Stepping off the bus at a wastewater reclamation plant, you expect to be in for a mundane tour. This tank is here, that pipe is there, this is what we do, here are our goals, any questions? No? Perfect, have a great day. That last thing you expect is the shear enthusiasm and depth of information we saw in the staff, especially tour guide Nancy Carr. Nancy began the tour with a historic overview of the plant, narrating the scope improvement from the first screening plant built in 1925 to a sophisticated facility with a three step sanitation process for LA’s waste water.
“When you use the restroom here, it’s a direct deposit.”
— Nancy Carr
The first step is “Headworks”, which consists of metal grate screens and sedimentation tanks to remove the big stuff that would compromise the subsequent processes. 15 tons of material is sent to a landfill each day from this first step. Primary processing thereafter involves coagulation of solids and the flotation of liquids which can then be skimmed off the top and bottom of the containment vessels. The solids are sent to biodigesters where bacterial growth is accelerated for the purpose of denitrification (can’t send nitrates into the ocean) and aerobic decomposition of organic solids. The activated sludge can be settled in the large clarifying tanks and these secondary solids can be sent for anaerobic digestion that produces methane, which is then used to power the facility, and biosolids which can be dewatered in giant centrifuges and used for fertilizer. In other words, as Nancy likes to say, they’re “running on [their] own poop”.
For water that makes it to tertiary treatment, cloth filters and polymers are used to remove any residual colloidal particles before discharge into the ocean or for non-potable re-use. Although this seems to be where it ends, there is much more infrastructure to be considered including the polymer and carbon air scrubbers used to alleviate foul smells from the surrounding community as well as all of the pipelines and sewers that bring the water to Hyperion.
The son of Uranus (Hyperion) Water Reclamation Facility employs around 370 employees ranging from laboratory scientists, to welders, to administrators in charge of safety, paychecks, and the like. While many of the scientists are involved in quality control and routine analysis, a team of engineers is involved in imagining the next stages in reducing liquid waste discharged into the ocean. As was mentioned on the tour, we have come a long way since we were still discharging raw sewage into the ocean back in the 50’s; these engineers are the ones who will be making today’s processes ancient history. While the infrastructure for past processes still exists on the site, the process of making infrastructure changes is a challenge and the facility can never stop working. Hopefully, sometime soon there will be groundbreaking on a complete water reuse facility.
Presently, the only allowed reuse of water from the plant is slated for those companies with permission to use non-potable water in industrial processes like cooling. In terms of solid waste reuse, its only use is fertilizer for a specific farm south of Bakersfield owned by the Los Angeles Department of Sanitation: Green Acres. At Green Acres, crops like corn and alfalfa are grown for animal consumption. While these are great steps toward FEWS solutions, there is a long way to go in terms of educating the public and government action before we can see better ones materialize. As people’s perspectives begin to change such that they are more accepting and embracing of new technologies and realize the urgency of the need for their implementation, even better solutions might be suggested. It might be possible that the fertilizer be usable even for crops meant for human consumption, and that it won’t need to be trucked so far off site for green usage. Maybe instead of only doing non-potable reuse a complete system will be in place for complete potable reuse of water. Lastly, maybe there will be introduced novel ideas for using the silt and inorganic matter that accumulated rather than having it trucked away to a landfill.
As INFEWS fellows, it is our job to look to the future and see how are careers might be directly related to solving these problems and implementing solutions. Right now, we can learn from this site tour and let it inform our decisions to make UCLA more sustainable.
Post and pictures submitted by Mackenzie Anderson and Patricia McNeil. This blog is part of the INFEWS social media series “FEW and Far Between”.
