THE Metropolitan Waterworks and Sewerage System Regulatory Office (MWSS RO) issued a show cause order to Manila Water Co. Inc. and Maynilad Water Services Inc. over complaints on high water bills, the agency said on Wednesday.

In a statement, MWSS chief regulator Patrick Lester Ty said both concessionaires were asked to explain “the alarming number of complaints” the agency has received from their customers.