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A lined or partially lined underground pit into which raw household wastewater is discharged and from which the liquid seeps into the surrounding soil. Sometimes called a leaching cesspool. (from GLOSSARY: WATER AND WASTEWATER CONTROL ENGINEERING, 1981, prepared by a Joint Committee representing The American Public Health Association, American Society of Civil Engineers, American Water Works Association, and the Water Pollution Control Federation).
Any liquid or solid material removed from a septic tank, cesspool, portable toilet, Type III marine sanitation device, or similar treatment works that receives only domestic sewage. Domestic septage does not include liquid or solid material removed from a septic tank, cesspool, or similar treatment works that receives either commercial wastewater or industrial wastewater and does not include grease removed from a grease trap at a restaurant. (40 CFR 503.9 (f))
Any person who contributes wastewater into the metropolitan sewerage system from a residential dwelling unit. (KCC 28.82.260)
Defined in accordance with 40 CFR 261.3 or amended. (KCC 28.82.330)
Any liquid, solid or gaseous substance, or combination thereof, resulting from any process of industry, government agency, manufacturing, commercial food processing, business, agriculture, trade or research, including, but not limited to, the development, recovery or processing of natural resources, leachate from landfills or other disposal sites, decant water, contaminated nonprocess water, and contaminated stormwater and ground water. (KCC 28.82.380)
(Also referred to as commercial) septage is any liquid or solid material removed from an on-site sewage system that serves businesses, commercial facilities or industries, including restaurants. Businesses and industrial enterprises often discharge wastewater into a septage tank that contains metals or other chemicals not normally found in domestic septage. Common examples of process wastes from commercial activities include: mercury in dental office wastewater (from the amalgam fillings), silver in photo processor wastewater, inks and solvents from printing businesses and pharmaceuticals from veterinary and medical clinics. Industrial users, such as electroplaters, may discharge heavy metals.
A building, either portable or fixed directly directly to a pit or vault, equipped with seating and used to collect human excrement. (from GLOSSARY: WATER AND WASTEWATER CONTROL ENGINEERING, 1981, prepared by a Joint Committee representing The American Public Health Association, American Society of Civil Engineers, American Water Works Association, and the Water Pollution Control Federation).
The liquid and solid material pumped from a septic tank, cesspool, or other primary treatment source. (from EPA 832-F-99-068, September 1999)

For more information about the DNRP Septage Disposal Program, please contact:

Chris Tinnin,
Building and Grounds Coordinator & Septage Supervisor:
 (206) 263-1821
 chris.tinnin@kingcounty.gov