Grease Trap Regulations in Michigan

Overview

Michigan food service owners must follow FOG pretreatment rules set by the Michigan Department of Environment, Great Lakes, and Energy (EGLE) and local utilities. Michigan borders the Great Lakes. FOG-related sewer overflows carry serious environmental risk here. State plumbing code requires grease interceptors in restaurants, hotel kitchens, hospitals, school kitchens, bars, and factory cafeterias. Local water and sewer agencies run their own FOG programs. Each sets its own interceptor rules, cleaning schedules, and manifest requirements.

Governing Authorities

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) runs the Industrial Pretreatment Program. It uses federal and state rules to limit pollution from industrial discharges to public wastewater plants. EGLE also oversees Part 23 Rules. These rules set pretreatment standards and local limits for municipal sewage systems. Local utilities enforce these rules on a day-to-day basis.

The main municipal enforcement bodies are:

• Detroit Water and Sewerage Department (DWSD).
• Grand Rapids Department of Public Works.
• Lansing Wastewater Utility.
• Ann Arbor Water Utilities.

DWSD requires working grease traps for all food service owners. Each city runs its own FOG program with its own inspection schedule.

EGLE recommends cities require separators at source facilities through ordinance language. Local health departments may also have authority over interceptor sizing and installation.

Key Requirements

Interceptor Installation: The Michigan Plumbing Code requires grease interceptors for fixtures with grease-laden waste in food prep areas. This covers pot sinks, prerinse sinks, wok stations, floor drains where kettles are drained, and hood wash units.

Sizing Standards: Hydromechanical interceptors must meet ASME A112.14.3, ASME 112.14.4, ASME A112.14.6, CSA B481.3, or PDI G101. Size gravity interceptors by multiplying peak drain flow (gpm) by a 30-minute retention time.

Cleaning Frequency: Michigan does not set a single statewide cleaning interval. Most cities use the 25% rule. Clean when FOG and solids reach 25% of the trap's operating depth. High-volume commercial kitchens typically need service every one to three months. Detroit businesses must keep records of all grease trap maintenance for at least three years.

Record-Keeping: Records must show service dates, provider name, volume removed, disposal location, and any repairs noted. Keep them on site. Make them easy to access for inspectors at any time.

Waste Disposal: Michigan law classifies restaurant grease trap waste separately from domestic septage. Licensed haulers must transport it. It must go to approved receiving facilities only.

Fines and Enforcement

Michigan FOG penalties vary by city. Enforcement happens mainly at the local level. There is no uniform statewide fine schedule.

• Detroit penalties can exceed $1,000 per day for non-compliance.
• Detroit may also issue stop-work orders that force a business to close until it is back in compliance.
• Municipal utilities may bill cleanup costs directly to the owner for FOG-related sewer blockages.
• Repeated violations can lead to more frequent inspections and required compliance plans.

EGLE focuses on protecting treatment plant operations and preventing pass-through. Violations of Industrial Pretreatment Program rules can bring extra state penalties and permit changes. Operators should confirm fine schedules with their local utility in writing.

Major City FOG Programs

Detroit

As of 2025, DWSD serves more than 230,000 accounts — about 175,000 households and 30,000 businesses or nonprofits. It requires properly working grease traps for all food service owners. Fines can exceed $1,000 per day. Keep accurate records and clean on schedule. The department inspects regularly and requires three-year retention of all maintenance records.

Grand Rapids

Grand Rapids Department of Public Works runs a FOG control program for commercial food service owners. The city requires grease interceptor installation based on plumbing code standards and kitchen fixture counts. Typical cleaning frequencies range from monthly to quarterly depending on volume. Grand Rapids enforces state plumbing code requirements. Inspectors verify proper interceptor maintenance on site visits.

Lansing

Lansing Wastewater Utility runs a pretreatment program covering FOG discharges from food service owners. The utility enforces interceptor requirements under Michigan Plumbing Code standards and local sewer ordinances. Owners must keep accessible maintenance logs. They must also use licensed waste haulers for proper disposal of interceptor contents.

Ann Arbor

Ann Arbor Water Utilities maintains FOG program requirements for restaurants and food service operations. The city requires grease trap installation and regular maintenance to protect the sewer system. Compliance inspections check proper sizing, cleaning frequency, and record-keeping. Ann Arbor also stresses staff training on best practices to reduce FOG discharge.

Frequently Asked Questions

How often must I clean my grease trap in Michigan?

Michigan does not set a single statewide cleaning frequency. Most cities follow the 25% rule — clean when combined FOG and solids reach 25% of the interceptor's operating depth. High-volume kitchens typically need service every 1 to 3 months. Your local water and sewer authority may set specific minimum intervals. Contact your municipal utility for local requirements. Detroit requires three-year record retention of all cleaning activity.

What size grease interceptor does Michigan require?

The Michigan Plumbing Code requires hydromechanical units to meet one of these standards: ASME A112.14.3, ASME 112.14.4, ASME A112.14.6, CSA B481.3, or PDI G101. For gravity interceptors, multiply peak drain flow (gpm) by 30 minutes to get the minimum size. Your local building department and sewer utility review sizing during permitting. Consult a licensed Michigan plumber for a proper calculation.

Can I clean my grease trap myself or must I hire a licensed hauler?

Michigan law does not ban self-service of small under-sink traps. But most cities require licensed haulers for larger interceptors. Michigan classifies restaurant grease trap waste separately from domestic septage. Disposal must go to approved facilities. Licensed haulers provide proper manifests and meet the 25% rule. Most commercial kitchens use professional service.

Find Grease Trap Service in Michigan

We list 42 qualified grease trap service providers across Michigan. These companies offer pumping, cleaning, maintenance, and compliance records. They cover Detroit, Grand Rapids, Lansing, Ann Arbor, and beyond. Visit our Michigan grease trap service directory to connect with licensed providers and stay compliant with EGLE and local wastewater rules.