Phosphorus pollution comes from multiple sources , including fertilizer and manure that enter the water through runoff .
磷污染有多個(gè)來源,包括化肥和糞肥通過徑流進(jìn)入水源。
Differences in brightness in coastal area waters may be due to other factors , including freshwater runoff , strong currents , and water depth and clarity .
These opinions recognize that current farming methods bring serious environmental problems involving water supplies , fertilizer runoff and energy use .