The Environmental Protection Agency has expressed concern over the number of septic tanks failure in the region.
A 2019 report reveals that 72% of all systems inspected last year failed the test, with a failure rate of 62% in Leitrim.
According to the EPA, just over 40% of systems who failed the test between 2013-2019 in both counties were fixed.
Cavan's septic tank failure rate was 42% while Longford's failure rate from 15 inspections was 73%, but 100% of all failures between 2013 and 2019 had been fixed.
46% of all septic tanks in Monaghan failed the EPA test - with 84% reporting a fix rate. in the last six years.