Domestic Fertilizers Made From Septage and Sewage?

Fertilizers may be the last things you think of when discussing septage and sewage, but the practice of creating fertilizer from these waste materials has been in use for some time. Treated solids from septage and sewage treatment facilities are sold at a low cost to farmers who insist that these solids provide everything for crops that commercial chemical fertilizers offer.

Why Fertilize?

Soil is naturally rich in many minerals thanks to the plant matter and animal waste that has been absorbed into it over many years. As crops are planted, that soil becomes depleted of nutrients because the crops take more from the soil than nature can readily replenish. When fertilizers are worked into the soil, they release the depleted minerals back into the earth and provide a fertile place in which to grow the next set of crops.

Over the past few decades, interest in non-chemical fertilizers has led to developing ways to fertilize soil without having to rely on chemicals. In this light, septage and sewage solids have been used to make fertilizers.

What Are Septage and Sewage?

Septage is the term used to describe waste from a septic tank. When the tank is pumped out, the waste is taken to a treatment facility and rendered down to small, dark pellets. These pellets are then worked into the soil on a farm to release their mineral rich contents.

When used to fertilize and replenish soil, sewage is not the raw, unfinished by-product that the term usually conjures up. Instead, it is the processed sewage solid that is used on fields. It looks a great deal like mulch, and is applied in the same way—as a cover or worked into the ground.

Why Use Septage and Sewage as Fertilizer?

Using septage and sewage solids as fertilizers resolves more than one problem. The creation of wastes, and the processing of wastes, requires somewhere to put the wastes when processing is complete. Landfills may seem an easy solution, but landfills quickly become overwhelmed by these materials.

Farming depletes minerals from the soil as plants draw them up. Those minerals are eaten by people and animals that eat the crops from the fields. Whatever is not needed is processed through the body and expelled with other wastes. By taking in these materials and returning them to the soil, we complete the cycles that are no longer maintained naturally, ensuring that crops will continue to thrive and provide us with the minerals and nutrients we need.

While not yet widely used for home gardening or in lawn care, septage and sewage solid-based fertilizers are gaining popularity. As with any waste products, there are concerns and risks in the use of these materials. Most of the risks are avoided through careful handling of the raw materials and following proper safety protocols. While concerns about the exact content of fertilizers made from raw waste and their impact on the soil and the environment are understandable, it is important to realize that the vast majority of these items are not things plants would even understand how to absorb. Also, many safeguards are in place to keep processed wastes from having a toxic impact should they be released.