Upon the promulgation of the national categorical pretreatment
standards for a particular industrial subcategory, the national standard,
if more stringent than limitations imposed under this chapter for
sources in that subcategory, shall immediately supersede the limitations
imposed under this chapter. The Director or Chief Operator shall notify
all affected users of the applicable reporting requirements under
40 CFR 403.12.
Where the City's wastewater treatment system achieves consistent
removal of pollutants limited by national pretreatment standards,
the City may apply to the approval authority for modification of specific
limits in the national pretreatment standards. "Consistent removal"
shall mean reduction in the amount of a pollutant or alteration of
the nature of the pollutant by the wastewater treatment system to
a less toxic or harmless state in the effluent which is achieved by
the system in 95% of the samples taken when measured according to
the procedures set forth in 40 CFR Part 403, General Pretreatment
Regulations for Existing and New Sources of Pollution, promulgated
pursuant to the Act. The City may then modify pollutant discharge
limits in the national pretreatment standards if the requirements
contained in 40 CFR 403.7 are fulfilled and prior approval from the
approval authority is obtained.
A.Â
No user shall discharge wastewater to the sanitary sewer system when
any of the pollutant concentrations exceed the limits specified in
the following. These concentrations shall be applied to wastewater
effluents at a point just prior to discharge into the City sewer system.
With the express written consent of the Director of the Department
of Public Works or the Chief Operator of the POTW, users with multiple
discharge outfalls may combine waste streams by calculation to report
on wastewater characteristics.
|
Table 1
| |
|---|---|
|
Substance
|
Concentration Limit
(mg/L)
|
|
Arsenic
|
0.10
|
|
Cadmium
|
0.20
|
|
Cyanide-complex
|
0.80
|
|
Chromium, hexavalent
|
0.10
|
|
Chromium-total
|
1.00
|
|
Copper
|
1.00
|
|
Iron
|
10.0
|
|
Lead
|
0.10
|
|
Mercury
|
0.001
|
|
Nickel
|
2.00
|
|
Selenium
|
0.05
|
|
Silver
|
0.10
|
|
Zinc
|
0.60
|
|
Phenolic compounds
|
5.00
|
|
Oil and grease
|
100.00
|
|
Sulfide
|
3.00
|
B.Â
The Director of the Department of Public Works may impose mass limitations
in addition to the concentration-based limitations above. The Director
may also develop and impose limitations on additional parameters on
a case-by-case basis.
A.Â
No person shall discharge or permit the discharge or infiltration
into the City sewer system of wastes containing the following pollutants
in excess of the listed concentrations unless prior approval is granted
by the Director or Chief Operator of the POTW:
(1)Â
Wastes containing more than 200 mg/l of five-day biochemical oxygen
demand (BOD).
(2)Â
Wastes containing more than 200 mg/l of total suspended solids (TSS).
(3)Â
Wastes containing more than 100 mg/l of total organic carbon (TOC).
(4)Â
Wastes containing more than 400 mg/l of chemical oxygen demand (COD).
(5)Â
Wastewater in volumes constituting greater than 25,000 gallons/day.
State requirements and limitations on discharges shall apply
in any case where they are more stringent than national requirements
and limitations or those in this chapter.
No user shall ever increase the use of process water or in any
way attempt to dilute a discharge as a partial or complete substitute
for adequate treatment to achieve compliance with the limitations
contained in the national categorical pretreatment standards, or in
any other pollutant-specific limitation developed by the City or state.
