Meteorological influences on nitrogen dynamics of a coastal onsite wastewater treatment system.

On-site wastewater treatment systems (OWTS) can contribute nitrogen (N) to coastal waters. In coastal areas with shallow groundwater, OWTS are likely affected by meteorological events. However, the meteorological influences on temporal variability of N exports from OWTS are not well documented. Hydrogeological characterization and seasonal monitoring of wastewater and groundwater quality were conducted at a residence adjacent to the Pamlico River Estuary, North Carolina, during a 2-yr field study (October 2009-2011). Rainfall was elevated during the first study year, relative to the annual mean. In the second year, drought was followed by extreme precipitation from Hurricane Irene. Recent meteorological conditions influenced N speciation and concentrations in groundwater. Groundwater total dissolved nitrogen (TDN) beneath the OWTS drainfield was dominated by nitrate during the drought; during wetter periods, ammonium and organic N were common. Effective precipitation (precipitation [P] minus evapotranspiration [ET]) affected OWTS TDN exports because of its influence on groundwater recharge and discharge. Groundwater nitrate-N concentrations beneath the drainfield were typically higher than 10 mg/L when total biweekly precipitation was less than evapotranspiration (precipitation deficit: P < ET). Overall, groundwater TDN concentrations were elevated above background concentrations at distances >15 m downgradient of the drainfield. Although OWTS nitrate inputs caused elevated groundwater nitrate concentrations between the drainfield and the estuary, the majority of nitrate was attenuated via denitrification between the OWTS and 48 m to the estuary. However, DON originating from the OWTS was mobile and contributed to elevated TDN concentrations along the groundwater flowpath to the estuary.

Onsite wastewater system nitrogen contributions to groundwater in coastal North Carolina.

The objective of the study described in this article was to evaluate the nitrogen contributions from two onsite wastewater systems (sites 1 and 2) to groundwater and adjacent surface waters in coastal Beaufort County, North Carolina. Groundwater levels and water quality parameters including total nitrogen, nitrogen species, temperature, and pH were monitored from October 2009 to May 2010. Nitrogen was also tested in groundwater from deeper irrigation or drinking water wells from the two sites and six additional neighboring residences. Mean total nitrogen concentrations in groundwater beneath onsite wastewater systems 1 and 2 were 34.3 +/- 16.7 mg/L and 12.2 +/- 2.9 mg/L, respectively, and significantly higher than background groundwater concentrations (< 1 mg/L). Groundwater in the deeper wells appeared not to be influenced by the onsite systems. Groundwater nitrogen concentrations typically decreased with distance down-gradient from the systems, but were still elevated relative to background conditions more than 15 m from the systems and near the estuary. This was a pioneering effort to better understand the link of onsite systems, the fate of nitrogen in the environment, and public health.

Similarities and differences on five inventories among mood and anxiety disorder patients.

The Eysenck Personality Questionnaire (EPQ), BAROMAS, Leisure Interests Checklist (LIC), Mental Health Inventory (MHI) and a one-page checklist of Body Problems were given to 128 outpatients with serious mood or anxiety disorders. Compared to normative data published on the first four devices, the combined patients were far 'sicker' in nearly all comparisons (P less than or equal to 0.01). However, anxiety and mood patients did not differ on the EPQ, BAROMAS, or LIC. On Body Problems, strong contrasts emerged (P less than 0.04), especially when 'fringe' cases were excluded (e.g. dysthymics from mood, and obsessives from anxiety disorder diagnoses). Small anxiety subtype groups also differed (P less than 0.05). On the MHI, both global and core groups of mood--especially unipolar (depressed)--patients differed from the anxiety disorders (P less than 0.04).

Increased plasma tricyclic antidepressant concentrations in two patients concurrently treated with fluoxetine.

Two patients taking stable doses of standard tricyclic antidepressants were additionally treated with fluoxetine as the first step in a transition to that drug. After fluoxetine was added, both patients' plasma tricyclic antidepressant levels increased substantially. Adverse side effects occurred in one patient. Fluoxetine may increase the plasma levels of standard tricyclic antidepressants and the likelihood of tricyclic antidepressant toxicity.