Dischargers of industrial wastewater face a complex and nuanced set of federal, state, and local regulations aimed at protecting the water bodies into which they discharge. Industries discharging to local Publicly Owned Treatment Works (POTWs) are often required to obtain an Industrial Pretreatment Permit. This permitting process can be difficult to navigate, but planning and proper analysis of your facility and applicable regulations can help make it tolerable. Below are five important questions every facility should answer before applying for a pretreatment permit.
Where do you fit?
Federal regulations establish uniform national standards applicable to specific industrial categories for pretreatment of wastewater. These effluent limitations -- called Categorical Pretreatment Standards – are technology-based and will be included in your Pretreatment Permit. Each Categorical Pretreatment Standard is intended to represent the greatest pollutant reductions economically achievable for an industry. There are 58 categories, regulating everything from the dairy industry to steel manufacturing. Within each industry category are subcategories.
It’s important for you to determine precisely what category and subcategory apply to your facility. Subcategories are often very similar in scope to another subcategory, but contain dramatically different limits. For instance, within the Textile Manufacturing category, subcategories of Wool Scouring and Wool Finishing have significantly different daily maximum BOD limits (10.65 kg and 22.4 kg respectively). Even subtle variations in the type of business conducted can result in much different permit limits. Be diligent in ensuring your application specifies the correct category and subcategory and in ensuring the permitting authority doesn’t mistakenly classify your facility as something it is not.
Are you fundamentally different?
Even if an applicant fits squarely into a Categorical Pretreatment Standard, if it can show the facility and its discharge have factors that are fundamentally different from those considered by EPA when developing the standard, the applicant may be eligible for a variance from those standards. For example, if the nature of the pollutants in the discharge or the volume of the discharge is uncharacteristic of the industrial category, an applicant may apply for a fundamentally different factor variance. Also, if the facility has unique treatment technologies not typically used in the industry, a variance may be possible.
Are you a Significant Industrial User?
Many sewer use ordinances require a pretreatment permit only if the applicant is considered a “Significant Industrial User” (SIU). If the applicant will discharge below a certain threshold volume of wastewater (typically 25,000 gallons/day) or contribute less than a certain percentage capacity of the treatment plant (typically 5%), it may not be an SIU. In these instances, many POTWs will accept wastewater from a facility under a less formal arrangement, such as a Letter of Acceptance. An important distinction here is that all applicants covered by a federal Categorical Pretreatment Standard are automatically considered SIUs.
Are you eligible for removal credits?
Another potential variance from strict Categorical Pretreatment Standards exists for facilities discharging to a POTW where the POTW has technologies already in place to remove the type of pollutant found in the facility’s discharge. This variance is called a removal credit. If the POTW can achieve consistent removal of the pollutant and if granting the credit would not cause a violation of its own permit, the POTW may give a facility a removal credit for as much as the POTW’s consistent removal rate of the pollutant. This variance could potentially save a facility significant expense it would otherwise incur in pretreatment costs.
Does the POTW have a full understanding of your discharge?
It is important the POTW has a complete and accurate understanding of an applicant’s processes and waste streams. Most POTW’s have detailed permit application forms, where vital information regarding a facility’s discharge must be provided. The application typically contains a detailed description of the facility’s manufacturing activities, along with a list of raw materials and process chemicals used, as well as the products produced. Full disclosure in this portion of the application ensures the POTW can precisely anticipate the nature of pollutants in the discharge. The application also typically contains operational characteristics, such as whether the facility discharges continuously or in batches, and whether there are seasonal variations or scheduled shutdowns. This information ensures the POTW can anticipate the correct volume of wastewater from the facility. Knowing the nature of the pollutants in a facility’s discharge and the expected volume of wastewater helps POTWs plan for treatment and ensures there are no surprises.
By asking and answering these questions early in the permitting process, you can avoid receiving an unreasonable permit and mitigate the risk of unexpected violations down the road.