In many larger wastewater treatment systems, per-treatment regulation requires that industrial facilities pretreat their wastewater to remove many hazardous containments before wastewater can be sent to the treatment plant.
The sewage then goes through physical, chemical and biological process to clean the wastewater and remove the solids, which will in turn become biosolids. After treatment and processing, biosoilds are recycled and used as fertilizers to help improve and simulate plant life by improving soil tilt, enhancing moisture retention and helping to combat soil erosion. The benefits are also extended to costs as well. Sewage sludge is heavy due to its water content and there for costly to move. On the other hand, biosolids still contain water, but can be sold as fertilizer and can pass the cost of freight onto the buyer. This conservation helps to protect surface and ground waters as well from contamination from sewage waste