The following is a partial list of toxic substances and pathogenic bacteria the discharge of which into the County sewerage system or sewers tributary thereto is hereby prohibited unless their concentration 1) is reduced by treatment at the source to a point that will meet the general purposes of these rules and regulations or come within the applicable standards set forth herein or under Article VII; 2) will not adversely affect any of the biochemical, chemical or other sewage treatment processes:
A. 
Antibiotics.
B. 
Arsenic.
C. 
Bromine, iodine, chlorine.
D. 
Chloroform.
E. 
Copper and copper salts.
F. 
Creosols and creosotes.
G. 
Fluorides.
H. 
Formaldehyde.
I. 
Mercury and mercurials.
J. 
Phenolic compounds.
K. 
Silver and silver compounds.
L. 
Sulfonamides, toxic dyes (organic or mineral).
M. 
Tetrachloroethylene.
N. 
Zinc compounds.
O. 
All strong oxidizing agents such chromates, dichromates, permanganates, peroxides, etc.
P. 
Chemical compounds producing toxic, flammable or explosive gases, either upon acidification, alkalization, oxidation or reduction.
Q. 
Strong reducing agents such as nitrites, sulfides, sulfites, thiosulfates, etc.
R. 
Wastes from industrial processes or hospital procedures containing viable pathogenic organisms.
The concentration in sewage of any of the following toxic substances shall not exceed these concentrations judged by the Director to be toxic to biological sewage treatment processes or to the biota of the receiving waters and shall not in any case exceed the following limits when such sewage is discharged to a public sewer. These limits may be revised by the Commission whenever operating experience indicates that it is desirable or the limits are superseded by Federal Categorical Pretreatment Standard if and when more stringent standards are promulgated.
Toxic Substance
Maximum Permissible Discharge Concentration
(milligrams per liter)
Cadmium
2.0
Chromium (hexavalent)
5.0
Copper
3.0
Cyanate
10.0
Cyanide
1.0
Mercuric chloride
2.0
Nickel
10.0
Silver
0.05
Zinc
5.0
Zirconium
10.0
Bromine, iodine, chlorine
100.0
A. 
When the volume of a single toxic industrial waste discharge or the combined toxic industrial waste discharges of a group of industries within a single contributory area is so large that an excessive volume of toxic waste will enter a treatment plant, the Director may impose lower concentration limits upon the contributors. Conversely, where a toxic industrial waste discharge will be effectively removed by the treatment works or will be rendered innocuous before reaching a treatment plant or the receiving waters, the Director may permit toxic industrial waste discharge concentrations greater than those hereinbefore listed, provided the higher concentration does not constitute a toxicity hazardous to maintenance workers, and does not cause any deleterious effects of any kind to the treatment process or receiving waters and meets the requirements of Article VII of this chapter.
B. 
To assure that none of the above-noted limitations are violated, the Director shall issue permits to significant industrial users, with the potential of discharging any of the before-mentioned pollutants, limiting the discharge of the substances noted above. Each permit shall restrict the discharge from each significant industrial user to a portion of the total allowable influent loading.
(1) 
In determining what portion of the total of each substance that each significant industrial user shall be allowed to discharge, the Director shall consider:
(a) 
The quantities of each substance that are uncontrollable because they occur naturally in wastewater;
(b) 
The quantities of each substance that are anthropogenic but are nonetheless uncontrollable;
(c) 
Historical discharge trends;
(d) 
Past pollution control efforts of each significant industrial user compared to other significant industrial dischargers of the same substance;
(e) 
Potential for growth in the POTW service area;
(f) 
Potential for more restrictive regulatory requirements to be placed on the POTW discharge or sludge disposal or sludge reuse method; and
(g) 
Treatability of the substance.
(2) 
The Director shall apply a minimum 20% safety factor to be protective of the POTW.