Tuesday, October 24, 2017

Hayward Document Quotes on New Stinky Fish Hatchery

From documents on the City's Fish Hatchery "Transparency Page".  Its in black and white so no excuses for anyone now.




  • Building a wetland to filter nutrients, return clean water to the bay, and supply plants for future habitat restoration projects.
  • Conceptual site design includes indoor facility, stormwater ponds, storage pond for solids settling out, and treatment marsh.
  • Marsh and settlement ponds could be incorporated into the site usage with a boardwalk.
  • Waste removal: Round tanks with bottom-center drains concentrate waste. Fish waste includes solid waste, liquid waste (NH3), and gas waste (CO2).
  • Round tanks “self-clean” and are well-mixed. Rotational current around tank (primary current) affects radial flow (secondary current). Radial current transports wastes to center drain. Rotational flow dependent on water pumping rate.
  • Tank height and diameter ratio affects waste transport; about 3:1 height to diameter ratio is ideal. More fish produce more waste and need larger reconditioning systems. Amount of fish directs waste management plan. Waste removed continuously through mechanical pumping or biological removal, and solid waste filters that separate solids from water.
  • Solid waste removal: Filters are efficient at removing particles from water. Foam fractionators can remove very small particles.
  • Liquid waste removal: Fish produce ammonia (NH3) as liquid waste, which is toxic. Nitrifying bacteria use ammonia as food (nitrification).
  • NO3 is minimally toxic, used by marsh plants and anaerobic bacteria.

    • Nitrifiers grow in water, but need surface to adhere to and need a “biological filter.” Vessel/tank biofilter packed with highly porous material for nitrifying bacteria to colonize.
    • Gas waste (CO2) respired through gills, a fish metabolic end product. Negative effects on fish health if excess carbon dioxide acidifies the water. Forced gas ventilation of water with a “degassing box” increases gas exchange efficiency. Laminar flow passes water across trays and forces ambient air across the water and carries out the CO2.
    • Pumps (0.25-5 horsepower) are required to transport water and wastes.
      • High energy demand.
      • One-phase power or three-phase power.
      • Larger tanks with more fish require larger pumps, larger pipes, longer distance from tanks to filtration system, and more energy.

  • A large amount of O2 is critical to produce juvenile fish. High tech filtration works 24 hours a day. Largest water source, largest biomass, and largest amount of waste.
  • Wastewater management plan for tanks and also for discharge.

    • Solids, nitrogen, and approved chemicals for parasite removal if necessary.

  • Solids removed from effluent by ponds or tanks used to settle waste to the bottom or filtration systems that use concentration and remove waste to a drying area, then to a landfill.
  • For removing nitrate: 1) anaerobic bacteria nitrification, 2) marsh plants are a proven method with environmental benefits, or 3) sewer for specific small volume discharges only; depends on city, county and state permits required. An injection well is not a preferred method.

  • Just what we need downtown! 

    Hayward's legacy! The Prince of POO!


    2 comments:

    Anonymous said...

    Sounds like a really "crappy" plan. Exactly what we've grown accustomed to, more BS or in this case FS compliments of Mayor Feces or the Prince of Poo!

    Anonymous said...

    Million$ to make downtown smell like fish poop. Imagine the wonderful aroma during all of the weekend events. I wonder why no one else thought of this brilliant idea before? Maybe because it’s the dumbest idea in the history of ideas.