📌 Introduction
The design of septic tank size in India is governed by IS 2470 (Part 1 & Part 2) standards. Proper sizing and layout of septic tanks and soak pits are essential for safe wastewater disposal in residential and commercial buildings.
This article provides:
✔ Septic tank CAD file download
✔ Soak pit DWG drawing
✔ Septic tank size calculator
✔ Design based on IS 2470
✔ Rectangular & circular tank sizing
📏 Septic Tank Design as per IS 2470
📌 Key IS Code Requirements:
✔ Minimum detention time: 24–48 hours
✔ Minimum liquid depth: 1.0 to 1.5 m
✔ Freeboard: 300 mm
✔ Length : Width ratio = 2:1 to 4:1
✔ Minimum width: 750 mm
✔ Provide baffle wall
Septic Tank and Soak Pit CAD File Download (DWG) 175.33 KB 3 downloads
🚰 Septic Tank Size Calculator Number of Users: Water Usage (Litres per person): Retention...🧮 Septic Tank Size Calculation Formula (IS 2470)
📌 Basic Formula:
Volume (Litres) = Number of Users × 135 LPCD × Detention Time (Days)
👉 Convert to m³:
Volume (m³) = Litres / 1000
🧮 Septic Tank Size Calculator (IS Standard)
🚰 Septic Tank Calculator (IS 2470)
📊 Septic Tank Size Chart (IS Based)
| Users | Volume (m³) |
|---|---|
| 5 | 1.35–2.0 |
| 10 | 2.7–4.0 |
| 20 | 5.4–8.0 |
🕳️ Soak Pit Design as per IS
📌 Guidelines:
✔ Diameter: 1 to 2.5 m
✔ Depth: 2 to 3 m
✔ Filled with brick ballast / stones
✔ Located away from water sources
✔ Provide perforated lining
⚠️ Important IS Code Safety Points
- Distance from well: Minimum 15–30 m
- Provide vent pipe
- Ensure watertight construction
- Avoid contamination of groundwater
FAQ
What is septic tank size as per IS code?
It depends on users, typically based on 135 LPCD and 24–48 hours detention.
What is detention time in septic tank?
It is the time wastewater stays in tank, usually 1–2 days.
Which IS code is used for septic tank?
IS 2470 Part 1 & 2.
What is soak pit size as per IS?
1–2.5 m diameter and 2–3 m depth.
