In Tamale (Ghana) we are working on a solid free sewer network in a low-income area

  • Gert
  • Gert's Avatar
    Topic Author
  • Posts: 8
  • Likes received: 4

In Tamale (Ghana) we are working on a solid free sewer network in a low-income area

In Tamale (Ghana) we are working on a solid free sewer network in a low-income area in the centre of the city, Salamba and Sakasaka. We build / renovated a waste water treatment (septictank, ABR, trickling filter) for about 6000 people (including 1000 school children and 350 school resident students of a nursery school).
Last month we are started to lay the small diameter sewer lines and are making the first connections. 1,5 kilometer of sewer pipes have been manually laid within 3 weeks with unskilled labourers.

SDoon we we will be posting a report on our experience. The project partners are PerfSan Ltd (Ghana), Daily Business/WASTE (The Netherlands) and GMB (The Netherlands). The project is partly funded by ViaWater.

The WWT has an capacity of 6000 people IF they use 1 liter water per flush. People are happy with that, because of the water shortages and price. We have under estimated the supply of pour flush options: scatting pans, soft S traps etc.

Where can we find (in Ghana) equipment to serve our purpose. We are also open to use solutions that we have to make from existing other materials.

Gert
The following user(s) like this post: DhwaniShah
You need to login to reply
  • Gert
  • Gert's Avatar
    Topic Author
  • Posts: 8
  • Likes received: 4

Re: In Tamale (Ghana) we are working on a solid free sewer network in a low-income area

Dear Kevin, (and others)
Sorry for not being in contact since we started to construct the WWT and network in Tamale (Ghana). The project is moving slowly but steadily. We added a ABR between the settling tank (which we changed in to a septic tank, and the aerobic filter that we concluded later work very well. So we decided to clean it and change the filter media with bettre local material; vulcanic rocks and plastic scrapnel. It running at its full capacity (40 m3 / day) and we started to test the effluent quality. We estimate that the WWT will be abel to serve about 6000 people.
More than 1,5 kilometer of small diameter (though we remained conservative) have been laid and we started to connect households.

As you predicted the willingness to connect imprive very slow, but now peoople can show neighbours the system and the opotion to connect the existing septic tanks help a lot. Yes, it remains a challenge, but the PerfSan teanm has been was strengthened by a clever female collegue with to work with the families and she is doing well.

The other challenge is the minimize the water use. As you might have seen in an other posting today we are looking for pour flush option.

During breakfast today, we came came up with the following assumption which we hope to get feed bak on from the SUSANA community.
The influent into the interceptor tank (adapted water polytank) is a 90-elbow. The pipe from the toilet to the interceptor has a good ventpipe (4 inch, 2-3 meters high). See images.

We assume that the ventilation will allow us to install scat pans / toilet without water-lock / stench trap (goose-neck).
Attachments:
The following user(s) like this post: DhwaniShah
You need to login to reply
  • muench
  • muench's Avatar
  • Moderator of this Forum; Freelance consultant and Wikipedian (former roles: program manager, lecturer, process engineer for wastewater treatment plants)
  • Posts: 2561
  • Karma: 52
  • Likes received: 718

Re: In Tamale (Ghana) we are working on a solid free sewer network in a low-income area

Hi Gert,
Welcome back to the Forum! In my role as moderator I try to ensure that no post that should be answered is left without an answer... For this reason, I have moved your two posts into this new thread as I think they belong together.

You wrote:

Where can we find (in Ghana) equipment to serve our purpose.


Which equipment do you mean? Do you mean pour flush sitting or squatting toilets? Maybe with the SaTo pan which appears to be quite popular these days? Have you already found what you were looking for?

And which design assumptions exactly did you need feedback for?

Also, which project is this, what is its scale and how is it funded? I see you are now a Senior Advisor with Daily Business which is established to support Bottom of the Pyramid business development for urban sanitation and waste management in fast growing cities. (according to your LinkedIn profile). Is that a consultancy firm?

Regards,
Elisabeth

Community manager and chief moderator of this forum
funded via SEI project until January 2019 ( www.susana.org/en/resources/projects/details/127 )

Dr. Elisabeth von Muench
Independent consultant located in Brisbane, Australia
This email address is being protected from spambots. You need JavaScript enabled to view it. Twitter: @EvMuench
Sanitation Wikipedia project leader: en.wikipedia.org/wiki/Wikipedia:WikiProject_Sanitation
My Wikipedia user profile: en.wikipedia.org/wiki/User:EMsmile
You need to login to reply
  • DhwaniShah
  • DhwaniShah's Avatar
  • Posts: 2
  • Likes received: 0

Re: In Tamale (Ghana) we are working on a solid free sewer network in a low-income area

Dear Gert,

Since you are implementing this project you must have researched on it before.
Request you to share few case studies on settled/solid free sewer.
I would like to know more about it in detail.

Dear Elisabeth,
It will be really helpful if you also share few case studies on it.

Thank you.

Regards,
Dhwani
You need to login to reply
  • Gert
  • Gert's Avatar
    Topic Author
  • Posts: 8
  • Likes received: 4

Re: In Tamale (Ghana) we are working on a solid free sewer network in a low-income area

Dear Elisabeth and Dhwani,

The problem we had when we started the project that Kevin Tailor was the only person I knew who had any practical as well as knowledge of soem other interceptor sewer projects. The literature on this kinf of sewer network is very scarce. We did not find much information that was practical and provided enough details. I had work with Kevin in Palestine on a similar project 20 years ago, and in since that days few other project had been implemented. The advantages of this kind of sewer systems seemed obvious to us, but we could not answer the question why it had not been implemented more. As we are in the last phase of our project, we did not meet substantial reason (yet) why the system has not been tried elswhere.
Soon we will be able to share details of our project.
As for the toilet 'seats' we are looking for: Yes we are familar with the SatoPan. And I think that it is the best option for the Muslim community of Salamba (Tamale) where we laying the network. So far we did not find pour flush toilet in Ghana. But we would be glad to find them.

The project serves 3000 people (including a school with 1000 pupils and vocational school with 350 resident students). More on the project can be find on www.viawater.nl/projects/ghana-settled-s...k-sakasaka-in-tamale . The project information needs to be updated and that will happen soon.

The assumption we are testing is: a ventpipe vertically connected on the sewer pipe from thetoilet to an interceptor (or septic tank) will allow you to install scat pans / toilet without water-lock / stench trap (goose-neck). If anybody can confirm that (or not) based on experience we would appreciate that.
You need to login to reply
  • goeco
  • goeco's Avatar
  • Self employed innovator with an interest in wastewater treatment systems and recycling of nutrients
  • Posts: 225
  • Karma: 7
  • Likes received: 117

Re: In Tamale (Ghana) we are working on a solid free sewer network in a low-income area

I'm surprised that such a project would be undertaken (apparently) in the absence of being adequately informed. Can I assume that "innovative" in this context means by being "in the dark" about the options, just try out ideas and then ask questions later? There doesn't seem to be any information provided on the website, nor provided here.

I haven't picked up on the advantages of this specific type of system yet and would appreciate being enlightened on these. Disadvantages I see by using septic tanks at the household to intercept the solids, include:
  • a costly problem (sludge) that needs to be dealt with later;
  • unnecessary generation of greenhouse gases. At this scale utilisation of methane gas is unlikely; and
  • Using a septic tank for intercepting solids is effective but costly. A small "interceptor tank" would require regular removal of sludge, which inevitably will not happen.

So far this doesn't come across to me as a sustainable solution at all. Details please...

I assume the idea is to reduce the cost of the sewer network. The tradeoff is between the cost of the treatment plant (per person) and the cost of conveyance (per person). Data please on the technologies considered. So will this then discharge to a waterway or to land? Context please.

Are the costs of installing and maintaining septic tanks outweighed by the reduced costs for conveyance pipes? I would suggest not. Well... perhaps for a while, but how long? Treatment plants have sufficient scale to (cost effectively) produce (adequately) treated solid and liquid waste. In this case, equipment would be required to extract the sludge from the septic tanks and an additional facility would be required to treat the sludge. Has vermidigester technology even been considered for interception? If not why not? This is by far the lowest cost option to remove solids from wastewater at source and produces easily handled humus rather than sludge. Paradigms fall slowly, from the weight of repeated failure... was this a lost opportunity for true innovation?

Dean Satchell, M For. Sc.
Go-Eco Sustainable Solutions
www.go-eco.co.nz
You need to login to reply
  • goeco
  • goeco's Avatar
  • Self employed innovator with an interest in wastewater treatment systems and recycling of nutrients
  • Posts: 225
  • Karma: 7
  • Likes received: 117

Re: In Tamale (Ghana) we are working on a solid free sewer network in a low-income area

Hi Gert,
If you don't have a water lock you will need active ventilation in your ventpipe if the toilet is indoors. Active as in positive pressure at all times (e.g. fan), otherwise you will get odours from the anaerobic digestion in your interceptor/septic tank. A water lock is the simpler way to go and although that requires more flush water than e.g. sato pan, you could reuse handwash water for that.

cheers
Dean

Dean Satchell, M For. Sc.
Go-Eco Sustainable Solutions
www.go-eco.co.nz
You need to login to reply
  • JKMakowka
  • JKMakowka's Avatar
  • Just call me Kris :)
  • Posts: 941
  • Karma: 35
  • Likes received: 304

Re: In Tamale (Ghana) we are working on a solid free sewer network in a low-income area

Gert wrote: The WWT has an capacity of 6000 people IF they use 1 liter water per flush. People are happy with that, because of the water shortages and price.


While I think solid-free sewerage is an interesting technology in certain circumstances, it would seem that which such a low flow it is not necessary to remove the gray & black water from the plots? You might also run into significant smell problems from the sewers if the water basically dries up in the pipe due to low flow.

Microbiologist & emergency WASH specialist
WASH news aggregator at: news.watsan.eu
You need to login to reply
Share this thread:
Recently active users. Who else has been active?
Time to create page: 1.622 seconds