For example, fertilizers and pesticides used on farmland as well as contributions from livestock, can leak into surface water sources if not carefully monitored. (scientificamerican.com)
«As surface water sources became more scarce during a given climate cycle, the only species to survive may have been those with adaptations for sufficient mobility to discover a new and more persistent groundwater source, or those already settled within home range of such a resource,» co-author Professor Gail Ashley, Rutgers University (US), said. (sciencedaily.com)
The tap water we drink, cook with, and bathe in typically comes from either surface water sources like streams, rivers, lakes, and reservoirs, or from underground sources like aquifers, permeable rocks that can store and transmit water. (scientificamerican.com)