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Drinking Water Treatment and Distribution:

Removal and Regrowth of Bacteria

Assessments of Water Treatment Plant Performance

and Distribution System Water Quality


The attached report is a consolidation of four separate seasonal assessments of the performance of the Capital City Water Treatment Plant, Jefferson City, Missouri, in removing microorganisms and particles of potential heath significance from its Missouri River source.


In addition to traditional measures of drinking water treatment plant performance (turbidity, total coliform, heterotrophic plate counts), direct microscopic observations were made to quantify total bacterial cell removal as well as regrowth during distribution under both summer and winter conditions.


In addition, the treatment plant performance was assessed with respect to the removal of particle-associated bacteria (PAB), nematodes, and carbon 'fines' .


By all measures, microorganism removals were observed to be significantly impaired when water temperatures were low.

The electric vehicle market, which is just 3% of worldwide sales today is expected to triple to 9% by 2025.


According to a 2017 updated financial analysis by Bloomberg New Energy Finance (BNEF), that is just the beginning.


“EVs are on track to accelerate to 54% of new car sales by 2040.”


John O'Connor

Thank you, USEPA!

Posted by John O'Connor Mar 10, 2017

Thank You, USEPA!


Reflecting on the 47 years that you have served in protecting America’s environment, it seems appropriate that we, your clients and beneficiaries, give thanks both for the foundation on which you were created and for the specific benefits you have conferred on all Americans.


You were born as a result of intense public angst over sewage-polluted waterways, threatened drinking water supplies, open landfills, oil spills, fish kills, acid rain, industrial waste residues, and the virtually unchecked ravaging of America’s forests and streams following World War II. It took legislators more than a decade, but nationwide concerns ultimately culminated in the bipartisan National Environmental Policy Act (NEPA) of 1969, thanks largely to the efforts of Wisconsin Senator Gaylord Nelson, later the recipient of the National Medal of Honor in 1995.


As a result of NEPA, in 1970, (also the year of Senator Nelson’s first ‘Earth Day’ when 20 million Americans rallied), you were formally created to defend our nation against those assaults that could significantly impair our nation’s water, air, and land. You would also be called on to protect our endangered wildlife species and to guard the health of all Americans against the improper use and land disposal of toxic chemicals and hazardous materials.


In retrospect, it is remarkable to think that such protections were not already in place in a civilized, first-world, prosperous, mid-twentieth-century nation.


All grateful Americans, who recognize that we and our families now enjoy higher standards of living and health, thank you for the benefits you have bestowed to the nation.


So, what did USEPA accomplish over the past 47 years?




Sadly for some, Americans are driving less and using less gasoline.


Locally, increasing numbers of citizens are riding bicycles or opting for public transportation. Still others are buying scooters, mopeds and electric vehicles. To make matters worse, impending federal fuel efficiency standards are poised to further reduce vehicle fuel consumption. As a result of this perfect storm of disruptive trends, gasoline tax receipts continue to decrease significantly. Nationally, those seeking economy and energy independence are reportedly contributing to the ‘crumbling’ of America’s transportation infrastructure, ‘crippling economic growth, and hindering the development of sustainable, efficient communities’.

A Proposal for Advancing Columbia's (MO) Energy Future


The Social Cost of burning Carbon:

$36 per metric ton of Carbon Dioxide Released to the Atmosphere



John T. O’Connor, H2O’C Engineering, LLC, Columbia, MO


It was little noted, but on August 8, 2016, the Chicago-based 7th Circuit U.S. Court of Appeals unanimously upheld the U. S. Department of Energy’s policy of including the social cost of carbon at $36 per metric ton when calculating cost-benefit analyses. ( hange-accounting.) This court ruling is newsworthy because it permits federal agencies to quantify, rather than ignore, the external costs of climate change.

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An Editorial Assessment:

A Decade of ‘No Growth’ in Energy and Water Use is Good News for Columbia’s Economy


Tom O’Connor and John T. O’Connor, H2O’C Engineering, LLC, Columbia, MO


As it has for the nation as a whole, Columbia’s electrical usage has remained flat for the past decade. Even with a steadily growing population, Columbia’s per capita consumption declined from 32 kWh/d in 2006 to 27 kWh/d in 2015. This remarkable achievement may be a by-product of the adoption of new technology as well as community efforts to conserve and utilize electrical energy more efficiently.


If we can continue to use our resources more wisely, and thereby minimize the frequency of multi-million dollar utility system capacity expansions, Columbians will be richer for it in the long run.

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To encourage the adoption of renewable energy resources nationwide, the U.S. government has reauthorized (though 2019) the substantial (30%) tax credit to those homeowners installing solar energy systems. In addition to that federal incentive, Columbia’s Water & Light Department (CW&L) offers a generous 50 cent per Watt rebate on solar installations. CW&L is the only electric utility in Missouri that offers such a rebate.


Considering these dual financial benefits, what might it cost a homeowner to install a typical 5,000 Watt (5 kW) residential solar system in Columbia Water and Light’s service area?



For the past year, I have been obsessively plowing through the waterworks literature, research reports, news articles, public health publications with recent data, histories [e.g., Brush with death: a social history of lead poisoning, Johns Hopkins University Press, 2001], informal publications, blogs, reader comments, and, most intently, the results of Michigan’s official inquiry [Flint Water Advisory Task Force Final Report, March , 2016] related to the toxicant, lead - particularly in drinking water supplies.


Although admittedly from a distance of 629 miles (Columbia, MO to Flint, MI), I have been trying to learn what happened in the Flint, Michigan water system - and what water suppliers must learn from this distressing episode.


The story begins with the efforts of Michigan’s state-appointed emergency managers (EMs) attempting to reduce the expenditures, including that for water supply, of the poverty-stricken City of Flint which was in debt - and in financial receivership.      John T. O’Connor



Finally, challenging the reader to a ‘thought experiment’.

What kind of experiments would you propose to gain insight into whether observed elevated lead levels are influenced more by ‘physical disturbances’ or ‘chemical factors’, such as disinfectant concentration, depletion, and temperature?

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The attached summary of research on water treatment processes, conducted at the Little Rock, AR. Municipal Water Works (LRMWW) from October 1993 to January 1996, may be of special interest to water treatment professionals.


The summary outlines the:


Evaluation of Water Treatment Plant Performances

Safe Drinking Water Act Compliance Assessments

and a review of Pilot Plant Start-Up and Operations.




Also attached is a 1994 technical presentation (ASCE-Environmental Engineering Division conference) detailing the results of studies of the Control of Microbial Water Quality in the Little Rock, Arkansas Distribution System.


Finally, The Effect of Seasonal Variations in Source Water Quality on Drinking Water Treatment Process Requirements is presented as part of an interpretation of USGS data on Lakes Winona and Maumelle.





For millennia, humans have sought out healthy sources of potable water - and worked to devise means for purifying dirty or polluted waters.


The earliest small-scale treatments often involved heating or boiling as well as rudimentary filtration, aeration, and storage. Even distillation was among the early techniques devised.


Mechanical means for water treatment (filtration) awaited the tools and materials provided by the industrial revolution.

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"What is the chlorine residual at your household tap?"


The answer may depend upon who is doing the sampling - and what answer they would prefer to see.


Any value from zero residual at the 'first draw' for your morning coffee to the distribution main's total residual can be recorded, depending on the volume of water drawn before sampling. Where household plumbing is flushed for three to five minutes before sampling, as recommended by the AWWA Committee on Bacteriological Sampling Frequency in Distribution Systems (1985), it is the distribution system main, and not the consumer's tap, which is being sampled.


Part of the reason your system might be purged before sampling is that it is always summer for your heated household plumbing. Warm temperatures encourage microbial growth, nitrification, oxygen depletion, chlorine depletion and, sometimes, corrosion of plumbing materials.


To purge microbial growth and their by-products, one is well-advised to run the water until it is as cool as the water in your water distribution main.


For the few that are interested in this microbially-mediated phenomena, the attached paper may explain why.




John Wiley & Sons, publishers of "Water Treatment Plant Performance Evaluations and Operations", 2009, has generously posted the following excerpts from this volume on their website, free for downloading.


The WTP Preface provides the outline and summarizes the 12 chapters of a volume created for water treatment plant operators and managers focussed on scientifically monitoring and improving plant process performance.


Perhaps of greatest scientific value in this release are the WTP Figures. This central element of the book provides 28 highly detailed, color micrographs of particles and organisms observed in water at various stages of collection and treatment. The descriptions accompanying each figure represent an attempt to put the information conveyed by each micrograph to practical operational use.


Appendix A (appA) describes the apparatus needed and basic procedures for conducting bacterial cell counts by epifluorescence microscopy.


Appendix B (appB) lists potential studies that a water utility might perform using microscopic particle analysis.


Appendix C (appC) starts with a discussion of operator responsibilities and operational data collection. This is followed by an extensive photographic tour of an operator 'making the rounds' to directly observe the functioning of the water treatment plant unit processes.




John O'Connor


Posted by John O'Connor Jul 16, 2015

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In the production of municipal drinking water, nothing is monitored more assiduously than turbidity.


Why is this so? Just what is turbidity? And why is this quality parameter so critical that it rates designation as a microbiological surrogate and primary drinking water standard?


Direct microscopic examination of drinking waters reveals that turbidity is caused by stuff - stuff that absorbs or scatters light. As you might imagine, light-scattering stuff may include silt, clay, cyanobacteria, precipitated carbonates, sulfides, metal oxides (e.g., rust and corrosion products), plant fibers and organic debris, microfloc, activated carbon 'fines', paint chips, nematodes, protozoans, cysts, bacteria, virus, ... (Oddly, while they may sometimes be present in large number, bacterial cells are so translucent that they contribute little to either the turbidity of natural - or treated drinking waters.)


The attached report, "The Effect of Lower Turbidity on Distribution System Water Quality", (AWWARF, 1993), includes analyses of sets of operational data from a broad range of major U.S. water utilities (Kansas City, MO; St. Louis, MO; St. Louis County (MO) Water Company; New Orleans, LA; Boston, MA; Baltimore, MD; New Haven, CT; Cleveland, OH; Louisville, KY; Dallas, TX; Phoenix, AZ; Oakland, CA; Los Angeles, CA; Metropolitan Water District of Southern California).  From this data, the seasonal relationship between each utility's treated ('finished') water turbidity and the frequency of recovery of total coliform and heterotrophic plate count (HPC) organisms in monitoring samples from the water distribution system could be determined.


Of special interest, a comparison of data from various utilities indicated a very distinct advantage in maintaining control over total coliform in the distribution system using chloramine as opposed to chlorine.

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Attached is a listing of all posts to Water and Wastewater Slide Shows as of March 2020.

Some are for chemists, some for engineers, some for students and scholars, some for water and wastewater system operators; all for downloading and use at your discretion.

We encourage your comments, especially if some of these posts have been helpful.


Water and Wastewater Slide Shows: and Wastewater Slide Shows


Bacteria in Drinking Water


The Age of Electric Vehicles


Thank you, USEPA!


All-Electric Vehicles - and Gasoline Taxes


The Social Cost of Burning Carbon


An Editorial: A Decade of ‘No Growth’ in Energy and Water Use


Residential Solar System Costs - Columbia, Missouri


Lead Contamination of the Flint, Michigan Water Supply: A Distillation of Readily Available Information  - Updated to May 2016


Little Rock, AR., Municipal Water Works - 1996


Early History of Water Treatment


Kinetics of Chlorine Depletion and Microbial Growth in Household Plumbing Systems


Microscopy - for Water Treatment Plant Performance Evaluations




The Story of Bottled Water and other Slide Shows: iBook


Summary of Posts: 2010-2016


Bottled Water Exhibit: University of California-Davis (Video)


Water Chemistry


Water Softening by Precipitation with Lime


Taste and Odor Control at Bloomington, Illinois


Drinking Water Filtration: Replacement of GAC Caps at Bloomington, Illinois


What we can’t (or shouldn’t) put into our Sanitary Sewerage Systems


Anthropogenic Global Warming


A Drinking Water Supply Manifesto




Control of Nitrification in a Water Distribution System


Air-Assisted Filter Backwash (Air Scour)


Virus in Water Supplies


Chlorine vs. Chloramine


Drinking Water Process Performance Evaluations


Total Organic Carbon - Health Effects


Total Organic Carbon Removal


Total Organic Carbon


Pharmaceuticals in Water and Wastewater


Wastewater Reclamation, Recovery and Reuse


Stream Biomonitoring


Methane in Ground Water


Household Electrical Energy Usage


Sustainability for Water Systems


Arsenic in Drinking Water


Pit Happens: Copper Corrosion in Household Plumbing


My Kitchen Tap versus My Refrigerator Dispenser


A Brief History of Human Waste Disposal - Part 6. The Future



A Brief History of Human Waste Disposal-Part 5. Wastewater Treatment


A History of Human Waste Disposal - Part 4. Sewage Treatment


A Brief History of Human Waste Management - Part 3: Sewerage


A Brief History of Human Waste Disposal - Part 2: Toilets


A Brief History of Human Waste Disposal - and its possible future.


The Story of Bottled Water


Steps toward Sustainability tainability2.pdf