A New Perspective of Lead and Copper Control in Drinking Water
Water Research Foundation Report 4586 - Optimization of Phosphorus-Based Corrosion Control Chemicals and Flushing for Lead and Copper Control

A new report from the Water Research Foundation (WRF) challenges common understandings of lead control in drinking water. The research finds that Lead and Copper Rule compliance in public water systems is best maintained through a comprehensive approach, rather than focusing on two common techniques of lead control advocated by the national drinking water regulations.

The WRF released the findings of Project 4586, Optimization of Phosphorus-Based Corrosion Control Chemicals Using a Comprehensive Perspective of Water Quality in November 2017. In addition to the Water Research Foundation (Denver, CO), the research was sponsored by the Water Environment & Reuse Foundation (Alexandria, VA), and eight anonymous drinking water utility entities. The report is available for free to the public as a pdf file from the Water Research Foundation website.

Written by A.F. Cantor, P.E., chemical engineer, head of Process Research Solutions, LLC in Madison, Wisconsin, the 39-month study determined that water utilities should not focus on orthophosphate addition or pH and alkalinity adjustment to control lead and copper concentrations in drinking water, but should broaden their approach to include routine infrastructure improvement, ongoing water biostability improvement programs, and ongoing tracking of water system data and information.

The goal of the project was not to tear down institutional concepts, but to build up a larger perspective — to look at lead and copper release more comprehensively, to treat the problems and not the symptoms, and to add more tools to the toolbox.

While lead and copper control has been a drinking water industry concern for decades, lead in drinking water has been a major concern of the general public since 2016 when the Flint, Michigan, water quality crisis was publicized. The Flint case was not a subject of study in this research; however, Flint is a good example of how a water quality and public health catastrophe could have been avoided if the comprehensive perspective of water quality, presented in the WRF study results, had been applied before switching the water source to the Flint River. WRF Report 4586 showed that existing chemical scales and biofilms on pipe walls have a profound effect on shaping the water quality that consumers experience. In addition, the chemical and microbiological nature of the system’s source water sets the stage for the water quality in the distribution system. The Flint case was a “system hygiene” issue, revolving around water system cleanliness and biostability of the water.

Changing Assumptions
The assumption that adding orthophosphate to drinking water is guaranteed to prevent lead release in cities, such as Flint, over-simplifies the complexity of the factors at work.

Lead and copper typically enter drinking water through the water’s interaction with piping materials. There are two commonly used lead-and-copper-control strategies in drinking water systems — orthophosphate addition and pH/alkalinity adjustment. Although defined scientifically by lead and copper solubility models, the chemistry, in many cases, cannot occur as predicted in actual water systems where many other chemical and microbiological interactions are occurring at the same time. These findings do NOT imply that the current lead and copper control strategies of orthophosphate addition or pH/alkalinity adjustment should not be used. On the contrary, the findings show that they are two of MANY factors that must be considered in determining how to approach lead and copper control in a given water system.

But many water systems around the United States have claimed success at lead and copper control using the two standard techniques. How can the findings of Project 4586 be reconciled with this? The pH/alkalinity adjustment or orthophosphate dosing is most likely effective in specific water systems, but the effectiveness of orthophosphate and pH/alkalinity adjustment may be an illusion in other water systems for a number of reasons.
  • Several water quality parameters can play a role in both chemical and microbiological interactions, and the true reason that adjustment of a specific water quality parameter has been effective for lowering lead and copper release may not have been properly identified.
  • Other water system operations, such as carrying out a high-velocity flushing program, reducing system residence time of water, eliminating nutrients in the water, or cleaning filters, may be occurring simultaneously to the presumed corrosion-control strategy and may actually be the real influencing factors on corrosion control.
  • Follow-up sampling of the outcome of the corrosion-control strategy may be inadequate and not representative of actual effectiveness. For example, many water quality parameters are NOT measured in a corrosion control study and their influence on lead release cannot be ruled out.
Using the Comprehensive Perspective to Control Lead and Copper Release
While carrying out orthophosphate addition or pH/alkalinity adjustment is relatively simple, lead and copper control by means of the comprehensive perspective developed by the WRF research requires ongoing attention. But these are the same actions that should be taken for upkeep of infrastructure anyway.

The report lists specific steps that should be taken and shifts the paradigm on water system operation as it relates to water quality. In general, a clean water system with biologically stable water has low potential for lead and copper release. It also has as low potential for the occurrence of other water quality issues such as discolored water, formation of carcinogenic disinfection by-products, and growth of microorganisms that can cause immediate illness. The basis of water quality control, including lead and copper control, should be this new focus on water system hygiene.

Using the comprehensive perspective of water quality in Project 4586, eight water systems underwent various degrees of “system hygiene” as data were gathered from the systems. Lead and copper concentrations in water systems undergoing cleaning and biostability actions were lowered. The water systems that were out of compliance with the Lead and Copper Rule were brought into compliance using this comprehensive approach.

The report challenged common understandings of lead and copper corrosion control. The goal of the project was not to tear down institutional concepts, but to build up a larger perspective — to look at lead and copper release more comprehensively, to treat the problems and not the symptoms, and to add more tools to the toolbox.
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A Step-by-Step Approach to Water Quality Control and Improvement
Second Edition of CRC Press Book - Water Distribution System Monitoring: A Practical Approach for Evaluating Drinking Water Quality

It has been eight years since the first edition of Water Distribution System Monitoring book and that is eight more years of honing the techniques in actual water systems. This book is truly a step-by-step approach for all water systems to pave a path toward high water quality drinking water. The book can be ordered from many on-line book stores, including the publisher's at

This book tackles the complexity of water distribution systems. It is a practical step-by-step approach to understanding and controlling the drinking water quality that consumers experience in a water system. It demonstrates how to be proactive on water quality issues through routine monitoring of the distribution system and is written to help the practitioner prevent the devastating and costly effects of:
  • Falling out of compliance with the Lead and Copper Rule
  • Developing pinhole leaks in water service lines and private plumbing
  • Leaving the water distribution system vulnerable to microorganisms that can cause illness or can corrode metals
  • Experiencing unwanted side-effects from treatment chemicals
  • Adding the wrong water treatment chemical or using the wrong dosage
  • Alarming consumers with water that is discolored or has a bad odor
  • Releasing other metals that have accumulated in the distribution system that may cause consumer health issues, such as arsenic or radium
This book describes a path to well-defined and measurable control of the distribution system water quality that the consumers experience.
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Best Practices for Drinking Water Quality in Buildings
Booklet, "What's Bugging Your Pipes - How Microorganisms Affect Plumbing Systems"

Individual buildings can have water quality problems. Much attention is currently focused on "premise plumbing" water quality issues. Here is a booklet that called attention to the issues starting in 2013.

To Plumbing and Building Contractors: There are many new plumbing systems with discolored water, high lead and copper concentrations in the water, holes in copper pipes, and quickly corroding hot water tank anode rods. This mostly occurs from modern plumbing designs that unintentionally promote the growth of microorganisms. This booklet is for you so that these issues will be understood and taken care of properly. Help prevent the future from being filled with ruined plumbing systems, angry property owners and liability lawsuits.

To Municipal Water Utility Managers: The future revision of the Lead and Copper Rule, with a new focus on copper, will probably result in the water utility carrying the blame for the high copper situation in many new plumbing systems. This booklet will explain how you can make sure and document that the municipal water system is not part of the problem. Don't get blamed for ruined plumbing systems!

This booklet is a resource on microbiologically influenced corrosion as it occurs in plumbing systems of buildings. The book covers understanding, prevention, and remediation of the resultant water quality and pipe integrity problems.
Purchasing information.

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Training for Water Quality Control and Improvement
University of Wisconsin Professional Development Class on Water Quality in Distribution Systems and Building Plumbing

Do you want to know what happened in Flint, Michigan, and if it could happen in your municipal water system or building plumbing system?

Abigail Cantor of Process Research Solutions teaches a course in Madison, Wisconsin along with Professor Gregory Harrington of UW-Madison Civil and Environmental Engineering on water quality in distribution systems and in building plumbing. The goal of the class is to give the participants the initial steps to understanding the chemistry and microbiology unique to their water system and the initial steps to improving the water quality. Compliance with the Lead and Copper Rule, the Total Coliform Rule, and the Disinfection Byproducts Rule for municipal water systems is addressed. Legionella, pinhole leaks, and other building plumbing issues and remedies are also addressed.

The next class is scheduled for October 10 and 11, 2018. Registration is available at the UW Engineering Professional Development website.
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The Comprehensive Perspective and the Flint, Michigan Water Quality Crisis

The Flint, Michigan, water quality and public health crisis is still fresh on the general public's mind because of the publicity that it received. Process Research Solutions, LLC, was not involved in any aspect of the Flint crisis. However, the crisis is mentioned here because people can immediately understand and envision what is meant by lead release into drinking water and other water quality issues. From reading available information regarding the Flint water system, it can be seen that this case fits the comprehensive perspective of water quality as has been developed by Process Research Solutions.

The Flint River had previously been studied by the State of Michigan Department of Natural Resources. It was known that there were high microbiological populations in the water, known sewage contamination episodes, and high nutrient loading (organic carbon, phosphorus, and nitrogen compounds), all of which demonstrate a biologically unstable water at critical levels. In addition, there were high chloride levels in the river water, which should have caused a chemical corrosion alert.

Trial attempts at treating the water with the existing filtration plant showed that appropriate turbidity levels could not be reached. Turbidity is a measure of particulates in the water. It is a major parameter to monitor for filtration of water, a treatment process that removes particulates in the water. Measuring turbidity is a standard practice when water is filtered to determine if the treatment process is working correctly. In Flint’s case, the turbidity could not be brought down to acceptable levels with the filtration process.

Additional information about microbiological populations, nutrient levels, and chloride levels in the treated water should have put a halt to the plan to introduce the water into the distribution system pipes. However, it is not a standard of practice to measure such parameters after a filtration process as would have been performed when following the comprehensive perspective of water quality.

With the comprehensive perspective of water quality, there would have also been many red flags regarding the state of the distribution system. The water mains were unmaintained and contained large quantities of chemical scales and biofilms that had accumulated over decades; not only can these accumulations have chemical and microbiological interactions leading to lead release but the chemical scales can also aid in accumulating and transporting lead to consumers’ taps.

In addition, the drinking water in the Flint water system has a high residence time. That is, it is a long time from when a specific drop of water is introduced into the distribution system from the treatment plant to when that drop of water comes out of a faucet for use. A high residence time of water allows microorganisms to grow excessively and form self-protective biofilms on surfaces to a point where disinfection cannot win the fight against their populations. In Flint, the water system was built to supply water to twice the number of consumers that were actually utilizing the water system. This means that water typically stays in the water pipes for a long period of time and most likely undergoes many microbiological and chemical changes.

After the water quality crisis occurred, many people — in the drinking water field, in the regulatory agencies, in the news media, and even a comedian proclaimed that if only orthophosphate had been added, the water quality crisis would not have occurred.

However, even the Virginia Tech researchers found that orthophosphate did not significantly lower the lead corrosion in the treated Flint River water. (Click here for one article and here for a second article.)

In addition, the Flint River study suggests that there were already high levels of orthophosphate in the Flint River water from agricultural runoff.

Using the comprehensive perspective, it would have been a priority to properly clean chemical scales and biofilms from the water mains and to lower the residence time of water in the distribution system. Using the comprehensive perspective, the Flint River water would have been rejected as a potential drinking water source because it was biologically unstable and also contained high chloride levels. Or, a very complex water treatment system would have been installed to manage these contaminants.

In summary, the Lead and Copper Rule suggests that the addition of orthophosphate to the treated Flint River water for drinking water in the city of Flint, Michigan, would have prevented the catastrophic water quality issues that were experienced. However, tests performed by Virginia Tech researchers suggest that orthophosphate addition did not significantly lower the lead corrosion in the water system. In addition, a Flint River report suggests that there was already an elevated level of orthophosphate in the water. Instead, the comprehensive perspective of water quality would have alerted engineers to the issues of biologically unstable source water and the presence of elevated corrosive chloride in the Flint River. The perspective would have further alerted engineers to an unmaintained and oversized distribution system capable of interjecting multiple significant factors for the release of lead and the occurrence of other water quality issues.

The comprehensive perspective should be adopted so that water systems can begin a path of system hygiene – that includes pipe cleanliness and biologically stable water. These distribution system water quality issues are preventable with a comprehensive focus.
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