Get matched with top excavation pros in Captain Cook, HI

There is no standard depth for burying a septic tank; they are typically buried anywhere from 4 inches to 4 feet underground. The final depth depends on several factors, including the depth of your main sewer line, the height of the bedrock, soil type, local regulations, and the property's landscape. If you plan to grow grass or plants over the tank, a depth of at least 4 to 6 inches is recommended. Deeper tanks can be more difficult to locate, but a septic professional can help find it for you.

Sewer lines can be buried anywhere from 18 inches to 8 feet deep, with a common average depth between 18 and 30 inches. The exact depth depends on local factors like climate and soil type. In colder regions, pipes must be buried deeper (below the frost line) to prevent freezing, sometimes as deep as 8 feet. The digging depth can also impact the cost of sewer line replacement. To find the specific depth for your property, you can check the building plans for your system, which should be on file with your city or local sanitation department since permits are required for installation.

Professional installers often include a deep layer of crushed gravel under permeable pavers to allow more runoff to soak through into the soil below. Many installations will include multiple layers of gravel, with coarser aggregate at the base and finer aggregate that sits on top of that bottom layer. Above the gravel, you’ll often find coarse sand that helps reduce paver shifting over time. Some permeable paver designs include a water collection system set into the gravel layer to route runoff to a safe area for disposal.

Generally, a trenchless sewer line is worth the cost. If your old system needs replacement, trenchless sewer repair or replacement can save you thousands on excavation costs. Every homeowner’s situation is different, but this method is definitely worth it in a lot of cases.