Westmeath County Council is asking the public to get in touch with any information they might have.
A "particularly bad" incident of dumping at a midlands lake is under investigation.
Households items, including a large number of soiled nappies, were littered at Sailor’s Garden along Lough Sheelin earlier this month.
Westmeath County Council says the rubbish caused risk to the nearby wildlife and the general public.
It also says the clean-up will be costly, and will divert funds from other essential services provided by the local authority.
Staff went through the litter by hand in a bid to find those responsible, which it says was deeply unpleasant and a health risk for those involved.
Anyone with any information is being asked to contact the Environment Department at Westmeath County Council.
Prison Dispute Linked To Fatal Arson Attack In Offaly
BnM Opens New Funding Round For Offaly Community Benefit Fund
Orange Wind Alerts Issued As Storm Bram Approaches
Irish Hauliers Threaten Protests Over Toll Discount Dispute
Former Irish Soccer Legend Backs Offaly Community After Arson Attack
Tributes Paid To Former Fine Gael Midlands Politician
Midlands 103 Launches Joint Christmas Appeal With Simon Community
Offaly Arson Attack Is An Attack On Society Itself - Taoiseach
Woman Facing Life In Prison After Double Midlands Murder
Housing Committee Chair Flags Cost Concerns Over Apartment Fire Safety Scheme
Justice Minister Wants People To Come Forward Over Offaly Arson Attack
New Report Warns Of “Poor Liquidity” As Ireland’s Housing Market Stalls
Laois TD Renews Calls For Updated Wind Farm Guidelines
Midlands Man Laid To Rest Today
Anti-Racism Funding Granted For Offaly And Westmeath Groups
Gardaí Begin Murder Investigation After Child And Woman Dies In Offaly House Fire
Ashling Murphy Murder "Wrongly Accused" Granted Bail Over Theft Charge
Young Boy And Woman Killed In Offaly House Fire
Laois Makeup Artist Warns Of Expired Suncream Dangers
Lynx and Wolves In Ireland Pose Minimal Threat - Offaly Biodiversity