Pretreatment Program


The Clean Water Act in 1972 prompted the States to adopt programs to monitor the cities in their jurisdiction and hold them accountable for the quality of water discharged to streams and rivers.  This includes the wastes that factories and commercial businesses produce.

The States in turn have pushed those requirements down to the local level.  The Pretreatment Program is a federally-mandated, locally-enforced program that regulates discharges by Industrial Users (IUs) in a wastewater system.  In addition, any industry that discharges any water (either stormwater or wastewater) directly to a watercourse in the Commonwealth of Kentucky must obtain a Kentucky Pollutant Discharge Elimination System (KPDES) permit.

Currently there are seventeen (17) significant industrial users (SIUs) regulated by the City of Henderson Pretreatment Program.  Thirteen (13) of these discharge to the North WWTP and four (4) discharge to the South WWTP.  Some are large entities and some are small family businesses.

Pretreatment is the term used to describe what industries may have to do to their waste stream prior to discharge to the City’s collection system and POTW (Publicly Owned Treatment Works).  It is often easier to treat a waste at its source than it is after it has traveled down the line or entered the wastewater plant.  Pretreatment requirements also help to insure that industrial users pay a fair portion of the costs for their particular contribution to the overall waste stream.

The following criteria will cause an IU to be included in a local Program:

  • An industry categorized as a Significant Industrial User (SIU) or a Categorical Industrial Users (CIU), as specified in 40 CFR (Code of Federal Regulations) 403.6 and Parts 405-471.
  • An IU discharging 25,000 gallons per day or more of process wastewater, noncontact cooling water, or boiler blowdown.
  • An IU which contributes 5% or more of the dry-weather hydraulic loading or capacity of POTW.
  • Any IU having reasonable potential to adversely affect the POTW, or who violates any standard or requirement.

The main function of the Pretreatment Program is to protect the POTW by consistently tracking the output of wastewater from Industrial Users.  There are two (2) regulations that govern Pretreatment Programs: 40 CFR, Parts 122 and 403.

 The Local Program

The Industries in our local program are inspected and sampled regularly by HWU personnel.  They are also required to submit Self-Monitoring analyses on their waste streams to the HWU Pretreatment Program Coordinator each year as specified in their Discharge Permit.  This is done to help monitor the consistency of the industry’s wastewater discharge and keep ‘running data’ on the quality of their discharge from their laboratory as well as the HWU’s laboratory.  For the sake of neutrality, the HWU contracts an outside laboratory to perform the monitoring on the Industrial Users in the Pretreatment Program.

The local program also establishes Local Limits which are discharge limitations that control the quantity and quality of the industrial process wastewater that is discharged to the HWU sanitary sewer system.  A complete description of the process for setting these Local Limits is available for the North and South wastewater systems.

To assure fairness and equal treatment in the event of a violation, HWU has created an Enforcement Response Plan (ERP) that details steps of enforcement in solving a problem with an industry.  The ERP contains sample forms for enforcement actions, and includes a chart of progressive discipline steps that will be taken in the event of violations of any standard.  Regulations also give the city the ability to collect charges for violations of certain parameters that the Industry might exceed during a monitoring event.  These are referred to as surcharges.  This allows cities to re-coup treatment costs for organics that exceed the permit limit of the Industrial User, yet are treatable at the Wastewater Plant.  A copy of the ERP is available for review here.

The Kentucky Division of Water also requires three (3) reports per year from the Henderson Water Utility that show the status of all the Industries in the Pretreatment Program, as well as an annual laboratory scan on the Wastewater Treatment Plants influent, effluent, and bio-solids.  HWU has many reporting requirements from the State just as the Industries have them to the Henderson Water Utility.  Each entity is accountable for the quality of their wastewater stream.

These are just a few facts about our program.  There is much more to know about the federal Pretreatment Program.  If you want to know more about its role and purpose, you can reach the Pretreatment Coordinator at (270) 826-2824 or on our website at

Pretreatment Program Documents

The Clean Water Act (1972) (U.S. EPA Summary)

Oil & Grease Control Program Permit Application (Revised 09-14-2017)

Local Limits Evaluation for North WWTP (March 2014)

Local Limits Evaluation for South WWTP (March 2014)

Enforcement Response Plan (ERP) for Industrial Users (Adopted February 12, 2013)

HWU Wastewater Application – Introduction

HWU Wastewater Application

Slug Control Questionnaire

Grease Management Brochure and Information

Local Limits Tables (North System and South System) (Effective 07/01/2014)

Public Notice – Ordinance 20-14 (Ordinance adopting new Sewer Use Ordinance)

Current Surcharge Rates (See “Table E” on Page 3 of this document)

Calculating Total Toxic Organics (TTO)

Septic Hauler Wastewater Application

Pretreatment Resources