Facilities discharging industrial wastewater to Publicly Owned Treatment Works (POTWs) must be keenly sensitive to changes in the nature and volume of their discharge. Proper planning, notification and interaction with the POTW may mean the difference between the smooth road of evolving business and the bumpy road of enforcement. Unfortunately, all too often, enforcement actions from POTWs include pretreatment violations involving the introduction of a new chemical or establishment of an entirely new process line without requisite notification.
Such an oversight may easily result in multiple violations. Particularly in the case of Significant Industrial Users subject to a Categorical Pretreatment Standard in 40 CFR §§ 405 – 471, even minor alterations to processes have the potential to cause exceedances of categorical limits. Because categorical limits are uniquely customized for particular process types, limits vary dramatically even within industry categories. For instance, within the Textile Mills Point Source Category (40 CFR § 410), a facility in the wool scouring sub-category is subject to a daily maximum BOD5 limit of 10.6 kg, whereas the wool finishing sub-category daily BOD5 limit is 22.4 kg. Subtle variations in processes within industry categories may result in violations of sub-category limits. In addition to violations of effluent limitations, changes in process chemistry or discharge volume may result in procedural violations as well. The General Pretreatment Regulations require any industrial user to “promptly notify the . . . POTW . . . in advance of any substantial change in the volume or character of pollutants in their discharge.” 40 CFR § 403.12(j). Where such notification is not given and the discharge exceeds effluent limitations, multiple violations may be alleged.
Defenses to these types of violations will be difficult to come by. The often used “upset defense” requires the noncompliance to have been “unintentional and temporary” and “beyond the reasonable control of the Industrial User.” 40 CFR § 416(a). Planned process changes are certainly intentional, often long term and well within the control of the Industrial User. The advisable path forward when planning a change in process chemistry or volume is to carefully review current pretreatment permit limits and consider the impact the change will have on the facility’s ability to comply with those limits. Finally, where planned changes to the volume or character of pollutants in the discharge are substantial, proper notification of the POTW is essential to continued compliance.