It was one of five counties to do so.
Westmeath was among five counties which didn't carry out its allocation of septic tank inspections last year.
It was required to complete seven inspections in 2023, but only managed two, according to a new report from the EPA.
However, Westmeath did repair 82% of its failing systems, while Offaly fixed 86%, putting both counties in the 'high rate' category.
Laois ranked in the 'moderate' category, having repaired only three quarters of its failing systems by the end of last year.
Noel Byrne from the EPA says some of the septic tanks hadn't been fixed in over a decade: