Rats Under Our Feet

By Dr. Stuart Mitchell

Across the U.S., unprecedented infrastructural decay is perpetuating wide-ranging damage and failure of sewer systems. Generally out of both sight and mind, sewer systems are one of the most important infrastructures and vital to public health. Combining sewer system decay with this influential pests’ abilities to swim one half mile in open water, swim against substantial current in sewer lines, and swim through plumbing water traps, rats are increasingly and literally under our feet.

In 2011, a U.S. Senate Hearing discovered it would take $330 billion to upgrade the nation’s sewer systems. According to an American Society of Civil Engineers’ study, an additional $9.2 billion per year will be required for water and sewer system maintenance and repairs through 2020. Increased interruptions in water supplies and increased contaminations from sewer micros will become the norm. Additionally, increased pestiferous conditions will proliferate and emerge from under our feet.

A daunting challenge, yet unprecedented opportunity for pest management professionals, sewer systems must become as essential and routine an inspection region as the structural landscape, exterior, interior, roof, and inbound-outbound traffic. Sewer system awareness is accomplished through both proactive and failure based camera inspections by a licensed plumber.

• Subcontract a licensed plumber or plumbing contractor to conduct and document periodic, if not routine, sewer line camera inspections.
• Document inspections as part of the Master Cleaning Schedule (MCS) or equivalent document (routine inspections).
• Facilitate correction of failing sewer lines.
• Facilitate repair or replacement of sewer line failures.

Used by rats, sewer systems are routes of entry into structures. Upon occasion, rats wriggle up and emerge through toilets. (See a video from National Geographic showing just how easily rats can come up through toilets.)

• Install and secure metal grates over floor drains (grate openings smaller than 1/4 inch across).
• Install sewer floor drain back-up preventers (by a licensed plumber).
• Contact and work with with local sanitation and health departments regarding sewer system rat management programs.
• For rodenticide bait block applications within sewers the label may state: run a wire through the holes in the bait blocks and attach the wire to a stationary structure such as the bottom step of a manhole ladder or to a sewer grate, allowing just enough wire for the blocks to rest on manhole benching. If benching is not present, suspend bait block a few inches above the high water line or place blocks on a board supported by opposing steps of a ladder. Securing blocks in this manner will minimize the chances for removal by rats or water. Place at least 12 bait blocks per manhole.
• Always read, understand, and follow the rodenticide label!

Across the U.S., aging and decaying sewer systems will be a significant challenge to municipalities for many years to come. Aging and decaying sewer systems will provide significant increases of invasive pest pressures. Right under their feet, pest management professionals will realize incredible specialized service revenue opportunities!