Inflow and infiltration in coastal wastewater collection systems: effects of rainfall, temperature, and sea level.

Wastewater collection and treatment systems are vital to public health, economic growth, and environmental quality, but do not receive as much consideration for upgrades and improvements as other forms of public infrastructure. Extraneous inputs to a wastewater collection system are caused by rainfall and submergence ("Inflow and infiltration," I&I) and other factors, such as variation in sea level in coastal settings. These factors all pose risks for system degradation, sanitary system overflows (SSOs), and water quality impairment, but remain poorly quantified.

Rainfall effects on inflow and infiltration in wastewater treatment systems in a coastal plain region.

Aging wastewater collection and treatment systems have not received as much attention as other forms of infrastructure, even though they are vital to public health, economic growth, and environmental quality. Inflow and infiltration (I&I) are among potentially widespread problems facing central sewage collection and treatment systems, posing risks of sanitary system overflows (SSOs), system degradation, and water quality impairment, but remain poorly quantified. Whole-system analyses of I&I were conducted by regression analyses of system flow responses to rainfall and temperature for 93 wastewater treatment plants in 23 counties in eastern North Carolina, USA, a coastal plain region with high water tables and generally higher rainfalls than the continental interior.

Microembolic signals detected by transcranial Doppler sonography during carotid endarterectomy and correlation with serial diffusion-weighted imaging.

Background And Purpose: Embolic events are a major cause for procedure-related strokes after carotid endarterectomy (CEA). Transcranial Doppler sonography can reveal embolic events as microembolic signals (MES) during CEA. MES during declamping and shunting are frequently detected.