Performed comprehensive leak detection due to reported water damage in the kitchen area. Initial pressure test of the domestic water system indicated a minor pressure drop after 15 minutes. Upon systematic inspection, a slow drip was identified at the laundry sink. I shut off supply to the laundry sink and re-pressurized the system, which then maintained pressure with no further drop, confirming no additional leaks in the domestic supply lines. Further investigation into kitchen water damage revealed pooling water within the wall cavity behind the dishwasher. Water exhibited a foul odor consistent with graywater or sanitary waste, prompting interior wall and slab exposure. Opened drywall and chipped concrete to expose the 1½” copper waste arm. Located an 8” section of original copper drain line exhibiting severe channel rot along the bottom. This deterioration was actively leaking during sink operation. Customer advised that the kitchen waste arm was previously “replaced” prior to home