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I was reading a newly published cheese book, Farmstead and Artisan Cheeses by Reed, Butler, and Rilla which claimed that once Listeria is found in a cheese plant it must be torn down and rebuilt.  This just seems a bit far fetched.  I understand Listeria is a bad thing, but this would make it seem un killable.  Is there any truth to the claim?

Imagine the money insurance companies would have to come up with if that was true.
The insurance lobby would never allow it.   

A more reasonable scenario is destruction of any suspesious products and idenifying the source of infection and killing it. either by chemicals,steam ,gas. (In theory you can sanitize a room given enough ozone gas or enough contact time with ozonated water) and even low level iradiation can be used.

Bollocks. However, what the truth is and what science supports may not be politically viable. Meaning in practice, most people don't know enough to eradicate listeria properly once it gains a foothold. And regulators may not be willing to take a chance because of this reality.

Tomer, the regular procedure for pathogen-contaminated areas may not work because there are often biofilm issues to consider.

As is often the case, in writing, it is usually easier to post a half-truth or three-quarters truth that should be used as a best practice than write about the issues and the dynamics behind them.

The claim may be a bit of an exageration, but the fact is that lysteria is extremely difficult to remove once it is established in a factory. It loves cold damp places and thrives under floors, in drains, coolrooms etc, particularly in older factories which may have damaged infrastructure like cracked floor tiles and drains. lb's point about biofilms is also true, making it more difficult to kill the little devils.  The real risk of course is if the bacteria travel from the contaminated floors and drains onto product contact surfaces such as tanks, fillers or wrapping machines, or even into air distributiion systems. These risks are all manageable, but require very thorough sanitation regimes and procedures. Considering also, the very serious outcomes of a serious listeria contamination, up to and including complete loss of  the business,  it is sometimes a safer solution to build a new factory and start again. (with significantly improved hygiene controls of course)

So very true. The reality is that if in a plant it's gotten so bad that there is persistent contamination (ie not isolated to far away and usual spots like drain manifolds), bigger issues than listeria to worry about because it's an overall hygiene systems failure. If a plant is not managing biofilm formation actively and proactively by checking common places where psychrotrophic bacteria like to hide, such areas of heat/humidity differentiation that cause water pooling (eg ducts), filters, contact and non-contact surfaces (gears in a machine that had some whey splashed on it), crevices that held contaminated brine, scratched equipment... then no amount of emergency cleaning will help long term, because there's a high likelihood it will just be reintroduced, and en even higher likelihood some far away spot will remain (say, calcified water stain on a sprinkler head in the cave).

But other issues, like a single bad batch or contaminated brine, or other limited vector pathogen payloads, those aren't so bad.

Gone consider that when I design my winery-creamery business.

Of course, reputable companies that have good hygiene practices would never let their plants get to the stage where the building and equipment infrastructure was such a risk. They would ensure that corrective actions were taken before such an issue became critical. Whilst infrastructure repairs are usually expensive, they are cheaper than a full relocate and rebuild.