Integrating water quality overview

How to integrate water quality testing into your programs
We are accustomed to hearing about the water crisis: 750 million people worldwide still lack access to an improved water source. But the water quality crisis is an even greater challenge that we have just begun to understand. 
Recent studies estimate that at least a quarter of ‘improved water sources’ are unsafe and that 1.8 billion people drink water that is contaminated with sewage. Fortunately, improvements in technology and testing methods make it simple and inexpensive to monitor and report water quality problems. We don’t need costly lab equipment or some new gadget to get accurate data on water quality — a few simple parts that anyone can buy will do. Here is how to get started measuring today water quality in your organization. 
Mwanza City Health Officers collect water samples from a piped kiosk
Mwanza City Health Officers collect water samples from a piped kiosk

What to test

While there are hundreds of chemicals that laboratories test for, there are a few basic parameters that matter most and these depend on the type of water you are measuring. For drinking water, the World Health Organization supports a critical parameter approach in low-resource regions that prioritizes tests for the most common contaminants. For most places the top priorities are E. coli (an indicator of fecal contamination, or raw sewage), arsenic, and fluoride due to the significant global health impacts of these contaminants. If the water is piped or treated, you can add chlorine to the list since the presence of residual chlorine is key in preventing recontamination.

Simple and low-cost tests

We suggest that you focus on methods that are currently available for purchase, are simple enough for non-experts to effectively use them, and have been validated in a field setting. Beware of claims made in the media or at conferences about some amazing new advance in water testing technology. It is important to realize that there are years of validation work required for something that might be promising in the laboratory or work as a prototype under ideal conditions to be ready for use in real water samples. The international aid community loves the idea of innovation, and often solutions are presented in the media without any scientific scrutiny because people want to believe that there is a better or cheaper solution. As always, if it sounds too good to be true, it just might be. That said, we are always on the lookout for new water testing technologies, so if you see something that sounds promising, let us know and we will look into it.

Chemical tests

We can divide the critical chemical parameters into two groups: easy, and somewhat easy. The easy ones can be measured using test strips. You may have used a pH strip in chemistry class years ago; same idea here. You dip the strip into the water sample and compare the color to a chart to get the reading. What test strips lose in terms of accuracy they often make up for in ease of use and low cost. They are getting better every year and now there is even a strip that is USEPA approved for chlorine. There are three main manufacturers of test strips: SenSafe (ITS), ETS (owned by Hach and also sold as AquaCheck), and LaMotte. You can also find some of these products online at Amazon.com or in local pool supply stores. Test strips can be used for the following critical parameters:
The somewhat easy chemical parameters require you to add one or more chemicals, called reagents, and then the result can be read using a color chart. None of these tests are hard; you just have to carefully follow the steps to get an accurate result. Also, some of these reagents are mildly toxic so make sure to follow the instructions for handling and disposal. Here are these parameters as well as some test kit options:
With chemical testing, it is always a good idea to buy a set of standard solutions that have a known amount of a particular chemical. They can can used to check that your method is working and are important for calibrating electrodes, which can drift over time.

Microbiological tests

Microbiological contaminants in water may include hundreds of different types of bacteria, virus, or protozoa — a diverse group indeed — so we tend to focus on a few indicators of sewage contamination. A good indicator should be usually be present in raw sewage (to avoid false negatives), not present in the environment (to avoid false positives), and not harmful to humans (since we will be growing billions of them in order to detect them). The WHO and most environmental regulators, including the USEPA, recommend E. coli as the best indicator for fecal contamination (another term for raw sewage). E. coli is most closely associated with diarrheal disease and is a component of the normal, healthy gut flora that live in our intestines. 
Thanks to fantastic scientific advances over the past 30 years, there are now very reliable and easy tests for E. coli. Most of these use defined substrate technology — meaning a chemical that only certain bacteria are able to use as a nutrient. When bacteria grow and reproduce, they take in the nutrient, causing a change in color. Even though the bacteria are incredible small (E. coli are 1 micron — a millionth of a meter — across), they double in population every 20 minutes. After about 18–24 hours of this exponential growth, there are enough bacteria (literally billions of them) for us to see the color change.
mWater sells a simple test kit for E. coli at two different levels, which correspond to the WHO recommended guidelines for drinking water and bathing (or wash) water. Our kit was inspired by NASA technology and was recently featured in the video below as an example of space technology benefiting life on earth. The kit is assembled from laboratory test supplies that have been repurposed for field work, so everything has been scientifically validated independently from our own testing. 
The mWater test kit was inspired by technology used by NASA on the International Space Station, which has constraints that are similar to those found in low resource regions
There are other options, including the Aquagenx compartment bag test and the Idexx Colilert test, that you can use to reliably measure E. coli with a minimum amount of training. We support other types of tests in the mWater Surveyor, since our goal is to make water quality data easy to share. You can start using the mWater Surveyor for free right now, using our Standard Drinking Water Test form, which has data entry options for many different tests and parameters.

When and where to test

It is important to measure water quality both at the point of collection and the point of use, meaning in the household where people are drinking. Recent testing in Nepal by UNICEF revealed that 81% of household stored water contained measurable E. coli. No matter what you do to provide clean water at a community water point, there will always be a risk of contamination during transport and storage. If people are still drinking unsafe water in their homes then all of the investment made in providing treated water could be lost due to storage and hygiene conditions in the home. 
A good approach for small water supply systems, such as boreholes or shallow wells, would be to test at least 2 different times per year at the source and at a random selection of several households who obtain their water from that source. At the household, ask if you can sample the water that they would give to a household member to drink. This helps prevent courtesy bias, where the household might give you bottled water or some other better source because you are a guest. 
As the number of people using the water source increases, so does the risk of a disease outbreak from that single source. Therefore, you should conduct more frequent testing depending on the number of people using the water system. The WHO has some useful guidelines for sampling frequency in Table 4.4 of their Guidelines for Drinking-water Quality. The key parameter for larger systems is not the amount of E. coli in any one sample, which should generally be very low, but rather the number of samples that come back positive. Active outbreaks of acute diarrheal disease such as cholera can be reduced with more constant monitoring. While cholera test results are more expensive and require a lab, E. coli is a useful indicator of any water source that might be at risk of spreading cholera, as cholera is transmitted when sewage enters water supplies. 

Communicate the results

A critical step that many organizations miss is closing the feedback loop by communicating water quality to the end users. In our own work in Tanzania, we found that conducting the water test at the water source helped create a demand for knowledge surrounding the results. Crowds often gather around the health worker or water manager conducting the test, which becomes an opportunity to talk about water safety. Once we observed this, we made sure we added the step of sending our water tester back out to the water source to let the users know the results. The mWater test kit (and some others) change color visibly with a positive test, making it easier to explain the otherwise invisible bacteria that makes a water source dangerous. 
Many mWater partners, like Ugandan Water Project, are committed to regular water quality testing and making the results public
The mWater test and many others cover a range from very contaminated water that is not even safe to bathe or wash in, to water that is safe for all purposes except drinking. The survivors’ bias effect means people who survived a contaminated water source past the age of five will always think it survivable. It is useful then to talk about the critical role of safe water in children’s physical and mental development. Unsafe water is a leading cause of stunting in children. If a household only has enough treated water for drinking purposes, be sure to explain not to mix up the containers used to transport wash-safe water and drink-safe water.

Turning results into action

Beyond communicating results to the public, it is important to let the data from water quality testing advise policy decisions. Our work with the city government in Mwanza, Tanzania, showed widespread contamination of shallow wells regardless of their age or sanitary condition. Equipped with this data, the city made a policy decision to not certify construction of shallow wells anymore, but rather encourage NGOs to build safer boreholes or extend the piped network with a kiosk or public tap. Many NGOs we work with similarly are changing their practice from installing the cheaper and easier shallow wells to more expensive boreholes based on the results of initial water quality tests. 
The movement toward regular water quality testing is not an easy transition for our sector. In almost every location we have assisted with a region-wide or nation-wide map-and-test activity, the results showed upwards of 80% of water sources were contaminated with E. coli. This does not mean safe water is unattainable, but rather that progress will be hard fought. We find it helpful to begin with the goal of creating and protecting one potable water source per community and labeling it “Baby Safe” water. This helps families with the most vulnerable population to unsafe water, young children, make the choice that is safest for them, despite the older population’s reluctance to change old habits. 
mWater is building an open access database of water quality data through individual users and organizations who choose to share their data. We encourage you to make your data “protected” or “public” in mWater so that others can see your work. Progress and knowledge will grow faster with collaborations among NGOs and between the aid and government sectors. 

For more information on beginning mapping, testing, or monitoring water and sanitation, please contact us at info@mWater.co. 
This data-driven post was created using the mWater portal. Click here to learn more about how to create dashboards, maps, and pages to tell stories with data.