule 5
Exhibit 2.2: Typical Water Service Connection that May Provide Sources of Lead (Sandvig et al.,
2008) 11
Exhibit 2.3: Buffer Intensity as a Function of pH at Different DIC Values (Clement and Schock,
1998b, Figure 1) 15
Exhibit 2.4: Eh -pH Diagram for a Lead-Water-Carbonate System. DS oxidant demand in upper
box is 'distribution system oxidant demand' (Schock, 2007a; provided by author) 17
Exhibit 3.1: Typical Chemical Processes for pH/Alkalinity Adjustment 24
Exhibit 3.2: Theoretical Saturation pH for Calcium Carbonate Precipitation (USEPA, 2003) 30
Exhibit 3.3: Identifying the Appropriate Flowchart for Preliminary CCT Selection 31
Exhibit 4.1: Review of CCT Requirements and Deadlines for Systems Serving < 50,000 People
(§141.81(e)) 51
Exhibit 4.2: Recommended Checklist to Support Determination of the Need for a CCT Study for
Systems Serving < 50,000 People 53
Exhibit 4.3: Corrosion Control Study Requirements1 56
Exhibit 4.4: Recommended Checklist to Support Primacy Agency Determination of When to
Require a Desktop or Demonstration Study for Systems Serving < 50,000 People.. 57
Exhibit 4.5: Possible Outline for a Desktop Study Report 59
Exhibit 4.6: Possible Outline for a Demonstration Study Report 60
Exhibit 4.7: Recommendations for Primacy Agency Review of Desktop Study 61
Exhibit 4.8: Recommendations for Primacy Agency Review of Demonstration Study 62
Exhibit 4.9: Summary of CCT Requirements and Deadlines for Systems Serving > 50,000 People
(§141.81(e)) 63
Exhibit 5.1: Required Number of Sites for Follow-up Lead and CopperTap Monitoring 68
Exhibit 5.2: Follow-up WQP Monitoring Requirements1 and Recommendations 70
Exhibit 5.3: Required and Recommended Number of Sites for Follow-up WQP Tap Monitoring71
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems iv
-------
Flowcharts
Flowchart la: Selecting Treatment for Lead only or Lead and Copper with pH < 7.2 32
Flowchart Ib: Selecting Treatment for Lead only or Lead and Copper with pH from 7.2 to 7.8. 33
Flowchart Ic: Selecting Treatment for Lead only or Lead and Copper with pH > 7.8 to 9.5 34
Flowchart Id: Selecting Treatment for Lead only or Lead and Copper with pH > 9.5 35
Flowchart 2a: Selecting Treatment for Copper Only with pH < 7.2 36
Flowchart 2b: Selecting Treatment for Copper Only with pH from 7.2 to 7.8 37
Flowchart 2c: Selecting Treatment for Copper Only with pH > 7.8 38
Flowchart 3a: Selecting Treatment for Lead and/or Copper with Iron and Manganese in Finished
Waterand pH < 7.2 39
Flowchart 3b: Selecting Treatment for Lead and/or Copper with Iron and Manganese in Finished
Waterand pH > 7.2 40
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
Acronyms
AL Action Level
ANSI American National Standards Institute
AWWA American Water Works Association
CCPP Calcium Carbonate Precipitation Potential
CCT Corrosion Control Treatment
COC Chain of Custody
CSMR Chloride-to-Sulfate Mass Ratio
CWS Community Water System
DBP Disinfection Byproduct
DBPR Disinfection Byproducts Rule
DIC Dissolved Inorganic Carbon
DO Dissolved Oxygen
EDS Energy Dispersive Spectroscopy
EMF Electromotive Force
EPA Environmental Protection Agency
HAAS Haloacetic Acids
ICP-MS Inductively Coupled Plasma Mass Spectroscopy
LCR Lead and Copper Rule
LCR LTR Long-term Revisions to the Lead and Copper Rule
LSI Langelier Saturation Index
LSL Lead Service Line
LT2ESWTR Long Term 2 Enhanced Surface Water Treatment Rule
MCLG Maximum Contaminant Level Goal
MDBPR Microbial and Disinfection Byproducts Rules
NDWAC National Drinking Water Advisory Council
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems vi
-------
NOM
NPDWR
NSF
NTNCWS
OCCT
ORP
OWQP
POU
PWS
RLDWA
RTW
SDWA
SMCL
IDS
TTHM
VOC
WQP
WRF
WWTP
Natural Organic Matter
National Primary Drinking Water Regulations
NSF International
Non-transient, Non-Community Water System
Optimal Corrosion Control Treatment
Oxidation-Reduction Potential
Optimal Water Quality Parameters
Point-of-use
Public Water System
The Reduction of Lead in Drinking Water Act of 2011
Rothberg, Tamburini & Winsor Blending Application Package 4.0
Safe Drinking Water Act
Secondary Maximum Contaminant Level
Total Dissolved Solids
Total Trihalomethanes
Volatile Organic Compound
Water Quality Parameter
Water Research Foundation
Wastewater Treatment Plant
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
VII
-------
Chapter 1: Introduction
1.1 Purpose and Audience
The purpose of this document is to provide technical recommendations to help primacy
agencies and systems comply with corrosion control treatment (CCT) requirements of the Lead
and Copper Rule (LCR), including designation of Optimal Corrosion Control Treatment (OCCT).1
This document summarizes the regulatory requirements, and provides technical
recommendations that can assist systems in complying with CCT steps and assist primacy
agencies with evaluation of technical information from systems. It also includes background
information on corrosion and CCT techniques. This document provides Excel-based OCCT
Evaluation Templates that can be used to organize data and document decisions.
It is important to note that the technical recommendations in this document reflect the existing
LCR as of the date of document publication. The Environmental Protection Agency (EPA) is in
the process of reviewing CCT requirements as part of the Long-term Revisions to the Lead and
Copper Rule (LCR LTR). These requirements may change based on any final rule revisions that
are made. Readers can visit EPA's website for additional information and updates on the long-
term revisions: http://water.epa.gov/lawsregs/rulesregs/sdwa/lcr/index.cfm.
The technical recommendations provided in this document are consistent with corrosion
control guidance published by EPA (USEPA, 1992a; USEPA, 1997; and USEPA, 2003) and EPA
regulations, which were last updated in 2007. The technical recommendations in this document
reflect the latest science on lead and copper release and control based on new research and
additional LCR implementation experience. In particular, this document incorporates several
important new research findings, including:
• Influence of oxidation-reduction potential (ORP) on lead and copper release, and
importance of Pb(IV) compounds for systems with lead service lines (LSLs).
• Importance of aluminum, manganese, and other metals on formation of lead scales and
lead release.
• Impact of physical disturbances on lead release.
• Mechanisms and limitations of using blended phosphates for corrosion control.
• Target water quality parameters (WQPs) for controlling copper corrosion.
• Impacts of treatment changes, particularly disinfectant changes, on corrosion and
corrosion control.
1 Note that for the purposes of this document, "Optimal Corrosion Control Treatment" or "OCCT" is only used when referring to
the requirement in section 141.82(d) of the existing LCR for primacy agencies to designate optimal corrosion control treatment.
Section 141.2 defines optimal corrosion control treatment as "the corrosion control treatment that minimizes the lead and
copper concentrations at users' taps while insuring that the treatment does not cause the water system to violate any national
primary drinking water regulations." The terms "optimal" or "optimized" may also be used in the manual to indicate the best
conditions for preventing lead and copper from leaching into water.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
EPA recognizes that research is ongoing, and that the water industry's understanding of
corrosion, metals release, and treatment strategies will continue to evolve. EPA will update this
document periodically as new information becomes available and as time and resources allow.
1.2 Document Organization
The remainder of this document is organized as follows:
Chapter 2: Background Information provides a history of regulatory actions to reduce lead and
copper exposure from drinking water, including efforts since the 1986 Safe Drinking Water Act
(SDWA) Amendments to limit the amount of lead in plumbing materials. It also describes the
sources of lead in water, including an overview of lead and copper corrosion and release
mechanisms, and relative contribution of lead- and copper-containing materials. Lastly, this
chapter provides an updated description of water quality and physical factors that influence
lead and copper levels in drinking water.
ChapterS: Corrosion Control Treatment for Lead and Copper describes the available CCT
methods and provides approaches that can be used to identify CCT alternatives. The chapter
also provides technical recommendations on setting treatment dose and water quality
conditions.
Chapter 4: Corrosion Control Treatment Steps under the LCR reviews the CCT requirements
under the LCR and provides additional technical recommendations for primacy agencies and
systems to consider when meeting these requirements.
Chapter 5: OCCT Start-Up and Monitoring provides technical recommendations on CCT start-
up, reviews requirements under the LCR and technical recommendations for follow-up
monitoring during the first year of CCT implementation, reviews requirements for establishing
optimal water quality parameters (OWQPs) under the LCR, and reviews LCR- required WQP and
technical recommendations for additional corrosion control monitoring.
Chapter 6: Impacts of Source Water and Treatment Changes on Lead and Copper in Drinking
Water reviews the requirements in the LCR for notification and approval of a source or
treatment change. The chapter also provides technical information on how source and
treatment changes can affect lead and copper release.
Chapter 7: References provides a full list of references that were used in the development of
this document.
These chapters are supported by several appendices:
Appendix A provides a glossary of corrosion terms.
Appendix B provides lookup tables for systems to determine dissolved inorganic carbon (DIC)
based on pH and alkalinity.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
Appendix C provides technical recommendations on how to conduct investigative sampling and
construct lead profiles to help identify the sources of lead and copper in a building water
system.
Appendix D provides blank forms for data collection to support a system's OCCT
recommendation and/or the corrosion control study.
Appendix E provides blank forms for systems to support OCCT recommendations to their
primacy agencies.
Appendix F summarizes desktop and demonstration tools that can be used by systems when
conducting a corrosion control study.
Appendix G provides blank forms for systems and technical recommendations for primacy
agencies when reviewing system data and designating OWQPs.
1.3 How to Use this Document
Primacy agencies and systems can use the material in Chapters 2 and 3 as a technical reference
to help understand corrosion and CCT and to evaluate CCT alternatives. Chapters 4 and 5
provide a review of the LCR regulatory requirements and provide additional technical
recommendations to support primacy agencies and systems when a system serving 50,000 or
fewer people exceeds the lead or copper action level (AL), or if a system increases its
population to more than 50,000 and is subject to the CCT requirements of the LCR for the first
time. Chapters 4 and 5 can also be useful for systems serving more than 50,000 people that
previously installed CCT but have subsequent AL exceedances. Primacy agencies and systems
can use the information in Chapter 6 to review the regulatory requirements related to
notification and approval of a source or treatment change. They can also use the technical
information in this chapter to determine how treatment changes could impact lead and copper
release.
The Excel-based OCCT evaluation templates mirror the steps and tables in Chapters 4 and 5
and Appendices D through G. Primacy agencies can use the templates to document
circumstances around an AL exceedance and review compliance deadlines for individual
systems. They can also use the templates to support determinations of whether or not to
require a CCT study, what kind of study to require, and to document their decisions. The
templates provide electronic versions of the forms in Appendices D through G. Systems can use
the forms to organize their data and information electronically and prepare submittals to their
primacy agencies.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
Chapter 2: Background Information
This chapter provides information on:
• Regulations to control lead and copper in drinking water;
• Sources of lead and copper;
• Water quality characteristics that impact corrosion of lead and copper and release of
these metals into the water; and
• Physical and hydraulic characteristics of water systems that impact lead and copper
release.
2.1 Regulatory Actions to Control Lead and Copper in Drinking Water
2.1.1 Lead and Copper Regulation
The national primary drinking water regulation that controls lead and copper in drinking water
is the 1991 Lead and Copper Rule (LCR) (USEPA, 1991a), as amended. In the 1991 rulemaking,
the Environmental Protection Agency (EPA) established maximum contaminant level goals
(MCLGs) (zero for lead and 1.3 milligrams per liter (mg/L) for copper) and action levels (0.015
mg/L for lead and 1.3 mg/L for copper) in public water systems (PWSs). (See Exhibit 2.1 for a
timeline of Lead and Copper regulations and related regulatory activities.) The lead or copper
action level is exceeded if the concentration in more than 10 percent of water samples (i.e., the
90th percentile level) collected after a minimum stagnation period of 6 hours is greater than the
respective action level. Samples from residences must be collected from cold water kitchen or
bath taps and those collected from non-residential areas must be collected from interior taps
(§141.86(b)(2)).2 The number of samples to be collected depends on the size of the water
system, as specified in the regulation. The 1991 LCR also established requirements that are
triggered, in some instances, by exceedances of the action levels. These additional
requirements include the installation and maintenance of corrosion control treatment (CCT)
and source water monitoring/treatment, lead public education, and lead service line (LSL)
replacement.
2 Unless otherwise stated, all citations are in Title 40 of the Code of Federal Regulations (CFR).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
June 1991
Original LCR promulgated
January 2000
LCR Minor Revisions promulgated
2017
LCR Long-Term Revisions (projected)
June 1986
SDWA Amendments signed
August 1996
SDWA Amendments signed
August 1988
Deadline to meet lead ban
August 1998
Deadline to
meet new
"lead-free"
definition
October 2007
LCR Short-Term Revisions promulgated
January 2011
Reduction of Lead
in Drinking Water
Act (RLDWA)
signed
January 2014
. RLDWA takes effect
December 2013
Community Fire Safety Act signed
Exhibit 2.1: Timeline of Regulatory Actions Related to the Lead and Copper Rule
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
After the June 1991 LCR, EPA promulgated several technical amendments (USEPA, 1991b;
USEPA, 1992b; USEPA, 1994; USEPA, 2004c) as well as more extensive revisions in January 2000
and October 2007 (USEPA, 2000; USEPA, 2007a). The goal of the January 2000 LCR Minor
Revisions was to streamline requirements, promote consistent national implementation, and, in
many cases, reduce monitoring and reporting requirements (USEPA, 2000). The goal of the
2007 LCR Short-Term Revisions was to enhance the implementation of the LCR in the areas of
monitoring, treatment, consumer awareness, and LSL replacement, as well as to improve
compliance with the public education requirements of the LCR (USEPA, 2007a).
EPA has continued to work on the long-term issues identified in EPA's 2005 Drinking Water
Lead Reduction Plan (USEPA, 2005) and the 2007 rule revisions. This effort is referred to as the
Long-term Revisions to the Lead and Copper Rule (LCR LTR). EPA's primary goal for the LCR LTR
is to improve the effectiveness of CCT in reducing exposure to lead and copper and to trigger
additional actions that equitably reduce the public's exposure to lead and copper when CCT
alone is not effective. While not including all potential revisions to the LCR, key categories
where revisions are being considered are:
• Sample site selection criteria for lead and copper.
• Lead sampling protocols.
• Public education for copper.
• Measures to ensure optimal corrosion control treatment (OCCT).
• LSL replacement.
EPA convened a National Drinking Water Advisory Council (NDWAC) Working Group to provide
advice to the NDWAC on these five key categories and other important issues related to the
LCR LTR. The Working Group presented its recommendations to the NDWAC in November 2015
(http://www.epa.gov/ndwac/letters-recommendations-epa-administrator-ndwac). The NDWAC
is a chartered federal committee that considered the recommendations made by the Working
Group and forwarded its recommendations to EPA in December 2015. See EPA's LCR home
page for updates on the LCR LTR: http://water.epa.gov/lawsregs/rulesregs/sdwa/lcr/index.cfm.
2.1.2 Control of Lead Content in Plumbing Components
While the LCR regulates the amount of lead and copper in drinking water, the Safe Drinking
Water Act (SDWA) also includes provisions aimed at reducing the amount of lead in plumbing
components, which could result in lower lead levels in tap samples in the future. This section
discusses key changes in SDWA to reduce lead in plumbing components. For additional
information, see the references and web links provided herein.
The 1986 SDWA Amendments established requirements to minimize the lead content in source
materials that are used in the conveyance and treatment of drinking water. Section 1417 of the
1986 SDWA Amendments banned the use of lead pipe and required the use of "lead-free"
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
solders, fluxes, pipes and pipe fittings in the installation or repair of PWSs (also referred to as
the "lead ban") (USEPA, 1987). Lead-free materials were defined as:
• Solders and fluxes with a lead content of < 0.2 percent.
• Pipes and pipe fittings with a lead content of < 8.0 percent.
The 1996 SDWA Amendments made it unlawful for anyone to introduce into commerce pipes,
pipe or plumbing fittings or fixtures that are not lead free. The 1996 Amendments also required
certain plumbing fittings and fixtures (endpoint devices) to be in compliance with a
performance standard for lead release for plumbing fittings and fixtures.3 This standard was
satisfied by NSF International/American National Standards Institute (NSF/ANSI) Standard 61,
Section 9,4 which limited the amount of lead that can be leached from endpoint devices used
for water intended for human consumption. After August 6, 1998, only those plumbing fittings
and fixtures with a lead content of < 8.0 percent that were in compliance with NSF/ANSI
Standard 61, Section 9 by an ANSI-accredited certifier could be defined as "lead-free" (NSF,
2010).5
Plumbing materials meeting the lead-free definition of < 8.0 percent lead were still found to
contribute to lead levels measured at the tap (Sandvig et al., 2008). Thus, efforts to reduce the
lead content of materials continued, notably in the States of California, Maryland,
Massachusetts, and Vermont. In response, manufacturers developed non-leaded alloys
containing very low levels of lead (less than 0.25 percent lead) that can be used in the
manufacture of brass faucets, meters, and fittings. Many utilities have also developed their own
specifications for non-leaded components (Sandvig et al., 2007).
In 2011, The Reduction of Lead in Drinking Water Act of 2011 (RLDWA) revised Section 1417 to:
(1) Redefine "lead-free" in SDWA Section 1417(d) to:
• Lower the maximum lead content of the wetted surfaces of plumbing products
such as pipes, pipe fittings, plumbing fittings and fixtures from 8.0% to a
weighted average of 0.25%;
• Establish a statutory method for the calculation of lead content; and
• Eliminate the requirement that lead-free products be in compliance with
voluntary standards established in accordance with SDWA 1417(e) for leaching
of lead from new plumbing fittings and fixtures.
3 For a summary of the 1996 Amendments revisions to the lead ban, refer to Section 118. https://www.congress.gov/bill/104th-
congress/senate-bill/1316.
4 Devices specifically listed in NSF Standard 61, Section 9 include kitchen and bar faucets, lavatory faucets, water dispensers,
drinking fountains, water coolers, glass fillers, residential refrigerator ice makers, supply stops and endpoint control valves.
Devices that were not covered by section 9 of NSF 61 were not subject to the NSF performance-based standard, but if they
were covered by Section 1417, they were subject to the 8.0 percent lead limit.
5 This commerce restriction does not apply to pipe used for manufacturing and industrial processing.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
(2) Create exemptions in SDWA Section 1417(a)(4) from the prohibitions on the use or
introduction into commerce for:
• Pipes, fittings and fixtures that are used exclusively for nonpotable services
where the water is not anticipated to be used for human consumption (SDWA
1417(a)(4)(A)); and
• "toilets, bidets, urinals, fill valves, flushometer valves, tub fillers, shower valves,
service saddles, or water distribution main gate valves that are 2 inches in
diameter or larger." (SDWA 1417(a)(4)(B)).
A subsequent Act, The Community Fire Safety Act of 2013, signed on December 20, 2013,
exempted fire hydrants from the new lead-free standard, and required EPA to consult with the
NDWAC on lead-free issues. Both The RLDWA and Community Fire Safety Act became effective
on January 4, 2014. EPA has published a "Summary of The Reduction of Lead In Drinking Water
Act and Frequently Asked Questions" that describes both of these Acts in more detail (USEPA,
2013b).6 EPA is developing a proposed rule to reflect the changes to Section 1417 of SDWA as a
result of the RLDWA and to assist in implementation, which, when finalized, will revise §141.43
- Prohibition of Use of Lead Pipes, Solder, and Flux.
Although the SDWA no longer requires third-party certification, some state or local laws require
third-party certification. In addition, third-party certification bodies or agencies may be used by
manufacturers to inform consumers which products meet a voluntary standard. One such
standard, NSF/ANSI 372 is consistent with the requirements of the RLDWA. A third-party
certification against this standard could be a useful way to identify a product as meeting the
requirements of Section 1417. Products will bear the mark of the laboratory that has
independently certified the product as meeting the standard. EPA published a brochure to help
the public identify the various marks that indicate a product has been certified as lead-free to
satisfy the new requirement of the Act: "How to Identify Lead-Free Certification Marks for
Drinking Water System & Plumbing Materials" (USEPA, 2015a).7 EPA also recommends that
PWSs incorporate this NSF/ANSI standard into their contract specifications for materials
installed in their treatment and distribution systems, and to encourage their consumers to
purchase certified products.
2.2 Sources of Lead and Copper
Lead and copper are rarely present in raw water sources. They are primarily present at the
customer's tap due to corrosion of lead and copper-based material. This section:
• Provides an overview of chemical and physical reactions that result in lead and copper
release into drinking water (Section 2.2.1); and
6 This document is available at http://water.epa.gov/drink/info/lead/upload/epa815sl3001.pdf.
7 This document is available at http://nepis.epa.gov/Exe/ZvPDF.cgi?Dockev=P100LVYK.txt.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
• Discusses the relative contribution from supply lines and premise plumbing components
(Section 2.2.2).
2.2.1 Corrosion and Metals Release
Corrosion in water systems is defined as the electrochemical interaction between a metal
surface such as pipe wall or solder and water. During this interaction, metal is oxidized and
transferred to the water or to another location on the surface as a metal ion. Depending on the
material there are many forms of corrosion, but usually the most important for drinking water
are: (1) uniform corrosion, where the electrochemical interaction occurs along the pipe wall,
resulting in a relatively uniform loss of metal across the entire surface; (2) non-uniform
corrosion, where metal is lost from a localized point, causing pitting and mounding in some
cases; and (3) galvanic corrosion which comes from a coupling of dissimilar metals or internally
in metallic alloys. While it is important to understand and control corrosion, the LCR is
specifically concerned with controlling metals release (i.e., release of lead and copper) into the
water. Metals release is a function of the reactions that occur between the metal ions released
due to corrosion, and the physical, chemical, and biological characteristics of the water and the
metal surface.
The form of lead and copper released into the water can be dissolved, colloidal, or particulate
(i.e., bound up with other compounds such as iron and aluminum). Of great importance is the
scale that builds up naturally on the metal surface. Pipe scales can be complex and can include
two types of compounds: (1) passivating films that form when pipe material and water react
directly with each other; and (2) deposited scale material that forms when substances in the
water (e.g., iron, manganese, aluminum, calcium) precipitate out or sorb to, and then build up
on the pipe surface. Scales can have layers and are influenced by treatment history. The
structure and compounds in the existing corrosion scale can influence the effectiveness of CCT.
Researchers have identified many different compounds on lead pipe scales depending on water
quality and treatment history:
• In the absence of corrosion inhibitors, lead pipe scales are frequently dominated by
compounds that result from the reaction of carbonate and divalent lead compounds
(Pb++ or Pb(ll)),8 such as hydrocerussite [(Pb3(C03)2(OH)2] and cerussite (PbC03) (Schock
and Lytle, 2011). Plumbonacrite (Pbio(C03)6(OH)60) has been found to co-occur with
Pb(ll) carbonate compounds in scales and can be a predominant form in systems with
high pH (>10) (DeSantis and Schock, 2014). Lead pipe scales may also include massicot
and litharge (which are both forms of PbO) under higher alkalinity conditions (McNeill
8 Pb++, Pb(ll), or divalent lead is the ionic form of lead that is transferred from the material to the water during the corrosion
process.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
-------
and Edwards, 2004). Carbonate containing scales are often off-white and slightly chalky
when dry (Schock and Lytle, 2011).
• Newer research has confirmed that Pb(IV) compounds, i.e., lead oxide (PbCh),9 can be
the predominant compounds in lead pipe scales under highly oxidative conditions10 and
under low organic matter conditions (Schock, 2007b, Schock, 2001, Schock and Giani,
2004; DeSantis and Schock, 2014).
• When orthophosphate is used, lead pipe scales are often dominated by crystalline Pb(ll)
orthophosphate compounds such as hydroxypyromorphite, Pbg(P04)6, or Pbs(P04)2.
Scales in systems with blended phosphates do not follow the same trends as
orthophosphate and seem to be influenced by calcium concentrations and phosphorus
speciation (DeSantis and Schock, 2014).
Copper-based scales usually include cuprite (Cu20), cupric hydroxide (Cu(OH)2), tenorite (CuO),
and malachite (Cu2(OH)2COs). When orthophosphate is used, various copper phosphate scales
may develop (Schock and Sandvig, 2006; Schock and Lytle, 2011)).
The characteristics of the scale and its structure dictate the amount of lead or copper that is
released into the water. If conditions favor the formation of insoluble, adherent scale (i.e., scale
that adheres well to the pipe wall), the rate of metals release will be low. However, if scales do
not adhere well to the pipe wall or they are very soluble, the release of metals may be greater.
Other compounds in the water including aluminum, iron, manganese, and calcium can
significantly influence scale formation and properties. The type of scale will also dictate how
susceptible it is to releasing particulate lead following physical disturbances (e.g., infrastructure
work).
2.2.2 Lead and Copper-Containing Material
The main sources of lead and copper in drinking water are the materials used for supply pipes
from the water main to the building (also called "service lines") and premise plumbing. These
include lead and copper pipe, lead-based solder, and brass materials used in faucets and
fittings.11 Exhibit 2.2 shows plumbing components that may be potential sources of lead.12
9 Pb""1"1-, Pb(IV), or tetravalent lead is an ionic form of lead that forms lead oxide (Pb02), the only Pb(IV) compound that has
been identified in lead pipe scales. Throughout this manual, Pb(IV) and Pb(C>2) are used interchangeably.
10 For example, systems that have a free chlorine residual of 2 mg/L or greater. See Section 2.3 for more information on how
disinfection affects ORP of the water and how this affects the types of lead compounds in the scale.
11 Prior to the 1986 SDWA Amendments, 50:50 lead:tin solder could be used for potable applications. Brass alloys comprised of
various amounts of copper and lead are used to manufacture pipes, pipe fittings, plumbing fittings, and fixtures (e.g., faucets
and meters. As discussed in Section 2.1.2. The RLDWA of 2011 further limits the allowable lead content of these materials.
12 Although the water utility often owns the portion of the supply pipe from the water main to the property boundary, the
homeowner generally owns the portion from the property boundary or meter to the home and is responsible for premise
plumbing. This makes lead and copper unique contaminants in that their source is under the control of the individual customer
(except in the case of the portion of a LSI owned by the water utility).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 10
-------
Researchers have performed various studies to identify the relative contribution of these
materials to lead and/or copper levels measured at the tap in standing samples (Gardels and
Sorg, 1989; Lytle and Schock, 1996; Kimbrough, 2001; Kimbrough, 2007; Sandvig et al., 2008;
Kimbrough, 2009). They have found that LSLs contribute a significant percentage of the lead in
samples collected at the tap (under normal household usage conditions), and that brass may
also be a significant source of lead and copper depending on the quality of the drinking water
and the composition of and manufacturing process for the brass faucet or fitting. There are,
however, many different types of alloys used in brass faucets and fittings. Each may react
differently under different water qualities and chemistries, as well as water use patterns, which
makes it difficult to identify specific brass components that might cause problems with respect
to lead and/or copper release in any given PWS. Appendix C provides methods for diagnostic
monitoring that can help pinpoint the source of lead for a specific building.
Property
Boundary
Internal
Plumbing
Water
Meter
Water,
Main
Gooseneck or pigtail
Exhibit 2.2: Typical Water Service Connection that May Provide Sources of Lead (Sandvig et
al., 2008)
Copper pipe may be used for both the supply pipe (service line) and the interior piping. Brass
fixtures typically are 60 - 90 % copper by weight. Copper release depends on water quality
conditions (particularly pH, dissolved inorganic carbon (DIC), and oxidation-reduction potential
(ORP)), the age of the copper pipe, and how long the water has been in contact with the pipe.
Copper release is typically higher in newer copper plumbing (Cantor et al., 2000; Kimbrough,
2007; Schock and Lytle, 2011). The amount of time required for copper pipes to passivate (i.e.,
no longer release copper into the water) is highly dependent on water quality particularly pH,
alkalinity, and DIC.
New research has shown that iron and manganese can adsorb other metals such as lead.
McFadden et al. (2011) showed that lead released from LSLs was adsorbed onto galvanized iron
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
11
-------
pipe in homes. Another study showed that iron- and manganese- rich scale provided a source of
lead for more than four years after LSLs were fully removed (Schock, Cantor, et al., 2014). Thus,
lead released "upstream" (e.g., from an LSI) can accumulate in these scales, providing a long-
term source of lead even after LSLs and other lead-containing materials are removed. Residual
aluminum in the finished water from the coagulation treatment step can also affect the type
and stability of scales formed within LSLs (Schock, 2007b).
2.3 Water Quality Factors Affecting Release of Lead and Copper
New research conducted in recent years has continued to show the influence and importance
of water quality on lead and copper levels in drinking water. Water quality can affect the rate of
corrosion of lead and copper materials, the formation and characteristics of scales that form on
lead and copper based materials, and ultimately, the release of metals into the water. New
findings have shed light on the effects on lead and copper levels of natural organic matter
(NOM) and metals including iron, aluminum and manganese. Alkalinity, pH, DIG, and corrosion
inhibitors remain critical parameters that directly impact lead release. In addition, new research
has shown the importance of ORP in certain types of waters.
Understanding the water quality conditions that impact the release of lead and copper in
drinking water provides a foundation for making effective treatment decisions. This section
describes the following parameters, how they can be measured or approximated, and how they
can affect lead and copper release in drinking water:
• Alkalinity, pH, and DIG.
• Corrosion inhibitors.
• Hardness (calcium and magnesium).
• Buffer Intensity.
• Dissolved oxygen (DO).
• Oxidation reduction potential (ORP).
• Ammonia, chloride, and sulfate.
• Natural organic matter (NOM).
• Iron, aluminum, and manganese.
2.3.1 pH, Alkalinity and DIG
The pH of water is a measure of its acidity, otherwise known as its hydrogen ion concentration
(H+or HsO+). Alkalinity is the capacity of water to neutralize acid. It is primarily the sum of
carbonate, bicarbonate, and hydroxide anions in the water as shown in Equation 1 (Stumm and
Morgan, 1981).
Alkalinity = 2C032"+ HC03"+ OH'- H+ Equation 1
DIG is an estimate of the total amount of inorganic carbon as shown in Equation 2 (Stumm and
Morgan, 1981).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 12
-------
DIG = C02 + H2C03 + C032- + HC03- Equation 2
Alkalinity and DIG are closely related. Most alkalinity comes from bicarbonate and carbonate
ions in the water. Although water operators are more familiar with alkalinity, DIG is the
parameter more closely related to corrosion because it directly measures the available
carbonate species in the water that can react with lead and copper to form the passivating
scales. The water's pH influences many other corrosion-related parameters (i.e., buffer
capacity, alkalinity, ORP) and has a large influence on corrosion inhibitor effectiveness.
It is best to measure pH in the field at the time of sample collection using a calibrated
instrument. EPA Method 150.1 emphasizes the importance of proper sampling technique - the
pH of highly purified waters and the pH of waters that are not in equilibrium with the
atmosphere are subject to changes as dissolved gases are either absorbed or desorbed. To
minimize these impacts, EPA recommends filling sampling containers completely and keeping
them sealed prior to analysis (USEPA, 1982). Alkalinity is commonly measured by a certified
laboratory and reported as mg/L as calcium carbonate (CaCOs). DIG cannot be measured but
can be predicted based on the pH, alkalinity, ionic strength and temperature of the water, using
the tables in Appendix B. DIG is usually reported in mg/L as carbon (mg/L as C).There are
optimal ranges of pH and DIG that result in the greatest formation of insoluble compounds in
the scale, and in this way prevent the release of lead and copper. See Chapter 3 for technical
recommendations on adjusting pH/alkalinity/DIC to prevent lead and copper release.
The pH, alkalinity, and DIG of water can be highly variable within the distribution system. The
pH can fluctuate due to interactions between water and pipe material, microbiological activity,
and changes in disinfectant residual. The water's ability to resist changes in pH is called its
buffering capacity (also called buffer intensity). The carbonate and bicarbonate ions in the
water provide this buffering; see Section 2.3.4 for additional information.
Regardless of the specific treatment used, understanding the pH and DIG range throughout a
distribution system is an important part of maintaining corrosion control and minimizing the
release of lead and copper.
2.3.2 Corrosion Inhibitors
Corrosion inhibitors are used not only to control lead and copper release, but also to prevent
corrosion of iron pipe and other metals in the distribution system. The most common corrosion
inhibitors used by water systems are phosphate-based, which means they have
orthophosphate (PC>43~) in their formulation. Silicate-based corrosion inhibitors, which are
mixtures of soda ash and silicon dioxide, have been used in a few cases.
Orthophosphate is commonly used for lead and copper control. Polyphosphates, which are
polymers containing linked orthophosphate ions in various structures are used mainly for
sequestering iron and manganese. They work by binding or coordinating the metals into their
structures so they cannot precipitate on sinks or clothes. Polyphosphates can also sequester
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 13
-------
lead and copper, keeping them in the water and actually increasing the risk of exposure.
Polyphosphates can revert to orthophosphate in the distribution system, but it is difficult to
predict if and when this occurs. Research has confirmed that polyphosphates are generally not
effective on their own for controlling the release of lead and copper (Holm and Schock, 1991;
Cook, 1992; Dodrill and Edwards, 1995; Cantor et al., 2000). Blended phosphates, which contain
a mixture of orthophosphate and polyphosphate, have been used for corrosion control and to
sequester iron and manganese. Silicate-based inhibitors have been shown to successfully
reduce lead and copper levels in first draw-samples at the tap (Schock, Lytle, et al., 2005), but
their full-scale use has been limited.
See Chapter 3 for additional technical recommendations on using orthophosphate, blended
phosphates, and silicate-based corrosion inhibitors for controlling lead and copper release.
2.3.3 Hardness (Calcium and Magnesium)
Hardness is primarily the sum of calcium and magnesium in water. It is a common water quality
parameter measured in the laboratory and is typically reported as mg/L as CaCOs (calcium
carbonate).
If finished water has high hardness, increasing the pH to control lead release can cause calcium
carbonate precipitation, or scaling, in the distribution system. The Langelier Saturation Index
(LSI), and other calcium carbonate-related indices such as the Ryznar Index and calcium
carbonate precipitation potential (CCPP), can be used as indicators of scaling conditions (Schock
and Lytle, 2011).13 It is important that the LSI and other CaCOs related indices not be used to
evaluate lead or copper control. The LSI is only important insofar as it provides information
regarding the amount of pH adjustment that can be employed without causing precipitation.
In addition to contributing to scaling, calcium may be a particularly important component of
scales laid down by blended phosphate corrosion inhibitors. See Chapter 3 for more
information.
2.3.4 Buffer Intensity
Buffer intensity (also called buffer capacity) is a measure of the water's resistance to changes in
pH, either up or down. It is defined as the concentration of base required to raise the pH one
unit and has units of moles/L/unit pH. Buffer intensity depends on the alkalinity, DIC, and pH of
the water. Exhibit 2.3 shows the relationship of pH and buffer intensity at different DIC values,
with the highest buffer intensity at a pH of approximately 6.3 and minimum intensity at pH
values between 8.0 and 8.5. Thus, waters with pH between 8 and 8.5 and low DIC (less than
about 10 mg/L as C) have low buffer intensity and may have more variable pH within the
distribution system, whereas waters outside this pH range will have higher buffer intensity and
may exhibit less variability in pH levels in the distribution system. Increasing DIC in waters with
13The LSI is defined as the comparison between the measured pH of the water with the pH the water would have at saturation
with CaC03.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 14
-------
pH values in the 8 - 8.5 range will not result in appreciable increases in buffer intensity.
Additional buffer intensity may result when phosphate or silicate chemicals are dosed at a high
concentration relative to DIG.
DIC=2
DIC=5
DIC=10
DIC=30
DIC=50
6
i
7
i
8
PH
9
10
Exhibit 2.3: Buffer Intensity as a Function of pH at Different DIG Values (Clement and Schock,
1998b, Figure 1)
2.3.5 Dissolved Oxygen
Oxygen is slightly soluble in water, seldom reaching dissolved concentrations above 15 mg/L. In
ground water, DO can vary depending on the geochemistry and hydrogeology of the aquifer.
Deep ground water or shallow ground water in areas where the recharge area has silty or
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
15
-------
clayey soils may have no DO. Shallow ground water in areas with fractured rock or sandy soils
may contain higher concentrations of DO. Surface waters are generally more oxygenated,
especially flowing sources (i.e., rivers). Stagnant water and waters with high DO content,
however, can create oxygen-deficient conditions in some cases. The DO concentration depends
on water temperature, but typical well-aerated water will have a DO concentration of about 8
or 9 mg/L. DO concentrations can be measured in the field using a calibrated DO meter.
DO concentration affects the solubility of iron, manganese, lead, and copper. Some ground
water systems add dissolved oxygen through aeration processes to oxidize iron and manganese
so that they can be removed through precipitation. Increasing DO in the water can increase
copper corrosion, converting Cu(l) to Cu(ll). However, water with high DO levels may provide
corrosion benefits under some circumstances, by facilitating the production of different and
more protective lead oxide scales than would have been formed under low DO conditions (see
Section 2.3.6 on Oxidation-Reduction Potential for more information).
2.3.6 Oxidation-Reduction Potential
Oxidation-reduction potential, also called redox potential or ORP, is the electric potential
required to transfer electrons from one compound (the oxidant) to another compound (the
reductant). It is considered a quantitative measure of the state of oxidation in water treatment
and distribution systems. Like pH, ORP is a fundamental characteristic of aqueous systems and
affects how water interacts with solid substances such as metal pipe material. It is commonly
measured using a platinum reference electrode and reported in units of volts (V) or millivolts
(mV). Measured ORP values are often normalized with respect to the standard hydrogen
electrode and reported as electric potential (Eh) by taking into account a material-specific
conversion factor, generally provided by the electrode manufacturer or found in reference
textbooks (Copeland and Lytle, 2014).
ORP varies with pH, temperature, and DIG, but is fundamentally driven by the type and
concentration of disinfectant in the water (e.g., chlorine or chloramines) and the DO
concentration. Laboratory studies by James et al. (2004) and Copeland and Lytle (2014) showed
that ORP values are highest for free chlorine and chlorine dioxide, and that ORP decreases with
increasing pH from 7 to 9, regardless of the oxidant used. Copeland and Lytle (2014) found an
Eh range of 0.51 V (no disinfectant and pH of 9) to 1.02 V (chlorine disinfection and a pH of 7). In
general, the influence of free chlorine on ORP is much greater than that of DO. As a result, for
systems using a free chlorine residual in the distribution system, DO's influences on ORP are
minor.
Under certain conditions, ORP can have a dramatic impact on lead release. Exhibit 2.4 shows
the theoretical Eh and pH conditions that favor different dissolved and solid forms of lead. The
hatched areas represent lead solids, and the un-hatched areas are lead complexes that are in
solution. It is important to note that Eh -pH diagrams are based on theory, and the positions of
the boundaries can vary depending upon the data used to construct them. Thus, these
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 16
-------
diagrams should be used to understand relationships and interpret field data, and not for
predicting lead release.
Exhibit 2.4 shows that Pb(ll) solids exist theoretically at low Eh values at typical pH levels in
drinking water. At higher Eh values (> 0.7 V) and in the absence of corrosion inhibitors or other
interfering surface deposits, PbCh (a Pb(IV) solid) could form on lead pipe surfaces. PbCh is
insoluble and would prevent lead from being released to the water. Water quality changes that
cause a reduction in pH or ORP from a change in disinfection practices (e.g., switching from
chlorine to chloramines in the distribution system), however, can cause PbChto convert to
Pb(ll) compounds and release lead into the water.
The high Eh values needed for PbCh formation may be found in systems that have a high
chlorine residual (i.e., > 2 mg/L as free chlorine) for extended periods of time. PbCh has been
observed to form between pH 7 and 9.5, with formation occurring more quickly at higher pH
values. Field testing has shown that the amount of lead released from PbCh scales is very low
and close to lead levels for non-lead pipes (Schock, Triantafyllidou, et al., 2014).
EMF-pH Diagram for Pb - Hp - CO-System
- (UMS mg/L; BC - « mg CA.
IHK3TC
GT
£
9
1.50
1.00
0.50 -
0.00
-0.50
-1.00
•1.60
Drop in ORP from
treatment change of
DS oxidant demand
Drop in pH at surface
from treatment change,
rxns, nitrification, etc.
10 11 12 13 14
Exhibit 2.4: Eh -pH Diagram for a Lead-Water-Carbonate System. DS oxidant demand in upper
box is 'distribution system oxidant demand' (Schock, 2007a; provided by author)
2.3.7 Ammonia, Chloride, and Sulfate
Excess ammonia (NHs) may occur in the distribution system due to elevated source water
ammonia levels and/or if the system uses chloramines for disinfection. The presence of excess
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
17
-------
ammonia can lead to nitrification in the distribution system. Nitrification occurs when nitrifying
bacteria convert ammonia into nitrite and nitrate, which may lower the pH and alkalinity of the
water. This can accelerate brass corrosion and cause problems with lead release (Uchida and
Okuwaki, 1999; Douglas et al., 2004). Ammonia may also form compounds with lead and
copper, which can interfere with the effectiveness of CCT.
Research has shown that the ratio of chloride (Cl~) to sulfate (S042~) in the water can be an
indicator of potential lead release. An evaluation of LCR tap sampling data from 12 drinking
water utilities collected as part of a Water Research Foundation (WRF) project found that all of
the water systems with chloride-to-sulfate ratios less than 0.58 met the 90th percentile action
level for lead, whereas only 40 percent of the systems with chloride/sulfate ratios greater than
0.58 met the lead action level (Reiber et al., 1997). More recent research has shown that that
lead leaching increased when the chloride-to-sulfate mass ratio approached 0.4 to 0.6 (Nguyen
et al., 2010; Nguyen et al., 2011); however, further increasing the chloride-to-sulfate mass ratio
above 0.7 may not necessarily be an indicator of increased lead release (Wang et al., 2013).
Lower chloride-to-sulfate ratios may be indicative of lower lead release due to the formation of
an insoluble sulfate precipitate with lead. Higher ratios may result in the formation of a soluble
chloride complex, where lead is galvanically connected to another metal such as copper
(Nguyen etal., 2010; 2011).
The chloride and sulfate content in water can change with a switch from sulfate-based
coagulants (such as aluminum sulfate (alum) and ferric sulfate) to chloride-based coagulants
(such as ferric chloride). Conversely, a change from ferric chloride to alum may increase the
sulfate content in the water, potentially reducing lead release. Other scenarios that may affect
lead release by altering the chloride and sulfate concentration in the water (and hence the
chloride-to-sulfate mass ratios) include blending of desalinated seawater, using anion
exchange, or brine leaks from on-site hypochlorite generators (Nguyen et al., 2010; 2011).
Galvanic connections and galvanic corrosion can occur in the distribution system with the use of
lead solder on copper pipes, or from partial lead line replacements (Oliphant, 1983; Gregory,
1985; Reiber, 1991; Singley, 1994; Lauer, 2005, Nguyen et al., 2010; Triantafyllidou and
Edwards, 2011; Clark et al., 2013; Wang et al., 2013).
2.3.8 Natural Organic Matter
NOM is a complex mixture of organic compounds that occur in both ground and surface water
sources, but are more prevalent in surface water. NOM is difficult to measure, so utilities often
use UV254 (specific absorption, the ratio of UV absorption to organic carbon concentration) as a
surrogate (APHA, AWWA, and WEF, 2005).
The impact of NOM on metals release is unclear. NOM in finished water can help form the
protective films that reduce corrosion, but it has also been shown to react with corrosion
products to form soluble complexes with lead, which may increase lead levels in the water
(Korshin et al., 1996,1999, 2000, 2005). Organic matter can also provide nutrients for
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 18
-------
microorganisms, exacerbating problems with biofilm growth and depleting chlorine residuals.
This additional microbial growth can cause microbially-induced copper corrosion (pinhole leaks)
through localized decreases in pH or, in the case of sulfate-reducing bacteria, through the
formation of sulfide (Schock and Lytle, 2011).
2.3.9 Iron, Manganese, and Aluminum
Iron and manganese are present in many ground water sources and in the lower depths of
some thermally stratified lakes and reservoirs. While there is no health-based maximum
contaminant level for these metals, EPA has established secondary maximum contaminant
levels (SMCLs) for iron and manganese of 0.3 mg/L and 0.05 mg/L, respectively. These SMCLs
are based on aesthetic issues (red water, staining of clothing). While aluminum occurs naturally
in groundwater and soil due to the erosion of aluminum-bearing minerals (USEPA, 2006a), it is
more frequently found in drinking waters treated with alum for coagulation. It can also be an
impurity in lime. Aluminum can color water, so EPA has set a SMCL of 0.05 - 0.2 mg/L.14 Iron,
manganese, and aluminum are common water quality parameters that can be measured by a
certified laboratory.
Systems that increase pH for lead and/or copper control may experience black or red water
complaints due to oxidation of iron and manganese in the distribution system. Iron and
manganese removal at the treatment plant, or possibly the use of sequestering agents or
silicates, can be used in these cases (see Chapter 3 for more information).
New research has shown that manganese and iron can react with dissolved lead and form
deposits on lead service lines and other pipes in premise plumbing. In the well-studied case of
Madison, Wl, manganese that accumulated on pipe scales (up to 10 percent by weight of scale
composition) captured dissolved lead and later released it back into the drinking water (Schock,
Triantafyllidou, et al., 2014). Manganese can also interfere with the formation of PbCh and
other passivating films (Schock, Triantafyllidou, et al., 2014).
Aluminum can interfere with orthophosphate effectiveness by forming aluminum phosphate
precipitates, which reduce the amount of orthophosphate available for lead and copper
control. Aluminum phosphate precipitates also have the potential to form scales on the interior
of piping systems that may reduce the effective diameter of the pipes, resulting in loss of
hydraulic capacity and increases in system headless and operational costs (AWWA, 2005).
The 2006 EPA Report, Inorganic Contaminant Accumulation in Potable Water Distribution
Systems notes that, "Based on scale sample analysis from 10 water utilities that practice alum
coagulation, Snoeyink et al. (2003) confirmed that aluminum is frequently a major component
of lead pipe scale" (USEPA, 2006b). These scales, however, are generally not as stable
14 "While EPA encourages utilities to meet a level of 0.05 mg/l for aluminum where possible, the Agency still believes that
varying water quality and treatment situations necessitate a flexible approach to developing the SMCL. What may be
appropriate in one case may not be appropriate in another. Hence, a range was developed for the aluminum SMCL" (USEPA,
2010a).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 19
-------
compared to orthophosphate scales and are prone to sloughing with changes in flow or water
quality, or when lead service lines are physically disturbed during routine maintenance and
repair activities. These dislodged scales can release metals that may become entrapped in the
interior (premise) plumbing and/or the faucet screen, potentially increasing lead and copper
levels in the water (Schock, 2007b).
2.4 Physical and Hydraulic Factors Affecting Release of Lead and Copper
In addition to water quality parameters, physical factors such as pipe disturbances, hydraulics,
water use, and water temperature can affect lead and copper levels at the customer's tap.
Understanding these factors can help primacy agencies and systems interpret lead and copper
data and evaluate the effectiveness of OCCT.
2.4.1 Physical Disturbances
Field sampling has shown that physical disturbances to LSLs related to infrastructure work can
result in lead release. Del Toral et al. (2013) found that most lead sampling results above the
LCR lead action level of 0.015 mg/L occurred at sites with physical disturbances compared to
undisturbed sampling sites.15 Lower water usage at the disturbed sites may have also been a
factor in the higher lead levels found.
Any physical disturbance to the premise plumbing system, from service to tap, can cause lead
particulate release. Physical disturbances resulting in lead particulate release can occur during:
• Meter installation or replacement.
• Auto-meter-reader installation.
• Service line repair or partial replacement.
• External shut-off valve repair or replacement.
• Significant street excavation directly in front of the house.
• Repair or replacement of home plumbing fixtures or piping.
When any part of a home plumbing system is drained for repair work, or when infrastructure
upgrades or repairs are completed (e.g., main breaks), air may get into the lines and scour
deposits from the service lines to the tap. Tap flushing to remove air bubbles can disrupt pipe
scales and release lead, copper and other accumulated material in the scales.
2.4.2 Hydraulic Factors
High water velocity can help reduce lead and/or copper by transporting the corrosion inhibitor
to pipe surfaces at a higher rate; however, in some cases it can increase lead and/or copper
corrosion by increasing the rate at which the oxidants in water come into contact with the
15 Sampling included first draw and lead profile sampling. The percent of samples with lead levels greater than 0.015 mg/L was
36% for sites with known disturbances (13 sites and 327 samples), 37 % for indeterminate sites where the disturbance could
not be verified (2 sites, 81 samples), and 2% for undisturbed sites (16 sites, 372 samples).
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 20
-------
metal surface. High water velocity can cause corrosion in copper pipes, and can also mobilize
loosely adherent scale and cause sporadic lead release (Schock, 1999). Low water velocity in
areas of low water usage can reduce the effectiveness of the corrosion control inhibitor in
forming a passivating scale. Increased water age due to less frequent use can cause water
quality changes such as reductions in pH and loss of free chlorine residual that could exacerbate
corrosion as well as microbial problems.
Other hydraulic factors that can affect lead and copper release into the customer's service line
or a building's plumbing include flow reversals and hydraulic pressure transients. Pressure
transients may occur when valves are closed to perform maintenance (Friedman et al., 2010) or
due to backflowfrom a cross connection. Residential backflow is more common than previously
thought, according to a recent study that identified backflow events in 5 percent of homes with
backflow sensing meters (Schneider et al., 2010). Hydraulic pressure transients may occur when
there are sudden changes in water velocity due to valves slamming shut, power outages, or
pump start/stop cycles (Friedman et al., 2010).
2.4.3 Water Use
The effectiveness of corrosion control inhibitors depends on delivery of the inhibitors to the
pipe wall to form the passivating scale. Reductions in water use may adversely affect this
process. Also, as stated above, increased water age from less frequent use can cause water
quality changes, such as reductions in pH and loss of free chlorine residual, that can exacerbate
corrosion as well as microbial problems.
2.4.4 Water Temperature
Water temperature effects are complex and depend on the water chemistry and type of
plumbing material. More lead is often mobilized during warmer weather seasons, although
temperature effects can vary depending on water quality conditions and plumbing
configuration. For example, as reported by Schock and Lytle (2011), orthophosphate reacts
more quickly at higher temperatures, so reduction in lead levels may take longer in colder
months than in warmer months. Higher temperature can also exacerbate copper corrosion,
although elevated temperature has been found in some instances to facilitate a better
passivating copper pipe scale (Schock and Lytle, 2011).
Seasonal changes in water temperature can result in significant changes in water quality and
can impact lead and copper release. Because of the many reactions happening in the
distribution system, it is difficult to generalize temperature's impacts. Water systems should
collect water quality and lead and copper data throughout the year to determine their own
trends.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 21
-------
Chapter 3: Corrosion Control Treatment for Lead and Copper
This chapter provides technical information on available corrosion control treatment (CCT)
methods for lead and copper (Section 3.1), technical recommendations for identifying
treatment alternatives for individual systems (Section 3.2), and technical recommendations for
identifying target water quality and dosages for treatment alternatives (Section 3.3). The
information in this chapter can be used to support systems and primacy agencies in meeting
CCT requirements of the Lead and Copper Rule (LCR). Note that this chapter provides
background information and technical recommendations - see Chapters 4 and 5 for a review of
the required CCT steps under the LCR and when CCT requirements apply.
3.1 Available Corrosion Control Treatment Methods
Alkalinity and pH adjustment has been used by many systems for corrosion control. The
discussion of this method is expanded in this section to include dissolved inorganic carbon (DIC)
adjustment because all three parameters are a better indicator of corrosion control
effectiveness than pH and alkalinity alone.
Phosphate-based corrosion inhibitors have been widely used to control lead and copper
release. Their applications for corrosion control have been updated in this chapter to include
more recent information on chemical formulations, optimal pH ranges, and limitations to their
use.
Information on the use and effectiveness of silicate-based corrosion inhibitors continues to be
limited and more research is needed. They may be effective in reducing lead and copper release
in some cases, however, so they are included as a treatment technique in this chapter.
Calcium hardness adjustment is not discussed in this chapter because newer research has
shown that calcium carbonate films only rarely form on lead and copper pipe and are not
considered an effective form of corrosion control (Schock and Lytle, 2011; Hill and Cantor,
2011). Calcium hardness is important, however, in evaluating the amount of pH adjustment
that can be made without causing calcium carbonate precipitation and resultant scaling
problems in the distribution system.
New research has found that lead service lines (LSLs) with PbCh scales can have very low lead
release (levels as low as or lower than those found when orthophosphate treatment is used
(Schock, Cantor, et al., 2014)). This new information has significant implications for
management of treatment and distribution systems to minimize the release of lead. Questions
remain, however, on how systems and primacy agencies can ensure that disinfectant residuals
required for the formation and maintenance of PbCh scales are maintained in LSLs throughout
the distribution system. This may be a particular challenge with homes that go unoccupied for
an extended period of time. Therefore, formation of PbCh scale is not included in this section as
a corrosion control technique. If systems have PbCh scales, they should be very careful about
making disinfection changes (see Chapter 6 for more information).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 22
-------
The remainder of this sub-subsection describes the specific chemical/physical methods that can
be used for pH/alkalinity/DIC adjustment, phosphate-based corrosion inhibitors, and silicate-
based corrosion inhibitors.
3.1.1 pH/Alkalinity/DIC Adjustment
As noted in Chapter 2, there are ranges of pH, alkalinity, and DIG that result in formation of
insoluble compounds in the scale and in this way prevent the release of lead and copper (see
Section 3.3.1 for recommended target pH/alkalinity/DIC ranges). Adjustment of
pH/alkalinity/DIC can be accomplished by chemical or non-chemical means. Typical chemicals
used for pH/alkalinity/DIC adjustment for corrosion control are listed in Exhibit 3.1. Additional
information and guidance on pH adjustment methods are provided in USEPA (1992a) and Hill
and Cantor (2011).
In addition to chemical methods, pH/alkalinity/DIC adjustment can be accomplished using
limestone contactors or aeration. Limestone contactors, which are enclosed filters containing
crushed high-purity limestone, have been used at small systems because they are relatively
easy to operate. As the water passes through the limestone, the limestone dissolves, raising the
pH, alkalinity, DIG, and calcium of the water. An empty bed contact time of 20 to 40 minutes is
typically used to optimize pH and alkalinity adjustment. If a high pH is needed, other media
types (e.g., dolomite, dolomitic materials) may be available regionally. When using limestone
contactors, the influent should have pH < 7.2, calcium < 60 mg/L, alkalinity < 100 mg/L, and DIG
< 10 mg/L. For influent pH >7.2, carbon dioxide can be added prior to the contactors. Limestone
contactors can also be used for iron removal but require backwash capabilities to remove iron
that accumulates on the limestone. Recommendations on the design and application of
limestone contactors can be found on the following Environmental Protection Agency (EPA)-
funded website
http://www.unh.edu/wttac/WTTAC Water Tech Guide Vol2/limestone intro.html.
Aeration is a non-chemical method for adjusting pH where air is introduced into the water.
Aeration is the only method that reduces excess DIG by removing carbon dioxide, which results
in an increase in pH. Aeration systems include Venturi injector systems, tray systems, packed
tower systems, and diffuse bubble systems. They can be designed to remove other constituents
such as iron, manganese, radon, volatile organic compounds (VOCs) and hydrogen sulfide (HhS).
Aeration is most effective when there is an adequate carbon dioxide concentration in the water
(4 -10 mg/L C02), and the pH is < 7.2 (Spencer and Brown, 1997; Lytle et al., 1998; Spencer,
1998; AWWA, 1999; Schock et al., 2002; AWWA, 2005).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 23
-------
Exhibit 3.1: Typical Chemical Processes for pH/Alkalinity Adjustment
Chemical
Baking Soda,
NaHCOs,
(sodium
bicarbonate)
Carbon
Dioxide, CO2
Caustic Soda,
NaOH
(sodium
hydroxide)
OrKOH
(potassium
hydroxide)1
Hyd rated
Lime, Ca(OH)2
(calcium
hydroxide)2
Soda Ash,
Na2C03
(sodium
carbonate)
Or
Potash, KCOs
(potassium
carbonate)
Sodium
Silicates
Na2SiOs
Use
Increases
alkalinity with
moderate
increase in pH.
Lowers pH.
Converts
hydroxide to
bicarbonate
and carbonate
species.
Raises pH.
Converts
excess carbon
dioxide to
carbonate
alkalinity
species.
Raises pH.
Increases
alkalinity and
calcium content
(i.e., hardness).
Increases
alkalinity with
moderate
increase in pH.
Moderate
increases in
alkalinity and
PH
Composition
95% purity.
Dry storage with
solution feed.
Pressurized gas
storage. Fed either
through eduction or
directly.
93% purity liquid bulk,
but generally shipped
and stored, at < 50%
purity to prevent
freezing. KOH has a
higher freezing point
and may be stored at
higher concentrations.
95 to 98% purity as
Ca(OH)2.
74% active ingredient
as CaO.
Dry storage with slurry
feed.
95% purity.
Dry storage with
solution feed.
Available in liquid form
mainly in 1:3.2 or 1:2
ratios of Na2O:SiO2
Alkalinity
Change
0.60 mg/L
as CaCOs
alkalinity
per mg/L
as NaHCOs
None
1 .55 mg/L
as CaCOs
alkalinity
per mg/L
as NaOH
1.21 mg/L
as CaCOs
alkalinity
per mg/L
as Ca(OH)2
0.90 mg/L
as CaCOs
alkalinity
per mg/L
as
Na2HCO3
Depends
on
formulation
DIC
Change
0.14
mg/L as
C per
mg/L as
NaHCOs
0.27
mg/L as
C per
mg/L as
C02
None
None
0.11
mg/L as
C per
mg/L as
Na2CO3
None
Notes
Good alkalinity
adjustment chemical but
expensive.
Can be used to enhance
NaOH or lime feed
systems.
pH control is difficult
when applied to poorly
buffered water.
Is a hazardous
chemical, requires safe
handling and
containment areas
pH control is difficult
when applied to poorly
buffered water. Slurry
feed can cause excess
turbidity. O&M is
intensive.
More pH increase
caused compared with
NaHCOs, but less costly.
Has increased buffer
capacity over
hydroxides.
More expensive than
other options but easier
to handle than lime and
other solid feed options.
Has additional benefits
in sequestering or
passivating metals.
Source: Adapted from USEPA, 1992a. Additional detail on characteristics from AwwaRF, 1990, pages 133-143; USEPA, 2003;
AWWA, 1999. Schock, 1996.
Notes:
Caustic potash (KOH), or potassium hydroxide, is an alternative that does not add sodium to water.
2Lime is available as hydrated or slaked lime (Ca(OH)2) and quicklime (CaO).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
24
-------
3.1.2 Phosphate-Based Inhibitors16
As noted in Chapter 2, phosphate-based corrosion inhibitors are chemicals that have
orthophosphate in their formulation.17 Orthophosphate reacts with divalent lead and copper
(i.e., Pb++ and Cu++) to form compounds that have a strong tendency to stay in solid form and
not dissolve into water. The extent to which orthophosphate can control lead and copper
release depends on the orthophosphate concentration, pH, DIG, and the characteristics of the
existing corrosion scale (e.g., whether it contains other metals such as iron or aluminum).
Orthophosphate is available as phosphoric acid, in salt form (potassium or sodium), and as zinc
orthophosphate. Phosphoric acid (HsPCu) is a common form that is available in concentrations
between 36 and 85 percent. Because it is an acid, it requires special handling and feed facilities.
Zinc orthophosphate inhibitors typically have zinc: phosphate weight ratios between 1:1 and
1:10. Recent research found that zinc orthophosphate did not provide additional lead and
copper control compared to orthophosphate (Schneider et al., 2010). The zinc did, however,
provide better corrosion protection for cement at low alkalinity/hardness/pH conditions.
Blended phosphates are a mix of orthophosphate and polyphosphate, with the orthophosphate
fraction ranging from 0.05 to 0.7. It is possible that blends can provide both sequestration of
metals and reduce metals release (Hill and Cantor, 2011). It is important to note that blended
phosphates may not function as corrosion inhibitors strictly on the basis of concentration and
relative amount of orthophosphate. See Section 3.3 for more information and recommended
special considerations for using blended phosphates.
3.1.3 Silicate Inhibitors
Silicate inhibitors are mixtures of soda ash and silicon dioxide. These treatment chemicals are
available in liquid or solid form (AwwaRF, 1990; Reiber et al., 1997; USEPA, 2003). They have
been shown in a few cases to reduce lead and copper levels in first draw, first liter tap samples
(LaRosa-Thompson et al., 1997; Schock et al., 2005). They have not been used in many full-scale
plants because they have traditionally been more expensive than phosphate-based inhibitors
and can require high doses.
The mechanisms by which silicate inhibitors control lead and copper release have been debated
in the literature. Silicates may form an adherent film on the surface of the pipe that acts as a
diffusion barrier. Silicates will also increase the pH of the water, which may reduce lead and
copper release. The effectiveness of the formation of a diffusion barrier depends on pre-
existing corrosion products on the scale to provide a site for the binding of the silicate layer
(LaRosa-Thompson et al., 1997).
16 As noted in Chapter 2, polyphosphates, which are used mainly as sequestrants for iron and manganese, have not been found
to be effective on their own to control lead and copper release.
17 Orthophosphate concentration can be measured as P (phosphorus) or PCU (phosphate). It is very important to be clear about
which measurement is being used. An orthophosphate concentration of 3 mg/L as PCU is roughly equivalent to 1 mg/L as P.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 25
-------
Silicates are defined by a weight ratio of Si02:Na20. A ratio of 3.22 is typical, although sodium
silicate solutions with ratios as low as 1.6 are commercially available (Schock and Lytle, 2011;
Schock, Lytle, etal., 2005).
3.2 Technical Recommendations for Selecting Treatment Alternatives
The process that systems must follow before the primacy agency designates OCCT is
established in the LCR and differs in part based on system size. All systems, however, must
recommend to the primacy agency a treatment option for designation as OCCT. This section
contains technical recommendations to support primacy agencies, water systems, and if
applicable, outside technical consultants in evaluating treatment alternatives to control lead
and copper release. These technical recommendations may be particularly useful for systems
serving 50,000 or fewer people when developing their OCCT recommendation, or for larger
systems identifying corrosion control alternatives for further study. See Chapters 4 and 5 for a
review of CCT requirements under the LCR.
This section includes flowcharts to support the corrosion control selection process. These
flowcharts are based on the 1997 EPA document, Guidance for Selecting Lead and Copper
Control Strategies (1997) and the revised guidance with the same name, published in 2003. This
section reflects new research related to the control of copper corrosion and blended
phosphates, as well as new research related to corrosion control in systems with raw water iron
and manganese.
The following technical recommendations are discussed in this section:
• STEP 1. Review Water Quality Data and Other Information.
• STEP 2. Evaluate Potential for Scaling.
• STEP 3. Select One or More Treatment Option(s).
• STEP 4. Identify Possible Limitations for Treatment Options.
• STEP 5. Evaluate Feasibility and Cost.
Section 3.3 follows with technical recommendations on setting dose and target water quality
parameters. Special considerations for systems with LSLs, small systems, and systems with
multiple sources are provided below.
• Considerations for systems with LSLs: Systems with LSLs may want to evaluate the
feasibility and cost effectiveness of fully removing all LSLs (utility-side and customer-
side). Full LSL removal has several operational benefits - for example, systems using
orthophosphate may be able to reduce their dose when LSLs have been fully removed.
Also, removing the source of lead reduces the vulnerability of the system to unexpected
changes in lead release due to future water quality changes.
• Considerations for very small community water systems (CWSs) and non-transient,
non-community water systems (NTNCWSs): Systems that directly control 100 percent
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 26
-------
of their plumbing fixtures and components may want to consider physically replacing all
lead-containing or copper plumbing materials. Systems should verify that the new
components are certified "lead-free" according to current standards (See Section 2.1 for
the definition of "lead-free"). Point-of-use (POD) treatment units, if they meet the
SDWA requirements, may be an option in limited circumstances.18 Note systems that
select plumbing replacement or POD devices must continue the CCT steps described in
Section 4.1 unless they are deemed optimized.19 In cases where very small CWSs and
NTNCWSs are identifying CCT, they should consider technologies that are easy to
operate (e.g., limestone contactors, aeration) and select chemicals that are easy to store
and work with, such as baking soda.
• Considerations for systems with more than one source: Many systems will have unique
source and treatment scenarios that make system-wide corrosion control
recommendations difficult. It may be prudent for systems with multiple wells or
multiple sources, or systems that purchase waters of differing quality that enter the
distribution system at various locations, to determine the most appropriate treatment
separately for each source then undertake a system-wide evaluation of the most
effective way to implement and operate corrosion control.
It is also important to recognize the potential limitations of treatment in chronic low water
usage homes and homes that have been unoccupied for extended periods of time. The
treatment may not be effective at lowering lead and/or copper levels at these sites which can
pose an ongoing risk to these residents. Systems should consider other potential actions they or
residents can take to address the potential risk at these sites.
3.2.1 Technical Recommendations for Reviewing Water Quality Data and Other Information
(STEP 1)
Lead and Copper Data
The forms in Appendix D can be used to organize lead and copper tap sampling data for system
and primacy agency review. In addition to their own data, systems and primacy agencies should
review any additional lead and copper data collected by others (e.g., universities).
Systems and primacy agencies should consider evaluating the dates and locations of individual
sample results above the lead or copper action level(s) to determine if there are any spatial or
temporal patterns. These results could be compared to water quality data collected at nearby
distribution system locations at similar times to determine if they coincided with unusual water
18 For additional information refer to : 1) the preamble to the 2007 LCR Short-Term Revisions (USEPA, 2007a); and 2) Point-of-
Use or Point-of-Entry Treatment Options for Small Drinking Water Systems, EPA 815-R-06-10 (USEPA, 2006a).
http://www.epa.gov/sites/production/files/2015-09/documents/guide smallsvstems pou-poe iune6-2006.pdf.
19 One way for systems serving 50,000 or fewer people to be deemed to have optimized corrosion control is they conducted
lead and copper tap monitoring for two consecutive 6-month monitoring periods without a lead or copper action level
exceedance, regardless of whether they have installed CCT (§141.81(b)(l)).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 27
-------
quality (e.g., changes in pH, corrosion inhibitor concentration or microbiological activity).
Systems should determine if sample results above the action level(s) coincided with a change in
treatment or source. Lastly, systems should compare these sample results to previous rounds of
lead and copper tap monitoring to see if there is a reoccurring pattern of lead and/or copper
occurrence above the action level(s) at specific locations.
Systems may want to talk to residents where the sample results were above the action level(s)
to discuss the resident's sampling procedure, ask for information on water use patterns and
stagnation time prior to sampling, and ask about any physical disturbances that may have
occurred prior to sampling (e.g., building renovations and other construction work on the
property). A good way to collect information ahead of time is on a comprehensive chain of
custody (COC) form. The COC form, given to the resident to send in with the sample, can be
designed to collect information on sampling procedure, stagnation time, and flushing time.
Talking with residents about their sample results provides an opportunity for systems to discuss
one-on-one with consumers the public health implications of lead and copper and ways in
which residents can reduce their exposure.20
For locations with sample results above the action level(s), systems and primacy agencies may
want to consider additional sampling21 to determine the source of the lead so that the system
and property owner might consider site-specific remediation in addition to actions required by
the regulations. See Appendix C for technical recommendations on investigative sampling
methods to determine the source of lead and copper.
Other Water Quality Data and System Information
Systems and primacy agencies should collect and review water quality data and other system
information pertinent to corrosion of lead and copper containing materials. Systems can use
the forms in Appendix D to organize available water quality data and information and submit it
to their primacy agency.
Analysis of a broad range of water quality constituents can be a very cost effective approach to
identification of appropriate treatment technologies. For example:
• Having very accurate pH and alkalinity/DIC data is important for assessing the feasibility
of such simple treatments as aeration or limestone contactors.
20 Note that systems must conduct public education as required by the LCR when they exceed the lead action level (§141.85).
Public education guidance for CWSs is provided in the document, "Implementing the Lead Public Education Provisions of the
Lead and Copper Rule: A Guide for Community Water Systems" (USEPA, 2008a) and in a similarly titled guidance for NTNCWSs
(USEPA, 2008b).
21 All lead and copper tap sample results from the system's sampling pool collected within the monitoring period must be
included in the 90th percentile calculation along with any samples where the system is able to determine that the site selection
criteria in §141.86(a)(3)-(8) for the sampling pool are met. Other lead and copper tap data such as from customer requested
sampling, investigative sampling, and special studies must be submitted to the primacy agency (USEPA, 2004e; §141.90(g)).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 28
-------
• Having calcium, magnesium, sulfate, iron, manganese, and other water quality data may
help define constraints on pH adjustment, phosphate dosing, use of packed tower
aerators, membranes or other processes, because of scale buildup issues.
• Knowing whether arsenic or radon is present in the source water will dictate CCTs that
are compatible with the removal processes for those contaminants. For example,
aeration can be used for radon removal as well as for pH adjustment for corrosion
control, potentially reducing or eliminating the need for chemical treatment.
• If iron and/or manganese are present, they can interfere with the effectiveness of CCT.
A combination of a removal process or filtration following oxidation (e.g.,
aeration/disinfection) might be cost-effective and would reduce or eliminate the need
for sequestration. Similarly, iron removal processes can often remove arsenic if present.
Primacy agencies and systems can use the information in Chapter 2 to review the data and
identify water quality and physical factors that may be contributing to lead and/or copper
release. When lead and copper monitoring data appear to be at odds with corrosion control
theory, additional unknown factors may be involved. Those critical factors can only be
determined by more specific evaluation and studies, such as direct examination of the pipe
scales, additional data collection and evaluation or examining the physical layouts of individual
sampling sites.
3.2.2 Technical Recommendations for Evaluating the Potential for Scaling (STEP 2)
The presence of calcium in the water may limit the system's ability to raise the pH due to
scaling problems in the distribution system. Scaling can clog pipes, reduce carrying capacity,
and cause the water to be cloudy. Before selecting possible treatments, EPA recommends that
systems and primacy agencies identify the saturation pH for calcium carbonate for the system.
Maintaining the pH below the saturation pH should help to minimize, although not eliminate,
the potential for precipitating calcium carbonate. It is important to note that other constituents
in the water such as trace metals, natural organic matter (NOM), ligands, and phosphates can
affect calcium carbonate precipitation rates and result in a higher or lower saturation pH.
The steps for determining the saturation pH are as follows:
• Determine the DIG of the water. If DIG data are not available but alkalinity and pH are
known, use the tables in Appendix B to determine the target DIG (in mg/L as carbon).
• Determine the finished water calcium concentration in mg/L. If this is not known but the
system has total hardness data, approximate the calcium concentration by dividing the
finished water hardness (as mg/L CaCOs) by 2.5.
• On Exhibit 3.2, find the intersection of DIG on the x-axis (in "mg C/L") and calcium on the
y-axis (in "mg Ca/L"). Find the pH curve closest to the intersection. This is the saturation
pH for the system.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 29
-------
100 125 150
0 5 10 15 20 25 30 35 40 45 50
mg C/L DIG
Exhibit 3.2: Theoretical Saturation pH for Calcium Carbonate Precipitation (USEPA, 2003)
Notes:
Solid lines are pH in whole numbers. Dashed lines are pH increments of 0.2
Calcium values are in mg Ca/L. To approximate calcium concentration (in mg Ca/L) from a measured hardness (as mg/L CaCOS),
divide the hardness value by 2.5.
3.2.3 Technical Recommendations for Selecting One or More Treatment Option(s) (STEP 3)
Systems and primacy agencies can use Flowcharts la through 3b in this section to select
candidates for CCT. Exhibit 3.3 is a starting point for systems and primacy agencies to select the
most appropriate flowchart for their situation based on whether the system has iron and/or
manganese in finished water, is treating for lead and/or copper, and on pH in the distribution
system.
These flowcharts were originally developed as a tool for small systems in EPA's 2003 revised
guidance manual on selecting lead and copper corrosion strategies (USEPA, 2003), but they can
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
30
-------
be useful for all system types. The flowcharts have been updated to reflect new research
conducted since 2003.
These flowcharts are a screening tool and are not meant to substitute for pilot studies and
other site-specific investigations. They are meant to indicate likely possibilities and do not
include information on optimizing any of the treatments. In particular, systems with LSLs should
work with their primacy agencies to select treatment that most effectively reduces lead release
from the service line and should also consider full LSI replacement as recommended earlier in
this chapter. Also as stated elsewhere in this document, the presence of other chemicals in the
finished water such as aluminum, iron, manganese, and calcium may interfere with CCT and
point to a need for additional studies and/or alternative control options.
Additional information on setting water quality parameters and dose for the treatment options
is provided in Section 3.3.
Exhibit 3.3: Identifying the Appropriate Flowchart for Preliminary CCT Selection
Is iron or manganese
present in finished
water?
No
Yes1
What is the
contaminant to be
addressed?
Lead only, or
Both Lead and
Copper
Copper only
Lead and/or Copper
What is the finished
water pH?
<7.2
7.2-7.8
>7.8-9.5
>9.5
<7.2
7.2-7.8
>7.8
<7.2
>7.2
Use This Flowchart
la
Ib
Ic
Id
2a
2b
2c
3a
3b
1. Flowcharts 3a and 3b present several treatment options for lead and copper that also reduce iron and
manganese. Systems can also consider removing iron and manganese first, then using flowcharts la through 2c to
control for lead and/or copper.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
31
-------
Flowchart la: Selecting Treatment for Lead only or Lead and Copper with pH < 7.2
f Start Here J
<5 mg/L as C-
Raise the pH in 0.5 unit
increments and DIG to
5-10 nng/L as C using
one of the following:
• Soda Ash
• Potash
* Limestone contactor
> 15 mg/L as C-
5-15 mg/L as C
i
1. Raise the pH in 0.5
unit increments using
one of the following:
• Soda Ash
• Potash
• Caustic Soda
• Aeration
• Silicates
OR
2. Add orthophosphate
and raise the pH to 7.2
-7.8.
1. Raise the pH in 0.25
unit increments using
one of the following:
• Soda Ash
• Potash
• Caustic Soda
• Aeration
OR
2. Add orthophosphate
and raise the pH to 7.2
-7.8.
KEY:
AL= Action Level
Caustic so da = sodium hydroxide (NaOH)
DK = Dissolved Inorganic Carbon
mg/L asC= Milligrams per liter as carbon
Potash = potassium carbonate (K^CO;)
Soda ash =sodium carbonate (Nas.COj)
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
32
-------
Flowchart Ib: Selecting Treatment for Lead only or Lead and Copper with pH from 7.2 to 7.8
f Start here J
<5 mg/Las C-
Raisethe pH in 0.5
unit increments and
DIG to 5-10 mg/L as C
using one of the
following:
• Soda Ash
• Potash
• Limestone
contactor1
>25 mg/Las C-
5-25 mg/L as C
1. Raise the pH in 0.3
unit increments
using one of the
following:
• Soda Ash
• Potash
• Caustic Soda
• Silicates
• Aeration
OR
2. Add
Qrt ho phosphate
1. Add
Ortho phosphate
KEY:
AL= Action Level
Caustic soda= sodium hydroxide (NaOH)
DC = DissoSved Inorganic Carbon
mg/L asC = mBligramsper liter as carbon
Potash = potassium carbonate (KZCO=.)
Soda ash = sodium carbonatefNazCOs)
Footnotes:
1. Carbon dioxide feed before the limestone
contactor may be necessary.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
33
-------
Flowchart Ic: Selecting Treatment for Lead only or Lead and Copper with pH > 7.8 to 9.5
( Start Here )
< 5 mg/L as C
>5 mg/L as C
Raise the DIG to 5-10
mg/L as C using one of
the folio wing:
• Soda Ash
• Potash
* Baking Soda
1
Raise the pH in 0.3
unit increments
toward 9-9.5 using:
• Caustic Soda1
OR
OR
KEY:
AL= Action Level
Baking soda = sodium bicarbonate (NaHCOj)
Caustic soda= sodium hydroxide (NaOH)
D C = D sso ,ved ncrgan c Carbon
mg/L as C = milligrams per liter as carbon
Potash = potass "urn carbonate (K:CO 5)
Soda ash = sodium carbonate (NaiCO=)
Footnotes
1. Svstemswith copper piumb'ng may
experience copper pitting problems when
operating atpH9-9.5 and DC of 5 -15.
Orthophosphate may be a better option for
these systems
Z.Optimal pH range for orthophosphate is
7.2 -7.8 but phosphate may be effective at
higher pH depending on dose.
0 rtho pho sp hate effect v eness is low est in
the pH range of S-8.5. Systems should also
avoid this range because of inadequate
buffering in the distribution system.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
34
-------
Flowchart Id: Selecting Treatment for Lead only or Lead and Copper with pH > 9.5
( Start Here
<5 mg/La5C
1
Raise the DIG to 5-10
mg/L as C using:
• Baking Soda
>5 mg/L as C
Additional lowering of
lead may not be
possible with
treatment. Investigate
cause of lead release.
KEY:
AL= Action Level
Baking soda = sodium bicarbonate (NaHCO;)
DC = Dissolved Inorganic Carbon
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
35
-------
Flowchart 2a: Selecting Treatment for Copper Only with pH < 7.2
f Start Here )
— < 5 mg/L as C-
Raisethe pH in 0.5
unit increments and
DIG to 5-10 mg/L as C
using one of the
following:
• Soda Ash
• Potash
• Limestone
contactor
• > 35 mg/L as C-
5-35 mg/L as C
Raise the pH in 0.5
unit increments using
one of the following:
« Potash
• Caustic Soda
• Aeration1
• Silicates
1. Remove DIG using
one of the following
methods:
• Conventional
Lime or Lime
Softening
• Membranes or
Anion Exchange,
followed by pH
adjustment2
OR
2. Add Orthophosphate
and raise the pH to
7.2 - 7.8.
KEY:
AL= Action Level
Caustic soda= sodium hydroxide (NaOH)
DC= Dissolved Inorganic Carbon
mg/L asC = mSligramsper liter as carbon
Potash = potassium carbonate (K;CO3)
Soda ash = sodium carbonate (NaiCOa)
Footnotes
1. May be most appropriate at hgher end of DIG rsn.|e
2. To achieve optimal levels, consider treating less than 100 percent of the
water (i.e., spit stream).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
36
-------
Flowchart 2b: Selecting Treatment for Copper Only with pH from 7.2 to 7.8
( Start Here J
• < 5 mg/L as O
Raise the pH in 0.5
unit increments and
DIG to 5-10 mg/L as C
using one of the
following:
• Soda Ash
* Potash
• Limestone
contactor1
> 25 mg/L as C-
5-25 mg/L as C
1. Raise the pH in 0.3
unit increments
using one of the
following:
• Soda Ash
« Potash
• Caustic Soda
• Silicates
• Aeration2
1. Add
Qrthophosphate
KEY:
AL = Action Level
Caustic soda = sodium hydroxide(NaOH)
DC = Dissotved Inorganic Carbon
mg/L asC = milligrams per liter ascarbon
Potash = potassium carbonate(K;CO=)
Soda ash = sodium carbonate (NazCCVj
Footnotes
1. Carbon dioxide feed before the imestone contactor may
be necessary.
2. May be most appropriate at higher end of DC range
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
37
-------
Flowchart 2c: Selecting Treatment for Copper Only with pH > 7.8
f Start Here ]
<25 mg/LasC
> 25 mg/L as C-
Raisethe pH in 0.3
unit increments and
DIG to 5-10 mg/L as C
using one of the
following1:
• Soda Ash
• Potash
1. Add
Ortho phosphate
KEY:
AL= Action Level
DtC = Dissolved Inorganic Carbon
mg/L as C= milligrams per liter as carbon
Potash = potassium carbonate (KiCQ =.)
Soda ash = sodium carbonate (
Footnotes
1. Carbon dioxide feed before the limestone
contactor mav be necessarv.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
38
-------
Flowchart 3a: Selecting Treatment for Lead and/or Copper with Iron and Manganese in
Finished Water and pH < 7.2
[ Start Here )
— < 5 mg/L as C-
Raise the pH in 0.5
unit increments and
DIG to 5-10 mg/L as C
using one of the
following:
• Soda Ash
• Baking Soda and
Silicates L
,.-'-"' What is \
\the DIG?/
5- 12m
,
g/L as C > 12-25 r
,
1. Raise the pH using
one of the
following:
• Soda Ash
• Caustic Soda
• Silicates1
OR
2. Add Silicates
> 25 mg/L as C—
ng/Las C
,
Raise the pH to 7.2-
7.5 using:
• Caustic Soda
AND
• Add Blended
Phosphate2
r
Adjust the pH to 7.0-
7.2 using:
• Caustic Soda
AND
• Add Blended
Phosphate2
KEY:
AL= Action Level
Caustic soda = sodium hvdroxide (NaQH)
DIC = Dissolved Inorganic Carbon
mg/I asC = nrtiligramspef liter as carbon
Soda ash = sodium carbonate (Na^COj)
Footnotes:
1.Silicates are most effective when combined iron and manganese
concentrations are lessthan l.Omg/L.
2.The effectiveness of blended phosphate varies based on the
formulation. Additional evaluation and/or monitoring is
recom mended. See Section 3.3.2 for additional discussion.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
39
-------
Flowchart 3b: Selecting Treatment for Lead and/or Copper with Iron and Manganese in
Finished Water and pH > 7.2
c
Start Here
J
• < 5 mg/L as C
> 5 mg/L as C-
RaisetheDICto5-10
mg/L as C using one of
the folio wing:
* Silicates1
• Baking Soda and
Blended
Phosphate2
1. Add Blended
phosphate z
OR
2. Remove source
water iron and/or
manganese and
add
orthophosphate
with pH adjusted
to 7.2-7.8.
KEY:
AL = Action Level
Bak rig soda = sodium bicarbonate (NaHC05)
DK. = Dissoived Inorganic Carbon
mg/L 3GC = milligrams per liter as carbon
Footnotes:
1.Silicates are most effective when combined iron and manganese
concentrations are lessthan 1.0 mg/L.
2.The effectiveness of blended phosphate varies based on the
formulation. Additional evaluation and/or monitoring is
recommended. See Section 3.3.2 for additional discussion. Blended
phosphates are less effective for controlling copper at DIG greater
than 25 mg/L asC.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
40
-------
3.2.4 Technical Recommendations for Identifying Possible Limitations for Treatment Options
(STEP 4)
Once the treatment option(s) are selected from the flowcharts, review the information in this
section to identify secondary impacts and possible constraints. Many of these constraints can
be overcome with additional treatment modifications at the water treatment plant or
wastewater treatment plant (WWTP). Observations and actions to address secondary impacts
can be documented using Form E-2 in Appendix E.
Possible Limitations of pH/alkalinity/DIC Adjustment
Although many systems have successfully adjusted pH, alkalinity, and DIG to control lead and
copper release, this corrosion control method has secondary impacts that may limit its use.
Because silicate addition raises the pH of the water, secondary impacts for this treatment
option are similar to the secondary impacts of raising pH for controlling lead and copper
release.
Three factors that could limit the use of pH/alkalinity/DIC adjustment and silicates are (1)
optimal pH for other processes, particularly disinfection, (2) calcium carbonate precipitation,
and (3) oxidation of iron and manganese. Observations and actions to address secondary
impacts can be documented using Form E-2 in Appendix E.
(1) Optimal pH for other processes
Different treatment processes within the plant such as coagulation and disinfection have
different target pH ranges. Determining the proper location to add a pH and/or alkalinity
adjustment chemical should be considered in light of other process objectives.
Adjusting pH for corrosion control can affect disinfection performance and compliance with
Surface Water Treatment Rules and possibly the Ground Water Rule (for those ground water
systems that are required to provide 4-log virus inactivation). For systems that use chlorine for
primary disinfection, increasing the pH prior to the chlorine contact chamber may reduce
disinfection performance and require an increase in chlorine dose or contact time to meet the
required CT.22 For systems that consider contact time in the piping prior to the first customer as
part of their CT calculation, a higher chlorine dose may be needed to meet CT. To minimize
disinfection impacts, systems should adjust pH for corrosion control after CT has been achieved
if possible. A system that plans to make a significant change to its disinfection practice to
comply with the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR), such as a
change in disinfectant type or process, must develop disinfection profiles and calculate
disinfection benchmarks for Giardia lamblia and viruses (§§141.708-709).
22 CT is chlorine concentration multiplied by contact time. Required CT for chlorine is very dependent on pH, with greater CT
required at higher pH levels.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 41
-------
Changing the pH and/or alkalinity may also impact the ability of a system to maintain a
disinfectant residual in the distribution system. In most cases however, increasing the pH for
corrosion control can help maintain the disinfectant residual because the disinfectant will react
at a slower rate with metals being released at the pipe surface.
Changes in pH can also affect formation of disinfection byproducts (DBFs). Total
trihalomethanes (TTHM) formation tends to increase at higher pH levels, while formation of
haloacetic acids (HAAS) tends to decrease. See the EPA Simultaneous Compliance Guidance
Manual for the Stage 2 and LT2 Rules (USEPA, 2007b) for more information on how pH changes
can impact DBF formation.
(2) Calcium Carbonate Precipitation
If the finished water has high hardness (specifically the calcium portion of hardness), raising the
pH and DIC may cause calcium carbonate to precipitate in the distribution system, clogging hot
water heaters and producing cloudy water. Calcium carbonate precipitation is site-specific and
depends on many factors; therefore, a system evaluation should be conducted as described in
Step 3 above.
If calcium carbonate precipitation is determined to be a potential problem, systems can take
one of the following approaches:
• Choose a different CCT method such as using phosphate-based corrosion inhibitor,
• Remove DIC with ion exchange or membrane filtration, or
• Add softening to remove calcium.
(3) Oxidation of Iron and Manganese
Iron and manganese in oxidized form can agglomerate into larger particles causing aesthetic
problems in water distribution systems, resulting in black and/or red water complaints.
Dissolved oxygen and chemical oxidants such as chlorine may oxidize iron and manganese, and
increasing the pH can increase the rate of oxidation. The two standard approaches for these
situations are removing iron and manganese at the plant, or sequestering it. Wherever possible,
removal of source water iron and manganese is the preferred approach. A common removal
strategy is aeration or chlorination followed by filtration. Aeration will also raise the pH so this
strategy may meet the system's goals of both iron and manganese removal and pH adjustment
for reducing lead and copper release.
Sequestering agents such as polyphosphates and sodium hexametaphosphate may reduce
black and/or red water complaints from iron and manganese oxidation, but may also cause
increases in lead and copper levels measured at the tap (Schock, 1999; Cantor et al., 2000;
Edwards and McNeil, 2002). Vendors often recommend blended phosphates as a lead and
copper control strategy for systems with elevated iron and manganese. Blended phosphates
include both polyphosphate and orthophosphate in different percentages. Blended phosphates
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 42
-------
should be used with caution; see Section 3.3 for more information. Silicates can also be used to
sequester iron and manganese depending on their concentration in the raw water (Schock et
al., 1996; Kvech and Edwards, 2001).
Possible Limitations of Phosphate-Based Corrosion Inhibitors
Although phosphate-based corrosion inhibitors are used widely by water systems, there are
limitations to their application. Two factors that could limit the use of phosphate-based
corrosion inhibitors are (1) reactions with aluminum, and (2) impacts on wastewater treatment
plants. Observations and actions to address secondary impacts can be documented using Form
E-2 in Appendix E.
(1) Reactions with Aluminum
Aluminum can occur in the distribution system as an impurity introduced with lime or when a
system uses alum for coagulation. As noted in Section 2.3, aluminum can interfere with
orthophosphate effectiveness by forming aluminum phosphate (AIPCU) precipitates, which
reduces the amount of orthophosphate available for lead and copper control. Aluminum
phosphate precipitates can result in smaller pipe diameters, increased head-loss, and increased
operational cost (AWWA, 2005). Although aluminum may also provide some protection of lead
surfaces by forming films with hydroxide, silicate, or phosphate, these films are prone to
sloughing when there are changes in flow or water quality or when LSLs are physically disturbed
during routine maintenance and repair activities. These dislodged scales can release metals that
may become entrapped in the interior (premise) plumbing, potentially increasing lead and
copper levels in the water (Schock, 2007b).
(2) Impacts on Wastewater
Because of problems with nutrient enrichment of surface waters in the United States, there has
been concern about adding phosphate-based corrosion inhibitors to drinking water because it
will increase the phosphorus loading to the wastewater treatment plant. Some wastewater
utilities have stringent limits on the amount of phosphorus that can be discharged to receiving
waters and remove it at the plant using biological and/or chemical treatment. Regardless of the
situation, it is important that systems communicate with wastewater treatment personnel and
evaluate potential impacts of adding phosphate-based corrosion inhibitors before making the
final treatment selection and setting the target dose.
Survey findings from 14 utilities showed that adding a phosphate-based corrosion inhibitor
increased the phosphorus load to the wastewater treatment plant by 10 to 35 percent, with a
median of 20 percent (Rodgers, 2014). Slightly less than half of the survey's respondents
removed phosphorus at the WWTP (Rodgers, 2014). This percentage might increase in the
future. Rodgers (2014) reported that in 2013, five states had statewide phosphorus limits for
lakes and reservoirs and in 2016, twelve states are expected to have such requirements.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 43
-------
Phosphorus can be removed at the WWTP using biological or chemical means. In the District of
Columbia, the Blue Plains WWTP added more ferric chloride to chemically remove phosphorus
after an orthophosphate corrosion inhibitor was added to drinking water; the additional cost
was minor compared to their overall operations budget (Cadmus Group, 2004). Wastewater
utilities can also use biological phosphorus removal or a combination of biological and chemical
removal techniques.
Prior to selecting a phosphate-based corrosion inhibitor, water systems and primacy agencies
should work with wastewater utility personnel to estimate the additional phosphorus load to
the WWTP and assess if the load could cause the plant to exceed permit limits or cause other
operational problems. Additional information on nutrient enrichment and phosphorus removal
strategies can be found in EPA's Nutrient Control Design Manual (USEPA, 2010b).
Use of a zinc orthophosphate corrosion inhibitor can increase zinc loading to the WWTP.
Schneider (2011) noted that, based on three case studies, most of the zinc in zinc
orthophosphate makes its way into the wastewater treatment stream. Although many systems
have successfully used zinc orthophosphate for corrosion control, zinc can inhibit biological
wastewater treatment processes, particularly nitrification and denitrification. Moreover, EPA
has set limits for zinc in processed sludge that is land applied (USEPA, 2004d). Schneider (2011)
notes that "The results of the utility case studies indicate that release of zinc in wastewater
residuals and/or receiving streams can be a concern for some utilities." Water systems and
primacy agencies should work with wastewater utility personnel to determine if additional zinc
loading may be an issue.
3.2.5 Technical Recommendations for Evaluating Feasibility and Cost (STEP 5)
Systems should consider operability, reliability, system configuration, and other site-specific
factors when evaluating CCT alternatives. In cases where more than one treatment option can
meet the OCCT definition of the rule,23 systems may want to consider cost factors including
costs for capital equipment, operations, and maintenance.
3.3 Setting the Target Dose and Water Quality
This section provides technical recommendations on setting the target dose and water quality
for pH/alkalinity/DIC adjustment, phosphate-based corrosion inhibitors, and silicate inhibitors.
3.3.1 pH/Alkalinity/DIC Adjustment
As explained previously, the pH, alkalinity, and DIC of the water have a significant influence on
lead and copper release. As a reminder, these three parameters are interrelated - if you know
two of them, you can estimate the third using the tables in Appendix B. The following
23 As noted in Chapter 1 and Appendix A, the LCR defines OCCT as "the corrosion control treatment that minimizes the lead and
copper concentrations at users' taps while insuring that the treatment does not cause the water system to violate any national
primary drinking water regulations." (§141.2)
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 44
-------
discussion provides technical recommendations for determining the target pH, alkalinity, and
DIG when controlling for lead only or lead and copper, and controlling for copper only.
To Control for Lead Only or Lead and Copper
The following technical recommendations can assist with the establishment of target pH,
alkalinity, and DIG ranges for controlling lead only, or both lead and copper release in drinking
water systems. Note that in general, lower pH levels can be used when controlling only for
copper release - see the next section for guidelines for those systems that do not have a lead
release problem, but are targeting copper corrosion control only. Note also that the guidelines
below are based on formation of adherent lead carbonate scales based on Pb(ll) chemistry24.
• The target pH should be 8.8 to 10. Systems with lead service lines that are not using a
corrosion inhibitor should consider increasing the pH to 9.0 or greater. Note that lower
pH values, particularly between 8.2 and 8.5, can result in poor buffer intensity of the
water (regardless of DIG levels) and wide swings in distribution system pH. See Section
2.3.4 for additional discussion of buffer intensity.
• Sufficient alkalinity and DIG are needed to form the protective scale and provide buffer
intensity, but too much can solubilize lead. These factors should be considered when
determining a target alkalinity/DIC range. The graph in Exhibit 2.3 can be used to
evaluate the effect of DIG on buffer intensity and identify a minimum DIG range for the
system's target pH. In general, the higher the pH is in the 8.8 to 10 range, the less DIG is
needed to buffer the water. Information on the relationship between DIG and lead
solubility is provided in Schock and Lytle (2011) for a modeled water. Lead solubility
increases (i.e., more lead is released into the water) with increasing DIG concentrations
above approximately 20 mg/L (as C). Schock and Lytle (2011, Figure 20-21) show
minimum lead solubility at DIG between 5 and 10 mg/L as C.
As a reminder, increasing the pH to 8.8 - 10 may cause calcium carbonate precipitation if
calcium is present, see Section 3.2.2 for additional discussion.
To Control for Copper Only
Adjustment of pH/alkalinity/DIC for copper control can generally be achieved at a lower target
pH (as low as 7.8) than the pH needed for lead control. Copper corrosion can be controlled at
even lower pH levels (i.e., between 7.0 and 7.8), but alkalinity and DIG become the limiting
factors. Schock and Lytle (2011) note that hard, high alkalinity ground waters are often
aggressive towards copper and hard to treat with pH adjustment because of calcium carbonate
precipitation potential. These waters may not be candidates for pH/alkalinity/DIC adjustment
and should consider orthophosphate or possibly removal of DIG through ion exchange,
membranes, or aeration.
24 For more information on Pb(ll) chemistry and also influences of Pb(IV) scale, see Sections 2.2.1 and 2.3.6.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 45
-------
3.3.2 Phosphate-Based Inhibitors
The effectiveness of orthophosphate treatment depends on many factors, including phosphate
dose, pH, DIG, and other constituents in the water (e.g., aluminum, iron, manganese). As noted
earlier, polyphosphates alone should not be used to treat for lead and copper; they are mainly
used to sequester iron and manganese. Special considerations for use of blended phosphate
are provided at the end of this section.
Conventional wisdom is that orthophosphate treatment for controlling lead and copper should
target residual concentrations of 0.33 to 1.0 mg/L as P (1.0 to 3.0 mg/L as PCU) at the tap when
pH is within the range of 7.2 to 7.8. Higher orthophosphate doses (1.0 - 1.2 mg/L as P, or 3 -
3.5 mg/L PC>4 and higher) may be needed under the following circumstances:
• To control lead release from LSLs.
• To control copper corrosion from new copper pipe.
• If the system has aluminum carry-over from alum coagulation and/or presence of iron,
manganese, and/or magnesium in finished water.
While the pH range of 7.2 to 7.8 is still considered optimal, systems should not automatically
reduce the pH of their water if it is 8 or higher when starting orthophosphate treatment.
Orthophosphate may be effective at pH as high as 9, although dose requirements may not be
the same as for pH from 7.2 to 7.8. Laboratory results suggest that less effective control of lead
release occurs between pH 8 and 8.5 than either above or below that range (Schock et al.,
1996; Miller, 2014). Systems should therefore avoid operating between pH 8 and 8.5, if
possible, to control for lead release. For copper, orthophosphate effectiveness is not strongly
affected by pH when pH is between 7 and 8; dose is much more important. The effectiveness of
orthophosphate for copper control increases with increasing pH above 8.
Systems and primacy agencies should also consider the DIG of finished water when determining
the target orthophosphate dose. In general, orthophosphate is more effective at low DIG (<10
mg C/L). Also, the pH is less important for lead control in low DIG waters.
Note that the target orthophosphate concentration is the level needed to control corrosion in
premise plumbing. Because orthophosphate will react with metals and other compounds, the
concentration leaving the treatment plant may need to be higher to achieve the target
concentration at the tap. In particular, aluminum (e.g., that was carried over from alum
coagulation) can react with orthophosphate and reduce the amount available in premise
plumbing. During start-up, systems should be prepared to adjust the dose at the treatment
plant to meet the target dose at the tap throughout the distribution system. See Chapter 5 for
additional recommendations on start-up of orthophosphate treatment.
Some systems have started orthophosphate treatment using a higher passivation dose,
followed by a lower maintenance dose for long-term treatment. Hill and Cantor (2011)
recommend that the passivation dose be 2 to 3 times higher than the target maintenance dose
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 46
-------
in order to build up a protective film as quickly as possible. The amount of time needed for the
initial passivation dose to form adequate scale is unknown, and will vary depending on the
system's specific water quality. Also, the maintenance dosage may initially need to be higher to
convert the existing scales on lead surfaces. Lead levels may continue to decline for years after
an optimal orthophosphate dose has been applied, due to the slow rate of scale formation.
Systems with LSLs should evaluate whether the orthophosphate dose is enough to passivate
disturbed LSLs in a timely manner. Routine maintenance or repairs such as water main
replacements, meter installations, service line and shut-off valve replacements, and leak repairs
may disrupt LSL scales and result in high lead levels. When evaluating the success of OCCT,
systems and primacy agencies should consider the impact of these physical disturbances on
lead levels at the tap (Del Toral et al., 2013). In addition, when establishing a maintenance
dosage, it is important to consider other factors such as homes with chronically low water use
that have LSLs. Ongoing diagnostic monitoring at these sites before and after treatment
installation or adjustment can provide useful information for establishing a proper maintenance
dose.
Special Consideration for Blended Phosphates
Blended phosphates have been used for corrosion control and to sequester iron and
manganese. Blended phosphates have been shown to be effective for reducing lead levels;
however, the lead corrosion scale may not be as robust as the scale created by orthophosphate
and, thus, may be more susceptible to physical disturbances and low water use conditions (Del
Toral et al., 2013; Wasserstrom et al., 2015). It is unclear if blended phosphates work well to
control copper corrosion, especially at high alkalinities.
The effectiveness of blended phosphates cannot be based on the orthophosphate
concentration in the blend for the following reasons:
• Blended phosphates control corrosion by creating a barrier film from the interaction of
calcium and aluminum in the bulk water with phosphorus containing compounds
(Wasserstrom et al., 2015). Thus, calcium and aluminum play a role in effectiveness.
• If the polyphosphate portion of the blend has a high affinity for sequestering lead or
copper, it may counteract the benefit of the orthophosphate portion in forming solid
lead and copper compounds.
The percent of orthophosphate in the blend can vary widely (from 5 to 70 percent (Hill and
Cantor, 2011)). Blended phosphate should contain a minimum orthophosphate concentration
of 0.5 mg/L as P (1.5 mg/L as PCu) as a starting point for evaluation. The orthophosphate ratio in
the blend and/or the dose may need to be increased to provide adequate lead control. In some
cases, however, simply adding more blended phosphate may not be effective because, if there
is excess polyphosphate available beyond what is bound up with other constituents in the
water, it can sequester the lead and copper. EPA recommends a demonstration study,
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 47
-------
additional monitoring, or both for systems that recommend blended phosphates to control lead
release.
3.3.3 Silicate Inhibitors
The effectiveness of silicate inhibitors depends on silicate level, pH, and DIG of the water.
Adding silicates can raise the pH, so lead and copper level reductions may occur due to an
increase in pH as well as passivation. In addition to providing lead and copper control, silicates
can sequester iron and manganese if the levels of these constituents are not too high (not
greater than 1 mg/L combined) (Schock et al., 1996; Schock et al., 2005).
Many systems have not considered silicate inhibitors for lead and copper control due to the
lack of research and field information proving its effectiveness, the estimated operating costs
and high dosage rates required, and the time it takes to reduce lead concentrations (Hill and
Cantor, 2011).The literature does report a successful case study for a small system in
Massachusetts that instituted chlorination and sodium silicate addition in three wells to address
LCR compliance and intermittent red water problems (Schock, Lytle, et al., 2005). An initial
silicate dosage rate of 25-30 mg/L was effective for reducing lead and copper levels by 55 and
87 percent, respectively, and raised the pH from 6.3 to 7.1. LCR compliance was achieved when
the silicate dosage rate was increased to 45-55 mg/L at two wells which raised the pH to 7.5. In
another study, Vaidya (2010) found that sodium silicate significantly reduced lead and copper
release in bench-scale studies using coupons from 30 to 35 year old distribution pipes.
Relatively high silicate doses (in excess of 20 mg/L) may be required to control lead release
(Schock, Lytle, et al., 2005). A startup dose of 24 mg/L is recommended, followed by a gradual
reduction after 60 days to a maintenance dose of 8 to 12 mg/L (Schock and Lytle, 2011; Hill and
Cantor, 2011). Chloride, calcium, and magnesium concentrations in the water can affect the
optimum dose (Hill and Cantor, 2011). A review of several case studies and literature reports
suggested that a pre-existing layer of corrosion products on the pipes was required in order for
silicate to properly form a protective layer, at least in copper pipes (LaRosa-Thompson et al.,
1997). Similar to phosphate-based inhibitors, it is important to maintain continuous dosing of
the silicate inhibitor to ensure effective corrosion control.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 48
-------
Chapter 4: Review of Corrosion Control Treatment Steps under the LCR
Corrosion control treatment (CCT) requirements under the Lead and Copper Rule (LCR) differ
depending on the system size (i.e., population served). Most systems serving more than 50,000
people were required to meet a series of deadlines beginning in 1993 to determine optimal
corrosion control treatment steps (OCCT) and install OCCT by January 1, 1997.25 Any system
that served 50,000 or fewer people at the time of the LCR, but that grew in population or
combined with another system so that they now serve more than 50,000 people (called
systems newly serving more than 50,000 people for the purposes of this document) must also
complete CCT steps. Because the regulatory deadlines for systems serving more than 50,000
people have passed, systems newly serving 50,000 people must follow the schedule for systems
serving 3,301-50,000 people (see Exhibit 4.1).26 Systems serving 50,000 or fewer people are not
required to conduct CCT steps under the LCR unless they exceed the lead and/or copper action
level (AL).
This chapter presents a review of CCT steps as required by the LCR along with additional
technical recommendations to systems and primacy agencies for the following categories of
systems:
• Those serving 50,000 or fewer people that exceed the lead and/or copper AL (Section
4.1).
• Systems newly serving more than 50,000 people (Section 4.2).
• Existing systems serving more than 50,000 people that previously installed CCT but have
subsequent action level exceedances (Section 4.2).
Chapter 5 follows with a review of LCR requirements and provides additional technical
recommendations for CCT installation, startup, follow-up monitoring, and long-term corrosion
control monitoring.
These sections are supported by the following appendices:
• Appendix D contains forms that can be used by systems to submit water quality data
and system information to the primacy agency.
• Appendix E contains OCCT recommendation forms for systems serving 50,000 or fewer
people.
• Appendix F summarizes tools available for conducting a corrosion control study.
25 All systems serving more than 50,000 people are required to conduct CCT steps unless they are deemed to have optimized
corrosion control under §141.81(b)(2) or(b)(3).
26 The schedule for completing CCT was clarified in the guidance manual, Lead and Copper Rule Monitoring and Reporting
Guidance for Public Water Systems (USEPA, 2010c) as footnote 1 in Exhibit 1-1. It specifies that a "system whose population
exceeds 50,000 after July 1,1994, must follow the schedule for medium-size systems, beginning with the requirement to
complete a corrosion control study".
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 49
-------
Systems and primacy agencies can use the OCCTevaluation templates to complete many of the
tables in the appendices related to their OCCT determination. The templates also provide an
opportunity for primacy agencies to customize forms and to enter specific dates for compliance
milestones.
As a reminder, requirements in this section are based on the LCR as of the date this document
was published. The Environmental Protection Agency (EPA) is considering changes to the LCR
that include changes to CCT requirements. See Section 1.1 for additional discussion.
4.1 Corrosion Control Treatment Steps for Systems Serving < 50,000 People
Exhibit 4.1 summarizes the required CCT actions and deadlines when a system serving 50,000 or
fewer people exceeds the lead and/or copper action level. The column furthest to the right
shows the related section or Chapter where relevant technical recommendations are provided
for the system or primacy agency.
It is important to note that in accordance with the LCR, systems serving 50,000 or fewer people
have no more than 6 months from the end of the monitoring period in which they had the AL
exceedance to recommend OCCT to their primacy agency. The primacy agency then determines
if a study is needed. If a study is not required, the primacy agency designates the OCCT within
24 months from the end of the monitoring period in which the system had the AL exceedance
for those serving 3,300 or fewer people or within 18 months for those serving 3,301 to 50,000
people. If the primacy agency requires a study, the system must complete the study within 18
months after the primacy agency required the study to be conducted, after which the primacy
agency designates the OCCT.
Also note that in accordance with the LCR, systems serving 50,000 or fewer people can
discontinue the steps outlined in Exhibit 4.1 whenever their 90th percentile levels are at or
below both ALs for two consecutive six-month monitoring periods. However, if these systems
then exceed the lead or copper AL, they must recommence completion of the applicable CCT
steps beginning with the first treatment step that was not completed in its entirety. The
primacy agency may require a system to repeat treatment steps previously completed by the
system where the Agency determines that this is necessary to properly implement the
treatment requirements.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 50
-------
Exhibit 4.1: Review of CCT Requirements and Deadlines for Systems Serving < 50,000 People
Requirement
STEP 1 : System exceeds the lead or
copper action level (AL).
STEP 2: System recommends
OCCT.
STEP 3: Primacy agency decides
whether system must perform a
corrosion control study. If system
must conduct a corrosion control
study, go to Step 5. If not, go to Step
4.
STEP 4: Primacy agency designates
OCCT for systems that were not
required to conduct a study. Go to
Step 7.
STEP 5: System completes
corrosion control study.3
STEP 6: Primacy agency designates
OCCT.3
STEP 7: System installs OCCT.
STEP 8: System conducts follow-up
sampling for 2 consecutive 6-month
periods.
STEP 9: Primacy agency designates
OWQPs.4
STEP 10: System conducts
continued WQP and lead and copper
tap sampling.
Timetable for Completing
Corrosion Control Treatment
Steps1
Within 6 months2
Within 12 months2
• Withinl 8 months2 for systems
serving 3,301-50,000 people
• Within 24 months2 for systems
serving < 3,300 people
Within 18 months after primacy
agency requires that such a study be
conducted
Within 6 months after completion of
StepS
Within 24 months after the primacy
agency designates such treatment
Within 36 months after the primacy
agency designates OCCT
Within 6 months after completion of
StepS
The schedule for required monitoring
is based on whether the system
exceeds an AL and/or complies with
OWQP ranges or minimum
Section Where
Technical
Recommendations Can
Be Found
Section 4.1.1
Section 4. 1.2
Section 4. 1.3
Section 4.1.4
Section 4.1.5
Section 5.1
Section 5.2
Section 5.3
Section 5.4
Notes:
1Systems serving 50,000 or fewer people can discontinue these steps whenever their 90th percentile levels are at or below both
action levels for two consecutive six-month monitoring periods. However, if these systems then exceed the lead or copper
action level, they must recommence completion of the applicable CCT steps.
2The required timetable (i.e., number of months) for completing Steps 2, 3, and 4 represent the number of months after the
end of the monitoring period during which the lead and/or copper action level was exceeded in Step 1.
3These steps only apply to systems thatwere required to conduct a corrosion control study.
4The primacy agency is not required to designate OWQPs for systems serving 50,000 or fewer people that no longer exceed
either action level after installing treatment. However, some primacy agencies have opted to do so.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
51
-------
4.1.1 System Serving < 50,000 People Makes OCCT Recommendation (STEP 2)
The LCR does not specify precisely how systems serving < 50,000 are required to develop their
OCCT recommendation. To help systems evaluate CCT alternatives and make their
recommendation, EPA has provided technical information and recommendations in Chapter 3.
Systems can use the forms in Appendix D to organize water quality data and other information
and forms in Appendix E to document the results of their assessment and submit their data and
recommendation to the primacy agency. Note that primacy agencies may also require a system
to collect additional data/information under §141.82(a).
4.1.2 Primacy Agency Determines Whether a Study Is Required for System Serving < 50,000
People (STEP 3)
Primacy agencies should review the data provided by the system (using forms in Appendices D
and E) for completeness. If data are not sufficient to make a CCT determination, the primacy
agency can request additional information from the system.
Once primacy agencies have reviewed the data and OCCT recommendation, they should
determine if a study is needed. Exhibit 4.2 provides a checklist to support the primary agency in
determining whether or not to require a CCT study. If more than two questions are answered
"Yes," the primacy agency should consider requiring a study. Importantly, as stated in EPA's LCR
guidance, EPA recommends that primacy agencies require all systems with lead service lines to
conduct a corrosion control study.
If the primacy agency does not require a study, their next step is to designate OCCT (go to
Section 4.1.3). Section 4.1.4 provides technical recommendations to support primacy agencies
in the event that a corrosion control study is required.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 52
-------
Exhibit 4.2: Recommended Checklist to Support Determination of the Need for a CCT Study
for Systems Serving < 50,000 People
Category
Presence of LSLs
pH stability
Iron Deposition Potential
Manganese Deposition
Potential
Calcium Carbonate
Deposition Potential
Chloride-to-Sulfate Mass
Ratio (CSMR) Issues
Source Water Changes in the
Future
Treatment Process Changes
Question
Does the System have lead service lines?1
Is the range of pH values measured at the Entry
Point > 1.0 pH units. (Range = Max entry point pH
- Min entry point)?
Is the range of pH values measured in the
Distribution System > 1.0 pH units. (Range = Max
pH-MinpH)?
Is average Entry Point iron > 0.3 mg/L?
Is average Distribution System iron > 0.3 mg/L?
Is average Entry Point manganese > 0.05 mg/L?
Is average Distribution System manganese > 0.05
mg/L?
Is average Hardness > 150 mg/L as CaCOs? Entry
point of distribution system values may be used.
Is the CSMR for either Entry Point or Distribution
System data >0.6? Use Average Chloride Level
divided by the Average Sulfate Level.
Did the system indicate that there may be source
water changes in the future?
Did the system indicate that there may be
treatment process changes in the future including
changes in coagulant?
Response (YES or NO)
1 If the system has LSLs, EPA guidance recommends the primacy agency to require a study.
4.1.3 Primacy Agency Designates OCCT for System Serving < 50,000 People (STEP 4)
As stated in the LCR, if the primacy agency determines that a study is not required, they must
either approve the OCCT option recommended by the system or designate alternative CCT(s)
from among those listed in §141.82(c)(l) (§141.82(d)). They must do this within 18 months
after the end of the monitoring period during which the system exceeds the lead or copper AL
for systems serving more than 3,300 people, and within 24 months for systems serving 3,300 or
fewer people. Primacy agencies can use information in Chapters 2 and 3 to help make this
determination.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
53
-------
The primacy agency must notify the system of its OCCT decision in writing and explain the basis
for the determination (§141.82(d)(2)). The primacy agency should work closely with the system
to determine the implementation approach and follow-up monitoring (See Chapters for
technical recommendations).
4.1.4 System Serving < 50,000 People Conducts Corrosion Control Study (STEP 5)
As stated in the LCR and summarized in Exhibit 4.1, systems are required to complete the
corrosion control study within 18 months of the primacy agency's determination that a study is
required. Exhibit 4.3 summarizes corrosion control study requirements for systems from the
LCR. Following the exhibit are (1) technical recommendations for primacy agencies on what
type of study to require, (2) technical recommendations for systems on study tools and other
considerations, and (3) technical recommendations for systems on corrosion control study
reporting.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 54
-------
Exhibit 4.3: Corrosion Control Study Requirements1
Corrosion Control
Study Component
LCR Requirements
Corrosion Control
Study Tools
Systems must evaluate the effectiveness of each CCT specified in §141.82(c)(l)
and, if appropriate, combinations of treatments using either pipe rig/loop
tests, metal coupon tests, partial-system tests, or analyses based on
documented analogous treatments with other systems of similar size, water
chemistry, and distribution system configuration (§141.82(a) and (c)(2)).
Monitoring
Requirements
Systems must measure the following water quality parameters in any tests
before and after evaluating the CCTs: Lead, copper, pH, alkalinity, calcium,
conductivity, orthophosphate (when an inhibitor containing a phosphate
compound is used), silicate (when an inhibitor containing a silicate compound
is used), and water temperature (§141.82(c)(3)).
Identification of
Constraints
Systems must identify all chemical or physical constraints that limit or prohibit
the use of a particular CCT and document such constraints with at least one of
the following (§141.82(c)(4)):
• Data and documentation showing that a particular CCT has adversely
affected other water treatment processes when used by another
water system with comparable water quality characteristics; and/or
• Data and documentation demonstrating that the water system has
previously attempted to evaluate a particular CCT and has found that
the treatment is ineffective or adversely affects other water quality
treatment processes.
Effects on Other
Treatment
Processes
Systems must evaluate the effect of the chemicals used for CCT on other
water quality treatment processes (§141.82(c)(5)).
Reporting
On the basis of an analysis of the data generated during each evaluation, the
water system must recommend to the primacy agency in writing the
treatment option that the corrosion control studies indicate constitutes OCCT
for that system. Systems must provide a rationale for their recommendation
along with all supporting documentation (§141.82(c)(6)).
1 Corrosion control studies may be required by the primacy agency. If they are, specific requirements for
conducting the studies apply regardless of system size. They are from the LCR and are current as of the date of this
publication. As a reminder, EPA is considering revising some aspects of the LCR. See Chapter 1 for additional
discussion.
(1) Technical Recommendations Regarding Type of Corrosion Control Study
There are several potential approaches to a CCT study. A study can be approached as a
"desktop study" based on documented analogous treatments with other systems of similar size,
water chemistry, and distribution system configuration, or a "demonstration study" using at
least one of the following study tools: pipe rig/loop tests, metal coupon tests, or partial system
tests. Systems serving 50,000 or fewer people may be able to satisfy CCT study requirements by
performing a desktop study of analogous systems. Exhibit 4.4 provides a recommended
checklist for primacy agencies to use to support the determination of whether to require
systems to perform a desktop or demonstration study.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
55
-------
Exhibit 4.4: Recommended Checklist to Support Primacy Agency Determination of When to
Require a Desktop or Demonstration Study for Systems Serving < 50,000 People
Question
Response
(YES or NO)
Recommended Next Step
1. Does the system have multiple sources of water?
2. Is the system planning future treatment changes?
3. Is the system planning future source water changes?
If the answer to at least two of the
first three questions is yes, go to
question 4. If not, consider
requiring the system to conduct a
desktop study.
4. Does the system serve 10,000 people or fewer?
If yes, consider re quiring a desktop
study unless lead service lines are
present. In that case, discuss the
most appropriate steps with the
system. If the population served is
greaterthan 10,000, consider
req uiring a demonstration study.
(2) Corrosion Control Study Tools
Appendix F describes tools that can be used for conducting desktop and demonstration
corrosion control studies. It includes the study tools required by the rule (analyses based on
documented analogous treatments (desktop study); or pipe rig/loop tests, metal coupon tests,
or partial-system tests (demonstration studies)) - along with other tools such as pipe scale
analysis and models that can be used to supplement the requirements. This list is not meant to
be exclusive - other tools might also be useful for determining the most effective CCT for the
system.
Note that systems conducting desktop studies must at a minimum evaluate analogous
treatments at other systems of similar size, water chemistry, and distribution system
configuration to meet the corrosion control study requirements of the LCR.
(3) Corrosion Control Study Reporting
The system must provide the primacy agency with its recommended OCCT option along with
the rationale for its recommendation and supporting documentation as described §141.82(c)(l)
- (6). The system must also identify all chemical or physical constraints that limit or prohibit the
use of a particular corrosion control treatment and document such constraints with at least one
of the following (§141.82(c)(4) and (c)(6)):
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
56
-------
• Data and documentation showing that a particular CCT has adversely affected other
water treatment processes when used by another water system with comparable water
quality characteristics; and/or
• Data and documentation demonstrating that the water system has previously
attempted to evaluate a particular CCT and has found that the treatment is ineffective
or adversely affects other water quality treatment processes.
The system must also evaluate the effect of the chemicals used for CCT on other water quality
treatment processes (§141.82(c)(5) and (c)(6)).
EPA recommends that the system submit to the primacy agency a report that includes the
required information identified above and additional data and analyses as follows:
• Options for addressing identified constraints, so that the system would be able to
achieve and maintain OCCT, meet other water quality goals, and remain in compliance
with all applicable drinking water regulations.
• The corrosion control study's conclusion (i.e., the recommended treatment) and a target
level for pH, alkalinity, and corrosion inhibitors (if used).
• Recommended operating ranges for key parameters (pH, alkalinity and inhibitor (if
used)) both at the entry point and in the distribution system.
• Treatment chemicals and dosages that will be used to maintain OCCT, recommendations
for quality assurance testing of chemicals, and follow-up monitoring recommendations.
• The system's plan for treatment start-up (see Sections 3.3 and 5.1 for technical
recommendations for start-up of pH/alkalinity/dissolved inorganic carbon (DIC)
adjustment and phosphate-based corrosion inhibitor treatment).
Exhibit 4.5 and Exhibit 4.6 provide possible outlines for desktop and demonstration study
reports, respectively.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 57
-------
Exhibit 4.5: Possible Outline for a Desktop Study Report
Executive Summary
I. Introduction
II. Project Background
III. Review of Existing Information
A. Water System Information (provide a system schematic)
B. Water Quality Data
1. Raw water
2. Entry Point
3. Distribution system
4. Tap
C. Pipeline and Plumbing Materials
D. Summary of Water Quality Complaints
E. Analogous System Information
IV. Potential Causes of Elevated Lead and/or Copper Levels in the System
V. Identification and Assessment of Corrosion Control Alternatives
VI. Evaluation of Corrosion Control Alternatives
A. Performance
B. Constraints
C. Recommended OCCT
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 58
-------
Exhibit 4.6: Possible Outline for a Demonstration Study Report
Executive Summary
I. Introduction
II. Project Background
III. Review of Existing Information
A. Water System Information (provide a system schematic)
B. Water Quality Data
1. Raw Water
2. Entry Point
3. Distribution System
4. Tap
C. Pipeline and Plumbing Materials
D. Summary of Water Quality Complaints
E. Analogous System Information
IV. Special Studies
A. Bench Scale Studies
1. Methods and Materials
2. Results
B. Pipe Loop Studies
1. Methods and Materials
2. Results
C. Partial System Testing
1. Methods and Materials
2. Results
V. Potential Causes of Elevated Lead and/or Copper Levels in the System
VI. Identification and Assessment of Corrosion Control Alternatives
VII. Evaluation of Corrosion Control Alternatives
A. Performance
B. Constraints
C. Recommended OCCT
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 59
-------
4.1.5 Primacy Agency Designates OCCT for Systems Serving < 50,000 People (STEP 6)
Exhibits 4.7 and 4.8 provide technical recommendations for primacy agencies for their review
of desktop and demonstration study reports, respectively. Primacy agencies should refer to
Chapter 2 for background on sources of lead and copper and impacts of water quality and
physical system characteristics on lead and copper release. The information in Chapter 3 can
also be used as a reference when evaluating the recommended OCCT option.
Exhibit 4.7: Recommendations for Primacy Agency Review of Desktop Study
1) Make sure all components of a desktop study are included in the report
—> If they are not, coordinate with system to complete study and check against recommended
outline of required components for desktop studies.
—> If they are, continue.
2) Evaluate raw, entry point, and distribution system water quality information
—> Evaluate key water quality parameters (pH, alkalinity, conductivity, hardness, other anions and
cations) and their impact on lead and/or copper release to water (entry point and distribution
system) and treatability (raw water).
—> Evaluate differences in entry point versus distribution system data for key water quality
parameters, particularly variations in pH and DIG.
3) Review regulatory tap monitoring data for lead and copper and other supplemental lead and
copper data (e.g., from special studies by universities).
—> Assess 90th percentile lead and copper levels and that sites selected for regulatory monitoring
meet the criteria in the LCR.
—> Assess available supplemental lead and copper data, if available.
4) Review materials and customer complaint history
—> Determine primary sources of lead and copper in drinking water (lead pipe, lead solder, brass,
copper pipe).
—> Identify other materials in the system that may be impacted by CCT (unlined cast iron pipe, AC
pipe, etc.)
5) Review analogous system information
—> Ensure that systems described are similar in source, water quality, and materials profiles
6) Evaluate causes of elevated lead and/or copper levels
—> Use water quality and materials information along with corrosion theory to determine primary
causes of elevated lead and/or copper levels
7) Evaluate potential CCT alternatives identified in study
—> Evaluate if alternatives have been compared with respect to ability to reduce lead and/or
copper levels in the system (performance) and the effects that additional CCT will have on
water quality parameters (WQPs) and on other water quality treatment processes.
8) Evaluate final recommended OCCT and approve installation if warranted.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 60
-------
Exhibit 4.8: Recommendations for Primacy Agency Review of Demonstration Study
1) Make sure all components of a demonstration study are included in the report
—> If they are not, coordinate with system to complete study and check against recommended
outline of required components for desktop studies.
—> If they are, continue.
2) Evaluate raw, entry point, and distribution system water quality information
—> Evaluate key water quality parameters (pH, alkalinity, conductivity, hardness, other anions and
cations) and their impact on lead and/or copper release to water (entry point and distribution
system) and treatability (raw water).
—> Evaluate differences in entry point versus distribution system data for key water quality
parameters, particularly variations in pH and DIG.
3) Review regulatory tap monitoring data for lead and copper and other supplemental lead and copper
data (e.g., from special studies by universities).
—> Assess 90th percentile lead and copper levels and that sites selected for regulatory monitoring
meet the criteria in the LCR
—> Assess available supplemental lead and copper data, if available.
4) Review materials and customer complaint history
—> Determine primary sources of lead and copper in drinking water (lead pipe, lead solder, brass,
copper pipe).
—> Identify other materials in the system that may be impacted by CCT (unlined cast iron pipe, AC
pipe, etc.)
5) Review analogous system information
—> Ensure that systems described are similar in source, water quality, and materials profiles
6) Evaluate causes of elevated lead and/or copper levels
—> Bench scale/Pipe Rack: Ensure that materials evaluated are similar to lead and copper source
materials in system. Also ensure that water quality conditions are similar to system conditions.
For pipe rack studies, ensure that study was conducted long enough for stable scales to form on
the pipes.
—> Scale Analyses: Identify if representative pipe specimens were gathered in the field
(representative of lead and/or copper source material that is contributing to elevated lead and
copper levels in the water) and that scale analyses were completed using appropriate methods
with proper QA/QC.
—> Partial System Testing: Testing area should be selected to represent sites with elevated lead
and/or copper levels similar to those used for regulatory compliance sampling under the LCR.
Study should continue long enough for CCT to be effective.
—> Other: Any additional sampling should be conducted at sites representative of sites used for LCR
compliance sampling.
—> Results from special studies should be used to inform recommendations on causes of elevated
lead and/or copper levels, performance of potential treatment alternatives, and constraints and
secondary impacts that may occur with implementation of CCT.
7) Evaluate potential CCT alternatives identified in study
—> Evaluate if alternatives have been compared with respect to their abilities to reduce lead and/or
copper levels in the system (performance) and the effects that additional CCT will have on WQPs
and on other water quality treatment processes.
8) Evaluate final recommended OCCT and approve installation if warranted.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 61
-------
4.2 Corrosion Control Steps for Systems Serving > 50,000 People
As noted earlier in this chapter, most systems serving more than 50,000 people were required
to install OCCT by January 1, 1997. Systems that served 50,000 people or fewer at that time
may have since experienced population growth, combined with other systems, and/or made
other changes so that their new population served is more than 50,000 people. These systems
then become subject to the requirements for large systems, including the specific CCT steps
applicable to large systems unless they are deemed to have optimized CCT under §141.81(b)(2)
or(b)(3).
Exhibit 4.9 summarizes the required actions and deadlines for CCT steps for these systems. It
also shows the related section in this document where additional technical recommendations
are provided for the system or primacy agency. Those systems serving more than 50,000 people
with existing CCT but that have subsequent lead or copper action level exceedances should
follow the steps in Exhibit 4.9 in addition to complying with lead service line replacement
requirements in §141.84. The LCR does not include a schedule for CCT adjustment; instead, one
will likely be set by the primacy agency.
Exhibit 4.9: Summary of CCT Requirements and Deadlines for Systems Serving > 50,000
People (§141.81(e))
Requirement1
STEP 1: System completes
Corrosion Control Study.
STEP 2: Primacy agency
designates OCCT.
STEP 3: System installs
OCCT.3
STEP 4: System conducts
follow-up monitoring for 2
consecutive 6-month periods.
STEP 5: Primacy agency
designates OWQPs.
STEP 6: System conducts
continued WQP and lead and
copper tap monitoring.
Timetable for Completing Corrosion
Control Treatment Steps
Within 18 months after the end of the
monitoring period which triggered a
study2
Within 6 months after study is completed
Within 24 months after primacy agency's
decision regarding type of treatment to
be installed
Within 36 months after primacy agency
designates OCCT
Within 6 months of Step 4
The schedule for required monitoring is
based on whether the system exceeds
an AL and/or complies with OWQP
ranges or minimums
Corresponding Section of
this Document
Section 4.2.1
Section 4.2.2
Section 5.1
Section 5.2
Section 5.3
Section 5.4
1This schedule applies to systems newly serving > 50,000 people that are installing CCT. Because the regulatory deadlines for
systems serving more than 50,000 people have passed, systems newly serving 50,000 people must follow the schedule for
systems serving 3,301-50,000 people
2ln other words, at the end of the monitoring period when the system became a system serving > 50,000 people.
3 For systems with existing CCT, this step would involve adjusting CCT.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
62
-------
4.2.1 Systems Serving >50,000 People Conduct a Corrosion Control Study (STEP 1)
Corrosion control study requirements (e.g., study tools, identification of constraints, reporting)
were summarized previously in this Chapter in Exhibit 4.3.
In addition to the corrosion control study and OCCT recommendation, EPA recommends that
systems provide their primacy agencies with the water quality and other system-specific
information as identified in Appendix D. Primacy agencies may also require a system to collect
this additional data/information as per §141.82(a) and (d)(2). The recommended data and
information collection forms in Appendix D can be customized for individual systems. Data
should be sufficient to characterize raw water, treated water quality (entry point), distribution
system water quality, and lead and copper in tap samples. The frequency of data collection
should be based on the complexity of the system and how water quality may vary over time
and location. Systems should be encouraged to provide multiple years of data that represent
different seasons (e.g., quarterly data). Water quality samples should be collected as close in
time as possible to lead and copper tap samples. Primacy agencies may be able to verify
information using the system's latest sanitary survey report. Recommendations for reviewing
water quality data are provided in Section 3.2.1.
As noted in Exhibit 4.3, systems performing corrosion control studies must use either pipe
rig/loop tests, metal coupon tests, partial-system tests, or analyses based on documented
analogous treatments with other systems of similar size, water chemistry, and distribution
system configuration for their CCT study. Because there is less likelihood of truly analogous
systems once the population served is more than 50,000 people, EPA recommends that these
systems use one of the demonstration study tools (i.e., pipe rig/loop, metal coupon, or partial-
system test) to meet CCT requirements. Additional desktop and demonstration study tools can
be used to supplement the requirements- see Appendix F for a description of the required and
additional CCT study tools. Systems may also find the recommended approach for selecting
OCCT (provided in Chapter 3) helpful as a screening tool for identifying which treatments
warrant further study.
The system must provide the primacy agency with its recommended OCCT option along with
the rationale for its recommendation and supporting documentation as described §141.82(c)(l)
- (6). The system must also identify all chemical or physical constraints that limit or prohibit the
use of a particular corrosion control treatment and document such constraints with at least one
of the following (§141.82(c)(4) and (c)(6)):
• Data and documentation showing that a particular CCT has adversely affected other
water treatment processes when used by another water system with comparable water
quality characteristics; and/or
• Data and documentation demonstrating that the water system has previously
attempted to evaluate a particular CCT and has found that the treatment is ineffective
or adversely affects other water quality treatment processes.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 63
-------
The system must also evaluate the effect of the chemicals used for CCT on other water quality
treatment processes (§141.82(c)(5) and (c)(6)).
EPA recommends that the system submit to the primacy agency a report that includes the
required information identified above and additional data and analyses as follows:
• Options for addressing identified constraints, so that the system would be able to
achieve and maintain OCCT, meet other water quality goals, and remain in compliance
with all applicable drinking water regulations.
• The corrosion control study's conclusion (i.e., the recommended treatment) and a target
level for pH, alkalinity, and corrosion inhibitors (if used).
• Recommended operating ranges for key parameters (pH, alkalinity and inhibitor (if
used)) both at the entry point and in the distribution system.
• Treatment chemicals and dosages that will be used to maintain OCCT, recommendations
for quality assurance testing of chemicals, and follow-up monitoring recommendations.
• The system's plan for treatment start-up (see Sections 3.3 and 5.1 for technical
recommendations for start-up of pH/alkalinity/DIC adjustment and phosphate-based
corrosion inhibitor treatment).
Exhibit 4.5 and Exhibit 4.6, presented earlier in this section, provide possible outlines for
desktop and demonstration study reports, respectively.
4.2.2 Primacy Agency Reviews the Study and Designates OCCT for System Serving > 50,000
People (STEP 2)
Primacy agencies can use the checklist in Exhibit 4.8 in Section 4.1.5 to support their review of
the study's design and findings. Primacy agencies should refer to Chapter 2 for background on
sources of lead and copper and impacts of water quality and physical system characteristics on
lead and copper release. The information in Chapter 3 can also be used as a reference when
evaluating the recommended OCCT option.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 64
-------
Chapter 5: Requirements and Technical Recommendations for OCCT Start-Up
and Monitoring
This chapter picks up where Chapter 4 ended - after the primacy agency designates optimal
corrosion control treatment (OCCT), the system will install OCCT and conduct follow-up
monitoring. The primacy agency will then designate optimal water quality parameters
(OWQPs). This chapter is organized as follows:
• Section 5.1 provides technical recommendations for systems on corrosion control
treatment (CCT) start-up.
• Section 5.2 discusses required and recommended elements of follow-up monitoring
during the first year of OCCT operation.
• Section 5.3 provides requirements and technical recommendations for primacy agencies
on evaluating OCCT and setting OWQPs.
• Section 5.4 provides requirements and technical recommendations for comprehensive
long-term monitoring for corrosion control.
Systems are encouraged to refer to the document Lead and Copper Rule Monitoring and
Reporting Guidance for Public Water Systems (USEPA, 2010c) for direction on follow-up and
continued lead and copper tap and water quality parameter (WQP) monitoring.27
5.1 CCT Start-up
In accordance with the Lead and Copper Rule (LCR), after the primacy agency designates OCCT,
the system has 24 months to install it (§141.81(e)(5)).28 During that time, systems may be
adding a new chemical (i.e., a corrosion inhibitor) to the finished water and/or adjusting the
finished water pH by adding a new chemical or increasing the dose of an existing chemical.
These types of changes can have temporary adverse impacts on water quality in the
distribution system (e.g., red water from sloughing of corrosion scale, microbial changes).
Therefore, the Environmental Protection Agency (EPA) has provided recommendations in the
next two sections for systems to consider when starting pH/alkalinity/dissolved inorganic
carbon (DIC) adjustment (5.1.1) and when adding a corrosion inhibitor (5.1.2) to help minimize
these potential adverse effects.29 EPA recommends that systems discuss corrosion control
treatment start-up procedures with their primacy agency when the agency is designating OCCT.
Additional recommendations for CCT start-up can be found in Hill and Cantor (2011).
27 This guidance is available at http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100DP2P.txt.
28 The required time period for installing OCCT (24 months) applies to systems serving < 50,000 people and systems newly
serving > 50,000 people. The schedule for CCT adjustment for systems that already have CCT is not provided in the LCR. The
primacy agency will likely set a schedule for systems serving > 50,000 people that previously installed CCT but have a
subsequent action level exceedance.
29 Silicate-based inhibitors are not included here because information on their use and effectiveness continues to be limited and
more research is needed.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 65
-------
5.1.1. Start-up of pH/Alkalinity/DIC Adjustment
Changes in pH/alkalinity/DIC result in a new water quality equilibrium to be established in the
distribution system. To minimize adverse impacts (e.g., sloughing of corrosion scale, aesthetic
issues), systems should consider raising the pH in increments, e.g., by 0.2 or 0.3 pH units over a
12-month period, or increasing the pH incrementally every 3 months (USEPA, 2007b; MOE,
2009). The approach will be system specific, but consideration should be given to the amount of
lead and/or copper reduction that is needed and the potential for secondary impacts as the
distribution system equilibrates. The amount of time needed to see results from
implementation of pH adjustment will also be system specific. Some systems have seen lead
and/or copper reduction within a matter of days following pH adjustment (MOE, 2009);
however, other systems have required up to a year to produce a new stable target pH in the
distribution system (MWRA, 2010).
5.1.2 Start-up of Phosphate-Based Corrosion Inhibitors
When starting orthophosphate treatment, some systems have gradually increased their
orthophosphate doses over time. For example, in a partial distribution system test, an initial
orthophosphate dose of 1 mg/L as PCU (~0.3 mg/L as P) was gradually increased to 3 mg/L as
PC>4 (~1 mg/L as P) over seven months. At three weeks, the orthophosphate concentration
reached the target dose at the far ends of the system (MOE, 2009).
Some systems have started orthophosphate treatment with a higher passivation dose, then
after a certain time period, switched to a lower maintenance dose for long-term corrosion
control. For example, Hill and Cantor (2011) recommend starting inhibitors at 2 to 3 times the
maintenance dose in order to more quickly establish a passivating layer. See Section 3.3.2 for
technical recommendations related to passivation and maintenance doses.
5.2 Follow-up Monitoring during First Year of Operation
The LCR requires systems to conduct two types of follow-up monitoring during the two
consecutive, 6-month periods directly following installation of OCCT (§141.81(d)(5) and (e)(6)):
• Lead and copper tap monitoring; and
• WQP monitoring.
The next two sections summarize follow-up monitoring requirements and recommendations.
Systems can use the forms in Appendix G and the forms in the OCCT evaluation templates to
document the results of follow-up monitoring.
As will be discussed in Section 5.3, the primacy agency will use the results of follow-up lead and
copper tap monitoring and results from samples collected prior to the system's installation of
CCT to determine if the system has properly installed and operated OCCT and to set OWQPs.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 66
-------
5.2.1 Follow-up Lead and Copper Tap Monitoring
All systems, regardless of size, must conduct two consecutive six-month rounds of follow-up
lead and copper tap monitoring at the same number of sites as required for routine monitoring
under the LCR (§141.86(c) and (d)(2); see Exhibit 5.1).
Exhibit 5.1: Required Number of Sites for Follow-up Lead and Copper Tap Monitoring
Population Served
<100
101-500
501-3,300
3,301 - 10,000
10,001 - 100,000
>100,000
Required Number of Sites1
5
10
20
40
60
100
1. §141.86(c)and(d)(2)
Note: The number of sites is the same as the number of sites required for routine monitoring.
EPA recommends that systems with lead service lines (LSLs) and their primacy agencies
consider collecting special tap samples during follow-up monitoring to evaluate the lead
released directly from the LSLs. Systems can conduct premise plumbing profiles (see Appendix
C for more information), or ask homeowners to collect samples that would capture water from
within the LSL for lead analysis. Dissolved and particulate lead should be measured for these
special samples. In addition, primacy agencies may wish to consider data from chronically low
flow homes and homes with LSL disturbances when evaluating the effectiveness of the CCT.30
5.2.2 Follow-up WQP Monitoring
Requirements for WQP follow-up monitoring and recommendations for additional monitoring
are summarized in Exhibits 5.2 and 5.3, respectively. Required WQP follow-up monitoring must
be conducted at entry points to the distribution system and at tap monitoring locations. Entry
point samples must be collected from locations that are representative of each source after
treatment. Systems with multiple sources that are combined before distribution must sample at
each entry point to the distribution system during periods of normal operating conditions to
allow the sample to be representative of all sources being used (§141.87(a)(l)(ii); USEPA
2010c). Tap samples must be representative of water quality throughout the distribution
system taking into account the number of persons served, the different sources of water, the
different treatment methods employed by the system, and seasonal variability. Tap monitoring
locations can be the sites used for coliform monitoring or the sites used for lead and copper tap
monitoring (§141.87(a)(l)(i)).
30 All lead and copper tap sample results from the system's sampling pool collected within the monitoring period must be
included in the 90th percentile calculation along with any samples where the system is able to determine that the site selection
criteria in §141.86(a)(3)-(8) for the sampling pool are met. Other lead and copper tap data such as from customer requested
sampling, investigative sampling, and special studies must be submitted to the primacy agency (USEPA, 2004e; §141.90(g)).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 67
-------
As summarized in Exhibit 5.2, the LCR requires one sample from each entry point at least once
every two weeks for:31
• PH;
• When alkalinity is adjusted, a reading of the dosage rate of the chemical used to adjust
alkalinity and the concentration of alkalinity; and
• When an inhibitor is used, a reading of the dosage rate of the inhibitor used and the
concentration of orthophosphate or silicate (whichever is used).
AND
Two sets of samples from a specified number of taps (see Exhibit 5.3) during both consecutive
6-month monitoring periods for:
• PH;
• Alkalinity;
• Calcium, when calcium carbonate stabilization is used;
• Orthophosphate, when a phosphate-based inhibitor is used; and
• Silica, when a silicate-based inhibitor is used.
Note that the LCR requires systems serving 50,000 or fewer people to conduct follow-up WQP
monitoring only during monitoring periods in which they have a lead and/or copper action level
exceedance (§141.87(c)). Monitoring is not required if these systems no longer exceed the
action level after installing OCCT. However, EPA recommends that primacy agencies consider
requiring follow-up WQP monitoring during the first year after OCCT installation regardless of
whether the system exceeds the action level in order to demonstrate that the treatment is
operating properly.
31 Except ground water systems that have primacy agency approval to limit this monitoring to representative sites.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 68
-------
Exhibit 5.2: Follow-up WQP Monitoring Requirements1 and Recommendations
Type
Entry point
Tap (Distribution
system
samples)5
Parameters
pH, alkalinity dosage
rate and concentration,2
inhibitor dosage rate
and orthophosphate or
silicate concentration
(whichever is used)3
pH, alkalinity,
orthophosphate or
silica3, calcium6
Required 1
Number of
Sites
At each entry
point4
Number of
sites based
on system
size, See
Exhibit 5.3
Frequency of
Sampling
At least once
every two
weeks
At least twice
every six
months (4
sample periods)
Recommended
Number of
Sites
No Change
At more
taps than
required.
See Exhibit
5.3.
Frequency of
Sampling
No Change
All parameters:
Monthly
Required for all systems serving more than 50,000 people (§141.87(c)). Systems serving 50,000 or fewer people are required
to conduct follow-up WQP monitoring during any monitoring period in which they exceed either action level or if required by
the primacy agency (§141.81(b) and §141.87(c)). Follow-up monitoring occurs during the 12-month period following OCCT
installation (§141.81(e)(6) and §141.87(c)).
2Required at entry point locations if alkalinity is adjusted as part of corrosion control (§141.87(c)(2)(ii)).
Required if an inhibitor is used. Monitoring for orthophosphate is only required if a phosphate-containing inhibitor is used
(§141.87(c)(l)(iii) and (c)(2)(iii). Monitoring for silica is only required if a silicate-containing inhibitor is used (§141.87(c)(l)(iv)
4Ground water systems can limit entry point monitoring to representative sites with approval from their primacy agency
(§141.87(c)(3)).
5WQP tap samples are collected at locations that are representative of the water quality throughout the distribution system.
Systems may sample from sites used for coliform monitoring (§141.87(a)).
6Required if calcium carbonate stabilization is used (§141.87(c)(l)(v)).
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
69
-------
Exhibit 5.3: Required and Recommended Number of Sites for Follow-up WQP Tap Monitoring
Population Served
<100
101-500
501 - 3,300
3,301 - 10,000
10,001 - 50,000
50,001 - 75,000
75,001 - 100,000
100,001 - 500,000
500,001 - 1,000,000
>1,000,000
Required Number of
Sites1
1
1
2
3
10
10
10
25
25
25
Recommended Number
Sites
2
5
10
15
20
25
30
40
50
>50
Required for all systems serving more than 50,000 people (§141.87(c)).
For follow-up WQP tap monitoring, two samples must be collected from the required number
of sites shown in Exhibit 5.3 during both six month monitoring periods specified in
§141.86(d)(2) (§141.87(c)(l)). As shown in Exhibit 5.2, EPA recommends that systems and
primacy agencies consider increasing the frequency of WQP tap sampling to monthly. More
frequent monitoring is recommended to capture seasonal variations and influences of
temperature on treatment effectiveness.
EPA also recommends that systems and primacy agencies consider follow-up WQP tap
monitoring at more locations than required by the LCR (See Exhibit 5.3). Collecting WQP
samples at an increased number of tap monitoring locations is especially important for systems
that experience fluctuations in distribution system water quality. In particular, pH variations can
have a large impact on corrosion control treatment effectiveness. The pH can fluctuate widely
in systems with low buffering capacity, high water age (e.g., in dead end areas), high
microbiological activity, and in systems that experience nitrification. It is important that
distribution system monitoring represents all pressure and water quality zones to adequately
assess treatment effectiveness in all parts of the system.
Primacy agencies and systems may want to consider additional monitoring for iron, manganese,
chloride, sulfate, hardness, calcium, total dissolved solids (TDS), and/or oxidation-reduction
potential (ORP) if they believe that these parameters may change or were not adequately
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
70
-------
characterized prior to CCT installation.32 Primacy agencies can use the forms in Appendix G and
electronic versions in the OCCTEvaluation Templates to document additional follow-up
monitoring requirements for systems.
Follow-up WQP samples from the entry point and tap sites should be collected as close in time
as possible to when lead and copper tap samples are collected. EPA recommends that systems
begin data collection approximately one month after OCCT is installed.
5.3 Evaluating OCCT and Setting Optimal Water Quality Parameters
Primacy agencies are required to evaluate results of follow-up tap and water quality monitoring
and results collected prior to the installation of CCT to determine whether the system has
properly installed and operated the OCCT and to designate (§141.82(f)):
• A minimum value or a range of values for pH measured at each entry point to the
distribution system;
• A minimum pH value, measured in all tap samples, that is equal to or greater than 7.0,
unless the primacy agency determines that meeting a pH level of 7.0 is not
technologically feasible or is not necessary for the system to optimize corrosion control;
• If alkalinity is adjusted as part of OCCT, a minimum concentration or a range of
concentrations for alkalinity, measured at each entry point to the distribution system
and in all tap samples;
• If a corrosion inhibitor is used, a minimum concentration or a range of concentrations
for the inhibitor, measured at each entry point to the distribution system and in all tap
samples, that the primacy agency determines is necessary to form a passivating film on
the interior walls of the pipes of the distribution system; and
• If calcium carbonate is used as part of corrosion control, a minimum concentration or a
range of concentrations for calcium, measured in all tap samples.
Primacy agencies can designate values for additional water quality control parameters (e.g.,
free chlorine residual, conductivity, ORP) that reflect optimal corrosion control for the system
(§141.82(f)).
EPA recommends that primacy agencies also use results of follow-up monitoring to further
evaluate the OCCT and recommend re-evaluation if the results of the treatment are not what
were predicted.
Note that the LCR includes a provision (§141.82(h)) for primacy agencies to modify their
determination of OCCT or OWQP designations where they conclude that such change is
necessary to ensure that the system continues to optimize CCT. A request for modification can
also be in response to a written request with supporting documentation from a system or other
32 Under §141.82(f), the primacy agency may designate values for additional water quality control parameters determined by
the primacy agency to reflect optimal corrosion control for the system. The primacy agency must notify the system in writing of
these determinations and explain the basis for its decisions.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 71
-------
interested party. The revised determination must be in writing, and include the new treatment
requirements, the basis for the primacy agency's decision, and an implementation schedule for
completing the treatment modifications.
Appendix G provides technical recommendations for primacy agencies to consider when
designating OWQPs for pH/alkalinity/DIC adjustment, orthophosphate treatment, blended
phosphate treatment, and use of a silicate inhibitor based on data gathered during the follow-
up monitoring.
A recent publication by Cornwell et al. (2015) examined the use of control charts as a diagnostic
tool for determining parameter variability and setting acceptable ranges. This approach may be
useful to primacy agencies and systems for controlling WQPs and determining when treatment
adjustment is needed to bring a parameter back within its goal range.
5.4 Required and Recommended Long-Term Corrosion Control Monitoring
This section describes WQP monitoring required by the LCR once the primacy agency has set
OWQPs. It also provides technical recommendations for additional data collection and tracking
that could be used to enhance a system's understanding of CCT effectiveness. For the purposes
of this document, the combination of required WQP monitoring and additional recommended
monitoring is referred to as "Long-term corrosion control monitoring".
Required WQP Monitoring
Systems must collect two sets of samples every six months (§141.87(c)(l) and (d)) at the
number of WQP tap sampling sites specified for the system size in §141.87(a)(2) (see Exhibit
5.3) for:
• PH;
• Alkalinity;
• Calcium, when calcium carbonate stabilization is used;
• Orthophosphate, when a phosphate-based inhibitor is used; and
• Silica, when a silicate-based inhibitor is used.
AND
One set of samples at each entry point (except those ground water systems that can limit entry
point monitoring to representative sites) at least once every two weeks for:
• PH;
• When alkalinity is adjusted, a reading of the dosage rate of the chemical used to adjust
alkalinity and the concentration of alkalinity; and
• When an inhibitor is used, a reading of the dosage rate of the inhibitor used and the
concentration of orthophosphate or silicate (whichever is used).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 72
-------
Systems that meet their OWQPs for a specified period of time can qualify for reduced WQP
monitoring that allows for fewer and less frequent monitoring at tap locations (§141.87(e)). The
LCR does not allow reduced monitoring for WQP samples collected at entry points. Refer to
Section III.H in the Lead and Copper Rule Monitoring and Reporting Guidance for Public Water
Systems (USEPA, 2010c) for additional information.
Technical Recommendations for Additional Monitoring
Additional monitoring could include monitoring for additional WQPs, customer complaint
tracking, and monitoring associated with lead source replacement programs.
In addition to required WQP monitoring, systems may want to consider analyzing other water
quality parameters that can affect lead and copper release. These may include ORP, ammonia,
chloride, sulfate, aluminum, iron, and manganese. See Section 2.3 for discussion of how these
water quality parameters influence corrosion.
Customer complaints provide useful information on conditions occurring at customer's taps.
Common complaints include red water (iron) and darker tint to the water (manganese), which
can indicate an increase in source water levels of iron and manganese or sloughing of scale
from cast iron pipe. Complaints of taste/odor issues (earthy or musty flavor) can indicate
changes in natural organic matter (NOM) due to algae blooms. Systems can obtain important
information from customer complaints of blue water or a metallic taste, which can indicate
copper corrosion (customers can begin to notice the taste from copper at concentrations of 3 -
10 mg/L per Dietrich et al., 2008), It is important to note that while customer complaint records
can provide information on copper corrosion, lead at levels in drinking water has no taste or
color.
Systems should consider additional monitoring to evaluate the effectiveness of lead source
replacement programs. Monitoring should occur before and after the lead source has been
removed (from the service line or faucet, for example) at the tap or directly from the service
line. Both total and dissolved lead should be analyzed to determine the percentages of
particulate and dissolved lead. Replacement of lead sources, such as lead service lines, may
increase lead levels (especially particulate lead levels) for a period of time due to the physical
disturbance of the system (Sandvig et al., 2008; Muylwyk et al., 2009; Swertfeger et al., 2006;
Del Toral et al., 2013). Some disturbances, along with other factors, may elevate lead levels for
years (Del Toral et al., 2013). Particulate lead can also be released as part of normal (ongoing)
corrosion processes in the system and is common when pipe scales contain substantial
amounts of iron, manganese and other coatings, or when corrosion of brass or solder is
galvanically driven.
Recommendations for monitoring programs can be found in Kirmeyer et al. (2000, 2002, 2004);
USEPA (2003, 2007d); and MOE (2009).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 73
-------
Chapter 6: Impacts of Source Water and Treatment Changes on Lead and Copper
in Drinking Water
Research over the last several years has shed new light on the impacts of source water and
treatment changes on lead and copper corrosion control. In particular, for systems with lead
service lines, research has shown that lead release is dependent upon many water quality
parameters (WQPs), and that treatment change once thought to be independent of corrosion
control can have a significant impact on lead release.
Section 6.1 reviews the Lead and Copper Rule (LCR) requirements for maintaining optimal
corrosion control treatment (OCCT) and explains when a system is required under the LCR to
notify their primacy agency and obtain approval prior to a source or treatment change. Section
6.2 provides technical information on the effects of source water changes and Section 6.3
follows with technical information about the effects of treatment changes on lead and copper
levels in drinking water.
6.1 Review of LCR Requirements Related to a Change in Source or Treatment
All systems optimizing corrosion control must continue to operate and maintain the treatment,
including maintaining WQPs at or above minimum values or within ranges established by the
primacy agency (§141.81(b) and §141.82(g)). Prior to the addition of a new source or any long-
term change in water treatment, water systems are required to notify the primacy agency in
writing of the change or addition. The primacy agency must review and approve the addition of
a new source or long term change in treatment before it is implemented by the water system.
Switching from purchased water to a new source is an example of source change (USEPA,
2015b). Examples of long-term treatment changes are provided in the LCR and discussed later
in this section. The systems that are subject to this requirement are systems that are either (1)
deemed to have optimized corrosion control pursuant to §141.81(b)(3); (2) subject to reduced
monitoring under §141.86(d)(4), or (3) subject to a monitoring waiver under §141.86(g).
(§141.90(a)(3)).
As described in a November 3, 2015, memorandum from Dr. Peter Grevatt, Director of the
Environmental Protection Agency (EPA) Office of Ground Water and Drinking Water (USEPA,
2015b):
1) The LCR requires that any large system (i.e., those serving > 50,000 people) that has met
OCCT requirements through the installation of corrosion control treatment to continue
operating and maintaining the treatment and to continue meeting the WQPs
established by the primacy agency (§141.81(b) and §141.82(g)).
2) Systems deemed to have OCCT without the installation of corrosion control treatment
are required to notify the primacy agency in writing of any upcoming changes in
treatment or source and request that the primacy agency modify its determination of
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 74
-------
the OCCT and WQPs applicable to the system. The primacy agency must then review
and approve the change and designate OCCT and WQPs prior to its implementation by
the system (§141.81(b)(3)).
3) Systems subject to reduced monitoring under §141.86(d)(4) or monitoring waivers
under §141.86(g) must notify the primacy agency of any upcoming changes in treatment
or source and the primacy agency must subsequently review or approve it
(§141.90(a)(3)).
EPA recommends that systems that are not subject to a notification requirement also notify the
primacy agency prior to the addition of a new source or treatment and request the primacy
agency to modify its determination of the optimal corrosion control and WQPs applicable to the
system (USEPA, 2015b).
Examples of long-term treatment changes include the addition of a new process or modification
of an existing treatment process ((§141.90(a)(3)). Examples of modifications include switching
secondary disinfectants, switching coagulants (e.g., alum to ferric chloride), and switching
corrosion inhibitor products (e.g., orthophosphate to blended phosphate). Long-term changes
can include dose changes to existing chemicals if the system is planning long-term changes to
its finished water pH or residual inhibitor concentration. Long-term treatment changes would
not include chemical dose fluctuations associated with daily raw water quality changes
((§141.90(a)(3)).
Due to the unique characteristics of each system (e.g., source water, existing treatment
processes, distribution system materials) it is critical that public water systems, in conjunction
with their primacy agencies and, if necessary, outside technical consultants, evaluate and
address potential impacts resulting from treatment and/or source water changes prior to
making the change. The evaluation may include a system-wide assessment of source water or
treatment modifications to identify existing or anticipated water quality, treatment or
operational issues that may interfere with or limit the effectiveness of corrosion control
treatment (CCT) optimization or re-optimization. In addition, systems should conduct ongoing
monitoring to ensure compliance with OCCT prior to, during, and after a source or treatment
change (USEPA 2015b).
6.2 Impacts of Source Water Changes
Changes in source water can have a significant impact on water quality, corrosion control
treatment effectiveness, and lead and copper release. Examples of source changes include:
• Switching from a purchased treated water source to an untreated water source that
requires treatment;
• Switching from a purchased treated water source to a different treated source;
• Changing from a ground to surface water source; and
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 75
-------
• Adding a new source, such as a new ground water or purchased source, in the
distribution system.
Not only can source water changes directly impact corrosion control treatment (e.g., pH,
alkalinity, dissolved inorganic carbon (DIG), and corrosion inhibitor concentration), but they can
also impact the effectiveness of corrosion control treatment through changes in water quality
parameters such as natural organic matter (NOM), metals (e.g., iron and manganese), ions such
as chloride and sulfate, oxidation-reduction potential (ORP), and buffer intensity. See Section
2.3 for information on how water quality can impact the release of lead and copper into
drinking water.
The literature includes examples of how source water changes have impacted lead and copper
release (Boyd et al., 2006; 2008). For example, changes in lead release associated with blending
groundwater, treated surface water, and desalinated seawater sources were determined to be
a function of temperature, alkalinity, pH, chloride and sulfate (Taylor et al., 2005; Tang et al.,
2006). Total copper release was been attributed to changes in temperature, alkalinity, pH,
sulfate and silica (Imran et al., 2006; Xiao et al., 2007). In another study (Zhang et al., 2012),
lead release from leaded solder increased with blending of desalinated seawater in pilot-scale
pipe loops.
Source water changes can impact trace inorganic contaminant release from deposits or scales
in the distribution system (Lytle et al., 2004; Schock et al., 2008; Friedman et al., 2010; Peng et
al., 2012). As discussed in Section 2.3.9, dissolved lead can react with iron and manganese and
form deposits on lead service lines and other pipe materials. Shifts in water chemistry (e.g.,
changes associated with blending disparate sources) can potentially affect release and
remobilization of these contaminants in the distribution system (Hill et al., 2010; McFadden et
al., 2011; Friedman et al., 2016), which can then impact the formation of passivating scales on
lead- and copper-containing materials.
6.3 Impacts of Treatment Changes
Treatment changes that can potentially affect the corrosivity of treated water are identified in
several references (USEPA, 2003; USEPA, 2007b; MOE, 2009; Schendel et al., 2009; Grigg,
2010), and discussed in more detail below.
6.3.1 Corrosion Control Treatment
Any proposed change to a system's CCT can have consequences for water quality in the
distribution system and corrosion control effectiveness. Even small changes to pH/alkalinity/DIC
adjustment processes and inhibitor doses can affect lead and copper levels. If a system
proposes changes to any of these key parameters (e.g., lowers pH, lowers or shuts of corrosion
inhibitor), there is the potential for increases in lead and/or copper in the water.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 76
-------
Changes in the inhibitor chemical used for treatment can also affect lead and copper release.
For example, changing from an orthophosphate chemical to a blended phosphate chemical is
significant because the mechanisms by which the two chemicals control lead release are
different, and the effectiveness of blended phosphates depends on other constituents in the
water (e.g., calcium). Changing to a different manufacturer of blended phosphates can impact
lead and copper release, even if the percentage of orthophosphate in the blend is similar (see
Chapter 3 for more information on blended phosphates). Systems may design for a specific
corrosion control product, but obtain bids for different products with different formulations.
Additional drivers for changing the inhibitor chemical include pricing, finished water quality,
operational changes, and changes at the receiving wastewater treatment plant (Brown et al.,
2013a).
6.3.2 Disinfection
Changing disinfectant from free chlorine to chloramine may destabilize Pb(IV) scales formed
under highly oxidizing conditions (high free chlorine residual). This destabilization may cause
higher lead levels to be measured (Boyd et al., 2008; Boyd et al., 2009). In order to prevent
elevated lead levels, systems can maintain the current conditions where Pb(IV) was the
predominant scale, can adjust the pH/alkalinity/DIC to convert scales to Pb(ll) passivating films
(i.e., pH greater than approximately 9.0 and DIC of 5 to 10 mg/L as C), or use an
orthophosphate inhibitor (optimally at pH in the 7.2- 7.8 range) (Lytle et al., 2009). There may
be a period of time during the conversion from Pb(IV) based to Pb(ll) based scales where lead
levels may increase. A real-world example occurred in the District of Columbia with the DC
Water and Sewer Authority (currently known as DC Water) (Schock and Giani, 2004; USEPA,
2007b), in which conversion from free chlorine to chloramines for disinfection, along with pH
variations in the distribution system and the presence of lead service lines contributed to
elevated lead levels over a sustained period of time.
Additional monitoring can help determine the typical range of ORP values (i.e., the baseline) in
the distribution system prior to disinfectant changes. Special laboratory studies to determine
the composition of the lead scales present in the system (e.g., Pb(ll) or Pb(IV) scales) can be
completed using pipe sections removed from the distribution system (Clement et al., 1998b;
Sandvig et al., 2008). Primacy agencies can identify systems that may switch to chloramines or
another disinfectant in the future by reviewing compliance with the Stage 2 Disinfection By-
products Rule (DBPR).
For systems that use chloramines, nitrification may occur in the distribution system. In a
corrosion control guidance manual developed for the Province of Ontario, a case study was
presented in which nitrification reduced the pH from approximately 8.5 to 7.8, which resulted
in increased lead release. In response, the system raised the finished water pH to 9.2 and
observed reductions in lead levels at some sites (MOE, 2009). Nitrification can also be a
problem for ground water systems that add chlorine and have high levels of ammonia in their
source water.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 77
-------
Important Information about Pb(IV)
Do my lead service lines have Pb(IV) scales?
Pb(IV) (also known as Lead IV or Pb++) can occur on any lead surface. It forms under highly oxidative
conditions. If you have lead service lines with a moderate pH (7 - 8), a consistent free chlorine residual
throughout the system (typically 1-2 mg/L or higher), no corrosion inhibitor, and no lead problems,
you might have predominantly Pb(IV) scales. To help determine if your systems is a candidate for
Pb(IV) scales, you can measure ORP of the water - Eh values of 0.7 volts or higher are indicative of
Pb(IV) scales. You can also evaluate the scale on exhumed lead service lines to find out for sure.
Can I promote formation ofPb(IV) scales to reduce lead levels?
Although some utilities are targeting the development of a Pb(IV) scale in their systems to control lead
release (Brown et al., 2013), questions remain as to how systems and primacy agencies can ensure
that disinfectant residuals required for the formation and maintenance of Pb(IV) scales are maintained
within lead service lines throughout the distribution system and to the customer's taps. This may be a
particular challenge with homes that go unoccupied for an extended period of time. Therefore, EPA
has not included formation of a Pb(IV) scale as a corrosion control treatment technique in this
document at this time.
What happens if I have Pb(IV) scales and I change treatment?
Changing disinfectant from free chlorine to chloramine for disinfection may destabilize Pb(IV) scales.
Systems can use other corrosion control treatments such as pH/alkalinity/DIC adjustment or
phosphate-based corrosion inhibitors, but lead levels may increase as the scale is converting from
Pb(IV) to Pb(ll) based scale.
The type of chlorine used for disinfection may also have an impact on corrosion. Use of gaseous
chlorine lowers the pH of the water resulting in potentially more corrosive water. For systems
with low alkalinity water, this effect can be amplified (Schock, 1999). Sodium hypochlorite, a
base, can increase the pH of the water.
6.3.3 Coagulation
Switching from a sulfate based to a chloride based coagulant may increase the chloride content
of the water, increasing the chloride-to-sulfate mass ratio (CSMR). This may aggravate lead
release from galvanic connections such as lead solder on copper pipes or partial lead line
replacements (Oliphant, 1983; Gregory, 1985; Reiber, 1991; Singley, 1994; Lauer, 2005, Nguyen
et al., 2010; Triantafyllidou and Edwards, 2011; Clark et al, 2013; Wang et al, 2013). See Section
2.3.7 for additional discussion on the impacts of changes in chloride and sulfate on lead release.
Changes in pH to optimize the effectiveness of a new coagulant may impact the distribution
system pH and cause changes in lead and copper release (USEPA, 2007d; Duranceau et al.,
2004). Switching coagulants, or increased use of coagulants to achieve enhanced coagulation
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 78
-------
will also remove additional NOM. Changes in NOM can impact corrosion control in the
distribution system; see Section 2.3.8 for more information.
6.3.4 Water Softening
Changing how softening is practiced at a treatment plant can affect corrosion control. Adding
softening will raise the pH and change alkalinity, helping to control lead and copper release,
whereas discontinuing softening will change these parameters, which may cause metal release
(USEPA, 2007b).
6.3.5 Filtration
Nanofiltration and reverse osmosis remove alkalinity, hardness and other dissolved compounds
but do not remove carbon dioxide, resulting in a lower pH which can cause increases in lead
and copper levels measured at the tap. They also remove NOM which can impact corrosivity of
the water (AwwaRF and DVGW-T, 1996; Mays, 1999; Kirmeyer et al., 2000; Duranceau et al.,
2004; Schippers et al., 2004; USEPA, 2007b).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 79
-------
Chapter?: References
APHA, AWWA, and WEF, 2005. Standard Methods for the Examination of Water and
Wastewater, 21st ed. American Public Health Association. Washington, DC.
Appelo, C.A.J., and Postma, D. 2005. Geochemistry, Groundwater and Pollution. New York, NY.
CRC Press.
ASTM D2688-11. 2005. Standard Test Methods for the Corrosivity of Water in the Absence of
Heat Transfer (Weight Loss Methods). ASTM International.
http://www.astm.org/Standards/D2688.htm.
AWWA. 1993. Initial Monitoring Experiences of Large Water Utilities under EPA's Lead and
Copper Rule. Water Industry Technical Action Fund (WITAF). AWWA. Denver, CO.
AWWA. 1999. Water Quality and Treatment, a Handbook of Community Water Supplies. 5th
edition. Raymond Letterman, Editor. AWWA and McGraw-Hill. Denver, CO.
AWWA. 2001. The Rothberg, Tamburini, and Winsor Blending Application Package 4.0. AWWA
Catalog Number 53042. AWWA. Denver, CO.
AWWA. 2004. Proceedings of Workshop - Getting the Lead Out: Analysis and Treatment of
Elevated Lead Levels in DC's Drinking Water. Water Quality Technology Conference. San
Antonio. AWWA. Denver, CO.
AWWA. 2005. Managing Change and Unintended Consequences: Lead and Copper Rule
Corrosion Control Treatment. AWWA. Denver, CO.
AwwaRF. 1990. Lead Control Strategies. AwwaRF Report #90559. Project #406. AWWA
Research Foundation (now Water Research Foundation) and AWWA. Denver, CO.
AwwaRF and DVGW-Technologiezentrum Wasser. 1996. Internal Corrosion of Water
Distribution Systems. 2nd edition. AwwaRF Order 90508. Project #725. AWWA Research
Foundation (now Water Research Foundation) and AWWA. Denver, CO.
Boyd G.R., Dewis, K.M., Sandvig, A.M., Kirmeyer, G.J., Reiber, S.H., and Korshin, G.V. 2006. What
Effect Does Background Water Chemistry Have on Metals Release and Galvanic
Coupling? Chapter 7 in Effect of Changing Disinfectants on Distribution System Lead and
Copper Release, Parti -Literature Review. AwwaRF Order #91152. Project#3107a.
AWWA Research Foundation. Denver, CO.
Boyd, G.R., Dewis, K.M., Korshin, G.V., Reiber, S.H., Schock, M.R., Sandvig, A.M., and Giani, R.,
2008. Effects of Changing Disinfectants on Lead and Copper Release. J. AWWA,
100(ll):75-87.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 80
-------
Boyd, G.R., McFadden, M.S., Reiber, S.H., Sandvig, A.M., Korshin, G.V., Giani, R., and Frenkel,
A.I. 2009. Effect of Changing Disinfectants on Distribution System Lead and Copper
Release: Part 2 - Final Report. WRF Order #3107. Water Research Foundation. Denver,
CO.
Boyd, G.R., Tuccillo, M.E., Sandvig, A., Pelaez, M., Han, C., and Dionysiou, D.D. 2013.
Nanomaterials: Removal Processes and Beneficial Applications in Treatment. J. AWWA,
105(12): E699-E708.
Britton, A. and Richards, W.N. 1981. Factors Influencing Plumbosolvency in Scotland. J. Inst.
Water Engrs. and Scientists, 35(5):349-364.
Brown, R., McTigue, N., and Cornwell, D.A. 2013a. Strategies for Assessing Optimized Corrosion
Control Treatment of Lead and Copper. J. AWWA, 105(5): 62-75.
Brown, R., McTigue, N., and Cornwell, D.A. 2013b. LSI Flushing and OCCT Case Studies. In
Proceedings of the AWWA Annual Conference. AWWA. Denver, CO.
Brown, M.J., Raymond, J., Homa, D., Kennedy, C., and Sinks, T. 2011. Association Between
Children's Blood Lead Levels, Lead Service Lines, and Water Disinfection, Washington,
DC, 1998-2006. Environ. Res., 111(1): 67-74.
Butler, J.N., and Cogley, D.R. 1998. Ionic Equilibrium Solubility and pH Calculations. John Wiley
and Sons, New York, NY.
Cadmus Group. 2004. Investigation of Potential Environmental Impacts Due to the Use of
Phosphate-Based Corrosion Inhibitors in the District of Columbia. Report Prepared for
EPA Region 3.
Cantor, A.F., Denig-Chakoff, D., Vela, R.R., Oleinik, M.G., Lynch, D.L. 2000. Use of Polyphosphate
in Corrosion Control. J. AWWA, 92(2):95.
Carlson, K.H., Via, S., Bellamy, B., and Carlson, M. 2000. Secondary Effects of Enhanced
Coagulation and Softening. J. AWWA. 92(6): 63-75.
Clark, B., Cartier, C., St. Clair, J., Triantafyllidou, S., Prevost, M., and Edwards, M. 2013. Effect of
Connection Type on Galvanic Corrosion Between Lead and Copper Pipes. J. AWWA, 105:
E576-E577.
Clement, J.A.; Daly, W.J.; Shorney, H.J.; and Capuzzi, A.J. 1998a. An Innovative Approach to
Understanding and Improving Distribution System Water Quality. Proceedings of AWWA
Water Quality Technology Conference, San Diego, CA. AWWA. Denver, CO.
Clement, J., Sandvig, A., Snoeyink, V., Kriven, W., and Sarin, P. 1998b. Analyses and
Interpretation of the Physical, Chemical, and Biological Characteristics of Distribution
System Pipe Scales. Water Quality Technology Conference. AWWA. Denver, CO.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 81
-------
Clement, J. A., and Schock, M.R. 1998. Buffer Intensity: What is It, and Why It's Critical for
Controlling Distribution System Water Quality. AWWA Water Quality Technology
Conference, San Diego, CA. AWWA. Denver, CO.
Copeland, A., and Lytle, D.A. 2014. Measuring the Oxidation-Reduction Potential of Important
Oxidants in Drinking Water. J. AWWA, 106(1): E10-E20.
Cook, J.B. 1992. Achieving Optimum Corrosion Control for Lead in Charleston, S.C.; A Case
Study. Jour. NEWWA, 111(2):168.
Cornwell, D., Brown, R., and McTigue, N. 2015. Controlling Lead and Copper Rule Water Quality
Parameters./ AWWA, 107(2): E86-E96.
Del Toral, M.A., Porter, A., and Schock, M.R. 2013. Detection and Evaluation of Elevated Lead
Release from Service Lines: A Field Study. Environ. Sci. Tech. 47(16): 9300-9307.
DeSantis, M.K., and Schock, M.R. 2014. Ground Truthing the 'Conventional Wisdom' of Lead
Corrosion Control Using Mineralogical Analysis. AWWA Water Quality Technology
Conference. November 19, 2014.
Dietrich A.M., Cuppett J.D., Duncan S.E. 2008. How Much Copper Is Too Much? OpFlow,
34(9):8-30.
Dodrill, D.M., and Edwards, M. 1995. Corrosion Control on the Basis of Utility Experience. J.
AWWA, 87(7):74.
Douglas, I., Guthmann, J., Muylwyk, Q. and Snoeyink, V. 2004. Corrosion Control in the City of
Ottawa-Comparison of Alternatives and Case Study for Lead Reduction in Drinking
Water. In: llth Canadian National Drinking Water Conference and 2nd Policy Forum, W.
Robertson and T. Brooks (eds.). April 3-6, Calgary, AB. Canadian Water and Wastewater
Association. Ottawa, ON.
Duranceau, S.J., Townley, D., and Bell, G.E.C. 2004. Optimizing Corrosion Control in Distribution
Systems. AwwaRF Order #90983. Project #2648. AWWA Research Foundation. Denver,
CO.
Edwards, M., and Dudi, A. 2004. Role of Chlorine and Chloramine in Corrosion of Lead-Bearing
Plumbing Materials. J. AWWA, 96(10):69-81.
Edwards, M., Giani, R., Wujek, J., Chung, C. 2004. Use of Lead Profiles to Determine Source of
Action Level Exceedances from Residential Homes in Washington, DC, Sunday Workshop,
AWWA Water Quality Technology Conference, San Antonio, TX.
Edwards, M., Jacobs, S., and Dodrill, D. 1999. Desktop Guidance for Mitigating Pb and Cu
Corrosion By-Products. J. AWWA, 91(5):66-77.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 82
-------
Edwards, M. and McNeill, L.S. 2002. Effect of Phosphate Inhibitors on Lead Release from Pipes.
J. AWWA, 94(1):79-90.
Edwards, M., Meyer, I.E., Rehring, J., Ferguson, J., Korshin, G., and Perry, S. 1996. Role of
Inorganic Anions, NOM, and Water Treatment Process in Copper Corrosion. AwwaRF
Order #90687. Project #831. AWWA Research Foundation. Denver, CO.
Edwards, M. and Reiber, S.H. 1997. Predicting Pb and Cu Corrosion By-Product Release Using
CORRODE Software. AwwaRF Order #907126. Project #910. AWWA Research
Foundation. Denver, CO.
Estes-Smargiassi, S., and Cantor, A. 2006. Lead Service Line Contributions to Lead Levels at the
Tap. AWWA Water Quality Technology Conference. Denver, CO. November 2006.
Freeze, R.A., and Cherry, J.A. 1979. Groundwater. Prentice Hall, NJ.
Friedman, M., Hill, A., Booth, S., Hallett, M., McNeil, L., McLean, J., Stevens, D., Sorenson, D.,
Hammer, T., Kent, W., De Hann, M., MacArthur, K., and Mitchell, K. 2016. Metals
Accumulation and Release within the Distribution System: Evaluation and Mitigation,
Project #4509. Water Research Foundation. Denver, CO.
Friedman, M.J., Hill, A.S., Reiber, S.H., Valentine, R.L., Larsen, G., Young, A., Korshin, G.V., and
Peng, C.Y. 2010. Assessment of Inorganics Accumulation in Drinking Water System
Scales and Sediments. WRF Project #3118. Water Research Foundation. Denver, CO
Gardels, M.C., and Sorg, T.J. 1989. A Laboratory Study of the Leaching of Lead from Water
Faucets. J. AWWA, 81(7):101-113.
Giani, R., Edwards, M., Chung, C., and Wujek, J. 2004. Lead Profiling Methodologies and Results.
Presented at Getting the Lead Out: Analysis and Treatment of Elevated Lead Levels in
DC's Drinking Water at the AWWA Water Quality Technology Conference. Denver, CO.
Gregory, R. 1985. Galvanic Corrosion of Lead and Copper Pipework: Phase I, Measurement of
Galvanic Corrosion Potential in Selected Waters. Water Research Centre Engineering,
Swindon, England.
Grigg, N.S. 2010. Secondary Impacts of Corrosion Control on Distribution System and Treatment
Plant Equipment. Project # 4029. Water Research Foundation. Denver, CO.
http://www.waterrf.org/PublicReportLibrary/4029.pdf.
Hayes, C. R., Incledion, S., Balch, M. 2008. Experience in Wales (UK) of the Optimization Of
Ortho-Phosphate Dosing for Controlling Lead in Drinking Water. Journal of Water and
Health, 6 (2), 177-185.
Hill, C.P., and Cantor, A.F. 2011. Internal Corrosion Control in Water Distribution Systems.
AWWA Manual M58, First Edition. American Water Works Association. Denver, CO.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 83
-------
Hill, A.S., Friedman, M.J., Reiber, S.H., Korshin, G.V., and Valentine, R.L. 2010. Behavior of Trace
Inorganic Contaminants in Drinking Water Distribution Systems. J. AWWA, 107(7): 107-
118.
Holm, T.R., and Schock, M.R. 1991. Potential Effects of Polyphosphate Products on Lead
Solubility in Plumbing Systems. J. AWWA, 83(7):76-82.
Hu, J., Can, F., Triantafyllidou, S., Nguyen, C.K., and Edwards, M.A. 2012. Copper-Induced Metal
Release from Lead Pipe into Drinking Water. Corrosion, 68(11): 1037-1048.
Imran, S.A., Dietz, J.D., Mutoti, G., Xiao, W., Taylor, J.S., and Desai, V. 2006. Optimizing Source
Water Blends for Corrosion and Residual Control in Distribution Systems. J. AWWA,
98(5): 107-115.
James, C.N., Copeland, R.C., and Lytle, D.A. 2004. Relationships between Oxidation-Reduction
Potential, Oxidant, and pH in Drinking Water. In Proceedings of the AWWA Water
Quality Technology Conference. AWWA. Denver, CO.
Kimbrough, D.E. 2001. Brass Corrosion and the LCR Monitoring Program. J. AWWA, 93(2):81-91.
Kimbrough, D.E. 2007. Brass Corrosion as a Source of Lead and Copper in Traditional and All-
Plastic Distribution Systems. J. AWWA, 9S(8):70-76.
Kimbrough, D.E. 2009. Source Identification of Copper, Lead, Nickel, and Zinc Loading in
Wastewater Reclamation Plant Influents from Corrosion of Brass in Plumbing Fixtures.
Environ. Pollut, 157(4) :1310-6.
Kirmeyer, G.J., Clement, J. and Sandvig, A. 2000. Distribution System Water Quality Changes
Following Implementation of Corrosion Control Strategies. AwwaRF Order #90764.
Project #157. AWWA Research Foundation. Denver, CO.
Kirmeyer, G.J., Friedman, M., Martel, K., Thompson, G., Sandvig, A., Clement, J., and Frey, M.
2002. Guidance Manual for Monitoring Distribution System Water Quality. AwwaRF
Order# 90882. Project #2522. AWWA Research Foundation. Denver, CO.
Kirmeyer, G.J., Murphy, B., Sandvig, A., Korshin, G., Shaha, B., Fabricino, M., and Burlingame, G.
2004. Post-Optimization Lead and Copper Control Monitoring Strategies. AwwaRF Order
#90996F. Project #2679. AWWA Research Foundation. Denver, CO.
Kirmeyer, G.J., Sandvig, A.M., Pierson, G.L., and Neff, C.H. 1994. Development of a Pipe Loop
Protocol for Lead Control. AwwaRF Order# 90650. Project #604. AWWA Research
Foundation. Denver, CO.
Korshin, G.V., Perry, S.A.L., and Ferguson, J.F. 1996. Influence of NOM on Copper Corrosion. J.
AWWA, 88(7): 36-47.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 84
-------
Korshin, G.V., Ferguson, J.F., Lancaster, A.N., and Wu, H. 1999. Corrosion and Metal Release for
Lead-Containing Materials: Influence of NOM, AwwaRF Report No. 90759. Denver, CO:
AWWA Research Foundation.
Korshin, G.V., Ferguson, J.F., and Lancaster. A.N. 2000. Influence of Natural Organic Matter on
the Corrosion of Leaded Brass in Potable Water. Corrosion Science, 42: 53-66.
Korshin, G.V., Ferguson, J.F., and Lancaster, A.N. 2005. Influence of Natural Organic Matter on
the Morphology of Corroding Lead Surfaces and Behavior of Lead-Containing Particles.
Water Research, 39(5): 811-818.
Kvech, S., and Edwards, M. 2001. Role of Aluminosilicate Deposits in Lead and Copper
Corrosion. J. AWWA, 93(11):104-112.
LaRosa-Thompson, J., Scheetz, B.E., Schock, M.R., Lytle, D.A., Delaney, P.J. 1997. Sodium Silicate
Corrosion Inhibitors: Issues of Effectiveness and Mechanism. Presented at AWWA Water
Quality Technology Conference.
Lauer, W.C. 2005. Water Quality in the Distribution System. AWWA. Denver, CO.
Letterman, R.D. 1995. Calcium Carbonate Dissolution Rate in Limestone Contactors, Research
and Development Report, EPA/600/SR-95/068, Risk Reduction Engineering Laboratory,
Cincinnati, OH.
Letterman, R.D. Driscoll, C.T., Haddad, M., and Hsu, H.A. 1986. Limestone Bed Contactors for
Control of Corrosion at Small Water Utilities. EPA 600/S2-86/099.
Letterman, R.D. Haddad, M. and Driscoll, C.T., Jr. 1991. Limestone Contactors: Steady State
Design Relationships. Jour. Envir. Engrg. Div.- ASCE, 117(3):339-358.
Letterman, R.D. and Kathari, S. 1996. A Computer Program for the Design of Limestone
Contactors. Jour. NEWWA, 110(l):42-47.
Lytle, D.A., and Schock, M.R. 1996. Stagnation Time, Composition, pH and Orthophosphate
Effects on Metal Leaching from Brass. EPA/600/R-96/103. National Risk Management
Research Laboratory, Office of Research and Development, USEPA. Cincinnati, OH.
Lytle, D.A., and Schock, M.R. 2005. The Formation of Pb (IV) Oxides in Chlorinated Water. J.
AWWA, 97(11):102.
Lytle, D.A., Schock, M.R., Clement, J.A., and Spencer, C.M. 1998. Using Aeration for Corrosion
Control. J. AWWA, 90(3):74-88.
Lytle, D.A., Schock, M.R., and Scheckel, K. 2009. The Inhibition of Pb (IV) Oxide Formation in
Chlorinated Water by Orthophosphate. Environ. Sci. Tech., 43(17), 6624-6631.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 85
-------
Lytle, D. A., Schock, M. R., Sorg, T. J. 1995. Investigation on Techniques and Control of Building
Lead and Copper Corrosion by Orthophosphate and Silicate, NACE Corrosion/95,
Orlando, FL, 1995; pp 609/1-609/29.
Lytle, D.A., Sorg, T.J., and Frietch, C. 2004. Accumulation of Arsenic in Drinking Water
Distribution Systems. Environ Sci Technol., 38(20): 5365.
Mays, L.W. 1999. Water Distribution Systems Handbook. AWWA. Denver
McFadden, M., Giani, R., Kwan, P., and Reiber, S. 2011. Contributions to Drinking Water Lead
from Galvanized Iron Corrosion Scales. J. AWWA, 103(4):76-89.
McNeill, L.S., and Edwards, M. 2004. Importance of Pb and Cu Particulate Species for Corrosion
Control. J. Environ. Eng., 130(2):136-144.
Miller, S. A. Investigation of Lead Solubility and Orthophosphate Addition in High pH Low DIC
Water. Master of Science, Department of Biomedical, Chemical, and Environmental
Engineering, College of Engineering and Applied Science, University of Cincinnati,
Cincinnati, OH, 2014.
MOE. 2009. Guidance Document for Preparing Corrosion Control Plans for Drinking Water
Systems. Ontario Ministry of Environment.
Montgomery, W.H. 2005. Water Treatment Principles and Design. 2nd Edition. John Wiley and
Sons.
Muylwyk, Q., Gilks, J., Suffoletta, V., and Olesiuk, J. 2009. Lead Occurrence and the Impact of LSL
Replacement in a Well Buffered Groundwater. Water Quality Technology Conference
Proceedings. AWWA. Denver, CO.
MWRA. 2010. Massachusetts Water Resources Authority 90th Percentile Lead Levels in MWRA
System of Fully-Supplied Communities, March 2010.
http://www.mwra.com/watertesting/lead/webgraphs/2010/2010-march-640.ipg.
Nguyen, C., Stone, K., Clark, B., Edwards, M. Gagnon, G., and Knowles, A. 2010. Impact of
Chloride:Sulfate Mass Ratio (CSMR) Changes on Lead Leaching in Potable Water. WRF
Project #4088. Water Research Foundation. Denver, CO.
Nguyen, C.K., Stone, K.R., and Edwards, M.A. 2011. Chloride-to-Sulfate Mass Ratio: Practical
Studies in Galvanic Corrosion of Lead Solder, J. AWWA, 103(1): 81-92.
NSF. 2008. Annex G, NSF/ANSI 61-2008. Weighted Average Lead Content Evaluation Procedure
to a 0.25% Lead Requirement. NSF International. Ann Arbor, Michigan.
http://www.documents.dgs.ca.gov/pd/EPP/BM/Plumbing/AnnexG.pdf. Accessed
February 29, 2016.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 86
-------
NSF. 2010. NSF/ANSI 61-2010. Drinking Water System Components- Health Effects. NSF
International. Ann Arbor, Michigan.
Oliphant, R.J. 1983. Summary Report on the Contamination of Potable Water by Lead from
Soldered Joints. Water Research Center Engineering, Swindon, External Report 125-E.
Parkhurst, D.L., and Appelo, C.A.J. 1999. User's Guide to PHREEQC (Version2)—A Computer
Program for Speciation, Batch-Reaction, One-Dimensional Transport, and Inverse
Geochemical Calculations. Water Resources Investigations Report 99-4259. U.S.
Geological Survey. http://wwwbrr.cr.usgs.gov/projects/GWC coupled/phreeqc.
Peng, C.-Y., Hill, A.S., Friedman, M.J., Valentine, R.L., Larson, G.S., Romero, A.M.Y., Reiber, S.H.,
and Korshin, G.V. 2012. Occurrence of Trace Inorganic Contaminants in Drinking Water
Distribution Systems,/ AWWA 104:E181-E193.
Plummer, L.N., and Busenberg, E. 1982. Solubilities of Calcite Aragonite and Vaterite in
Solutions Between 0 and 90°C, and an Evaluation of the Aqueous Model for the System
CaC03-C02-H20. Geochimica et Cosmochimica Acta (The Journal of The Geochemical
Society and The Meteoritical Society), 46: 1011.
Rego, C.A., and Schock, M.R. 2007. Case Studies in the Integrated Use of Scale Analyses to Solve
Lead Problems. Distribution System Research Symposium, AWWA. Denver, CO.
Reiber, S. 1991. Galvanic Stimulation of Corrosion on Lead-Tin Solder-Sweated Joints. J. AWWA,
83(7): 83-91.
Reiber, S., Poulsom, S., Perry, S.A.L., Edwards, M., Patel, S., and Dodrill, D.M. 1997. A General
Framework for Corrosion Control Based on Utility Experience. AwwaRF Order #90712A.
Project #910. AWWA Research Foundation, Denver, CO.
Rezania, L.W., and Anderl, W.H. 1996. Copper Corrosion and Iron Removal Plants. National
Conference on Integrating Corrosion Control and Other Water Quality Goals, Cambridge,
MA.
Rezania, L.W., and Anderl, W.H. 1997. Corrosion Control for High DIC Groundwater: Phosphate
or Bust. AWWA Annual Conference, Atlanta, GA.
Rodgers, M. 2014. Impact of Corrosion Control on Publicly Owned Treatment Works. In
Proceedings of the Water Quality and Technology Conference. AWWA. Denver, CO.
Safe Drinking Water Act Amendments of 1996. Public Law 104-182. 104th Congress.
https://www.congress.gov/104/plaws/publl82/PLAW-104publl82.pdf.
Sandvig, A.M., Boyd, G., Kirmeyer, G., Edwards, M., Triantafyllidou, S., and Murphy, B. 2007.
Performance and Metal Release of Non-Leaded Brass Meters, Components, and Fittings.
AwwaRF Order # 91174. AWWA Research Foundation. Denver, CO.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 87
-------
Sandvig, A., Kwan, P., Kirmeyer, G., Maynard, B., Mast, D., Trussell, R.R., Trussell, S., Cantor, A.,
and Prescott, A. 2008. Contribution of Service Line and Plumbing Fixtures to Lead and
Copper Rule Compliance Issues. AwwaRF Order # 91229. Project #3018. AWWA Research
Foundation. Denver, CO.
Schendel, D.B., Chowdhury, Z.K., Hill, C.P., Summers, R.S., Towler, E., Balaji, R., Raucher, R.S.,
and Cromwell, J. 2009. Simultaneous Compliance Tool: A Decision Tool to Help Utilities
Develop Simultaneous Compliance Strategies. WRF Order # 91263. Project #3115. Water
Research Foundation. Denver, CO.
Schippers, J.C., Kruithof, J.C., Nederlof, M.M., Hofman, J.A.M.H. and Taylor, J. 2004. Integrated
Membrane Systems. AwwaRF Order #90899. Project #264. AWWA Research Foundation.
Denver, CO.
Schneider, O.D. Parks, J., Edwards, M., Atassi, A., and Kashyap, A. 2011. Comparison of Zinc
Versus Non-zinc Corrosion Control for Lead and Copper. WRF Project #4103. Water
Research Foundation. Denver, CO.
Schneider, O.D., Hughes, D.M., Bukhari, Z., LeChevallier, M., Schwartz, P., Sylvester, P., and Lee,
J.J. 2010. Determining Vulnerability and Occurrence of Residential Backflow. J. AWWA,
102(8):52-63.
Schock, M.R. 1980. Response of Lead Solubility to Dissolved Carbonate in Drinking Water. J.
AWWA, 72(12):695-704.
Schock, M. R. 1981. Erratum—Response of Lead Solubility to Dissolved Carbonate in Drinking
Water. 7. AWWA,73(3):36.
Schock, M.R. 1989. Understanding Corrosion Control Strategies for Lead. J. AWWA, 81(7):88-
101.
Schock, M. 1996. Corrosion Inhibitor Applications in Drinking Water Treatment: Conforming to
the Lead and Copper Rule. Presented at NACE Corrosion 1996 Conference.
Schock, M.R. 1999. Internal Corrosion and Deposition Control. In Water Quality and Treatment,
5th Edition. R. Letterman (Ed.). McGraw-Hill Inc. New York, NY.
Schock, M.R. 2001. Tetravalent Lead: A Hitherto Unrecognized Control of Tap Water Lead
Contamination. AWWA Water Quality Technology Conference. Denver, CO.
Schock, M.R. 2005. Lead Chemistry Basics, Scale Formation, and Corrosion Control Treatment.
Simultaneous Compliance: The Lead/Chloramine Example. April 13, 2005, Virginia
Section AWWA, Richmond, VA.
Schock. M.R. 2007a. Distribution System Considerations for Treatment. Workshop on Inorganic
Contaminant Issues August 22, 2007, Cincinnati, OH.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 88
-------
Schock, M.R. 2007b. New Insights Into Lead Corrosion Control and Treatment Change Impacts
(with Some Considerations Towards Cu). Presented at Emerging Issues in Water
Treatment Ml Section, AWWA. May 15, 2007.
Schock, M.R., Cantor, A.F., Triantafyllidou, S., DeSantis, M.K., Scheckel, K.G. 2014. Importance of
Pipe Deposits to Lead and Copper Rule Compliance. J. AWWA. 106(7): E336-E349.
Schock, M.R., Clement, J.A., Lytle, D.A., Sandvig, A.M., and Harmon, S.M. 1998. Replacing
Polyphosphate with Silicate to Solve Problems with Lead, Copper and Source Water
Iron. AWWA Water Quality Technology Conference, November 1-4, San Diego, CA.
Schock, M. R., DeSantis, M. K., Metz, D. H., Welch, M. M., Hyland, R.N., Nadagouda, M.N. 2008.
Revisiting the pH Effect on the Orthophosphate Control of Plumbosolvency, Proceedings
of the AWWA Annual Conference and Exposition, Atlanta, GA.
Schock, M.R., and Fox, J.C. 2001. Solving Copper Corrosion Problems while Maintaining Lead
Control in a High Alkalinity Water Using Orthophosphate. AWWA Annual Conference,
June 3-7, Washington, DC.
Schock, M.R., and Giani, R. 2004. Oxidant/Disinfectant Chemistry and Impacts on Lead
Corrosion. AWWA Water Quality Technology Conference. Denver, CO.
Schock, M.R., Holldber, J., Lovejoy, T.R., and Lowry, J. 2002. California's First Aeration Plants for
Corrosion Control. J. AWWA, 94(3):88-100.
Schock, M.R., Hyland, R., and Welch, M. 2008. Occurrence of Contaminant Accumulation in
Lead Pipe Scales from Domestic Drinking Water Distribution Systems. Environ. Sci.
Technol., 42(12): 4285-91.
Schock, M. R., and Lemieux, F.G. 2010. Challenges in addressing variability of lead in domestic
plumbing. Water Science & Technology: Water Supply, 10 (5): 792-798.
Schock, M.R., and Lytle, D.A. 2011. Chapter 20: Internal Corrosion and Deposition Control. In
Water Quality and Treatment. 6th Edition. AWWA and McGraw-Hill, Inc.
Schock, M.R., Lytle, D.A., Sandvig, A.M., Clement, J, and Harmon, S.M. 2005. Replacing
Polyphosphate with Silicate To Solve Lead, Copper, and Source Water Iron Problems. J.
AWWA, 97(11): 84-93.
Schock, M.R, and Rego, C. 2005. Lead and Copper Corrosion Control Theory Update. New
England Water Works Association Conference Spring Exposition and Conference.
Schock, M.R., Sandvig, A.M., Lemieux, F.G., Desantis, M.K. 2012. Diagnostic Sampling to Reveal
Hidden Lead and Copper Health Risks. 15th Canadian National Conference and 6th Policy
Forum on Drinking Water, Kelowna, BC, October 21-24.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 89
-------
Schock, M.R., Scheckel, K.G., DeSantis, M., and Gerke, T.L. 2005. Mode of Occurrence,
Treatment and Monitoring Significance of Tetravalent Lead. AWWA Water Quality
Technology Conference. Denver, CO.
Schock, M.R., Triantafyllidou, S., and DeSantis, M.K. 2014. Peak Lead Levels and Diagnostics in
Lead Service Lines Dominated by Pb02. In Proceedings of the AWWA Annual
Conference. AWWA. Denver, CO.
Schock, M.R.; Wagner, I.; Oliphant, R. 1996. The Corrosion and Solubility of Lead in Drinking
Water. In Internal Corrosion of Water Distribution Systems; 2nd edition. AwwaRF Order
#90508. Project #725. AWWA Research Foundation/DVGW Forschungsstelle. Denver,
CO. 131-230.
Sheiham, I., and Jackson, P.J. 1981. The Scientific Basis for Control of Lead in Drinking Water by
Water Treatment. J. Inst Water Engrs. and Scientists, 35(6):491.
Singley, J.E. 1994. Electrochemical Nature of Lead Contamination. J. AWWA, 86(7): 91-96.
Smith, S.E., Colbourne, J.S., Holt, D.M., Lloyd, B.J. and Bisset, A. 1997. An Examination of the
Nature and Occurrence of Deposits in a Distribution System and their Effect on Water
Quality. AWWA Water Quality Technology Conference, November 17-21. Denver, CO.
Snoeyink, V., and Jenkins, D. 1980. Water Chemistry. John Wiley and Sons. New York, NY.
Snoeyink, V.L., Schock, M.R., Sarin, P., Wang, L., Chen, A.S., Harmon, C, and S.M. 2003.
Aluminum-Containing Scales in Water Distribution Systems: Prevalence and
Composition. Journal of Water Supply: Research and Technology —Aqua, 52 (7): 455-
474.
Spencer, C.M. 1998. Aeration and Limestone Contact for Radon Removal and Corrosion Control.
Jour. NEWWA, 112(l):60-69.
Spencer, C.M., and Brown, W.E. 1997. pH Monitoring to Determine Aeration Effectiveness for
Carbon Dioxide and Radon Removal. In Proceedings of AWWA Water Quality Technology
Conference, November 9-13, Denver, CO.
Stone, K., Nguyen, C. and Edwards, M. 2009. Practical Identification and Resolution of Lead
Corrosion Issues Due to Elevated Chloride to Sulfate Mass Ratio. AWWA Annual
Conference, June 2009, San Diego, CA.
Stumm, W., and Morgan, J.J. 1981. Aquatic Chemistry: An Introduction Emphasizing Chemical
Equilibria in Natural Waters. 2nd Edition. John Wiley and Sons, New York.
Swertfeger, J., Hartman, D.J., Shrive, C., Metz, D., and DeMarco, J. 2006. Water Quality Effects
of Partial Lead Replacement. In Proceedings of the AWWA Annual Conference. AWWA.
Denver, CO.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 90
-------
Tang, Z., Hong, S., Xiao, W., and Taylor, J. 2006. Impacts of Blending Ground, Surface and Saline
Waters on Lead Release in Drinking Water Distribution Systems. Water Research, 40:
943-950.
Taylor, J.S., Dietz, J.D., Randall, A.A., Hong, S.K., Norris, C.D., Mulford, L.A., Arevalo, J.M., Imran,
S., Le Puil, M., Liu, S., Mutoti, I., Tang, J., Xiao, W., Cullen, C., Heaviside, R., Mehta, A.,
Patel, M., Vasquez, F., and Webb, D. 2005. Effects of Blending on Distribution System
Water Quality. AwwaRF Order #91065F. Project #2702. AWWA Research Foundation.
Denver, CO.
Taylor, J.S., Dietz, J.D., Randall, A.A., Norris, CD., Alsheri, A., Arevalo, J., Guan, X., Lintereur, P.,
MacNevin, D., Stone, E., Vaidya, R., Zhao, B., Glatthorn, S. and Shekhar, A. 2008. Control
of Distribution System Water Quality Using Inhibitors. AwwaRF Order #91241F. Project
#2702. AWWA Research Foundation. Denver, CO.
Triantafyllidou, S., and Edwards, M. 2010. Contribution of Galvanic Corrosion to Lead in Water
after Partial Lead Service Line Replacements. Order #4088b. Project #4088. Water
Research Foundation. Denver, CO.
Triantafyllidou, S., and Edwards, M. 2011. Galvanic Corrosion after Simulated Small-Scale Partial
Lead Service Line Replacements./ AWWA, 103(9): 85-98.
Uchida, M., and Okuwaki, A. 1999. Dissolution Behavior of Lead Plates in Aqueous Nitrate
Solutions. Corros. Sci., 41(10): 1977-1986.
USEPA. 1982. EPA Method 150.1, pH (Electrometric).
https://www.nemi.gov/methods/method summary/4685/
USEPA. 1987. Amendments to the Safe Drinking Water Act. 52 FR 20674, June 2, 1987.
USEPA. 1991a. Lead and Copper Rule. Drinking Water Regulations; Maximum Contaminant
Level Goals and National Primary Drinking Water Regulations for Lead and Copper; Final
Rule. Federal Register, 56(110): 26505. June 7,1991.
USEPA. 1991b. Lead and Copper Rule. Drinking Water Regulations; Maximum Contaminant
Level Goals and National Primary Drinking Water Regulations for Lead and Copper; Final
Rule. Technical Correction. Federal Register 56(135): 32112. July 15, 1991.
USEPA. 1992a. Lead and Copper Rule Guidance Manual, Vol. II: Corrosion Control Treatment.
Report No. EPA/811-B-92/002. US Environmental Protection Agency. Washington, DC.
http://www.epa.gov/sites/production/files/2015-09/documents/lcr-guidance-manual-
vol-ii-cct.pdf
USEPA. 1992b. Lead and Copper Rule. Drinking Water Regulations; Maximum Contaminant
Level Goals and National Primary Drinking Water Regulations for Lead and Copper; Final
Rule. Technical Correction. Federal Register, 57(125): 28785. June 29, 1992.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 91
-------
USEPA. 1994. Lead and Copper Rule. Drinking Water Regulations; Maximum Contaminant Level
Goals and National Primary Drinking Water Regulations for Lead and Copper; Final Rule.
Technical Correction. Federal Register, 59(125): 33860. June 30, 1994.
USEPA. 1997. Interpretation of New Drinking Water Requirements Relating to Lead Free
Plumbing Fittings and Fixtures. Federal Register 62(63): 44684. Aug. 22, 1997.
USEPA. 2000. National Primary Drinking Water Regulations for Lead and Copper. Federal
Register, 65(8): 1950-2015. January 12, 2000. http://www.gpo.gov/fdsys/pkg/FR-2000-
01-12/pdf/00-3.pdf.
USEPA. 2001. How to Determine Compliance with Optimal Water Quality Parameters as Revised
by the Lead and Copper Rule Minor Revisions. United States Environmental Protection
Agency. Office of Water 4606. EPA 815-R-99-019. February 2001.
http://water.epa.gov/lawsregs/rulesregs/sdwa/lcr/compliancehelp.cfm.
USEPA. 2003. Final Revised Guidance Manual for Selecting Lead and Copper Control Strategies.
Report No. EPA-816-R-03-001. US Environmental Protection Agency, Washington, DC.
http://www.epa.gov/dwreginfo/lead-and-copper-rule-compliance-help-primacv-
agencies.
USEPA. 2004a. USEPA Lead and Copper Rule Workshop 2: Monitoring Protocols Summary. May
12-13, 2004.
https://owpubauthor.epa.gov/lawsregs/rulesregs/sdwa/lcr/upload/2004_06_25_lcrmr_
pdfs_summary_lcmr_review_monitoring_workshop_summary_05-04.pdf
USEPA. 2004b. USEPA Lead and Copper Rule Workshop 1: Simultaneous Compliance Summary,
May 11-12, 2004. Accessed at
https://owpubauthor.epa.gov/lawsregs/rulesregs/sdwa/lcr/upload/2004 06 25 Icrmr
pdfs summary Icmr review simultaneous compliance workshop 05-04.pdf.
USEPA. 2004c. Lead and Copper Rule. Drinking Water Regulations; Maximum Contaminant
Level Goals and National Primary Drinking Water Regulations for Lead and Copper; Final
Rule. Federal Register, 69(124): 38850. June 29, 2004.
USEPA. 2004d. USEPA Local Limits Development Guidance. Office of Wastewater Management
1203. EPA 833-R-04-002A. July 2004.
https://www3.epa.gov/npdes/pubs/final local limits guidance.pdf.
USEPA. 2004e. Lead and Copper Rule - Clarification of Requirement for Collecting Samples and
Calculating Compliance. Office of Water (4606). November 23, 2004.
http://www.epa.gov/dwreginfo/lead-and-copper-rule-clarification-requirements-
collecting-samples-and-calculating.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 92
-------
USEPA. 2005. Drinking Water Lead Reduction Plan - EPA Activities to Improve Implementation
of the Lead and Copper Rule. March 2005. EPA 810-F-05-001.
http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P10051WL.txt.
USEPA. 2005. USEPA Lead and Copper Rule Workshop: Lead in Plumbing, Fittings, and Fixtures.
July 26-27, 2005.
https://owpubauthor.epa.gov/lawsregs/rulesregs/sdwa/lcr/upload/2005 08 30 Icrmr
pdfs summary Icmr review school plumbing.pdf.
USEPA. 2006a. Inorganic Contaminant Accumulation in Potable Water Distribution Systems.
Office of Water (4601M). December 2006.
USEPA. 2006b. Point-of-Use or Point-of-Entry Treatment Options for Small Drinking Water
Systems, EPA 815-R-06-10. April 2006. http://www.epa.gov/sites/production/files/2015-
09/documents/guide smallsystems pou-poe june6-2006.pdf.
USEPA. 2006c. Management of Aerators during Collection of Tap Samples to Comply with the
Lead and Copper Rule. Office of Water (4606). October 20, 2006.
http://nepis.epa.gov/Exe/ZyPDF.cgi/P100NEFU.PDF?Dockey=P100NEFU.PDF.
USEPA. 2006d. 37s for Reducing Lead in Drinking Water in Schools (Revised). EPA 816-B-05-008.
Office of Water. October 2006. http://www.epa.gov/sites/production/files/2015-
09/documents/toolkit leadschools guide 3ts leadschools.pdf.
USEPA. 2007a. National Primary Drinking Water Regulations for Lead and Copper: Short-Term
Regulatory Revisions and Clarifications. Federal Register, 72 (195) :57782-57820.
October 10, 2007. https://www.federalregister.gov/articles/2007/10/10/E7-
19432/national-primary-drinking-water-regulations-for-lead-and-copper-short-term-
regulatory-revisions-and.
USEPA. 2007b. Simultaneous Compliance Guidance Manual for Long Term 2 and Stage 2 DBF
Rules. Office of Water (4601). EPA 815-R-07-017. March 2007.
http://nepis.epa.gov/Exe/ZyPDF.cgi/60000E2Q.PDF?Dockey=60000E2Q.PDF.
USEPA. 2007c. Elevated Lead in D.C. Drinking Water - A Study of Potential Causative Events,
Final Summary Report. Office of Water (4607M). EPA 815-R-07-021. August 2007.
http://nepis.epa.gov/Exe/ZyPDF.cgi/P1007ZEI. PDF?Dockey=P1007ZEI. PDF.
USEPA. 2007d. Lead and Copper Rule 2007 Short Term Revisions and Clarifications State
Implementation Guidance. Office of Water (4606M). EPA 816-D-07-003. December
2007. http://nepis.epa.gov/Exe/ZyNET.exe/P100A2A8.TXT
http://nepis.epa.gov/Exe/ZyPDF.cgi/P100A2A8.PDF?Dockey=P100A2A8.PDF.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 93
-------
USEPA. 2008a. Implementing the Lead Public Education Provisions of the Lead and Copper Rule:
A Guide for Community Water Systems. Office of Water (4606M). EPA 816-R-08-007.
June 2008. http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockev=60001l4N.txt.
USEPA. 2008b. Implementing the Lead Public Education Provisions of the Lead and Copper Rule:
A Guide for Non-Transient Non-Community Water Systems. Office of Water (4606M).
EPA 816-R-08-008. June 2008.
http://nepis.epa.gov/Exe/ZvPDF.cgi?Dockev=60001l2F.txt.
USEPA. 2008c. Lead and Copper Rule: A Quick Reference Guide. Office of Water (4606). EPA
816-F-08-018. http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=60001N8P.txt .
USEPA. 2010a. The Secondary Maximum Contaminant Level (SMCL) for aluminum indicates an
acceptable range between 0.05 mg/l - 0.20mg/l. Why did EPA develop a range for this
secondary contaminant, rather than a specific acceptable level? Frequent Questions:
Consumer Concerns. Contaminant-Specific Concerns. Modified September 2010.
https://safewater.zendesk.com/hc/en-us/articles/211406148-The-Secondarv-
Maximum-Contaminant-Level-SMCL-for-aluminum-indicates-an-acceptable-range-
between-0-05-mg-l-0-20mg-l-Whv-did-EPA-develop-a-range-for-this-secondarv-
contaminant-rather-than-a-specific-acceptable-level-.
USEPA. 2010b. Nutrient Control Design Manual. Office of Research and Development. EPA
600/R-10/100. August 2010.
http://nepis.epa.gov/Exe/ZyPDF.cgi/P1008KTD. PDF?Dockey=P1008KTD. PDF.
USEPA. 2010c. Lead and Copper Rule Monitoring and Reporting Guidance for Public Water
Systems. Office of Water (4606M). EPA 816-R-10-004. March 2010.
http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockev=P100DP2P.txt.
USEPA. 2013a. Drinking Water Best Management Practices For Schools and Child Care Facilities
With Their Own Drinking Water Source. EPA 816-B-13-001. April 2013.
http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockev=P100GOT8.txt.
USEPA. 2013b. Summary of the Reduction of Lead in Drinking Water Act and Frequently Asked
Questions. Office of Water (4707M) EPA 815-S-13-003. December 19, 2013.
http://nepis.epa.gov/Exe/ZyPDF.cgi/P100M5DB.PDF?Dockev=P100M5DB.PDF.
USEPA. 2015a. How to Identify Lead-Free Certification Marks for Drinking Water System &
Plumbing Materials. EPA/600/F-13/153c. Revised March 2015.
http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100LVYK.txt.
USEPA. 2015b. Memorandum from Peter C. Grevatt, Director, Office of Ground Water and
Drinking Water, to EPA Regional Water Division Directors, Regions I-X. Lead and Copper
Rule Requirements for Optimal Corrosion Control Treatment for Large Drinking Water
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 94
-------
Systems. November 3, 2015. http://www.epa.gov/sites/production/files/2015-
11/documents/occt req memo signed pg 2015-11-03-155158 508.pdf.
Vaidya, R.D. 2010. The Impact of Corrosion Inhibitors on Iron, Copper, and Lead Surface Scales
in Drinking Water. In Proceedings oftheAWWA Annual Conference. AWWA. Denver, CO.
Wang, Y., Mehta, V., Welter, G.J., and Giammar, D.E. 2013. Effect of Connection Methods on
Lead Release from Galvanic Corrosion. J. AWWA, 105(7): E337-E351.
Wasserstrom, L.W., Schock, M.R., and Miller, S.A. 2015. Practical Implications from Observed
Lead Pipe Scale Mineralogy in a Blended Phosphate Treated System. AWWA Annual
Conference and Exposition, June 9, 2015.
Wilczak, A.J., Hokanson, D.R., Rhodes Trussel, R., Boozarpour, M., and Degraca, A. 2010. Water
Conditioning For LCR Compliance and Control Of Metals Release In San Francisco's
Water System. J. AWWA, 102(3):52-64.
Xiao, W., Hong, S., Tang, Z., and Taylor, J.S. 2007. Effects of Blending on Total Copper Release in
Distribution Systems, J. AWWA, 99(1): 78-88.
Zhang, Y., Tseng, T.J., Andrews-Tate, C, Cheng, R.C., and Wattier, K.L. 2012. Pilot-Scale
Evaluation of Blending Desalinated Seawater into a Distribution System, J. AWWA, 104:
E416-E429.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems 95
-------
Appendix A - Glossary
Term
90th Percentile
Action Level (AL)
Action Level
Exceedance
Aeration
Alkalinity
Aluminum Carryover
Analogous Systems
Anion
Anode
Anodic inhibitor
Buffer Index
Buffer Intensity
Cation
Definition
The concentration of lead or copper in tap water that is exceeded by 10 percent
of the sites sampled during a monitoring period. For systems collecting five
samples, the 90th percentile is the average of the fourth and fifth highest lead or
copper result. For systems that are allowed by their primacy agencies to collect
fewer than five samples, this value is the highest lead or copper result. The 90th
percentile level is compared to the lead or copper action level (AL) to determine
whether an AL has been exceeded.
The concentration of lead or copper in tap water which determines whether a
system may be required to install corrosion control treatment (CCT), collect
water quality parameter (WQP) samples, collect lead and copper source water
samples, replace lead service lines (LSLs), and/or deliver public education
materials to consumers about lead. The action level for lead is 0.015 mg/L. The
action level for copper is 1.3 mg/L.
Occurs when the 90th percentile lead or copper sample result is above its
respective AL.
A non-chemical method used for oxidation or adjusting pH where air is
introduced into the water. This removes carbon dioxide, which results in an
increase in pH.
The capacity of water to neutralize acid. It is the sum of carbonate (HCO3~),
bicarbonate (HCO3~), and hydroxide (OH") anions in the water.
This may occur when a system uses aluminum-containing compounds in their
treatment and the aluminum passes through the treatment plant processes into
the distribution system. It may affect hydraulic capacity or tie up
orthophosphate needed for effective corrosion control treatment.
Water systems with similar water quality, treatment, and distribution systems.
A negative ion; an atom or group of atoms that has gained one or more
electrons.
The component of an electrochemical cell where oxidation occurs and electrons
are generated.
A substance which can be used to reduce oxidation reactions at the anode.
The ability of a water to provide buffering against a pH increase or decrease
caused by a corrosion process or water treatment chemical addition.
Also called buffer capacity, this is a measure of the resistance of a water to
changes in pH, either up or down. It is related to alkalinity (sum of bicarbonate,
carbonate, and hydroxyl ions) but varies with pH.
A positive ion; an atom or group of atoms that has lost one or more electrons.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
A-l
-------
Term
Chloride-to-sulfate
mass ratio (CSMR)
Community Water
System (CWS)
Corrosion
Corrosion Control
Treatment (CCT)
Corrosion Rate
Corrosivity
Coupon Study
Cu
Demonstration Study
Desktop Study
Dissolved Inorganic
Carbon (DIG)
Eh Value
Electromotive Force
(EMF)
Entry Point
Finished Water
Flushed Sample
Galvanic Corrosion
Definition
The relative ratio of chloride ions (Cl~) to sulfate ions (SO42~) in the water.
A public water system (PWS) that serves at least 15 service connections used by
year-round residents or regularly serves at least 25 year-round residents.
The physicochemical interaction between a metal and its environment which
results in changes in the properties of the metal.
A treatment designed to reduce the corrosivity of water toward metal plumbing
materials, particularly lead and/or copper.
The amount of substance transferred per unit time at a specified surface during
corrosion.
The ability of a substance to break down (corrode) materials.
Study that uses metal pieces (i.e., coupons) of lead, copper, iron, or steel to
help determine how specific water treatments may help prevent release of
metals from these materials.
The chemical symbol for copper.
A study to evaluate alternative treatment approaches for reducing lead and/or
copper levels which includes development and implementation of testing
protocols. Demonstration testing can incorporate pipe loops, coupon tests,
scale analysis, or partial system testing.
A study to determine appropriate corrosion control treatment for reducing lead
and/or copper levels which includes evaluations of literature, historical data and
information, theory, and similar system information.
An estimate of the amount of total carbonates in the form of carbon dioxide gas
(CO2or H2CO3), bicarbonate ion (HCO3~), and carbonate ion (CO32~).
The electrical potential as measured by an oxidation-reduction potential (ORP)
probe. The higher the Eh value the more oxidizing the conditions.
Energy supplied by a source divided by the electric charge transported through
the source. For a galvanic cell it is equal to the electric potential difference for
zero current through the cell.
Refers to points of entry into the drinking water distribution system from which
samples will be representative of each source after treatment.
Water that has been treated and is ready to be delivered to customers.
A water sample collected after the water has been allowed to run for a
specified period of time.
Occurs when two different types of metals or alloys physically contact each
other. One of the metals serves as the anode, with its corrosion rate
accelerated, while the other serves as the cathode, with its corrosion rate
reduced.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
A-2
-------
Term
Hardness
Ionic Strength
Langelier Saturation
Index (LSI)
Large Water System
LCR
Lead-free
Lead Service Line (LSL)
Limestone Contactor
Maximum
Contaminant Level
Goal (MCLG)
Medium Water System
Microbial and
Disinfection
Byproducts Rules
(MDBPR)
Natural Organic
Matter (NOM)
Nitrification
Non-transient, Non-
Community Water
System (NTNCWS)
Definition
A measure of the amount of calcium and magnesium in the water. Hardness is
reported "as CaCO3", that is as calcium carbonate. Hardness must be taken into
consideration when corrosion control is selected and implemented because too
much hardness can cause unintended side effects such as increased scaling,
either within the pump station/treatment plant or out in the service area.
A measure of the concentration of ions in solution.
The comparison between the measured pH of a water with the pH the water
would have at saturation with CaCO3. The LSI should only be used to predict
scaling potential as an adverse secondary impact of pH or alkalinity adjustment
and has no value as a corrosivity indicator for lead and copper.
System serving more than 50,000 people.
An acronym used to describe the Lead and Copper Rule, which was originally
published on June 7, 1991 and also includes subsequent revisions to the rule.
The Reduction of Lead in Drinking Water Act was enacted on January 4, 2011 to
amend the Safe Drinking Water Act (SDWA) to redefine the definition of "lead-
free". The bill specifies a maximum weighted average of 0.25 percent for
wetted surfaces of pipes, fittings, and fixtures and retains the maximum lead
content of 0.2 percent for solder and flux. This revised definition became
effective on January 4, 2014.
A service line made of lead which connects the water main to the building inlet
and any lead pigtail, gooseneck or other fitting which is connected to such lead
line (§141.2).
A method for increasing pH, alkalinity, and calcium level by having water flow
through a bed of crushed limestone.
The level of a contaminant in drinking water below which there is no known or
expected risk to health. It is set at zero for lead and 1.3 mg/Lfor copper.
A water system that serves 3,301 to 50,000 people.
A series of rules from the Environmental Protection Agency (EPA) designed to
help provide the protection of drinking water supplies from microbial
contamination while minimizing health risks from the formation of disinfection
byproducts.
Organic material derived from plants and animals in the environment.
Nitrification occurs when nitrifying bacteria convert ammonia (NH3) into nitrite
(NO2~) and nitrate (NO3~), which may lower the pH and alkalinity of the water,
potentially accelerating brass corrosion and causing problems with lead release.
A public water system that is not a community water system and regularly
serves at least 25 of the same persons during a minimum of 6 months of each
year.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
A-3
-------
Term
Optimal Corrosion
Control Treatment
(OCCT)
Optimal Water Quality
Parameters (OWQPs)
Orthophosphate
Oxidant
Oxidation-Reduction
Potential (ORP)
Partial System Testing
Passivating Scale
Pb
PH
Phosphate Inhibitors
Pipe Loop Testing
Point-of-Use (POU)
Treatment Unit
Polyphosphates
Definition
The corrosion control treatment that minimizes the lead and copper
concentrations at users' taps while ensuring that the treatment does not cause
the water system to violate any National Primary Drinking Water Regulations
(NPDWRs).
Specific ranges or minimums that are determined by the primacy agency for
each relevant WQP. OWQPs represent the conditions under which systems
must operate their corrosion control treatment to most effectively minimize the
lead and copper concentrations at their users' taps while not violating any
NPDWR.
The active agent for phosphate-based inhibitor chemicals that, when added to
the water, can combine with lead and copper to form several different
compounds that have a strong tendency to stay in solid form (i.e., not dissolve
into the water).
A chemical compound that readily transfers oxygen atoms, or a substance that
gains electrons in a redox chemical reaction.
Also termed redox potential. An electrical measurement that describes the
ability of a water to oxidize or reduce substances. It affects how the water
interacts with solid substances, such as pipe materials in a distribution system,
and it affects the thermodynamic stability of minerals.
A type of demonstration study in which CCT is evaluated full-scale by applying
the treatment to a hydraulically isolated portion of the distribution system.
A protective layer comprised of insoluble forms of metals that forms on the
pipe surface and helps to prevent the release of lead or copper to the water.
The chemical symbol for lead.
The pH of a water is a measure of its acidity, otherwise known as hydrogen ion
concentration (H+or H3O+).
Chemicals used to control lead by forming passivating phosphate-based
compounds that help prevent (or inhibit) lead and copper from going into
solution. Orthophosphate is the active agent for phosphate-based inhibition.
Pipe loops consist of pipes or pipe sections made of a variety of materials,
including lead pipe (new or excavated); copper pipe; copper pipe with lead
soldered joints, or brass components (faucets or meters). Pipe loop testing is
used to evaluate the ability of corrosion control treatments to reduce metals
levels in the water.
Treatment unit applied to a single tap to reduce contaminants in the drinking
water at the one faucet.
Polymers comprised of linked units of Orthophosphate that are used to
sequester (or bind) iron, manganese, and other constituents in the water to
keep them in solution.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
A-4
-------
Term
Definition
Pourbaix Diagram
Also known as a potential-pH diagram, designed to predict what aqueous
species or corrosion by-product solid phases are thermodynamically stable
under different conditions of electrochemical potential and pH.
Premise Plumbing
Premise plumbing includes that portion of the potable water distribution
system associated with schools, hospitals, public and private housing, and other
buildings.
Profile Testing
A type of demonstration study in which several sequential stagnation samples
are collected at the tap and analyzed for lead and/or copper. This protocol for
sampling can be used to evaluate lead and/or copper release from specific
portions of the service line and premise piping system in a residence, and can
help identify both the sources of lead and copper and the impact of
replacement of plumbing materials on lead and copper.
Public Water System
(PWS)
A system that provides piped water for human consumption, which has at least
15 service connections or regularly serves an average of at least 25 individuals
daily for at least 60 days of the year. It includes: 1) the collection, treatment,
storage, and distribution facilities operated and used by the system, and 2) any
collection or pretreatment storage facilities not under the control of the
system, but which it primarily uses.
Redox (Lead) Chart
A chart which shows lead speciation as a function of pH and the oxidizing or
reducing environment and can be used to identify the potential for a change in
ORP to influence lead or copper levels.
Secondary Standards
Federally non-enforceable guidelines regulating contaminants that may cause
cosmetic, aesthetic effects (such as taste, odor, or color), or technical effects
(corrosion, staining, scaling, and sedimentation) in drinking water. Iron (Fe) and
manganese (Mn) are two contaminants with secondary standards (of 0.3 mg/L
and 0.05 mg/L, respectively) based on their aesthetic and technical effects.
Sequestering Agents
Chemicals used to absorb metals such as iron and manganese that may
interfere with treatment and/or cause customer complaints such as staining or
taste problems. Examples include polyphosphates, sodium
hexametaphosphate, and silicates.
Silicate Inhibitors
A mixture of soda ash and silicon dioxide that can form metal silicate
compounds that serve as anodic inhibitors (i.e., they inhibit the oxidation and
dissolution of the metal). They can passivate the surface of lead and copper
based materials and help to reduce lead and copper levels. They can also
sequester iron and manganese.
Small Water System
A water system that serves 25 to 3,300 people.
Solder
A metallic compound used to seal joints in plumbing. Until the lead ban took
effect in 1988, most solder contained about 50 percent lead.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
A-5
-------
Term
Solubility (Lead or
Copper) Chart
Soluble/Insoluble
Standard 61, Section 9
Water Distribution
System
Water Quality
Parameters (WQPs)
Definition
Used to predict the theoretical amount of lead or copper that may be released
in a water under specific water quality conditions (pH and DIG levels). They can
be used as a general indication of the impact that changing water quality
conditions may have on lead and copper release and its control.
A substance which dissolves in a liquid is termed soluble. A substance that does
not dissolve or has very low solubility is termed insoluble.
A standard developed by NSF International for American National Standards
Institute (ANSI) that limits the amount of lead that can be leached from
endpoint devices for water intended for human consumption.
Refers to the piping, devices, and related fittings that are used to carry a
system's drinking water to its users.
Used to help systems and primacy agencies determine what levels of CCT work
best for the system and whether this treatment is being properly operated and
maintained overtime. WQPs include: pH, temperature, conductivity, alkalinity,
calcium, orthophosphate, and silica.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
A-6
-------
Appendix B - Estimated Dissolved Inorganic Carbon (mg/L as C) based on Alkalinity and pH (with water
temperature of 25 degrees C and IDS of 200)1'2
Total
Alkalinity
0
2
6
8
10
12
14
16
18
20
22
24
26
28
30
35
40
45
50
55
60
65
6.4
0
1
T
Z.
3
4
4
5
6
7
8
9
10
11
11
12
13
15
18
20
22
24
26
29
6.6
1
1
i
2
3
4
4
5
6
7
7
8
9
10
10
11
13
15
16
18
20
22
24
6.8
1
1
i
2
3
3
4
4
5
6
6
7
8
8
9
10
11
13
14
16
18
19
21
7.0
1
1
i
2
2
3
3
4
5
5
6
6
7
8
8
9
10
12
13
14
16
17
19
7.2
1
1
i
2
2
3
3
4
4
5
5
6
7
7
8
8
9
11
12
14
15
16
18
7.4
1
2
2
3
3
4
4
5
5
6
6
7
7
8
9
10
12
13
14
16
17
7.6
0
2
2
3
3
4
4
5
5
6
6
7
7
8
9
10
11
13
14
15
16
7.8
0
1
2
2
3
3
4
4
5
5
6
6
7
7
9
10
11
12
14
15
16
8.0
0
1
2
2
3
3
4
4
5
5
6
6
7
7
9
10
11
12
13
15
16
8.2
0
1
2
2
3
3
4
4
5
5
6
6
7
7
8
10
11
12
13
14
16
PH
8.4
0
1
i
1
2
2
3
3
4
4
5
5
6
6
7
7
8
10
11
12
13
14
15
8.6
0
1
i
1
2
2
3
3
4
4
5
5
6
6
7
7
8
9
11
12
13
14
15
8.8
0
1
i
1
2
2
3
3
4
4
5
5
5
6
6
7
8
9
10
12
13
14
15
9.0
0
1
i
1
2
2
3
3
4
4
4
5
5
6
6
7
8
9
10
11
12
14
15
9.2
0
1
i
1
2
2
2
3
3
4
4
5
5
6
6
6
8
9
10
11
12
13
14
9.4
0
1
i
1
1
2
2
3
3
4
4
4
5
5
6
6
7
8
9
10
11
12
14
9.6
1
1
2
2
2
3
3
4
4
4
5
5
6
7
8
9
10
11
12
13
9.8
0
1
1
2
2
2
3
3
4
4
4
5
5
6
7
8
9
10
11
12
10.0
0
0
1
1
1
2
2
3
3
3
4
4
4
5
6
7
8
9
10
10
10.2
0
1
1
1
2
2
2
2
3
3
3
4
5
6
7
8
8
9
10.4
0
0
1
1
1
2
2
2
2
3
4
5
5
6
7
8
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
B-l
-------
Total
Alkalinity
70
75
80
85
90
95
100
125
150
175
200
225
250
275
300
325
350
375
400
6.4
31
33
35
37
40
42
44
55
66
77
88
99
110
121
132
143
154
165
176
6 6
26
27
29
31
33
35
37
46
55
64
73
82
91
100
110
119
128
137
146
68
22
24
26
27
29
30
32
40
48
56
64
72
80
88
96
104
112
120
128
7 0
20
22
23
25
26
28
29
36
43
51
58
65
72
80
87
94
101
109
116
7 7
19
20
22
23
24
26
27
34
41
47
54
61
68
75
81
88
95
102
108
74
18
19
21
22
23
25
26
32
39
45
52
58
65
71
78
84
91
97
104
7 6
18
19
20
21
23
24
25
31
38
44
50
57
63
69
76
82
88
94
101
78
17
19
20
21
22
23
25
31
37
43
49
56
62
68
74
80
86
93
99
80
17
18
19
21
22
23
24
30
37
43
49
55
61
67
73
79
85
91
97
8 7
17
18
19
20
22
23
24
30
36
42
48
54
60
66
72
78
84
90
96
PH
8 4
17
18
19
20
21
23
24
30
36
42
48
54
60
66
72
77
83
89
95
8 6
16
18
19
20
21
22
24
29
35
41
47
53
59
65
71
77
82
88
94
8 8
16
17
19
20
21
22
23
29
35
41
46
52
58
64
70
75
81
87
93
90
16
17
18
19
20
22
23
28
34
40
45
51
57
63
68
74
80
85
91
9 7
15
16
18
19
20
21
22
27
33
39
44
50
55
61
66
72
77
83
88
94
15
16
17
18
19
20
21
26
32
37
42
48
53
58
64
69
74
79
85
96
14
15
16
17
18
19
20
25
30
35
40
45
50
55
60
65
70
75
80
98
13
14
14
15
16
17
18
23
28
32
37
42
47
51
56
61
65
70
75
10.0
11
12
13
14
15
16
17
21
25
30
34
38
43
47
52
56
60
65
69
10.2
10
11
12
12
13
14
15
19
23
27
31
35
39
43
47
51
55
59
63
10.4
8
9
10
11
11
12
13
17
20
24
28
32
36
39
43
47
51
54
58
Shaded cells indicate chemically impossible condition. May indicate analytical quality or total dissolved solids (IDS) assumption error.
2 References: Butler, J. N. Cogley, D. R. 1998. Ionic Equilibrium Solubility andpH Calculations. John Wiley and Sons, New York, NY; Schock, M. R. 1981. "Response of Lead
Solubility to Dissolved Carbonate in Drinking Water." Jour. AWWA. 73:3: 36.
3The equilibrium constants are from: Plummer, L. N. and Busenberg, E. 1982. "Solubilities of Calcite Aragonite and Vaterite in C02-H20 Solutions Between 0 and 90°C, and an
Evaluation of the Aqueous Model for the System CaC03-C02-H20". Geochimica et Cosmochimica Acta (The Journal of The Geochemical Society and The Meteoritical Society). 46:
1011.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
B-2
-------
Appendix C - Investigative Sampling to Determine the Source of Lead and
Copper
Investigative sampling can be used to help identify the sources of lead and copper in tap water
samples for a specific building. This type of information can help water systems and building
owners determine the most effective lead source replacement strategy.
Systems can take two consecutive first draw 125 ml standing samples to identify whether the
faucet, the brass underneath the faucet, or both components are contributing to lead in a tap
water sample. Another method identified in the literature is collecting samples to develop
premise plumbing profiles. This method may be used to determine where metals are being
released within the premise plumbing system and service line and can provide information on
the stability and solubility of pipe scales within lead service lines (LSLs). A typical procedure is as
follows:
• The water utility first collects pipe material data and estimates the length and diameter
of plumbing in the home from the sample tap to the water main.
• After at least 6 hours of stagnation, water utility staff collects sequential 1 liter bottles
of water without turning off the tap, typically from a kitchen sink, until all of the
estimated volume in the pipe and service line has been collected (up to the water main,
typically 10 - 15 bottles). Smaller volumes (e.g., 125 ml) can be collected for the first
several samples to isolate potential sources of lead in the faucet from the underlying
plumbing materials (fixture, connectors, valves).
• As an option, the utility can filter a small volume of water from specific samples (e.g.,
approximately 200 ml) on-site using a 0.45 micron filter to determine the particulate vs.
dissolved portion of lead. A 'water hammer' sample can also be taken by rapidly
opening and closing the tap several times to provide an indication of the amount of
'loose' particulate on the pipe walls.
• Analyzing samples for lead, copper, zinc, iron and cadmium can provide useful co-
occurrence information that can used to identify potential sources of lead in the
plumbing network.
Exhibit C-l provides an example of a lead profile at a residential home with a LSI. The home
had 8 ft of copper pipe from the kitchen tap to the meter/LSL and 89 ft of LSI following that
(Del Toraletal., 2013).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems C-l
-------
30.00
25.00
0.00
Sitel
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Exhibit C.I: Example of a Lead Profile (Del Toral et al., 2013)
Note: the x-axis represents sequential samples (typically liters)
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
C-2
-------
Appendix D -Water Quality Data and Information Collection Forms
This Appendix contains the following forms:
D-l Water Quality Data -Raw Water
D-2 Water Quality Data -Entry Point
D-3 Water quality Data - Distribution System
D-4 LCR Compliance Data Summary
D-5 Treatment Process Information
D-6 Lead Service Line (LSL) Information
D-7 Distribution System Materials and Operation
These forms are also available electronically in the OCCTEvaluation Templates.
Important notes about these forms are below.
1) These are technical recommendations only, and can be changed by the primacy agency
to reflect system specific conditions and/or primacy agency needs.
2) These tables can be included in the system's Corrosion Control Treatment (CCT) study
report or submitted separately to the primacy agency.
3) The Environmental Protection Agency (EPA) approved analytical methods must be used
for regulatory sample analysis (§141.89(a)). Primacy agency approved analytical
methods may be used for analysis of additional samples. In some cases, this may include
use of field test kits.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems D-l
-------
Exhibit D.I: Water Quality Data - Raw Water
Exhibit D.I Water Quality Data - Raw Water1
SourreName (if more than one
source, copy thissection and
turn plate for each source)
5-ourcelD
SourceType
Parameter
Lead(mg/y
Copper [mg/Lj
pH
Alkalinity (mg/L asCaCO3)
H ard n ess ( mg/ L as CaCO2 )
Temperature { Cj
Calcium | mg/L as Ca)
Total Dissolved Solids(mg/L):
Conductivity (asu,mho/cm@ 25 '01
Total Chlorine I mg/L asCL)
FreeChlorine[rng/L asCI:J
Chloride |rng/L)
Suifate |mg/L)
Iron (mg/L)
Manganese (mg/L)
Silica (m&'LasSiOj)
Required Monitoring
No, of
Samples
Frequency
Duration of
Sampling
Recommended Monitoring
No. of
Samples
2
a
5
4
*
&
-
4
&
HA
NA
2
2
4
4
1
Frequency
2x/year
2x/year
every other
month
quarterly
quarterly
every other
quarterly
quarterly
every other
montti
NA
NA
2x/ve ar
2x/year
quarterly
quarterly
quarterly
Duration of
Sampling
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
NA
NA
lyear
lyear
lyear
lyear
lyear
System Data
No. of Sites
Mo, of
Samples
Date Range WhenSamples Were
CoHerted
Start
{dd/mm/yyyy)
End
Idd/mrn/yyyyt
Mi n kn u m
Value
Maximum
Value
Average
Value
"UndertheLead and Copper Rule, no raw water monitoring is required. Howev-er, if raw water monitoring data are available, this may assist ttie system in select ing the can-Qsicmcantml traatmentthatwill work best with the system's
water quality.
* EithertDtal dissdved solids orconductivity can be measured.
"•.- = - ::-=-;- :=^ =
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
D-2
-------
Exhibit D.2: Water Quality Data - Entry Point
Exhibit D.ZWaterCLuaJlty Data -Entry Point"
Source Name [if rare thanone
source, copy this section and
:or".plst& far each course!
Source ID
Source Type
Parameters
Leadlmg/Lj1
Copper(rng/Lf
pH
Alkallntty [mg/LasCaCOjl
art ho phosphate |mg/Las P|
Hardness [mg/LasCaCOjl
Temperature [*€]•
Calcium [mg/L as Ca}
Total Dissolved Sol ids ImgAl*
tonducttvfty [as. u.rtho/sr1 @> Z5 "cj:
Disinfectant Residuai1
Total chlorine [mg/L ascy
Free chlonne [wgfl ascy
Ch D' is ir"s-''''-i
5LJlfats[r^/L|
Iron (mg/L}
Msnggnese [Pig^Lj
5lllC3[ni£/LasSCy
Entry Point4
Required Monitoring under LCR
No. of
Samples
Frequency
Duration of
Sampling
Recommended Monitoring
No. of
Samples
1
1
12 •"'
12''
12
12
12
12
5
12
12*
L2S'
5
5
4
4
4
Frequency
Ix/year
Is/year
n onth ly
ranthry
rnonthty
n onth ly
nonthty
n onth fy
every rther
rsnth
r*1. onth ly
monthly
nonthty
svsry other
•waft
every 3th*r
nonth
quarterfy
•quarterly
quarterly
Duration of
sampling
lyear
1 yea r
lyear
lyear
lyear
lyear
Lyear
lyear
1 ysa r
I yew
iyear
3 year
lyear
lyear
lyear
Lyear
lyear
System Data
No. of Sites
No. of
Samples
Date Range WhenSamplesWere
Collected
Start
(dd/mm/yyyyt
End
[dd/mm/yyyyj
Minimum
Value
Maximum
Value
Average
Value
: Enter data for each entry pant. Copy sheet for mul Bpte entry points.
: Bther tota! desolved sd ids or conductivitv ^n be meas-ued.
3 Botf^ total and 'free i^dwine should be measured.
tf there itnotreatnent, therisysten eonly required to sample 3tth£ entry point: unless water (s piped a significant d (stance, or stored, between the raw water point and the entty point.
: in t if 3 15:3 "•=, :•= a. a 3:- = f':-^ !•-= =,-£t="- :=c = ' : ••: :"• s'l'iEii ::'-f^ :3ta::^ =^:. :••-=:'-=;_ 55.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
D-3
-------
Exhibit D.3: Water Quality Data - Distribution System
Exhibit D.3 Water Quality Data • Distribution Sybte n
Source Name (if more than one
source, copy this secti on and
complete for e ach source)
Source ID
Source Type
Parameter
ph
Alkalinitvlmg/LasCaCOs)
Orthophosphate (mg/Las P)
Hardness (mg/Las CaCOJ
Temperature ('C)
Calcium(mg/LasCa)
Total DissolvedSolidsfmg/L)1
Conductivity (as um bo/cm (8 25 'C)1
Disinfectant Residual'
Total Chlorine [mg/L as Cli)
FreeChlorine (mg/L as Cl J
Chloride (mg/L)
Sulfate (mg/L)
Iron (rtig/L)
Manganese (mgi'L)
Silica (mg/Las SiCh)
Required Monitoring under LCR
No. of
Samples
Frequency
Duration of
Sampling
Recommended Data Collection
No. of Sites
12:3i
6
12;a
6
1#
6
6
12
jj«
tt«
4
4
4
4
4
Frequency
monthly
monthly
monthly
monthly
monthly
monthly
monthly
monthly
monthly
monthly
quarterly
quarterly
quarterly
quarterly
quarterly
Duration of
Sampling
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
lyear
System Data
No. of Sites
No. of
Samples
Date Range When Sam pies Were
Collected
Start
(dd/mm/ywy)
End
(dd/mm/ywv!
Minimum
Value
Maximum
Value
Average
Value
" Bthertotal dissolved solids or conductivity can be measured.
'Both total andfree chlorine should be measured.
'Select a combination of sites at various oistarcesfrom the entry point.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
D-4
-------
Exhibit D.4: LCR Data Summary
Exhibit D.4 Lead and Copper Rul e (LCR) Data Summary
Parameters
Lead|mg/L)
Copper (mg/L)
First Round of RegulatedTap Samples
No. of
Samples
Minimum
Value
Maximum
Value
Average
90th
Percentile
flSamples^
0.015 mg/L for
leaders 13
mg/Lfor
copper
Sample Period
Start Date
(dd/mm/ww)
Sam pie Period
End Date
(dd/mm/vm!
Parameters
Lead (mg/L)
Copper (mg/L)
Second Round of Regulated Tap Samples
No. of
Samples
Minimum
Value
Maximum
Value
Average
90th
Percentile
(fSamples>
0.015 mg/L for
lead or > 13
rng/Lfor
copper
Sample Period
Start Date
(dd/mm/ww)
Sam pie Period
End Date
(dd/mm/wVY)
IntheLastlQYears
Lead { mg/L)
Copper (mg/L)
How Many Times Has the
90th Percentileof
Sampling Results
Exceeded the Action
Level1 for (indicate the
year in which these
occurred in parentheses)
1. Action Levels are 0.015 mg/Lfor lead and 1.3 me/Lfor copper.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
D-5
-------
Exhibit D.5: Treatment Process Information
Edi lit OS T rest rre n t Proces 3 1 •Tornrfo •
Vrt*: ' nJ.'cr^cj.ir*.nrc.nJ r.'c.n.«w. ij*yfeaf';.ikrq #a*w+/aa*?r\artpfKssses.
So urcs Name ' * - o* "t - 0-4
x> J-CE..CO yf tn'a sect 'on and
co-n D sts "o -ftici »ure|
5o.r:t D
io.r :?".->?
Trertfrm t Prooes s
-,.Tcvrnb«.
Second -vyDt: mT*cton
Corivtnto-s F frsts-
htTT*rar* Fittwton
ton Exchange
*-St 5-
Lirrv Softonig
R Kride AMiioi
HB/L«F>
UeTided Phosp-at*1
afc*
Otter Pnccsic
Other Po cess «
CtfeerCbanal Aiditka
C-wTca ^3^eq
ChOTia SneiC.
Cherncs San**£
ChanraiName**
C-vem'c: Sa^e*
CaratTntmcBt
Mvk VJT if ^fdcOle
CbonkHUsed and Oos^e
fiTappic*fc|.
Wotfts/Cwnrrerfti
PlHBet Ft-bieTrertrat
Wterttan 1C1 rf
applicable
CtariatPtmmeHua Dwagf
\itmtatHt)
i:r:=:
IfTiptementatiori
fcte|mmfY)yri
M0te^C«nrren-b
1 ncLioese'ce-'iifsc^ T*D c^ctrjt sothcphospriile r Sofc^'Corr^entsf 'e d.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
D-6
-------
Exhibit D.6: Lead Service Line Information
Exhibit D.6. Lead Service Line Information
Question
Response
Does your system have ANY full" or partial" le ad service lines (YES or NO)?
If YES, approximately how many full lead service lines are in place?
If YES, approximately how many partial lead service lines are in place?
What was the approximate range of years the lead service lines were installed (YYVY to YVYY)?
A full I«a1 service line refers to the pipe from the water main to the residence being lead pipe, see illustration below (Source: Sarvdvigetal., 2008).
' A pjrtiailead service line refers to only a portionof the pipe from the main to the residence being lead pipe. This could be the portion of the pipe that is under the control
of the utility or the portion of the pipe that is under the control of the property owner, see illustration be low (Source: Sandvig e t al., 2008).
Public Side Private Side
Internal
Plumbing
Isolation
Valve
Water,
Main
Gooseneck or pigtail
Water
Meter
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
D-7
-------
Exhibit D.7: Distribution System Materials and Operation
Eidibit 0.7 Distribution System n«terials and Operation
Question
VMien was yet ' =Et^=tE*E £L.*VEV i2<~P EtE'Z
|aocm§ULB6(a)(?
wh at pexer tag e of water mai ns ate un lined cast iron? what is
tre app'ox rr 3te total length of unlinedcastifon mains [feet|?
Provide any additional com me rctsondtstrlbuti on system
materials (e_£, Estal typesf.
M you fl ush yojr system [YE or NO)?
tfYES,how often do youfiush yoursystem?
Do you have dead-ends in your system that have ex perienced
waterquantyproblems [YBorHO)?
if yo u diloranjnate, do you use fiee di iorine period! caly
durinjtheyear|YESor KO|?
if YE,approx;matey how often sJoyou usef'eech or'ne
= ': =t iVitrjEE?
ffYB.approxiniateJy how tongis free ditoiine used? |l.e.
one week, one month, etc|
Do you have red water complaints?
If YE, how often do they occur? Rarefy [a few tfmes 3
year^Sometimes [monthly!, Begulariy [weeldyf
Uses your system puithase any wate'(YESor no|?
If YES, how much?
If tvariesbymont!! please Sst an average per month,
'A*at " E tite sou ne of t he pu fchased wate'?
:: .:- 'E.-E : ='• t: :'E'|E ;:t';rt-:E ,VE:E- :- t^';»-3=E
wate-f'orr. arothersyitem (YESorHO)?
If YB,p;easeste sr'be.
lfappicahte.,do yoi t~=v= D s^Et: :rars£ v:.-':i3?- art rtfe
nearfuture [i.e, in the next i-3 years] [YESo'tiOj?
IfYES, pease 'styourct-entcoaji; artandtfcecoagL art
you plan to use. Mease include the planned implement 3t on
tote.
Response
Cu'^ent Coagu ant Future Ooagu ant
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
D-8
-------
Appendix E - OCCT Recommendation Forms for Systems Serving < 50,000
People
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems E-l
-------
Exhibit E.I: Identification of Potential Corrosion Control Treatment Options
Exhibit,, .dedication of Potenta, Corrosion Centre- Tre^ent Optfcns
CCT Options
Raise pH
Raise DlC(alkalinity)
Add orthophosphate1
Add silicate
Add blended phosphate1
Put an X next to all
thatapply
Identify possible treatment chemicals orprocesses for the options identified (chemical formula or
common name)
^ororthophosphateand blended phosphate, provide in mg/Las P. Forblended phosphate, include the percent of the blend that is onhophospha:e
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
E-2
-------
Exhibit E.2: Evaluation of Secondary Impacts
Exhibit E.2: Evaluation of Secondary Impacts
Source Name ("if more than one source, copy this section and
complete for each source)
Source ID
Source Type
Questions
Is the chemical available (YES or N O) ?
Do you feel your current operators will have difficulty using
this chemical and ope rat ing the treatment?
What are the relative costs for each treatment option?
(High, Medium, Low) (Provide your be stestim cite, which
should include cost for the chemical, any equipment that
needs to be purchased, increased operator time, etc...)
(Indicate what dosage cost comparisons are based on.)
Will this treatment change potentially cause excessive
scaling (See OCCT Manual Exhibit 3-2)?
Additional Notes/Comments
Adjust pH
Adjust DIC (Alkalinity)
Add Orthophosphate
Add Silicate
Add Blended Phosphate
1 Complete f oreach corrosion control treatment option identified in Exhibit E. 1.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
E-3
-------
Exhibit E.3: Documentation of OCCT Recommendation
Exhibit E.3: Documentation of OCCT Recommendation
Source Name |'"rf mare than one sou ire,, copy this
section and complete fore*chsoun:ey
Source ID
Source Type
Identify Recommended Treatment Approach
RecommendedChemical a r Process
Recommended Dosage
Recommended Levels =rt the Entry Point
Minimum
hbnmurn
Average
Recommended Levels in the Distribution System
Minimum
Maximum
Average
Adjust pH
pH
PH
Adjust DIG (Alkalinity)
Alkalinity
(mg/LasCaCOj
Alkalinity
(mg/Las CsCO: •
Add Ortho phosphate
Add Silicate
Add Blended Phosphate
Inhibitor"
Inhibitor"
" FnrDrthDph:i;ph=t==nd bl = nd=d pnn;ph = t=. prDvida in m§/L =; P.
PRINTED NAME and Signature of Responsible Party f ram Public Water System
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
E-4
-------
Appendix F - Tools for Conducting Corrosion Control Studies
This appendix provides a description of tools that can be used to conduct desktop or
demonstration-type corrosion control studies. Note that the Lead and Copper Rule (LCR)
requires the use of specific types of studies - see Chapter 4 for regulatory requirements. This
appendix describes both the required types of studies and additional study tools that can be
used to help identify the best corrosion control treatment.
F.I Desktop Study Tools
Desktop study tools use analogous systems, charts and other information related to corrosion
control theory, and models to select appropriate corrosion control treatment strategies. These
tools are described below.
Analogous Systems33
Drinking water systems can evaluate and compare data from other systems with similar water
quality, treatment, and distribution systems (analogous systems) to help identify corrosion
control treatment options. A description of the raw source water, water treatment processes,
distribution system, source water usage, and the performance of their corrosion control
strategy should be included in the corrosion control study report. Systems may want to start
with neighboring water systems using the same aquifer or surface source. Systems can also
conduct a survey of similar systems to obtain this information; seek technical assistance from
engineering consultants or industry associations; or review literature sources, such as the
report by The American Water Works Association's (AWWA's) Water Industry Technical Action
Fund which provides information on lead, copper and other water quality information for 400
US water systems (AWWA, 1993). An additional resource is the Distribution System
Optimization Program developed by the Partnership for Safe Water and the Water Research
Foundation. Participating systems can benchmark their performance against utilities with
similar water quality issues.
Corrosion Control Treatment Theory
Chapter 3 contains significant background information on corrosion control treatment. This
information can help systems conduct their study and evaluate different treatment strategies.
33 Systems conducting a desktop study (with no demonstration testing) must conduct analyses based on documented analogous
treatments with other systems of similar size, water chemistry and distribution system configuration to meet the requirements
of the LCR.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems F-l
-------
Models34
Commercially available models can be used to evaluate corrosion characteristics of water and
to predict changes in those characteristics with changes in treatment. Note that mention of
trade names, products, or services does not convey, and should not be interpreted as
conveying, official Environmental Protection Agency (EPA) approval, endorsement, or
recommendation. They include:
• The Rothberg, Tamburini & Winsor Blending Application Package 4.0 (RTW) (AWWA,
2001), a computer program developed to evaluate water chemistry associated with
precipitation/coagulation and corrosion-related characteristics of water.
• CORRODE software (Reiber et al., 1997; Edwards and Reiber, 1997) is a chemical
equilibrium model for identifying corrosion problems and corrosion control strategies.
• WaterlPro is a water quality modeling program that determines lead and copper
solubility based on water quality characteristics, and provides guidance on specific
treatments to control lead and copper.
• MINEOL+ and PHREEOCI (Parkhurst and Appelo, 1999) are aqueous geochemical
models.
The RTW model predicts typical bulk parameter and scaling characteristics of the water (pH,
hardness, alkalinity, and the scaling potential Langelier Saturation Index (LSI)) with changes in
operating conditions. While it does not predict impacts on lead or copper release, this model
can be used to evaluate how treatment changes may impact the bulk water characteristics of
the finished water, which can be used with other tools (e.g., solubility diagrams) for that
purpose. Therefore, it is particularly useful in evaluating blended water quality conditions (i.e.,
how pH and dissolved inorganic carbon (DIG) may change when water from different sources is
blended). It may also be useful in estimating the feasibility of chemical additions in achieving
desired finished water quality conditions for control of lead and/or copper. However, it should
be reiterated that the outputs from the model related to calcium carbonate deposition are not
relevant to lead and/or copper corrosion control, except as an indication of the potential for
scaling in the system as a secondary impact. Also, it may not be useful in evaluating inhibitor
addition (phosphates and silicates).
The other models listed (MINEQL+, PHREEQCI, and CORRODE, a module designed to interface
with MINEQL+) are public domain chemical equilibrium models. These models are relatively
complex, but may provide useful information to systems and primacy agencies if results are
generated by experienced personnel.
34 Mention of commercial software does not imply endorsement by the EPA. The RTW Model for Corrosion Control and Process
Chemistry 4.0 is available for purchase through the AWWA bookstore, at awwa.org. Corrode software is available from the
Water Research Foundation (formerly the American Water Works Research Foundation), Report 90712B. MINEQL1" version 5.0
is currently available for purchase through Environmental Research Software (www.mineql.com), and PHREEQCI is available as
a free download from the U.S. Geological Survey (http://wwwbrr.cr.usgs.gov/projects/GWC coupled/phreeqci/).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems F-2
-------
Systems and primacy agencies should consider additional cautions in using modeled data. None
of the models are valid for scaling potential in the presence of phosphates, silicates or natural
organic matter (MOM), and some trace metals that inhibit nucleation and growth of CaCOs.
Calcite may not be the proper solid phase in some systems. Utilities with corrosion inhibitors or
naturally occurring scale inhibiting factors should consider marble testing or field studies to
predict scale potential.
F.2 Demonstration Study Tools
This section describes coupon tests, pipe loop studies, solid and scale analysis, and partial
system tests. Several documents can be referenced for more detailed information on the
usefulness and relative costs of these tools (Hill, 2011; USEPA, 2007d; AWWA, 2005; Kirmeyer
et al., 2004; USEPA, 1992a; AwwaRF, 1990). A guidance document prepared by the Ontario
Ministry on Environment (MOE, 2009) provides a summary of these different tools, and
recommendations for the best tools to use given a system's size and complexity. This document
can be found at https://www.Ontario.ca/environment-and-energy/guidance-document-
preparing-corrosion-control-plans-drin king-water-systems.
Coupon Studies
Coupon studies use flat metal pieces (i.e., coupons) of lead, copper, iron, or steel to help
determine how specific corrosion control treatments (CCTs) may help prevent release of metals
from these materials. These coupons can be evaluated using a variety of different protocols
(static dump and fill, mounted in a flow-through pipe rig or mounted in the distribution system)
after which they can be taken out and weighed to determine total weight loss. Coupons can
also be used to measure the instantaneous corrosion rate of the metal using a variety of
electrochemical techniques (ASTM, 2005; AwwaRF, 1990; Schock, 1996; USEPA, 2007d). It is
important to note that coupon studies can be useful in determining the corrosion rate, but may
have limited use in predicting the concentrations of lead or copper in the water (Schock, 1996).
Pipe Loop Testing
Pipe loops consist of pipes or pipe sections made of a variety of materials, including lead pipe
(new or excavated), copper pipe, copper pipe with lead soldered joints, or brass components
(faucets or meters). Pipe loop studies can be designed as either flow-through systems (where
water flows through the apparatus once and is discharged to waste) or as recirculating systems
(where a batch of water is continuously recirculated through the loops for a set period of time).
There are several references that provide detailed information on the design and operation of
pipe loop systems (Schock and Lytle, 2011; AwwaRF, 1990; and Kirmeyer et al., 1994). Pipe
loops may need to be operated for several months or years to develop scales that are similar to
what would be found on premise piping in the system, and to measure stable metal levels. One
limitation of pipe loops is that they do not provide indication of contribution of lead release
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems F-3
-------
from physical disturbances that occur as part of routine system operations, maintenance and
repairs.
Scale and Solids Analysis
The analysis of actual pipe scale, and solids released from pipe scales, can provide an
understanding of their composition and role in release of lead and/or copper to the water.
These types of analyses may be particularly valuable to larger systems with lead service lines
(LSLs) that are contemplating a water quality and/or treatment change (particularly a switch
from free chlorine to chloramines for disinfection). Many techniques are available to examine
the scale: visual inspection, X-ray emission spectroscopy, X-ray diffraction, X-ray fluorescence,
Raman spectroscopy, inductively coupled plasma mass spectroscopy (ICP-MS), and scanning
electron microscopy with energy dispersive spectroscopy (EDS). There is currently no
standardized approach for evaluating pipe scales and solids, but there are references that
provide information on the application of these techniques and typical results (Smith et al.,
1997; Sandvig et al., 2008; Rego and Schock, 2007).
Partial System Testing
CCTs can be evaluated full-scale by applying the treatment to a hydraulically isolated portion of
the distribution system. Systems can collect samples from residential taps for lead and copper
analysis and additional water quality parameters in the distribution system. Partial system
testing can be relatively expensive, but it does provide a direct means for examining the
potential secondary impacts of implementing a particular CCT and for monitoring the
implementation timeframes for installation of CCT (i.e., length of time needed for an inhibitor
to be effective).
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems F-4
-------
Appendix G - Forms for Follow-up Monitoring and Setting OWQPs
Appendix G supports Chapter 5 by providing data collection forms for follow-up monitoring and
technical recommendations for primacy agencies to consider when designating Optimal Water
Quality Parameters (OWQPs) for pH/alkalinity/dissolved inorganic carbon (DIG) adjustment,
orthophosphate treatment, blended phosphate treatment, and use of a silicate inhibitor.
This appendix contains the following forms:
G-l Results of Follow-up Lead and Copper Tap Monitoring.
G-2 Results of Follow-up WQP Monitoring - Entry Point.
G-3 Results of Follow-up WQP Monitoring - Taps.
G-4 Setting OWQPs for pH/Alkalinity/DIC Adjustment.
G-5 Setting OWQPs for Orthophosphate Inhibitor Addition.
G-6 Setting OWQPs for Blended Phosphate Inhibitor Addition.
G-7 Setting OWQPs for Silicate Inhibitor Addition.
These forms and recommended procedures are also available electronically in the OCCT
Evaluation Templates.
Important notes about these forms are below.
1) The Environmental Protection Agency (EPA) approved analytical methods must be used
for regulatory sample analysis (§141.89(a)). Primacy agency approved analytical
methods may be used for analysis of additional samples. In some cases, this may include
use of field test kits.
2) The procedures in Exhibits G-4 through G-7 are technical recommendations only, see
Chapter 5 for requirements for primacy agencies in setting OWQPs.
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems G-l
-------
Exhibit G.I: Results of Follow-up Lead and Copper Tap Monitoring
Exhibit G.I Results o' Follow-up Lead and Copper Tap Monitoring
Parameter
Lead (mg/L)
Copper {mg/L}
Required by the Primacy Agency
No. of Tap
Sites
Frequency
Duration of
Sampling
PWS Data
No. of
Sites
No. of
Samples
Date Range When Samples Were Collected
Start (dd/mm/yyw)
Endfdd/mm/wyy)
Minimum
Value
mg/L
mg/L
Maximum
Value
mg/L
mgA.
Average Value
mg/L
mg/L
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
G-2
-------
Exhibit G.2: Results of Follow-up WQP Monitoring - Entry Point
Exhibit Q. 2 Results of Fol low-up WQP Yl onitoring - Entry Poi nt1
Source Name (if more than one source or
multiple entry points/source, copy this
section and complete foreach
source/entry point combination)
Source ID
Source Type
Parameter
pH
Alkalinity (mg/L as CaCOj)
Inhibitor Concentration (phosphate
inhibitor in mg/L as P(not as
orthophosphate); silicate inhibitor in mg/L
as SiOj)
Hardness (mg/L as CaCO3)
Temperature (-C)
Calcium (mg/L as Ca)
Total Dissolved Solids (mg/L)2
Disinfectant Residual
Total Chlorine (mg/L as CIJ
Free Chlorine (mg/L as CI2)
Chloride (mg/L)
Sulfate (mg/L)
Iron (mg/L)
Manganese (mg/L)
Required by the Primacy Agency
Frequency
Duration of
Sampling
PWSData
No. of Samples
Date Range When Samples Were Collected
Start (dd/mm/yyyy)
End (dd/mm/yyyy)
Minimum
Value
Maximum
Value
Average Value
" Enter data for each entry point Copy sheet for multiple entry points.
J Ert he rTotal Dissolved Solids or Conductivity (asumhos/cm @25CoruS/cm )
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
G-3
-------
Exhibit G.3: Results of Follow-up WQP Monitoring - Taps
Exhibit Q. 3 Results of Foil ow-up WQP Monitoring -Tap Samples1
Source Name Associated with tap samples
(if there are additional tap samples
associated with a different source, copy this
section and completeforeach source/tap
sample set. If multiple sources are associated
with the tap samples listed below, list all
source s he re)
Source ID(s)
Source Type
Parameter
pH
Alkalinity (mg/L as CaCOJ
Inhibitor Concentration (phosphate inhibitor
in mg/L as P (not as orthophosphate); silicate
inhibitor in mg/L as SiOj)
Hardness (mg/L as CaCCk)
Temperature ('CJ
Ca'c'um (mg/L as Ca)
Total Dissolved Solids (mg/L)2
Disinfectant Residual
Tola (Chlorine (mg/LasCI2)
Free Chlorine (mg/L as Ci2)
Chloride (mg/L)
Sulfate (mg/L)
iron (mg/L)
Man gan e s e ( mg/L j
Required by the Primacy Agency
No. of Tap
Sites
Frequency
Duration of
Sampling
PWS Data
No. of
Sites
No. of
Samples
Date Range When Samples Were Col lected
Start (dd/mm/yyyy)
End ( dd/mnWyyy]
Minimum
Value
Maximum
Value
Average Value
Tap should be flushed prior to collecting samplesf or all parameters except lead and copper which are standing samples.
EitherTotal Dissolved Solids or Conductivity (as u.mhos/cm tai 25 C oruS/cm )
OCCT Evaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
G-4
-------
Exhibit G.4: Setting OWQPs for pH/Alkalinity/DIC Adjustment
Exhibit G.4 Setti ng OWQPs for pH/AI ka! ini ty/DIC Adj ustment
Step 1: Are the recommended minimums or
ranges f or pH and/or alkalinity met at the Entry
Point and in the Distribution System?
Step 2: Is the range of pH values measured at the
Entry Point < 0.2 to 0.4 pH units (Range = Max entry
point pH - Min entry point pH)?
Step 3: Is the range of pH values measured in the
Distribution System < 0.4 to 0.6 pH units (Range =
Max distribution pH- Min distribution pH)?
YES
NO
YES
NO
YES
NO
Go to Step 2.
Work with system to re-evaluate pH and/or alkalinity adjustment
process.
Go to Step 3.
The pH range may be too wide for effective control of lead and/or
copper levels at the tap. Work with system to re-evaluate pH
adjustment process. Review process control charts for pH chemical
dosages and resultant pH levels. Evaluate seasonal changes in raw
source water quality and impacts on maintenance of pH at the entry
point.
Also go to Step 3.
Identify WQP minimums and ranges basedon existing system
information (both regulatory WQP monitoring data and additional
diagnostic monitoring data if available).
The pH may be too variable for effective corrosion control. Re-
evaluate pH adjustment process and reasons for variability in pH in
the distribution system (evaluate buffer intensity, distribution
system materials, distribution system operations). If low alkalinity
water (< 20 mgCaC03/L), may need to increase DIG.
lThe standard deviation is another tool that can be used to evaluate variability of pH measurements, in addition to the minimum,
maximum, and range.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
G-5
-------
Exhibit G.5: Setting OWQPs for Orthophosphate Inhibitor Addition
Exhibit G.SSetting OWQPs for Orthophosphate Inhibitor Addition
Step 1: Is the residual Orthophosphate level in the
distribution system > 1.0 mg P/L (> 3.0 mg/L PCu)?
Step 2: Are the minimum pH values measured at
the Entry Point > 7.2 pH units?
Step 3: Is the distribution system pH between 7.2
and 7.8 pH units?
Step 4: Is the range of pH values measured at the
entry point<0.4 pH units (Range = max entry point
pH - min entry point pH)?
Step 5: Is the range of pH values measured in the
distribution system < 0.6 pH units (Range = Max
distribution pH - Min distribution pH)?
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
Go to Step 2.
If system has recommended an Orthophosphate residual in the
distribution system that is<1.0mg P/L, then determine if inhibitor
chemical dosage needs to be increasedto provide optimal reduction
in lead and/or copper levels. If system has recommended an
Orthophosphate residual in the distribution system that is > LO mg
P/L, then evaluate Orthophosphate demand in the system
(difference between entry point Orthophosphate versus residual
Orthophosphate in the distribution system) and potential for
adjusting required dosage to meet recommended residual in the
distribution system.
Go to Step 2.
Go to Step 3.
Minimum pH should be higher for Orthophosphate use. Have system
re-evaluate pH adjustment process, or raise pH if 7.2 or below.
Go to Step 4.
The pH is not in the optimal range for use of Orthophosphate
inhibitors. Have system re-evaluate the pH control treatment
process, pH variability in the distribution system, and adequacy of
recommended Orthophosphate dosage and residual in the
distribution system.
Goto StepS.
The pH may be too variable for effective corrosion control. System
should re-evaluatethe pH adjustment process (i.e., review process
control charts and operations).
Identify OWQP minimums and ranges based on existing information
(both regulatory WOP monitoring data and additional diagnostic
monitoring data if available).
Evaluate causes for pH variability in the system. Evaluate buffer
intensity, distribution system materials, and distribution system
operations, and adjust treatment and operations to achieve a
narrower range of pH and alkalinity.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
G-6
-------
Exhibit G.6: Setting OWQPs for Blended Phosphate Inhibitor Addition
Exhibit G.6 Setting OWQPs for Blended Phosphate Inhibitor Addition
Step 1: Is the residual orthophosphate level in the
distribution system > 0.5 mg P/L?
Step 2: Are the minimum pH values measured at
the entry point >7.2pH units?
Step 3: Is the distribution system pH between 7.2
and 7.8 pH units?
Step4: Is the range of pH values measured at the
entry point < 0.4 pH units (Range = max entry point
pH - min entry point pH}?
Step 5: Is the range of pH values measured in the
distribution system < 0.6 pH units (Range = max
distribution pH - min distribution pH)?
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
Go to Step 2.
If system has recommended a blended phosphate product dose that
results in an orthophosphate residual of < 0.5 mg P/L in the
distribution system, then determine if inhibitor chemical dosage
needs to be increasedto provide optimal reduction in lead and/or
copper levels. If system has recommended an orthophosphate
residual in the distribution system that is >0.5 mg P/L, then evaluate
orthophosphate demand in the system (difference between entry
point orthophosphate versus residual orthophosphate in the
distribution system) and potential for adjusting required dosage to
meet recommended residual inthe distribution system.
Go to Step 2.
Goto Step 3.
Minimum pH should be higher for orthophosphate use. Have system
re-evaluate pH adjustment process, or raise pH if 7.2 or below.
GotoStep4.
The pH may not be inthe optimal range when using blended
phosphate inhibitors, check with the chemical supplier for optimal
pH range. Have system re-evaluate the pH control treatment
process, pH variability in the distribution system, and adequacy of
recommended orthophosphate dosage and residual inthe
distribution system.
Go to Step 5.
The pH may be too variable for effective corrosion control, check
with the chemical supplierto verify quality of the product used to
adjust pH. System should re-evaluate its pH adjustment process
(process control charts and operations).
Identify OWQP minimums and ranges based on existing information
(both WQP monitoring data and additional diagnosticmonitoring
data if available).
Evaluate causes for pH variability in the system. Evaluate buffer
intensity, distribution system materials, distribution system
operations and adjust treatment and operations accordingly.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
G-7
-------
Exhibit G.7: Setting OWQPs for Silicate Inhibitor Addition
Exhibit G.7 Setting Optimal WQPs for Silicate Inhibitor Addition
Step 1: Is the silicate level at the entry point
approximately 20mg/Las SiO2?
Step 2: Is the pH at the entry point less than the pH
measured in the distribution system?
Step 3: Isthe range of silicate levels measured in
the distribution system from 10to20mg/Las SiO??
YES
NO
YES
NO
YES
NO
Go to Step 2.
Silicate addition process should be re-evaluated. Relatively high
dosages may be required (in excess of 20mg/Las SiO2, depending
on the system) foradequate corrosion control.
Go to Step 3.
Silicate addition process should be re-evaluated. Silicate addition
should increase pH in the distribution system, so recommended
dosage may not be high enough for adequate corrosion control.
Identify OWQP mini mums and ranges based on existing information
(both regulatory WQP monitoring data and additional diagnostic
monitoring data if available).
Re-evaluation of silicate treatment should be completed. Relatively
higher dosages may be required (in excess of 20mg/L) in order to
maintain adequate levels in the distribution system for effective
corrosion control.
OCCTEvaluation Technical Recommendations for
Primacy Agencies and Public Water Systems
G-8
------- |