Early geothermal direct use developments utilized natural or improved hot springs. In some cases the discharge released some undesirable, or in a few cases, constituents that are now considered hazardous, to the surface - usually into streams. Even so, one could reasonably argue that injection would not be required because the springs flowed to the surface away and only some heat was removed before releasing the same flow at some slightly removed location. As further development proceeded, wells were drilled nearby to obtain more hot water. Continued development and pumping sometimes cause the springs to dry up, but the pumped water was basically the same and disposal was still to the surface