Inspection of septic tanks and other domestic waste water treatment systems


A registration and inspection regime was introduced in 2012 for domestic waste water treatment systems, such as septic tanks. The regime aims to protect ground and surface water quality from the risks posed by systems that are not working properly. It was introduced under the Water Services (Amendment) Act 2012 and a related set of Regulations.



If you have a septic tank or similar system, you must register its details with your local authority and pay a registration fee. If you have already registered, you do not need to re-register. The requirement to re-register every five years has been removed from the legislation and your existing certificate remains valid.

The general deadline for registration was 1 February 2013, but you can still register if you have not yet done so - see 'How to apply' below. If you registered an existing system after the deadline, you will not be eligible for any grant if your system is found to need remedial work - see ‘Grants for remedial work' below.

New systems must be registered within 90 days of being connected. Replacements of previously registered systems do not have to be registered separately.

The Environmental Protection Agency (EPA) is responsible for developing national inspection plans and reporting on their implementation.


If you have a domestic waste water treatment system, you need to:

  • Know where your septic tank is located
  • Operate and maintain the system so it is fit for purpose and fully operational
  • Ensure that the system cannot pollute the environment by discharging or leaking waste anywhere it is not supposed to, that is, into the ground or any water source
  • Ensure that roof water or surface water run-off cannot enter a domestic waste water treatment system
  • De-sludge the system at intervals appropriate to the tank capacity and the number of people resident in the premises connected to it, or as recommended by the system’s manufacturer. De-sludging should be carried out by an authorised contractor. You should keep the receipt from the contractor for 5 years.

The leaflets What you need to know about your septic tank (pdf) and Is your well at risk from your septic tank? (pdf) provide useful information.


Local authorities arrange for inspections to be carried out. The inspectors are appointed and approved by the EPA. They have to carry identification and show it to householders on request.

Inspections started in 2013. They concentrate on areas with high risk to the environment and public health – where drinking water sources or habitats are at risk from waste water discharges. They are also being carried out in areas of lower risk, but at a lower rate. Your local authority will notify you if your system is to be inspected.

If the inspector finds that your system is working properly and being maintained correctly, you need take no extra action. Otherwise you will get an advisory notice from the local authority, requiring you to improve the maintenance of your system or to upgrade or remediate it. Any remediation work required will be based on factors such as the nature of the problem, the extent of risk to public health or the environment, existing site size and the hydrological and geological conditions present.

You can read more about What to expect from a septic tank inspection (pdf).

Grants for remedial work

If you need to carry out this type of work, you may be able to get a grant to help with the cost of the work required. The grant is means-tested. In order to be eligible, you must have registered by 1 February 2013 and you must have received an advisory notice from the local authority requiring you to have the work done. Routine maintenance work does not qualify for a grant.

See 'Rates' below for the income thresholds and grant rates. There is further detailed information about the grant on the application form, including a checklist of the documents required.


If you have a septic tank or similar domestic waste water treatment system, you already have a duty of care (under the Water Services Act 2007) to ensure that your treatment system does not cause a risk to human health or the environment or create a nuisance through odours. The 2012 Act adds to the existing duty of care provisions.

The EPA’s 2009 Code of Practice on waste water treatment systems for single houses sets out the most up-to-date standards. However, these are not being applied to older systems. The 2012 Regulations define performance standards, including maintenance and de-sludging requirements.


The once-off registration fee is €50.

There is no inspection charge.

The costs of any remediation will depend on the extent and nature of the work required.

The income thresholds and grant rates for assistance with remedial works are shown in the following table:

Household income Percentage of costs available Maximum grant
Up to €50,000 per year 80% €4,000
Between €50,001 and €75,000 50% €2,500
Over €75,000 0% No grant payable

How to apply


You can register your system online at

Alternatively, you can download a form (pdf), or request one from your local authority, library or Citizens Information Centre or by calling LoCall 1890 800 800. Your cheque, postal order or bank draft should be made payable to ‘Protect Our Water’.

You can post the application form and payment to Protect Our Water, PO Box 12204, Dublin 8, or else hand them in at your local authority office. Local authorities will also accept payment by credit card, debit card or cash.


To apply for a grant for remedial work, you can download the application form. Details of the grant scheme and how to apply are in the notes on the form.

Further information

The Department of Housing, Planning, Community and Local Government has published information on the legislation.

The Environmental Protection Agency has published a set of Frequently Asked Questions.

There is also a detailed set of FAQs on

You can contact your local authority or the Environmental Protection Agency for more information.

Page edited: 5 March 2020