This document discusses excreta and sewage management. It describes that 15% of rural areas lack access to safe excreta facilities, with 75% using pit latrines and 60% discharging waste directly into the environment. Sewage refers to liquid waste containing excreta, bathing, and kitchen waste water. Improper sewage disposal can spread diseases like typhoid, hepatitis A, and cholera. Common rural sewage disposal methods include pit latrines, while water-based systems in other areas use septic tanks connected to soakaways. Proper sanitary sewage disposal prevents contact of feces with vectors and promotes environmental health.

1. Excreta & Sewage
Management/Disposal
DR A ADENIRAN MBBS, MPH, FMCPH
CONSULTANT PUBLIC HEALTH PHYSICIAN
LAGOS STATE UNIVERSITY (COLLEGE OF MEDICINE)
NIGERIA

2. Learning Objectives
 Describe a sewage and other related terms
 Describe diseases associated with in proper
sewage diaposal
 Describe the different methods of sewage
disposal
 Describe features of a sanitary sewage
disposal

3. Rural
 15% without access to safe excreta disposal
facility
 75% use pit latrines
 60% discharge waste water directly to the
environment
 Poor drainage abound
 No organised way of dealing with solid waste by
most residents
3

4. What is Sewage
 Collective name for liguid or wet refuse
consisting of excreta (faeces & urine), effluent
from bath, kitchen, laundry, rain run off waste
water
 The pipes through which sewage flows are
known as sewers and the network of pipes is
known as sewerage

5.  Excreta contains a variety of pathogens
bacteria, viruses, protozoa, fungi and
helminthes

6. Feacal Borne Diseases Examples
 Typhoid
 Para Typhoid
 Hepatitis A
 Dysenteries
 Diarhoeas
 Cholera
 poliomyelithis
 Helminthic & Parasitic Diseases: e.g Ascariasis,
Trichuriasis, etc

7. Sanitary Latrines
 Prevent the contact of faeces with 5 agents of disease
transmission- water, fingers, flies, soil and food
Features
 No faecal contamination of ground or surface water
 No soil pollution
 No faecal contact with flies and rodents
 Free from odour and unsightly appearance

8. Method of Sewage Disposal
1. Non water carriage system
a. Pit latrine ( common in rural areas, little water, consist of the pit, floor
and superstructure, pit deep as 2.4m, floor should be slab, safe and
strong
There are many modifications of pit latrine aimed at improving the
sanitary features of this method of disposal. Eg VIP (Ventilated
Improved Pit) latrine= minimize flies and odour
b. Bucket latrine (water independent, bad method of sewage disposal,
cheap to start but difficult to operate

11. 2. Water Carriage System
a. Septic Tank & Soak away Pit (ST&SP) Method: Ideal where
there is water, consist of water closet, inspection chamber and
the short pipe (sewer) which leads to the septic tank. The night
soil discharges from the house through the sewer to the septic
tank where it stays and anaerobic action takes place and from
where a clear effluent leaves to the soak away pit and then
absorbed by the surrounding soil. The sludge in the septic tank
is removed when the tank is filled
b. Aqua Privy: Consist of water tight tank, faeces are stored in the
tank which is kept at a constant water level. A soak away is also
provided for the effluent from the aqua privy tank

14. Other Methods
 Chemical Toilet: consist of corrosive resistant container of about
400 – 500 lit of bactericidal liquid e.g strong solution of sodium
hydroxide or formaldehyde
 Composting: Biological destruction process where excreta and
refuse are mixed in a corrosive resistant container. The content is
turned until decomposition is achieved. Humus is produced and
CO2 and other gases are allowed to escape
 Trench Latrine Consist of swallow trenches. Suitable for temporary
sites such as camp, picnic etc, excavated soil from the trenches
are left close to the latrine so that each user can use it to cover
their feaces

16. questions