For either steel or plastic, volume ice = 1.10 * volume of water.
So for a 1 litre bottle, filling it 900 mL full of water should make 990 ML of ice or basically full without exerting extra pressure.
Even a 1L plastic bottle entirely full of water can break if you freeze it.
But really, basalt doesn't offer a lot of filtration. Springs in basalt = drinking untreated surface water.