I'm glad we don't have to test those underground backflow preventers.
I would be pissed.
The assemblies we installed had sufficient side-by-side clearance, unions, gravel sump with at least 8" of clearance below and a jumbo or larger v.b. Testing was a snap. Now, "installed by others" were a major p.i.t.b. and more than a few we refused to test.