Water Samples: Tests and Real

     |    Monday, der 15. March 2010

The author of the following text is seen in the photo left taking a sample of riverbed sediment. David Vollrath is a political scientist. He was sent to Cajamarcain in northern Peru courtesy of the Welthaus Bielefeld mit dem Weltwärts-Programm des BMZ (“World House” is a development policy agency in Bielefeld Germany). He works for the non-governmental organization (NGO) GRUFIDES. In this report, David addresses the main conflicts surrounding mining projects, including severely dwindling or blocked waterways. What does the water quality at existing sources tell us, and how can the data be interpreted? The following is a somewhat shortened version of the original article. This and other articles can be read in their entirety (in German) on David’s Blog. (All photos by David Vollrath)


Water samples: Practice and For Real Cajamarca, November 24, 2009. A week ago on Sunday, Grufides offered a course on how to correctly take scientific water samples. A lovely organic country estate with a river, not far from Cajamarca, was chosen for the test site. Ten people from Grufides participated. First, the theory of sample taking was taught followed by practical instruction at the riverside. Chris is a Spanish chemist who wrote her doctorate in Peru about local water supplies and quality. So, in other words, she’s an expert.

Photo: Nonoy the assistant explains how it’s done

Chris closely supervised us as we practiced the proper method of taking water and sediment samples and doing rapid analysis. This wasn’t as pleasant as it sounds; the water was bloody cold and a swarm of mosquitoes were feasting on my bare legs. Strangely enough, I was the only one terrorized by the flying beasts while all the others were more or less spared. These mosquitoes are small, quick and nasty, and they left huge, very itchy red patches that plagued me for days. What one won’t suffer in the name of science.

Photo: Chris at the fiesta after the show.

After the work was done we enjoyed a meal of braised sheep and all kinds of different salads and sauces. Delicious, and the weather was beautiful! And since it was Sunday, Grufides’ director Mirtha ordered beers for us budding chemists. Test tubes of drinking water and half liter beakers for beer, the drinks were well alocated. The rest of the day was spent talking in the warm sun. A toast to science!

The following Friday I had a chance to put my new skills to the real test. The Comunidad Pajuela had asked us to take water samples from the last remaining river that still flows through the community. Valentin and I, with our smattering of knowledge, had batted ideas back and forth about the best way to go about the testing. We looked for sponsors as H2O-analysis isn’t cheap, that at least we did know, and we googled how one gets usable samples. Finally, we bought 350ml flasks at the pharmacy so that we could scoop out analyzable water samples. We had complicated plans on how we could get the samples to Germany so friend could test it with a home testing kit.

Photo: Ofe pokes around for sediment in this unappetizing soup.

Luckily, there was the Sunday instruction so I decided to announce our sophisticated plans, which raised a few laughs. Then Chris offered to accompany us and take her equipment to Pajuela so she could do proper samples. She also helped with the financing. She had money left over from a budget for water testing that she gets from her university in Barcelona. She could cover the costs for the Pajuela samples.

No sooner said than done. The following Friday we went to Pajuela. The campesinos were happy that we had an expert in tow. The sample-taking was just as we had learned: take five 1 liter bottles; rinse out the bottles three times before filling; take 3 sediment samples from different spots; mix to create one sample. Actually, you didn’t have to be an expert to know that the water from the Quebrada Cushuro isn’t completely kosher. It looks like a yellowish-brown stew flowing sluggishly over red-stained rocks. The results of first rapid analysis showed electrical conductivity of 1,250 instead of the normal 50-60 units (Sµ/cm).


Photo: Chris dipping samples