WHAT ARE THE ENVIRONMENTAL IMPACTS OF SEPTIC SYSTEMS?
A system that is properly designed and maintained will contribute clear water, nitrate, and very small amounts of salts to the groundwater supply. Nitrate migrates with groundwater to nearby streams and the river and may encourage algae to grow, which can be both good and bad. Small invertebrates that are the main food source for fish and other wildlife need algae for food and habitat but too much algae may be unsightly and adversely affect swimming areas. Decomposing algae may also impart a moldy taste to the water. When the water is used to supply drinking water needs, as is the case with the San Lorenzo River, it must be treated to reduce odor before distribution. Nitrate in very high concentrations is also toxic to humans and can render a water source unfit for human use. Current septic system repair and new system standards are designed to ensure that nitrate in groundwater and surface water never reach dangerous levels. A failing septic system will allow large amounts of viruses
