This implies if the LL takes one month to place a tenant and a couple hundred dollars doing the always tenant turnover items (for example we always change lock cylinders, shampoo carpets, chemically treat the drains, deoderize/disinfect including use of ozoner). 

You will own a property that has these risks and 100 more:car falls on leg of customer and he is young and incapacitated and sues you tootenant pours poisonous degreaser into public plumbing an it leaks 200 feet to neighbor properties, they sue yourobbery happens and child is trapped in the bay and survives, the parents sue youteen comes in with their helper dog who bites clients, they sue youfireman falls through the roof in a fire (chemical fire) and is disabled because the roof wasn't to code...Although you are only the landlord you have duties to health and safety of the employees, clients who walk in, and the community.Look up: Ng to the Ghost Ship landlord in East Oakland

@Paul VailSomething else to be concerned about Meth houses is; where the occupants were dumping their waste chemicals.

Underground storage tanks, chemical seepage into the ground, etc...

Termador is the best chemical to treat termites in accessible areas but again, you need a branch II pest control license for that.

I know you would want a professional pool company to maintain it in case someone claimed your chemicals, or lack there of, made them sick.

As for the septic that could cause unique proportys in a rental, if your tennent doesnt know better they could really mess it up flushing things that dont degrade or kill the bacteria in the system by dumping household chemicals down the drain. 

There is chemical use that you need to be aware of and maintain compliance.

I ended up having to hire my own exterminator who would come and do a chemical spray every two weeks. 

There are different ways to "abate" lead: replacement (completely replacing any surfaces with LBP); enclosure (lead paint is covered with a wall covering like wall paper); removal (sanding and chemically removing the LBP from surfaces) and encapsulation (covering the LBP surfaces with a special chemical).