Washington Administrative Code
Title 173 - Ecology, Department of (See also Titles 197, 317, 372, and 508)
Chapter 173-219 - RECLAIMED WATER
Section 173-219-330 - Performance standards
Reclaimed water performance standards. All Class A and Class B reclaimed water at a minimum must meet the technology-based performance standards listed in Table 1 and Table 2 for the class of reclaimed water generated at the facility. Compliance shall generally be measured at the end of treatment, however, the reclaimed water permit may specify alternative monitoring locations and water quality limits to ensure compliance with performance standards, and any additional use based requirements as listed in Table 3.
Table 1: Minimum Biological Oxidation Performance Standards
| Biological Oxidation | ||
| Parameter1 | Minimum Biological Oxidation Performance Standard | |
| Dissolved Oxygen | Must be measurably present | |
| BOD5 | Monthly Average | Weekly Average |
| 30 mg/L | 45 mg/L | |
| CBOD5 | 25mg/L | 40 mg/L |
| TSS | 30 mg/L | 45 mg/L |
| pH | Minimum | Maximum |
| 6 s.u. | 9 s.u. | |
| pH (Groundwater recharge) | 6.5 s.u. | 8.5 s.u. |
1 The parameter must be measured at the end of the unit process or alternative monitoring location as set in a reclaimed water permit.
Table 2: Class A and B Performance Standards
| Coagulation/Filtration | ||||
| Parameter1 | Class A Reclaimed Water | Class B Reclaimed Water | ||
| Turbidity2 | Monthly Average | Sample Maximum | Monthly Average | Sample Maximum |
| 2 NTU | 5 NTU | Not Applicable | Not Applicable | |
| Membrane Filtration | ||||
| Turbidity2 | Class A Reclaimed Water | Class B Reclaimed Water | ||
| Monthly Average | Sample Maximum | Monthly Average | Sample Maximum | |
| 0.2 NTU | 0.5 NTU | Not Applicable | Not Applicable | |
| Disinfection | ||||
| Total Coliform | Class A Reclaimed Water | Class B Reclaimed Water | ||
| 7-Day Median | Sample Maximum | 7-Day Median | Sample Maximum | |
| 2.2 MPN/100 mL or CFU/100 mL | 23 MPN/mL or CFU/mL | 23 MPN/mL or CFU/mL | 240 MPN/mL or CFU/mL | |
| Virus Removal | See disinfection process standards in WAC 173-219-340 | Not Applicable | Not Applicable | |
| Denitrification3 | ||||
| Class A Reclaimed Water | Class B Reclaimed Water | |||
| Total Nitrogen | Monthly Average | Weekly Average | Monthly Average | Weekly Average |
| 10 mg/L | 15 mg/L | Not Applicable | Not Applicable | |
1 The parameter must be measured at the end of the unit process or alternative monitoring location as set in a reclaimed water permit.
2 Sample maximum for turbidity is the highest value for the day that lasts longer than five minutes.
3 Not applicable for beneficial uses 1-13 listed on Table 3: Use-Based Requirements.
