Homeowners who identify major issues with their septic tanks are barred from availing of a grants scheme to fix the problem and protect water sources.
Only if the tank fails an inspection are local authorities allowed to provide up to €4,000 in financial aid, the Department of the Environment has confirmed.
This is despite some 500,000 septic tanks being dotted across the country, many of which are in high-risk areas and linked to pollution.
This is because they are not being emptied or properly maintained, but in many cases they also require replacement or structural repairs.
New figures show that just 65 grants have been paid in 2014 and 2015, totalling €206,000.
Most have been paid to homeowners in Meath, where 13 have been awarded; followed by seven each in Roscommon and Sligo and six each in Limerick and Clare.
Households with incomes of up to €50,000 can claim 80pc of the costs of carrying out works, to a maximum of €4,000.
For incomes between €50,001 and €75,000, 50pc can be claimed up to €2,500.
However, there has been sharp criticism of excluding households which identify a problem on their own initiative.
Fianna Fáil environment spokesman Barry Cowen said if the Government was serious about protecting water sources, it would be extended to all households. "In Offaly, where our water sources are underground, a bad septic tank is a major contributor to pollution," he said.
"The Environmental Protection Agency is expected to carry the can, one would assume, but they would not have the manpower or people on the ground to ensure standards are adhered to."
Some 497,281 septic tanks and other on-site wastewater treatment systems are located across the country. To date, some 454,464 systems have been registered, a 91.3pc compliance rate.
Households which failed to register their tanks by February 2013 are not eligible for the grant payment.
The Department of the Environment defended the decision to exclude registered, but not inspected, tanks.
It said the scheme was introduced to assist in repair costs for domestic wastewater treatment systems that were deemed, following inspection, as requiring repairs.