Wastewater treatment discharge points

Step 9.1 Identify the Effluent Discharge Points. Determine the points at which wastewater leaves the site. Wastewater may go to an effluent treatment plant, directly to a public sewer, or directly to a watercourse. One factor that is often overlooked in audits is the use of several discharge points. It is important to identify the location, type, and size of all discharge flows. Identify where flows from different unit operations or process areas contribute to the overall flow. In this way, it is possible to piece together the drainage network for the site. This can lead to startling discoveries of what goes where ... 

Enter the applicable letter code for the receiving stream or water body from Section 3.10 of Part I of the form. Also, enter the total annual amount of the chemical released from all discharge points at the facility to each receiving stream or water body. Include process outfalls such as pipes and open trenches, releases from on-site wastewater treatment systems, and the contribution from stormwater runoff, if applicable (see instructions for column C below). Do not include discharges to a POTW or other off-site wastewater treatment facilities in this section. These off-sife transfers must be reported in Pari III, Section 6 of the form. 

The Willamette River Basin, Oregon serves as an excellent case study of river quality assessment for a number of reasons. First, the Willamette River has been cited internationally as a classic example of how water quality can be restored from a previously poor quality waterway (1-3). Second, excellent background data were available, particularly on hydrology. Third, at the time most of these studies were initiated, the Willamette River was the largest river in the U.S. for which all point-source discharges were receiving secondary wastewater treatment. 

FIGURE 21.9 Schematic diagram of the IP Jay Paper Mill showing points of discharge to wastewater treatment plant. (Taken from U.S. EPA, International Paper XL-2 Effluent Improvements Project, Final Report, U.S. EPA, Maine Department of Environmental Protection, Jay, Maine, September 6, 2005.)... 

The main points of collection and subsequent release of these contaminants into the environment are wastewater treatment plants (WWTPs), where they enter via domestic and hospital sewages or industrial discharges [1]. Some of them are more likely accumulated in sewage sludge, due to their moderate to high hydrophobic... 

Chemical pollution From a qualitative point of view, an important common issue is the excess of chemicals (fertilisers and pesticides) associated with agrarian and livestock farming diffuse sources and the point-source discharge of (treated and untreated) sewage water. Industrial point-source pollution is not addressed as a relevant issue, but it is assumed that industries operate following the legal rules and only the incomplete elimination of industrial chemicals in urban wastewater treatment plants is perceived as a problem. 

Pesticides in wastewaters come typically from point sources of contamination such as disposal sites and landfills where industrial or agricultural wastes are buried without any consideration, as well as discharges from industrial effluents from pesticide production plants. Furthermore, nonpoint sources derived from regular agricultural activities, especially in intensive agricultural areas, and accidental spills can also be significant. Urban use of pesticides is also possible in large cities where the use of herbicides and insecticides may result in runoff into the sewers. These sewers in turn may expel pesticides into wastewater treatment plants (WWTPs). 

On-line or on-site toxicity evaluation is a great challenge due to the complexity of measuring the different impacts (from trouble from to death of organisms) of several substances, the effect of which is often increased by synergy. Furthermore for wastewater, toxicity monitoring must be implemented in several locations raw sewer, treatment plant or discharge point. Toxicity can be eval-... 

The levels of LAS detected depend largely on whether the site at which samples are taken has any wastewater effluent points or treatment plants in the vicinity, and on the distance between the discharge point and the site. In turn, the influence of the main processes participating in the removal of LAS from the medium (biodegradation, dilution,... 

Figure 2.7 Number of PPCPs (top panel) and total concentration of analytes (bottom panel) found at 10 wastewater treatment locations witbin tbe United States. Samples were taken from an immediate up-stream location, tbe wastewater effluent, and two points, DS1 and DS2 downstream of tbe plant. DS2 was always further downstream compared to DSl. The plant in Arizona did not have any up-stream point as the stream was entirely a result of the treatment plant discharge. (Based on data from Glassmeyer et al., 2005.)...

Prior to 1972, water quality regulations were limited to point sources. A point source is a single source, such as a commercial facility or municipal wastewater treatment, that discharges effluent directly into a waterway. With the CWA, water quality was expanded to encompass nonpoint sources. Nonpoint sources often associated with waste from runoff (agricultural, mine tailings, etc.) are those contaminant sources whose origin cannot be identified. 

Comment This exclusion applies only to the actual point source discharge. It does not exclude industrial wastewaters while they are being collected, stored or treated before discharge, nor does it exclude sludges that are generated by industrial wastewater treatment). 

Point sources are pollution sites that have a definite identifiable source. Discharges from a chemical industry or raw sewage from wastewater treatment plants are common examples of point-source pollution. Point sources are easy to identify, control, and regulate. The Environmental Protection Agency (EPA) is the governmental agency that regulates point sources. 

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