IS 13414:1992 is the Indian Standard (BIS) for precast concrete septic tanks. This standard specifies the requirements for materials, design, construction, and testing of precast concrete septic tanks. It covers aspects like capacity calculation, minimum dimensions, inlet and outlet arrangements, and workmanship to ensure the structural integrity and functional performance of the tank for primary sewage treatment.
Specifies requirements for precast concrete septic tanks, including design, materials, and construction.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Minimum Concrete Compressive Strength (28-day) | M20 Grade (20 MPa) | 4000 psi (approx. 27.6 MPa) | ASTM C1227-22 |
| Minimum Wall Thickness | 75 mm (for tanks up to 4 kL), 100 mm (for tanks > 4 kL) | Not specified; performance-based structural design required to withstand defined loads. | ASTM C1227-22 |
| Watertightness Test (Leakage) | Drop in water level not to exceed 10 mm in 24 hours. | Loss not to exceed 1 US gallon (3.79 L) in 24 hours for a 1000-gallon tank. | ASTM C1227-22 |
| Compartment Volume Ratio (2-compartment tank) | First compartment to be 2/3 of total capacity. | Primary chamber volume to be not less than 2/3 of total liquid capacity. | AS/NZS 1546.1:2008 |
| Minimum Liquid Depth (below outlet) | 1000 mm | 1000 mm | AS/NZS 1546.1:2008 |
| Minimum Freeboard (Airspace) | 300 mm | Minimum 9 inches (229 mm) or 20% of liquid depth, whichever is greater. | ASTM C1227-22 |
| Access Opening (Manhole) Diameter | Minimum 500 mm clear opening. | Minimum 20 inches (508 mm) in least dimension. | CSA B66-16 |