We are currently emptying pit latrines in Kigali Rwanda with moderate success using an eVac and Gulper. We had a vision for transfer stations across the city but some of the areas are so steep that the effective areas for the transfer stations are truly minimal...as a result we're having to park a truck roadside and carry sludge in 25kg lots to the truck. Thats 100 barrels for the average 2.5 tonnes we remove. Average distance to the road of about 300/400m but a vertical drop or climb of 100/200m. Very steep - not a great job, lots of laborers necessary.
Any got a better idea? I imagine the only alternative is a long pipeline but I don't know the limits of pumps well. I imagine boosting from the pit side is easier, but bear in mind access to pit is so poor - whatever we bring there, we need to be able to carry. Can we suck from the truck end? What are the typical 'sucking' limits on tankers and how might I enhance that?
We're prepared to absorb the capital costs, so we can afford to spend some money, but we would like operational costs to remain at a level the customer can afford (~$50)