Austin City Code § 15-10-121 SURCHARGE FOR EXTRA STRENGTH WASTEWATER.
§ 15-10-121 - SURCHARGE FOR EXTRA STRENGTH WASTEWATER.
(A) A person discharging to the POTW either extra strength wastewater or wastewater containing other pollutants for which unit charges have been developed in accordance with Subsection (M) of this section shall pay a monthly surcharge in addition to a usual monthly sewer service charge.
(B) Except as provided in Subsection (M) of this section, the director shall calculate the surcharge under this section using cost factors based on the capital and operating cost of wastewater facilities necessary to treat extra strength wastewater to reduce excessive biochemical oxygen demand, chemical oxygen demand, and suspended solids.
(C) Except as provided in Subsection (M) of this section, the director shall compute the surcharge based on either the chemical oxygen demand or the biochemical oxygen demand category formulas set out in this section.
(D) Abbreviations and numeric values in this section mean:
(1) S: surcharge in dollars that will appear on the customer's monthly bills;
(2) V: wastewater billed in millions of gallons during the billing period;
(3) 8.34: pounds per gallon of water;
(4) A: unit charge in dollars per pound of biochemical oxygen demand;
(5) BOD: biochemical oxygen demand strength in milligrams per liter by weight;
(6) 200 in the biochemical oxygen demand calculation in the biochemical oxygen demand formula means normal biochemical oxygen demand strength in milligrams per liter by weight;
(7) B: unit charge in dollars per pound for suspended solids;
(8) SS: suspended solids concentration in milligrams per liter by weight;
(9) 200 in the suspended solids calculation in the biochemical oxygen demand and chemical oxygen demand formulas means normal suspended solids concentration in milligrams per liter by weight;
(10) C: unit charge in dollars per pound for chemical oxygen demand;
(11) COD: chemical oxygen demand strength in milligrams per liter by weight; and
(12) 450: Normal chemical oxygen demand strength in milligrams per liter by weight.
(E) The director shall use the following biochemical oxygen demand category formula to derive a surcharge for extra strength wastewater having a chemical oxygen demand concentration of less than 2.25 times that of the biochemical oxygen demand concentration: S = V × 8.34 (A [BOD - 200] + B [SS - 200]).
(F) The director shall use the following chemical oxygen demand category formula to derive a surcharge for extra strength wastewater having a chemical oxygen demand concentration of 2.25 or more times that of the biochemical oxygen demand concentration: S = V × 8.34 (C [COD - 450] + B [SS - 200]).
(G) Except as provided in Subsection (M) of this section, the director may not assess a surcharge for one or more categories if the strength or concentration for biochemical oxygen demand, suspended solids or chemical oxygen demand is lower than or equal to the normal strength wastewater for that category.
(H) The director may periodically reevaluate a unit charge based on flow rate, biochemical oxygen demand, chemical oxygen demand, and suspended solids and adjust a surcharge to reflect an increase or decrease in wastewater treatment and other applicable costs.
(I) The director may assess a surcharge against a person who discharges extra strength wastewater to the POTW based on the person's site-specific wastewater discharge quality and quantity data, or a surcharge classification system.
(J) A person discharging wastewater to the POTW must notify the director of major changes in operation that may affect the quantity or quality of wastewater discharged. If the person does not notify the director of a change that results in a lower surcharge, the director shall base the surcharge on the data available to the director at the time the surcharge is billed.
(K) A person who discharges waste with a concentration of one or more categories of biochemical oxygen demand, chemical oxygen demand or suspended solids lower than or equal to normal strength wastewater is not entitled to credit for the total surcharge assessed by the director.
(L) The director may periodically reevaluate flow rate, biochemical oxygen demand, chemical oxygen demand or suspended solids data based on site-specific discharge data or a classification system and adjust a specific user's surcharge to reflect any change in the discharge.
(M) The director may develop other unit charges and calculate a surcharge for wastewater using flow rates and strengths or concentrations for other pollutants discharged to recover wastewater treatment and other applicable costs as deemed necessary and appropriate.
(N) Payment of any surcharge under this section does not constitute a waiver of any of the prohibited discharge standards in this chapter, nor does it relieve any person from the obligation to meet all pretreatment requirements in this chapter.
Source: 1992 Code Section 18-2-121; Ord. 031204-14; Ord. 031211-11; Ord. No. 20200729-002, Pt. 23, 8-10-20.