---
title: "Importance and objectives of wastewater disposal"
subject: "Sanitary Engineering"
chapter: 6
key: "semester_6/sanitary_engineering:objectives-wastewater-disposal"
source: https://www.bctengineer.com/q/semester_6/sanitary_engineering/objectives-wastewater-disposal
site: BCT Engineering
---

# Importance and objectives of wastewater disposal

Sanitary Engineering · Chapter 6: Wastewater Disposal

- Asked in: 2073 Bhadra, 1+3 marks; 2070 Magh, 4 marks; 2068 Bhadra (old course), 6 marks (asked 3 times)
- Video: [Introduction to Wastewater Engineering - Wastewater Engineering for GATE CE/ ESE/PSU Exams](https://www.youtube.com/watch?v=k9yOQTyXn4o) — Lead GATE -  ME,XE,PI
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/sanitary_engineering/objectives-wastewater-disposal
- Whole chapter: https://www.bctengineer.com/md/semester_6/sanitary_engineering/chapter-6

## Question

Why is scientific management / wastewater management necessary (important) for the community? State/enlist the objectives of sewage (wastewater) disposal.

## Short answer

Wastewater management prevents disease, water pollution, and nuisance. Objectives: protect public health, prevent pollution of water sources, protect aquatic life, avoid odour/flies, meet legal standards, recover resources (water, biogas), and dispose safely at least cost.

## Answer

#### Necessity (importance) of wastewater management
Wastewater produced by a community contains pathogens, organic matter, nutrients and toxic substances. If it is left on the street or let into rivers without treatment, it:
- spreads waterborne diseases (cholera, typhoid, dysentery, hepatitis, diarrhoea),
- pollutes surface water and groundwater that people use for drinking, bathing and irrigation,
- kills fish and aquatic life by depleting oxygen, and causes eutrophication,
- gives bad smell, mosquitoes and flies, and spoils the look of the city,
- blocks the drains and causes flooding, and
- reduces land value and tourism.

So scientific management (collection, treatment and safe disposal) is necessary for public health, protection of the environment and economic development, and is required by law (Environment Protection Act 2076 and Environment Protection Rules 2077, which replaced the Act 2053 and Rules 2054).

#### Objectives of sewage (wastewater) disposal
1. To **protect public health** by preventing contact of people with pathogens and by controlling disease carriers.
2. To **prevent pollution of water sources**: streams, lakes and groundwater, so that the quality of the water supply remains safe.
3. To **protect aquatic life** and the ecological balance of the receiving water (by maintaining dissolved oxygen).
4. To **avoid nuisance**: bad smell, flies, mosquitoes, and unsightly conditions.
5. To **meet the legal standards** for effluent (Nepal's generic standards).
6. To **recover resources**: reuse of treated water for irrigation and industry, biogas from sludge, and sludge as manure.
7. To **protect the soil and crops** from clogging and contamination.
8. To dispose of the wastewater in the **cheapest and safest way**, with the least treatment that meets the above aims.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Why is wastewater management necessary?
   A. Untreated wastewater spreads waterborne diseases and pollutes water sources
   B. Wastewater is harmless
   C. It increases dissolved oxygen
   D. It raises land value
   Answer: A. Pathogens and organic matter cause disease and pollution. (Key point: Necessity)

2. What effect does untreated sewage have on rivers?
   A. Raises oxygen
   B. Depletes oxygen, kills fish and causes eutrophication
   C. Purifies the water
   D. Reduces nutrients
   Answer: B. Oxygen is consumed by decomposition. (Key point: Environmental effect)

3. Which is an objective of sewage disposal?
   A. Increase mosquitoes
   B. Maximise treatment cost
   C. Protect public health and prevent pollution of water sources
   D. Pollute groundwater
   Answer: C. Also avoid nuisance and meet effluent standards. (Key point: Objective)

4. Which resource recovery is mentioned?
   A. Drinking water only
   B. Raw sewage sale
   C. Nothing
   D. Treated water for irrigation, biogas, sludge as manure
   Answer: D. Resource recovery is an objective. (Key point: Resource recovery)

## Related in Sanitary Engineering

- [Is treatment necessary? Town wastewater 300 l/s](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Atreatment-needed-town-300-ls) — Sanitary Engineering, chapter 6
- [Methods of sewage disposal](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Amethods-sewage-disposal) — Sanitary Engineering, chapter 6
- [Wastewater examination and sampling](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Awastewater-sampling) — Sanitary Engineering, chapter 5, asked 2×
- [Why examine wastewater; solids procedure](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Aexamination-necessity-solids-procedure) — Sanitary Engineering, chapter 5
- [Degree of treatment, industrial wastewater](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Adegree-treatment-industrial-waste) — Sanitary Engineering, chapter 6
- [Importance and methods of waste management](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Aimportance-waste-management-methods) — Sanitary Engineering, chapter 1, asked 7×

## Related in other subjects

- [Organization vs management; scientific approach](https://www.bctengineer.com/question.md?key=semester_7%2Forganization_and_management%3Aorg-vs-management-scientific) — Organization and Management, chapter 2
- [Scientific management and Taylor's principles](https://www.bctengineer.com/question.md?key=semester_7%2Forganization_and_management%3Ascientific-management-taylor) — Organization and Management, chapter 3
- [Behavioral vs scientific management theory](https://www.bctengineer.com/question.md?key=semester_7%2Forganization_and_management%3Abehavioral-vs-scientific) — Organization and Management, chapter 3
- [Short note: Scientific theory of management](https://www.bctengineer.com/question.md?key=semester_8%2Fconstruction_management%3Ascientific-management-note) — Construction Management, chapter 10