New Research Theme Underway: New paper on Peat Filtration

There are many domestic treatment systems available but little real treatment data on existing systems carried out independently.    So our new research theme asks the question: How good are small-scale biological treatment systems?

Most studies on treatment systems have been done immediately post commissioning leading to over expectations of systems and generally poor performance evaluation which could result in long term environmental problems.

So just how well do these systems work?  The first paper in this series has just been published jointly with John Coady and there are 50 free downloads for the paper which became available online on September 3^rd 2014. Link:http://www.tandfonline.com/eprint/4E8eHpEkAB7T2Wjz4UPW/full

The full reference is:

N.F. Gray and  J. Coady (2014): Evaluation of full-scale vertical peat biofilters for treatment of septic tank effluents, International Journal of Environmental Studies, DOI:  10.1080/00207233.2014.954819

Septic tank charges and community advisory groups

A letter dropped through my letter box yesterday from Wicklow Council inviting me to register my household wastewater treatment system (if I have one) before February 1st, 2013. By last Friday only 2,500 households had registered their septic tanks. This is a huge disappointment to the Irish Government who had hoped that their €5 early registration fee incentive for early, set to end on the 28th of this month when the normal fee of €50 euro will come into force, would see the majority of systems registered. According to the CSO there are 497,281 septic tanks and household treatment units in the country, but this is probably a huge underestimation when holiday homes and more isolated dwellings are taken into account. Rural people are very concerned that the follow up inspections will force them into huge investments, with the added worry of unscrupulous individuals selling unnecessary upgrades and package systems to the unsuspecting owners, especially elderly who are most vulnerable in rural areas. My advice is to get registered now at the reduced rate and save yourself €45 as it is inevitable that all tanks will eventually be traced through ESB connections etc. The best approach to the inspections is to form community advisory groups to follow up on inspection reports and to help locals get the best advice and price on upgrades where necessary

Septic Tank Inspections Start in Six Months Time

Inspections of septic tanks and small household systems will commence in February 2013. The performance standards, essentially that they do not cause a risk to human health or the environment, are explained in the Water Services Acts 2007 and 2012 (Domestic Waste Water Treatment Systems) Regulations 2012. (Link). For the first time regulations have been set for the operation and maintenance of systems including frequency of de-sludging.

There will be some complex issues arising, one will be odours. The problem is that if the tank is properly vented then odours will be released either at the tank level or at the sewer vent at the roof top…so odour generation becomes a complex issue of wind direction, speed and temperature. The crust formation on the tank does reduce odours but with more frequent desludging and less scum developing due to greater detergent use and less use of heavy fats and oils…then crust formation is slower to form and less developed leading to odour release. To quote from the department of the Environment webpage: ‘There is no question of imposing modern standards, for example those set out in the EPA’s 2009 Code of Practice, to older systems. Nor is there any question of householders having to acquire additional land to facilitate remediation work. Where an on-site system fails an inspection, the 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’.

Septic Tank Registration Underway

At last it appears that hosueholders are now able to regitsre their septic tanks and household treatment systems which is a requirement under the The Water Services (Amendment) Act 2012. As we are repeatedly told that this is being done to address the European Court of Justice ruling against Ireland in October 2009. Of course it is also a sensible provision to protect public health and the environment.
Registration is covered by Domestic Waste Water Treatment Systems (Registration) Regulations 2012 and can be done online via the Protect Our Water website.  Alternatively applications can be made by post using forms available from public libraries and local authorities.

As an incentive the normal registration fee of €50 will be set at €5 until 28 September 2012. Registration must be completed on or before 1 February 2013. There will be no separate inspection charge.

Confusion Reigns Over Septic Tank Registration

County Councils throughout Ireland have been inundated with enquiries relating to how to register their home wastewater treatment systems. The best they have been able to do is to redirect enquiries to the Department of the Environment, Community and Local Government. The situation has become quite confused and much of the good will that was out there appears to be evaporating very quickly. The Government needs to clearly set out a proper timescale and mechanism for registration so that those who have septic tank and home treatment systems know what to do.  

The environ.ie website has some good advice to householders, which will form part of the new standards, that will help them prepare for inspections that are due to begin in 2013:

• Know where your tank is located;
• Visually examine your tank every year;
• Ensure only domestic waste water is treated in your tank;
• Ensure your tank only discharges from those points for which it was designed to discharge from;
• Ensure the effluent is not discharged to or does not rise to the surface of the ground;
• Ensure your tank is not discharging into streams/ditches;
• Desludge your tank when necessary, using an authorised waste collector;
• Ensure that your tank is not polluting and operation and maintenance is in compliance with the manufacturer’s manual, as appropriate.

More information at link.

Cheap Septic Tank Registration Offer

The pressure on rural householders to register their septic tanks has been increased by Minister for Environment Phil Hogan by offering a reduced septic tank inspection fee of €5 if they register within the first three months of the new scheme rather than the standard €50 fee .  However, little or no information has been made to householders about how to register, leading to confusion. 

The Water Services (Amendment) Bill Passed in Dáil

The Water Services (Amendment) Bill, which introduces the charge to householders for the inspection of their septic tanks has been passed in the Dáil by 76 votes to 34 with the €50 fee was written into the legislation.  The Government have been very careful to reassure the public that the fee will not be increased, however, it is the potential costs of upgrading and replacement which is primary concern for rural householders rather than a one off or annual registration fee.

Willows for wastewater treatment



On of many infected and dead willows



Infected willow now completely dead

Infected plant showing signs of die back

Healthy plant



There is much interest in the use of willows as part of the treatment sequence for single houses.  I have planted a small stand of the Common Osier Salix viminalis around the base of the percolation area from my septic tank. The objective is to encourage evapotranspiration during summer and to provide a barrier between the treatment area and the boundary of my property.  The stand is now about eight years old and last year many of the trees began to show signs of infection.  This year the infection (fungal) has spread and about a third of the trees have now died. Although I have replanted, I am concerned that this infection will spread. Has anyone else come across this problem?

Dangerous gases from Septic Tanks

A number of people have emailed me concerning fumes from septic tanks.  The problem with all stored organic wastewaters that go anaerobic is that large quantities of hydrogen sulphide and methane will be produced.  These gases are much heavier than air and displace the air within the tank, so once opened, the gas will rise from the tank and form a dense layer around the manhole at ground level. Hydrogen sulphide is very dangerous and as I said earlier odourless at high (lethal) concentrations so there is always a potential problem.  The key thing here is to ensure that all septic tanks are cross vented.   Cesspools or sealed septic tanks are highly dangerous in this regard.  The most dangerous scenario is where the tank is in a hollow or the entrance is contained in a riser or in a building so that the gas can build up. Never climb into a tank which has only been partially emptied unless you are sure it has been vented with air.  Most complete treatment systems such as the Biocycle are continuously vented via the aeration system, so that such gases should not build up.  However, if you are working in this area, and some of you who emailed me are, you should always have a gas detector.  It is worth the investment.  For more information see Link and more safety information see Link.

Fumes from stored sewage claims life

The sad new that one man has died and a second has been taken to hospital when they were overcome by fumes while emptying a commercial septic tank in East Cork has reminded us all of the dangers of working with stored sewage.  Always be aware of the danger of fumes when working alongside or inside tanks and chambers, over open manholes and in all enclosed spaces where sewage, sludge or slurry is present. Please remember always to be vigilant and carry a gas detector unit with you. Hydrogen sulphide can render you unconscious in seconds and is undetectable at lethal concentrations.

Septic Tank Design in the United States

My undergraduates are looking at small scale treatment systems this week and here is a very interesting video looking at the design of  aUS septic tank system which gives us an interesting comparison with our own systems here in Ireland.

Inspecting Septic Tanks

New regulations coming into place next year will require all septic tank systems in Ireland to be inspected.  Here is a interesting video from the US looking at some problems associated with tank assessment.

Septic tanks and on-site treatment systems to be monitored and inspected

The European Court of Justice ruling in October 2009 in relation to Irish on-site wastewater treatment systems, which of course includes the much maligned septic tank, will require new legislation in order to achieve the level of compliance required by the EU. Currently this is being prepared by the various State Agencies. What this will mean to the average householder with an on-site system is yet to be seen. However, it appears inevitable that the legislation will include prescribed standards covering both the operation and performance of systems. For these to be enforced then licensing, monitoring and inspection of systems will be required. What this will mean is that householders will have to become much more hands-on with their systems or pay someone else to look after them. Where systems fail standards then remedial action will be necessary.

Personally I am worried that this will lead to much hardship for many rural people and even in extreme cases the possibility of people unable to continue to live in their homes. Currently it costs about €5,000 to install a simple septic tank percolation area and approximately €18,000 for a sophisticated on-site treatment and percolation system. On top of this is the annual desludging costs of between €180-275. There are also possible maintenance or service charges for on-site treatment plants which range between €250 to €500 and which usually excludes the cost of replacement parts. To include a possible annual licence fee for on-site systems and then an equivalent monitoring and inspection system to the National Car Testing scheme with possible costly remediation or up grading work after inspection will create enormous hardship for many. I often wonder if there is an urban-rural divide in Ireland, in terms of water and wastewater provision there certainly appears to be.