pollution has a negative impact on the environment / air quality / water quality / society & runoff from a cropland causes water pollution ->  runoff from cropland has a negative impact on water quality  runoff from cropland has a negative impact on water quality & a lake is a kind of body of water & runoff is when cropland water enters bodies of water ->  runoff from a cropland entering a lake has a negative impact on water quality in that lake  runoff from a cropland entering a lake has a negative impact on water quality in that lake & water is a kind of natural resource -> runoff from a cropland entering a lake has a negative impact on a natural resource by having a negative impact on water quality