D.C. Mun. Regs. tit. 21, § 1511
1511.1 Permitted Industrial Users discharging high strength wastewater into the District's wastewater system shall be assessed a high-strength waste fee, in addition to the normal sewer charges, which are based solely on the volume of wastewater discharged. The purpose of the high-strength waste fee is to defray the extra cost to WASA for treating such wastewater.
1511.2 The high-strength waste fee shall be applied to those permitted discharges whose average daily concentration exceeds one (1) or more of the following limits:
1511.3 High-strength waste fees may be applied to additional constituents for other high strength wastewater based on criteria determined by WASA. Charges shall be computed in a similar manner provided in § 1511.4.
1511.4 The high-strength waste fee shall be computed using the following formula for those constituents exceeding the values specified in § 1511.2:
$$\text{High-strength waste fee} = V \times 8.34 \times [\text{FB (AB-300 or AC-450)} + \text{FS (AS-300)} + \text{FN (AN-40)} + \text{FP (AP-6)}]$$
Where:
V = volume of sewage in millions of gallons discharged by the Industrial User during the billing period.
FB = the cost for treating BOD or COD expressed in dollars/pound.
AB = the average daily concentration of BOD in the sewage discharged expressed in mg/L, or
AC = the average daily concentration of COD in the sewage discharged expressed in mg/L (use the higher value of AB-300 or
AC-450).
FS = the cost for treating TSS expressed in dollars/pound.
AS = the average daily concentration of TSS in the sewage discharged expressed in mg/L.
FN = the cost for treating TKN or TN expressed in dollars/pound.
AN = the average daily concentration of TKN or TN in the sewage discharged expressed in mg/L.
FP = the cost for treating TP expressed in dollars/pound.
AP = the average daily concentration of TP in the sewage discharged expressed in mg/L.
1511.5 The cost for treating each constituent shall be determined by WASA and provided in chapter 1 of this title.1511.6 The volume of sewage from the Industrial User shall be determined based upon either:- (a) Metered or estimated water consumption for the billing period; or
- (b) Metered or estimated wastewater discharge entering the sewer system.1511.7 If estimated flows are used, the procedure for determining the flows shall be submitted by the Industrial User and approved by WASA.1511.8 If metered wastewater discharge to the sewer system is used, the Industrial User shall provide and maintain at their own expense, metering facilities as required to indicate accurately, to the satisfaction of WASA, the volume of discharge to the sewer system.1511.9 Flow data shall be submitted to WASA in a format and content acceptable to WASA and at a frequency specified by WASA.1511.10 If wastewater flow data provided by the Industrial User is not submitted to WASA by the specified date, WASA may calculate the high-strength waste fee using the metered water consumption.1511.11 The average daily concentration of each constituent for each Industrial User shall be determined at least once a year based upon:- (a) All sampling and analysis results from sampling conducted by
WASA for the previous twelve (12) month monitoring period, or as specified by WASA; and
(b) All sampling and analysis results from sampling conducted by the Industrial User for the previous twelve (12) month monitoring period, or as specified by WASA, that WASA determines is characteristic of the overall nature of such discharge; or
(c) Historical records for Industrial Users having similar discharge characteristics.
1511.12 In cases where Industrial Users have discharge pollutant concentrations that fluctuate significantly, WASA may revise the average daily concentration of the constituents based on more frequent sampling and analysis of the discharge.
1511.13 In cases where an Industrial User makes a significant change at their facility to reduce the strength of their wastewater, WASA may revise the average daily concentration of the constituents based on sampling and analysis of the discharge following the change.
1511.14 To request a re-evaluation of the average daily concentration, the Industrial User shall submit a request to WASA containing the following information:
(a) Description of the change; and
(b) Analytical data for the constituent(s) to be re-evaluated consisting of weekly sampling for at least four (4) weeks, with the day of sampling to be rotated each week, or four (4) consecutive days of sampling within one (1) week that are representative of the discharge following the change. Samples shall be collected as twenty-four (24) hour time-proportional or flow-proportional composite samples, unless WASA approves otherwise. Copies of all laboratory reports and chain of custody documentation shall be included in the submittal.
1511.15 An Industrial User may challenge the high-strength waste fees on a sanitary sewer service bill or appeal the General Managers final decision in accordance with the procedures set for in chapter 4 of this title.
SOURCE: Final Rulemaking published at 33 DCR 6194, 6202 (October 10, 1986); as amended by Final Rulemaking published at 47 DCR 2948 (April 28, 2000); as amended by Notice of Final Rulemaking published at 59 DCR 1021, 1067 (February 10, 2012).