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Seeley County Water District Wastewater Treatment Plant Upgrade Project

A Membrane Bioreactor or MBR System for Wastewater was selected as the preferred alternative over a Biolac Wastewater System, and the design was advanced to sixty percent.   In April 2022  an amendment to the agreement was submitted to the State Water Resources Control Board  (SWRCB), this is mainly because because construction costs have escalated significantly over the last few years due to supply chain and labor shortages, and the funding level in the Agreement was developed in 2018 based on preliminary information.
Here's a general list of potential items for improvement at a wastewater treatment facility:

  1. Conversions of the Clemson Ponds to flow equalization
  2. Modifications to the Lagoon Pump Station
  3. Two MBR secondary treatment system packages 
  4. Solids handling, including mechanical dewatering and upgrades to the sludge drying beds
  5. New Operations Building

What  is a MBR:  A membrane bioreactor (MBR) is an advanced wastewater treatment technology that combines two essential components: a bioreactor and a membrane filtration system. MBRs are commonly used in both municipal and industrial wastewater treatment plants (WWTPs) to achieve higher effluent quality and more efficient solids removal compared to conventional treatment methods.

Here's how an MBR works:

  1. Bioreactor: The bioreactor component of an MBR is similar to a traditional activated sludge system. In this part of the process, microorganisms (bacteria and other microbes) are used to break down and consume organic matter and pollutants present in the wastewater. This biological treatment stage is essential for reducing biochemical oxygen demand (BOD), removing nutrients, and degrading organic contaminants.
  2. Membrane Filtration: The key innovation in MBR technology is the use of a microfiltration or ultrafiltration membrane unit. This membrane acts as a physical barrier with very small pore sizes, typically in the range of micrometers, preventing the passage of suspended solids, bacteria, and pathogens. The membrane effectively separates treated water from the biomass (microorganisms) and solid particles present in the bioreactor.

The combination of the bioreactor and the membrane filtration system in an MBR provides several advantages:

  • High-Quality Effluent: MBRs produce high-quality treated water with very low levels of suspended solids and pathogens, making it suitable for discharge into sensitive ecosystems or for water reuse applications.
  • Compact Design: MBRs often have a smaller footprint compared to conventional wastewater treatment systems because they eliminate the need for secondary settling tanks.
  • Improved Solids Separation: The membrane barrier ensures efficient solids separation, resulting in reduced sludge production and better solids retention in the bioreactor.
  • Flexible Operation: MBRs can handle variations in influent flow and load more effectively than some other treatment methods due to the membrane's ability to maintain a consistent barrier.