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Definitions of Classes and Subclasses

An operator must hold the proper classification and subclassification certification to make a process control at a water or wastewater treatment system. DEP assigns a system classification based on the size of the drinking water or wastewater treatment system. A certified operator must hold a certification class that is equal to or greater than the size of the system to make process control decisions for that system. The board awards certification class based upon an operator’s experience. Special classifications are also available for small water systems and non-treatment parts of systems (i.e. collection and distribution systems). The following classifications are:

Wastewater Classes

Class A – Greater than 5 MGD 
Class B – Greater than 1 MGD but less than or equal to 5 MGD 
Class C – Greater than 100,000 gpd but less than or equal to 1 MGD 
Class D – Less than or equal to 100,000 gpd 
Class E – Satellite collection system with a pump station (Is combined with wastewater subclassification 4)

Water Classes

Class A – Greater than 5 MGD 
Class B – Greater than 1 MGD but less than or equal to 5 MGD 
Class C – Greater than 100,000 gpd but less than or equal to 1 MGD 
Class D – Less than or equal to 100,000 gpd 
Class E – Distribution and Consecutive Water Systems

Class Dc – must meet all of the following conditions:
  • system serves less than 500 individuals or has no more than 150 connections, whichever is less;
  • the source of water for the system is exclusively groundwater,
  • requires only disinfection, and
  • is not in violation of DEP rules and regulations.
Class Dn – meets all the conditions of Dc and does not have any disinfection.

DEP assigns treatment subclassifications to drinking water/wastewater treatment systems or laboratory supervisors. These treatment subclassifications identify the type of physical, biological, or chemical methods used by the treatment plant or the role performed by a lab supervisor. Water systems may and usually do have more than one treatment subclassification. A certified operator must hold a certification subclass for those treatment methods to make process control decisions for that system. The Board awards certification subclassification based upon an operator’s education, examination score, and experience. The following subclassifications are:

Wastewater Subclasses

Subclassification 1 – Activated Sludge – Treatment technology such as extended aeration, sequential batch reactors, contact stabilization, conventional, step fed, or oxidation ditch.

Subclassification 2 – Fixed film treatment – Treatment technology such as trickling filters and rotating biological contactors.

Subclassification 3 – Treatment ponds and lagoons – Treatment technology that uses aerated, anaerobic, facultative process, or wetlands to treat wastewater.

Subclassification 4 – Single entity collection system – A wastewater collection system where the collection system relies on treatment from a wastewater treatment system owned by the owner of the collection system.

Subclassification 5 - Laboratory Supervisor - An individual having 2 years of hands-on analytical testing experience, knowledge, skills and abilities necessary to supervise laboratory procedures and the reporting of analytical data for an environmental laboratory operated by a wastewater system in accordance with industry, State and Federal standards.  An operator must already be certified in wastewater treatment with Class A, B, C, or D to add this subclassification.

Water Subclasses

Subclassification 1 – Conventional filtration – For drinking water, a series of processes for the purpose of substantial particulate removal consisting of coagulation, flocculation, sedimentation, and filtration.

Subclassification 2 – Direct filtration – For drinking water, a series of processes for the purpose of substantial particulate removal consisting of coagulation and filtration. The term normally includes flocculation after coagulation, but does not include sedimentation.

Subclassification 3 – Diatomaceous earth filtration – For drinking water, a process for the purpose of substantial particulate removal, in which a pre-coat cake of diatomaceous earth filter media is deposited on a support membrane (septum) and, while the water is filtered by passing through the cake on the septum, additional filter media, known as body feed, is continuously added to the feed water, to maintain the permeability of the filter cake.

Subclassification 4 – Slow sand filtration – For drinking water, a process for the purpose of substantial particulate removal by physical and biological mechanisms during the passage of raw water through a bed of sand at low velocity, generally less than 0.4 meters per hour.

Subclassification 5 – Cartridge or bag filtration – For drinking water, a process for the purpose of substantial particulate removal by straining with bag or cartridge filters manufactured of various materials and pore sizes.

Subclassification 6 – Membrane filtration – For drinking water, a process that uses a thin film that acts as a selective barrier (semi-permeable) to the transport of matter to remove contaminants from water and includes such processes as electrodialysis, reverse osmosis, nanofiltration, ultrafiltration, microfiltration, or other similar technologies.

Subclassification 7 – Corrosion control and sequestering – A water treatment process designed to mitigate the adverse effects of corrosion in drinking water.

Subclassification 8 – Chemical addition – A water treatment process designed to improve the quality of the water being treated through the addition of chemicals such as lime, soda ash, caustic soda, and permanganate.

Subclassification 9 – Ion exchange and green sand – A water treatment process such as greensand filtration, ion exchange, or activated alumina designed to improve the quality of water being treated by the removal of inorganic constituents.

Subclassification 10 – Aeration and Activated Carbon Adsorption:
  • Aeration – A water treatment process designed to improve the quality of water being treated by introducing air or oxygen into water to remove undesirable dissolved gases, to remove volatile organic compounds or to oxidize inorganic compounds so they can be removed as particulates.
  • Activated carbon – A water treatment process designed to improve the quality of water being treated by using activated granular or powdered carbon to remove specific organic chemical compounds by adsorption.
Subclassification 11 – Gaseous chlorination disinfection – A water treatment process designed to inactivate pathogenic organisms from water being treated utilizing gaseous chlorine.

Subclassification 12 – Non-gaseous chemical disinfection - A water treatment process designed to inactivate pathogenic organisms from water being treated utilizing non-gaseous chemical elements or compounds.

Subclassification 13 – Ultraviolet disinfection – A water treatment process that inactivates pathogenic organisms using light with a wavelength range of 4000 to 40 angstroms.

Subclassification 14 – Ozonation – The water treatment process designed to inactivate pathogenic organisms from water being treated utilizing ozone.

Subclassification 15 – Laboratory Supervisor – An individual having 2 years of hands-on analytical testing, knowledge, skills and abilities necessary to supervise laboratory procedures and the reporting of analytical data for an environmental laboratory operated by a drinking water system in accordance with industry, State and Federal standards.  An operator must already be certified in drinking water treatment Class A, B, C, or D to add this subclassification.