(See References 1). Fertilizer pollution is harder to regulate and reduce than many other kinds of water pollution because it is a type of nonpoint source pollution. A point source -- which comes from one definable location, such as a factory -- is easier to track.But fertilizers are used on private lawns, in agricultural fields and on golf courses. Manure contains high levels of nitrogen and phosphorus and causes the same ecological problems as artificial fertilizers. point source -- which comes from one definable location, such as a factory -- is easier to track. But fertilizers are used on private lawns, in agricultural fields and on golf courses. Manure contains high levels of nitrogen and phosphorus and causes the same ecological problems as artificial fertilizers.