Periodically, I find the ground wet from an underground sprinkler hose which has sprouted a pinhole leak. I have to dig up the hose and splice a new section of hose in which is a major pain in the neck. The leaks appear anywhere in the line and no stones or roots are near the leak. Is there a reason this happens? The hose is standard black plastic hose that sprinkler companies used when the system was installed and it is fairly old. Still, I don't see a reason for pinhole leaks to happen unless the hose was substandard to begin with. Is there any way to avoid this? I'm a newbie here so please advise what I can do to prevent this from happening regularly. Thanks.