Wastewater is any water that has been adversely affected in quality by any anthropogenic influence. It therefore includes liquid waste discharged from domestic houses ,industrial, agricultural or commercial processes. It does not include rain-water uncontaminated by man's activities.

There is a wide range of wastewaters and an equally wide range of technologies and techniques for mitigating the impacts of waste-waters on the receiving environment.

Wastewater types

Industrial

• Organic - bio-degradable - includes abbatoirs , creameries, ice-cream manufacture
• Organic - non bio-degradable or difficult to treat - e.g. Pharmaceutical or Pesticide manufacture
• Inorganic - e.g. metal working industry
• extreme pH - acid/alkali manufacture, metal plating
• Toxic - e.g metal plating, cyanide production, pesticide manufature
• Solids and Emulsions - e.g. Papermaking, food stuffs, lubricating and hydraulic oil manufacture
• agricultural drainage - direct and diffuse

surface run-off

• Highway drainage
• Storm drains
• industrial site drainage
• Blackwater - surface water contaminated by sewage

Domestic drainage

• Sewage
• Cesspit leakage
• Septic tank discharge
• Sewage treatment plant discharge
• Greywater also known as Sullage water - water from household functions such as washing dishes, laundry or bath water

Treatment

There are numerous processes that can be used to clean up waste waters depending on the type and extent of contamination. Most wastewater is treated in industrial-scale wastewater treatment plants (WWTPs) which may include physial chemical and biological treament processes. Some wastewater may be highly treated and reused as reclaimed water. For some waste waters ecological approaches using reedbed systems such as constructed wetlands may be appropriate.

See also

• sewers
• sewage treatment
• water industry
• water resources