Getting Rid of Drain Flies in the Sink

How to Keep Drains Clean and free of Flies

If you’ve ever had difficulties keeping your sinks clean, you may have noticed a deeply unpleasant sight: a cloud of small flies hovering in and around the drains. These little fuzzy nuisances are called “drain flies,” though they are also often referred to as “moth flies” or “sewer flies.” They sustain themselves on decomposing food, which is why they are so fond of inhabiting and breeding in the drains of kitchen and restaurant sinks.

In addition to being a disgusting presence in your kitchen, drain flies can transfer dangerous pathogens1. By landing on decomposing food, food preparation surfaces, and food on tables, they increase humans’ risk of contracting foodborne illnesses. Considering that some foodborne illnesses can be deadly, it’s clear that this is no matter to overlook. In addition to Health Code violations, they can lead to outbreaks and lawsuits — more than enough trouble to shutter the doors of most restaurants.

Particularly as antibiotic resistance continues to rise, restaurateurs must be vigilant to avoid health risks. If you’ve already spotted drain flies in your kitchen, or if you haven’t already taken preventative measures, it’s time to take action. This guide will help you keep the drains in your commercial kitchen clean and free of pests.

Disinfect Sinks and Drains Regularly

Sinks and drains are breeding grounds2 for pathogens that can cause illnesses like hepatitis A, norovirus infections, staph infections, salmonellosis, and more. Keeping sinks and drains clean using the proper tools is a must.

The first step to tackling this issue is to regularly and thoroughly clear your drains. This will minimize the presence of decomposing matter (potential breeding grounds for pathogens that cause foodborne illness) and drain flies. As with any other part of your kitchen and dining area, this involves cleaning and sanitizing or disinfecting the drains. Following the advice below will help you do each of these steps.

Install Drain Covers and Grates

You can streamline drain maintenance by installing drain covers and grates. These can reduce the amount of organic material entering your plumbing in kitchens, bathrooms, and basement areas. These can also restrict pests’ access to such material.

The difficulty of installing these updates vary. Depending on the specifics, installing drain grates can be a fairly pricey and complex process — it’s best for those with limited DIY experience to reach out to a contractor. If you need to update your drain covers, simply remove one from one of your sinks and bring it to a hardware or restaurant supply store to find a suitable replacement.

Clean Grease Traps Regularly

Improperly maintained grease traps can lead to flooding and unwelcome pests in your kitchen. It’s important to regularly inspect these in order to determine when they should be maintained or replaced. Depending on how busy your kitchen is, you’ll want to clean your grease traps at least once every one to three months3. Contract a plumbing professional for an expert suggestion and evaluation of your grease traps to be certain you are maintaining them properly.

If you notice that it’s time for a cleaning, you must follow the proper steps to do so. To clean your grease trap:

  • Remove the lid from the grease trap and measure and record the amount of grease in it (to comply with EPA standards4);
  • Remove water from the trap with a bucket or pump;
  • Scoop out the grease — be sure to thoroughly clear the trap of any excess;
  • Scrub the trap down and clean the screens;
  • Return the water to the grease trap;
  • Reassemble the trap and replace the lid.

Regular degreasing throughout the day can help reduce the buildup of grease and simplify deep cleaning.

Keep Drain Clogs to a Minimum

The first step to preventing drain flies is to be proactive. If you notice symptoms of a clogged drain, take action. Some common signs that your drains are becoming clogged include:

  • Bad smells, often described as being like mildew, sulfur, fish, or sewage;
  • Water slowly drains — it may take anywhere from a few seconds to several minutes longer for water to drain after turning the faucet off;
  • When water drains in your sink, it produces a gurgling sound.

A quick search online will reveal many methods for clearing drains, but not all are advisable. While some will suggest using bleach to clear clogged drains, note that this isn’t the safest or most sustainable method. Simple skin contact with or inhaling the fumes of the chemical can cause damage, and bleach can pose an environmental hazard . Conversely, chemicals designed to clear your drains, such as Drano, can damage your plumbing when used improperly or excessively5.

Minor clogs can be handled by simply adding dish soap or salt to boiling water and pouring it down the affected drain6. You may also try using a drain snake to remove any clogs, though this is generally more effective for hair clogs, rather than food- or oil-based ones. When in doubt, look to your organization’s maintenance team or SOPs for drain clearing.

Scrape Plates and Food Scraps Into the Trash

An easy way to keep the drains clear of food scraps is to avoid putting them in there in the first place. Your workplace should stress the importance of clearing plates into the trash rather than the sink. Making this rule change and actively enforcing it may take time, but it will result in easier maintenance of your drains and fewer potential health risks.

Hire a Professional

Much of sink maintenance involves following simple cleaning routines, but if something goes amiss with your plumbing — or if your drain flies aren’t clearing away after repeated efforts — it is prudent to hire a professional. When selecting a plumber, ensure that the individual or business is properly licensed and has a good reputation.

Take Preventative Measures Against Drain Flies

Note that, while drains are a common culprit for drain flies (hence their name), dealing with flies is an all-around cleanliness and sanitation issue. The methods below will ensure your restaurant complies with sanitation standards and reduce pests of all kinds, helping to stay in compliance with Food Code requirements7.

Cleaning Tools

Every industry has its own cleaning products, and there are some essential restaurant cleaning products to consider. These include:

  • Hand soap and sanitizer
  • Dishwasher gloves and aprons
  • Brooms, mops, and squeegees
  • Cleaning solutions
  • Sanitizers and Disinfectants
  • Trash bags and liners

Work Areas and Equipment

Keep all work areas and equipment clean to minimize health risks and stay compliant with regulations. Food preparation areas, walls, floors, even garbage receptacles — keeping each of these clean and de-greased requires vigilance. Surface wipes can be used to keep all areas of your kitchen clean, particularly during busy periods of the year.

Dining Areas

In addition to thoroughly cleaning the kitchen, be sure to regularly go over all surfaces in your dining areas. Areas to pay particular attention to include tables (and everything placed on them — including menus), seating areas, doors, and windows. Keeping each of these areas clean will leave a good impression on customers, and employing appropriate sanitizers or disinfectants can reduce their potential exposure to flies and dangerous pathogens.