In 2020, for example, the RIVM warned against the formation of chromium-6 through chemical reactions. But the North Sea Canal Area Environment Agency only checked for the first time this year for the presence of this hazardous substance, which was subsequently found in the groundwater. The supervisor confirms this after questions from de Volkskrant about the affair.
The Environment Agency recently announced that chromium-6 had been found in the groundwater of Tata Steel, at a depth of 5 meters. The regulator immediately announced further investigations to rule out the possibility that the poison had spread through the groundwater.
Because chromium-6 has never been checked before, it is unclear how long the poison has been there and where it comes from. The monitoring wells in which the substance was found were put in the ground 11 years ago ‘for the monitoring regime’ that Tata Steel must comply with, according to a spokesperson for the Environment Agency. ‘These monitoring wells are sampled annually for the components as agreed in the permit. Chromium is not part of the annual monitoring. This year we did monitor for chromium, including chromium-6.’
Steel slag
According to the regulator, there was never a reason to check for the presence of chromium-6. The fact that the presence of this toxic and carcinogenic substance was suddenly checked this year is due to a ‘sum of signals’, according to a spokesperson for the Environment Agency.
Inquiries show that the most important signal is an advice from the RIVM from 2020 about chromium-6. Even then there was discussion about the possible presence of this toxic substance. This arose after a research agency had found chromium-6 at Harsco, a company that processes residual products, so-called slag, on the Tata Steel site. Tata Steel and Harsco doubted that: they had never found chromium-6 themselves and according to scientific insights there would be no chromium-6 in slag.
But the RIVM stated in 2020 that chemical reactions were possible in which chromium-6 could be formed in the snails and that the necessary substances were present. ‘Based on these considerations, it is likely that chromium-6 is present, as the measurement results show. Although the theoretical explanation offered by Tata Steel is correct, chromium-6 can be formed under the conditions prevailing in slag heaps, especially on the outside of the slag heaps.’
Concerned local residents
Tata Steel’s steel slag is used, among other things, for road and hydraulic engineering, such as in viaducts and asphalt. The company writes about this: ‘Steel slag is not harmful to nature, if used properly.’
After the discovery of chromium-6 in 2020 at Harsco, the Environment Agency had a follow-up investigation carried out in which the toxic substance was not found. The regulator then concluded that ‘it is sufficiently plausible that no chromium-6 is present at Harsco’.
But the IJmondig foundation, set up by concerned local residents, was alarmed by the RIVM report stating that chromium-6 can be formed in mountains with snails. For example, Tata Steel has constructed an artificial dune with steel slag and permits have now been issued for another artificial dune. Because, according to the RIVM, chromium-6 may also be created, the IJmondig Foundation applied for an enforcement request last year.
The foundation quickly received an answer from the regulator. ‘In the short term, one of our supervisors will carry out an inspection of the existing artificial dune. Specific attention will be paid to the possible creation, distribution and deposition of chromium III and VI.’ A year later, the investigation into the artificial dune has not yet been completed. But the foundation’s request did lead to broader research and thus the discovery of chromium-6 in the groundwater.
Drinking water
According to toxicologist Paul Scheepers of Radboudumc, the contamination with chromium-6 is manageable if it remains in the same place. But according to him there is a danger ‘that the contamination will move to an area where water is extracted for, for example, drinking water preparation’. ‘Furthermore, the contamination could eventually end up in the surface water.’
The village council of neighboring Wijk aan Zee has asked the province of North Holland to intervene as soon as possible and to examine the groundwater and soil in many more places for the presence of toxic substances.
A spokesperson for water company PWN, which extracts water in the dunes of North Holland, says that there is as yet no reason to take action ‘with regard to drinking water’. The nearest water extraction areas are about 1.5 kilometers from Tata Steel, according to the spokesperson. ‘Premise: chromium-6 should not be present in groundwater, but the groundwater flow is not directed towards our extraction sites.’
Supervisor the Environment Agency has now asked Tata Steel itself to investigate the nature and extent of the chromium-6 pollution. The steelmaker says they want to carry it out “with great diligence and care” in order to clarify the “cause, extent, consequences”.
Chromium-6 is a dangerous substance that, after exposure, can lead to serious health damage, such as cancer or infertility. Chromium is a metal found in the air and soil.
Not every form of chromium is harmful, but the non-harmful forms can be converted into the toxic chromium-6 through chemical processes, among other things. Chromium-6 prevents rust and rot and was therefore used in paint in the past. That has been banned since the 1990s.
In 2018, Defense personnel were found to have been exposed to chromium-6 on a large scale, while the ministry had known it was harmful since the 1970s.