The Waste Dump!

For the past week my group, (Sebastian, Carmen and Ellen), has been working hard on our small project at the waste dump. We are trying to determine the extent and direction of the plume of contaminated water that is being produced by the waste dump. We have installed piezometers to determine the waterlevels (and groundwater flow directions) and to take samples for chemical analysis.The 7+ meter hole is finally dug! What a relief!


Now all that's left is getting the auger out........

And putting the piezometer in.......

We also walked several EM34 sections (measurement with 2 rings that emit electromagnetic waves; allows you to look at the layering in the subsurface (different sediments, contamination)). And we did some EM39 measurements. This instruments works the same as the EM34, only it is designed to go down a borehole and gives you precise conductivities of each layer of sediment.

There were several lakes near/in the waste dump, two of which were not contaminated and one which was full of waste. We measured the amount of oxygen in the dirty lake and it was very close to zero. The only inhabitants of the lake were huge crabs and lobsters.


After many long days of hard work, we are happy to have an idea about where the plume is going. But spending too much time at a waste dump can do crazy things to people at the end of the day.....

Cheers, Ellen

Surprise

While we were making plans for the fieldday of yesterday, Maarten called to tell us we should go to the island! We didn´t expect to go there anymore, so that was a surprise! The little birds were still there so we only could get there for half an our to get the diver which was installed the week before.

A fisherman brought us to the island, and back to Costa Nova

We installed the diver from the island in one of our own piezometers. The day before we tried to speak with some local mini Portugues people. With Maarten it was possible to have a conversation and he asked if they wanted to be photographed with us... And this is the result!


Roos-Anne & Inge

Meanwhile, on the beach...

The second part of our bachelor thesis is a groundwater study between Ria the Aveiro and the sea. Before we could start this study we had to find out where the best place along the coast is, where the dunes and the lagune are not too far from each other and where’s space enough to use the Electro-Magnetic methods. We had to wait for the bus of Maarten and Boris with all the materials. And this seems to be the perfect place.

Andreas, Jeremy and Roos-Anne. Fieldwork = hard working...
To find out where the fresh water is and how the fresh and salt groundwater move during the tides we drilled two piezometers, one near a freshwater well in a field next to the dunes and one near the river.

Roos-Anne drilling a hole for the piezometer near the freshwater well.
These piezometers can be used for different kind of measurements this year, but also next year, the year after etc. We make two more piezometers this week to find out where the fresh water comes from.

Finishing a piezometer near the Ria.
With the EM-39, an electromagnetic method, the conductivity of the water is measured. The EM-39 had to be calibrated.

Maarten as the Statue of Liberty, calibrating the EM-39.
Tomorrow we probably will do a measurement at the beach with Boris, so we can make a profile of the groundwater from the beach to the dunes, the field ending at the river. Still enough research to do...

Ciao, Roos-Anne & Inge

Rainfall - runoff madness...

It finally rained today..! After two weeks of great weather we could get new surface water data this morning. I am used to standing in the rain and getting cold while collecting these data, but our students were lucky. Rainfall stopped at dawn and the only inconvenience was the mud on our feet.


I went out with Robert, Pieter and Achille to take some samples of rainfall in their area and to do discharge measurements in the - now swollen - streams. This is allways a bit of a frantic process as the water level changes fast and 10 students want to measure discharge at the same time with the same instrument...


We also took some samples of the river water, which was pretty muddy as compared to before.


After lunch in Montouro, we ended up in some agricultural field of an old lady, who had given permission to place a raingauge there. People start to know us now and we get invited for drinks and to see their baby pigs!


Posted by Maarten Waterloo

Vagueira beach groundwater: where is the salt...?

Last week one of our students had to leave early because of family health problems, we all wish him a lot of strength for the coming period. The work here continues... We got our water samples transported to Holland and are now concentrating on geophysics and special investigations. So Boris got lucky again and went to the beach yesterday with Jeremy, Diego, Roos-Anne, Inge and Andreas. Not to get more tan or to surf, but to investigate fresh and salt water in the beach soil. We use geophysics to study this and its a nice change from our smelly garbage dump project where we had been the past days...


Today, I got the more demanding task to make a groundwater monitoring well together with Andreas, Roos-Anne and Ingrid. As I am the heavy weight in this group, I had to do a lot of bailing to get the sand out of the well casing, while they turned me around (what's he talking about...?). We got to about 6.5 m deep down to a gravel layer, which forced us to stop. Good for me because I still feel my muscles ache from the heavy work.


Anyway, tomorrow we are going back to Vagueira beach to do some more measurements. Less demanding ones, that is. Geaophysics again and perhaps we'll make a shallow well near the estuary. We expect some rain the coming days and that will give some activity to measure stream discharge and collect rainfall samples.

Posted by Maarten Waterloo

The island study...

Today was a bit of a crazy day. I had to go to the hospital with Diego who had hurt himself while playing soccer yesterday, but it turned out OK. Just a bit of cleaning of the wound on his hand and some anti-biotics. In the afternoon we suddenly had some time to spare and as we had planned to start the island study today, me, Boris and Diego decided to go to the island and install some divers (these measure the waterlevel, temperature and electrical conductivity) in the piezometers that we placed there last year.

The island study is about the freshwater lens that develops on the salt water in the subsoil of the island by infiltration of rainfall. We use hydrochemistry and geophysics to study its development and changes with the tides. Of course, another reason is that it is nice to have a boat trip, work on a small island, get your feet wet and watch the fishermen go by!


Doing this island study involves a trip to the fishermen's harbour in Costa Nova by car, asking one of the friendly fishermen (in this case Adriano) to bring us there and trying to find the groundwater tubes, that were buried invisibly in the sand. The sand was very hot and we danced around a little bit on our bare feet before we found them. We installed the divers and went back to the sea too cool our feet. Then back to Costa Nova for a good coffee. Next visit will be to download the data.

Tomorrow we are going to install groundwater tubes to study contamination of the groundwater from an illegal, rather smelly, garbage dump in a nature area. The things you have to do as a hydrologist...

Posted by Maarten Waterloo

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