The fonte study...

Yesterday our BSc students started their research. We discussed their projects (they do "fonte" and "small island freshwater lens" studies) and went on to sample the first fonte. Fonte is Portuguese for a water source, or a place where people have public access to water and that is maintained by the city. These are usually natural springs that have been used for ages before piped water became common in the houses. We started out at the Fonte Juncal (see picture below). It gets its water from a pine forest on sandy soil several hundreds of meters away.


Boris demonstrated Inge and Roos-Anne how to calibrate the pH meter an measure pH, measure the electrical conductivity and temperature of the water, analyse for nitrate and bicarbonate, and take filtered samples for lab analysis of chemistry and isotopes.

It was already lunchtime and a lot of old Portuguese ladies, who had been working in the potato fields, passed with bottles to collect water from the fonte. I asked them if they did not have piped water at home. They do, but because that water is treated they prefer the fonte water with their meals, as it has a much better taste. The water quality of this fonte is good, but there are several with high nitrate and I hope that that doesn't give health problems. As these fontes get their water from shallow, non-protected aquifers, they are very liable to contamination (mostly nitrate from use of fertiliser). Good that we do an annual check of the water quality...

Posted by Maarten Waterloo