Author: Paula Boyle

Paula is an experienced engineer whose career has encompassed many environmental projects including industrial pretreatment projects. She has over 30 years of practical knowledge in industrial and commercial pretreatment systems and compliance monitoring methodologies for USEPA and state requirements as part of NPDES permits. She is experienced with assisting municipalities with administering all aspects of Industrial Pretreatment Programs including Headwork Loadings Analysis and Sewer Use Ordinance updates. Paula’s experience with the coordination of regulatory and funding programs ensures that projects follow the federal and state regulations and guidelines while maximizing attainable funds at the planning, design and construction phases.

The Importance of Local Limits for Our Wastewater Systems

Clean water is essential to our environment and quality of life. The National Pollutant Discharge Elimination System (NPDES) includes National Pretreatment Program elements developed by USEPA to control pollutant discharges from Publicly Owned Treatment Works (POTWs) into the nation’s waterways. In other words, the National Pretreatment Program is an important program which includes specific regulatory tools to keep our water clean – all over the country.

Issues Pretreatment Programs Help Prevent

POTWs must ensure compliance with federal pretreatment standards by regulating non-domestic (industrial and commercial) users, such as pharmaceutical manufacturers, metal finishers and breweries, to name a few.  Local limits are intended to keep POTWs in compliance with NPDES permits as well as to prevent operational issues at wastewater treatment facilities and within the wastewater collection system. Pollutants incompatible with treatment works can cause major disruptions to the collection system and treatment works as well as contribute to permit violations.

Essentially, local limits regulate the type and quantity of pollutants, discharged to the POTW by non-domestic users, that could cause pass-through, interference or sludge contamination. Local limits are part of an Industrial Pretreatment Program’s (IPP) regulatory framework and are generally published in a local Sewer Use Ordinance. There are many USEPA-approved IPPs throughout Region 1 with varying numbers and types of industrial users and site-specific local limits.

POTWS should Develop Technically Based Local Limits

POTWs should develop technically based local limits to protect operations, ensure compliance with state and federal environmental requirements and protect the health and safety of workers, using site-specific conditions including the following factors:

  • The POTW’s history of compliance with its NPDES permit
  • The POTW’s efficiency in treating the wastewater
  • The water quality of the waterbody receiving the treated effluent
  • Sewage sludge disposal regulations
  • Worker health and safety concerns

When Local Limits Should be Developed

Local limits should be developed for approved IPPs and nonapproved programs if pollutants from non-domestic sources result in interference, pass-through or sludge contamination at the POTW. It is increasingly important to protect the sludge disposal options available to POTWs considering the federal and state PFAS (per- and poly-fluoroalkyl substances) sludge disposal standards due to be issued in the very near future. Having technically based local limits in place to protect the POTW will assist with the process of assessing the need for potential PFAS local limits as well.

When Local Limits Should be Updated

A requirement of the NPDES permit is to conduct a reassessment of technically based local limits, typically every five years at the time of an NPDES permit renewal. Local limits should also be updated when there is an NPDES permit revision, there is an increase or decrease in the number or type of Significant Industrial Users (SIUs), the POTW is upgraded or there is a change in the NPDES permitted flow, or the POTW’s pollutant removal efficiencies.

In Relation to PFAS

Local limits are critically important in view of the emergence of new contaminants and increasing lower detection levels for contaminants. Several New England POTWs have recently received new NPDES permits that include influent, treated effluent and dewatered sludge monitoring for PFAS compounds. Many other POTWs will soon notice requirements for PFAS monitoring in their newly issued NDPES permits. In addition, monitoring for PFAS at expected known PFAS source facilities are now included in recently issued NPDES permits.  Source facilities may include the following:

  • Commercial car washes
  • Platers/metal finishers
  • Paper & packaging manufacturers
  • Tanneries & leather/fabric/carpet treaters
  • Manufacturers of parts with polytetrafluoroethylene (PFTE) or Teflon type coatings (i.e., bearings)
  • Landfill leachate
  • Centralized waste treaters
  • Contaminated sites

The final USEPA requirements for wastewater and sludge monitoring using multi-laboratory validation and reporting is still in process, but the data gathered over the next five years across New England, and nationally, will be used to further define the requirements for controlling the disposal of PFAS into the environment.

Hoyle Tanner’s Experts are Ready to Help

Hoyle Tanner continues to meet the needs of the industry with engineering professionals whose experience includes understanding NPDES permit requirements, developing and reassessing local limits, including public outreach sessions, to provide information to industrial users to understand the impact local limits may have on their businesses and to give wastewater treatment plant operators the tools necessary to understand and control their wastewater treatment and sludge disposal processes. Want to learn more? Contact me!

The Need for Industrial Pretreatment Programs (IPP)

picture of bewery vats

Whether it’s a brewery, paper mill, food or chemical plant in your community, these businesses almost always produce industrial wastewater. As such, there is a need for wastewater management generated from these, and many other, industrial activities discharging to a Publicly Owned Treatment Works (POTW). Managing industrial wastewater can be accomplished through a well-run Industrial Pretreatment Program (IPP). In addition, with the emergence of new contaminants that might not be compatible with POTWs, an IPP facilitates the regulatory framework to determine the origins of such contaminants.

National IPP: Setting the Standards

In 1972, US Congress passed the Federal Water Pollution Control Act, known as the Clean Water Act (CWA), to restore and maintain the nation’s water quality. The Act’s goals were to eliminate the introduction of pollutants into the nation’s navigable waters to achieve “fishable and swimmable” water quality levels. The CWA’s National Pollutant Discharge Elimination System (NPDES) Permit Program is one key component established to accomplish these goals. The NPDES Permit Program generally requires that direct dischargers to a waterbody obtain an NPDES Permit.

In addition to addressing direct discharges to the nation’s waterways, the National Pretreatment Program is a regulatory program for pollutants that are discharged into a POTW, otherwise known as indirect discharges. This program requires industrial and commercial facilities to obtain permits (or use other control measures) to discharge their wastewater to a POTW. Certain discharges by these users may pass through or interfere with the operations of a POTW, leading to a direct discharge of untreated wastewater into rivers, lakes, and other water bodies.

The goals of the National Pretreatment Program as stated in 40 Code of Federal Regulations (CFR) Part 403.2 are as follows:

  • To prevent the introduction of pollutants into a POTW that will interfere with the operation of the POTW, including interference with its use or disposal of sludge
  • To prevent the introduction of pollutants into a POTW that will pass through the treatment works otherwise be incompatible with such works
  • To improve opportunities to recycle municipal and industrial wastewater and sludges

To accomplish these goals, the National Pretreatment Program requires all large POTWs (those with design flows greater than 5 million gallons per day) and small POTWs that accept wastewater from industrial users that could affect POTWs to establish a local pretreatment program. Local pretreatment programs must enforce national pretreatment standards and requirements, as well as more stringent local requirements necessary to protect the site-specific conditions of the POTW. For example, industrial discharges from a large brewery with organic loadings much greater than typical domestic loadings may not negatively impact a large POTW but might cause major interference or pass-through at a very small POTW not designed to properly treat such organic loads.

Identifying and understanding a POTW’s Significant Industrial User’s (SIU’s) wastewater discharges is an important component of an IPP since SIUs have the ability to adversely affect the POTW.

Implementing IPP on the Local Level

Once the determination has been made that a POTW needs a local pretreatment program, six minimum elements must be included in a pretreatment program submission for review and approval by the USEPA, the state or both, depending on state statute.

  1. Legal Authority – A POTW must have the legal authority which authorizes the POTW to apply and enforce any pretreatment requirement. This authority is derived from state law.
  2. Procedures – A POTW must develop and implement procedures to ensure compliance with pretreatment requirements which include:
    • Identifying all Industrial Users (IUs) subject to the pretreatment program
    • Identify the characteristic of pollutants contributed by IUs
    • Notify users of applicable pretreatment standards and requirements
    • Receive and analyze reports from IUs
    • Sample and analyze IU discharges
    • Evaluate the need for an IU slug control plan
    • Investigate instances of IU non-compliance
    • Comply with public participation requirements
  3. Funding – A POTW must have sufficient resources and qualified personnel to carry out the procedures included in the approved pretreatment program.
  4. Local Limits – A POTW must develop local limits developed for pollutants that could cause interference, pass through or sludge contamination or worker health and safety problems.
  5. Enforcement Response Plan (ERP) – A POTW must develop and implement an ERP containing detailed procedures indicating how the POTW will investigate and respond to IU non-compliance instances.
  6. List of SIUs – A POTW must prepare, update and submit to the approval authority a list of all SIUs.

These elements are important for managing a well-run local pretreatment program and developing good working relationships with IUs. As new contaminants continue to emerge that are not compatible with POTWs, pretreatment programs will be useful to identify sources of new contaminants that may potentially cause issues with POTW effluent water quality or sludge disposal practices. A pretreatment program must be adaptable, and any necessary modifications to local pretreatment programs to address new contaminants must be conducted expeditiously.

Our Experience with IPP & Water Treatment

Hoyle, Tanner’s Northeast Municipal Engineering Services Group employs 20 engineers whose primary focus is water quality engineering – wastewater, stormwater and drinking water. industrial inspections, writing annual reports or providing technical expertise relative to enforcement actions. Our team has the experience to provide pretreatment program resources and immediate expertise.

Our depth and breadth of pretreatment program experience includes: identifying IUs to be included in an IPP, writing industrial user permits, evaluating the need for updating technically-based local limits, and updating Sewer User Ordinances and ERPs.

For more information, please visit our website at: or contact Senior Engineers Paula Boyle or Heidi Marshall.