Water Quality Testing

waterQualityTestingBiotoxicitytestingCOCAlthough most areas in North America enjoy large amounts of high quality drinking water available at the push of a button, our drinking water sources are changing dramatically! Both environmental factors from climate change and human activities are responsible for altering the amount and composition of available fresh water. Analytical techniques for evaluating water quality continue to improve and more chemical compounds are entering our aqueous environments at astounding rates. Approximately 15,000 new chemicals are added per day to the chemical registration database (www. cas.org). Our current paradigms for evaluating environmental and human health effects cannot possibly keep up with chemical development and commercialization. Bioanalytical tools (Bioassays) can detect molecular or cellular toxicity events that occur at environmentally relevant concentrations. These assays are valuable tools in various water assessment applications due to their high throughput capabilities, relatively low cost and ability to detect cumulative and mixture effects. For these reasons they are increasingly being recognized and applied for water quality assessments. 

Drinking Water

wastewater article 3

Changes in Source Water

Drinking water scientists of all types deal with increasingly variable source waters that contain a variety of chemical contaminants such as pesticides, chemicals formed during water treatment, human pharmaceuticals and other xenobiotics. These chemicals have differing human health risk profiles, as some can be acutely toxic and result in immediate adverse health effects, while others pose chronic health risks and only produce adverse effects after prolonged continuous exposure. Drinking water standards are generally set for specific chemicals that are likely to be found in water sourced from conventional sources such as surface water or groundwater. However, those same drinking water standards may not be appropriate for less traditional water sources such as water reclaimed from wastewater, which can contain very different chemical composition and/or concentrations that introduce new human health risks. Evaluating these alternative drinking water sources using bioassays is already being done as a way to screen large amounts of samples prior to investing in more costly, and potentially less powerful analytical techniques.

Reference Publications

  1. Leusch, F. D. L., Snyder, S. (2015) Bioanalytical tools: half a century of application for potable reuse, Environ. Sci.: Water Res. Technol.,1, 606-621
  2. Jia, a., Escher, B. I., Leusch, F. D. L., et al. (2015) In vitro bioassays to evaluate complex chemical mixtures in recycled water, Water Res., 80, 1-11
  3. National Research Council, Water Reuse. Potential for expanding the nation's water supply through reuse of municipal wastewater, National Academies Press, Washington, DC, USA, 2012


Disinfection By-products

Chemical disinfection of drinking water has provided one of the worlds most significant public health triumphs by virtually eliminating microbial infections from this route of exposure. Decreased mortality from waterborne diseases such as cholera, dysentery, and typhoid fever have all resulted from disinfection of public water sources. Although disinfection provides significant protection from waterborne microbes, an important side effect from this process is the formation of carcinogenic disinfection by-products (DBP) in treated water sources. DBPs are produced from reactions between oxidants used to treat the water, and natural organic matter (NOM) present in the source flow.  The concentration, type and abundance of DBPs formed depend on a variety of factors including temperature, pH, disinfectant type and application location. Traditional disinfection has mainly involved the use of chlorine, but with recent research into DBP formation, alternative methods like ozonation or chloramine addition have become popular alternatives. Chlorine however, is still employed in combination with these alternative methods due to its residual action throughout the distribution system. 

Figure 1: Formation of disinfection by-products (DBP) from waste water treatment. 

Chloroform was the first DBP found in drinking water by Rook in 1974, which prompted the EPA to establish drinking water regulations for trihalomethanes (THM) by 1980. Currently more than 500 unique DBPs have been identified, although less than 50% of the total organic halide (TOX) content in treated water belong to DBPs that are actively quantified. Only 20-30 of the most abundant DBPs have received significant attention, and they include  4 regulated THMs, 9 total chlorinated and brominated haloacetic acids (HAA), 4 haloacetonitriles, aldehydes, chloral hydrate, chloropicrin, and bromate. This means that the vast majority of DBPs remain largely undetected, although successful monitoring of all 500 DBPs would involve massive monetary as well as time investment and is virtually impossible. Fiscal and time constraints encourages testing strategies for DBP mixtures using biological tests, not only to provide more relevant data on a greater number of compounds, but also to improve the link between in vitro studies which look at individual compounds, and epidemiological data which must utilize exposures to mixtures. Furthermore, testing mixtures improves risk assessment for water chlorination, as exposure concentrations are relevant, multiple routes of exposure are considered, synergistic effects are observed and effects from rare DBPs present at low concentrations are studied. 

water quality testing disinfection

Reference Publications

  1. Martijn, A. J., Kruithof J. C. (2012) UV and UV/H2O2 Treatment: The Silver Bullet for By-product and Genotoxicity Formation in Water Production, Ozone: Sci. and Eng., 34, 92-100
  2. Macova, M., Escer, B. I., Reungoat, J., et al. (2010) Monitoring the biological activity of micropollutants during advanced wastewater treatment with ozonation and activated carbon filtration., Water Res., 44, 477-492
  3. Krasner, S. T., Chih Fen Lee, T., Westerhoff, P., et al. (2016) Granular Activated Carbon Treatment May Results in Higher Predicted Genotoxicity in the Presence of Bromide, Environ. Sci. Tech., 60, 9583-9591
  4. Simmons, J. E., Teuscher, L. K., Gennings, et al. (2004) Component-based and whole-mixture techniques for addressing the toxicity of drinking-water disinfection by-product mixtures. J. Toxicol. Environ. Health A, 67, 741–754
  5. Bull, R. J., Reckhowb, D. A., Li, X., Humpaged, A. R., Joll, C., and Hrudey, S. E., (2011) Potential carcinogenic hazards of non-regulated disinfection by-products: Haloquinones, halo-cyclopentene and cyclohexene derivatives, N-halamines, halonitriles, and heterocyclic amines, Toxicology, 286, 1– 19


Waste Water

Testing Effluents for Mixture Effects

drain pipe waterQualityTestingMunicipal wastewater can contain a wide range of natural and synthetic chemicals, including personal care products, household chemicals, industrial products, natural and synthetic hormones and pharmaceuticals, and chemicals formed during wastewater treatment. Effluent regulations are in place to protect both ecosystem and the public health. However, even extensive chemical monitoring can only detect a limited subset of the vast number of chemicals that are likely present and only those above a methodologically defined detection limit that is constantly evolving. Beyond the large number of chemicals produced, each one has the propensity to form transformation products in the environment. Biological toxicity testing is a crucial additional tool to ensure the chemical safety of effluent water and discharge waters. 

  • Hundreds of thousands of chemicals are used commercially and new substances are introduced daily. 
  • There are numerous unintended by-products and transformation products of these chemicals in our water supplies arising from human metabolism and excretion as well as environmental breakdown products, disinfection by-products and microbial metabolites. 
  • Some compounds are persistent, can bioaccumulate and are potentially toxic (PBT).
  • Mixtures of chemicals can have adverse additive or cumulative effects on organisms, although individual components of the mixture are below effective levels.
  • Total composition of a waste water effluent is not known since only a few substances have been analytically identified from it.

 Although testing deficiencies are apparent, regulatory organizations in many countries have mandated the use of bioassays for effluent regulations. Regulation of euents can take many dierent forms depending on the stated objectives. Standards are used for dierent environmental protection goals including

(1) Protecting the quality of the receiving environment (point of contact standards), 

(2) Reduce emissions to the environment based on load (point of entry standards). 

The first standard is based on a site-specific risk assessment, i.e., the bioassay standard or limit is designed to be protective of the receiving environment and may take account, for example, of the sensitivity of the receiving environment or the available dilution. They are designed to meet water quality objectives for any particular site. These standards are often expressed as permissible toxicity in euents using specific tests and endpoints including luminescent bacteria or Daphnia magna. Emission limit values or load values, are designed to promote the use of ‘best available technology’ for a specific industry sector, regardless of the receiving environment. These latter standards restrict overall load releases and may be thought of as a hazard based standard. 

Effluent Assessment Frameworks

Biological assays are employed for data collection in numerous whole effluent assessment (WEA or WET) frameworks that are legislatively regulated. These documents set out guidelines for methods to assess water quality of effluent discharge, but also present threshold values to determine acceptable exposure levels. Different countries have established slightly different methods of measuring and assessing safety but biological assays are employed in more frameworks.

United States

  • WET used in the National Pollutant Discharge Elimination System (NPDES) to meet permit regulations and control toxic discharges from industry
  • All States are required to implement WET procedures under the Clean Water Act (CWA 1972)


  • Waste Water Systems Effluent Regulations employ bioassays for specific industries like
    • Pulp and Paper Effluent – must use both Rainbow Trout and Daphnia Magna
    • Metal Mining Effluent – Acute lethality of Rainbow Trout and Daphnia Magna
  • Point discharge regulations involve biological assays for a variety of industries.
    • Oil and gas industry employs the luminescent bacteria test for drilling waste
  • Results of toxicity tests and biological assays are used to derive safe threshold values for a number of priority water contaminants listed on the Canadian Council of Ministers of the Environment (CCME) Canadian Environmental Quality Guidelines


  • Water Framework Directive
    • Broader in scope, provides additional protections above regulations in Canada and USA.
    • Bioassays are used as indicators of hazard in assessments
    • Employs both traditional whole organism bioassays and newer assays that employ bacteria and other organisms to look for different endpoints (genotoxicity)
    • Emphasis on achieving good biological status as well as chemical status


Reference Publications

  1. Lahnsteiner, J., and Lempert, G. (2007) Water management in Windhoek, Namibia. Water Sci. Technol., 55, 441-448
  2. Gartiser, S., Hafner, C., Hercher, C., Kronenberger-Schäfer, K., and Paschke, A. (2010) Whole effluent assessment of industrial wastewater for determination of BAT compliance. Part 2: metal surface treatment industry. Environ. Sci. Pollut. Res., 17, 1149-1157.
  3. OSPAR commission (2002) Survey on Genotoxicity Test Methods for the Evaluation of Waste Water within Whole Effluent Assessment. London
  4. COHIBA WP 3 Participants, (2010) Whole Effluent Assessment (WEA). Helsinki, Finland
  5. http://www.ccme.ca/en/resources/canadian_environmental_quality_guidelines
  6. http://ec.europa.eu/environment/water/water-framework/index_en.html
  7. https://www.epa.gov/npdes/whole-effluent-toxicity-wet


Community Based Monitoring in Remote Locations 

Water Crisis in First Nations Communities

community based monitoringCanada is rich with fresh water and Canadian citizens enjoy one of the highest amounts of water available per capita. It is therefore both alarming and embarrassing that in this land of plenty certain residents do not have access to clean water and are under constant pressure to purify water sources available to them. The vast majority of those affected by a lack of clean water are First Nations people and remote northern communities, who encompass only 4.3% of the Canadian population but are disproportionally affected by poor water quality. 

Several factors contribute to the poor overall water quality being delivered to First Nations communities. They include 

  1. Lack of appropriate infrastructure
  2. Antiquated treatment technologies that cannot accommodate community size
  3. Lower source water quality from natural factors, upstream industrial activities
  4. Significant gaps in legislation to set water quality standards.

These factors underlie several shortcomings in the management practices and governance of water sources and highlights historical inequities in the negotiation and interpretation of Indigenous rights by Canadian governments. Human Rights Watch states that there were 134 water systems in 85 communities that were under boil water advisories in 2016 across Canada. Some First Nation communities have suffered boil water advisories for decades. Provincial governments regulate water quality for off-reserve communities but no binding regulations are in place for water on First Nations reserves.

The most popular approach to address this crisis situation has been to increase funding for treatment facility and infrastructure improvement. Despite several financial commitments since 1977, the problem of poor water quality remains pervasive and is not improving. Billions in federal investment have not solved the problem, illustrated by more than 30% of drinking water advisories being in place for over 10 years.  In March 2016, Prime Minister Trudeau announced yet another investment of $4.6 billion over the next 5 years to improve infrastructure in First Nations communities but little is expected to change without significant commitments to fixing other contributing factors and a radical change in governance philosophy. Employing bioassays in communities to evaluate improvements to treatment methods on site, and testing source water for toxicity from upstream activities will facilitate positive changes from within the communities and help to fix the water crisis in First Nations communities. 

Reference Publications

  1. Wolfley J. (1998) Ecological risk assessment: their failure to value indigenous traditional ecological knowledge and protect tribal homelands. Am. Indian. Cult. Res J., 22, 151-169
  2. Phare, M. A., (2009). Denying the Source: The Crisis of First Nations Water Rights. British Columbia, Canada: Rocky Mountain Books
  3. MacDonald, D. D., Clark, M. J. R., Whitfield, P. H., and Wong, M. P. (2009). Designing monitoring programs for water quality based on experience in Canada I. Theory and framework. Trends in Anal. Chem., 28, 204-213
  4. Health Canada (2011) Ensuring Safe Drinking Water in First Nations Communities in Canada. Retrieved from http://www.hc-sc.gc.ca/fniah-spnia/promotion/public-publique/sfw-sep-eng.php


Community Based Monitoring Programs

Community Based Monitoring (CBM) programs are becoming more popular across many regions in Canada and abroad. These projects use citizen scientists to gather data on water quality and increase capacity within communities to independently test for quality and contamination. Rapidly gaining in popularity (350% since 2000) these programs permit communities to address specific problems with their own water sources, help fill knowledge gaps in water quality which can be expensive if done by traditional methods and incorporate traditional values from communities into these assessments. These factors increase the amount of data produced and build trust in the data obtained. These programs benefit greatly from bioassays since these tests can address the issue of cumulative effects, are simple enough to be conducted by community members without much training and are robust enough to be deployed into the field. When combined with analytical methods or used as a screening tools to evaluate many samples prior to more specific analysis, bioassays are a powerful way to allow remote northern communities to examine their own water and determine for themselves if it acceptable. 

Reference Publications

  1. Edwards, K., Lund, C., Mitchell, S., Anderson, N., (2008). Trust the Process: Community-Based Researcher Partnerships. Alberta, Canada, Native Counselling Services of Alberta.
  2. Booth, l. A., Skelton, N. M. (2011) Improving First Nations’ participation in environmental assessment processes:  recommendations from the field. Impact Assessment and Project Appraisal, 29, 49–58
  3. Conrad, C. C., Hilchey, K. G. (2011) A review of citizen science and community-based environmental monitoring: issues and opportunities, Environ. Monit. Assess., 176, 273-291
  4. Conrad, C. C., Daoust, T. (2008) Community-based Monitoring Frameworks: Increasing the Effectiveness of Environmental Stewardship, Environ. Manage., 41, 358-366