I planted my impatiens a week before Mother's day and they grew and bloomed beautifully until the last week in July when our landscapers trimmed our shrubs. I'm not sure what they did, but our Impatiens are now almost bare and look sick. Is it possible that the leaf blowers used to clean up the shrub clippings damaged our Impatiens?

It sounds like the Impatiens have contracted downy mildew (a different entity from powdery mildew.) There are a lot of articles "out there" about it affecting Impatiens walleriana plants.

Since this is an airborne disease, the leaf blowers could have spread the spores to your impatiens.

It also persists in the soil so if that's what it is then don't plant impatiens again in that same area next year. If they were already infected, though, it could just have been coincidental timing. The times I've seen it the plants appeared to be doing fine for some time and then suddenly started a rapid decline.

Rick, I'm also in Warminster PA and I have the same problem! DOWNY MILDEW!
I never had this before. My impatiens all looked great but in the past week or so they all have been taking a slow dive. One area all needed to be pulled in under a week. I posted a question wondering if a spray made up of baking soda/dish soap/water would help. I'm trying to save some impatiens that look like they're still half alive.
I don't believe I bought infected plants as all of the plants I did buy were purchased back in early June.
I think since we had under normal temps during the past 2 weeks, and with all the rain recently furthered the problem.