Septic Installer Test For Washington State (WOSSA) EXAM Questions and
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1. ANSI American National Standards Institute
2. BOD biochemical oxygen demand, typically expressed in mg/L.
3. CBOD Carbonaceous Biochemical Oxygen Demand, expressed in mg/L.
4. FC Fecal Coliform, expressed in number of colonies 100/ml.
5. LOSS large on-site sewage system
6. NSF Nation Sanitation Foundation International
7. O&G Oils and Grease, component of sewage typically originating from food stuffs
(animal fats of vegetable oils) expressed in mg/L.
8. RS&G Recommended Standards and Guidance
9. SSAS a subsurface soil absorption system
10. TAC Technical Advisory Committee established in WAC 247-272A-0400
11. TN Total Nitrogen, expressed in mg/L.
12. TSS Total Suspended Solids. A measure of the total suspended solids in a given
solution, expressed in mg/L.
13. USEPA United States Environmental Protection Agency
14. Additive a commercial product added to an on-site sewage system intended to affect the
performance or aesthetics of an on-site sewage system
15. Approved Acceptable to the authority having jurisdiction. Local health officer or the depart-
ment
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16. BED a soil dispersal component consisting of an excavation with a width greater than
3 feet
17. Building Sewer that part of the horizontal piping of a drainage system which starts from the end
of the building drain and which receives the discharge of the building drain and
conveys it to a public sewer, private sewer, individual sewage disposal system or
other point of disposal. It begins two feet outside the building wall and conveys
sewage from the building drain to the remaining portions of the on-site sewage
system.
18. Cesspool a covered hole or pit for receiving drainage or sewage, as from a house allowing
liquid to seep into the surronding rock or soil
19. Conforming Sys- an on-site sewage system of component meeting rules of: New construction
tem requirements
Approved and installed within previous requirements
Permitted by WAC-246-272A-0420
20. Cover Material Soil placed over dispersal component, made up of mineral material with no
greater than 10% organic content. Cover may contain organic surface material,
an organic landscaper to help reduce and contain soil erosion.
21. Cuts and Banks a naturally occurring or artificially formed slope greater than one hundred percent
(forty-five degrees) and extending vertically at least five from the toe of the slope
to top of the slope.
22. Department Washington State Department of Health
23. Designer Person who matches site and soil characteristics with approved components
24. Design Flow Means the maximum volume of sewage a residence, structure or other facility
is estimated to generate in a twenty-four hour period. It incorporates both an
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operating capacity and a surge capacity for the system during periodic heavy use
events. The sizing and design of a on-site sewage system component is based on
the design flow.
25. Development The creation of a residence, structure, facility, subdivision, area, or similar activity
resulting in the production of sewage.
26. Disinfection The process of destroying pathogens in sewage through the application of chlo-
rination, ultra-violent light, or ozonation.
27. Distribution any arrangement of equipment and/or material that distributes sewage within
Technology and on-site sewage system.
28. Drainfield subsurface soil absorption system, and soil dispersal component
29. Drainrock cleaned washed gravel or crushed rock ranging in size from 3/4" to 2.5", and
containing no more than two percent by weight passing a US No.8 sieve and no
more than one percent by weight passing through a US No. 200 Sieve.
30. Effluent liquid waste discharged to a septic tank or other on-site sewage system
31. Expanding Clay means a clay soil with the mineralogy of clay particles. Clay particles expand when
absorbing water
32. expansion a change in residence, facility or site that results in the quantity of sewage to
exceed the original design
33. Extremely grave- soils with 60% or more, but not less than 90% rock fragments by volume.
ly
34. Failure
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a condition of an on-site sewage component that threatens the public health by
inadequately treating the sewage, or creating a potential direct or indirect contact
between sewage and the public.
35. Fecal coliform bacteria found in the intestinal tracts of warm-blooded animals that are cultured
bacteria in standard tests. Generally expressed as colonies per 100 ml.
36. Gravely Soils with 15% or more, but less than 35% rock fragments by volume.
37. Gray Water Sewage from bathtubs, showers, bathroom sinks, kitchen sinks, washing ma-
chines, and dishwashers.
38. Ground water Subsurface water in the zone of saturated soils, seasonally, permanently, or as the
result of the tides.
39. Holding tank an on-site sewage system that a holding tank with no discharge outlet
sewage system
40. hydraulic loading the amount of effluent applied to a given treatment step, expressed as gallons per
rate square foot per day, (gal./sq.ft./day)
41. industrial waste Waste from production of consumer goods, mining, agriculture and petroleum
extraction and refining
42. Infiltrative sur- Surface within a treatment component or soil dispersal component to which
face effluent is applied and through which effluent moves into original, undisturbed
soil or other porous treatment media.
43. Installer a person approved by the local health office to install on-site sewage systems or
components
44. The provincial or municipal health officer.
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1. ANSI American National Standards Institute
2. BOD biochemical oxygen demand, typically expressed in mg/L.
3. CBOD Carbonaceous Biochemical Oxygen Demand, expressed in mg/L.
4. FC Fecal Coliform, expressed in number of colonies 100/ml.
5. LOSS large on-site sewage system
6. NSF Nation Sanitation Foundation International
7. O&G Oils and Grease, component of sewage typically originating from food stuffs
(animal fats of vegetable oils) expressed in mg/L.
8. RS&G Recommended Standards and Guidance
9. SSAS a subsurface soil absorption system
10. TAC Technical Advisory Committee established in WAC 247-272A-0400
11. TN Total Nitrogen, expressed in mg/L.
12. TSS Total Suspended Solids. A measure of the total suspended solids in a given
solution, expressed in mg/L.
13. USEPA United States Environmental Protection Agency
14. Additive a commercial product added to an on-site sewage system intended to affect the
performance or aesthetics of an on-site sewage system
15. Approved Acceptable to the authority having jurisdiction. Local health officer or the depart-
ment
, Septic Installer Test For Washington State (WOSSA) EXAM Questions and
Answers (Verified Answers) Study Guide (latest version verified for accuracy
| 2026 Latest!!
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16. BED a soil dispersal component consisting of an excavation with a width greater than
3 feet
17. Building Sewer that part of the horizontal piping of a drainage system which starts from the end
of the building drain and which receives the discharge of the building drain and
conveys it to a public sewer, private sewer, individual sewage disposal system or
other point of disposal. It begins two feet outside the building wall and conveys
sewage from the building drain to the remaining portions of the on-site sewage
system.
18. Cesspool a covered hole or pit for receiving drainage or sewage, as from a house allowing
liquid to seep into the surronding rock or soil
19. Conforming Sys- an on-site sewage system of component meeting rules of: New construction
tem requirements
Approved and installed within previous requirements
Permitted by WAC-246-272A-0420
20. Cover Material Soil placed over dispersal component, made up of mineral material with no
greater than 10% organic content. Cover may contain organic surface material,
an organic landscaper to help reduce and contain soil erosion.
21. Cuts and Banks a naturally occurring or artificially formed slope greater than one hundred percent
(forty-five degrees) and extending vertically at least five from the toe of the slope
to top of the slope.
22. Department Washington State Department of Health
23. Designer Person who matches site and soil characteristics with approved components
24. Design Flow Means the maximum volume of sewage a residence, structure or other facility
is estimated to generate in a twenty-four hour period. It incorporates both an
, Septic Installer Test For Washington State (WOSSA) EXAM Questions and
Answers (Verified Answers) Study Guide (latest version verified for accuracy
| 2026 Latest!!
Study online at https://quizlet.com/_jq4p96
operating capacity and a surge capacity for the system during periodic heavy use
events. The sizing and design of a on-site sewage system component is based on
the design flow.
25. Development The creation of a residence, structure, facility, subdivision, area, or similar activity
resulting in the production of sewage.
26. Disinfection The process of destroying pathogens in sewage through the application of chlo-
rination, ultra-violent light, or ozonation.
27. Distribution any arrangement of equipment and/or material that distributes sewage within
Technology and on-site sewage system.
28. Drainfield subsurface soil absorption system, and soil dispersal component
29. Drainrock cleaned washed gravel or crushed rock ranging in size from 3/4" to 2.5", and
containing no more than two percent by weight passing a US No.8 sieve and no
more than one percent by weight passing through a US No. 200 Sieve.
30. Effluent liquid waste discharged to a septic tank or other on-site sewage system
31. Expanding Clay means a clay soil with the mineralogy of clay particles. Clay particles expand when
absorbing water
32. expansion a change in residence, facility or site that results in the quantity of sewage to
exceed the original design
33. Extremely grave- soils with 60% or more, but not less than 90% rock fragments by volume.
ly
34. Failure
, Septic Installer Test For Washington State (WOSSA) EXAM Questions and
Answers (Verified Answers) Study Guide (latest version verified for accuracy
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Study online at https://quizlet.com/_jq4p96
a condition of an on-site sewage component that threatens the public health by
inadequately treating the sewage, or creating a potential direct or indirect contact
between sewage and the public.
35. Fecal coliform bacteria found in the intestinal tracts of warm-blooded animals that are cultured
bacteria in standard tests. Generally expressed as colonies per 100 ml.
36. Gravely Soils with 15% or more, but less than 35% rock fragments by volume.
37. Gray Water Sewage from bathtubs, showers, bathroom sinks, kitchen sinks, washing ma-
chines, and dishwashers.
38. Ground water Subsurface water in the zone of saturated soils, seasonally, permanently, or as the
result of the tides.
39. Holding tank an on-site sewage system that a holding tank with no discharge outlet
sewage system
40. hydraulic loading the amount of effluent applied to a given treatment step, expressed as gallons per
rate square foot per day, (gal./sq.ft./day)
41. industrial waste Waste from production of consumer goods, mining, agriculture and petroleum
extraction and refining
42. Infiltrative sur- Surface within a treatment component or soil dispersal component to which
face effluent is applied and through which effluent moves into original, undisturbed
soil or other porous treatment media.
43. Installer a person approved by the local health office to install on-site sewage systems or
components
44. The provincial or municipal health officer.
