For those of you following along, I update my blog on a monthly basis and discuss various aspects of Kentucky’s Pretreatment Program.   You can see previous entries here.  In this installment, I will discuss types of Industrial Users subject to Pretreatment Standards and Limits.

Significant Industrial User (SIU) is defined as any of the following:

  • An Industrial User (IU) subject to federal categorical pretreatment standards-known as categorical industrial user;
  • An IU that discharges an average of 25,000 gallons per day or more of process wastewater to the POTW;
  • An IU that contributes a process waste stream which makes up 5% or more of the average dry-weather hydraulic capacity of the wastewater treatment plant;
  • An IU which is designated by the city on the basis that the industrial user has a reasonable potential for adversely affecting the operation of the collection system or treatment plant, or violating any pretreatment requirement.

Categorical Industrial User (CIU) is defined as:

  • A user who has a facility where an industrial activity is performed and is regulated by one or more federal regulation (40 CFR Parts 401-471);
  • A user who discharges process wastewater to a treatment plant; or
  • A user who performs a categorical activity that is assigned pretreatment limitations, reporting requirements or both.

Non-Significant Categorical Industrial User (NSCIU) is defined as:

  • A Categorical Industrial User who never discharges more than 100 gpd of total categorical wastewater and CIU meets all the following conditions
    • An IU who has consistently complied with all applicable categorical pretreatment standards and requirements;
    • An IU who annually submits the certification statement as required under 403.12(q);
    • A User that never discharges any untreated concentrated wastewater.

Please note that designation as an NSCIU results in reduced reporting requirements for the NSCIU and reduced oversight requirements for the POTW. It does not in any way, relieve the industry of the need to comply with the categorical pretreatment standards.

In my next blog I will talk about the POTW Pretreatment Program.

If you have any questions, please contact me at shrivani@smithmanage.com

Source: U.S. EPA Introduction to the National Pretreatment Program, 2011.