35 group water schemes supply quality water to 50,000 people in Cavan and Monaghan.
This is according to Barry Deane, CEO of the National Federation of Group Water Schemes (NFGWS) who spoke to Shannonside Northernsound following the EPA's latest report which was published yesterday.
It highlighted how THM levels - the by-product of the chlorine disinfection process - were high in some parts of Co Cavan.
Mr Deane, meanwhile, says that the vast majority of water in group water schemes meets the required standards.
But he also admitted that "there are difficulties" around THMs in some supplies locally.
The NFGWS CEO said that Cavan and Monaghan Co Councils continued to work "very hard" to sort these problems out.