CONTENTS - Central Public Works Department

346 APPENDIX 2
Part II - Materials
21. Requirement of different sizes/types of pipes and specials and method of procurement.
22. Requirement of pig lead
23. Have requirements of pumps and accessories been determined, in consultation with the Electrical
Engineer? Give details.
24. Requirement of any other materials/tools and plants.
PROFORMA – 4 OF APPENDIX 2
SEWERAGE
1. Name of Project
2 (a) Reference to administrative approval and expenditure sanction and their amounts.
(b) Provision for sewerage
(c) Provision for ancillary works such as pumps, sumps, pump houses connection to existing ducts,
septic tanks, etc.
3. (a) Amount of detailed estimate
(b) Rate per sqm as per the detailed estimate and how it compares with provision in administrative
approval.
Part 1 - Engineering Appreciation
4. Area covered (Give details of areas covered, if any, which have not been provided for in A/A: future
extensions, etc.)
5. (a) Population.
(b) Basis of assessment.
(c) Future increase.
6. Sewers
(a) Shape of sewer
(b) Minimum size used
(c) Slopes adopted
(d) Self cleansing velocity assumed and at what depth of flow.
(e) If self-cleansing velocity not possible, have flushing arrangements been made?
(f) Minimum velocity attained in the design
(g) Is designed discharge three times the average discharge
(h) Brief description of the system of sewerage
(i) Design formula and the coefficient of rugosity adopted.
7. Manholes:
(a) Minimum depth of starting manholes.
(b) Types of manholes (rectangular, circular, arch type).
(c) Types of manhole covers used (whether heavy, medium, light) and principles governing their use.
(d) Has location of manhole been fixed on the consideration that:
(i) Each manhole should serve maximum number of plots.
(ii) Manholes provided at bends-change in diameter and gradients.
(e) Maximum distance between two manholes.
(f) Distance of vent shafts; has provision of these been made in the estimates?
(g) Has provision been made for drop connections?
(h) What is the maximum velocity in the sewer? (upto 2.44 metres per second avoids erosion of
invert).
8. Disposal
(a) Arrangement for disposal of sewerage.
(b) Has permission of local body been sought if discharge is led into an existing sewer direct?
(c) Distance of the existing duct from the last manhole in the area.