Hi Kevin!
A mammoth task that one will be, especially considering the several parameters included in that time that you just mentioned above.
I worked on a faecal sludge characterization and quantification study in Kampala (www.eawag.ch/fileadmin/Domain1/Abteilung...rization_Kampala.pdf) and I recall that the trucks could take anywhere between from 1 to 6 minutes for the actual emptying. Our study was focused on collecting FS samples so we don't have any records of emptying time and this is just my personal estimate. The rest of the items/parameters are (were) quite hard to accurately count since some truck drivers have more complicated valve systems than others and their turn around time also depended on how many trucks were at the discharge point at the moment (and hence more driving manoeuvres to create space for colleagues). And of course their speed at doing things also depended on whether they had another client on call waiting for them or they were going to park in the yard to wait for other clients.

I don't know if this helps in any way but I can appreciate the complexity of estimating that total turn around time!

Good luck!

Regards,
Daniel

Hello all

I am currently working on a book on faecal sludge treatment. One of the key design parameters is the peak flow into a treatment plant. For design purposes, I am following the same convention as used for sewage treatment plants, that the design flow should be the peak flow over a one hour period. One way of estimating this is to assess the number of tankers that can discharge their contents in one hour and this is determined by the time that it takes for a tanker to discharge, including the time taken to get into position, open the discharge valve, discharge its contents and move away so that another tanker can take its place. I would be interested to know whether anyone has field information that might be used to get an estimate of total turn-round time for a particular size of tanker. (There are going to be differences depending on tanker capacity so it would be good to get information for different sizes of tanker, from the 1 -2m3 minimum found in parts of Asia up to the 10m3 or more found in some African towns.

Thanks in advance for any help that anyone can give on this

Kevin