Faulty STP/ill maintained STP - where to complain?

I am a resident of Bangalore living in an apartment complex for almost a decade now. Residents of my apartment complex have been suffering with faulty/ ill maintained STP for several years. Several complaints to builder/welfare association have fallen on deaf ears. Black, untreated water often infested with worms is a regular scene for us. Where do residents like us lodge a formal complaint? Is it with the pollution control board or with local sewage authorities?