Runoff is one of many causes for the detrimental impacts on our waters. The main cause of runoff is due to urbanization near coastlines or waterways. Whenever it rains, the water flows through these sites, making its way through fertilizer, pesticides, bacteria, and pollutants and continues to finalize it’s journey through storm drains and landing in any body of water downhill from it. These harmful pollutants change the pH and affect the health of organisms living in the water. Polluted runoff is one of the main threats to our underwater worlds because of the fact that urbanization is growing so rapidly to this day. Not only does this runoff affect the organisms and ecology, but it also contaminates our clean drinking water from springs and streams, limiting what we can use for human consumption. All in all, contaminated runoff is affecting ecosystems across the globe and will lead in the cause of ocean defilement.