WATER QUALITY MEASUREMENTS
There have been a lot of requests for information on how groups can do their own water quality monitoring. Below are reliable and cost-effective methods that are straightforward enough for use by citizen scientists, but are also robust enough to produce reliable scientific data.
Electrical conductivity gives an indication of how much soluble ‘stuff’ is dissolved in the water. It can give an idea of increasing trends of pollutants, or spikes can indicate spill events.
Recommended: Hanna Instruments Dist 4 EC tester together with the Nitrate App/Deltares Aquality App
Cost: About R4200 once-off following which measurements are free. Requires calibration once in a while, and standards are provided when you buy the instrument. The App is free.
Nitrate can be an indication of sewage-polluted water or affected by other anthropogenic sources such as fertilizer and processing plants. It causes eutrophication and can also cause methemoglobinemia or blue-baby syndrome, when the blood is unable to carry sufficient oxygen.
Recommendation: Hach test strips (https://www.hach.com/p-nitrate-and-nitrite-test-strips/2745425) together with the Nitrate App/Deltares Aquality App
Cost: R32 per test. Requires a reference card (I can post you one) and the Deltares Nitrate App (free)
Phosphate causes eutrophication and is a clear indication of polluted water. This test involves a little bit of ‘wet chemistry’ but is simple to do and a very important pollutant to measure.
Recommended: Hanna Low Range Colorimeter (https://hanna-worldwide.com/industries/beer/hydroponics/water-treatment/drinking-water-treatment/phosphate/meters/hi713-phosphate-lr)
Cost: Instrument is R2200 then R24/test for the reagent
Strips are easy to use and the reading can be judged visually. The strips can also be used together with the StripScan App to get a more exact value. If you are interested in mine-affected waters (commonly called ‘acid mine drainage’) it may be worthwhile to also monitor sulfate(https://www.merckmillipore.com/ZA/en)
Recommended: Merck pH-indicator strips pH 0 - 14 Universal indicator. Can be used with MQuant StripScan App (free).
E. coli is an indicator organism used to screen for microbial contamination of water. High E. coli could indicate risks for infections with bacteria that cause typhoid fever, cholera, and dysentery.
Recommended: 3M Petrifilm E.coli/Coliform Count Plate test. Requires a 24h incubation time.
Cost: Approximately R25/test
There is a manual on how to do theses tests provided by the United Nations here. It also provides information on the use of the DEXX Colilert Presence/Absence test.
Climate change is expected to increase water temperature, with unknown effects on aquatic life.
Recommended: Can also be measured by the Hanna Instruments Dist 4 EC tester used for EC. It is recommended to capture the temperature in the notes section of the Nitrate App.
Cost: Free if you have the EC tester
All of the above can fit into a medium size toolbox making the kit very portable. We are currently using these test to monitor Hartbeespoort Dam water quality and the performance of an artificial wetland to filter grey water.
We are also working with IBM, Deltares and Texas A&M to produce useful interfaces for users to view their data on the web and to share data with others. The data will also link up with a hydrological model.
More information on obtaining historical water quality data from the Department of Water and Sanitation can be found here: https://www.waterresearchobservatory.org/data-and-resources/water-quality
#waterquality #citizenscience #Ecoli #EC #nitrate #phosphate #pH #watertemperature #testkit