Groundwater Monitoring: What’s Winter Field Work Like?
-Kyla Grasso, Geologist, AltaRock Energy, Inc.
Although the stimulation phase of the Newberry EGS Demonstration has come to a close, field work continues throughout the winter months on the volcano (brrr!). We’re currently collecting and analyzing groundwater samples in order to monitor any changes in the local groundwater system. This work is intended to make sure thestimulation hasn’t affected the quality of the groundwater high on the flanks of the volcano. Water samples are collected by AltaRock’s staff monthly and sent to independent laboratories where they’re analyzed for 30 different elements. Characterization of the local groundwater chemistry means we’re able to show that EGS can be developed safely and without negative impact on the surrounding aquifers and hydrologic features.
We will continue to collect and analyzing water samples from several sites surrounding the stimulation well for six months following the stimulation. Sample sites are located both up-gradient and down-gradient from the stimulation well. In the winter we sample the hot springs at East Lake and Paulina Lake in Newberry Caldera, two wells located on the volcano, and a residential well in the valley. Once spring weather comes around (we’ll hedge our bets on mid-July, since last year it snowed June 26th!), we’ll be able to access several other wells which are shut in for winter to protect them from freezing. So what does groundwater quality sampling look like in the field? Check out these photos!
Field work in the winter months is always tricky. Newberry Volcano often hosts 5-6 feet of snow, making a tracked vehicle and snowshoes must-haves for winter field
work. Collecting just two samples can take an entire 10-12 hour field day if all goes well. We’ve all heard the phrase, “an ounce of prevention is worth a pound of cure”, and when it comes to working in an environment where temperatures can range from -15 °F 100 °F, that couldn’t be more true. While we’re out sampling groundwater, we often make time to check on seismic equipment, perform any needed maintenance and make a stop at the stimulation well to check on things.
Each sample collected is first analyzed in the field. We record pH, water temperature, electrical conductivity and a number of other measurements as soon as we take the sample. Once these are recorded, the water is filtered, bottled and sealed to prevent contamination before being sent for analysis. Three laboratories perform more than 30 different tests on each sample. Our staff compiles the data, compares it with previous results, and looks for any significant changes.
So far we’ve collected and analyzed 21 samples from nine different sites surrounding the stimulation well, and we’ll head out again next week to collect another set. Our sampling program can detect changes as small as 0.2 parts per million for some elements. As expected,
to date no significant changes to water quality have been found at any of the sampling sites.