Structured discussion on Septage Transfer Stations - Week 2 (1-7 July) Considerations for septage transfer stations

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Structured discussion on Septage Transfer Stations - Week 2 (1-7 July) Considerations for septage transfer stations

Dgroup discussion “Septage Transfer Stations”
Topic 2: General considerations for Septage Transfer Stations

Dear colleagues,

I hope that the first week of discussion on Septage Transfer Stations (or FS Transfer Stations if you want), created your interest to think more about this practical but essential element of city-wide FSM in many contexts. As I mentioned in the announcement, this second week of the discussion hopes to hear your ideas about the issues that should be considered to decide on STS or different options. The most important considerations when planning a transfer station are where to locate the transfer station and whether it will be mobile or fixed.

Of course we also still welcome more examples and if possible pictures of Septage Transfer Stations.

The second topic will run from today 1st of July till next Tuesday 7th of July, and we would like to hear your ideas and experience on any of the sub-topics below:
A. Siting a transfer station
B. Design considerations for fixed options
C. Operation and maintenance considerations
D. Financial considerations

While these considerations below are generic, we are keen to hear from you which considerations were taken into account in practice when constructing a transfer station:
1) Considerations for constructing a septage transfer station or not
2) Considerations for choosing a mobile septage transfer station and locations

Below a short introduction will be given to each of the sub-topics. You can contribute by replying directly to this message. For the benefit of other participants, please mention your name, organisation and country.

Looking forward to your ideas and contributions,

Ant.

A) SITING A TRANSFER STATION
Regardless of whether the transfer station is permanent or mobile, the siting of the transfer station requires careful planning in order to optimise transport time and costs, maximizing the coverage area, and taking into account the needs of customers (size of their tanks, emptying frequency etc.). Accessibility and parking places for vehicles is also important, as well as acceptance and reducing nuisance for the neighbourhood.

B ) DESIGN CONSIDERATIONS FOR FIXED OPTIONS
A number of key technical considerations for septage transfer station are:
• Size and volume of the tank to match servicing requirements
• Health and safety of management, and possible spillage/ accidents.
• Ease of discharge access and emptying
• Safety for the public

In the case of fixed transfer stations, this is illustrated in the figure below. Fixed holding tanks can take various forms, from large plastic containers to more expensive concrete chambers, and can be located above or below ground. The structural components of a fixed facility must comply with all relevant municipal building codes. Of particular importance is to counter buoyancy forced in instances where the underground tank is located in an area with high ground water table.

C) OPERATION AND MAINTENANCE CONSIDERATIONS
Operation, maintenance and management of a transfer station can be undertaken by either public or private institutions. The roles and responsibilities would include the security of the facility from vandalism and illegal use, controlling access, maintaining the functionality of the facility and ensuring that the facility is maintained in an hygienic state. To avoid indiscriminate dumping of toxic waste in the facility, only registered emptying contractors should be permitted to use the facilities.

Regular maintenance activities would include:
• Cleaning of garbage screens to ensure a constant flow and prevent blockages, flies and odours The screenings should be stored in proper containers and transported to a designated landfill.
• Washing down and cleaning of the discharge chute.
• Cleaning of the general loading area to minimise odours, flies and other vectors from becoming public nuisances.
• Deal with compacted dry sludge at the bottom of the tank (in some cases).

D) FINANCIAL CONSIDERATIONS
Transfer stations are rarely operated as an independent financial entity, rather they are part of a bigger emptying, transfer and treatment service and need to make financial sense in that context. To develop the business case for a transfer station, costs[1] associated with the capital and ongoing operation and maintenance need to be considered, along with an analysis of potential cost recovery options.

P.S. I have some technical problems uploading the pictures. Will do that tomorrow.

Antoinette Kome
Global Sector Coordinator WASH

SNV Netherlands Development Organisation
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Re: Structured discussion on Septage Transfer Stations - Week 2 (1-7 July) Considerations for septage transfer stations

Dear All,

In this second week on considerations for septage transfer stations, the following two contributions were posted on the Dgroup, from Aftab Opel in Laos and from Reinilde Eppinga in Kenya.

best,
Ant.

From Aftab Opel:
Dear Group,

I think it depends on various aspects whether to go for fixed or mobile transfer station. In cities and towns where land is so precious and unavailable (Dhaka), mobile transfer stations might be the good option while low dense cities (Vientiane) fixed transfer stations could still be a good possibility. However, they have to be carefully planned for in the city master plans. One of the major problem facing the city of Dhaka is that the need of FSM has not been thought about when they the master plan was developed and approved.

I also have a question to the group – cannot we think about small scale treatment plant instead of fixed transfer stations?

I don’t have proper technical expertise so my comment on design options might be very shallow but I also think that design option largely depends of the characteristic of sludge – if most septage is coming from ‘proper’ septic tank, the design option will have less emphasis on effluent management. In addition to the point below for design option, I would also emphasis about the location – I know one organisation in Bangladesh spend a lot to construct a treatment plant but it could not run for a single time due to public protest as people were expecting it to be odorous and did not let it run.

• Size and volume of the tank to match servicing requirements
• Health and safety of management, and possible spillage/ accidents.
• Ease of discharge access and emptying
• Safety for the public

On O&M and finance – to me, it depends largely on the business model.

I hope, it helps.

With kind regards

Aftab

Aftab Opel

Sector Leader
Water, Sanitation and Hygiene
SNV – Netherlands Development Organisation
Vientiane, Lao PDR

From Reinilde Eppinga:
Dear Group,

I am Reinilde Eppinga, SNV WASH Advisor in Nakuru, Kenya, and would like to share practical experiences and
challenges related to Septage Transfer Stations or as we have labelled these: Primary Collection Points (PCPs)
(see photo attached).

The Nakuru County Sanitation Programme aims to demonstrate and upscale an innovative value chain
(SNV is focusing on the end of the value chain and is a partner in this 4-year EU-funded project implemented
by the local water company (NAWASSCO) and coordinated by Vitens Evides International (VEI)).
The project includes hygiene awareness, marketing of sanitation options, temporary storage of sludge in Low
Income Areas, transportation, treatment and re-use of waste in the form of faecal matter and urine products.
We are currently exploring bio-fertilisers (vermi-compost and Struvite) and bio-fuels (briquettes and pellets).

The past two years we have been working on the entire value chain. One of the main challenges has been
how to remove sludge from the Low Income Areas (covering over 371,000 people who mainly have pit-latrines
and septic tanks – less than 20% of the entire Nakuru population is connected to the sewer).

This includes technical, financial, political and social challenges. Most of these have been addressed and we are
currently planning for the first pilot of the Primary Collection Point. The PCP has been constructed locally with
locally available materials and expertise; NAWASSCO is exploring a percentage increase on the sanitation tax to
co-subsidise the costs involved while landlords and house-owners will pay for the pit-emptying; the Public Health
Department has been extensively consulted, the Natural Environment Management Authority (NEMA) engaged for
an Environmental and Social Impact Assessment (ESIA), and a community forum organised for local buy-in.

The intended process: The PCP is a tank on wheels that can store 10,000 litres of sludge. It will be transported by a tractor from
the water company to a designated location within the Low Income Areas. It will be stationed there for a month (wheels are
removed so that it cannot be moved by external parties). An operator will man the station during working hours ensuring
proper operation and cleanliness. Pit-emptiers organised in Pit-emptying associations will use the gulper technology to empty
pit-latrines and transport the sludge to the PCP. When the PCP fills up an exhauster truck will empty it and transport the sludge
to the treatment plant. The empty PCP will be transferred to the next location. And the process will start again. A manual for
operation of the PCP has been developed which includes detailed information on each step described, including selection of
the site, community involvement, licensing and endorsement by Public Health etc.
We are currently exploring different options to take care of the solid waste/garbage found in the pits.

The project choose a mobile transfer station because of several reasons:
1. The area/Low Income Areas cover a significant population and one would need too many collection points if
one likes to ensure pit-emptiers have the convenience of a collection point near the to be emptied pits –
which reduces transportation/time costs. The current process requires only one or two mobile collection points
which can cover the whole of Nakuru on a yearly basis.
2. Land ownership, availability and cost is an issue. Temporary locations are easier to find than permanent ones.
3. Laws and regulations related to sludge transportation, storage and handling provide a challenge. As the PCP will
only be transported empty and clean challenges are reduced.
4. The community is more readily accepting temporary (one month per year) stationing of the PCP compared to
a permanent storage point.
5. The project will only consider a permanent collection point, if at the same site treatment and re-use can take place.
We are considering this in one of the Low Income Areas. The community could own the process of emptying,
collection, transportation, treatment and re-use options and develop this into a local business.

I will be happy to share more details, especially when the pilot is on-going.
Looking forward to learn from other countries and their practices.

Kind regards,
Reinilde Eppinga

Antoinette Kome
Global Sector Coordinator WASH

SNV Netherlands Development Organisation
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Re: Structured discussion on Septage Transfer Stations - Week 2 (1-7 July) Considerations for septage transfer stations

And this contribution was posted by Reza Patwary

Greetings, all!
This is Reza Patwary from SNV Bangladesh.

STS is a new concept in Bangladesh like in many other places. So, this post would be more about the thoughts on how STS would work best in the local context, than illustrating a successful implementation. The local context of Khulna, the third largest city in Bangladesh can be defined by: i. non-existence of sewage, ii. roughly 50:50 divide of household septic tanks and pit latrines, iii. high underground water level, iv. widespread connection of septic tanks or containments to the drains, v. high dependence on and preference to (less expensive) manual emptiers, vi. weak enforcement of sanitation regulations, and vii. low amount of municipal or sanitation tax, among others.

Site: Site selection of a STS may involve several considerations. First, the area could be residential, commercial or mixed. We have seen earlier that in residential areas of large cities, there often exist a water-pump run by city-WASA (Water and Sanitation Authority), protected by concrete and iron-grid and manned by a part-time caretaker in charge of the lock and key, who periodically visit the area to turn the pump on or off. That gives an indication why not choose a site and construct STS similar way, constructing an underground containment with port and lid adjacent to the road where small feeder vacutugs would pump-out their sludge and the larger vacutug would arrive time to time to pump-in the sludge from a deeper length of that containment with stronger motor. The odour is unlikely to spread out and the operation can take place throughout the day. The key point here is that the residential areas will need to have such open space or park. Second, in commercial areas which are relatively busier during the day, underground large containment or septic tank of a large commercial or administrative building or compound, with access port can easily be used as STS after the closing of commercial hours. Both vacutug-led collection of sludge from both the containments of the commercial buildings and the containments / septick tanks of the surrounding residential buildings can discharge into this STS containment, and later on, a larger truck can collect those sludge. Third, there are some areas that can be both residential and commercial where navigation of small or large vacutugs may remain a problem or where available space to construct a STS or use of any large constructed or existing containment would simply be impossible. In that case, either of the two options could be chosen: i. a large vacutug would be parked along the main road for few hours a day to collect all the sludge collected by the smaller vacutugs or ii. a covered container can be placed by the main road to accumulate the sludge from the smaller vacutugs. When the container gets filled it can later be mechanically lifted by a large truck and a new empty covered container may replace that one. Though not for collecting FS, this model is being practiced in the capital city of Dhaka for cleaning municipal solid waste.

Design: A STS can broadly be of two types: either static or mobile: The static STS would be a constructed one, preferably little elevated from the ground which of course may not absolutely guarantee that the STS would not be submerged under water after heavy rain or flood. These static STS or containments will have access port and lid and will have vent pipe. While small feeder vacutugs discharge in the containment, the larger vacutug will pump-out the liquids periodically and discharge the same in the treatment plant. The static constructed STS should consider the number of unloads every day. For instance, if the smaller vacutugs are of 1000 litres and there are 5 smaller vacutugs serving in the area and there are 5 unloads everyday, there would be 25000 litres of sludge collection every day the STS should be of a volume of 75000 litres – three times of daily collection so as to accommodate flexible planning of the larger vacutug to empty the sludge. The second option would be mobile STS either larger vacutug or a transportable covered container placed on roadside that will have a access port and lid on the top which can be transported to the treatment plant and can be emptied mechanically. These containers / vacutugs will have a capacity of 5000 litres and they will be transported out once they get filled. On a busy day these containers / larger vacutugs may make several trips to transport the collected volume of sludge from the area.

Operations and Maintenance: Like the most treatment plants, the STS also have to be managed by local authority while being operated by the community. In big cities in Bangladesh, kitchen garbage and night-time patrol is conducted by the community and the operation of the STS could become an added operation and part-time employment to some. The static STS could be managed by registering of the number and time of the unloads and the accumulated volume. When a point of particular volume is reached, STS attendant can call in a larger vacutug to pump-out and transport away to make room for pump-ins by smaller vacutugs to continue. The attendants will also collect tolls for each pump-in which would be adjusted from the fees paid by the institutional or household clients. The case of a mobile STS or a larger vacutug, it can also be parked in a particular location in a particular slot of the day to collect the pump-ins and later discharge the same at the treatment plant. The attendant to the static or mobile STS will strictly adhere to the spillage protocol and will have the storage of cleaning agents and washing facility to respond to those emergencies. Besides, the attendants will also observe the safety gears necessary while performing their duties.

Financials: Financial issues are closely linked to the governance and revenue mechanism – who pays whom. There are two major financial issues: i. construction of STS or purchase of large vacutugs; and ii. generating revenues for operations and maintenance. We can say while STS is in place, there would be broadly three different nodes of pre-processing FSM operation: i. household and institutional containments and collection and transportation of FS by smaller vacutugs, ii. transfer of FS to the STS, and iii. transfer of FS to the treatment plant. Collection and transportation is the end user interface where ultimate users of FSM services to be charged for services delivered. Part of this service fees are to be spent to operate the STS so that the STS operation (attendance to the STS site, registering of vacutug unloads and volume of sludge received, accumulated volume at the STS recorded and call for the larger vacutug) can run smoothly. While private sector or the communities can run the vacutug-based collection and transportation in a commercially viable manner, construction and management of the STS would be in most cases, municipality or community run semi-commercial affair where the operation of the STS would be financed viably from the collection fees of the smaller vacutugs in the area. Despite that, construction of STS would have to managed, controlled and/or invested by local authority to adhere to compliance and meet the goal of long term ‘social good’. Unlike processing plants, STS may not be used as a source for generating renewable energy, hence private investment would be limited. However, when the private vacutug operators in the area understand that the STS would significantly reduce their transportation cost to the out of the town treatment plant, they may well form a consortium of investors together with the local authority.

Antoinette Kome
Global Sector Coordinator WASH

SNV Netherlands Development Organisation
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Re: Structured discussion on Septage Transfer Stations - Week 2 (1-7 July) Considerations for septage transfer stations

Dgroup discussion “Septage Transfer Stations”
Summary Topic 2: General considerations for Septage Transfer Stations

Dear colleagues,

We have already come to the end of the second topic in this discussion about Septage Transfer Stations. We had three contributions: from Laos, Kenya and Bangladesh. I would like to thank all for their very interesting contributions. This is my short summary of the discussion:

Mobile or permanent transfer stations?
Aftab Opel from Laos suggests that the choice for a mobile or permanent transfer station could depend on the available space. In densily populated areas, such as in Dhaka, the preference may be for mobile stations, whereas in low density cities such as Vientiane fixed transfer stations could be an option. However, the general preference seems to be for mobile transfer stations because these seem to create less opposition, also in the experience of Reza Patwary from Bangladesh.

Also in the example given by Reinilde Eppinga from Kenya, mobile transfer stations are preferred because:
- It reduces investment costs
- Land ownership and availability is less of an issue
- Regulations are less of an issue
- Higher chances of community acceptance if the station is temporary

If mobile transfer stations are so highly preferred over fixed ones, it will be important to learn much more about technology and management options. The transfer station used in the case of Nakuru, Kenya, has interesting characteristics, in the sense that it can be moved by a tractor and that wheels can be removed when it is put into position.

Sludge transfer stations or small scale treatment?
Aftab asks whether small scale treatment could be considered instead of sludge transfer stations. Reza replies to this that small scale treatment would have higher O&M requirements than a transfer stations, and may also have higher land requirements. I think that this is also a financial question and that in different contexts different options could be explored.

Design considerations for sludge transfer stations
Generally transfer stations (and access to “inaccessible areas”) are not part of the urban sanitation planning process, while this is in fact an obstacle in providing services for all. As Shahidul Islam wrote in the previous block, in the recent technical assessment in our programme in Kushtia (Bangladesh) it was found that 20% of the roads could not be accessed by any vehicle, while another 20% could only be accessed by smaller Vacutug mounted on three wheelers. These are clearly not the type of vehicles that are going to transport sludge/ septage to a treatment plant. Aftab suggests that design considerations for transfer stations could be:
- Sludge characteristics/ water content, volume
- Ease of discharge access, emptying frequency and access
- Health and safety, management
- Safety for the public and other requirements to ease acceptability by the public.

Aftab adds the example of an organisation in Bangladesh spending a lot to construct a treatment plant but it could not run for a single time due to public protest as people were expecting it to be odorous and did not let it run. This underlines again that public opposition is almost a given in this type of works, and should be part of design considerations from the start. In a city in the Philippines that I visited recently, the opposition against the (large) treatment plant was overcome by creating a fund for neighbourhood development (as part of the tariffs) and giving preference to the neighbourhood population for jobs.

Best,
Ant.

Antoinette Kome
Global Sector Coordinator WASH

SNV Netherlands Development Organisation
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Re: Structured discussion on Septage Transfer Stations - Week 2 (1-7 July) Considerations for septage transfer stations

Dear Reinilde,

The Nakuru experience wrt transfer stations is quite insightful. I am already thinking of putting together a team from Kampala to come over and learn.

Would you be in a position to share knowledge products from the pilot? Besides pricing for the mobile STS, operations and management practices would present lessons for similar settings in the region - and beyond.

Best,
Fredrick

Fredrick Tumusiime, MSc
Independent Consultant
Water and Sanitation

Skype: tufre80
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Re: Structured discussion on Septage Transfer Stations - Week 2 (1-7 July) Considerations for septage transfer stations

Dear Fredrick,

I alerted Reinilde to your post (as she's not a suSanA member yet), and here's the reply she posted in the Dgroup for you:

++++++++++

Dear all,

Thank you Fredrick for your message and interest in a learning exchange.
Please note that the process of engaging the Public Health Department is
taking more time than expected and the pilot has not been implemented yet.

It would therefore take a bit more time before we can share knowledge
products from the pilot phase. We can however share the concept note
which details the planning of the pilot and answer any other queries you
might have at this stage.

Please send an email to: This email address is being protected from spambots. You need JavaScript enabled to view it. with a request and I'll reply as soon as possible.

Kind regards,
Reinilde

++++++++

Please give us feedback when you find out more or when you do that learning visit. Thanks a lot.

I will check with Reinilde if the mentioned concept note could also be posted here.

Regards,
Elisabeth

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Re: Structured discussion on Septage Transfer Stations - Week 2 (1-7 July) Considerations for septage transfer stations

Dear Elisabeth,

Thanks for the follow-up.

I will keep you posted wrt progress.

Best,
Fredrick

Fredrick Tumusiime, MSc
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