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Posted on 24 November 2016 by Hubert Colas
Posted in FluksAqua insights, Utility management, Water and wastewater community,

In 2015, contaminated drinking water exposed many Americans to chemicals, bacteria and disinfecting byproducts. FluksAqua’s analysis, presented in an interactive infographic released last month, reflects the concerns expressed by water operators in our online forum.

dirty water contaminants


FluksAqua’s analysis found the key contaminants to be coliforms, nitrates, arsenic, radionuclides and disinfection byproducts. Water operators are concerned about these contaminants because they can affect human health and also have impacts on the environment. Although the Walkerton, Ontario E. coli crisis happened more than 16 years ago, the disaster is still a powerful example of the need to maintain vigilance for water quality and safety.

The presence of coliforms in our water systems is related to a number of factors, including filtration processes, water temperature disinfectants, corrosion control, pipe materials and maintenance. FluksAqua forum user gpcelina identified several methods to test for coliforms, saying, “Manual methods are time-consuming and include plating and incubating bacteria, followed by Gram staining, preparing a McFarland (Standard) and performing a whole battery of tests. Presumptive identification is made much simpler nowadays by using API 120E ™ test strips.”(Add your preferred techniques to the list!)

Contaminated drinking water: what are the contaminants


 On the forum, two water quality issues water professionals discuss relate to  sources of mercury contamination and the removal of prescription drugs from our water systems. One of the challenges with mercury is that by the time its presence is detected, the damage is done.

The Environmental Protection Agency (EPA) is developing new guidelines to manage the discharge of mercury as an effluent. As pointed out in the forum discussions, a common source of mercury is dental clinics. The EPA reported that dental offices discharge an average of 4.4 tons of mercury into our collection systems, and 50% of the mercury found in US water systems comes from dental offices. The new guidelines will set pre-treatment standards, and dentists will be responsible for controlling the amount of pollutants discharged.

Reducing the entry of contaminants is key, but sometimes even with proper filtration, contaminants remain. One joint Canadian-American study found almost half of contaminants remained in the water system after treatment. As Brian Bienkowski of Environmental Health News reported, “The wastewater plants had a low removal rate (less than 25 percent chance of removing 75 percent or more) for 11 of the 42 chemicals.”


 Last April, FluksAqua examined the impact of the increased disposal of pharmaceuticals in the water system. Prescription drugs are more difficult to limit in large part because they are excreted. However, many water operators have noted in the FluksAqua forum that people often dispose of leftover medications by flushing them down the toilet.

Water operators find it challenging to remove drugs from the water supply because filters are designed to remove solids. While activated charcoal and reverse osmosis are the most frequently suggested approaches, water treatment processes are evolving, particularly in response to the demand posed by large amounts of micropollutants.

For smaller plants, the cost that comes with more specialized processes may be a barrier. Forum user sles7 said, “Cost is the biggest issue.” While water operators should implement these multiple methods of removal to protect the water supply, consumers are often reluctant to accept increased taxes to cover water treatment costs.

The effectiveness of such treatments is also quite varied. Forum user tamie said, “The effectiveness of treatment for the removal of pharmaceutical compounds varies greatly from one type of treatment to another. Those that are the most successful are also the most expensive, and most plants are not equipped to provide such treatments.”


Contaminants, like hazardous waste and garbage in the system, can largely be reduced at source through greater public awareness. But even if we can persuade consumers not to use the water system to dispose of excess medications, or industrial sites to be more aware of runoff issues, water operators still need the resources to maintain effective measures for water quality and safety.

The FluksAqua forum is a great place to discuss all the challenges of managing contaminants, and share the solutions you have found. 

  1. What processes are you using to treat water in your plants?
  2. What kinds of education campaigns have you used to raise awareness of the public’s role in keeping water systems safe?
  3. What other ways can water operators and other professionals in the water industry improve our water systems?
  4. What resources do you need to reduce contaminants in your plant?

In the FluksAqua forums, you can keep up with what’s new in the industry, seek support from other experienced operators, or help your colleagues with their operational issues. If you’re hearing concerns from your colleagues and the people in your communities, share them with us! Our members represent organizations and communities that contribute key indicators we can use to measure and compare the performance of water networks all over the world.

Join us at FluksAqua’s online Q&A forums to talk about how you plan to ensure that water quality remains a top priority.


About the author

Hubert Colas, Eng., Ph.D., is a senior executive at FluksAqua with more than 25 years of experience in consulting engineering and technology development.
In previous functions, Mr. Colas spearheaded a world-class leader in the design and operation of real time control of urban drainage systems. Hubert Colas implemented complex solutions to manage wet weather in real time and provided services and solutions to water and wastewater utilities.