Maybe also look for nearby bar / nightlife areas as people tend to urinate publicly close to these (putting up mobile urinals on the weekends can really help with that).
For the overall hydrology of the lakes the local sewerage utility might have a run-off simulation or at least a higher resolution elevation map.

Looking forward to the results.

Hi Jorgen

Superb, thank you - if we move beyond the next stage, we will certainly be keeping you in mind.

We have an inspection of the lakes and gardens area tomorrow, where we plan to collect sufficient data to prepare a full presentation to the Council.

That presentation will include a proposal that the Council contract our team to conduct a full survey including water, pollutant, pathogen and other samplings.

We already know they have significant sludge buildup and algae blooms, so there are concerns with the water quality - the core is that they don't know exactly what's going into the lakes (including from the public toilets) and therefore how to wholistically manage those inflows.

For all; I have attached the Inspection Record we intend to use for this Inspection to this thread for Susana members to review and suggest any improvements

Hi Dennis,

If you want to convert to another waste management system without changing the whole infrastructure, you may sanitize the blackwater with ammonia and then use it as a fertilizer. This requires you to convert the sedimentation-separation septic tanks to closed septic tanks with no outlet, but otherwise you can use the same toilets. When a tank is full, you can add some urea (e.g. 1 %) and let it stay for a time (e.g. 1 month), after which the pathogens are inactivated and it can be used as a fertilizer. During this time you will need another tank for alternate filling.

There is no risk of spreading pathogens to the water ponds in the park with this type of closed-system. Furthermore, all the nutrients in the excreta can be recycled and used in agriculture. The main constraint is probably the cost of transport of large volumes of treated blackwater to the fields. Furthermore, if the toilets are using large flushwater volumes, then the existing septic tanks may not have sufficient storage. In order to avoid the ammonia escaping to the air, which will cause a bad smell, it is crucial that the tanks are airtight.

Higher urea dose cause faster inactivation of pathogens, and hence a shorter storage time can be applied. The urea dose can therefore be adjusted to achieve the desired storage time. However, higher urea doses than 2 % is not recommended from environmental point of view, and shorter storage time than around 2 weeks is not possible at ambient temperatures.

Here are some reports about the technology and its use in Sweden, although here is normally the storage facility located at the farm.

Blackwater sanitization with urea in Sweden – sanitization effect and environmental impact stud.epsilon.slu.se/6945/1/vidal_b_140630.pdf
The potential for self-sanitisation of faecal sludge by intrinsic ammonia
www.sciencedirect.com/science/article/pii/S0043135413005988
Presentation at FSM3: Inactivation of Ascaris Eggs and Salmonella spp. by Ammonia
www.susana.org/images/documents/07-cap-d...1/2-1-5-1-Nordin.pdf


We are several people working with this technology in Sweden, and as we would like to see more applications of the technology worldwide, we will gladly share our experiences with you.

Best regards
Jörgen Fidjeland

Hi Dennis

Just don't give up so easily on the BioFizz. This is a South African product and the researchers there are renowned, self disciplined and serious.

Kindly contact them at:

CSIR Biosciences
Pretoria
South Africa
Telephone: +27 (0)12 841 3260
Facsimile: +27 (0)12 841 3561
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
OR visit www.csir.co.za

Best regards / Mwaniki

And this is why we participate in fantastic forums like susana!

Thank you Elisabeth*, just saved me time can go to more productive things:)


+++++++

* For this post: forum.susana.org/forum/categories/53-fae...it=12&start=24#11976

Hi mwaniki

Biofizz could be useful


Went to csir site but not much info on case studies

Any idea how to buy for testing?

Seems like a possibility for much wider use if effective

Hi Dennis

Kindly take note of a new product called BioFizz, which a biological product formulated
to treat septic tanks. Could it be of help? Please check details in the latest edition of Africa Water, Sanitation & Hygiene Jan-Feb 2015 page 15.

Regards / Mwaniki

Thank you marijn and mughal

Will include storm drain mapping and Condition in study, along with soil structures and other suggestions

Dear Dennis,

If that problem were to occur here, the municipal authorities would take following action, assuming the park is extensively used by children and women:

1. Clean the stormwater drains. Here, stormwater drains are cleaned before the onset of wet season. Replace damaged stormwater pipes when cleaning does not help. This equally applies to sewer pipes. Replace the damaged sewer pipes.
2. If you want to reuse the effluent, be careful with anaerobic system, if you prefer that. Anaerobic system emits rotten egg-like hydrogen sulfide gas – remember, you have children at the park. You would need aeration as last step, to increase DO level of the effluent.
3. I assume that the park has a proper stormwater conveyance system, with favorable contours that facilitate flow of rainwater to stormwater drains, with no hindrances.

Regards,

F H Mughal

Dear Dennis,

Overflow during the monsoon, seems to suggest that there are storm water drains that end up in the septic tank. I would see that as a first priority to solve.

Further, I think Chris's suggestion of ABRs, is sound. If water recycling for flushing or planted reed beds are not an option for the city council. You may consider some subsurface infiltration in sand trenches. But that would also depend strongly on the local hydrology.

Considering that these are public toilets and that Malaysians seem to like using a lot of water for cleaning them. I would think that a simple and robust wet system would be most appropriate.

Regards

Marijn

Thank you Chris

I will get maps and layouts (there are several toilet blocks), so we can see the overall picture

Budget range available is reasonable, is just a matter of justifying any recommendation with rational reasoning

Interesting study using insects for the water quality research; have started to review

Hi Dennis,

How much space is available in the park?
What sort of budget is available?
How many users on the average day? ... and the peak day?

I would suggest UDDTs (with lots of educational material and attendants all the time), but it might also be a good case for recycling flush water after treating it via anaerobic digestion (e.g., ABRs) and vegetated sand filters
forum.susana.org/forum/categories/40-gre...ructed-wetland#11393

... and it would be a great place for exercise equipment that pumps the treated water back up to the overhead tank.

( By the way, my student intern did a great study using aquatic insects and other macroinvertebrates to measure water quality and found big impacts of wastewater discharges. She also looked at less toxic alternatives to chlorine bleach ... and a traditional mix of ashes and plants whitened clothes better than chlorine:
issuu.com/chriscana/docs/allie_isp_ece_fa14_rowe_final.docx
Spanish presentation: t.co/Fx93we29Af B) )

Best wishes,
Chris Canaday