While determining the performance of your community’s septic systems can be difficult, there are some telltale signs of underperforming systems. Obvious indications include backed-up plumbing, standing water in yards or bad odors. But symptoms of poorly functioning septic systems can extend further than your backyard. The nutrient overloading caused by poorly performing systems can lead to water pollution that takes a toll on surrounding water bodies. If nearby waterways have issues with algal blooms or “dead zones,” it is likely that human waste is a major factor. Drinking water may also contain more nitrogen, which is dangerous to consume in even modest quantities.