Updated October 2026. Dimensions from manufacturer spec sheets (Oldcastle, Jensen Precast, Norwesco); models vary, so check the exact tank.
A 1,000 gallon septic tank is usually about 8 feet long, 4 to 5.5 feet wide and 5 to 6 feet tall if it is concrete. Plastic 1,000 gallon tanks are longer and lower: Norwesco’s model is about 10.5 feet long, 5 feet wide and just over 4 feet tall. Exact sizes depend on the maker, the material and whether the tank is built for vehicle traffic.
1,000 gallon septic tank dimensions by model
| Tank | Length | Width | Height | Weight |
|---|---|---|---|---|
| Oldcastle precast concrete, non-traffic | 8 ft | 4 ft 4 in | 5 ft | 9,130 lb |
| Jensen Precast concrete, traffic rated (HS20-44) | 98 in (8 ft 2 in) | 64 in (5 ft 4 in) | 72 in (6 ft) | 13,619 lb |
| Norwesco plastic, single compartment (42405) | 127 in (10 ft 7 in) | 60 in (5 ft) | 51 in (4 ft 3 in) | About 357 lb |
Figures from each maker or distributor spec page, checked October 2026.
The hole is bigger than the tank. Installers dig extra room on each side for bedding and backfill, so plan the excavation with your installer and permit drawing.
Concrete vs plastic 1,000 gallon tanks
Concrete tanks weigh tons, need a boom truck to set, and resist floating in a high water table. Plastic tanks weigh a few hundred pounds, can be set with light equipment, but must be anchored in wet ground and cannot sit under driveways. See concrete vs plastic septic tanks for costs and lifespan.
How many bedrooms can a 1,000 gallon tank serve?
Usually up to 3 bedrooms, and up to 4 in some states. Washington allows 1,000 gallons for up to 4 bedrooms, while Minnesota requires 1,500 gallons for 4. Use our septic tank size calculator or see how many bedrooms a 1,000 gallon tank supports.
Replacing or installing a 1,000 gallon tank?
Size, site access and permit rules all affect which tank fits. Talk to a local septic company about options and a quote.
Calls are answered by a pay-per-call partner network that connects you with a local septic company. Calling is free; we may be paid for referrals.
How deep is a 1,000 gallon septic tank buried?
Burial depth depends on how deep the house sewer line leaves the foundation and on the site. Each tank model has its own limits: Jensen lists its traffic-rated 1,000 gallon tank for 1.1 to 6 feet of cover. If the lids are deep, a septic tank riser brings them up to the surface.
Pumping a 1,000 gallon septic tank
The EPA says most household tanks should be pumped every 3 to 5 years, with the interval depending on tank size and how many people live in the home. A large household on a 1,000 gallon tank may need pumping toward the shorter end of that range. See how often to pump a septic tank and what pumping costs.
Quick answers
How much does a 1,000 gallon septic tank weigh?
About 9,000 to 14,000 pounds for the concrete tanks above, depending on the design, and a few hundred pounds for plastic.
What are the dimensions of a 1,500 gallon septic tank?
See 1,500 gallon septic tank dimensions.
How do I find the size of my existing tank?
Check the permit or as-built drawing, an old pumping receipt, or ask the pumper. See how to find your septic tank records.
Is a 1,000 gallon septic tank big enough?
For most homes up to 3 bedrooms, yes. Larger households or a garbage disposal may call for 1,250 to 1,500 gallons. See our 1,000 gallon septic tank buyers guide.
Sources
- Oldcastle Infrastructure, 1,000 gallon septic tank, non-traffic rated
- Jensen Precast, Traffic rated septic tank, 1,000 gallon
- Barr Plastics, Norwesco 1,000 gallon one compartment septic tank (42405)
- U.S. EPA, How to care for your septic system