plantitselfshouldhavea grass-freestriparound the building, whereit is not
pavedto the outside wall of the building. Thisgrass-freestripshould be about 30
inches(0.75m) wide,fourinches (100mm)deep,and linedwitha thickpoly
linerto keepweedsdownand thenfilledwithpea gravel.Pea gravel(small
rounded gravel)is recommended because it will not bridge if a rodentattempts
to burrow throughit to get underthe plant slab.This stripmakes it easierfor the
plantsanitarianinspectingthe buildingfor rodentactivityand is a deterrentin
itselfsincerats do not like openareasand will avoidthem.It alsomakesan
excellent stripto placebait stations.
Anotherrodent deterrentis the construction of a horizontal lip fastened to the
foundation of the plant.Thisledge or lip is located 24 inches(0.6 m) below
gradelevel and extendshorizontally 12 inches(0.3 m). Thislip can be either
concrete or 16 gagemetal. It has beenshown that rodentsburrow at an angleand
oncethey hit that lip they will eitherburrow alongit or will retreatto the surface
and try somewhereelse.
As part of the landscapingeffortbushesshouldnot be placed less than 30 feet
(9 m) awayfromthe structure. An alternativeis to havethemplacedfar enough
awayso that when they are full-grownor at the trimmedheightthat a full-grown
personcan walkbetween the bushesand building to inspectfor pests.The
groundaround the bushesshould be covered withpea graveland not mulchor
soil. Treesaround a plantare not recommendedsincetheyprovide roosting and
nestingspotsfor birds,so attractingthemto the facility. However,if treesare
desiredor presentit is recommended that theybe at least30±40feet (9±12m)
awayfromthe facility.Selecttreesthat are not attractive to birds for nesting and
roosting. Consult a locallandscape gardener for a list of suchtreesthat will grow
in yourlocation.
All grass areasshouldbe keptmowedor shortto prevent harboragefor
rodents. Driveways, parkinglots, and dumpster areas should be pavedand
slopedto drainswhich providesufficient drainageevenduringstorms. The
stormsewerinlets shouldbe in accordancewithacceptedengineering standards
for groundwaterrunoff as wellas regulatorystandards.Thereshould be no
standing wateranywhere on the premises in orderto reduce attraction to birds,
insects and rodents or other pests.Dormantwaterpuddles can become a source
of foodborne microbiological contamination.The dumpster station should be
equippedwitha hoseso it can be washeddownaftereachremovalof full
dumpsters.
The perimeter of the grounds should havea chainlink typefenceto keepout
largeranimals,people,and children,and to securethe premises. Tall weedsand
grassshouldnot be allowed to grownearthe fence and it should be keptfree of
any debristhatcatchesin the fencing.Thefence lineshould be inspected
frequently for housekeepingpurposes and to makesureit is in goodrepair. A
perimeter fenceprovidesa firstline of defenseagainst rodent and is a good
locationfor bait boxesif allowed by local ordinances.Thesebait boxesshould
be placed50 to 75 feet (15±22m) apartand be securedeitherto the fence or to
the ground.
Improvingbuildingdesign 129