Analytical Methods

POTWs with approved pretreatment programs may, at their discretion (as authorized by their local ordinances and regulations), require their indirect dischargers to achieve specific minimum levels when performing analyses or may require the use of specific analytical methods to enable the POTW to better characterize contributions into their system. Where a state or the EPA is the pretreatment Control Authority, the specific requirements for analytical methods can be specified in the control mechanism issued to the indirect discharger. The General Pretreatment Program requirements at 40 CFR part 136 and 40 CFR 403.12(g)(5) require that samples be analyzed using the approved methods listed in 40 CFR part 136 (CFR, Part 60, Appendix A Method 9 2017) (CFR, Part 60, Appendix A Method 22 2019). The approved analytical methods for analyzing wastewater samples can be found at 40 CFR part 136 (http://www.ecfr.gov/cgi‐bin).

The EPA Office of Water analytical methods website is (https://www.epa.gov/cwa‐methods).

The industry and POTW and laboratory analyst should consult the current regulations at 40 CFR part 136 as analytical methods may be updated and/or deleted (USEPA 1983). Table 4.4 shows selected analytical methods for corresponding pollutants in water samples.

State Waste Discharge Permit

In the United States, a State Waste Discharge Permit is required for a discharge of treated wastewater to waters of the state which includes surface water and groundwater. A state waste discharge permit is also required for any industrial or commercial operators discharging solid or liquid waste material into sewerage systems operated by municipalities or public entities which in turn discharge to waters of the state (State of Washington in the United States as an example). This permit is issued under authority of Chapter 90.48 RCW (revised code of Washington State) for water pollution control. A state waste discharge permit is valid for a maximum of five years. An applicant for a state waste discharge permit may receive a Temporary State Waste Discharge Permit if the state fails to act upon a complete application for a period of 60 days. A temporary state waste discharge permit is valid for five years or until state issues waste discharge permit. A temporary state waste discharge permit authorizes discharge as requested in the permit application. A facility covered under a temporary state waste discharge permit must reapply at least 60 days prior to expiration of the temporary permit.