Filtering mechanism used for analysis (IMAGE) Geological Society of America Caption Filtering mechanism used to pump water from the splash pool for analysis of microbial communities within the pool. Old Faithful geyser cone can be seen directly behind the filtration setup. Permit number #5544. Credit Lisa M. Keller Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. License CC BY-NC Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.