Having a safe, resilient water supply is a luxury that, even in 2018, we cannot always count on. Issues ranging from water scarcity to compromised water quality continue to ravage the globe, recently hitting hard here in the United States. In early 2016, a state of emergency was declared in Flint, Michigan after lead levels in the local drinking water were deemed unsafe. The city switched to Flint River water in early 2014 as their water source, but the new supply caused lead to leach out of the aging water pipes and into the water itself. Despite citizen health complaints and independent agency warnings, it took over two years for governmental action. The Flint community was forced to use bottled water for cooking, drinking, and bathing but long-term health ramifications had already taken hold from heightened lead exposure. In September of 2017, Hurricane Harvey ravaged the Texas Gulf Coast. Many water and wastewater plants were flooded and damaged in the event causing compromised water drinking quality in many areas as well as fecal matter and harmful bacteria in the flood waters. In both these cases, giving the public the tools and knowledge to test and provide data on their home, work, or school water quality would have provided quick data to the local governments or plant operators allowing for a better understanding of the extent of the water quality problem.
This project, a collaboration between The University of Texas at Austin and The University of San Francisco de Quito (USFQ, Ecuador), was carried out in the Fall 2017 with the objective of engaging the community scientists (students in the undergraduate Introduction to Environmental Engineering course at UT, and students in the undergraduate "Environmental Engineering Fundamentals" at the USFQ) in a study to know the quality of their drinking water. A total of 100 students were introduced to the environmental, economic, and technical problems involved in the treatment, the distribution, and the quality measurement of drinking water.
Prior to initiating the project, students were given an anonymous pre-survey to establish their previous knowledge in the matter. The survey consisted of 11 total questions assessing the students’ knowledge about water quality and supply locally in Austin and Quito, water quality monitoring, and sample collection and analytical techniques.
When developing the project, it was important to take into consideration the interests of the collective students, to keep them engaged and interested throughout. Divided into groups, each group submitted a half-page abstract, designing an experiment detailing which water source they would test, why, and which parameters they would test for. Overall, the students tended to be interested in water sources they utilized in everyday life, such as campus drinking fountains, showers, or kitchen faucets. Taking their ideas and interests into consideration, a simple, yet hands-on and informative, experiment was developed to allow the students to test the water sources they were interested in. In Austin, half of the groups would be testing their kitchen faucets and half would be testing drinking fountains on campus. In Quito, half of the groups would be testing regular tap water (a small % of the population consider it safe to drink even though the quality is not bad), and half would be testing the newly installed drinking water fountains in campus (with a biological filtration system).
The overarching goal of the project was to compare water quality in samples taken immediately after opening the tap (first flush samples) to that in samples taken after running the tap for five minutes (purged samples). The following hypotheses were presented to the students to help guide their initial thinking:
1) Drinking water sources that are more frequently purged will have better water quality parameters than those that remain stagnant for longer periods of time (Quito and UT).
2) Water quality can be linked to the type of piping and where it is at in the distribution system (UT).
3) Chlorine residual present in the drinking water will be dependent on where it is located within the distribution system (less residual towards the end of the system; UT).
4) Newly installed fountains with filters will have better water quality than regular tap water (Quito).
A standardized procedure was developed to guide the students through each sampling activity and sampling kits were prepared and distributed. Each group took two total samples, the first flush sample (after the water system has not been used for approximately 12 hours) and the purged sample (after running the water for five minutes continuously). Each group was given a SureCheck Safety Test kit which allowed them to quickly and easily test the pH, total chlorine, and free chlorine of their samples.
An optional activity was also presented to the students allowing them to test for additional water quality parameters. Each group who participated was given a First Alert Drinking Water Test Kit, a home test kit that tests for additional parameters such as total nitrate, hardness, bacteria, lead and pesticides. This test kit is designed to quickly and easily test the quality of a potentially compromised drinking water supply. The goal of this optional activity was to have the participating groups evaluate their overall experience with using the kit and to suggest any improvements, keeping in mind the applicability of this kit to areas compromised by natural disasters. It is important to highlight that for research purposes, any positive given by this test would need to be double-checked in the lab. For example, the occurence of not pathogenic bacteria in water distribution systems is normal, and this kit would not differentiate if the positive result comes from pathogenic bacteria or from naturally occuring bacteria.
After sampling and in-situ analysis was complete, students brought their samples into the lab to run some additional analysis. Guided by experienced UT senior researchers and graduate students, each group ran an IDEXX Heterotrophic Plate Count (HPC) test as well as tested the conductivity and pH on a handheld meter. This component exposed the students to effective lab techniques as well as introducing them to simple lab safety and sanitation practices. Data from each groups’ in-situ and lab analyses was collected and distributed to the whole class for further analysis and interpretation.
Students at the USFQ testing their water samples
And the results are in! For both the water fountain and apartment tap samples, pH was around 9.3, not surprising for the Austin area. However, all these pH values were out of range for the SureCheck kit to read which tells us that these kits may not always be appropriate for testing the pH of drinking water. However, in Quito, the pH was ~6.5, and the kit measured 7.5 in average. Overall, the HPC values were higher for the first flush samples compared with the post-five-minute flush samples, suggesting that many sink and fountain piping appurtenances may have some degree of biofilm build-up and/or microorganism regrowth. The HPC values were much higher for the apartment samples compared to the water fountain samples, which was surprising given that many of the apartment tap samples were taken from newer apartments buildings. This may be attributed to frequency of use. The campus drinking fountains are likely used often throughout the day, while the apartment kitchen taps may only get used sporadically in the morning and evenings. Overall, all HPC values are well beneath the EPA maximum of 50,000 MPN/100 mL. The total and free chlorine values fell within the respective range set by the EPA and CDC. The EPA recommends a maximum of free and total chlorine of 4 mg/L to avoid negative taste or odor impacts and has no minimum standard. TCEQ recommends a minimum of 0.2 mg/L of free and 0.5 mg/L total chlorine for effective treatment. In Quito, two of the 6 groups reported positive values for biological growth (given by the First Alert Drinking Water Test, which does not indicate the bacteria detected were bad for humans). Chlorine levels in regular tap water were between 0.25 and 1.5 mg/L, within the recommended values. In the water fountains though, the levels were under 0.25 mg/l, not surprising given that the filtration system also captures the chlorine residual.
To finish out the project, students from UT were tasked with developing a written water quality assessment. Questions and hypotheses were previously provided to guide their thinking. Each group also developed a comprehensive infographic. The goal of the infographic is to convey the results of the water parameter testing in a format that can be easily understood by the public. Check out some of our talented students’ infographics (Fig. 1 and Fig. 2).
Figure 1. Infographic prepared by Juan R., Albert C., Zia L., Abby B., Jennifer R., Ashley B., Kresentia S., and Klarissa L., adapted by Rasmus and Maestre.
Figure 2. Infographic prepared by Sasha K., Wesley S., Jopert, Brice K., Syed A., Daniel D., and Pierre F., adapted by Rasmus and Maestre.
Throughout this project students learned invaluable techniques on how to assess water quality not only in a laboratory setting but with tools and kits available to the public as well. Many of these kits and testing methods are available at very low costs and distributing these to the public in affected areas would serve to provide a high volume of data in a short amount of time. Similarly, to the infographics created by the students, it is important to distribute information to a general audience that is easy to understand. Increased public awareness and involvement will make for better citizen scientists and a safer drinking water supply!
Thanks to Drs. Kerry Kinney and Navid Saleh for their support with the experiment design. Thanks to Stetson Rowles for helping with the lab analysis. Special thanks to Dr. JP Maestre for his guidance, and for providing invaluable input, support with the experimental design, and coordination and help from start to finish. Thanks to Melanie Valencia (USFQ) for her interest and collaboration in this project.
Information on the EPA Drinking Water Regulations can be found here.
Information on the TCEQ Drinking Water Regulations can be found here.
by Madison Rasmus, M.S. Candidate, Environmental and Water Resources Engineering.