Revised Guidance
\ Manual for Selecting
Lead and Copper
Control Strategies
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Office of Water
(4606M)
EPA-816-R-03-001
www.epa.gov
March 2003
l Printed on Recycled Paper
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Revised Guidance Manual
for Selecting Lead and Copper
Control Strategies
Prepared by
Catherine M. Spencer, P.E.
Black & Veatch
Pownal, ME 04069
Prepared for
The Cadmus Group, Inc
57 Water Street,
Watertown, MA 02472
Under Contract with the U.S. EPA No. 68-C-99-245
Drinking Water Protection Division
Office of Ground Water and Drinking Water
Office of Water
U. S. Environmental Protection Agency
Washington, DC 20460
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Disclaimer
The Safe Drinking Water Act provisions and EPA regulations described in this document contain
legally-binding requirements. This document does not substitute for those provisions or
regulations, nor is it a regulation itself. Thus, it does not impose legally-binding requirements on
EPA, States, or the regulated community, and may not apply to a particular situation based upon
the circumstances. EPA and State decision makers retain the discretion to adopt approaches on a
case-by-case basis that differ from this guidance where appropriate. Any decisions regarding a
particular facility will be made based on the applicable statutes and regulations. Therefore,
interested parties are free to raise questions and objections about the appropriateness of the
application of this guidance to a particular situation, and EPA will consider whether or not the
recommendations or interpretations in the guidance are appropriate in that situation. EPA may
change this guidance in the future. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
in
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ACKNOWLEDGMENTS
The original document, Guidance Manual for Selecting Lead and Copper Control Strategies, was
prepared for Peter Lassovszky, U.S. Environmental Protection Agency in January 1997. The
original,1997, and revised, 2003, manuals were developed by Black & Veatch under subcontract to The
Cadmus Group. The primary author of the original manual was Jonathan Clement (Black & Veatch),
with assistance from Michael Schock (U. S. Environmental Protection Agency, National Risk
Management Research Laboratory, Water Supply and Water Resources Division), and Wendy Marshall
(U.S. Environmental Protection Agency, Region 10). The primary author of the revised manual was
Catherine M. Spencer, P.E. (Black & Veatch).
We would like to acknowledge the valuable contribution of the following State contacts to this effort:
Ron Cramer, Kansas Department of Health, Steve Jillson, Environmental Engineer I and Steve Drda,
Monitoring and Compliance Coordinator, Nebraska Health and Human Services; James Melstad,
Montana Department of Environmental Quality; Robin Michaels, Arkansas Department of Health;
John R. Payne, Colorado Department of Health; and Lih-In Rezania, P.E., Public Health Engineer,
Minnesota Department of Health.
EPA also appreciates the technical support provided by Anne Jaffe Murray of The Cadmus Group,
Inc., the prime contractor for this project.
IV
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TABLE OF CONTENTS
Foreward 1
Introduction 2
Why should we monitor for lead and copper? 2
Why do we need to sample tap water? 3
What do we do next? 3
Background on Corrosion Control for Lead and Copper 3
pH 4
Alkalinity 4
Dissolved Inorganic Carbonate (DIG) 4
Hardness 5
Orthophosphate 5
Buffer Intensity 5
Dissolved Oxygen/Chlorine Residual 6
Directions for Making Treatment Determinations 7
Section 1 Flow Chart Treatment Determinations 11
Section 2 -Water Treatment Considerations 32
Section 3 - Optimizing Treatment 40
Section 4 - Example Treatment Determinations 41
Section 5 - Some Additional Sources of Information 45
Appendix A
Questionnaire to Collect Data to Update the Guidance Manual
for Selecting Lead and Copper Control Strategies A-l
Appendix B
Summary of Data from Questionnaire B-l
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LIST OF TABLES
Table 1: Metals Limits in Drinking Water and Wastewater Effluents 9
Table 2: Metals Limits in Land Residual 9
Table 3: Dissolved Inorganic Carbonate Determination 13
Figure 1: Saturation pH for Calcium Carbonate Precipitation 18
Sheet 1A: Exceeded Lead and Copper Action Levels 19
Sheet 2A: Exceeded Lead and Copper Action Levels 20
Sheet 3A: Exceeded Lead and Copper Action Levels 21
Sheet IB: Exceeded Lead Action Level Only 22
Sheet 2B: Exceeded Lead Action Level Only 23
Sheet 3B: Exceeded Lead Action Level Only 24
Sheet 1C: Exceeded Copper Action Level Only 25
Sheet 2C: Exceeded Copper Action Level Only 26
Sheet 3C: Exceeded Copper Action Level Only 27
Sheet ID: Exceeded Lead and/or Copper Action Levels
and Have Raw Water Iron or Manganese 28
Sheet 2D: Exceeded Lead and/or Copper Action Levels
and Have Raw Water Iron or Manganese 29
Sheet 2E: Exceeded Lead and/or Copper Action Levels
and Have Raw Water Iron or Manganese 31
Sheet 4A: Aeration Feasibility Tree 34
Sheet 4B: Limits of Aeration 35
Sheet 5A: Limestone Contactor Feasibility Tree 36
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List of Acronyms and Abbreviations
C/L
Ca
CaCO3
CCT
co32-
Cu
DIG
DBF
HCO3
LCR
MDBP
mg/kg
^g/L
mg/L
OGWDW
P
Pb
P04
THMs
WQP
Carbon per liter
Calcium
Calcium carbonate
Corrosion control treatment
Carbonate ion
Copper
Dissolved inorganic carbon
Disinfection byproduct
Bicarbonate ion
Lead and Copper Rule
Microbial and Disinfection Byproducts Rules
Milligrams per kilogram
Micrograms per liter
Milligrams per liter
Office of Ground Water and Drinking Water
Phosphate
Lead
Orthophosphate
Trihalomethanes
Water quality parameter
Revised Guidance Manual for
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March 2003
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Revised Guidance Manual for Selecting
Lead and Copper Control Strategies
Fore ward
In 1996, the Office of Ground Water and Drinking Water (OGWDW) of the U.S. Environmental
Protection Agency was interested in developing a simple guidance that could be used by regulators,
small water systems, and their engineers to aid in initially determining what treatment approaches for
lead and copper control would have the best chance of success. The original document, Guidance
Manual for Selecting Lead and Copper Control Strategies, was prepared in January of 1997.
In the five years since the completion of the manual, many water systems have successfully employed
corrosion control treatment to achieve compliance with the Lead and Copper Rule. However, the
information in the manual is still timely and relevant, because some systems still have difficulty in
sufficiently reducing lead and copper corrosion, and other systems may need to change water treatment
approaches because of other regulatory issues or changes in water sources. In particular, groundwater
systems in the midwest with neutral pH value, high hardness, and high alkalinity water have had
difficulty meeting the copper action level. Thus, corrosion control for lead and copper has been
revisited in the context of these considerations.
EPA decided to take advantage of the considerable corrosion control treatment experience that had
been gained over the past five years to refine (or even sometimes correct) the recommendations for
treatment selection. The manual has been updated with:
Information on aeration and limestone contactors for corrosion control;
The most successful treatments for copper corrosion control in high alkalinity/high
dissolved inorganic carbonate (DIG) waters;
Tradeoffs of corrosion control with iron and manganese removal; and
Considerations for corrosion control in light of the new (1994) water quality based
standards for wastewater treatment.
In addition, the document has been streamlined to make it more responsive to users. Thus, this manual
has been revised and edited to help provide readers with the best general screening-level guidance that
current knowledge permits.
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Data were gathered from a number of sources and State contacts were very valuable to this effort. We
would like to acknowledge:
Ron Cramer, Kansas Department of Health
Steve Jills on, Environmental Engineer I and Steve Drda, Monitoring and Compliance
Coordinator, Nebraska Health and Human Services
James Melstad, Montana Department of Environmental Quality
Robin Michaels, Arkansas Department of Health
John R. Payne, Colorado Department of Health
Lih-In Rezania, P.E., Public Health Engineer, Minnesota Department of Health.
Introduction
The objective of this manual is to assist water systems and regulatory agencies with selecting and
approving effective treatment strategies for controlling lead and copper in drinking water. The
selection of a treatment strategy for lowering lead, copper, or lead and copper levels in drinking water
from corrosion of plumbing materials depends on numerous site-specific factors that cannot be
addressed in this manual. Therefore, to address these site-specific factors, water systems should seek
out the advice of water treatment professionals when selecting a treatment strategy.
Why should we monitor for lead and copper?
The National Primary Drinking Water Regulations for Lead and Copper (also called the Lead and
Copper Rule or LCR) became effective in 1991. The LCR requires all community and non-transient
non-community water systems to monitor for lead and copper at a specified number of taps within
homes and/or buildings served by that water system. It also establishes treatment technique
requirements including corrosion control treatment, source water treatment, lead service line
replacement, and public education. These requirements may be triggered if more than 10 percent of tap
water samples collected during any monitoring period exceed the lead action level and/or the copper
action level. The action level for lead is 0.015 mg/L. The copper action level is 1.3 mg/L.
Lead and copper are being regulated because of the possible negative health effects associated with
drinking water containing these two contaminants. Health effects associated with exposure to lead in
infants and young children include lower birth weight and a slowing down of normal physical and
mental development which may result in lower IQ levels, damaged hearing, reduced attention span and
poor classroom performance. Impacts to adults may include kidney damage, slight increases in blood
pressure, and damage to the reproductive system. In addition, high levels of nitrate may magnify these
adverse health effects.
While drinking water with high levels of copper should not cause long-term health effects like lead,
high copper levels in drinking water can cause very uncomfortable gastrointestinal effects such as
nausea and diarrhea, and can magnify adverse effects of nitrate ingestion, especially in children.
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Why do we need to sample tap water?
High levels of lead and copper are rarely found in the water that a water system provides to its
customers. The main sources of lead and copper in drinking water usually are plumbing materials made
from copper; lead service lines and lead solder, commonly used before 1990 to join lengths of copper
pipe together; and faucets containing brass or bronze internal parts, which usually contains lead
impurities. Under the 1996 Amendments to the Safe Drinking Water Act, "lead free" brass can contain
as much as 8 percent lead by weight, which is enough to contribute significant amounts to lead to tap
water samples. If the water provided by your water system is highly or even moderately corrosive,
some of the lead and/or copper in the plumbing materials may be released into the drinking water in
houses or buildings served by your water system.
A sampling program that measures lead and copper levels at the tap helps to determine if a water
system is providing corrosive water. Those water systems found to be providing corrosive water are
required to install corrosion control treatment to lower the corrosivity of the water, which should then
result in lower lead and copper levels at the users' taps.
What do we do next?
The federal Lead and Copper Rule requires all water systems that have exceeded the lead action level,
the copper action level, or both action levels to recommend a corrosion control treatment method that
will minimize lead and copper levels at users' taps. In addition, water systems may be required to
perform corrosion control studies to evaluate the most effective corrosion control treatment method.
The objective of this guidance manual is to assist small water systems with selecting the appropriate
treatment strategy and to provide assistance to State regulatory agencies that approve treatment plans
for the water systems within their jurisdiction.
Background on Corrosion Control for Lead and Copper
Lead and copper entering drinking water from household plumbing materials such as pipes, lead solder
and faucets containing brass or bronze, can be controlled by changing water quality characteristics. The
water quality factors that have the greatest affect on lead and copper corrosion are pH, dissolved
inorganic carbonate (DIG), orthophosphate concentration, alkalinity, and buffer intensity. Dissolved
oxygen and/or chlorine residual are also important considerations for copper. There are many other
factors that affect the corrosion of lead and copper, but they cannot be easily altered by a water system
and have a lesser effect on corrosion. Alkalinity, which is interrelated with pH and DIG, is often
measured by water systems. Buffer intensity, which is also interrelated with pH and DIG, is an
additional parameter that is very important in maintaining optimal corrosion control and water quality
out in the distribution system.
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pH
The pH of a water is a measure of acidity, otherwise known as hydrogen ion concentration (H+
or H3O+). pH values can range from 0 to 14, and the lower the value the more acidic the water.
Most drinking waters range from 6 to 10. One common corrosion control treatment strategy is
to raise the pH of the source water. This can be done through chemical or non-chemical
means. Any increase in pH within the pH range of 5 to 10 should result in a decrease in lead
and copper levels. At the higher pHs, there is less tendency for lead and copper to dissolve and
enter drinking water. The pH of water can vary significantly as water moves through the
distribution system. Although the pH measured at the pump station or treatment facility may
appear to be stable, as it passes through the distribution system it may increase or decrease
significantly. This will depend on the size of the distribution system, flow rate, age and type of
plumbing material. It is important to maintain the target pH throughout the distribution
system, so that lead and copper levels can be minimized at the tap.
Alkalinity
Alkalinity is the capacity of water to neutralize acid. It is the sum of carbonate, bicarbonate and
hydroxide anions. Alkalinity is typically reported as mg/L "as calcium carbonate" (CaCO3).
Low alkalinity water will not neutralize acids well, while high alkalinity water will. For most
surface waters, alkalinity varies with the seasons as snow melt or spring rain runoff decreases
alkalinity; algal growth can affect alkalinity as can drought. Groundwater alkalinity tends to be
more stable. Waters with high alkalinities also tend to have high buffering capacities, or in
other words, a strong ability to resist changes in pH brought about by chemical dosing or water
quality changes in the distribution system.
Dissolved Inorganic Carbonate (DIG)
DIG is an estimate of the amount of total carbonates in the form of carbon dioxide gas (CO2 or
H2CO3), bicarbonate ion (HCO3~), and carbonate ion (CO32~) in a particular water. It is
measured as milligrams of carbon per liter (mg C/L). DIG is related to alkalinity in that if you
know the pH and alkalinity of a water, you can predict the DIG. The level of DIG affects levels
of lead and copper and affects the stability of the pH. The amount of DIG relates to the
buffering of the water. The buffering of a water is its ability to resist a change in pH. If a water
has minimal DIG, then the pH may fluctuate significantly. Because of the high sensitivity of
copper and lead to pH, the improved pH control of a minor DIG increase to raise buffering
(i.e., 3-6 mg C/L) offsets potential increases in copper levels. Therefore, balancing the amount
of DIG for lead, copper, and buffering is an important part of corrosion control.
At a constant pH, as the DIG increases, copper levels should increase. The effect of DIG is not
as strong as the effect of pH until high (> 30 mg C/L) levels of DIG are reached, when pH
adjustment stops being an effective treatment approach. Increases in DIG of 3-6 mg C/L will
typically have minimal impact on copper levels, particularly with respect to the regulatory action
level. In contrast, for control of lead, as the DIG increases the lead concentration decreases or
remains essentially unchanged within the pH range of about 7.0 to 8.0. At higher pHs there will
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be very little impact of DIG on lead levels or there may be a very slight increase in lead levels
with increasing DIG.
Hardness
Hardness is a measure of the amount of calcium and magnesium in the water. Hardness is
usually measured with the combined calcium and magnesium and reported "as CaCO3", that is
as calcium carbonate. Obtaining calcium data as mg/L is also very helpful or an estimate of
calcium levels can be made from hardness "as CaCO3" data by dividing the hardness number by
2.5. The calcium and magnesium compounds can interfere with corrosion control efforts
because they are less soluble at higher pH values than at lower pHs. Hardness must be taken
into consideration when corrosion control is selected and implemented because it can cause
unintended side affects such as increased scaling, both within the pump station/treatment plant
or out in the service area.
Orthophosphate
Orthophosphate (PO4) added as a corrosion control treatment chemical can combine with lead
and copper in plumbing materials to form several different compounds. These compounds do
not have a strong tendency to dissolve. As a result, lead and copper levels in the water will
remain low. The key to ensuring that Orthophosphate will reduce lead and copper levels is to
maintain the proper pH and Orthophosphate residual. Residual Orthophosphate is the free
amount of Orthophosphate measured in the distribution system. It is very important for most
water systems to maintain a residual of at least 0.5 mg/L Orthophosphate as phosphate (P) and
if, possible a residual of 1 mg/L as P is preferable. In many cases, water systems maintain a
residual that is too low, thus making the Orthophosphate treatment ineffective. When using
Orthophosphate for lead and copper control, the pH should be maintained within the range of
7.2-7.8. If the pH is too low, even high dosages of Orthophosphate will not work. At high pH,
poor corrosion-protecting film stability has often been observed. Much higher concentrations
are often needed to resolve copper problems than lead problems. Treatment chemicals
containing zinc will help protect cement and cement mortar-lined pipes. When copper or zinc
concentrations in wastewater discharge or sludge are of concern, pH/DIC adjustment to
control copper corrosion is usually preferable if feasible for the water quality.
Buffer Intensity
Buffer intensity is a measure of the resistance of a water to changes in pH, either up or down.
Bicarbonate and carbonate ions are the most important buffering species in almost all drinking
waters. At high pH (over 9), silicate ions also supply buffering. Phosphate contributions are
normally insignificant as long as DIG is approximately 5 mg/L as C or greater. Buffering is
normally greatest at approximately pH 6.3, decreases towards a minimum at a pH of between
about pH 8 and 8.5, and then again gets increasingly higher as pH goes above 9. Thus, treated
waters in this very low buffer intensity pH range (8 - 8.5) tend to have highly variable pH in the
distribution network. This is aggravated in waters that have very low amounts of DIG (less
than about 10 mg C/L). Waters with low buffer intensity are prone to pH decreases from such
sources as uncovered storage, nitrification, corrosion of cast iron pipe, and pH increases from
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contact with cement pipe surfaces. Maintaining sufficient buffering is very important when
using orthophosphate addition or pH adjustment, because copper and lead control require
particular pH ranges to be effective. Even if the pH of the water leaving the treatment plant is
correct, pH changes in the distribution system may nullify the intended corrosion control
treatment.
Dissolved Oxygen/Chlorine Residual
Dissolved oxygen is a measure of the amount of oxygen dissolved in water. Oxygen is slightly
soluble in water, seldom reaching concentrations exceeding 15 mg/L and in some ground
waters, it is absent or below detection levels. However, adding dissolved oxygen can have a
great effect on water quality as it oxidizes dissolved reduced iron and manganese (more slowly)
and forms more soluble copper compounds than waters with no dissolved oxygen. This is a
consideration for aeration for either iron oxidation or for corrosion control. The benefits of
carbon dioxide removal and pH rise from aeration must be balanced against the possibility of
creating soluble copper in the distribution system from increased dissolved oxygen addition.
The addition of chlorine to a groundwater source that has low dissolved oxygen has the same
effect as adding dissolved oxygen on the chemistry of the water. Systems that have to add
chlorine to meet the Groundwater Disinfection Rule may find increased copper corrosion,
necessitating a revision of corrosion control.
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Directions for Making Treatment Determinations
Selecting viable a treatment option for controlling lead and copper is a five-step process:
Step 1: Examine the lead and copper data. Because small water systems collect so few samples,
it is important to ensure that an action level exceedance is due to corrosive water, rather
than some other cause. Water with pHs greater than 7.8 and with alkalinities between 30
and 100 mg CaCO3/L would generally not be considered corrosive. (Water with an
alkalinity greater than 100 mg CaCO3/L is frequently highly corrosive toward copper.) If
the water quality data are in the non-corrosive range but there are some unusual lead or
copper numbers, then the possibility of re-sampling or materials replacement should be
discussed with the primacy agency. A few minutes educating customers regarding proper
sampling for lead and copper may save extensive and expensive adjustment of the
treatment.
Step 2: Collect accurate and sufficient background chemistry information to characterize
the water and anticipate future regulatory requirements. Although it initially appears
to be expensive to collect many water samples and analyze a broad range of water quality
constituents, doing so can save tens or hundreds of thousands of dollars of added expenses
later in revising treatment plants or adding new processes that were not anticipated. Having
very accurate pH and alkalinity/DIC data is absolutely necessary to know the feasibility of
such simple treatments as aeration or limestone contactors, and also the cost associated with
chemical additions and chemical delivery systems. Having good calcium, magnesium,
sulfate, iron, manganese, and other water quality data may help in defining constraints to
pH adjustment, phosphate dosing, use of packed tower aerators, membranes or other
processes, because of scale buildup issues. Knowing whether or not arsenic or radon are
present in the source water will dictate corrosion control treatments which are compatible
with the removal processes, and this can be planned and done at once. For example, radon
can readily be removed by aeration, which can also be used for substantial pH adjustment
for corrosion control, so chemical feeds may not be necessary. However, a complication to
both might be the presence of iron or manganese, so a combination of a removal process or
filtration following oxidation (aeration/disinfection) might be cost-effective and would
eliminate the need for sequestration. Similarly, some arsenic removal processes may
coincide with iron removal and simplify the corrosion control chemistry treatment. For
surface water or blended surface/ground water systems, knowledge of the potential for
disinfection byproduct formation or microbial concerns could change the corrosion control
approach. There are many other possible interactions, and the water system should try to
anticipate as many future regulatory water quality requirements and treatment selection
influences as possible.
Step 3: Once accurate water quality data are known, a) look up the DIG of your water in
Table 3 on pages 13 -17 based on raw water pH and alkalinity; b) Determine the
highest pH that you can achieve with your water without creating scaling conditions
using your hardness data and Figure 1 on page 18; and c) Use one of the five
attached sets of treatment recommendation flow chart sheets to select treatment
options (see Section 1). The treatment recommendation flow charts suggest appropriate
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water quality modifications based on the limited amount of water quality information
available to the water system. Treatment strategies not suggested by the flow charts for a
particular set of water quality characteristics should be avoided.
Increasing the pH of a water that contains calcium may promote the precipitation of
calcium carbonate. In some circumstances, precipitation of calcium carbonate can clog hot
water heaters and produce cloudy water. To limit the problems associated with calcium
precipitation, the pH at which calcium is likely to precipitate can be estimated by use of
Figure 1. The pH of calcium precipitation is estimated by finding the point on the figure
that corresponds to the DIG and calcium level. The calcium must be expressed as calcium
(Ca) and not calcium carbonate (CaCO3). Note that maintaining the pH below the level
estimated on the chart should minimize, not eliminate, the potential for precipitating
calcium carbonate. In many cases, it will be possible to exceed the estimated pH levels
without having a calcium precipitation problem because the precipitation of calcium is
affected by many factors, such as temperature and other dissolved metals.
Step 4: Once the treatment option(s) are selected from the treatment recommendation flow
charts, use the "Water Treatment Considerations" (see Section 2) to determine if
there are other restricting factors. If all of the conditions are not met for a particular
treatment, then that strategy should be discarded.
Step 5: If there is more than one viable treatment option remaining, examine each option
with regard to secondary impacts, the operability of the system (see Section 3) and
costs. In some cases, several different treatment options will be available to a particular
water supply. As a result, some water systems will be able to select the most appropriate
treatment option based on system configuration, economics, simplicity, reliability,
operations, and other site-specific factors. Consideration will also need to be given to
impacts of drinking water treatment chemicals on wastewater discharge limits, or
concentrations of metals in sludge.
As EPA has moved toward water quality-based limits for wastewater treatment plant
effluents since 1994, permissible levels of many of the metals in effluents have been reduced
to well below the drinking water standards. Example water quality based effluents for
copper, lead, and zinc are listed in Table 1 with the drinking water standards for these
metals presented for contrast. The range in limits permitted for these metals are based on
the designated use for the receiving water and the total hardness of the receiving water.
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Table 1: Metals Limits in Drinking Water and Wastewater Effluents*
Metal
Copper
Lead
Zinc
Drinking Water
Limit (jjg/L)
1,300
15
5,000
Wastewater Limit
(Mg/L)
6.4 - 65
1.3 - 956
59 - 758
*From NPDES Permit Writers Manual, 1996
Removal of metals from the waste water to the sludge does provide some way to reduce metals in the
wastewater effluent but, depending on the final residual (sludge) disposal method, there are limits for
metals in sludges also. Land applied residuals must meet the pollutant concentration limits outlined in
Table 2.
Table 2: Metals Limits in Land Residual*
Metal
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Zinc
Pollutant Concentration Limit
(mg/kg)
41
39
1,200
1,500
300
17
420
36
2,800
*From A Plain English Guide to Part 503 Rule, 1994
Thus, many wastewater utilities have found that preventing metals from getting into the wastewater
stream has proven more cost-effective than trying to remove them. Some wastewater utilities have
gone so far as to provide some of the funding to their water utility to support corrosion control efforts
rather than construct improved metals removal treatment at the wastewater treatment plant.
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Another consideration for wastewater treatment plants is nutrient limits in wastewater effluents.
Nutrients are nitrogen and phosphates in the wastewater effluents that can promote overgrowth of
algae or aquatic plants in receiving waters. On the other hand, phosphate inhibitor addition can be a
significant benefit for corrosion control for water utilities.
Detailed discussion of all aspects pertinent to selection of optimal corrosion control are beyond the
scope of this document, but should be thoroughly addressed by all water systems as appropriate.
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Section 1 Flow Chart Treatment Determinations
At the end of this section, the user will find five sets of flow charts that can be used to determine
treatment approaches depending on whether the system has exceeded the lead action level, the copper
action level or both and whether the system treats for iron/manganese removal. Select the set that
corresponds to your system as follows:
1. Exceeded lead and copper action level - sheets 1A, 2A, 3A
2. Exceeded lead action level - sheets IB, 2B, 3B
3. Exceeded copper action level - sheets 1C, 2C, 3C
4. Exceeded either of the action levels, have elevated source water iron and manganese levels,
and iron and manganese removal treatment sheets ID and 2D
5. Exceeded either of the action levels, have elevated source water iron and manganese but do
not have iron/manganese removal treatment sheets IE and 2E.
Before using the flow charts, you will need to read the following information and calculate the
DIG and highest treatment pH value for your water hardness as described below. The selection
of a corrosion control treatment option will be dependent on the pH, alkalinity, DIG, and other water
quality data such as calcium, iron, and manganese. Invalid water quality data can result in the
misapplication of a treatment strategy. Note that as treatments are applied, particularly pH adjustment,
your position and choices may move to another chart. Note also that the presence of iron or
manganese removal treatment alters the proposed corrosion control treatment for those systems with
iron and/or manganese in the raw water. At higher pH values, both iron and manganese oxidation
rates rise dramatically, with the potential to improve removal of these metals if the pH is raised before
the filtration step.
pH Measurements field pH is the most critical variable for determining treatment options.
Many factors affect pH measurements. The following are some of the most significant.
1. The pH instrumentation and calibration. Many pH-measuring devices do not allow for
appropriate calibration. Calibration of the pH probe should be performed with 3 standards
at pH = 4, pH =7, and pH= 10. Calibration should also be performed prior to each set of
analyses.
2. Aeration of the sample. Loss or introduction of carbon dioxide can greatly affect the pH
of the sample, almost immediately. The pH should be measured on-site (in the field) with
extreme care being taken not to shake the sample, stir rapidly, or to expose the water to the
atmosphere if it can be avoided. The use of small flasks and rubber stoppers bored out and
fit around electrodes have been found to be very useful for minimizing the substantial
errors that can result in pH from only a few minutes of contact of ground waters with
excess carbon dioxide or pH adjusted waters with the air. (See: "Laboratory Techniques for
Measurement of pH for Corrosion Control Studies and Water not in Equilibrium with the
Atmosphere." Jour. AWWA, 72:5:304, 1980).
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3. Water Quality Variations. pH may vary depending upon the time of day, the season, or in
response to precipitation. For well supplies, the pH may vary depending on how long the
pump has been running. It is critical to examine when the samples were collected and over
what time period. If the water source varies seasonally as a function of precipitation or
temperature it would be important to have data over the period of the entire seasonal cycle.
Alkalinity The laboratory that performs the alkalinity analysis should report the data in the
form "mg/L as CaCO3".
DIG Calculation - DIG affects levels of lead and copper levels and plays an important role in
stabilizing pH. The DIG is calculated by using Table 3, which was developed with good
approximations for many water conditions. Determine the DIG by reading corresponding pH
and alkalinity values measured by the water system.
Once the DIG has been determined, calculate the highest pH that can be achieved with your
particular water given the hardness of the water.
Hardness As pH is raised, calcium and magnesium compounds become less soluble and can
scale. Determine the highest pH that can be achieved with your water using Figure 1 on page
18 by placing a horizontal line at your calcium level (i.e., hardness value divided by 2.5) and a
vertical line at your DIG value. The point at which the two lines cross is the pH value at which
scaling can occur. If the point is between two pH values, the lower pH value would be most
conservative to use.
The treatment sheets begin on page 19. They are presented as described in the beginning of this
section. The suggested treatment chemicals are listed in the order of most appropriate for most
systems, with alternates or more complex options listed below. For example, in Sheet 1A, for systems
that exceeded the lead action level and have DIG of <5 mg C/L, soda ash is the pH adjustment
chemical that would be the most widely applicable treatment chemical, though all the other options
should be reviewed to see which may be the most cost effective.
Revised Guidance Manual for
SelectingLead and Copper ControlStrategies 12 March 2003
-------
Table 3: Dissolved Inorganic Carbonate Determination (DIG mg C/L)
for Systems with pH of 4.6 to 7.4 and Alkalinities of 0 to 100
For a Purely Carbonate+H2O Closed System at 10°C (50°F); Ionic Strength = 0.005 (TDS @ 200 or Cond. @ 312)
Alpha
H2CO3*
Alpha
HC03-
Alpha
CO3=
PH
0.98
0.02
0.00
4.6
0.97
0.03
0.00
4.8
0.96
0.04
0.00
J.O
Alkalinity (as CaCO3)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
19
93
167
241
316
390
464
539
613
687
761
836
910
984
1058
1133
1207
1281
1355
1430
1504
8
55
102
149
197
244
291
339
386
433
480
528
575
622
670
717
764
812
859
906
953
3
33
64
94
124
154
185
215
245
276
306
336
366
397
427
457
488
518
548
578
609
0.94
0.06
0.00
J.2
1
21
40
60
79
99
119
138
158
177
197
216
236
255
275
295
314
334
353
373
392
0.91
0.09
0.00
J.4
1
13
26
39
52
64
77
90
103
116
128
141
154
167
179
192
205
218
231
243
256
0.86
0.14
0.00
J.6
0
9
17
26
34
43
51
60
68
77
85
94
102
111
119
128
136
145
153
162
170
0.79
0.21
0.00
J.8
0
6
12
18
23
29
35
41
47
52
58
64
70
76
81
87
93
99
105
110
116
0.71
0.29
0.00
6.0
0
4
8
12
16
21
25
29
33
37
41
45
49
53
58
62
66
70
74
78
82
0.60
0.40
0.00
6.2
0
3
6
9
12
15
18
21
24
27
30
33
36
39
43
46
49
52
55
58
61
0.49
0.51
0.00
6.4
0
2
5
7
9
12
14
17
19
21
24
26
28
31
33
35
38
40
42
45
47
0.38
0.62
0.00
6.6
0
2
4
6
8
10
12
14
15
17
19
21
23
25
27
29
31
33
35
37
39
0.28
0.72
0.00
6.8
0
2
o
J
5
7
8
10
12
13
15
17
18
20
22
23
25
27
28
30
32
o o
JJ
0.20
0.80
0.00
7.0
0
1
3
4
6
7
9
10
12
13
15
16
18
19
21
22
24
25
27
28
30
0.13
0.87
0.00
7.2
0
1
o
J
4
6
7
8
10
11
12
14
15
17
18
19
21
22
24
25
26
28
0.09
0.91
0.00
7.4
0
1
o
J
4
5
7
8
9
11
12
13
14
16
17
18
20
21
22
24
25
26
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
13
March 2003
-------
Table 3: Dissolved Inorganic Carbonate Determination (DIG mg C/L)
for Systems with pH of 4.6 to 7.4 and Alkalinities of 110 to 400
For a Purely Carbonate+H2O Closed System at 10°C (50°F); Ionic Strength = 0.005 (TDS @ 200 or Cond. @ 312)
Alpha
H2CO3*
Alpha
HCO3-
Alpha
CO3=
PH
0.98
0.02
0.00
4.6
0.97
0.03
0.00
4.8
0.96
0.04
0.00
/
0.94
0.06
0.00
/.2
Alkalinity (as CaCO3)
110
120
130
140
150
160
170
180
190
200
220
240
260
280
300
320
340
360
380
400
1652
1801
1949
2098
2247
2395
2544
2692
2841
2989
3319
3619
3919
4219
4519
4819
5119
5419
5719
6019
1048
1143
1237
1332
1426
1521
1616
1710
1805
1899
2130
2312
2504
2696
2888
3080
3272
3464
3656
3848
669
730
790
851
912
972
1033
1093
1154
1214
1323
1443
1563
1683
1803
1923
2043
2163
2283
2403
431
470
510
549
588
627
666
705
744
783
881
961
1041
1121
1201
1281
1361
1441
1521
1601
0.91
0.09
0.00
L4
282
307
333
358
384
409
435
461
486
512
587
641
694
747
801
854
907
961
1014
1067
0.86
0.14
0.00
S.6
187
204
221
238
255
272
289
306
323
340
377
412
446
480
515
549
583
617
652
686
0.79
0.21
0.00
J.8
128
140
151
163
174
186
198
209
221
232
264
288
312
336
360
384
408
432
456
480
0.71
0.29
0.00
6
90
99
107
115
123
132
140
148
156
164
185
202
219
236
253
270
286
303
320
337
0.60
0.40
0.00
6.2
67
73
79
85
91
97
103
109
115
121
135
148
160
172
185
197
209
222
234
246
0.49
0.51
0.00
6.4
52
57
61
66
71
75
80
85
90
94
108
118
127
137
147
157
167
176
186
196
0.38
0.62
0.00
6.6
42
46
50
54
58
62
66
69
73
77
85
93
101
108
116
124
132
139
147
155
0.28
0.72
0.00
6.8
37
40
43
46
50
53
56
60
63
66
73
80
87
93
100
107
113
120
127
133
0.20
0.80
0.00
7.0
33
36
39
42
45
48
51
54
57
60
66
72
78
84
90
96
102
108
114
120
0.13
0.87
0.00
7.2
30
33
36
39
41
44
47
50
53
55
61
67
73
78
84
89
95
100
106
112
0.09
0.91
0.00
7.4
29
32
34
37
39
42
45
47
50
53
58
63
68
74
79
84
90
95
100
105
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
14
March 2003
-------
Table 3: Dissolved Inorganic Carbonate Determination (DIG nig C/L)
for Systems with pH of 7.6 to 10.4 and Alkalinities of 0 to 100
For a Purely Carbonate+H2O Closed System at 10°C (50°F); Ionic Strength = 0.005 (TDS @ 200 or Cond. @ 312)
Alpha
H2CO3*
Alpha
HCO3-
Alpha
C03=
PH
0.06
0.94
0.00
7.6
0.04
0.96
0.00
7.8
0.02
0.97
0.00
8
\lkalinity (as CaCO3)
3
5
LO
L5
20
25
50
55
10
15
50
55
SO
55
70
75
50
35
?0
?5
LOO
0
1
o
J
4
5
6
8
9
10
11
13
14
15
17
18
19
20
22
23
24
25
0
1
2
4
5
6
7
9
10
11
12
14
15
16
17
19
20
21
22
24
25
0
1
2
4
5
6
7
9
10
11
12
13
15
16
17
18
20
21
22
23
24
0.01
0.98
0.01
8.2
0
1
2
4
5
6
7
8
10
11
12
13
15
16
17
18
19
21
22
23
24
0.01
0.98
0.01
8.4
0
1
2
4
5
6
7
8
10
11
12
13
14
16
17
18
19
20
22
23
24
0.01
0.98
0.02
8.6
0
1
2
4
5
6
7
8
9
11
12
13
14
15
17
18
19
20
21
23
24
0.00
0.97
0.03
8.8
0
1
2
3
5
6
7
8
9
11
12
13
14
15
16
18
19
20
21
22
23
0.00
0.95
0.04
9
0
1
2
3
5
6
7
8
9
10
11
13
14
15
16
17
18
20
21
22
23
0.00
0.93
0.07
9.2
0
1
2
3
4
6
7
8
9
10
11
12
13
15
16
17
18
19
20
21
22
0.00
0.90
0.10
9.4
0
1
2
3
4
5
6
8
9
10
11
12
13
14
15
16
17
18
19
21
22
0.00
0.84
0.16
9.6
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
18
19
20
21
0.00
0.77
0.23
9.8
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
14
15
16
17
18
19
0.00
0.68
0.32
10
0
1
2
2
o
J
4
5
6
7
8
9
10
11
12
12
13
14
15
16
17
18
0.00
0.58
0.42
10.2
0
0
1
2
o
J
4
5
5
6
7
8
9
10
11
11
12
13
14
15
16
16
0.00
0.46
0.54
10.4
-1
0
1
2
2
3
4
5
6
6
7
8
9
9
10
11
12
13
13
14
15
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
15
March 2003
-------
Table 3: Dissolved Inorganic Carbonate Determination (DIG mg C/L)
for Systems with pH of 7.6 to 10.4 and Alkalinities of 110 to 400
For a Purely Carbonate+H2O Closed System at 10°C (50°F); Ionic Strength = 0.005 (TDS @ 200 or Cond. @ 312)
Alpha
H2CO3*
Alpha
HC03-
Alpha
CO3=
PH
0.06
0.94
0.00
7.6
0.04
0.96
0.00
7.8
0.02
0.97
0.00
8
0.01
0.98
0.01
8.2
Alkalinity (as CaCO3)
110
120
130
140
150
160
170
180
190
200
220
240
260
280
300
320
340
360
380
400
28
30
33
36
38
41
43
46
48
51
55
60
65
70
75
81
86
91
96
101
27
30
32
35
37
40
42
45
47
50
54
59
64
69
74
79
84
89
93
98
27
29
32
34
37
39
42
44
46
49
54
59
63
68
73
78
83
88
93
98
27
29
31
34
36
39
41
44
46
48
53
58
63
68
73
77
82
87
92
97
0.01
0.98
0.01
8.4
26
29
31
34
36
38
41
43
46
48
53
58
62
67
72
77
82
86
91
96
0.01
0.98
0.02
8.6
26
28
31
33
36
38
40
43
45
47
52
56
61
66
71
75
80
85
89
94
0.00
0.97
0.03
8.8
26
28
30
33
35
37
40
42
44
47
51
56
61
65
70
75
79
84
89
93
0.00
0.95
0.04
9
25
28
30
32
35
37
39
41
44
46
51
56
61
65
70
75
79
84
89
93
0.00
0.93
0.07
9.2
25
27
29
31
34
36
38
40
43
45
49
54
58
63
67
72
76
81
85
90
0.00
0.90
0.10
9.4
24
26
28
30
33
35
37
39
41
43
48
52
57
61
65
70
74
78
83
87
0.00
0.84
0.16
9.6
23
25
27
29
31
33
35
37
39
41
45
50
54
58
62
66
70
74
78
83
0.00
0.77
0.23
9.8
21
23
25
27
29
31
33
35
37
39
43
47
51
54
58
62
66
70
74
78
0.00
0.68
0.32
10
20
22
23
25
27
29
31
33
34
36
40
43
47
51
54
58
62
65
69
72
0.00
0.58
0.42
10.2
18
20
21
23
25
27
28
30
32
33
37
40
43
47
50
54
57
60
64
67
0.00
0.46
0.54
10.4
16
18
20
21
23
24
26
27
29
31
34
37
40
43
46
49
52
55
59
62
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
16
March 2003
-------
Table 3 Footnotes
Constants For DIG Calculations at 10°C
"A"-Davies' Single Ion Activity
Constant
Activity Correct Factors
Equilibrium Constants
DIG (mg/L as C) =
TEMP Farenheight
TEMP Centigrade
TEMP Kelvin
TDS mg/L
CONDUCT
ION STRENGTH
log fO- undissoc./no charge
log fm-monovalent
log fd-divalent
log Kw (Temp. Corrected)
log K'w (Ion Strength Corrected)
log Kl (Temp. Corrected)
log K'l (Ion Strength Corrected)
log K2 (Temp. Corrected)
log K'2 (Ion Strength Corrected)
49.986
10.0
283.15
200.0
312.0
0.0050
0.4976
0.0005
-0.0392
-0.1522
-14.5332
-14.4548
-6.4633
-6.3845
-10.4879
-10.3357
[(ALK(mg/L CaC03)/50044(mg CaCO3/equiv.) - K'w /{H} + {H})]
x [l/(alpha HC03 + Z(alpha CO3))]
x 12011 (mgC/mole)
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
17
March 2003
-------
Figure 1: Saturation pH for Calcium Carbonate Precipitation
25 50 75 100 125 150 175. 200
mg C/L DIG
\
\
\
0 5 10 15 20 25 30 35 40 45 50
mg C/L DIG
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
18
March 2003
-------
Sheet 1A: Exceeded Lead and Copper Action Levels
no
Goto
Sheet2A
>
V 1ST
^v Dl
<5
mgC/L
f >
Raise the pH in
0.5 unit increments &
DICto5-10mgC/L
using:
Soda ash
or
Potassium carbonate
("potash")
or
Caustic &
Sodium bicarbonate
or
Limestone contactor
ne s
5-15
mgC/L
t >
Raise the pH in
0.5 unit increments
using:
Soda ash
or
Potash
or
Caustic
or
Aeration
mgC/L
f
Raise the pH in
0.25 unit increments
using:
Aeration
or
Caustic
or
Soda ash
or
Potash
Orthophosphate addition
with pH/alkalinity adjustment at
pH 7.2 - 7.8 is an alternative
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
19
March 2003
-------
Sheet 2A: Exceeded Lead and Copper Action Levels
<5
mgC/L
Raise the pH in
0.5 unit increments &
DICto5-10mgC/L
using:
Soda ash
or
Potassium carbonate
("potash")
or
CausticS
Sodium bicarbonate
or
Limestone contactor
no
>,
Goto
Sheet 3A
±_ j
5-25
mgC/L
1) Raise the pH in
0.3 unit increments
using:
Caustic
or
Soda ash
or
Potash
OR
2)AddOrthophosphate*
>25
mgC/L
Add Orthophosphate*
or
Blended phosphate*
* Initial dose should be > 0.5 mg/L Orthophosphate as P either Orthophosphate or blend.
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
20
March 2003
-------
Sheet 3A: Exceeded Lead and Copper Action Levels
yes
no
<5
mgC/L
Raise the DIG to
5-10mgC/L
using:
Sodium bicarbonate
or
Soda ash
or
Potassium carbonate
("potash")
>5
mgC/L
Raise the pH in
0.3 unit increments
toward 9-9.5
using Caustic
yes
Raise the DIG to
5-10mgC/L
using
Sodium bicarbonate
no
Existing treatment
may be optimal
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
21
March 2003
-------
Sheet IB: Exceeded Lead Action Level Only
no
Goto
Sheet2B
<5
mgC/L
5-12
mgC/L
mgC/L
Raise the pH in
0.5 unit increments &
DICto5-10mgC/L
using:
Soda ash
or
Potassium carbonate
("potash")
or
Caustic &
Sodium bicarbonate
or
Limestone contactor
Raise the pH in
0.5 unit increments
using:
Soda ash
or
Potash
or
Caustic
or
Limestone Contactor
Raise the pH in
0.25 unit increments
using:
Aeration
or
Caustic
or
Potash
Orthophosphate addition
with pH/alkalinity adjustment at
pH 7.2 - 7.8 is an alternative
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
22
March 2003
-------
Sheet 2B: Exceeded Lead Action Level Only
no
Goto
Sheet3B
<5
mg C/L
5-25
mgC/L
>25
mg C/L
Raise the pH in
0.5 unit increments &
DIG to 5-10 mg C/L
using:
Soda ash
or
Potassium carbonate
("potash")
or
Caustic &
Sodium bicarbonate
or
Limestone contactor
1) Raise the pH in
0.3 unit increments
using:
Caustic
or
Soda ash
or
Potash
OR
2) Add Orthophosphate*
Add Orthophosphate*
or
Blended Phosphate*
* Initial dose should be > 0.5 mg/L Orthophosphate as P either Orthophosphate or blend.
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
23
March 2003
-------
Sheet 3B: Exceeded Lead Action Level Only
y-s
no
<5
mgQL
Raise the DCto
5-10mgQL&
pH to fusing:
Sodium bicarbonate
ancVor
Soda ash
or
Fbtassium carbonate
("potash")
>5
mgQL
Raise the pH in
0.3 unit increments
toward 9-9.5
using Caustic
Raise the DCto
5-10mg C^-
using
Sodium bicarbonate
no
Existing treatrrent
may be optimal
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
24
March 2003
-------
Sheet 1C: Exceeded Copper Action Level Only
no
Goto
Sheet 2C
>
<5 5-12
mg C/L mg C/L
1 \
Raise the pH in
0.5 unit increments &
DIG to 5- 10 mg C/L
using:
Soda ash
or
Potassium carbonate
("potash")
or
Caustic &
Sodium bicarbonate
or
Limestone contactor
':._
v is me ;
N. DIG? /
1 \
Raise the pH in
0.5 unit increments
using:
Soda ash
or
Potash
c
r
Caustic
or
Aeration
13-35
mgC/L
t >
Raise the pH in
0.3 unit increments
using:
Aeration
or
Caustic
c
r
Potassium
hydroxide
"
>35
mgC/L
i
Raise the pH to
7.2-7.8
Using:
Aeration,
and
Orthophosphate*
or
Blended phosphate*
Initial dose > 0.5 mg/L
Orthophosphate as P
Orthophosphate addition
with pH/alkalinity adjustment at
pH 7.2 - 7.8 is an alternative
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
25
March 2003
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Sheet 2C: Exceeded Copper Action Level Only
<5
mgC/L
Raise the pH in
0.5 unit increments &
DICto5-10mgC/L
using:
Soda ash
or
Potassium carbonate
("potash")
or
Caustic &
Sodium bicarbonate
or
Limestone contactor
no
5-25
mgC/L
1) Raise the pH in
0.3 unit increments
using:
Caustic
or
Soda ash
or
Potash
OR
2) Add Orthophosphate*
Goto
Sheet3C
>25
mgC/L
Add Orthophosphate*
or
Blended phosphate*
: Initial dose should be > 0.5 mg/L orthophosphate as P either orthophosphate or blend.
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
26
March 2003
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Sheet 3C: Exceeded Copper Action Level Only
<5
mgC/L
Raise the pH in
0.3 unit increments &
DICto5-10mgC/Lusing:
Soda ash
or
Potassium carbonate
("potash")
or
Caustic &
Sodium bicarbonate
The pH is > 7.8
(from Sheet 2C)
> 5
mgC/L
Add Orthophosphate*
or
Blended phosphate*
* Initial dose should be > 0.5 mg/L Orthophosphate as P either Orthophosphate or blend.
Revised Guidance Manual for
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27
March 2003
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Sheet ID: Exceeded Lead and/or Copper Action Levels
and Have Raw Water Iron or Manganese
<5
mgC/L
Do you
remove iron or
manganese?
5-12
mgC/L
Raise the pH in
0.5 unit increments &
DICto5-10mgC/L
(see Sheet 1A)
Raise the pH
In 0.5 unit increments
using:
Aeration*
or
Caustic
or
Sodium silicate
^Optimize aeration for pH increase
as well as iron oxidation
no
Goto
Sheet 1E
no
Goto
Sheet 2D
mgC/L
Raise the pH
In 0.25 increments
(see Sheet 1A for systems
withDIO15mg/LC/L)
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
28
March 2003
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Sheet 2D: Exceeded Lead and/or Copper Action Levels
and Have Raw Water Iron or Manganese
Iron or
manganese removal
The pH is > 7.2
(from Sheet 1D)
<5
mgC/L
5-20
mgC/L
>20
mgC/L
Raise the DIG
to5-10mgC/L
using:
Sodium bicarbonate
or
Sodium silicate
See Sheet 2A
for 5 - 25 mg C/L
Add blended phosphate*
*The blend should provide a minimum of 0.5 mg/L orthophosphate as P.
Revised Guidance Manual for
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29
March 2003
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Sheet IE: Exceeded Lead and/or Copper Action Levels
and Have Raw Water Iron or Manganese
No iron or
manganese removal
(from Sheet 1D)
no
Goto
Sheet 2E
>
<5
mgC/L
Raise the pH in
0.5 unit increments &
DICto5-10mgC/L
using:
Soda ash
or
Sodium bicarbonate &
Silicates
>
/
\
\N\
ist
Dl
\
5-12
mgC/L
Raise the pH
to 7.5
using:
Caustic
or
Soda ash &
Blended phosphate*
or
Silicates
lat
he
3?
/
\
/
>
12-25
mgC/L
Raise the pH
to 7.2 -7.5
using Caustic
AND
Add Blended phosphate*
>
>25
mgC/L
Raise the pH to
7.0-7.2
using Caustic &
Blended phosphate*
*The blend should provide a minimum of 0.5 mg/L orthophosphate as P.
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
30
March 2003
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Sheet 2E: Exceeded Lead and/or Copper Action Levels
and Have Raw Water Iron or Manganese
No iron or
manganese removal
(from Sheet 1D)
<5
mgC/L
Raise the DIG
to5-10mgC/L
using:
Sodium silicate
or
Sodium bicarbonate &
Blended phosphate*
>5
mgC/L
Add blended phosphate*
*The blend should provide a minimum of 0.5 mg/L orthophosphate as P.
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
31
March 2003
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Section 2 Water Treatment Considerations
For some water systems, more than one corrosion control treatment option may be chemically viable. The
purpose of this section is to provide information regarding specific treatment criteria, operation, and
secondary impacts associated with each treatment option which may further influence which final treatment
option should be chosen for your water system.
After identifying possible appropriate treatment strategies using the flow charts in Section 1, Water
Treatment Considerations should be reviewed to obtain more information about potential strategies. The
increases in pH, orthophosphate, or silicate concentration necessary for lead and copper control may
sometimes result in scaling in distribution system valves, in hot water heaters, or in some industrial chemical
processes, thus the need to determine the maximum pH feasible for the water to be treated. The criteria
listed under each specific treatment method must be met in order for that treatment to be selected.
pH Adjustment Systems - Caustic (sodium or potassium hydroxide), soda ash, limestone contactors (calcite
filters) and aeration (air stripping) are the principal methods for increasing the pH. Soda ash, potash, and
limestone contactors also increase DIC while aeration decreases DIC in the process of increasing pH.
Caustic (Sodium or Potassium Hydroxide) - Caustic, a liquid chemical, is very hazardous if not
handled carefully. It can cause severe burns and damage the eyes. Caustic feed systems at a
minimum should include an eye washing system, full shower, eye goggles, protective gloves, boots,
aprons, easy-to-handle barrels and chemical containment areas. For very small systems (e.g., schools,
trailer parks), a safer option such as soda ash should be used if possible. While caustic traditionally
means "sodium hydroxide" solution, potassium hydroxide can always be substituted for sodium
hydroxide if a water system prefers, and dosages adjusted accordingly. Sodium hydroxide may be
obtained as 25% or 50% solutions while potassium hydroxide is available as a 45% solution.
To use this treatment, a water system should have: Raa> water DIC > 5 mg C/L or the potential for severe pH swing
or overfeed is great. Note: A small change (+1 mg/L) in caustic dosage can result in pH variations of up
to 2 pH units, a 100-fold change in hydrogen ion concentration. Effective corrosion control requires
stable pH values so, for water systems with low DICs, an alternate means of pH adjustment should
be used.
Soda Ash/Potash - Soda ash, or sodium carbonate, and potassium carbonate ("potash") are dry
compounds which are relatively safe to handle compared to caustic. These carbonate chemicals will
not cause skin irritation. When soda ash or potassium carbonate is added to a water, there is an
increase in DIC as well as pH. Because soda ash and potassium carbonate are safe to handle, they are
strongly recommended as the pH adjustment chemical for schools, condominiums, or any facility
where technical resources are limited. They dissolve more easily than lime. Potassium carbonate is
more expensive than soda ash but is more soluble and easier to handle, so many very small water
systems have found it the best choice for pH/alkalinity adjustment.
To use this treatment, a water system should have: Raa> Water DIC levels that are higher than 2 mg C/L but lower
25 mg C/L.
Revised Guidance Manual for
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Aeration Systems - Aeration systems can increase the pH of groundwater systems or stratified surface
water systems by removing over-saturated carbon dioxide. A stratified surface water is one that
creates different density and water quality layers as a result of temperature changes over the summer
season. The bottom layers often lose dissolved oxygen and have elevated levels of carbon dioxide,
iron, and manganese because the stratification prevents diffusion of dissolved oxygen from the upper
water to the lower. Aeration is the only pH adjustment method that does not add a chemical to the
water and the only one that can reduce excess DIG. Many groundwater systems have low to
moderate levels of alkalinity but low pH and high DIG values due to the presence of carbon dioxide
at levels exceeding saturation values. A water system can test for excess carbon dioxide by testing for
pH carefully at the source, collecting a sample and letting it sit in open air while stirring to allow the
carbon dioxide to escape and then, after 10-15 minutes of mixing, re-testing the pH. There are a
wide variety of pH adjustment systems including diffused bubble systems, packed or tray tower, and
venturi systems. Any aeration system selected for pH adjustment should be capable of removing at
least 80 - 90% of the carbon dioxide. Larger amounts of pH adjustment will require the use of
designs that produce higher percentages of carbon dioxide removal. One of the disadvantages
associated with aeration is that re-pumping of the water is required. Some water systems can
configure their well, plant, and storage locations to maximize the use of gravity in the hydraulics of
their distribution networks. Some State regulatory agencies require systems to disinfect the water
after aeration so that any microbes introduced during aeration will not grow out in the distribution
system.
To use this treatment, a water system should have: Groundwater source or stratified surface water source. See aeration
feasibility tree Sheets 4A and 4B located on pages 34 and 35.
Limestone Contactors - A limestone contactor is usually an enclosed filter containing crushed high-
purity limestone (CaCO3). As the water passes through the limestone, the limestone dissolves, raising
the pH, calcium, alkalinity, and DIG of the water. Since the system does not require any pumps or
continuous addition of limestone, it is very simple and requires very little maintenance. Occasionally
the limestone must be replaced. The limestone is not a hazardous material. When obtaining a design
for a limestone contactor, it is important to ensure that it is adequately sized to produce sufficiently
high pHs for the range of flow rates and temperatures encountered during plant operation.
In Europe and the Middle East, limestone contactors have been designed to assist in iron removal
from groundwater as well as pH and alkalinity adjustment. These contactors have bypasses and the
capability for backwash to help remove some of the iron that accumulates on the limestone. The
most successful are operated in an up-flow rather than a down-flow mode. Flow rates for successful
iron removal with a limestone contactor are generally lower than typical flow rates for limestone
contactors used for pH and alkalinity adjustment only.
To use this treatment, a water system should have pH < 7.2, calcium < 60 mg/L,, and alkalinity < 100. See
Limestone Contactor Feasibility Tree Sheet 5A located on page 36.
Revised Guidance Manual for
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Sheet 4A: Aeration Feasibility Tree
groundwater
source
Is the
raw water
iron > 0.20 mg/L or
manganese > 0.05
mg/L?
Is hardness
unsaturated at the
target pH?
Is
radon > 400
pCi/L?
no
yes
no
no
yes
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies
Use another
corrosion control
treatment
1) Optimize aeration
for pH adjustment
and iron oxidation
or
2) Sequester metals
ahead of aeration
See Sheet4B
Aeration is not favored
unless softening or
hardness sequestering
is practical
Aeration is possible,
but radon removal
is not an incentive
Aeration is favored
34
March 2003
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Limits of Aeration
Sheet 4B
unsat4C
unsat 8C
unsat 12C
sat4C
Bsat 8C
sat 12 C
6.6
0 25 50 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425
alkalinity, mg/L as CaCO3
Revised Guidance Manual for
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35
March 2003
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Sheet 5A: Limestone Contactor Feasibility Tree
Use an alternate
pH/alkalinity
treatment method
Is the
pH < 7.2?
Is
calcium < 60
mg/L?
Is
iron < 0.20
mg/L?*
Iron and manganese
can coat limestone
contactor and slow calcium
carbonate dissolution,
Special contactor design required
Is
manganese
<0.05
mg/L?*
alkalinity < 100
mg/L as
CaCOS?
Limestone contactor
is feasible
Use DESCON
for design guidance
Revised Guidance Manual for
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36
March 2003
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Secondary Water Quality Impacts from pH/alkalinity adjustment - When the pH and alkalinity of a
water supply is increased, several unwanted side effects may occur. Water systems with a low pH (~7),
elevated levels of iron and manganese, and no process for iron and/or manganese removal at the source may
notice a significant increase in black and red water complaints when the pH is increased. Elevated pH
enhances the oxidation of both iron and manganese which is of benefit if the system removes these metals
but can be problematic if the system relies on sequestration to prevent red/black water incidents.
Further, increasing the pH of a water that contains calcium may promote the precipitation of calcium
carbonate. In some circumstances, precipitation of calcium carbonate can clog hot water heaters and
produce cloudy water. To limit the problems associated with calcium precipitation, the pH at which calcium
is likely to precipitate can be estimated by use of Figure 1. The pH of calcium precipitation is estimated by
finding the point on the figure that corresponds to the DIG and calcium level. The calcium needs to be
expressed as calcium (Ca) and not calcium carbonate (CaCO3). Note that maintaining the pH below the level
estimated on the chart should minimize, not eliminate the potential for precipitating calcium carbonate. In
many cases, it will be possible to exceed the estimated pH levels without having a calcium precipitation
problem because the precipitation of calcium is affected by many factors, such as temperature and other
dissolved metals.
Water systems using surface water are subject to a series of regulations under a broad heading of the
Microbial and Disinfection Byproducts Rules (MDPR). These systems must meet certain disinfection
criteria. This includes maintaining an adequate contact time with chlorine at a specific pH and temperature,
by meeting certain "CT" criteria, and other disinfection credits through filtration. A corrosion control
strategy that causes an increase in pH may affect your ability to maintain adequate chlorine contact. Increases
in finished water pH for surface water supplies should be performed after the chlorine contact chamber.
Disinfection byproduct (DBF) formation also varies with pH. There is a tendency for trihalomethanes
(THMs) to increase with prolonged exposure to higher pHs, whereas haloacetic acids tend to form or persist
at lower pH values. Depending on the points of chlorination and the DBF precursor material concentration
remaining after initial treatment, corrosion control strategies may be limited by concerns of violating
regulatory levels for DBFs in the distribution system.
DIG Adjustment Systems - The adjustment systems for DIG include aeration and soda ash/potash
(described above), and sodium bicarbonate (baking soda).
Sodium Bicarbonate - Sodium bicarbonate is a dry chemical that substantially increases the alkalinity and
DIG, while providing a very minimal increase in pH. This chemical is typically applied to waters with
very minimal DIG (< 5 mg C/L). Because it is a dry chemical, it must be dissolved in a tank of water for
feeding. It is very safe to handle and will not increase the pH above 8.3. Some utilities use both soda ash
or caustic and sodium bicarbonate together if a significant increase in pH and alkalinity are needed.
To use this treatment, a water system should have: DIC < 5 mg C/L.
Phosphate Addition - The addition of orthophosphate to a water supply can be achieved by adding any one
of several different formulations. These include zinc orthophosphate, potassium or sodium orthophosphate,
Revised Guidance Manual for
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-------
and phosphoric acid. Various chemical suppliers can furnish orthophosphate chemicals in liquid or dry
chemical forms. The goal is to ensure that an adequate dosage of orthophosphate is maintained throughout
the distribution system. Phosphoric acid is not recommended for small systems because it is a strong acid
that can be difficult to handle, as it is both a skin contact and inhalation hazard requiring stringent safety
procedures. Orthophosphate may also be added by dosing poly/orthophosphate blends, so the ratio of
orthophosphate to polyphosphate is very important to assure sufficient orthophosphate residual to control
the lead or copper release. Too much polyphosphate will cause instability of protective scales. The addition
of orthophosphate or blended phosphates may cause the temporary release of particles (turbidity) from the
inside surfaces of pipes. Over time, the conditions will stabilize and turbidity and color levels should return
to existing levels.
Orthophosphate - Orthophosphate formulations are available as phosphoric acid, sodium phosphate
compounds, or proprietary compounds that contain zinc or other special ingredients. The compounds
that contain zinc may promote problems with receiving wastewater treatment plants. Orthophosphate is
a nutrient, so many wastewater treatment plants are limited in the amount of orthophosphate they can
discharge to the receiving stream. It is important to check with the wastewater treatment plant to
establish proper limits for the phosphate dosage. If zinc is a problem, either a non-zinc based
orthophosphate or a high orthophosphate/low zinc product should be used. However, water systems
with soft water may find zinc as a very important additive to reduce the pH increases caused by contact
with cement and cement-lined pipes.
To use this treatment, a water system should have: pH in the range of 7.2-7.8 and DIC > 5 mg C/L. Note: When
substantial cement-lined or asbestos-cement pipe is present, formulations containing zinc are beneficial.
Blended Phosphates Blended phosphates contain some proportion of orthophosphate with the
remainder being a long-chain polyphosphate. The orthophosphate portion is most beneficial for
corrosion control while the polyphosphate sequesters hardness, iron, or manganese. As there are many
formulations, it is important to find what proportion of orthophosphate to polyphosphate works for
your water and specify a product that contains the correct proportion when it is delivered. Over time,
polyphosphates change to become orthophosphates so long term storage of the blended product,
particularly if it is a liquid, is not recommended.
To use this treatment, a water system should have: 1)pH 7.2-7.8; 2) DIC > 5 mg C/L; and 3) either iron or manganese
over secondary limits of 0.20 mg/L for iron and 0.05 mg/L for manganese or creating water quality problems (red or black
water), or hard water precipitation is a problem or a potential problem.
Secondary Water Quality Impacts from Phosphate Addition - When phosphates are added to a water
supply, several unwanted side effects may occur. There can be increased clogging of evaporative or injection
humidifiers; increased sludge buildup in hot water heaters; less clarity of ice cubes; and increased scaling or
algae growth in aquaria, fountains, and ornamental water bodies.
The fact that many of the phosphate-based products are proprietary makes it more difficult than with
commodity chemicals such as sodium hypochlorite or caustic, to evaluate the composition and amount of
phosphate in a particular product. Comparisons between products are not always clear from product
information sheets; often the Material Safety Data Sheets must be reviewed to determine phosphate type and
concentration.
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies 38 March 2003
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Silicates Silicates are mixtures of soda ash and silicon dioxide. Silicates can raise pH and have sequestering
capabilities, thus have been used by some utilities with low pH, low alkalinity water for corrosion control for
lead, copper and iron. The predominant mechanism is the rise in pH and DIG though the role of the silicate
hasn't been completely elucidated. Silicate has ability to sequester raw water iron and manganese if the levels
of these metals are not too high (> 1 mg/L combined). At least one system reported that, while the silicates
sequestered iron and manganese adequately, customers reported development of a tenacious white film on
glass shower doors and other glass surfaces in contact with hot water.
To use this treatment, a water system shouldhave pH < 7.2, DIC <10 mg C/L, andiron or manganese over secondary limits
or iron release in distribution system is a problem.
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies 39 March 2003
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Section 3 Optimizing Treatment
Once the best treatment strategy has been identified using the Flow Charts in Section 1, Water Treatment
Considerations in Section 2 and the appropriate operating pH has been determined, treatment can be
optimized. In addition, if orthophosphate is added, an appropriate distribution system orthophosphate
concentration needs to be maintained. No matter what the intended corrosion control strategy is, a
comprehensive flushing program should be started at least a few months before initiation of treatment
changes to remove sediment and loose scale material that could be easily re-suspended or destabilized by the
new treatment. Disinfection and microbial quality should be carefully monitored during the flushing period.
It is also important to continue the frequent and comprehensive flushing while the new treatment program is
stabilizing. The flushing will also aid in assuring delivery of the corrosion inhibitor or water of proper pH
and DIG levels to the surface of the pipes, which will help promote more rapid and more stable protective
film development on the pipes.
pH Adjustments - When using treatment chemicals including caustic (sodium or potassium hydroxide) or
soda ash (sodium or potassium carbonate), adjustments of pH should be made in 0.3 or 0.5 unit increments
as outlined on the sheets in Section 1. The pH should never be increased beyond 10. At a minimum, for
systems with a pH of less than 7.0, the pH should be increased to at least 7.0. For other pH increasing
systems, either aeration or limestone contactors, the final pH will be established by the specifics of
the water chemistry and design of the contactor or aerator.
Systems with unlined cast-iron pipe or large amounts of galvanized pipe need to consider the impacts of pH
adjustment on iron corrosion. Although, the water quality impacts that affect iron corrosion are poorly
understood, it appears that lower buffer intensity may accelerate iron corrosion. Water's minimal buffering
intensity occurs approximately in the pH range of 8.0 - 8.5. Water systems that move their pH into this range
may experience iron corrosion and red water. Lead and copper levels should be monitored at representative
homes or buildings four to six months after the pH has been adjusted. The State should then be consulted
to determine if another pH increase is needed. A decision to increase the pH should not be made before this
time because it usually takes at least four to six months and often longer in larger systems for lead and copper
levels to stabilize after a pH adjustment.
Orthophosphate Addition - The addition of orthophosphate should be performed by incremental increases
in the dosage. Orthophosphate should only be added when the_pH is in the range of 7.2-7.8. Initially a system
selecting orthophosphate should add enough of the orthophosphate-based chemical to establish at least a 1
mg PO4/L residual in the system. A close approximation is that 1 mg/L of orthophosphate expressed as P
corresponds to 3 mg/L expressed as PO4. Systems with high DIG and considerable new copper piping may
need to start with 3 mg PO4/L (1 mg/L as P) if possible. To establish this residual, the amount of
orthophosphate added will need to be higher than what is measured in the system since some of the
orthophosphate will be depleted. After establishing a residual of 1 mg PO4/L for 6 months, samples from
selected homes and buildings should be analyzed for lead and copper. The results should be discussed with
the State to determine if increasing the dosage is necessary to satisfy the "orthophosphate demand" of the
distribution system. If the local wastewater system can handle higher levels of phosphate, the dosage should
be increased in 1 mg PO4/L increments, with lead and copper monitoring following after 6 months with the
same dosage. The increases should continue until the desired metals levels are achieved. Even when lead
and copper levels are substantially reduced, dosages should not be lowered until the orthophosphate residual
throughout the distribution system is constant and is nearly equal to the concentration leaving the treatment
plant.
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies 40 March 2003
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Section 4 Example Treatment Determinations
Water System 1 - A typical New England Water System
Population: 2,000
Supply: single well
Status: system exceeded both lead and copper action level
pH Data: 6.7, 6.9, 6.4, 6.4, 6.7
Alkalinity: 56 and 45 mg CaCO3/L
Hardness: 45 mg/L as CaCO3
Calcium: 18 and 20 mg Ca/L
Step 1. Determine the DIC in mg C/L The median (mid-value pH) is 6.7 and the average alkalinity is 50.
Go to Table 3 and determine the DIC. Because there are no DIC values for a pH 6.7, determine the DIC at
a pH of 6.6 and a pH of 6.8 for an alkalinity value of 50, and average the two DIC results to determine the
DIC at pH 6.7.
For a pH of 6.6 and alkalinity of 50 the DIC is 19.
For a pH of 6.8 and alkalinity of 50 the DIC is 17.
For a pH of 6.7, the DIC would be approximately 18.
Step 2. Determine the maximum pH to minimise calcium precipitation Using Figure 1 with an average
calcium concentration of 19 mg/L and a DIC of 18, the maximum pH is about 8.3.
Step 3. Use flow charts The sheets for systems that exceeded both the lead and copper (set 1A) action
levels are used. The first sheet is used since the pH is less than 7.2. The DIC is greater than 12 mg C/L,
therefore the viable treatment options are: aeration, caustic, or soda ash or potash.
Step 4. Use the Water Treatment Considerations Check the requirements for each of the viable treatment
options. Because all the criteria listed under the three treatment options have been met, any of the three
treatment options may be selected. A study of the costs/benefits of each of the three methods should then
be undertaken to see which treatment is the least expensive and most able to meet other regulations (e.g.,
MDBP rules, Arsenic Rule, wastewater discharge requirements).
Revised Guidance Manual for
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Water System 2 A Midwestern Water System
Population: 100
Supply: single well
Status: system exceeded copper action level
pH Data: 6.9, 7.2, 7.1, 7.0, 7.0
Alkalinity: 300 and 330 mg/L as CaCO3
Hardness: 280 mg/L as CaCO3
Calcium: estimated at 112 mg Ca/L (280/2.5 = 112)
Step 1. Determine the DIC in mg C/L - The median (mid-value pH) is 7.0 and the average alkalinity is 315.
Go to Table 3 and determine the DIC. For a pH of 7.0 and alkalinity of 315, the DIC is 96 mg C/L.
Step 2. Determine the maximum pH to minimise calcium precipitation Using Figure 1 with a calcium
concentration of 112 mg/L and a DIC of 96 the maximum pH is about 6.95 so this water has tendencies to
scale at the ambient pH.
Step 3. Use flow charts The sheets for systems that exceeded the copper action level (set 1C) are to be
used. The first sheet is used since the pH is less than 7.2. The DIC is > 25 mg C/L, therefore the viable
treatment option is addition of blended phosphate to control scaling and help control copper corrosion along
with the minor addition of caustic to raise the pH to 7.2.
Step 4. Use the Water Treatment Considerations Check the requirements for the viable treatment option.
Because all the criteria listed under the treatment option has been met, with the exception of the presence of
iron and/or manganese, the next step is the selection of the most appropriate blended phosphate. Often the
State Lead and Copper Coordinator can provide some information about products that have worked for
systems with similar water quality. The product needs enough orthophosphate (0.5 mg/L minimum) to
provide corrosion control but enough polyphosphate to minimize scaling of the hardness in the system.
Revised Guidance Manual for
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Water System 3 A Western Water System
Population: 2,900
Supply: surface water and groundwater
Status: system exceeded both lead and copper action level
GROUNDWATER DATA SURFACE WATER DATA
20 % of supply 80% of Supply - 140,000 GPD
pHData: 7.6,7.4,7.6,7.5,7.6 pH data: Typically 6.8
Alkalinity: 60 to 75 mg CaCO3/L Alkalinity: 17 to 37 mg/L
Hardness: 90 to 95 mg/L as CaCO3
Calcium: 30 to 38 mg Ca/L Calcium: 10 mg Ca/L
Iron: 0.35 mg/L
Multiple Source System
Several factors must be examined when determining treatment for a water system with multiple sources.
1. Amount of Water. The surface water in this case is where most of the water is derived. It is of greater
importance on that basis.
2. Corrosiveness: The primary factors here are the pH and alkalinity. The groundwater, having higher pH
and alkalinity values, is less corrosive.
Based on these factors, the approach should be to determine a treatment recommendation for the surface
water supply.
Step 1. Determine the DIC in mg C/L For the surface water source, the median (mid-value) pH is 6.8 and
the average alkalinity is 27. Go to Table 3 and determine the DIC. For a pH of 6.8 and alkalinity of 30
(closest value to 27), the DIC is 10 mg C/L.
For the groundwater source, the median (mid-value) pH is 7.6, the average alkalinity is 68. From Table 3, the
DIC is 17 mg C/L.
Step 2. Determine the maximum pH to minimise calcium precipitation - Using Figure 1 with a calcium
concentration of 10 mg/L and a DIC of 10, the maximum pH is about 9.25.
Step 3. Use flow charts The sheets for systems that exceeded both the lead and copper action levels (Sheets
A) are to be used. Sheet 1A is used since the pH is less than 7.2. The DIC is 10 mg C/L, therefore the viable
treatment options for the surface water are: soda ash, potash, caustic, or limestone contactor. Aeration is
rejected because stratification is not a major observation for the surface water supply. A treatment
compatible with the groundwater quality would be beneficial so Sheet 2E is reviewed. This sheet is for a
groundwater source that exceeded lead and/or copper, have elevated iron with no iron removal, and have an
average pH greater than 7. Flowchart 2E lists blended phosphate addition as the best option. The surface
water pH and alkalinity would have to be raised in order to be in the correct range for blended phosphate
addition and to more closely match the pH and alkalinity of the groundwater.
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Step 4. Use the Water Treatment Considerations Check the requirements for each of the viable treatment
options. Soda ash or potash can be used because surface water system DIG falls within the required range of
2-25 mg C/L as outlined in the Water Treatment Considerations. Caustic is an option but should be looked
at carefully as the surface water alkalinity is quite variable and an overfeed could result in very high
distribution system pH values. A limestone contactor is an option. A cost-benefit study should be
conducted with the awareness that a higher pH water in the distribution system may affect iron oxidation
within the boundary area where the surface water meets the groundwater. Matching the pH and alkalinity of
the groundwater source may reduce adverse iron reactions.
Revised Guidance Manual for
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Section 5 Some Additional Sources of Information
Anderson, D.R., Row, D.D., and Sindelar, G.E., 1973. Iron and Manganese Studies of Nebraska Water
Supplies Jour. AWWA, 65:10:635.
AWWA (American Water Works Association), 1999. Water Quality and Treatment. R.D. Letterman (ed.).
McGraw-Hill, New York, NY.
AWWARF (American Water Works Association Research Foundation), 1990. Lead Control Strategies. AWWA
Research Foundation and AWWA, Denver, CO.
AWWARF (American Water Works Association Research Foundation), 1997. A. General Framework for
Corrosion Control Eased on Utility Experience. AWWA Research Foundation, Denver, CO.
AWWARF-TZW, 1996 (Second ed.). Internal Corrosion of Water Distribution Systems. AWWA Research
Foundation/DVGW Forschungsstelle-TZW, Denver, CO.
Cantor, A.F., Demg-Chakoff, D, Vela, R.R., Oleimk, M.G, Lynch, D.L., 2000. Use of Polyphosphate in
Corrosion Control. Jour. AWWA, 92:2:95.
Dodrill, DM. & Edwards, M., 1995. Corrosion Control on the Basis of Utility Experience. Jour. AWWA,
87:7:74.
Kettunen, R., and Keskitalo, P., 2000, Combination of membrane technology and limestone filtration to
control drinking water quality. Desalination 131 (2000) 271-283
Letterman, R.D., Driscoll, C.T., Haddad, M., and Hsu, H.A., 1986. Limestone Bed Contactors for Control of
Corrosion at Small Water Utilities, USEPA 600/S2-86/099
Letterman, R.D., Haddad, M. & Driscoll, C.T., Jr., 1991. Limestone Contactors: Steady State Design
Relationships. Jour. Envir. Engrg. Div.-ASCE, 117:3:339.
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. & Kathari, S., 1996. A Computer Program for the Design of Limestone Contactors. Jour.
NEWWA, 110:1:42.
Lytle, DA., Schock, M.R., Clement, J.A., and Spencer, C.M., 1998. Using Aeration for Corrosion Control.
Jour. AWWA, 90:3:74; Erratum. Jour. AWWA, 90:5:4 &Jour. AWWA, 90:9:4
New England Water Works Association and USEPA Region 1, 1993. Basic Chemistry and Corrosion Control
Water Treatment to Meet the SDWA Lead and Copper Rule: Reference Notes for Small Systems. New England Water
Works Association.
Rezania, Lih-In W, and Anderl, WH. Copper Corrosion and Iron Removal Plants Proc. National Conference on
Integrating Corrosion Control and Other Water Quality Goals, Cambridge, MA (1996)
Revised Guidance Manual for
Selecting Lead and Copper Control Strategies 45 March 2003
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Rezania, Lih-In W, and Anderl, WH. Corrosion Control for High DIG Groundwater: Phosphate or Bust.
Prvc. AWWA Annual Conference, Atlanta, GA (1997)
Rooklidge, S.J. and Ketchum Jr., L.H., 2002. Corrosion control enhancement from a dolomite-amended slow
sand filter. Water Research, 36(2002)2689-2694
Schock, M.R., 1999. Reasons for Corrosion Control other than the Lead and Copper Rule. Jour. NEWWA,
113:2:128.
Schock, M.R. & Clement, J.A., 1998. Control of Lead and Copper with Non-zinc Orthophosphate. Jour.
NEWWA, 112:1:20.
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, Proc. AWWA Water Quality
Technology Conference, Nov. 1-4, San Diego, CA.
Schock, M.R., Edwards, M., Powers, K., Hidmi, L., and Lytle, D.A., 2000. The Chemistry of New Copper
Plumbing, Proc. AWWA Water Quality Technology Conference, November 5-9, Salt Lake City, UT.
Schock, M.R., Lovejoy, T.R., Holldber, J., Lowry, J., and Egan, J., 1999. California's First Aeration Plants for
Corrosion Control, Proc. AWWA Water Quality Technology Conference, Oct. 31-Nov. 3, Tampa, FL.
Schock, M.R. & Fox, J.C., 2001. Solving Copper Corrosion Problems while Maintaining Lead Control in a
High Alkalinity Water Using Orthophosphate, Proc. American Water Works Association Annual Conference, June 3-
7, Washington, DC.
Smith, P.G, and Gaber, A., 1995. The Use of Limestone Bed Filtration for the Treatment of Ferruginous
Groundwater, Jour. CIWEM, 9, April, 192
Spencer, C.M. & Brown, WE., 1997. pH Monitoring to Determine Aeration Effectiveness for Carbon
Dioxide and Radon Removal, Proc. AWWA Water Quality Technology Conference, November 9-13, Denver, CO.
Spencer, C.M., 1998. Aeration and Limestone Contact for Radon Removal and Corrosion Control. Jour.
NEWWA, 112:1:60.
USEPA Guide to the Part 503 Rule. 1994
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