[Copesan University] Clean Drains Promote Small fly Control

Editor's note: This article was excerpted from materials developed by Copesan. Copesan’s Internet training program, Copesan University, is now available to the entire pest management industry. Click on the Copesan University logo at www.pctonline.com for available courses.

If your customers have flies in their facilities, you as the pest management professional need to correctly identify and treat the source so the problem doesn’t persist after treatment. Drains present one source of flies that isn’t always obvious, especially if the drain looks clean on the surface. For example, floor drains that fail can leak fluid into inaccessible spaces and soil, creating organically rich environments that will attract and support insect growth. Phorid flies, drain flies, fruit flies, dung flies and American cockroaches are some of the more common insects associated with failed drains and plumbing.

ANATOMY OF A FLOOR DRAIN. While there are many different types of drains — round, square and long, narrow trench drains — all have grate-like metal covers on the top surface. Under the floor grate, many have a removable basket designed to trap and catch solids before they are washed into the drain pipe and cause a clog. Some drains have a second catch basket under the first. Beneath the drain is a length of pipe, called a trap, that is designed to hold water and keep sewer gases and other odors from backing up into interior spaces. The trap is often located 12 to 24 inches below the floor grate and, in most cases, it is visible, but it can sometimes be located many feet away and not accessible or easily seen.

WHY DRAINS FAIL. Floor drains can fail in different ways:

• The flange at the top of the pipe, or recessed space in the floor, can separate from the floor tile, allowing liquid waste and wash water to leak into the adjacent space and not go down the drain completely.
• Old pipes (especially cast iron ones) can become brittle and crack. Buildings subject to settling can put stress on the waste pipes causing them to bend and twist, creating leaks and breaks.
• If a drain’s water trap is allowed to dry out, small flies breeding in septic tanks or grease traps further down the pipeline can move back up the drain. This sometimes happens when a floor is damp washed and water is never flushed down the drain to keep the U-trap charged with a volume of water. This type of drain can easily be kept full by making sure water is flushed down it on a regular basis.

The most common reason drain systems fail is because they are not kept clean. The larval stage for the flies reported previously is semi-aquatic, and they must feed and live in wet, organically rich waste. Drains catch this waste if they are not routinely cleaned. If they are not cleaned, the perfect fly breeding medium is created. Contaminated waste water has organic solids and will accumulate over time in and on the catch baskets, the under-side of the floor grate and on the sides of the drain pipe itself.

RECOMMENDATIONS. Here are some tips to help your customers keep their drains clean:

1. Regular cleaning is necessary. All establishments should open their drains and clean them on a regularly scheduled basis, even if they look clean on the surface. Pouring cleaners and biological agents down drains without first physically cleaning the floor grate, catch basket and pipe is not effective drain cleaning and will not work to eliminate conditions conducive to fly breeding. These areas need to be scrubbed with a stiff brush. Then cleaners and biological agents can be used to keep the drain cleaner for a longer period of time.

2. Employees need tools and instruction. Employees responsible for cleaning floor drains need to be given the proper tools necessary to open and physically clean the drains, as well as instruction on how the drains should be cleaned. When staff changes, new personnel need to be trained.

3. Drains must be accessible. Designers and planners of new construction and renovations must never allow drains to be constructed under equipment, making them inaccessible or difficult to reach for cleaning.

The author is technical director for Waltham Services, Waltham, Mass.