Why are slab leaks so common in Carlsbad, and is the clay really the cause?

Clay heavy soils expand when wet and shrink when dry, and that slow cycle bends and stresses the copper lines buried under slabs, year after year, until a pinhole or a split opens at a stress point. The head local operator's own framing names slab leaks as particularly common in older Carlsbad and Oceanside homes on exactly these soils. The clay does not make every Carlsbad slab leak inevitable; age, water chemistry, and pressure share the blame. It does explain the pattern: leaks cluster in the older slab neighborhoods, and a home that has had one slab leak deserves a pressure and line condition conversation, not just a patch.