The current code that runs when a deposit is found spawns miners from the prospecting table. This runs from the nearest stargate if no outlaw mines are active, or from mines if they are. They then proceed to the area of the deposit, attempt to mine it and/or kill the player, and then leave. There is a timer that repeats this over time if the deposit is still present. However the number of overall miners is not capped, nor is the number of times the timer runs. It's not uncommon for players to end up 'mining' the outlaw miners more than the asteroids.

There should probably be a limit on how many stations can spawn outlaw miners into a wave, as well as a cap on the number of waves per deposit. I suggest tying this to system level so that mining in Eridani is easier than elsewhere (you can end up with upwards of twenty borers lemming-training into the inner system over the course of five or ten minutes at present).