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Name Austin Anderson
Affiliations Cal Poly Humboldt
Registered 2017
Impact 662
Contributions CCAT greywater 2017

I think the Spring 2017 Greywater team deserves an A+ on our project, and I’m not just saying that. Each member put in over 60 hours of personal time. I ended up directly spending 65 hours on the greywater renovation, not including the countless times this project invaded my everyday thoughts and daydreams. We tackled unique challenges in unique ways and faced down failure multiple times but continued to persevere until we had a functional system.


As an employee of CCAT for 2 years I have been part of many of the frustrating conversations about the greywater marsh. The fact that the settling tank is surrounded on three sides by impermeable surfaces (with the fourth side being inclined garden terraces) made it abundantly clear that there was going to need to be some sort of pump. I found this great video on YouTube of a British guy making an awesome hand pump using PVC pipe, wood, and decades of carpentry experience. The team felt that having a hand-made hand pump providing greywater to a bathtub demonstration would showcase two forms of appropriate technology. Unfortunately, after weeks of testing the hand pump never materialized (we just weren’t good enough carpenters/craftspeople, which is fine). It was 8 weeks before the project was due when we decided that we needed to look into a manufactured pump system. This presented a unique problem


I spent hours researching pumps that could be submerged (in greywater), could handle greywater nastiness including solid waste and oils, and possibly be powered directly by solar power or by the MEOW. I realized that a DC trash pump that met all of these qualifications existed but would be cost prohibitive for this project. I then found an electric pump that was cheap (~$100) and was designed to be submerged, it was also able to deal with solids in our size range. Seemed like I had found the best option, unfortunately in the literature it was explicitly stated in all caps that this pump should not be plugged into an extension cord because it could damage the pump. The more I thought about it as a CCAT Co-Director the less that I liked the idea of putting an expensive pump into a greywater system that is already neglected by an organization that lacks institutional memory and faces constant turnover of employees. I then thought about merging the idea of manufactured pumps with our initial idea of hand pumps and we were able to solve our pump issue.


Rotary drum pumps are used predominantly used for bringing oil out of barrels. These pumps are even cheaper ($40) than our previous cheap option and were proven to work so we decided to pull the trigger and order a cast iron, hand crank, rotary drum pump. The kit can with two 1’ lengths of metal pipe which we attached 4’ of PVC to and a screen. After making sure all the pipes were sealed we were able to bring greywater up to the rest of our system. Systems are comprised of individual parts and in the same way that the pump is just one aspect of our marsh, I was but one piece of the amazing team that really took on the challenge of CCAT’s greywater system in a unique and creative way. The team consisted of Cassidy Barrientos, Alex Christie, Jenna Kelmser, and me. Cassidy focused on the design of the tub, Alex focused on how to fix the existing hole, Jenna focused on marsh plant maintenance and end use, and I focused on the pump. We were able to effectively split up tasks and work as a team on site almost every Sunday and Thursday of the semester. I sincerely believe that this entire team deserves A+’s, we put our all into it and got an amazing result!!

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