How Clean is Sewage after Treatment

Introduction

Sewage clean up services play a vital role in maintaining the health of our communities by properly disposing of and treating wastewater. Sewage treatment plants employ various processes to remove harmful contaminants and pathogens from raw sewage.


Sewage Treatment

Primary Treatment

  • Involves the physical removal of solid particles and debris through screening and sedimentation.
  • Primary treatment can remove up to 60% of suspended solids and 30% of biochemical oxygen demand (BOD).

Secondary Treatment

  • Utilizes biological processes to further break down organic matter in sewage.
  • Bacteria and other microorganisms consume organic pollutants in an aerobic (with oxygen) or anaerobic (without oxygen) environment.
  • Secondary treatment can remove up to 90% of BOD and suspended solids.

Tertiary Treatment

  • Additional processes beyond secondary treatment that provide further purification.
  • Methods may include filtration, disinfection, and nutrient removal.
  • Tertiary treatment removes remaining contaminants and enhances water quality for various uses, such as irrigation and industrial purposes.

How Clean is Water After Sewage Treatment?

The effectiveness of sewage treatment in purifying water depends on several factors, including the specific treatment processes employed and the influent quality of the raw sewage.

After treatment, the water discharged from sewage treatment plants typically meets established regulatory standards for water quality. These standards ensure that the water is safe for release into the environment and poses minimal risks to human health and aquatic life.

Advanced treatment technologies, such as membrane filtration and ultraviolet disinfection, can further improve water quality and remove emerging contaminants that may not be effectively removed by conventional treatment methods.

It is important to note that while sewage treatment processes are highly effective, trace amounts of pollutants may still remain in the treated water. These pollutants may include low levels of nutrients, pathogens, and pharmaceuticals.

Therefore, treated sewage water should not be considered as pristine drinking water and should not be consumed without further purification or disinfection.