No person shall discharge or cause to be discharged the following described prohibited substances, materials, waters or wastes if it appears likely, in the opinion of the town manager, that such wastes can harm either the sewers, sewage treatment process or equipment, can have an adverse effect on the receiving stream, or can otherwise endanger life, limb, public property or constitute a nuisance. In forming his opinion as to the acceptability of these wastes, the manager will give consideration to such factors as quantities of subject wastes in relation to flows and velocities in the sewers, materials of construction of the sewers, nature of the sewage treatment process, capital of the sewage treatment plant, degree of treatability of wastes in the sewage treatment plant, and other pertinent factors. The substances prohibited are as follows:
(1) Any liquid or vapor having a temperature higher than 104 degrees Fahrenheit (40 degrees Celsius).
(2) Any wastes or waters containing fats, wax, grease or oil in excess of 100 mg/L (per NCDENR), as determined by results of the Freon extractable test, and the reasonable interpretation of test results, and/or auxiliary tests, to exclude from the measurement values which do not represent fats, wax, grease and oil.
(3) Any garbage other than ground residential garbage from residential kitchen sinks.
(4) Any acidic or alkaline wastewaters having pH values outside the range of 5.0 to 10.0.
(5) Heavy metals and toxic, refractory or organic chemicals in concentrations or quantities sufficient to limit treatment plant capability or efficiency, to adversely affect effluent quality by their presence or effects, or to limit the means of disposal or utilization of treatment plant sludge by their presence. The manager may issue lists of prohibited metals and toxic chemicals and guidelines and criteria for limiting their acceptance as required for operation of the treatment system.
(6) Any radioactive wastes or isotopes of such half-life or concentration as may exceed public safety limits or cause the plant effluent or sludge to exceed any applicable state or federal regulations.
(7) Any materials which exert or cause:
a. Unusual oxygen demand or chlorine demand in such amounts as to constitute a significant load or an operating problem.
b. Excessive discoloration of treatment plant effluent.
c. Unusual odors in the treatment plant effluent or unusual odors in the sewerage system.
(Code 1989, § 51.17)