This summer from June-July, 2019, Sara Glade, PhD Candidate, tested an arsenic treatment technology called ECAR (Electrochemical Arsenic Remediation) on a farm in Allensworth, California. Sara was accompanied by undergraduate Jay Majmudar, and with guidance and field assistance from PhD candidate Siva Bandaru, R&D engineer Dr. Mohit Nahata, and PI Dr. Ashok Gadgil.
The project started when an organic farmer in Allensworth reached out to the Gadgil lab in the winter of 2017. The farmer was facing arsenic contaminated groundwater on their farm, and wanted clean water for a livestock application. The Gadgil lab had previous experience in implementing ECAR in India and was interested in testing the technology further in the US context. The farmer donated water, electricity, and land so that the ECAR technology could be tested on their farm through a field trial.
A field trial is a great way to demonstrate a treatment process works before scaling it up to larger volumes. This field trial was designed to be a technology-test without offering the water for human consumption. The team wanted to conduct a field trial in Allensworth to improve the technology, test the technology in real world conditions in the US, and understand the potential of ECAR to solve arsenic issues in California, specifically agricultural and drinking water applications in small, low-income communities. Furthermore, the field trial can be considered as a stepping stone from experimental work towards a larger demonstration plant (plant at community scale) and eventual commercialization in the US.
ECAR works by using electricity to slowly dissolve an iron plate in water. The arsenic sticks to the resulting iron-rust in water. The rust then settles by gravity and/or by using an inexpensive, common chemical called alum to help settle faster. The arsenic-safe water is collected from the top. The iron sludge collected at the bottom is managed safely. ECAR has been used in India successfully at demonstration/pilot plant scale, and the team believes that ECAR has potential to be appropriate for challenges water systems in California face by having low operating cost, being easy to maintain, and having low capital cost.
In addition to studying technical aspects of ECAR during the field trial, Sara is working to conduct interviews with community members in Allensworth to better understand the social, economic, and political elements of technology development. Sara and Jay also conducted a two day session on topics including ECAR, water quality, engineering, and design for students from Alpaugh and Allensworth participating in a local Work Based Learning program.
The results are still being analyzed, but so far the researchers can say that the field trial was successful on many accounts! The next steps are to compile and share results to community members, to the general public, and to the research community. Beyond this, the team is hoping to find interested partners willing to work to develop and scale up the technology further.
Some pictures from the field:
