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Preventing Grease Discharges Into Sewers

Guidelines for New York City Businesses

A thriving business community is vital to New York City and its neighborhoods. A healthy economy benefits every New Yorker. But when businesses discharge grease into the sewers, it can cause sanitary sewer overflows and interfere with the City’s sewage treatment operations. It also violates New York City’s Sewer Use Regulations and carries monetary penalties of up to $10,000 per violation. In many cases, the law requires that the polluters appear in court every time a fine is issued.

The New York City Department of Environmental Protection (DEP) is responsible for maintaining the City’s sewage system—6,000 miles of sewers and 14 wastewater treatment plants that process about 1.3 billion gallons of sewage per day—and for enforcing the sewer use regulations. Sewer back-ups are a major sewer system problem that damages property and affects public health. In some areas, back-ups are frequently caused by grease clogging the local sewers. To address this problem, DEP is helping businesses comply with the City’s sewer use regulations, which also include requirements concerning the proper sizing, installation, and maintenance of grease interceptors. DEP is educating not only restaurant owners but also operators of nursing homes, fruit and vegetable stands, laundries, and dry cleaners, among others, to keep grease and other materials and chemicals out of the sewer system.

Food Service Establishments (FSEs) are a significant source of fats, oil and grease (FOG) because of the amount of grease used in cooking. The New York City Commercial FOG Program was developed to assist restaurants and other FSEs with proper handling and disposal of their FOG. Through implementation of Best Management Practices (BMPs), these establishments should be able to significantly reduce the amount of FOG that goes down their drains. This will minimize back-ups and help business owners comply with the City’s requirements. Please note that Food Waste Disposers are not allowed for commercial establishments in New York City.

To work effectively, sewer systems need to be properly maintained, from the drain to the treatment plant. If wastes are disposed of correctly, the City’s sewer system can handle them without any problem. Grease is an example of a waste that the sewer system cannot handle, and therefore should not be put down the drain. The City needs businesses and individuals to do their part to maintain the system because repeated repairs are disruptive to residences and businesses alike. Furthermore, proper disposal by commercial establishments is required by law.

The following brochure, Preventing Grease Discharges Into Sewers, provides general program information on:

  • The problem of FOG in the sewers
  • FOG impacting businesses, the City, and the environment
  • How grease interceptors work and how to maintain/clean them
  • How the DEP enforces the Sewer Use Regulations

The New York City Best Management Practices (BMPS) For Non-Residential Direct and Indirect Dischargers of Grease to the Public Sewer System is an excerpt from Title 15 of the Rules of the City of New York:

The following signs, which can be posted above sinks, can make FOG reduction efforts more visible to employees:

The following, mulitlingual posters can be posted above sinks and floor drains to remind employees not to pour grease into drains:

Sewer Regulations Concerning Grease

To ensure the proper disposal of animal fats and vegetable oils, and to prevent sewage back-ups, the City requires grease-generating establishments to correctly install, operate and maintain properly sized and designed grease interceptors. These grease interceptors must be routinely cleaned to ensure proper operation. (For more information see NYCDEP Sewer Use Regulations, 15 RCNY Chapter 19.)

On November 9, 1998, the City amended the Sewer Use Regulations. These amendments clarify existing requirements and provide for self-certification of grease interceptors by a NYS licensed Professional Engineer or Registered Architect. Self-certification relieves regulated establishments from a lengthy departmental review process.

How Grease Interceptors Work

Every business that disposes of grease, fats or oil (including but not limited to restaurants, cafeterias, clubs, butcher shops, slaughterhouses, fish markets, supermarket food processing areas and delicatessens), should have a grease interceptor to prevent these materials from entering and clogging sewer lines.

Grease Interceptors

This equipment works by separating the grease and oils from wastewater. Greasy wastewater entering the interceptor passes through a vented flow control fitting that regulates the flow of the wastewater. The wastewater then passes over a series of separator baffles, or regulating devices within the interceptor, that separates grease, fat and oil. The grease then floats to the top of the interceptor and accumulates until manually removed. The wastewater continues to flow through the interceptor, into a discharge pipe, and then to the City’s sewer system.

Installing and Maintaining Your Grease Interceptor

If a grease interceptor is not properly installed or maintained it will not do its job! For your own assurance, DEP requires that only licensed plumbers install grease interceptors. These interceptors must be the proper size to work correctly. A licensed plumber can determine the correct size. Plumbers and business owners may also write to DEP’s Bureau of Wastewater Treatment, Compliance Engineering Section, for technical assistance.

Every interceptor should be cleaned as frequently as necessary to avoid exceeding its rated capacity. To clean, remove the cover of the interceptor and scoop out any grease and/or oil that has collected on top. Grease and oil can be recycled, and should be collected by a fat renderer or other grease recycling company. For a list of NYC BIC licensed haulers please click here.

Enforcing Regulations

DEP enforces the City’s sewer use regulations and may fine businesses that are not in compliance. DEP routinely sends inspectors to businesses to check interceptors and make sure they are correctly sized, properly installed, maintained, and operating effectively. If a business has an interceptor that is too small, inspectors will order the owner or operator to install the proper unit, based on New York City’s Building Code and Sewer Use Regulations. The maximum penalty for not complying with the rules is currently $10,000 per day, per violation. To avoid the expense of such fines, install the correctly sized unit and maintain it properly.

For information about the City’s Sewer Use Regulations write to the address on the back of this brochure, or contact us on-line at

To report sewer back-ups or to get assistance with sewer, water, air or noise problems, call:


Or write to:

New York City Department of Environmental Protection
Bureau of Wastewater Treatment
Compliance Engineering Section
96-05 Horace Harding Expressway, 1st Floor
Corona, New York 11368