IS 2470:2007 Part 1 is the Indian Standard (BIS) for installation of septic tanks, part 1: design criteria and construction (fourth revision). Code of practice outlining the design criteria, sizing, and construction details for septic tanks used in domestic wastewater primary treatment. It specifies dimensions, capacities based on user load, and structural practices to ensure watertight and efficient anaerobic digestion.
Provides guidelines for the design criteria and construction practices for domestic septic tanks.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Minimum Liquid Capacity | 1000 litres (for up to 5 users) | Varies by jurisdiction; 1,000 gallons (approx. 3785 litres) for a 3-bedroom house is common | EPA 625/R-00/008 (2002) |
| Minimum Liquid Depth | 1.0 m | 0.9 m (3 ft) | AS/NZS 1546.1:2008 |
| Minimum Freeboard | 300 mm | 225 mm | AS/NZS 1546.1:2008 |
| Recommended Desludging Interval | Not less than 2 years | Generally 3 to 5 years, based on usage and tank size | EPA 625/R-00/008 (2002) |
| Sludge Accumulation Rate (Typical Design) | 30 litres/person/year | 0.05 m³/person/year (50 litres/person/year) | EPA 625/R-00/008 (2002) |
| Compartment Ratio (First Chamber) | Two-thirds of total length | One-half to two-thirds of total liquid volume | EPA 625/R-00/008 (2002) |
| Inlet/Outlet Invert Level Difference | Inlet invert minimum 75 mm above outlet invert | Inlet invert typically 50-75 mm (2-3 inches) above outlet invert | EPA 625/R-00/008 (2002) |