ALMOST 40pc of the country's septic tank owners – over 190,000 – have yet to register for the government charge, with just four days left to do so.
The environment department has confirmed the latest figures show that 295,183 registrations have been processed, with a further 10,000 written applications under consideration.
All septic tank owners have to register their system by Friday (February 1), or face possible fines of up to €5,000.
According to Census 2011, there are 497,000 domestic wastewater treatment systems. But just 61pc of the septic tank owners have so far agreed to pay the registration fee.
A spokesperson for the Department of Environment said the Local Government Management Agency (LGMA) has reported a significant increase in online registrations over the past few days.
Environment Minister Phil Hogan introduced a temporary low charge of €5 initially to get people to register, but that passed last September.
The remainder have to pay €50 per wastewater system by Friday.
Mr Hogan introduced an incentive last month whereby homes who register by Friday will be able to apply for a grant worth up to €4,000 to upgrade their systems.
The minister said grants would only be available to householders whose system had been inspected by a local authority and been found to need improvements.
A septic tank registration certificate is valid for five years.
Re-registration is necessary after five years as the first registration is intended to identify only the ownership and location of domestic wastewater treatment systems.
Jim Connolly of Rural Resettlement Ireland in Kilbaha, Kilrush, Co Clare, said last night that he had no intention of paying the €50 registration.
"The whole thing is ridiculous," he told the Irish Independent. "My main objection is that the grants will be means-tested and it is another layer of bureaucracy.
"This will be like the fiasco of people trying to apply for grants for third-level fees.
"What it really boils down to is more work for bureaucrats in local authorities.
"The registration only holds for five years – what is the point? It opens the door for more charges in five years' time."
The Government has warned that systems which have not been registered will be at increased risk of inspection.
A national inspection plan, being finalised by the Environmental Protection Agency, will begin later this year and will be undertaken by local authorities.
Anyone who has a property connected to a septic tank or other treatment system is liable for the €50 charge.
For more information, see www.protectourwater.ie.