Hello Elizabeth and the team,

I actually did not find any information regarding the matter from the existing publications!. However, after a close interview and observation from the existing HHs with unroofed pit latrines here in Dar es Salaam, my observation was that unroofing might contribute very little in accelerating feeling up of the pit. The reason behind this is that most of the surveyed HHs (n=50), 90% of these HHs had their squatting slabs either with a raised rim which doesn't allow water to go into the squatting hole or sloped slabs from the squatting hole elevated towards the slab ends.

See the attached document with pictures...

Regards,

Dear Beda,

Thanks for your interesting question and the photos of pretty dodgy looking toilets... Were they built without a roof from the start or did they lose their roof over time?
I am guessing the filling rate might be influenced by rain events if:
- you have very high rainfall
- the floor slopes towards the drop hole and it doesn's have a raised rim
- the ground conditions are such that water is not infiltrating into the soil well

Is this the case in your situations? Have you found any publications through the usual means yet (like Google Scholar and alike)? If so, please do report back, as it would be interesting to know what you found.

Regards,
Elisabeth

Greetings!
I am during a study here in Dar es Salaam, Tanzania looking at the unroofed pit latrines vs the pit filling rate, especially in wet seasons.
Any contributions, thoughts or papers that you have come across regarding the topic?

Thanks!