School teacher Sherry Meinberg was surprised when her students suddenly started screaming in her classroom one day. The students were alarmed at what appeared to be a “big black geyser coming out of our sink,” Meinberg recalls. The geyser was a stream of cockroaches pouring out of the drain and into the sink. Meinberg called in the school custodian and sent her students home for the day.
While unusual, it is not uncommon to see cockroaches coming out of drains, especially in older buildings. When they detect pesticides, cockroaches have been known to try to escape from the poison in any way possible, including out of sink drains. Meinberg’s recollection tells us a few things:
- Insects, including cockroaches, tend to be a problem in many older facilities.
- Insects are developing immunities to many of the insecticides used for years to eradicate them.
- Cockroaches appear to be smart enough to detect pesticides and look for ways to avoid them.
This incident also pointed out that when such an event occurs, the first people likely called in to address the problem are cleaning crew members. However, two different groups in a facility—building managers and cleaning workers—ultimately work together to eradicate pests.
Cockroach Living Habits
While cockroaches do make homes in various types of facilities, both new and old, many often start their lives outdoors in mulch and vegetation, especially in the southern or warmer parts of the United States. When it gets too cold or too hot outside, they start looking for a new home. Instead of invading a facility directly, they often make their way into sewers, which tend to be warm and dark. Sewers provide the food and water insects need to survive and also offer protection from weather conditions. Cockroaches are explorers and soon start crawling up dry drain pipes, laying their eggs as they go. As the nymphs hatch, they continue creeping up and out of drains, often ending up in dark storage rooms, garbage rooms, basements, etc.
Discovering cockroaches in a basement area or coming out of a floor drain typically tells us:
- They have found ways to invade the building from the outside.
- They are hungry and looking for food.
- If you see one cockroach, there are many more where it came from.
- You should expect sewer odors to follow the arrival of cockroaches.
How to Take Action
Aware that many cockroaches and other insects are no longer intimidated by insecticides, building managers have little choice but to call a pest control company as a first step. The pest control company can help identify the type of cockroach infestation the facility is dealing with, verify how the cockroaches are getting into the building, and offer treatments to eliminate the pests.
“P,” “J,” or “U” traps are found under virtually all sinks, including floor drains. The purpose of these traps is to hold water, which helps prevent sewer odors from escaping into the building and blocks cockroaches from making their way up floor drains, sink drains, etc. Maintaining facility drains is an important task for custodial crews. The first step is to conduct a drain audit. Know the location of all the drains in the facility. Pay special attention to restroom floor drains.
Next, prevent cockroaches from traveling up sewer pipes and through dry floor drains, by ensuring floor drains are flushed every week. You can make sure drain pipes do not dry out by using the below:
- Water: Pour two cups of water—no cleaning solutions, bleach, or other chemicals are necessary—into all floor drains and rarely-used sink drains at least once per month. In hot and dry climates, you may need to do this weekly.
- Cooking or mineral oil: Pour a thin layer of cooking/mineral oil down drains to keep water from evaporating for a few weeks, possibly months. Perform this task every six weeks to two months.
- Trap primer: A plumber can install a trap primer at each water supply. The trap primer detects when trap water has evaporated then releases small amounts of water into the drain to refill the trap. Some trap primers work with sensors, others with timers.
- Liquid trap seal primer: First pour water down the drain, then pour this odorless, biodegradable liquid. Primers last three to six months or longer.
These methods will not only keep the drains and traps filled with water to help prevent a cockroach invasion, but can also help stop sewer odors from escaping into restrooms and other areas of a facility. The release of sewer odors can be more than unpleasant, it can be dangerous if the odors contain toxic gases. Taking steps to maintain facility drains is one more way that cleaning crews can help keep people healthy.