§ 20-99. Restricted discharges.

Except in quantities, or concentration, or with provisions as stipulated herein, it shall be unlawful for any person to discharge water or wastes to the sanitary sewer containing:

(1)

Free or emulsified oils and grease exceeding on analysis an average of one hundred (100) parts per million (eight hundred thirty-three (833) pounds per million gallons) of either or both or combinations of free or emulsified oil and grease, if, in the opinion of the manager, it appears probable that such wastes:

a.

Can deposit grease or oil in the sewer lines in such a manner as to clog the sewers;

b.

Can overload skimming and grease handling equipment;

c.

Are not amenable to bacterial action and will, therefore, pass to the receiving waters without being affected by normal sewage treatment processes, or;

d.

Can have deleterious effects on the treatment process due to the excessive quantities.

(2)

Acids or alkalies which attack or corrode sewers or sewage disposal structures or have a pH value lower than 5.5 or higher than 9.5;

(3)

Cyanide or cyanogen compounds capable of liberating hydrocyanic gas on acidification in excess of one-half (0.5) parts per million by weight as CN in the wastes from any outlet into the public sewers;

(4)

Materials which exert or cause:

a.

Unusual concentrations of solids or composition; as for example, total suspended solids of greater than two hundred fifty (250) parts per million of inert nature (such as Fuller's earth) and/or total dissolved solids such as sodium chloride, or sodium sulfate;

b.

Excessive discoloration;

c.

Biochemical oxygen demand or an immediate oxygen demand greater than two hundred and fifty (250) parts per million;

d.

High hydrogen sulfide content, or

e.

Unusual flow and concentration shall be pretreated to a concentration acceptable to the city's water and sewer system if such wastes can cause damage to collection facilities, impair the processes, incur treatment cost exceeding those of normal sewage, or render the water unfit for stream disposal or industrial use.

(Ord. No. 7206, § 2(B), 12-7-72)