We are looking to buy a rainwater tank which we can also fill with springwater to drink. We have a very narrow alley on the side of our house so the tank measurement in depth/width should not exceed 500 to 600mm max. Length and height measurements are not a problem although it would help if its not too high to fill it from the top with collected spring water. Does anyone know where we can buy a rectangular tank preferably 1000 litre capacity?