I am currently helping out on a project that has a few drainage issues. Water is getting inside the building's crawl space. There is 2 spray zones near the building. They just put some tile next to the foundation and drained that into 33 gallon drainage basin. Ran the 2 zones of sprays for 15 mins each and the basin was full of water within a hour. The guy in charge is convinced that the 2 zones are leaking underground somewhere so he wants me to test the latterals to see if they are leaking.............it is a 13 year old system with drains. So next week I am going to pressure test the zone. Any thoughts about what would be a acceptable amount of loss in the zone pressure over time??