Liberte Environmental Associates

Effluent Concentrations from EPA's Development Document
Process Summary for Scallop




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 Scallop process summary for EPA selected parameters in Table 1(Scallop). This table is derived from Table 39 of the Development Document (p. 166).

 

Table 1(Scallop). Scallop Process Summary for EPA Selected Parameters


Parameter

 


Mean

Log Normal Mean

Log Normal STD DEV

99% Maximum

Production

ton/hr

1.26

NGA

0.304

NG

Time

hr/day

8.63

NG

4.05

NG

Flow

gpm

40.5

NG

55.2

NG

Flow Ratio

gal/ton

515

6.243

2.615

228,000

TSS

mg/l

325

5.783

0.923

2,790

BOD5

mg/l

1,460

7.286

0.200

2,330

Oil & Grease

mg/l

20.1

3.003

2.221

3,560

pH

S.U.

6.66

NG

NG

NG

ANG-Not Given by EPA.

 

The mean value of 1,460 mg/l for biochemical oxygen demand (five-day, i.e., BOD5) for Scallop is reported by the EPA as summarized in Table 1(Scallop). For comparison, this value is over 7.6 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 2,330 mg/l for Scallop is over 6.6 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 Scallop than for untreated domestic wastewater. The mean TSS value of 325 mg/l for Scallop is over 1.5 times greater than the concentration of 210 mg/l for medium strength untreated domestic wastewater [1]. The 99% maximum TSS value of 2,790 mg/l for Scallop is over 6.9 times greater than the concentration of 400 mg/l for high strength untreated domestic wastewater.

 

The mean O&G value of 20.1 mg/l for Scallop is only 0.22 times the concentration of 90 mg/l for medium strength untreated domestic wastewater [1]. However, the 99% maximum O&G value of 3,560 mg/l for Scallop is 35.6 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.