Well done Carmelo. Lismore Council has fabulous details about reed beds. We have found that if one council has done the work, others are happy to accept. I agree with S. that you need a grease trap. Our grease trap saves more than we would have thought. We put the grease (soap scum, hair and food bits) into the compost and it breaks down by chook scratching.
https://www.eco-reed.com.au/examples.html
We have a split system where the toilets (Black water) go into one pit and the rest (Grey water) goes into another pit. The grey water has a grease trap and needs a clean out about twice per year. We built the reed bed ourselves.
The local council insisted on an absorption trench but with sodic clay soils, it clogged in a few years and stunk. The reed bed discharges into a 1 Cu M underground sump that has casurina near it, with the result that there is no stink, no lying water and an amazing thing is that the Kangaroos are eating the grass around the same area. This makes me think that the grass is sweet and not toxic. Casurinas (River Sheoak) are fire resistant so form part of our fire mitigation plan and winter prevailing wind break.
Have a look at this site.
https://www.wormfarm.com.au/ These guys install worm composting sewerage systems. They have done a lot of work with councils.
Good Luck with it all. If you want to chat further about this, just PM me.
Cheers