Fosse septique regs - authority

Does anyone know whom I should contact regarding: my neighbours are emptying their broken micro station (fosse) dirty water into a well which due to the history of the property is attached to my pond - I have requested that they resolve their problem and not continue with the practice of pumping the watering into the well (yes, the well is located on their property, and yes they are aware that they have a link into my pond). They just do not give a toss.......

If it's broken then they are obliged to mend it, surely? Look at Useful Links/Property where there's a section on fosses septiques. If polluted water is going into a well it presumably could pollute much more than your pond, and potentially be a health hazard if it's anywhere near where your local tap water supply comes from. For example, out tap water comes from springs in the hills above the village and farmers are banned from allowing cattle to graze anywhere near the springs because of the pollution potential. I would talk to the mairie and also to SPANC.Tell them what's happening and ask them to act.