Stampriet aquifer: Payment halts analysis
Namibian uranium mining company Headspring Investments’ own water analyses have shown significantly elevated levels of radioactive contamination in the groundwater in several boreholes investigated near Leonardville in the Stampriet aquifer area.Headspring Investments took water samples from 249 boreholes between 2021 and 2023, which were analysed by the German laboratory Hydroisotop GmbH and submitted to Matcon Investment for independent evaluation. In some of the water samples, international limits for alpha and beta concentrations in groundwater were significantly exceeded.
Of the boreholes analysed, 42 (16.9%) were Headspring’s own hydrological boreholes and 207 (83.1%) were farm boreholes located in the area of Headspring’s Exclusive Prospecting Licences (EPLs). According to the results of Matcon’s review, the maximum alpha activity in the farm boreholes was 1,443 Bq (becquerel - a unit used to measure the radioactivity of a substance, specifically the rate of radioactive decay) per kilogram.
World Health Organisation (WHO) guidelines set a limit of 0.5 Bq/kg, with 28 of the farm boreholes (14%) exceeding this. The maximum beta activity in the farm boreholes was 1,880 Bq/kg. The WHO guideline sets a limit of 1.0 Bq/kg, with 63 of the farm boreholes (30%) exceeding this.
The review report was seen by Network Media Hub (NMH).
NMH was also provided with more recent laboratory results from November 2024.
Headspring Investments, owned by Uranium One, a subsidiary of the Russian Atomic Energy Agency Rosatom, wants to mine uranium in the Stampriet aquifer. The company is still in the exploration phase, which has been suspended since the Ministry of Agriculture, Fisheries, Water and Land Reform withdrew its permit due to breaches of conditions.
'Natural decay'
Aldo Hengari, director of operations for Headspring Investments, explained that the increased limits are due to the natural decay of the uranium ore in the groundwater. A release of radioactive radiation from the drilling activities is technically not possible during the exploration phase, he said.
The Ministry of Agriculture confirmed to NMH that they were notified of the values by Headspring and have commenced their own analysis of water samples to determine alpha and beta concentrations in the Stampriet aquifer. The water samples were taken in November 2024.
“The analysis of the water quality samples at the laboratory has been delayed due to procurement procedures that require advance payment by the laboratory. This is in breach of our country’s procurement laws which allow for payment on delivery. [However,] the matter is at an advanced stage of resolution,” ministerial spokesperson Simon Nghipandulwa said.
The laboratory that will conduct the analyses is the South African Nuclear Energy Corporation with the expectation that it will take two months. Once completed, the ministry will determine whether the concentrations pose a risk to groundwater quality and public health.
“Based on the evaluation, it will determine the necessary regulatory or technical steps, including further investigations or protective measures, to ensure the long-term safety of the Stampriet aquifer and its users,” Nghipandulwa said.
Radionuclides
According to the ministry, the elevated levels were likely due to the natural decay of radioactive materials naturally occurring in the water. Detlof von Oertzen, a physicist with special expertise in the field of radiation management and director of VO Consulting, also confirmed that the Stampriet aquifer contains minerals in which radionuclides occur.
As a result, some of the water from boreholes in the aquifer contains radioactive elements such as uranium, radium and others. “The use of such water therefore means that these radioactive elements are ingested, which also means that the radioactive decay in the body leads to an exposure dose,” Von Oertzen said.
“The dosage makes the poison, meaning that low consumption of water from boreholes with high radionuclide concentrations only rarely leads to harm, but that drinking water from boreholes with high radionuclide concentrations does pose significant health risks.”
“Although exploration activities by Headspring did not cause an increase in alpha and beta activity within the Auob aquifer itself, the ministry is concerned that some of Headsprings’ boreholes were improperly constructed, leading to the leakage of water from the higher-activity Auob aquifer into the overlying Kalahari aquifer,” Nghipandulwa said.
“This hydraulic compound has likely contributed to elevated radioactivity levels in the Kalahari aquifer water used by humans.”
The International Atomic Energy Agency (IAEA) responded cautiously to queries from NMH about the observed radiation levels. “For the IAEA to provide definitive answers, it would be necessary to conduct a dedicated study, including sampling and analysis of radionuclides,” IAEA spokesperson Sinéad Harvey told NMH.
'Scientifically reasonable'
“It is scientifically reasonable to consider that naturally elevated levels of radioactivity could have existed prior to any exploration-related activities. The presence of uranium ore in the geological formations would naturally support the hypothesis of elevated uranium concentrations in the groundwater,” she said.
According to her, exploration activities could theoretically allow such activities to contribute to localised increases in radioactive content in groundwater, even in the absence of full-scale mining.
Headspring's Hengari submitted a letter from Environmental Commissioner Timoteus Mufeti to NMH stating that a request has been made by the Namibian government to the International Atomic Energy Agency (IAEA) for an expert and independent assessment. The request includes the assessment of Headspring's drilling activities on the site and must be completed by September 2025.