Comments on Little and Jackson
Haszeldine, R Stuart
The potential impacts of CO2 on freshwater aquifers outlined by Little and Jackson, 2010 appear, incorrectly, to slay all hope of storing CO2 below ground and retaining safe drinking waters. Without doubt the effects of CO2 addition to drinking water aquifers deserve careful investigation. However, the experiments preformed by Little and Jackson are fatally flawed and there are a number of misleading and incorrect statements in the text. The authors collected sediment samples from aquifers which were already high in undesirable trace metals and elements, so much so that the natural groundwater measured in three of the four exceeds the EPA recommended concentration limit for Manganese and two exceed the limit for Iron, Aluminium, Selenium, Arsenic and Cadmium. They then mixed these sediments with purified water and sealed one set of samples and bubbled CO2 through the other set. The amount of CO2 used is unreasonably large and concentrated and was performed on very small amounts of powdered sediment samples. This method will always produce the maximum chemical reaction result, as the natural fabric of the sediment has been disrupted and a much greater proportion of reactive surfaces are exposed to the CO2. Many natural CO2 springs exist in the USA and Europe, where the sparkling waters are drunk and bathed in for their health benefits. Some of these do have elevated cations and even metals in their analyses but not to harmful amounts. If CO2 bubbling through rock was this dangerous, then humans wouldn't be able to drink sparkling water with such impunity.