REHS Exam: Private Onsite Wastewater Treatment
and Disposal fully solved graded A+
1. Biochemical
Oxy- gen The difference between the initial dissolved O2 in a water sample and
Demand (BOD) dissolved O2 in a duplicate sample after a stated period of time (usually 5
days). Best single measure of wastewater or polluted water.
2. Chemical
Oxygen
Demand (COD) A measure of the amount of O2 chemically consumed by the oxidation
of organic and oxidizable inorganic materials in a water sample. Good for
measuring indus- trial wastes.
3. Domesti
c
Sewage used water from a home or community. Includes toilet, bath, laundry,
lavatory, and kitchen-sink wastes. Sewage strength is reported in BOD,
4. National Pollu- SS, and COD
tant Discharge
Elimination
Sys- tem System for issuance of permits for the discharge of treated sanitary,
(NPDES) industrial, and commercial wastes under the 1972 Federal Water
Pollution Control Act. Permit specifies the treatment and expected outcome
of effluent to protect water quality.
5. Privy where excreta is disposed without the aid of water; odor prevention is via 4"
vent extending 18" above roof peak.
6. Point Source
Pol- lution any discernible, confined, or discrete conveyance from which pollutants are
or my be discharged
7. Nonpoint Pollu-
tion not a point source and is manmade/man-induced resulting in the
alteration of the chemical, physical, biological or radiological integrity of
water.
8. How a septic tank purpose: 24-72 hour watertight detention tank, condition sewage to be
more
works Treat- ment Process
9. Sewage
1/
9
, REHS Exam: Private Onsite Wastewater Treatment
and Disposal fully solved graded A+
readily percolated into
the subsoil
functions: removal of
solids, biological
treatment, sludge and
scum storage
Anaerobic digestion:
operates in anoxic
environment, treats
sewage with anaerobic
bacteria, very slow
process (e.g. septic
tank)
Aerobic digestion:
operates in an aerobic
environment, treats
sewage with aerobic
2/
9
and Disposal fully solved graded A+
1. Biochemical
Oxy- gen The difference between the initial dissolved O2 in a water sample and
Demand (BOD) dissolved O2 in a duplicate sample after a stated period of time (usually 5
days). Best single measure of wastewater or polluted water.
2. Chemical
Oxygen
Demand (COD) A measure of the amount of O2 chemically consumed by the oxidation
of organic and oxidizable inorganic materials in a water sample. Good for
measuring indus- trial wastes.
3. Domesti
c
Sewage used water from a home or community. Includes toilet, bath, laundry,
lavatory, and kitchen-sink wastes. Sewage strength is reported in BOD,
4. National Pollu- SS, and COD
tant Discharge
Elimination
Sys- tem System for issuance of permits for the discharge of treated sanitary,
(NPDES) industrial, and commercial wastes under the 1972 Federal Water
Pollution Control Act. Permit specifies the treatment and expected outcome
of effluent to protect water quality.
5. Privy where excreta is disposed without the aid of water; odor prevention is via 4"
vent extending 18" above roof peak.
6. Point Source
Pol- lution any discernible, confined, or discrete conveyance from which pollutants are
or my be discharged
7. Nonpoint Pollu-
tion not a point source and is manmade/man-induced resulting in the
alteration of the chemical, physical, biological or radiological integrity of
water.
8. How a septic tank purpose: 24-72 hour watertight detention tank, condition sewage to be
more
works Treat- ment Process
9. Sewage
1/
9
, REHS Exam: Private Onsite Wastewater Treatment
and Disposal fully solved graded A+
readily percolated into
the subsoil
functions: removal of
solids, biological
treatment, sludge and
scum storage
Anaerobic digestion:
operates in anoxic
environment, treats
sewage with anaerobic
bacteria, very slow
process (e.g. septic
tank)
Aerobic digestion:
operates in an aerobic
environment, treats
sewage with aerobic
2/
9
