Ephemeral washes located in Southeastern Arizona, USA, contribute to large rivers like the San Pedro. For this reason, ephemeral washes are used by the Arizona Department of Environmental Quality (ADEQ) to gather data on contaminants like E. coli and suspended sediment which impact larger bodies of water downstream.
When a runoff event occurs, field scientists visit local wash sites to collect in-situ sample bottles. Any bottles containing significant samples of water are returned for analysis. The problem with this method is that field scientists spent too many hours hiking through dangerous conditions to check up on collection bottles. This resulted in unnecessary wear and tear to both equipment, and the field scientists themselves.
Hans Huth, a hydrologist with ADEQ’s Watershed Protection Unit, was looking for an easier way to check up on collection bottles. Though commercial GPRS modems and autosamplers could do the job, they were prohibitively costly.
Huth began his research into affordable open source alternatives, adopting the Arduino system and its wide variety of sensors. Huth built a solar powered prototype that sensed rain and water runoff and encased it in a waterproof kayaker’s lunchbox. A basic 2G GPRS modem was used to transmit sensor data to ThingSpeak, the IoT analytics platform that allows users to store, analyze, and visualize their data.
In order to deploy these remote environmental monitors (REM) in areas with no cellular connectivity, Hans worked with Sean Keane, an ADEQ intern, on reprogramming the Arduino to work with a RockBLOCK. For the purpose of monitoring discharges from a stocktank and to facilitate sample collection, a RockBLOCK-powered REM was successfully deployed at Horseshoe Draw near the border with Mexico. Given this success, ADEQ plans to deploy nine more cellular and RockBLOCK powered REMs throughout the state prior to the close of July, 2019. ADEQ is in the process of documenting time and money savings from respective deployments.
Huth documented his first environmental monitor’s development and deployment on YouTube to include links to source code for these inventions. Huth’s YouTube channel also includes chapters on building and deploying these REMs, and he is currently working on a new chapter summarizing code and deployment of RockBLOCK-enabled REMs.