The document discusses various types of water pollution including chemical, thermal, radioactive, sediments, and sewage. The largest sources of water pollution are agricultural runoff and sewage. Developing countries often lack proper sewage treatment facilities. Water pollution has been an issue for centuries but legislation and enforcement have been weak, allowing the problem to continue. The top source of water pollution in North Carolina is stormwater runoff carrying various pollutants. Solutions include limiting development near waterways and preserving wetlands to naturally filter water.