Soak pit and borewell in close vicinity in Chennai

Issue regarding contamination of borewell water due to the soak pit

My apartment is in Madambakkam near Tambaram, Chennai and there is no drainage facility in my area. We have 3 soak pits around my flat for the sewage water (from bathroom and washing machine). However, a pit at one corner is adjacent (11 feet) located from my neighbour's borewell. The borewell is about 350ft deep. There have been no issues for the past 4 years. But, now they are complaining that their borewell water is getting contaminated because of my pit. Will it get contaminated? Is it okay for me to continue with the pit? Or what remedial action should I undertake?