Many states and cities are currently struggling to establish maximum daily loads for bacterial pollutants in local streams. If the basic assumption about the cause of this contamination is incorrect, then the decisions that they make are likely to be inappropriate, Thackston argues. So he urges regulators to do the additional testing required to differentiate between the two causes of pollution so that they can make informed decisions on the matter. Animal wastes are not considered to be as dangerous as human wastes, because the bacteria they contain are not as likely to attack humans. However, exposure to animal feces can cause gastric distress and, along with other organic wastes like grass clippings, leaves and garbage, they can taint fresh streams and rivers, robbing them of oxygen and killing aquatic life.
Animal wastes contain higher levels of another bacteria, fecal streptococci.
As a result, when the ratio of coliform to streptococci bacteria is low, researchers consider it to be a strong indication that the source is primarily animal rather than human. The researchers also found that bacterial levels in local runoff were 10 times higher in the sewered areas than it was in the less heavily developed areas with septic tanks. In fact, the researchers found that the higher the housing density in a neighborhood, the higher the level of contamination. Two factors contribute to the pet pollution problem, the water pollution expert says. One is the sheer number of pets in urban areas.