The coal mines and saltworks of Gouhenans constitute a complex of mines and factories situated in eastern France. They have been engaged in the exploitation and processing of rock salt and pyrite since 1831 and coal since 1828. These resources are situated in the same geological layer of the Keuper Basin. The coal deposit was first identified in the 1770s and is situated beneath the communes of Gouhenans, Athesans, and Villafans in the Haute-Saône department, in Bourgogne-Franche-Comté. The discovery of salt occurred concurrently with the onset of coal mining operations. The use of locally mined coal for the evaporation of brine enabled the company to reduce the cost of production of salt. The industrial complex was further expanded with the addition of a chemical factory and glassworks, which contributed to a period of economic growth and prosperity in Gouhenans. In 1927, the Kuhlmann group acquired the chemical activity, which remained under their ownership until the facility's closure in 1955.
In 1847, the salt industry was embroiled in a scandal involving prominent political figures of the July Monarchy, General Despans-Cubières, and Jean-Baptiste Teste, a peer of France and Minister of State.
The vestiges of these industrial activities (mine entrances, spoil heaps, railways, ruins, company town, repurposed buildings, flue-gas stack, and lindane deposits) persist in the early 21st century. The region continues to be shaped economically, socially, scenically, ecologically, and culturally. In 2009, the hiking trail "The Way of Salt and Coal" was established to draw attention to this industrial heritage.
Location The concession encompasses 1,378 hectares for coal exploitation and 688 hectares for salt, distributed across the communes of Gouhenans, Longevelle, Les Aynans, Athesans, Le Val, and Villafans, situated in the southeastern region of the Haute-Saône department within the Bourgogne-Franche-Comté region.
Geology
The coal and halite deposits are intermingled within the Keuper coal basin of Haute-Saône. The basin is composed of alternating layers of sandstone, variegated marl, and gypsum dolomites.
The comprises six layers with a total thickness of 22 meters, found at depths between 51 and 107 meters.
Saltworks
Neolithic Archaeological evidence indicates that salt was extracted in the commune during the Neolithic era, with the earliest known instances of this practice occurring between 4821 and 4534 BC.
Discovery In 1828, during the exploitation of the coal deposit, a seven-to-eight-meter-thick layer of rock salt was discovered. The initial exploitation request was rejected, and despite subsequent appeals to the courts in Lure, Besançon, and the Council of State, the situation remained unchanged. Consequently, the saltworks were constructed illegally at the site known as Les Époisses. The factory employed the ignigenous process, using brine cooking in stoves. Ultimately, the royal ordinance of 3 January 1843, granted the Parmentier, Grillet and Co. company the concession for a rock salt mine. The brine was obtained by sending fresh water over the salt layers through boreholes. The water was then evaporated in 37 pans with a total surface area of 2,211 m². This technique allowed the deposit to be considered a salty source rather than a mine, thereby avoiding the state monopoly.
Teste-Cubières scandal
In July 1831, the concession company initiated its operations and established workshops for the evaporation of salt. The treatment conditions, particularly the abundance of inexpensive [uel from the coal mines, enabled the sale of the salt at prices that were lower than those of the in the east. The incident provoked resentment and resulted in a scandal in 1847, involving General Despans-Cubières, who had previously served as and was seeking election as a . He was the proprietor of 159,000 shares in the company, representing 7% of the capital. The Minister of Public Works, Jean-Baptiste Teste, was also implicated in the incident, having received a bribe of 94,000 francs in exchange for granting the concession.
The scandal was subsequently amplified and exploited by both left-wing and right-wing opposition groups to discredit the July Monarchy. In his collection, , Victor Hugo provides a detailed account of the corruption trial that took place before the Court of Peers. Ultimately, General Despans-Cubières and the concessionaire, Mr. Parmentier, were sentenced to and a of 10,000 francs. The fine imposed on Jean-Baptiste Teste amounted to 94,000 francs, and he was also sentenced to three years' imprisonment, notably being confined to the Conciergerie until the 1848 Revolution. The banquet campaign ultimately resulted in the fall of Louis-Philippe six months later. Meanwhile, the Gouhenan's saltworks continued to flourish.
Development
On 28 March 1843, an ordinance was enacted that authorized the activation and expansion of the saltworks, which was subsequently relocated to its final location to the east of the village. By 1866, the old site was no longer in use and had been repurposed as housing for workers. The facility's output reached 10,000 tons per year between 1845 and 1856, with operations conducted continuously, including on Sundays and holidays. In 1844, authorization was granted for the construction of a "reverberatory furnace soda factory, soda salt, tartaric acid, hydrochloric acid, sodium sulfate, tin salt, and gelatin extracted from bones by hydrochloric acid." The chemical factory in question was constructed around 1848. In approximately 1850, the complex was acquired by the due to the competitive nature of its operations. In 1864, the production of salt reached 102,000 quintals. By 1869, the pans had reached a size of sixteen by seven meters, with an output of nearly four tons of salt per day. The production of 100 kilograms of salt required the consumption of 65 kilograms of coal. The chemical factory produced sulfuric acid, hydrochloric acid, nitric acid, sodium sulfate, and calcium chloride.
In the 1890s the factory in question was responsible for the production of 40,000 quintals of hydrochloric acid, sulfuric acid, and sodium sulfate on an annual basis. The factory was subsequently owned by the Compagnie Anonyme des Salines, Houillères et Fabrique de Produits Chimiques de Gouhenans. In 1895, the construction of three 100-meter-deep boreholes enabled the production of 61,550 quintals of salt. In the subsequent year, the establishment of a railway branch with the inauguration of the , situated near the complex, facilitated the transportation of goods and personnel. In 1905, a glassworks was constructed to the north of the site, which had been built in 1903, and employed between thirty and forty workers. The factory's primary product was beer bottles for breweries in Alsace. However, it experienced several periods of interruption, ultimately closing permanently following the conclusion of World War I. The facility's large chimney was used for the venting of gases produced during the manufacturing of sodium sulfate and sulfuric acid. Additionally, the facility expelled the smoke from steam boilers that powered electrical generators. Upon the establishment of an electrical grid in the village of Gouhenans, the factory's generators were connected and provided supplementary power. In 1916, the upper 50-meter portion of the large chimney, which had undergone a tilting movement, was straightened by specialized workers. In 1927, the site was divided between two companies: the Société Minière et Industrielle de Gouhenans and the , which employed a total of 70 individuals by 1931. Despite the addition of nine pans in 1926, the production of salt exhibited a gradual decline from 8,249 tons in 1912 to 7,200 tons in 1943. This decline was attributable to the increased costs of transporting coal, coupled with a lack of profitability and investment, which resulted in a loss of competitiveness against salt marshes.
Conversion The saltworks ceased operations shortly after the conclusion of World War II, followed by the Kuhlmann factory in 1955. Some of the buildings were subsequently repurposed as warehouses for chemical products, but the majority were demolished in the 1970s. One of the two pavilions situated at the west entrance was destroyed by fire in 1992.
Lindane deposit In 1974, 5,200 tons of lindane (a pesticide that was subsequently withdrawn from the market due to its inherent dangers) belonging to the were illegally dumped in a location north of the site in question. Even though the responsibility for treating these wastes was assigned to the Socrimex company, they were instead covered with tarps and tires. In response, an opposition committee was established, and a petition was circulated, ultimately garnering 30,000 signatures. In an order dated 6 August 1974, the Haute-Saône prefecture requested the removal of the products by 26 February 1975, for treatment at the Loos-lès-Lille factory. However, no action was taken. After the pollution of a tributary of the Ognon, the Socrimex company was placed into liquidation, and its manager was fined 300 francs by the Lure court in June 1975. However, the manager was subsequently acquitted in April 1976.
The waste was ultimately interred in 1980 in five pits excavated to a depth of ten to fifteen meters into the marl and sealed with ash. In July 1983, the BRGM published a study indicating that lindane was leaking at a rate of 120 grams per year. However, the pollution exhibited a gradual decrease throughout the subsequent decade.
In December 1989, the BRGM observed an increase in pollution in the vicinity of the site, leading to the conclusion that the deposit was not watertight. Subsequently, the deposit was covered with an anti-punching geotextile, an HDPE geomembrane, a 10 cm layer of sand, an anti-contaminant geotextile, a 0.8 to 1-meter layer of marl, and a top layer of turf. The entire structure was encased in a concrete foundation with a depth of 50 centimeters. However, no insulation was provided for the base of the pits. These works were carried out by the Bachy company in the early 1990s. Monitoring was conducted every six months. Groundwater pollution was detected in 1998, and piezometers were installed in 2000 to improve monitoring. No external pollution was detected throughout the following decade until another increase in lindane levels was observed in June 2010, before returning to normal levels in the subsequent months and years.
Heritage At the beginning of the 21st century, the site was extensively overgrown with vegetation. Only a few remnants of the former buildings remain, some in ruins and others repurposed. The sole remaining tall square chimney stands as a testament to the site's industrial past. In 2003, the initiated a study of a hiking trail project to showcase the region's industrial heritage, particularly its saltworks and coal mines. The route, titled "The Way of Salt and Coal", is funded 25% by the and 40% by the European Union. It was inaugurated on 25 June 2009, by the sub-prefect and a hundred people. Subsequently, on 11 March 2010, the saltworks were registered in the general inventory of cultural heritage.
Coal mines
Former operations The coal deposit was initially identified in the vicinity of the village of Gouhenans during the 18th century. In November 1776, the intendant of Franche-Comté and Minister Henri Bertin initiated a correspondence to authorize the exploitation of the Gouhenan's coal. However, the mining operations ultimately ceased in April 1780 due to the prevalence of water infiltration.Pierre Semonin based on the Haute-Saône departmental archives and the archives of the Besançon municipal library.