The role of sewer lines as preferential pathways for vapor intrusion is poorly understood. Although the importance of sewer lines for volatile organic compound (VOC) transport has been documented at a small number of sites with vapor intrusion, sewer lines are not routinely sampled during most vapor intrusion investigations. We have used a tracer study and VOC concentration measurements to eval...

the 6th national population and housing census was carried out from october 28 to november 17, 2006 in which three different questionnaires were used. question number 55 of the 3rd questionnaire asked about housing units sewage disposal. this paper studies and analyzes the answers to the mentioned question in regional and national levels. assessment of housing units sewage disposal conditions s...

This paper describes the design and implementation of multimedia data processing elements for a home sewer platform. Generally, a home sewer can be considered as an integrated form of a multimedia data sewer, home control sewer, and home information sewer. As a multimedia data sewer, the proposed scheme has a digital TV receiver module and a multimedia codec module. Thus, watching digital TV an...

Sewer line failures are a major cause of stream impairment in urban areas. While many sewer line failures can be readily identified and corrected, other failures may be more difficult to remedy. This paper examines the general problem of sewer line failures. Specifically, we discuss 1) the observed causes of sewer line failures, 2) methods for determining which streams are being affected by sew...

Biological nutrient removal (BNR) technology can suffer poor performance or complete failure due to the fastidious nature of the bacteria used in the system. The bacteria involved necessitate strict operating conditions, multiple zones with one or more recycling lines, carbon source augmentation, and efficient aeration. For wastewater treatment plants receiving significant combined sewer overfl...

Sewers are aging, expensive assets that attract public attention only when they fail. Sewer operators are under increasing pressure to minimise their maintenance costs, while preventing sewer failures. Inspection can give early warning of failures and allow economical repair under noncrisis conditions. Current inspection techniques are subjective and detect only gross defects reliably. They can...

Inflow/infiltration (I/I) and infiltration/exfiltration (I/E) are interactive processes which dynamically affect sewer and groundwater performance. The incidence and condition of "critical" sewers in the UK are identified together with methods of quantifying I/I and I/E as well as their impact on wet weather sewer performance and on urban groundwater pollution. Whilst the impacts of sewer trenc...

Separate sanitary sewer systems are designed to convey sewage waste from municipal areas to a central treatment facility; they are not designed to handle water associated with precipitation events. However, intercept of groundwater (infiltration) and of flows through manholes or unauthorized connections (inflows) introduces rainwater into the sanitary sewer system. Infiltration/Inflow (I/I) inc...

The formation and fate of sulfide in a force main and a downstream-located gravity sewer were investigated in an extensive field study. Sulfide formation in the force main was significant. However, during 14 minutes of transport in the gravity sewer, the sulfide concentration decreased 30%, on average. An application of a conceptual sewer process model for simulating the formation and fate of s...

Sewer systems are large-scale systems that collect and transport stormwater and sanitary sewage out of urban areas. Sewer systems are mainly operated using pumping stations and pollutants are removed from sewage by treatment plants before water is released into the environment. When a sewer overflow occurs, e.g., caused by a strong rainfall, sewage is discharged directly into the environment wi...