Wastewater-contaminated groundwater as a source of endogenous hormones and pharmaceuticals to surface water ecosystems.

Increasing residential development in watershed recharge areas increases the likelihood of groundwater and surface water contamination by wastewater effluent, particularly where on-site sewage treatment is employed. This effluent contains a range of compounds including those that have been demonstrated to mimic or interfere with the function of natural hormones in aquatic organisms and humans. To explore whether groundwater contaminated by discharge from on-site septic systems affects water quality in surface water ecosystems, we measured steroidal hormones, pharmaceuticals, and other organic wastewater compounds (OWCs) in water collected from six aquifer-fed ponds in areas of higher and lower residential density on Cape Cod (Massachusetts, USA).