OSTDS: Basic Concepts in Wastewater
Treatment 2025/2026 Exam Questions
and Correct Answers | New Update
One advantage of Onsite Systems - 🧠ANSWER ✔✔It's a source of
groundwater recharge.
Public health and environmental protection officials now acknowledge that
onsite systems are... - 🧠ANSWER ✔✔not just temporary installations, but
permanent approaches.
OSTDS are potentially viable if... - 🧠ANSWER ✔✔planned, designed,
installed, operated, and maintained properly.
Black Water constituents - 🧠ANSWER ✔✔Toilet, Kitchen, Dish Washer.
Gray Water constituents - 🧠ANSWER ✔✔Bath/Shower, Clothes Washer,
Misc
Toilet Generates - 🧠ANSWER ✔✔the most water use per day.
Washing machine generates - 🧠ANSWER ✔✔the most gallons per use.
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
1
, Highest BOD contributor - 🧠ANSWER ✔✔Bathing, sinks, appliances (28.5
gpcd)
Highest TSS contributor - 🧠ANSWER ✔✔Toilet (27.0 gpcd)
Highest Total Nitrogen contributor - 🧠ANSWER ✔✔Toilet (8.7 gpcd)
Highest Total Phosphorus contributor - 🧠ANSWER ✔✔Toilet (1.6 gpcd)
BOD/CBOD5 (Biochemical Oxygen Demand) - 🧠ANSWER ✔✔Amount of
dissolved oxygen organisms need to degrade wastes in wastewater.
TSS (total suspended solids) - 🧠ANSWER ✔✔A portion of wastewater that
has resisted settling, that is retained when passed through a filter.
TN (Total Nitrogen) - 🧠ANSWER ✔✔Ammonia, nitrate, nitrite.
TP (Total Phosphorus) - 🧠ANSWER ✔✔Orthophosphates, polyphosphates,
organic phosphates.
Fecal Coliform - 🧠ANSWER ✔✔Used as indicator organism for the
presence of pathogens and used to determine if wastewater has been
adequately treated.
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
2
Treatment 2025/2026 Exam Questions
and Correct Answers | New Update
One advantage of Onsite Systems - 🧠ANSWER ✔✔It's a source of
groundwater recharge.
Public health and environmental protection officials now acknowledge that
onsite systems are... - 🧠ANSWER ✔✔not just temporary installations, but
permanent approaches.
OSTDS are potentially viable if... - 🧠ANSWER ✔✔planned, designed,
installed, operated, and maintained properly.
Black Water constituents - 🧠ANSWER ✔✔Toilet, Kitchen, Dish Washer.
Gray Water constituents - 🧠ANSWER ✔✔Bath/Shower, Clothes Washer,
Misc
Toilet Generates - 🧠ANSWER ✔✔the most water use per day.
Washing machine generates - 🧠ANSWER ✔✔the most gallons per use.
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
1
, Highest BOD contributor - 🧠ANSWER ✔✔Bathing, sinks, appliances (28.5
gpcd)
Highest TSS contributor - 🧠ANSWER ✔✔Toilet (27.0 gpcd)
Highest Total Nitrogen contributor - 🧠ANSWER ✔✔Toilet (8.7 gpcd)
Highest Total Phosphorus contributor - 🧠ANSWER ✔✔Toilet (1.6 gpcd)
BOD/CBOD5 (Biochemical Oxygen Demand) - 🧠ANSWER ✔✔Amount of
dissolved oxygen organisms need to degrade wastes in wastewater.
TSS (total suspended solids) - 🧠ANSWER ✔✔A portion of wastewater that
has resisted settling, that is retained when passed through a filter.
TN (Total Nitrogen) - 🧠ANSWER ✔✔Ammonia, nitrate, nitrite.
TP (Total Phosphorus) - 🧠ANSWER ✔✔Orthophosphates, polyphosphates,
organic phosphates.
Fecal Coliform - 🧠ANSWER ✔✔Used as indicator organism for the
presence of pathogens and used to determine if wastewater has been
adequately treated.
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER: 619652435. TERMS OF USE. PRIVACY
STATEMENT. ALL RIGHTS RESERVED
2
