Digging wells: Wells and the association Archéologie des Puits (ADP)

Sacha Ranchin & Louis Lacoste
Archéologie des Puits

The “Archéologie des Puits” (ADP) association was founded in 2021 with the aim of offering safe archaeological excavation of wells based on the use of a specific technical equipment. The association is located in Aspiran, in the Hérault Valley, southern France. Its founding members are professional archaeologists with diverse skill sets and field experience including the exploration of numerous wells. Some of our members used to be a part of the French association known as “Archéopuits” which pioneered the methodology of well exploration by platform. See Figure 21.

Figure 21. ADP’s platform equipped and ready for the dig. Image courtesy of Archéologie des Puits.

Archaeological interest in wells

Wells are structures which are omnipresent in archaeology from the Neolithic to the Modern era. Before the popularization of the distribution of water through a pressured pipe system, they constituted most people’s main reliable access to water.

On archaeological sites, which are often leveled in rural contexts by agricultural activities, or perturbed by the stratigraphy of following occupations in urban contexts, wells provide a stratigraphy of their use and subsequent filling which can span from a few meters to tens of meters. These stratigraphic layers bring up information that is often completely absent from archaeological levels at the surface. The contexts represented by wells are subject to very few alterations and thus allow for an excellent conservation potential of artefacts. Therefore, the study of wells allows us to explore the stratigraphy of their use from the original digging of a structure to its eventual abandonment.

Furthermore, wells are great for trapping pollen, insects and seeds. Studying wells and their contents thus allows us to rejuvenate our approach of ancient environments with paleo-environmental studies made possible by the outstanding conservation state of organic matter in these contexts. As a consequence, we are able to better understand the evolution of an ancient environment in relation to any explored well currently under study. The specific context of wells also favors the conservation of wood and wooden material. In addition, they also provide information regarding unknown religious and cultural activities and practices by the discovery of votive objects and other organized caches. Additionally, study of the construction of the well-shaft of these structures also brings us information about well construction and maintenance over time.

Well exploration usually takes place in the final stages of archaeological field work. The data that is gathered in these structures demands the intervention of a number of specialists and represents a truly multidisciplinary endeavor. Nonetheless, the amount of data to be gathered in these structures justifies the effort and the expenses put into their exploration. See Figure 22.

Figure 22. Some archaeological material found in a well. Image courtesy of Archéologie des Puits.

A brief history of the exploration of wells

Even if the scientific potential of these structures is acknowledged, their exploration often remained an incomplete process, dictated by time pressures and in dangerous conditions. In France, the archaeological exploration of wells began during the 19th century, but was only truly developed over the last 30 years through upgrades in the operating conditions and through the acquisition of innovative and exciting scientific results from conservation of organic matter whose outstanding state of preservation is linked to wells’ dark, humid, and low oxygen contexts. These improvements were made through the realization of the inherent risks attached to this kind of archaeological explorations and the establishment of a strict methodology.

The dangers of well exploration

Well explorations expose archaeologists to a number of potential risks of which they have to be both aware and are equipped to avoid. Firstly, before, during and after the exploration process, there is always a risk of people falling into the structure. During the excavation process, the most vulnerable individual is the person at the bottom of the structure who faces multiple kinds of danger. The technician is the first affected by falling tools, rocks, pebbles and other objects. As the shaft of wells can potentially be quite deep, there is a risk of collapse. This is often compounded by the well-shaft having not been in structural tension for some time as any potential fill is removed. There is also a risk of dangerous gaseous emanations which can potentially be lethal at certain depths. (ADP was confronted by this situation during the exploration of a structure in Martigues, in Bouches-du-Rhône, France). Furthermore, the digger at the bottom of the structure is faced with the potential dangers of floods and the associated risk of drowning. The technician is also exposed to microbial contamination from to the stagnant water contained in these structures. The equipment on the surface presents further technical and electrical dangers. Even after the completion of the exploration process, wells remain potential sources of danger; it is, thus, advisable to refill the structures entirely.

These various safety risks highlight the need for the establishment of a strict operational methodology, which grants the scientific community access to the wealth of scientific knowledge contained in these structures all the while lowering potential risks to a minimum.

The methodology of well exploration

The technical stakes which precede the archaeological exploration of wells are intended to minimize danger and to ensure the safety of everyone involved. To that end, the installation of an independent mobile platform above the shaft of the structure is fundamental. This platform is built from steel beams which are used as a support for a winch cage. Made from construction grade material, this above ground structure constitutes a mobile and adaptable ensemble capable of supporting high charges, and capable of being set in place in any type of context. A floor is then installed on the structure to create a workspace. The winch cage is fixed above the shaft and is equipped with two winches to bring the technician and the content of the structure up and down the well safely. The equipment set up in the cage includes an electrical winch, a mechanical winch, the anti-fall device, a life line and an electrical counter connected to an independent generator. The lights, the ventilation and the pumps are plugged into the counter. A skirt is installed around the opening to the shaft as a measure to prevent tools and other objects from falling down the shaft. A set of railing is installed to avoid the fall of persons. The platform is also equipped with an extinguisher and a first aid kit, and its potential dangers are indicated through the use of easily readable danger signs.

Our team generally does an initial assessment to determine the safety levels and the technical requirements needed for the exploration of a particular structure before setting the platform up. Consequently, we are able to take into account the problems posed by the evacuation of water and debris. Once this technical challenge has been met, our team follows strict protocols to facilitate the exploration process, which can last up to a week.

Before lowering any personal in the structure, it is crucial to proceed with the execution of a gas test in order to identify any potential traces of methane, carbon monoxide, carbon dioxide, sulfured hydrogen and to measure the amount of oxygen present. Filling out and signing off on a comprehensive checklist is required before each descent. During the underground operations, the licensed technician is also required to check the walls of the shaft to assess their status and determine any potential need for consolidation. If any doubts are raised during this process, the operation can be suspended until the specific problems are solved in order to guarantee the safety of the technician.

During the operation, the work is focused on two individuals; the technician at the bottom of the well, and the winch operator who communicates with the technician and raises debris and artefacts according to the principles of working with heights. Every individual on the platform is required to be equipped with a secured hard hat, a harness, gloves, and an anti-fall device to ensure their safety at all times. Outside of the operations on the platform, well exploration requires the use of several other technicians to evacuate and sift through sediments, to take samples, and treat artefacts, etc. See Figure 23.

Figure 23. The technician digging a dry well. Image courtesy of Archéologie des Puits.

The Archéologie des Puits association

Archéologie des Puits (ADP) was founded to meet those technical and scientific challenges, and to do so safely. Our first duty is to secure the well in order to grant us the ability to safely explore the structure. Our custom-made platform and its mobility allow us to work in any type of context, be it inside or outside, wet or dry.

Thanks to the great amount of expertise and experience held by the members of our association, we are able to explore well structures but to also conduct artefacts studies and we are capable of handling any type of samples and are experts in paleo-environmental sampling and studies. As of 2023, ADP has 20 members, all of whom are archaeologists, and whom are furthermore also trained and licensed for the exploration of confined spaces.

ADP is able to:

  • Stratigraphically explore wells in urban and rural contexts following a safe protocol (including the recording and description of each stratigraphic unit).
  • Proceed with the treatment of different artefacts (terracotta, ceramic, amphorae, glass, small finds, etc.) as they are being excavated from the structure (including washing, inventory, isolation and conditioning).
  • Take systematic paleo-environmental samples, sort these and follow through with subsequent studies.
  • Conduct artefact studies

ADP is equipped with an adaptable and metallic platform. The structure is mobile and secured and is equipped with every possible piece of gear needed to realize the full range of its operational capabilities. The aims of the association are the following:

  • To implement exploration as well as to promote, study and develop the archaeological exploration of wells.
  • To offer training sessions and internships for students of archaeology, with the goal of introducing them to the different specializations within archaeology.
  • To organize cultural and scientific communications relative to the archaeological exploration of wells.
  • Execute archaeological operations, artefact inventories and well studies for a variety of actors in the field of archaeology (Europe and north Africa).
  • Promote scientific and methodological exchanges between specialists of different subjects within archaeology around the Mediterranean and in Europe.

Persons interested in working further with Archéologie des Puits are welcome to contact us via our website: https://archeologiedespuits.fr

Bibliography and further resources

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