Authorities have ordered the immediate suspension of operations at a Chinese-owned Semcorp in Debrecen after tests revealed aluminium levels in groundwater exceeding legal limits by more than 13,000 times.
The Hajdú-Bihar County Government Office took action against Semcorp Hungary Kft., which manufactures lithium-ion battery separator films, following an investigation that uncovered severe subsurface contamination. The findings also detected a range of other heavy metals, while the mayor of Debrecen has announced a criminal complaint in the case.
The company had previously maintained that a leaking, pungent, unidentified substance was merely condensation water and posed no environmental risk.
Chinese company insisted substance was harmless
The investigation began after samples were taken in February from a rainwater drainage channel near the industrial site, following an operational incident. During an on-site inspection on 26 February, officials recorded that a steaming, sharp-smelling, unidentified substance was seeping into the soil.
Despite this, the company claimed the leak consisted solely of condensate and contained no harmful pollutants. The authorities nevertheless ordered sampling — a decision that has since proved justified.
Laboratory results revealed unexpectedly severe contamination. Aluminium concentrations in groundwater reached 2,676,000 micrograms per litre, compared with a legal threshold of 200 micrograms per litre — more than 13,000 times the permitted level, local Debreciner wrote.
In addition to aluminium, elevated levels of several metals were detected, including arsenic, zinc, lead, cobalt, cadmium, nickel, barium, chromium, copper, manganese, lithium and iron. According to the authorities, most of these are not of natural origin, a conclusion supported by baseline environmental data from 2021.
Plant would have continued operating despite breach
Documents now in the public domain show that the authorities had already established a regulatory breach on 22 May. The contamination was traced to a section of the plant where aqueous aluminium oxide solutions are used — an area the company had intended to keep in operation.
The immediate suspension was deemed necessary, as further environmental damage could not be ruled out even during the appeals process.
The government office also noted that although Semcorp carried out mandatory sampling, it submitted the results after the deadline, resulting in a fine of one million forints. The company has challenged this penalty in court.
Multiple regulatory proceedings are now under way. Environmental authorities have ordered remediation measures, required a full site investigation, and launched proceedings over operations deviating from permit conditions. The company must also install waterproofing in a stormwater retention basin, conduct quarterly monitoring of observation wells, expand the scope of tested substances, and reimburse procedural costs exceeding two million forints.
Mayor files criminal complaint
László Papp, the mayor of Debrecen, said the city and its asset management company had been informed of groundwater contamination exceeding legal limits, which he described as unacceptable.
He stressed that this was not the first instance in which environmental concerns had arisen in connection with the company, and confirmed that the municipality had filed a criminal complaint.
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At the same time, Debreceni Vízmű, the local water utility, sought to reassure residents that the contamination does not affect the city’s drinking water supply. Drinking water is sourced from wells 160 to 230 metres deep, located far from industrial sites and protected by multiple impermeable layers.
The utility emphasised that the water remains safe to consume and of appropriate quality, adding that remediation of the contamination is entirely the responsibility of Semcorp.
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State-backed investment under scrutiny
The Chinese-owned Semcorp Group announced in 2021 that it would invest 65 billion forints to build its first production facility outside China in Debrecen. The Hungarian state supported the project with a subsidy of 13 billion forints, highlighting its potential to strengthen Hungary’s position in the battery industry and create 440 jobs.
According to the latest available data, the company employs 566 people, although public records do not specify how many are foreign workers.
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