Grease Trap Regulations in Massachusetts

Overview

Massachusetts food service sites must meet FOG pretreatment rules from the Massachusetts Department of Environmental Protection (MassDEP) and from local sewer authorities. The Board of State Examiners of Plumbers and Gas Fitters requires sites that produce fats, oils, grease, and solids to install grease traps or interceptors that meet 310 CMR 15.230. That covers restaurants, hotels, hospitals, and clubs. The state minimum is a four-foot depth and a 1,000-gallon capacity. Local enforcement comes from the Massachusetts Water Resources Authority (MWRA), the Boston Water and Sewer Commission, and dozens of municipal Public Works departments.

Governing Authorities

MassDEP protects the state's air, water, and land for public health and safety. MassDEP regulations at 314 CMR 12.00 set the standards and pretreatment rules that keep wastewater treatment works running.

The Massachusetts Water Resources Authority (MWRA) sets facility maintenance rules. Sites must inspect traps and interceptors monthly for damage or other issues. Sites must clean the trap when it hits the one-quarter rule or at least every three months. The Boston Water and Sewer Commission enforces local FOG rules in Boston. Local Boards of Health are the main regulatory authorities in most cities. MassDEP oversees variances, shared systems, and large systems.

Under the Massachusetts Uniform State Plumbing Code (248 CMR 10.09), interceptors must catch discharge from any fixture that may produce grease-laden waste anywhere food is prepared. Title 5 (310 CMR 15.000) covers on-site sewage treatment and disposal systems. That includes grease trap standards for sites with private disposal systems.

Key Requirements

Interceptor Sizing and Installation

• Grease traps must be at least four feet deep and hold at least 1,000 gallons.
• Grease traps must be watertight. Install them on a level, mechanically compacted base. Backfill them properly to avoid damage.
• Only gravity interceptors and hydromechanical or engineered systems that have been tested and approved to the right standards are allowed.
• The plumbing fixtures connected to grease traps must include pot and scullery sinks deeper than ten inches, floor sinks and drains, automatic dishwashers, pre-rinse sinks, hood wash units, and soup kettles or similar units.

Cleaning Frequency

• 310 CMR 15.351 requires the owner or operator to inspect grease traps monthly. A licensed septage hauler must clean the trap when the grease layer hits 25% of the effective depth, or at least every three months, whichever comes first.
• Internal grease traps need monthly cleaning. External grease traps need cleaning at least every three months to keep working properly.
• Point-of-use traps need cleaning at least once a month. Large in-ground interceptors need quarterly cleaning. The trap must be fully emptied at least once a month.

Record-Keeping Requirements

• Keep records of buying, storing, and removing grease-related products on site for three years. That includes Small Commercial Discharge Authorizations, Inspection and Maintenance Forms, hauler receipts, manifests and bills of lading, and a full inventory of food and maintenance products.
• Septage haulers must fill out a System Pumping Record and send it to the local Board of Health or Regulatory Agency within 14 days of pumping.
• Massachusetts requires qualifying sites to hire a licensed septage hauler with the proper equipment for grease removal.

Prohibited Practices

• You may not use chemical or biological agents or any physical means to release FOG into the sewer or bypass the trap. Doing so counts as illegal dumping and brings fines and harsh penalties.
• Chemicals, liquids, or agents used to emulsify or separate grease so it can move from the trap to the drainage system are banned, unless the Board accepts them.

Fines and Enforcement

Penalties for FOG violations vary by city in Massachusetts. Local sewer authorities and Boards of Health publish their own per-day fine schedules. Water resource authorities may add civil penalties, require compliance plans, mandate the install of properly sized exterior interceptors, and recover clean-up costs for blockages and sewer issues.

If FOG damage to a city sewer system is traced to your site, you may pay both the repair costs and fines. Failure to comply with local rules can lead to fines, business closures, environmental harm, and revocation of business permits.

Local Boards of Health can suspend or revoke food service permits if a site fails to fix a violation. City sewer commissions can also pursue legal action for costs from a violation. That includes legal fees, administrative fees, disposal and cleanup costs, and damages.

Major City FOG Programs

Boston

The Boston Water and Sewer Commission requires grease traps on sewers that may receive significant animal or vegetable fat, oil, or grease. The discharge concentration must not exceed 100 milligrams per liter. Sites must clean the trap when 25% of the trap's liquid level is grease or oil. City officials wrote the 25% rule to require traps to be emptied when they reach 25% capacity. Owners must keep maintenance records on the Grease Control Log. The log notes the date cleaned, the amount removed, and a confirmation signature. The trap must be fully emptied at least once a month. The only additive BWSC allows in the sewer system is bacteria. Bleach, emulsifiers, enzymes, and other chemicals are banned.

Worcester

Worcester requires proper grease trap maintenance under local rules to protect city infrastructure and waterways. The city sits near the Blackstone River and other water resources, which makes proper FOG management important for local ecosystem health. Cities across the state set cleaning rules based on several factors. Those factors include the size of the trap, the actual thickness of the grease, the amount of sludge in the trap, the type of food service site, the amount of food processed, the seating capacity, and the wastewater flow into the trap.

Cambridge

Cambridge food service sites must comply with state plumbing code and local enforcement by the Cambridge Department of Public Works. Cambridge businesses depend on reliable grease trap maintenance to avoid downtime and sanitation problems. Cambridge enforces the state standard of monthly inspection and quarterly cleaning.

Plymouth

More than 70 percent of food prep businesses in Plymouth were not in compliance with state rules requiring grease traps to be pumped and cleaned at least once a year. Commercial kitchens and facilities must follow the rules. They must get traps pumped and cleaned annually with proof of service, or risk fines and license revocations.

Springfield

Compliance challenges show up across Massachusetts cities, including Springfield. Local Boards of Health enforce state standards alongside city sewer authority rules.

Frequently Asked Questions

How often do I need to clean my grease trap in Massachusetts?

Massachusetts regulation 310 CMR 15.351 requires the owner or operator to inspect grease traps monthly. A licensed septage hauler must clean the trap when the grease level hits 25% of the effective depth, or at least every three months, whichever comes first. Internal traps usually need monthly cleaning. External interceptors need quarterly cleaning at minimum. The 25% rule is the standard across the state. Never let grease and solids exceed one-quarter of your trap's capacity.

Who can legally pump my grease trap?

Massachusetts requires qualifying sites to hire a licensed septage hauler with the right equipment for grease removal. State and local rules require the service to be done by a licensed and permitted "Offal Hauler" or "Grease Hauler" registered with the state and authorized to transport and dispose of grease waste properly. Self-cleaning of small internal traps may be allowed in some areas. Pumping records must still be sent to local authorities within 14 days.

What records must I keep for my grease trap?

Keep all records of buying, storing, and removing grease-related products on site for three years. That includes Small Commercial Discharge Authorizations, Inspection and Maintenance Forms, hauler receipts, manifests and bills of lading, and a full inventory of food and maintenance products. Keep logs that show inspection dates, grease and sludge measurements, cleaning dates, hauler info, and volumes removed. These records must be available to local health officials or sewer authorities for inspection.

Find Grease Trap Service in Massachusetts

GreaseTrapLocator.com lists 57 qualified grease trap service providers serving Massachusetts communities. Our directory connects restaurant owners and facility managers with licensed septage haulers who meet state rules for FOG removal and disposal. Whether you operate in Boston, Worcester, Springfield, Cambridge, or any Massachusetts city, finding a compliant service provider matters for avoiding fines and keeping your food service license. Browse our Massachusetts grease trap service directory to compare providers, read reviews, and book service with pros who know the Commonwealth's rules.