How to best use one jQuery version (or least amount of versions) for WordPress.

How to best use one jQuery version (or least amount of versions) for WordPress.

So, I'm managing a WordPress site which quite heavily uses jQuery. The site already has multiple version of jQuery and I'm not sure where to start to cleaning up this mess. I don't want to have to use noConflict every time I want to use jQuery myself, and I don't want to break the site when I trying to organise it all.

Am I putting too much emphasis on standards by wanting to use only one version on the whole site? Maybe it's wishful thinking...
 
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Anyone have any ideas on how to manage this or a link to an article or anything?