Elisabeth Just before I retired, we initiated a contract to start collecting and processing all the contents of the UDDT's in Durban. This is linked to a black soldier fly processing initiative that is funded in part by the Gates Foundation, as not all the contents can be processed in the Ladepa plant that is used to produce plant nutrients from the faecal sludge collected from the VIP toilets here. If this contract has not yet started, it must be about to begin - I will try and get a progress report for you. This will possibly mean another update of the Wikipedia page. Regards Neil Macleod

Dear Elisabeth,

Thank you for initiating this topic!

I can add a little more background to how the miasma theory contributed to the abandonment of nutrient recycling in England. It was a confluence of several historical factors - the state of scientific knowledge, colonisation that enabled alternative guano-fertilizer to be sourced, the abundance of water at the time …
(I’m copying from an article I wrote, and attaching a diagram that shows how the timing made this possible).

A series of cholera epidemics ravaged London in the 1800s focusing public attention towards solving urban public health problems. The well established medical theory about the cause of these and other diseases was the inhalation of miasmas or malodorous disease-causing vapours, so that removal of decomposing miasma-causing substances as promptly as possible appeared a logical strategy for improving public health. To use water as a transport medium for effecting this rapid removal was feasible, since water resources were abundant due to relatively high precipitation rates in Europe at the time, and stormwater drainage canals already installed in early industrialising cities could be used for movement of wastewater. Water-carriage technology was also desirable, because its automation represented advancement in scientific and economic terms, since economic growth has generally been equated with the substitution of human energy by other forms of energy. Finally, although the dilution of nutrients in large volumes of water made agricultural reuse difficult, the availability of alternative fertilizers in imported guano and nitrates around this time made it possible to abandon attempts at recycling wastes for agriculture.

The timing of the contextual factors had a vital influence on the outcome of the sanitary revolution, and it is intriguing to speculate how a different context might have turned out. In particular, if the germ theory had been established at the time, whether mixing and dispersing disease-causing germs in water might have appeared less logical. Or, whether discarding excreted nutrients would have been possible, if alternative fertilizers had not become available right at that time.

Warm regards,
Kumi

Whilst taking the problems mentioned above regarding the reuse of sewage sludge, I just wanted to share this link from the official British government handbook on using it in agriculture. This illustrates that when using the digested cake on Winter wheat crops, no further inorganic P is needed to meet requirements of the crop - and also puts a financial value on using the extreta as fertiliser.

adlib.everysite.co.uk/adlib/defra/conten...doc=262994&id=263072

Of course, as discussed above, sewage sludge is not the same as fresh excreta, there is an issue with metals and other contaminates and so on. But there is a genuine agricultural value in reusing the treated sludge from an industrial sewage works.

Also, of course, the characteristics of urine or untreated (or differently treated) excreta is going to be different.

NPK (nitrogen, phosphorus and potassium) are all macronutrients important for agriculture.

Peak Phosphate is discussed as (opposed to Peak Nitrogen) because of the different way that the nutrients behave in the environment. Nitrogen is indeed high in urine as urea, but unlike phosphate there are other ways to get nitrogen ions into the soil (for example some plants are able to get it directly from the atmosphere). In contrast, phosphate can only be obtained from rock phosphate (ie mined) or reused.

In one sense the Peak Phosphate discussion is an economic one (about the future supply of rock phosphate) which is a bit irrelevant, given all of the phosphate which is being washed into the seas and causing an environmental problem - and which could be collected and reused. Even if it doesn't run out, there is still a big negative in terms of the Planetary Boundary of inefficient use.

Another point is that the excreta needs to supply the needs of the plants. Many soils are actually short of P, so the limiting factor for plant growth might be P rather than N. Applying more that is actually being used may just lead to the nutrients being washed out of the soil (or lost to the atmosphere) and causing a problem somewhere else.

It was actually in an old book, but there is some information online such as this page: www.1900s.org.uk/outdoor-privy.htm

Interestingly, that link suggests that the waste was collected by a night-soil man.

Are these texts that you are reading available online or only paper based? Sounds interesting, I would like to include relevant bits in the relevant Wikipedia articles.

I should perhaps start a "history" section on the page about "dry toilets":
en.wikipedia.org/wiki/Dry_toilet

(rather than putting everything only in the history section of the ecosan page:
en.wikipedia.org/wiki/Ecological_sanitation#History)

Over the last few weeks I have been reading a local history of British dry toilets, which continued in some areas (interestingly, often in urban areas) through to the 1940s. It seems that these were often emptied directly onto the gardens of owners.

At the risk of drifting slightly of topic here maybe I should try just to clarify what I meant.

Firstly, the introduction of water flushed sewers made the reuse of excreta in agriculture more difficult due to the massively increased volumes of material and the very nature of the wastewater transported (mixed flows of unknown origin). Even the sewage farms (which were not a universal part of early wastewater treatment systems) had problems dealing with the volumes. And what were originally farms using wastewater transformed with time into something else and were not used for agricultural production. Here is a good example: beddingtonfarmlands.org.uk/1998-2008/4535562136

Secondly, sewage sludge spreading is again something different from using wastewater for irrigation and a pretty controversial topic. I personally see it more as a poor solution for the solid waste problem for wastewater treatment plants and certainly not a convincing example of nutrient recovery from human excreta.

And thirdly, the fact that the social reformers were not willing to accept the fact that lives were cheap is what lead to the end of the terrible social and working conditions of the time. These poor conditions and the political will to change them drove change.

bracken wrote:
Regarding sewage farms, the sewage collected in Victorian London was actually discharged into the Thames estuary and not reused on farms. ("Contrary to Chadwick's recommendations, Bazalgette's system, and others later built in Continental Europe, did not pump the sewage onto farm land for use as fertilizer; it was simply piped to a natural waterway away from population centres, and pumped back into the environment." from en.wikipedia.org/wiki/Sewage_treatment).

Sewage certainly was pumped into the sea, but several sewage farms were in operation in London and Royal Commissions from the 1850s actually recommended reuse on the land to protect waterways. See this: www.sewerhistory.org/articles/trtmnt/1910_abs503/article3.pdf

The sewage farms were used towards the end of the 19th Century rather for inland towns where disposal at sea or into a water body was not an option - it was not the direct application of human faeces on fields but the use of sewage effluent on fields, which is something quite different I would contest.

True. And indeed throughout the 19 century the worry was as much about managing the industrial effluents in the sewage rather than the faeces itself.

Even these though became overloaded as the population increased and the land many of them occupied was then used to build more efficient sewage works (and possibly retained the name "sewage farm" although no farming continued on the site).

It is not clear what you mean here. Landspreading of sewage sludge from sewage works is a common disposal mechanism of treated faeces in England.

I would dispute that people were that cheap in Victorian London, given the political power of the social reformers, including Chadwick, and writers such as Dickens, and the way in which society was transformed by them.

Well, I'm sorry that is just wrong. Throughout the 19 century the working poor were seen as disposable and were engaged in occupations which it was known would lead to serious illness and death.

For example in the matchmaking industry, Dickens highlighted the damaging effects of white phosphorus matches in the 1850s but they were continuously manufacturered through to 1910 - even though there was much evidence of health damage to workers. There were many occupations where conditions were so dangerous that people were expected only to survive for a few years.

Although I didn't single Britain out as faecophobic I could imagine that there is probably some kind of sliding scale between cultures who are more open and willing to use faeces in productive systems, to those who want absolutely no contact or reminder of the fact that faeces come from the human body. I'd have no idea where Britain would fit on that scale but probably somewhere between the extremes, tending more to the rejection side slightly.

Regarding sewage farms, the sewage collected in Victorian London was actually discharged into the Thames estuary and not reused on farms. ("Contrary to Chadwick's recommendations, Bazalgette's system, and others later built in Continental Europe, did not pump the sewage onto farm land for use as fertilizer; it was simply piped to a natural waterway away from population centres, and pumped back into the environment." from en.wikipedia.org/wiki/Sewage_treatment). The sewage farms were used towards the end of the 19th Century rather for inland towns where disposal at sea or into a water body was not an option - it was not the direct application of human faeces on fields but the use of sewage effluent on fields, which is something quite different I would contest.
Even these though became overloaded as the population increased and the land many of them occupied was then used to build more efficient sewage works (and possibly retained the name "sewage farm" although no farming continued on the site). I would dispute that people were that cheap in Victorian London, given the political power of the social reformers, including Chadwick, and writers such as Dickens, and the way in which society was transformed by them.

I'd dispute this idea that there is faecophobia in the UK. Land application of human faeces has never stopped. It has been continuing from the middle ages including during both world wars until the present day. Sewage farms are a documented part of the British landscape for at least 150 years.

The stink and the idea of miasma led to the construction of sewers in London but I think this was more of a transportation issue than because they understood it in terms of it as a source of pathogens. People were cheap in Victorian England, and people were still required to work the faecal wastes on farms.

Hi Sebastian,
Just to clear up what you said in your second point.
The discoveries of Snow (1854) and Pasteur (also mid 1800s) almost certainly DID NOT initially contribute to the collapse of the reuse system, as the germ theory was not widely accepted at the time that Bazalgette's work on London's sewer began (subsequent to the Great Stink of 1858). Just check out the Lancet's own editorial on Snow's discovery:
www.ph.ucla.edu/epi/snow/reactionandcommitteeaction.html

It was the Great Stink that moved the British Parliament to commission the construction of the first modern sewer, not the Broad Street Pump affair and discovery that cholera was water borne. And the modern, water flushed sewer is something that made nutrient recovery much more difficult.
I would agree though that germ theory did eventually (certainly by the turn of the century) lock in the water-borne sewer and encourage widespread "faecophobia".