Sick Ash trees
The invasive Emerald Ash Borer is killing trees over most of Maryland, and has been found in Calvert County.
If you have ash that have the symptoms featured on this page, we'd recommend to go ahead with removal: http://extension.umd.edu/hgic/invasives/emerald-ash-borer
You should act sooner rather than later to remove if it's fall would threaten people or property, as these trees loose their structural integrity pretty quickly. Some arborists or tree companies either refuse to climb them or add hazard fees because the wood weakens so quickly. The link above helps you to find companies licensed to do the work properly.