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 fish meal no solubles plant (FMN) process summary for EPA
selected parameters in Table 1(FMN).
This table is derived from Table 21 of the Development
Document (p. 79).
Table 1(FMN). Fish Meal Without Solubles Plant (i.e., without Evaporator)
Process Summary for EPA Selected Parameters
|
|
|
|
Log Normal Mean |
Log Normal STD
DEV |
99% Maximum |
|
Production |
ton/hr |
7.60 |
NGA |
1.48 |
NG |
|
Time |
hr/day |
15.7 |
NG |
11.8 |
NG |
|
Flow |
gpm |
208 |
NG |
204 |
NG |
|
Flow Ratio |
gal/ton |
456 |
6.12 |
0.120 |
602 |
|
TSS |
mg/l |
18,300 |
9.81 |
0.273 |
34,500 |
|
BOD5 |
mg/l |
32,700 |
10.4 |
0.144 |
45,700 |
|
Oil & Grease |
mg/l |
12,000 |
9.39 |
0.534 |
41,600 |
|
pH |
S.U. |
6.80 |
NG |
0.026 |
NG |
The
mean value of 32,700 mg/l for biochemical oxygen demand (five-day, i.e., BOD5)
for fish meal without solubles plant is reported by the EPA as summarized in Table
1(FMN). For comparison, this value is
over 172 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 45,700 mg/l for FMN is over 130 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 FMN than for untreated domestic wastewater. The mean TSS value of 18,300 mg/l for FMN is
over 87 times greater than the concentration of 210 mg/l for medium strength
untreated domestic wastewater [1]. The
99% maximum TSS value of 34,500 mg/l for FMN is over 86 times greater than the
concentration of 400 mg/l for high strength untreated domestic wastewater.
The
mean O&G value of 12,000 mg/l for FMN is over 133 times greater than the
concentration of 90 mg/l for medium strength untreated domestic wastewater
[1]. The 99% maximum O&G value of
41,600 mg/l for FMN is over 416 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.