272 पटक हेरिएको 
Kathmandu: Whether at home, school, office, or public toilet, one small yet extremely important structure is often overlooked in septic tanks the vent pipe. Many people assume, “The tank is built, the work is done.” However, this mindset can lead to serious health, safety, and structural problems in the future.
As human waste decomposes in a septic tank, gases such as methane and hydrogen sulfide both flammable and toxic are naturally produced. The vent pipe safely releases these gases outside. But what happens if there is no vent pipe?
1. Risk of Explosion Due to Gas Accumulation
Without a vent pipe, gases accumulate inside the septic tank, increasing pressure. Experts warn that this can cause the tank lid to blow off, the tank to crack or burst, and in some cases, an explosion if exposed to fire. This risk is especially dangerous in densely populated areas, hospitals, and schools. Recently, experts emphasized this risk during an interaction program with sanitation workers in Kathmandu.
2. Foul Odor and Toxic Gas Entering the House
When gases cannot escape, they seep into the house through toilet pans, pipe joints, or small cracks, spreading foul odors. Prolonged exposure to such gases can cause headaches, nausea, eye irritation, and breathing difficulties.
3. Poor Flushing Performance
Without air release through a vent pipe, negative pressure builds inside the tank. This can cause water to drain slowly during flushing or, in some cases, for wastewater to flow back, frequently leading to clogged toilets.
4. Disruption of the Septic Tank’s Biological Process
Bacteria inside the septic tank are responsible for decomposing waste. Excessive gas and pressure can slow down or disrupt this natural process, causing the tank to fill faster and requiring more frequent waste removal. This directly affects both health and expenses.
5. Risk to Sanitation Workers and Technicians
Opening a tank without a vent can release accumulated gas suddenly, potentially causing people to faint or, in severe cases, suffocate. This is one of the major causes of septic tank accidents during cleaning in Nepal.
Every septic tank must have a vent pipe installed. The vent pipe should rise at least 2-3 meters above the tank and, if possible, extend above the building roof. A mesh screen should be installed at the top to prevent insects and rodents from entering.
Although small in appearance, a vent pipe plays a crucial role in safety. Installing a vent pipe is not a luxury; it is an essential infrastructure for safe toilets and safe homes. Ignoring this during construction is akin to inviting risks into your own home.
Therefore, if your home, institution, or school septic tank lacks a vent pipe, consult a technician and have it installed immediately. A small expense can prevent a major accident.
