Ecological septic tank. What is it and how it works

Ecological septic tank

What is an ecological septic tank and how does it work?

An ecological septic tank is a large container used for treating domestic wastewater. It plays a crucial role in wastewater collection in homes and buildings, especially in areas without nearby sewage networks, such as rural areas or single-family residential zones.

This article explores the ecological septic tank, differentiating it from traditional septic systems.

Difference Between Ecological and Traditional Septic Tanks

An ecological septic tank is defined by its biological filter, distinguishing it from traditional septic systems in the treatment of black water (sewage). Increasingly popular, ecological septic tanks pose no risk of soil contamination and do not pollute groundwater, thereby eliminating unpleasant odors and being environmentally friendly.

In summary, an ecological septic tank offers the same functionality as a traditional one but with significantly less pollution.

Sanitation Goal an Ecological Septic Tank

The primary ecological sanitation goals of an ecological septic tank are:

  • Reducing health risks from waste and contaminated water.
  • Preventing soil fertility loss.
  • Preventing contamination of both surface and groundwater.
  • Optimizing water resources and nutrient management.

How an Ecological Septic Tank Works

Firstly, waste from bathrooms is deposited in a tank, about 30 meters from the house, made of materials ensuring safety, durability, and resistance. This tank has a vent for gas release.

Secondly, physical sedimentation occurs where solid waste settles at the bottom for decomposition.

After decomposition, as the tank fills, the liquid moves from the top to the bottom, passing through rock, gravel, and sand filters.

Finally, after filtration, the liquid is stored in another tank, called a soakaway, where it is either reused or returned to the environment.

Considerations for Ecological Septic Tanks:

  • When installed underground, tank covers should not be too large to prevent collapse.
  • Tank size depends on the number of residents.
  • Wastewater from sinks and drains should not mix with septic tank waste, as cleaning chemicals can disrupt decomposition by killing bacteria.

Why Choose an Ecological Septic Tank?

Reasons to opt for an ecological septic tank include:

  • Ensuring soil fertility.
  • Improving agricultural efficiency and food security.
  • Enhancing health by minimizing pathogen introduction from human waste into the water cycle.
  • Preventing contamination of water and soil.
  • Reusing water for agriculture, plant irrigation, and aquifer recharge.
  • Recovering nutrients from feces for use as soil fertilizers.


Regulations Governing Septic Tanks

According to environmental protection directives, ecological septic tanks in the European Community, like traditional ones, must adhere to specific regulations.

They require periodic inspection and emptying, depending on their characteristics, location, and design. Removal of contents must be done by certified and authorized specialized companies.

Waste must be processed at appropriate facilities as per legislation, typically at a treatment plant. Final waste disposal is also regulated by official legislation.

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