Last Friday I spent my day hidden in the Puijo forest. Purpose was to finalize the purging of the groundwater monitoring well. The basis for purging is the assumption that the groundwater standing in the well is not representative of the groundwater in the surrounding aquifer. Also there was some clay in the water.
Weather and conditions was typical i.e. chilly, some rain and ground was covered with thin layer of wet snow. Road was little bit slippery as you may see from the photos (below). I survived but there was no need to go to the gym after the work.
Groundwater was still turbid and kind of muddy. Inertia pump was used and after accurate volymetric measurements, the pump flow rate was 4,8 litres/minute with "full speed mode". Water level in the well was +100.10 meters (2.44 meters below the well top). Thus, there was 11.40 litres water in well. During pumping I noticed that groundwater was flowing into a well quite rapidly. Pump was efficient enough to empty all the water from the well, after that it took about 10 minutes to fill up. At the end of pumping fill up time was much more longer. So, I pumped 15 minutes, waited 10 minutes and pumped 15 minutes, and so on. Finally fill up time was so long that pumping was stopped. I think over 500 litres of water was pumped out of the well.
After all, the groundwater was little bit clearer but still turbid and muddy. That grey stuff in the picture came out of the well. There is at least two options how to proceed:
- Use the lake water and more powerful suction pumps to continue purging
- Use the filtration when groundwater samples are taken. This is actually recommended procedure.
Perhaps we try both of these options in order to purge the well and to evaluate quality of groundwater. Okay, no clear water yet but at least I got loads of fresh air and some muscular training... both are needed!
Teemu
Comments
Post a Comment