Septic tank advice and recommendations in north Wicklow

tldr: specific recommendations for septic tank assessment by PM only please as per charter.

I'd really appreciate advice on how to proceed....

I've just bought a house in north Wicklow. It was built in 1987 and has an original septic tank, registered in 2012. The site is approx 0.8 acre, sloping, with the tank starting approx 10m downhill of the house and presumably percolating towards the site boundary (approx 40m from the house).

The former owner told me he gets it desludged every 5 years and then throws in a dead chicken to kick things off again. It's now at year 4 of that highly sophisticated cycle.

I've never had a septic tank before and am trying to do the right thing w.r.t avoiding bleaches, bio washing powder etc.

All fine so far.

However, the tank and percolation area is right in the middle of the rear lawn, with a large ugly weeping larch and several enormous shrubs sat on top of it. The two inspection hatches are underneath the tree.

I want to re-landscape the garden and move the tank (or replacement treatment system) somewhere less prominent. I could re-landscape around it but I'm not sure that makes sense - if I get inspected or need planning for changes to the house I may need to upgrade the system.

So I'd rather just get a final solution sorted now and free up the main garden area for more attractive features.

Does this make sense? Or should I just kick the can down the road until I actually need to do it. There is a housing estate planned (but not granted permission yet) within 50m of my boundary which presumably will need mains sewer connections. Would I be able to piggy back on those?

Anyway: recommendations for a professional to advise on these issues appreciated. I'd rather not use someone who also does installations since they're likely going to recommend a replacement.