the suburbs of Paris until the 1960s. Concerning the prospective for 2020–2100,
the methodology is described in Sect. 4.
2 Resource-Oriented Management Leading to Circularity
(1800–1905)
2.1 Intention Without Achievement (1800–1868)
At the beginning of the nineteenth century, our figures show extremely low rates of
circularity in human excreta management: 4% for N and 8% for P in the 1800s. The
rest of N and P is mainly lost at three different stages: (1) just after excretion if
excreta are not stored for collection, (2) during storage and (3) in the treatment
process.
Some human excreta are abandoned in public and private spaces, even though
this practice had been forbidden for centuries – unsuccessfully – and construction of
cesspools for each house was mandatory before the sixteenth century [23]. When
human excreta are stored in cesspools, only very little of it is eventually collected
since leakages lead to transfer to soil and underground water. Cesspool watertightness is for the first time enforced by a decree in 1809 [23]. The proportion of leaking
night soil has probably decreased since then, but in 1858, tremendous concentrations, between 29 and 300 mgN/L, were still reported in underground water [24].
Human excreta treatment processes are the third major cause of inefficient
recycling. In the eighteenth century, the Paris authorities required that night soil be
stored for 3 years before being applied to agricultural land, in order to guarantee
salubrity. There is evidence, however, of many farmers being sued because they
spread night soil directly on their land [23].
3 In 1781, night soil had to be transported
to a single facility called the voirie de Montfaucon (Fig. 2). The drying process
implemented in 1787 by Jacques Bridet created a greatly appreciated fertiliser called
poudrette where nutrients are highly concentrated. But the overall efficiency of
uptake of nutrients from the night soil content to the final poudrette product was
low: before 1844, most liquids were evaporated, infiltrated in the soil or discharged
to surface water, together with their N and P content, with specific volatilisation of N
in the form of ammonia. Therefore, 90% of N is estimated to be lost in the
process [23].
Although regulations tended to favour circularity, the actual materialisation of
human excreta management in Paris led to major pollution of soil, underground and
surface water and air and a very low recycling rate. Between the 1800s and the
1860s, however, there were major changes and numerous innovations in human
3 This practice seems common in some places in the countryside but also in urban areas such as
Grenoble and Lille [25]. In these areas, the circularity of the process of night soil treatment is
probably very high through direct application of liquid night soil and all its N and P content.
Past and Future Trajectories of Human Excreta Management Systems: Paris. . .
123
the methodology is described in Sect. 4.
2 Resource-Oriented Management Leading to Circularity
(1800–1905)
2.1 Intention Without Achievement (1800–1868)
At the beginning of the nineteenth century, our figures show extremely low rates of
circularity in human excreta management: 4% for N and 8% for P in the 1800s. The
rest of N and P is mainly lost at three different stages: (1) just after excretion if
excreta are not stored for collection, (2) during storage and (3) in the treatment
process.
Some human excreta are abandoned in public and private spaces, even though
this practice had been forbidden for centuries – unsuccessfully – and construction of
cesspools for each house was mandatory before the sixteenth century [23]. When
human excreta are stored in cesspools, only very little of it is eventually collected
since leakages lead to transfer to soil and underground water. Cesspool watertightness is for the first time enforced by a decree in 1809 [23]. The proportion of leaking
night soil has probably decreased since then, but in 1858, tremendous concentrations, between 29 and 300 mgN/L, were still reported in underground water [24].
Human excreta treatment processes are the third major cause of inefficient
recycling. In the eighteenth century, the Paris authorities required that night soil be
stored for 3 years before being applied to agricultural land, in order to guarantee
salubrity. There is evidence, however, of many farmers being sued because they
spread night soil directly on their land [23].
3 In 1781, night soil had to be transported
to a single facility called the voirie de Montfaucon (Fig. 2). The drying process
implemented in 1787 by Jacques Bridet created a greatly appreciated fertiliser called
poudrette where nutrients are highly concentrated. But the overall efficiency of
uptake of nutrients from the night soil content to the final poudrette product was
low: before 1844, most liquids were evaporated, infiltrated in the soil or discharged
to surface water, together with their N and P content, with specific volatilisation of N
in the form of ammonia. Therefore, 90% of N is estimated to be lost in the
process [23].
Although regulations tended to favour circularity, the actual materialisation of
human excreta management in Paris led to major pollution of soil, underground and
surface water and air and a very low recycling rate. Between the 1800s and the
1860s, however, there were major changes and numerous innovations in human
3 This practice seems common in some places in the countryside but also in urban areas such as
Grenoble and Lille [25]. In these areas, the circularity of the process of night soil treatment is
probably very high through direct application of liquid night soil and all its N and P content.
Past and Future Trajectories of Human Excreta Management Systems: Paris. . .
123