Effluent Concentrations from EPA's Development Document
Process Summary for Mechanically Butchered Salmon

Daily monitoring reports (DMR) are often inadequate for determining likely effluent wastewater characteristics because representative sampling may not be occurring.  Omission of key pollutant parameters in specific discharge categories also leaves gaps in the effluent concentration data.  An important solution to these problems is to source the original EPA development document to obtain reliable effluent concentration data to be used in mixing zone modeling and ambient water quality evaluation.  These EPA development documents for effluent limitations guidelines are the basis of many pollutant limits in regulatory NPDES permits.

 

Process effluent summaries are contained, for example, in the Development Document for Effluent Limitations Guidelines and New Source Performance Standards for the Fish Meal, Salmon, Bottom Fish, Clam, Oyster, Sardine, Scallop, Herring, and Abalone Segment of the Canned and Preserved Fish and Seafood Processing Industry Point Source Category: Group 1, Phase II [EPA, September 1975].  Consider the Mechanically Butchered Salmon (MBS) process summary for EPA selected parameters in Table 1(MBS).  This table is derived from Table 22 of the Development Document (p. 91).

 

Table 1(MBS).  Mechanically Butchered Salmon Process Summary for EPA Selected Parameters

 

The mean value of 2,750 mg/l for biochemical oxygen demand (five-day, i.e., BOD₅) for Mechanically Butchered Salmon is reported by the EPA as summarized in Table 1(MBS).  For comparison, this value is over 14.4 times greater than the medium strength of untreated domestic wastewater of 190 mg/l [see reference 1].  Domestic wastewater, which includes untreated raw sewage, typically requires secondary treatment to reduce BOD₅ to 45 mg/l on a weekly average basis, and 30 mg/l on a monthly average basis [2].  When high range BOD₅ concentrations are considered, the 99 percent maximum value of 3,670 mg/l for MBS is over 10.4 times greater than the 350 mg/l value for high strength untreated domestic wastewater.

 

Values for total suspended solids (TSS), and oil and grease (O&G), are also considerably higher for MBS than for untreated domestic wastewater.  The mean TSS value of 1,100 mg/l for MBS is over 5.2 times greater than the concentration of 210 mg/l for medium strength untreated domestic wastewater [1].  The 99% maximum TSS value of 1,480 mg/l for MBS is 3.7 times greater than the concentration of 400 mg/l for high strength untreated domestic wastewater.

 

The mean O&G value of 351 mg/l for MBS is 3.9 times greater than the concentration of 90 mg/l for medium strength untreated domestic wastewater [1].  The 99% maximum O&G value of 1,430 mg/l for MBS is 14.3 times greater than the concentration of 100 mg/l for high strength untreated domestic wastewater. 

 

[1]  Wastewater Engineering – Treatment and Reuse, Metcalf & Eddy, 4th Edition revised by Tchobanglous, et al., McGraw-Hill, 2003, Table 3-15, pp. 186-187.

 

[2]  Ibid., pp. 3-9.