Engineering Rome

Comparing Water Sanitation in Ancient and Modern Rome

Engineering Rome 2019 – Student Report

Author: Benjamin Terry

Date of Publication: Sept. 24, 2019

Introduction

The main question I seek to answer in my report is this – who had better water sanitation, Ancient or Modern Romans? At first this may seem like a silly question; of course today’s water sanitation will be better than it was 2000 years ago! Today we know about water-borne illnesses and where they come from and how to treat them whereas back then the medical experts of the day attributed most illness to ‘bad air’ and tried solving most of the body’s maladies through the dubious practice of bloodletting. However, if we dig a little bit deeper we may find that, despite our improved knowledge about water sanitation, water and wastewater systems in Rome today might not be all they used to.

I will divide my comparison of Ancient versus Modern Roman water sanitation into three main parts. The first section will assess water sanitation of Ancient Rome, the second will assess that of Modern Rome, and the final section will summarize my findings and attempt to compare the two. In an effort to make my comparison as unbiased and empirical as possible, I will rely on two globally recognized metrics.

The first metric is the “JMP Service Ladder for Drinking Water, Sanitation, and Hygiene”. JMP stands for Joint Monitoring Programme for Water Supply, Sanitation, and Hygiene and is an organization run jointly by UNICEF and the World Health Organization. It was established in 1990 in order to provide “regular global reports on drinking-water and sanitation coverage” (WHO/UNICEF Joint Monitoring Programme for Water Supply). The JMP developed three different ‘ladders’ (shown below) which can be used to rate a society based on level of service for drinking water, sanitation, and hygiene.

Figure 1: Graphic of the three JMP Ladders taken from washdata.org

The second metric is the standard set in the July 2010 UN Assembly in regards to human rights to water and sanitation. The Assembly recognized the basic human right to have sufficient access to water which must be safe, affordable, and physically accessible (United Nations 2010). This is basically a yes-or-no metric based on three criteria defined by the UN Assembly.

  1. Sufficient water is defined as at least 50 liters of water per person per day for personal and domestic use
  2. Affordable water should constitute no more than 3 percent of household income
  3. Physically accessible water has to be within 1000 meters of the home and collection time should not exceed 30 minutes

Part 1: Ancient Rome

Figure 2: An example of all that remains today of Rome’s ancient aqueducts.

The term ‘Ancient Rome’ is hardly specific. Colloquially it is typically used to refer to Rome from its founding in the 8th century BC to the fall of the Roman Empire in 476 AD. For the sake of this study I have chosen to consider the city of Rome (as opposed to the entire Roman Empire) at its height of around 1.5 million citizens circa 100 AD. The reason for this is because that was the only time before the modern era that Rome had a population on the same order as its present day standing of 2.9 million citizens.

JMP Standards

Drinking Water

The JMP Drinking Water Ladder criteria assesses water quality based on its source and the time it takes to collect water. By the year 100 AD Rome got almost all of its water from nine aqueducts (Hansen). The quality of water coming in from these aqueducts varied greatly, depending on the source. Only the cleanest water was diverted to drinking water sources, while the rest served other uses such as fountains, baths, and gardens. While the ancient Romans did not have access to the technology which would allow them to filter bacteria from their drinking water, they did utilize several other technologies in an attempt to make their drinking water as clean as possible. Settling basins were built near the source and/or outlet of aqueducts so that larger debris and particulates could be filtered from the water. In addition, sections of the aqueducts which were exposed above ground were typically covered to prevent contamination from dirt, leaves, animals, and to protect it from the heat of the sun (Hansen).

The following image of the Aqua Felice shows an example of an aqueduct with a cover to prevent water contamination. This aqueduct was actually not constructed until the late 16th century, but it features the same kind of covered top that would have been used in the ancient aqueducts.

Figure 3: The Aqua Felice as seen at Parco deli Acquedotti.

The use of covered aqueducts therefore technically qualifies as an ‘improved drinking water source’. Since no chemicals were used to treat the water this label is not a perfect fit by today’s standards, but it is the most correct based on the definition given in the JMP ladder system.

Now the only question is availability. Most ancient Romans were not wealthy enough to afford to have water pumped directly into their homes, so this excludes the ‘Safely Managed’ category. The last two remaining categories are ‘Limited or ‘Basic’ and depends on whether or not it would typically take more than 30 minutes including queue time to collect water. This question can only be answered speculatively, but hopefully we can come up with a reasonable answer.

Let’s start with the fact that by 98 AD, the Water Commissioner of Rome, Sextus Julius Frontinus had counted a total of 591 public basins around Rome (Frontinus and Herschel 1973). Next we’ll need to estimate the physical size of the city of Rome circa 100 AD. The Aurelian Walls, which weren’t completed until 275 AD, encompassed an area of roughly 5.3 square miles (Aurelian Walls). Using them as a rough estimate for the physical size of Rome around 100 AD is reasonable since the Aurelian Walls encompass all seven of Rome’s famous hills. Also, since Rome’s population began to decline shortly after 100 AD, it is reasonable to assume that the physical size of Rome was roughly the same, if not slightly larger, than what it was in 275 AD.  

If we make the assumption that all 591 public basins were evenly distributed in 5.3 square miles, that all 1.5 million citizens lived inside the walls, and that the walls encompassed a roughly square area, we can calculate the average maximum distance a Roman needed to walk to collect water to be 506 feet. Assuming an average walking speed of 2 miles per hour and assuming water collection takes no more than 5 minutes (including queuing time), we come to a very rough estimate of 12 minutes.

This estimate is full of tenuous assumptions. It is highly unlikely that all 591 public basins were evenly distributed around Rome and it was certainly not the case that all 1.5 million citizens lived evenly distributed or even entirely within the Aurelian Walls. It is more likely that the majority of people lived in condensed clumps, but seeing as these clumps would almost certainly have been located around water sources, I think it is still reasonable to conclude that the average Roman most likely did not have to spend more than 30 minutes collecting water. This places Ancient Rome under the ‘Basic’ classification for drinking water.

Before moving on it is also important to note that the Ancient Romans commonly used lead pipes for the distribution of water once it was directed away from the main aqueduct. Today we are aware of a myriad of health consequences associated with lead poisoning and some historians have even suggested that the collapse of Rome itself was due to wide-spread lead poisoning of the aristocracy. This theory has long since been debunked. In the book “Roman Aqueducts and Water Supply”, historian A. Trevor Hodge describes how naturally high concentrations of hard minerals such as calcium would get deposited in the lead pipes and effectively act as insulation (Hodge 1992). There is also little to no evidence of lead poisoning from the analysis of ancient roman human remains.

Figure 4: Two thousand year old lead pipes uncovered at Ostia Antica; the port city of Ancient Rome.

Sanitation

The JMP standards for sanitation are a bit more straightforward and deal solely with wastewater management. Ancient Rome had an abundance of public baths and toilets which were fed by a (theoretically) constant stream of water which served to flush out urine and fecal matter. Since only the wealthiest could afford private bathrooms located inside one’s house, the vast majority of ancient Romans used shared facilities (Hansen). This places ancient Rome squarely on the ‘Limited’ bracket in terms of the JMP Sanitation Ladder.

Figure 5: A rare example of a private toilet located underneath the stairwell of a once-lavish home in Ostia Antica.
Figures 6-9: Examples of three different styles of drains. Ancient Roman drains combined wastewater from public toilets with cleaner surface water runoff and outflow from fountains.

Hygiene

This category is also relatively cut-and-dry as it deals only with handwashing practices. While there is a preponderance of evidence showing that most public restrooms of that period had (or at least were designed to have) flowing water to rinse ones’ hands, it is difficult to know exactly how common handwashing with soap was at that time. While the use of scented oils for bathing was certainly widespread by this point, oils do not have the same hygienic properties as soap and there is little evidence that suggests they were used at toilets. We can be fairly confident that Romans were using soap in general by the first century AD thanks to the Natural History, a book written by Pliny the Elder who was a Roman naval commander (The History of Soapmaking).

In his book, Pliny the Elder describes a recipe for making soap and outlines its primary use as a way to “to disperse scrofulous sores” (The History of Soapmaking). This suggests that soap was probably not used habitually after toilet use nor would it have been available for common use the way we are accustomed to seeing it today. Instead, soap probably functioned more as a medical treatment for disinfecting wounds and sores. By observing the exact wording of the JMP Handwashing Ladder, the most reasonable category for Rome at this time is ‘Limited’ since public restrooms likely had flowing water, but not soap.

UN Standards

Amount of Water

By the year 100 AD nine out of the eventual eleven of Rome’s famous aqueducts had already been built. The figure below is taken from Peter Aicher’s book “Guide to the Aqueducts of Ancient Rome”, and has estimated flow rates for each of them.

Figure 10: Estimated flow rates and water quality for each of Ancient Rome’s eleven aqueducts (Aicher 1995).
Figure 11: Map of Rome’s nine aqueducts at the time of Frontinus (Hansen).

By summing the flow rates of the nine completed aqueducts we find that Rome in 100 AD was supplied with at most 412 ft3/s of water or about 222 million gallons of water per day. Divided evenly between 1.5 million inhabitants would give about 148 gal/per/day or 673 liter/per/day.

When compared to the UN standard of 50 liter/per/day this number seems phenomenal. However, there is evidence which suggests that the real number is likely far lower than this. The aqueducts frequently operated well below their maximum flow rate due to sedimentation build up in the channels. In addition, there were extended periods of time where aqueducts would not be running at all typically due to closures for repairs (Hansen). Also, a frequent problem with the aqueducts was something known as “puncturing”, where farmers would illegally tap into the aqueducts and steal some of its flow to use on their crops. The most important factor though was probably the fact that this water was certainly not distributed evenly amongst all 1.5 million people of Rome. In one estimate by Sextus Julius Frontinus, a well known Roman Civil Engineer of the 1st century AD, only 44 percent of the water brought in via the aqueducts was diverted for public consumption (Hansen).  

By taking these factors into account it is unlikely that more than 10% of the max theoretical water flow from the aqueducts reached an average citizen. Thus, a more conservative estimate for the amount of water available to the average inhabitant of ancient Rome would be something on the order of 60-70 liters/per/day. This number also agrees amazingly well with the per capita estimate of 67 liters/day made by historian Christer Bruun in his 1991 paper titled “The Water Supply of Rome: A Study of Roman Imperial Administration”.  

Cost of Water

Thanks to Rome’s 591 public water fountains running non-stop, Ancient Romans enjoyed a privilege that many people in modern times still do not have access too – free drinking water. Of course, as with anything in life you cannot get something for nothing. These public fountains did not build themselves. They were built using funds collected via a remarkably well-organized and well-regulated taxation system which Rome had been developing for centuries (Boek 2008).

The specific ways and amounts of taxes which Rome collected varied greatly depending on when and where you are talking about. For the most part, the Roman Empire collected the majority of its tax revenue from land tax, but there were also taxes on trade, marriage, inheritance, and even urine (Emperor Nero of the first century AD famously initiated this widely unpopular tax which was eventually rescinded, only to be reenacted by his successor Vespasian to help dig Rome out of debt).

While the Ancient Romans certainly had to pay their share of taxes, since most taxes came from land (which it was not likely for city dwellers to own) and anyone could use the fountains regardless of how much taxes they paid, Ancient Rome still meets the UN qualification that water cost no more than 3% of household income.     

Physical Accessibility

This criteria has quite a bit of overlap with the JMP Drinking Water ladder criteria. As such, most of the analysis regarding this topic has already been discussed. It is reasonable to assume that for most inhabitants of the city of Ancient Rome there would have been a water source within 1000 meters, and it likely would not have taken more than 30 minutes to collect water.

Part 2: Modern Rome

Figure 12: Villa d’Este, a 16th century villa in Trivoli near Rome which features impressive and (relatively) modern water features.

JMP Standards

Drinking Water

Do present day Romans have access to drinking water which is ‘from an improved water source which is located on premises, available when needed, and free from faecal and priority chemical contamination’? A report published in the late 1990’s states that 86% of Rome’s drinking water comes from karstic springs (Bono and Boni 1996). In an article published by TAPP Water in 2017 that number had risen to 97% (Can I Drink the Tap Water in Rome?). This satisfies the drinking water being from an ‘improved source’.

In ISTAT’s 2019 Water Report, about 10% of Italians reported complaints about irregular water supply to their house (ISTAT 2019 Water Report). The majority of these cases are likely in more rural and remote areas, which means that the percentage of modern-day Romans who suffer from irregular water supply to their homes is almost certainly less than 10%. This qualifies Modern Rome as having drinking water ‘available when needed’.

ACEA is the company responsible for supplying Rome with tap water in addition to managing many of Rome’s historic water fountains. The water is treated with chlorine and generally considered to be of high quality (Can I Drink the Tap Water in Rome?). Present day Rome meets the criteria for the highest JMP Drinking Water standard, ‘Safely Managed’.   

Figure 13: Trevi Fountain; one of the nine historic fountains managed by ACEA.

Sanitation

Practically all modern-day homes and apartments in Rome come equipped with their own bathrooms. However, in order to meet the highest standard these facilities must either safely dispose of the ‘excreta’ or move it somewhere off-site where it is treated. ACEA is also the entity responsible for the management of wastewater in Rome. According to Tom Rankin, an architect who has lived in Rome for over 30 years, wastewater is dumped into the Tiber river is only treated to about 50%.

This low level of wastewater treatment results in severe pollution of the Tiber River and is not compliant with current EU standards. Therefore, Modern Rome does not receive a ‘Safely Managed’ sanitation ranking.

Figure 14: A modern-day Roman personal waste management system. Despite its criminally low flow rate, this technology still successfully manages to transport waste off-site.

Hygiene

As shown in the image below, bathroom sinks are the standard for Modern Roman apartments. While the soap is not provided for free, it is readily available for a small price at countless stores in Rome. This qualifies Modern Rome for the highest JMP sanitation standard, ‘Basic’.

Figure 15: The Author’s personal hygiene station, complete with flowing water and soap.

UN Standards

Amount of Water

According to ISTAT, the Italian National Institute of Statistics, in 2015 the average daily water supply to all Italians was roughly 220 liters per day per person. It is reasonable to assume this number is on par if not slightly lower than the per capita daily water supply to modern day Romans since the national average includes many rural regions with much more limited access to water than Rome. This places modern day Rome well above the UN minimum standard of 50 liter/per/day (ISTAT 2019 Water Report).

Cost of Water

In their March 2019 report on Italian water statistics, ISTAT reported that in 2016 the average monthly expense for water services to dwellings for all of Italy was roughly 14 euros (ISTAT 2019 Water Report). This constitutes less than one percent of Italy’s average annual household income for 2016 (30,595 euros according to the same institution). Average income and water service prices certainly vary from city to city in Italy, however based on the national averages it is safe to assume that modern day Romans also pay well below the 3% cost threshold set by the UN.

Physical Accessibility

As previously discussed, apartments and houses in Rome have access to tap water which means they also meet the UN’s standard for physical accessibility of water.

Part 3: Summary

According to the above analysis, Modern Rome outperforms Ancient Rome in all three JMP categories, while both societies successfully met all three UN criteria for the human right to water.

The advantage of using the JMP system is that it can give a more detailed description on the quality of water and hygiene services available to a society. This is more informative than the stark “yes-no” outcomes of the UN system which do not give any sense of how close a society is to meeting that threshold or not. The UN system is useful though because it highlights the fact that even though a society may not have abundant water resources, it still has enough to be sufficient for a basic quality of life.

It is interesting to note that relying only on the UN Human Rights criteria would lead us to conclude that both societies score equally, whereas if we were to only consider the JMP Ladder criteria we would conclude that modern Rome decidedly outperforms ancient Rome. This can be seen by reviewing the table below.

Figure 16: Summary of how each society compares based on the three JMP Ladders and the UN Human Rights criteria.

In the end modern Rome can still safely say that it has improved its water sanitation services over the past 2000 years, but perhaps by a narrower margin than one would expect given the rapid technological developments of the past two millennia. While ancient Rome did not score perfectly in every category, at least according to the JMP system, it is worth noting that they would still outperform other modern day cities in poorer parts of the world today.

References

Aicher, Peter J. Guide to the Aqueducts of Ancient Rome. Bolchazy-Carducci, 1995.

“Aurelian Walls.” Military Wiki, military.wikia.org/wiki/Aurelian_Walls.

Boek, Johannes Alexander. “Taxation in the Later Roman Empire.” Leiden Repository, 28 Jan. 2008, openaccess.leidenuniv.nl/bitstream/handle/1887/18524/Taxation_in_the_later_Roman_Emp.pdf?sequence=1.

Bono, P., and Boni, C. “Water Supply of Rome in Antiquity and Today.” Environmental Geology, vol. 27, no. 2, 1996, pp. 126–134., doi:10.1007/s002540050043.

Bruun, Christer. The Water Supply of Ancient Rome: A Study of Roman Imperial Administration. (Commentationes Humanarum Litterarum, number 93.) Helsinki: Societas Scientiarum Fennica. 1991. Pp. viii, 456, The American Historical Review, Volume 98, Issue 2, April 1993, Page 479, https://doi.org/10.1086/ahr/98.2.479

“Can I Drink the Tap Water in Rome? – TAPP Water.” EN, 10 June 2019, tappwater.co/en/can-i-drink-tap-water-in-rome/.

“From Luxury to Necessity​ – A History of Soap.” From Luxury to Necessity-A History of Soap – Watchtower ONLINE LIBRARY, 2005, wol.jw.org/en/wol/d/r1/lp-e/102005564#h=6.

Frontinus, Sextus Julius, and Herschel, Clemens. The Two Books on the Water Supply of the City of Rome of Sextus Julius Frontinus, Water Commissioner of the City of Rome, A.D. 97. New England Water Works Association, 1973.

Hansen, Roger D. “WATER AND WASTEWATER SYSTEMS IN IMPERIAL ROME.” WaterHistory.org, waterhistory.org/histories/rome/.

Hodge, Alfred Trevor. Roman Aqueducts & Water Supply. Duckworth, 1992.

“ISTAT 2019 Water Report.” Istat.it, 22 Mar. 2019, www.istat.it/it/files/2019/03/Water-report.pdf.

“The History of Soapmaking.” OpenLearn, The Open University, 27 Sept. 2007, www.open.edu/openlearn/history-the-arts/history/history-science-technology-and-medicine/history-science/the-history-soapmaking.

“Water.” United Nations, United Nations, www.un.org/en/sections/issues-depth/water/.

“WHO/UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene (JMP): UN_Water.” UN, www.unwater.org/publication_categories/whounicef-joint-monitoring-programme-for-water-supply-sanitation-hygiene-jmp/.

“World Water Day.” Istat.it, 22 Mar. 2018, www.istat.it/en/files/2018/03/EN_Focus-acque-2018.pdf?title=Istat+water+statistics+-+22+Mar+2018+-+Full+text+and+methodological+note.pdf.

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