Hyperion Treatment Plant Flowcharts: Navigating Wastewater Transformation
Wastewater comes to the Hyperion Treatment Plant via the sewer system. Most of it comes from inside houses; from sinks, dishwashers, bathtubs, toilets and washing machines. Some of the water that is treated at Hyperion comes from commercial and industrial users.
The first materials removed from wastewater are the most noticeable ones; like wood, sticks, plastic and rags. Bar screens let the liquid flow through, but stop the big objects. Sedimentation tanks are then used to capture sand and other gritty solids. Fifteen tons of these solids are removed and driven to landfills every day. Wastewater continues to primary treatment.
The wastewater now flows slowly through under– ground tanks that are the size of football fields (it takes one hour). Chemicals, called coagulants, are added to help solids that are suspended in the water settle to the bottom. The solids are then pumped to the digesters for further processing. Oil and grease are also skimmed off the top of the wastewater. The wastewater flows to its next level of treatment: Secondary Treatment.
Nature's tiny decomposers are now called upon to remove the organic materials that are left in the water after primary treatment. These microorganisms thrive and multiply when given plenty of oxygen and 'food' (the organic solids in wastewater). Several hundred tons of microorganisms are mixed with wastewater and oxygen in oxygen reactors for one to two hours. A special 'Cryogenic Air System' is used to separate oxygen from other gasses in the air and concentrate it to provide our decomposers with 96% pure oxygen.
Settling, Clarifying Tanks
Once the organic food is depleted, the secondary wastewater flows into clarifying tanks. It stays here for four hours while the biological solids - tons of microorganisms - settle to the bottom. By this time, 90-95% of the solids in the wastewater have been removed and the effluent (treated wastewater) is clean enough to enter the Santa Monica Bay or be recycled. The biological solids that have settled to the bottom are now pumped through a separate piping system and some head to their next level of treatment: the digesters. Most are recirculated back into the oxygen reactors to continue biological treatment.
Effluent Disposal and Reuse
Most of the secondary treated effluent is discharged into the Santa Monica Bay through a pipeline that goes five miles out from the shore and is 190 feet deep. At this distance and depth, the water does not return to the shore. The discharged effluent has plenty of oxygen and is blended with Bay waters. About 6% of the cleaned water is pumped to a water reclamation plant where it's run through another level of treatment and used to irrigate golf courses and parks and to provide industrial water to local businesses. A small amount of water returns to Hyperion where it is used at the plant for cooling water, irrigation and chemical dilution.
Again, we call on Mother Nature to help us. This time to destroy the disease causing organisms (pathogens) in the biosolids. The solids that were removed from primary and secondary treatment are now pumped into huge, totally enclosed, egg shaped tanks called digesters. Bacteria and other microorganisms that live without oxygen, thrive here. It takes about 15 days for these microorganisms to eat half of the biosolids, destroy the pathogens, and release a natural methane gas that has tremendous energy value.
Biosolids are very watery when they leave the digesters. To lower transportation costs, we reduce the amount of water in the biosolids by sending them through a centrifuge. It acts like the spin cycle of a washing machine and removes one-forth of the water. The biosolids now have the consistency of toothpaste and are ready for transportation to their beneficial reuse location.
Methane gas that is produced during digestion is captured and piped to a nearby power plant. In exchange for the gas, Hyperion purchases power from the power plant at a reduced price. In a sense, Hyperion is now powered by its own biosolids!