I was told by the septic people that, for this new septic, neither detergent pods nor bleach should be used, because it can clog the system and harm the bacteria (it's a biological septic system).

nothing takes pee out of carpet because probably not in it but in padding and subfloor, when you do pull up you will see, may be able to pull up a corner to check, I bleach floor underneath first before sealing because of bacteria, then install vinyl without seams or will seep again or waterproof surface,  no pets is not always the solutions as you should see what damage including urine humans of all ages could do, at least with pets easier to collect for damages

Astro-turf is not a bad idea but you have to treat it for bacteria growth. 

I even experimented with a property that is so dilapidated and off the grid, bacteria will stay away.

There is also 'stuff' you can buy that 'eats" away at the bacteria that causes the smell left by cat urine.

Alot of times it's a bacteria problem from not using the correct chemicals right. 

People that are new to septic systems should familiarize themselves with basic septic maintenance - treating with bacteria monthly - not using bleach etc.

Errant baseballs can break windows and cause concussions and baseball gloves will get sweaty and full of bacteria.

If that didn't get rid of it.... 2) Bacteria is what's causing the smell so you need something that will kill it.

These machines kill the bacteria in the air.