Almost 8,000 people in West Cumbria have joined a Facebook group in a bid to get United Utilities to address concerns about water quality.
Members of West Cumbria Water Supply (Save our Water Services) are calling for action following claims the change in water has left them with health problems.
United Utilities began blending soft water from Ennerdale with harder water from Egremont boreholes.
People say they've had upset stomachs, itchy skin, mouth ulcers, and have been forced to buy bottled water.
The water supplies many homes across West Cumbria, including Workington and Seaton.
A petition is being organised to force the water company to take concerns seriously and there has also been a call for a public inquiry into the situation.
United Utilities say that the water is safe, and met with concerned residents at drop-in sessions in July: