Onsite wastewater disposal systems (OWDS) in coastal regions of Long Island, New York, contribute bacteria, nutrients, and organic wastewater-associated compounds (including pharmaceuticals, personal care and domestic use products referred to here as contaminants of emerging concern (CECs)) to downgradient shallow groundwater in nearshore settings. Many of the densely populated areas along the East Coast (i.e. Long Island, New York) are served by OWDS. Approximately 75 percent of Suffolk County, New York, residents rely on simple OWDS such as a series of cesspools (ground pits lined with cement blocks or rings without a sealed bottom) and septic systems. Cesspools provide minimal wastewater treatment, typically relying on bacteria to breakdown the solid waste while untreated water percolates into the sandy surficial aquifer. The high hydraulic conductivity of the sandy surficial aquifer of the New York coastal region makes these areas particularly vulnerable to organic wastewater contamination. Groundwater samples were collected from the shallow groundwater flow system along the shoreline of (1) a barrier island summer community and (2) the mainland of Long Island. Both locations are distinctive coastal communities in Suffolk County, N.Y., and typically rely on a simple OWDS system. The coastal communities selected are in areas inundated by the storm tide brought on by Hurricane Sandy and are considered vulnerable to extreme storms (i.e. hurricanes and nor’easters), flooding events, and sea-level rise; all of which can damage wastewater infrastructure and lead to biogeochemical changes that disrupt the level of onsite treatment and result in increased discharge of contaminants to estuaries through groundwater seepage. Specific locations were selected in areas along the shore that are within 180 m downgradient from OWDS and just above the reaches of the spring high-tide mark along the shoreline. For our study, beach areas without bulkheads (a retaining wall built for shoreline protection) were targeted due to the need to access areas downgradient of OWDS.
Twenty-nine of the 103 pharmaceuticals measured were detected at least once at the N.Y. sample locations. Other detected CECs include PCDUs (caffeine, nicotine, and metabolites), methyl-1H-benzotrizole (a corrosion inhibitor), and piperonyl butoxide (a pesticide synergist). Lidocaine, an over-the-counter topical anesthetic, was the most commonly detected pharmaceutical (35% of samples). Other commonly detected pharmaceuticals included fexofenadine (an over-the-counter antihistamine detected in 30% of samples), and carbamazepine (an anticonvulsant), desvenlafaxine (antidepressant), meprobamate (an anxiolytic), metformin (an antidiabetic), and tramadol (an opioid) each detected in 25% of the samples.