Environmental sanitation planning and infrastructures in developing countries

Environmental sanitation planning and infrastructures in developing countries Faecal Sludge Collection and transport technologies Doulaye Koné SANDEC / EAWAG – Switzerland www. sandec. ch kone@eawag. ch Tel. +41 44 823 55 53 1

On-site sanitation = the hidden reality 1. 70 -100 % of cities and towns in developing countries served by on-site sanitation (latrines and septic tanks) 2. All installations produce FS to be collected ( trucks replacing sewer lines ? ) 3. Lack of regulations, illegal dumping and use of FS untreated 2

Challenges: how to shift our mind set? Engineers’ thrusts and beliefs How to empty this pit ? What happens next ?

The challenge Problems Pit emptying and FS haulage ¨ Traffic congestion ¨ No access to pits 4

The challenge • Distance? • Reuse potential? • Humidity (hygienic quality)? • Additional treatment (storage)? • Greywater collection transportation and treatment? • Quantity (size of neighbourhood)? • Business opportunity?

Latrines emptying technology How does latrines technologies influence emptying technologies and performances ?

DRY PIT LATRINE

POUR FLUSH LATRINE

SUCKING FROM TOP LEAVES DENSE SLUDGE

WATER ADDED FROM TOP DOES NOT MIX

HAND STIRRING IS NOT EFFECTIVE

SUCKING FROM BOTTOM REMOVES SLUDGE FIRST

INJECTED WATER MIXES WITH SLUDGE

WATERTIGHT PIT BOTTOM MAKES SUCKING EASIER

Urine diverted latrine

Faecal sludge viscosity 1 - w Lo 2 ow : L + 3 M ed : m ed + 4 Hi gh - : H ig 1. low- viscosity zone 2. low- : low+ viscosity zone h+ 3. med : med+ viscosity zone 4. high- : high+ viscosity zone

Manual emptying where trucks cannot access/pump or households cannot pay the service Manual emptying (70%) Dupimg in the street, Reuse in agriculture In the street Photo: P. Blunier, 2004

Manual emptying where trucks cannot access/pump or households cannot pay the service

Transportation of manually-emptied solids and liquids

Animal-cart transportation Locally manufactured emptying technology Collection of dried sludge

Vacutug Specifications • WEIGHT: 950 KG. • SIZE : L 3900 mm X W 1350 -mm X H 2000 mm • SPEED: 5 Km/hr • ENGINE: Four stroke 8 HP HONDA models GX 240 petrol engine with Electronic ignition. • VACUUM PUMP • TANK : 500 liters capacity • CAPITAL COST of MARK II: USD$ 5, 100 (excluding freight)

UN-Habitat Vacutug

• A Vietnamese model e. g. Haiphong: Tanks in narrow lanes accessible by small vehicles 24

TRACTOR TRAILED VACUUM TANKER

MICRAVAC

Imported cesspits trucks • • Expensive maintenance Spare parts often lacking Out of age Not appropriate

Locally manufactured cesspits trucks • Low-cost operation and maintenance • Maintenance skills and spare parts available

Locally manufactured cesspits trucks