After doing a search on "oak, wilt, mulch" and excluding the dot .com
sources and focusing on the edu's and org's. I saw that the consensus
was that since moisture content in the wood material was a necessity
for the fungal spores to survive, if the mulch is chipped and dried
the mulch is virtually safe from infecting other Oaks.
You would have to have a situation where the mulch had retained
moisture content since the time it was shredded and you would have to
have the vector of the sap beetle traveling from the mulch to an open
wound on the tree at the time of the year when the spores are
reproducing. This succession of events is necessary which is why the
odds are so small and 'virtually safe'

The original question refered to materials available at city or
town dumps. I would be more comfortable with materials from one of
the good landscape material sources here in Austin like Geogrowers or
Natural Gardener than I would from a town dump unless I was able to
see that the material was shredded finely and then left to dry.

I've seen bagged goods shipped in on pallets from East Texas that
were stored out in the rain at their point of origin, were soaking wet
and often when opened contained fungal spores ( of some sort ) and
beetles.
One of the best things about shopping for locally produced
products is that it's usually not that hard to get the owner to let
you see the process.
I'm alot more comfortable with John D. overseeing the process than an
agribusiness in another state.

A number of sites I looked at, stressed the importance of the material
being finely shredded. Material that is not finely shredded is more
likely to hold moisture and harbor spores.
Austin Parks and Recreation has an Oak Wilt FAQ available at
their web site that warns of using infected firewood, and to not store
it on your property. They suggest that you make sure you get only
fully dried firewood if your buying Red Oak for your fireplace. I
noticed the Minnesota sites also talked about this a great deal, (
makes sense, they actually need fireplaces up there )

This whole topic of how much risk we are willing to tolerate for
the obvious good of recycling our green materials on a large scale and
not burying them in the landfill, improving our soil on a large scale
with readily available mulch is really important.

It reminds me of what happened today while eating breakfast at
Guero's on Congress avenue today. I ordered migas, bacon and coffee.
I was in a hurry so I asked the waitress to bring me the coffee in a
to go cup.
The young lady leaned in close and said it wasn't healthy to be
drinking coffee out of a styrofoam cup. I told her ," It might be" ,
but look ing at my meal, I said , " I already am eating bacon with my
migas. I'm taking a calculated risk for the better good. "

Steve Coyle
www.austingardencenter.com