Monaghan County Council has dealt with four instances of dumped diesel waste residue so far in 2021.
At these four sites, around 7,000 kilograms of waste were removed.
The County Council provided the latest figures to The Irish Farmer's Journal, which have since been obtained by Northern Sound News.
12 incidents of diesel wash residue dumping occurred in the county in 2020, resulting in 41,000 kilograms of waste being collected.
While Monaghan County Council is not aware of any illegal laundering plants being uncovered this year, two illegal laundry plants were detected last year.
Monaghan Fire & Civil Protection attended an illegal laundering plant fire north of Oram village in February of last year, and in December Monaghan County Council staff assisted in the removal of around 6,800 kilograms of residue from a plant in Ardaghey.
