Methane (IMAGE) University of Cincinnati Caption A time-series map shows the Ohio counties where UC researchers collected water samples. Red circles indicate active natural gas wells. Blue diamonds are sites where time series groundwater samples were taken. Light blue circles represent sites where a single sample of groundwater was collected. Groundwater sample locations are noted when samples were taken between the years noted in each map. There was a large increase in active natural gas wells from 2013 to 2014. Credit Claire Botner/UC Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.