Data on groundwater water quality have now been updated for the year 2020 under index 2.4.

Temperature, conductivity, chromium, arsenic, and silica concentrations are monitored at Gaumur. Measurements of groundwater in springs by Lake Mývatn, in Kelduhverfi, and in Þeistareykir are carried out annually for the purpose of assessing the impact of wastewater from geothermal power plants on the groundwater. Measurements carried out in 2020 do not show any major changes from previous years. Sampling usually takes place in August and September, but due to production stoppage in Krafla, sampling took place in October of the power plant's wastewater.

Environmental limits for the concentration of metals in surface water for the protection of ecosystems have been set out in regulation on the prevention of water pollution. The environmental limits are displayed under index 2.4. The concentration of arsenic at all sampling points has been below the environmental limit I for the concentration of arsenic and therefore there is little or no risk of the negative effects of arsenic on groundwater. The concentration of chromium is below the environmental limit II for the concentration of chromium in groundwater, which means that there is little risk of a negative environmental impact due to chromium.