As used in this chapter, the following definitions shall be supplemental to the definitions given in the sewer ordinance of the city.
A. “POTW (publicly owned treatment works)” means the city’s wastewater treatment plant including any sewers that convey wastewater to the POTW, and excluding pipes, sewers, or other conveyances not connected to the POTW. POTW includes any sewers that convey wastewater to the POTW from persons outside the city who are users of the city’s POTW. If the context so dictates, POTW may refer to the city.
B. “BOD (biochemical oxygen demand)” means the quantity of oxygen utilized in the biochemical oxidation of organic matter under standard laboratory procedure, five days at twenty degrees centigrade expressed in terms of weight and concentration (milligrams per liter (mg/L)).
C. “TSS (total suspended solids)” means solids that either float on the surface of, or are in suspension in waters, sewage or other liquids, and which are removable by laboratory filtering as described in standard methods.
D. “FOG (fat, oil and grease)” means compounds of alcohol or glycerol with fatty acids such as, but not limited to, butter, lard, margarine, vegetable fats and oil, and other related constituents found in wastewater.
E. “User” means any individual, firm, company, association, society, corporation or group, who contributes, or causes or allows the contribution of wastewater into the POTW.
F. “Base strength” means normal untreated domestic wastewater with a maximum yearly average BOD not in excess of two hundred twenty mg/L, a maximum yearly average TSS not in excess of two hundred twenty mg/L, and a maximum yearly average FOG not in excess of two hundred mg/L.
G. “40 CFR” means the latest edition of Title 40 of Code of Federal Regulations.
H. “Standard methods” means the laboratory procedures set forth in the latest edition, at the time of analysis, of Standard Methods for the Examination of Water and Waste-water, as prepared, approved and published jointly by the American Public Health Association, American Water Works Association, and the Water Environment Federation of Methods for Chemical Analysis of Water and Wastes of the U.S. Environmental Protection Agency.
I. “Grab sampling” means a single sample of water collected at a particular time and place which represents the composition of the water only at that time and place.
J. “Composite sampling” means a collection of individual samples obtained at regular intervals, usually every one or two hours during a twenty-four-hour time span. Each individual sample is combined with the others in proportion to the rate of flow when the sample was collected. Equal volume individual samples also may be collected at intervals after a specific volume of flow passes the sampling port or after equal time intervals and still be referred to as composite sample. The resulting mixture (composite sample) forms a representative sample and is analyzed to determine the average conditions during the sampling period. (Ord. 1485-95 § 2(part), 1995).