Wastewater Treatment

The pollution of our living waters cause a considerable environmental problem all around the world. The main sources of pollution are the industry, agriculture and population. For the purpose of protecting our living waters, the primarily applied technology is wastewater treatment, whose main goal is to prevent the arrival of polluting matters in the environment.

51% of sewage of Budapest generated in dry periods are treated at the North-Pest and South-Pest plants, whose joint nominal capacity reaches 235 thousand m3/day. The South-Pest treatment plant has a biological treatment capacity of 80 thousand m3 and a nutrient removal capacity of 80 thousand m3. The North-Pest plant treats 155 thousand m3 wastewater a day on average, but from time to time, this quantity reaches 200 thousand m3.

We apply physical, biological and chemical methods to treat wastewater:

  • We catch the matters rolled at the bottom of the sewer through grit collector;
  • We filter the bigger size floating matters via screens;
  • We settle out sand in sand collector;
  • We separate fats and oils in fat collector;
  • We add chemicals to expel phosphorous;
  • We settle the organic floating matters in primary clarifier;
  • We degrade the solute organic matter in activated sludge aeration basins;
  • We separate the treated water from the activated sludge in secondary clarifier;
  • We densify the sludge removed from the primary clarifier, develop biogas from it and dewater it;
  • With the use of the produced biogas we produce electric energy;
  • We use our solid waste in agriculture or dispose of them in landfills. 
    Sewer work waste

During the operation of the sewer works, waste is created of which disposal must be taken care of according to the environmental prescriptions and the obtained authorizations. The dehydration of the deposits removed during sewer cleaning is done at the South-Pest plant. This, as well as the dehydrated sand trap deposits and grid waste of smaller pump stations is collected at the South-Pest plant and then transported away. The dewatered sand collector sediments and grid waste of bigger pump stations is transported from the pump stations directly to the receiving company.

Among solid waste, grid waste and sand collector sediments is disinfected and disposed of in landfills or treated with composting processes with the contribution of external companies. The sludge of the North-Pest Wastewater Treatment Plant is put in landfills, while the sludge created at the South-Pest Wastewater Treatment Plant is used in agriculture after compostation or also transported in landfills. 

In some fields, Hungarian authorities prescribed requirements already much more severe than the European Union thresholds for wastewater treatment plants, thus FCSM has already been producing water that is significantly cleaner at its treatment plants. 

The authorities have set the following thresholds for already operating treatment plants (compared to EU requirements):

Parameter Threshold required by the EU South-Pest plant requirement North-Pest plant requirement
COD (chemical oxygen demand) 125 mg/l 50 mg/l 75 mg/l
BOD5 (biological oxygen demand) 25 mg/l 10 mg/l - mg/l
Floating matter 35 mg/l  35 mg/l 100 mg/l


Naturally, apart from those listed, there are thresholds for numerous other chemical components as well, whose respect is regularly controlled by the relevant authorities.