In the late 19th century, the toilet was introduced as we know it today. Previously most of Amsterdam households possessed a toilet cubicle in the courtyard of their house. The earliest mention of such a sanitary facility in the city, a heymelichede (secret) dates back to 1377. From 1528 it was officially obliged to provide every house with a crapper. Traces of these crappers archaeologists find regularly.
The round or rectangular walled container of the cesspit that had an average size of 2×2 m and 2 m deep, often it had a dome on top with an opening for the chute, which came out in the outhouse. A cesspool was often used by a single household, but it also happened that a well was connected through several chutes of privies from different premises. In addition to the sanitary function, the well was used in order to throw away waste. So these cesspools may contain large amounts of household waste, ranging from kitchen waste to crockery.
There were strict urban regulations for maintaining cesspools by homeowners. These full wells had to be emptied among other things. For this night workers were deployed. These workmen took their name in the night hours when they had to do their work because of the smell and inconvenience. The easiest way to empty a septic tank was to dig out these items from the chute. More dramatic was when the dome had to be broken and a mason had to restore the well later. The city took strict supervision of emptying these wells. In 1621 for example, the presence of a sworn superintendent by the mayor was made mandatory, to ensure that everything went properly and to prevent that the contents of the wells ended on the streets or in the canal. In practice of course, no-one was taken with such rules, according to a strengthening of the rule in 1623 which stated that the night workers had to be certified in order to practice their profession.
Emptying a cesspool was a costly operation and was often done only when it really had to. It often happens that cesspools that are found at archaeological investigations are often stocked. The utensils and food scraps literally give us a glimpse into the kitchen and on the table of Amsterdam households. Septic tanks are unique archaeological receptacles full of information that call many different, sometimes personal, aspects of daily life in the past visible and alive. In the past 40 years, the archaeologists of the Amsterdam municipality have unearthed nearly 400 cesspools.
See a map with all the cesspools they’ve found here