We made a post about swimming, with some links, several months ago. The main issue is risk of exposing yourself to the pollution, micro organisms, and further risk may be based on how your immune system is. The safest seemed to be a pool, but others were more risky. The link has several coverings for pegs, Tracts, ports. I used Saran Wrap the first week the peg was placed, and was thinking about going to an indoor pool, and using it, idk yet. Activity wise, you have be careful of the type, level, not to pull the peg out, which surfing seems it could, and would need some type of protective measures as some mentioned.

As far as landscaping, the issue is exposing yourself to bacteria in the soil with a compromised immune system. A person should wear gloves, mask, and other protective equipment, and is best checking with the doctor.