Sewage is mainly a liquid waste containing some solids, produced by humans. It typically consists of washing water, faeces, urine, laundry waste and other material which goes down drains and toilets from households and industry. Sewage sludge is an end product of the wastewater treatment process. This material can be a wonderful source of nutrients for the soil. This book provides current studies and research on the treatment and use of sewage. Using this material as a fertiliser can benefit the environment by turning wastes into valuable resources. These sludges would otherwise have to be disposed of by landfilling, lagooning, incineration, or ocean dumping. On the other hand, heavy metals sometimes found in sewage sludge may present environmental problems as there is filtration of metals towards the aquifers which get contaminated. This book addresses these concerns as well as benefits.