ossf & tceq UPDATED ACTUAL Exam
Questions and CORRECT Answers
aerobic digestion - CORRECT ANSWER - bacterial decomposition and stabilization of
sewage in presence of free oxygen
aerobic unit treatment size - CORRECT ANSWER - most residential aerobic systems can
treat 500 gallons/day
the 4 parts of an aerobic treatment unit - CORRECT ANSWER - 1. pretreatment tank
2. aeration chamber
3. settling chamber
4. final treatment and dispersal component
what is the most common wastewater treatment system in texas? - CORRECT ANSWER -
aerobic treatment unit
what is a clarifier - CORRECT ANSWER - it allows the cell mass and nondegradable
materials to settle from the water before it goes to treatment
aerobic treatment unit - CORRECT ANSWER - greatly lowers the BOD and reduces the
suspended solids that do not settle at the bottom of the clarifier.
alter system - CORRECT ANSWER - ILLEGAL WITHOUT PERMIT
includes: increasing volume of flow, change in type of waste, change in construction or design
anaerobic digestion - CORRECT ANSWER - bacterial decomposition and stabilization of
sewage in the absence of oxygen
,most common method of anerobic digestion - CORRECT ANSWER - septic tank
borehole - CORRECT ANSWER - a drilled hole 4 feet or greater in depth and 1-3 feet in
diameter
cesspool - CORRECT ANSWER - non-watertight , covered receptacle intended for he receipt
and partial treatment of sewage. Has open-jointed sidewalls and bottom to allow gradual
discharge of affluent while retaining solids for anaerobic decomposition
cluster system - CORRECT ANSWER - sewage collection/treatment/disposal system
designed for 2+ units on separate legal tracts of land where total flow is less than 5000
gallons/day
what type of ossf system is not authorized under 285 - CORRECT ANSWER - cluster system.
Old ones can be kept and maintained, but no new ones can be built
Condensate Drain - CORRECT ANSWER - pipe used for disposal of water generated by AC
units, fridges, etc. Creates extra volume requirement if attached to OSSF
Edwards aquifer recharge zone - CORRECT ANSWER - area where stratigraphic units
constituting edwards aquifer crop out and creates potential for recharge of surface waters into the
aquifer.
how large does a tract of land on the edwards aquifer recharge zone need to be - CORRECT
ANSWER - 1 acre
how big is an acre - CORRECT ANSWER - 43,560 square feet
how far does a sewage treatment tank or holding tank need to be from the aquifer recharge zone -
CORRECT ANSWER - 50 feet
, how far does a soil absorption zone need to be from the aquifer recharge zone - CORRECT
ANSWER - 100 feet
floodplain - CORRECT ANSWER - any area susceptible to a flood from any source and
subject to the statistical 100-year flood
geotextile filter fabric - CORRECT ANSWER - non-woven fabric suitable for wastewater
applications
Gravel-less drain field pipe - CORRECT ANSWER - distributes wastewater into soil like
conventional systems, but it's surrounded by geotextile fabric instead of gravel. can only be used
where subsurface disposal is suitable
pipe trenches - CORRECT ANSWER - seen on gravel-less pipe. where that pipe is placed. 2
feet wide and less than 150 feet long. trenches are connected with 4 inch diameter pipe
what is a Gravel-less drain field pipe made of - CORRECT ANSWER - high density
polyethylene and enclosed in a layer of unwoven spun-bonded polypropylene, polyester or nylon
filter wrap
Grease Interceptor - CORRECT ANSWER - flotation chambers where grease floats to the
water surface and is retained while the clearer water underneath is discharged. must be cleaned
out regularly
where is a grease interceptor used - CORRECT ANSWER - kitchen waste-lines from
institutions, hotels, restaurants, schools, lunchrooms
Groundwater - CORRECT ANSWER - subsurface water occurring in soils and geologic
formations that are fully saturated year-round or seasonally
holding tank - CORRECT ANSWER - watertight container equipped with a high-level alarm
used to receive and store sewage pending its delivery to an approved treatment process
Questions and CORRECT Answers
aerobic digestion - CORRECT ANSWER - bacterial decomposition and stabilization of
sewage in presence of free oxygen
aerobic unit treatment size - CORRECT ANSWER - most residential aerobic systems can
treat 500 gallons/day
the 4 parts of an aerobic treatment unit - CORRECT ANSWER - 1. pretreatment tank
2. aeration chamber
3. settling chamber
4. final treatment and dispersal component
what is the most common wastewater treatment system in texas? - CORRECT ANSWER -
aerobic treatment unit
what is a clarifier - CORRECT ANSWER - it allows the cell mass and nondegradable
materials to settle from the water before it goes to treatment
aerobic treatment unit - CORRECT ANSWER - greatly lowers the BOD and reduces the
suspended solids that do not settle at the bottom of the clarifier.
alter system - CORRECT ANSWER - ILLEGAL WITHOUT PERMIT
includes: increasing volume of flow, change in type of waste, change in construction or design
anaerobic digestion - CORRECT ANSWER - bacterial decomposition and stabilization of
sewage in the absence of oxygen
,most common method of anerobic digestion - CORRECT ANSWER - septic tank
borehole - CORRECT ANSWER - a drilled hole 4 feet or greater in depth and 1-3 feet in
diameter
cesspool - CORRECT ANSWER - non-watertight , covered receptacle intended for he receipt
and partial treatment of sewage. Has open-jointed sidewalls and bottom to allow gradual
discharge of affluent while retaining solids for anaerobic decomposition
cluster system - CORRECT ANSWER - sewage collection/treatment/disposal system
designed for 2+ units on separate legal tracts of land where total flow is less than 5000
gallons/day
what type of ossf system is not authorized under 285 - CORRECT ANSWER - cluster system.
Old ones can be kept and maintained, but no new ones can be built
Condensate Drain - CORRECT ANSWER - pipe used for disposal of water generated by AC
units, fridges, etc. Creates extra volume requirement if attached to OSSF
Edwards aquifer recharge zone - CORRECT ANSWER - area where stratigraphic units
constituting edwards aquifer crop out and creates potential for recharge of surface waters into the
aquifer.
how large does a tract of land on the edwards aquifer recharge zone need to be - CORRECT
ANSWER - 1 acre
how big is an acre - CORRECT ANSWER - 43,560 square feet
how far does a sewage treatment tank or holding tank need to be from the aquifer recharge zone -
CORRECT ANSWER - 50 feet
, how far does a soil absorption zone need to be from the aquifer recharge zone - CORRECT
ANSWER - 100 feet
floodplain - CORRECT ANSWER - any area susceptible to a flood from any source and
subject to the statistical 100-year flood
geotextile filter fabric - CORRECT ANSWER - non-woven fabric suitable for wastewater
applications
Gravel-less drain field pipe - CORRECT ANSWER - distributes wastewater into soil like
conventional systems, but it's surrounded by geotextile fabric instead of gravel. can only be used
where subsurface disposal is suitable
pipe trenches - CORRECT ANSWER - seen on gravel-less pipe. where that pipe is placed. 2
feet wide and less than 150 feet long. trenches are connected with 4 inch diameter pipe
what is a Gravel-less drain field pipe made of - CORRECT ANSWER - high density
polyethylene and enclosed in a layer of unwoven spun-bonded polypropylene, polyester or nylon
filter wrap
Grease Interceptor - CORRECT ANSWER - flotation chambers where grease floats to the
water surface and is retained while the clearer water underneath is discharged. must be cleaned
out regularly
where is a grease interceptor used - CORRECT ANSWER - kitchen waste-lines from
institutions, hotels, restaurants, schools, lunchrooms
Groundwater - CORRECT ANSWER - subsurface water occurring in soils and geologic
formations that are fully saturated year-round or seasonally
holding tank - CORRECT ANSWER - watertight container equipped with a high-level alarm
used to receive and store sewage pending its delivery to an approved treatment process
