I LIVE in Block 4 of Lam Tin Estate and am concerned about the frequent lack of salt-water supply to cisterns. For at least one week in every month, we have to use tap water to flush toilets and this is very wasteful. I dread to think how many cubic metres of water are wasted when one considers that this salt-water shortage affects the entire block. The Housing Authority says that the problem is due to a damaged salt-water pipe. I would be grateful if the relevant government department would examine the damage and make repairs. It should also undertake a routine check of the pipe every month. PHOEBE TONG Lam Tin