Last week An Bord Pleánala wrote to the applicants for the proposed Biogas plant in Gort seeking clarifications regarding its water supply requirements. The developers state that they will need 120,000 m³ (120 million litres) of water annually to run the plant and there are some major concerns over this.
Why is this important?
The Biogas proposal would have a significant impact on the water supply of Gort Town which already has a constrained capacity. An additional extraction of 120 million litres per year would break an already over-stretched infrastructure. In order to meet these Biogas demands, significant restrictions could be imposed on the Gort Town Water Supply on how we could use water domestically, in businesses as well as potentially constraining future planning potential.
120,000 m³ of water is 120 million litres, which is Croke Park flooded to a depth of 10 metres. This relates to an average of 328 m³/day.
Why does a Biogas plant consume so much water?
In order to get an optimum aerobic digestion process, feedstock (silage, slurry, food waste) needs to be the consistency of a wet-sludge. The applicants state that the proposed Biogas plant will need sludge with dry-mater content (DMC) of between 5% and 8%.
The proposal indicates that it will process 90,000 tonnes of feedstock, including 54,000 tonnes of silage, which has a very high dry-matter content (28%), and would need to be diluted 3-fold to achieve the ideal ratio. This means evert cubic metre of silage (0.77 tonnes) would need about 3000 litres of water to dilute it correctly. So even with silage alone this would be well over 120 million litres water/year, and not considering dilution of the remaining 36,000 tonnes of feedstock. Their estimation is therefore too low for the proposed development.
An important point to note is that the water consumption will not be flat and there will be peaks, mainly from when silage cutting happens from end of May to October. In these months the majority of this water requirement will be consumed.
What are the Biogas developers proposing?
That’s the thing – the developers have indicated that the need 120 million litres of water per year but have not clarified where they are getting if from or how much they need. They have indicated that they can store run-off water from the site in attenuation ponds but this will only cover.a fraction of the requirements at peak
This is a significant omission that we highlighted during our observations on the application and we are happy that An Bord Pleánala have asked for clarification.
What clarifications are the ABP looking for ?
An Bord Pleanala have rightly questioned the developers to confirm if the capacity of the existing water network is capable of providing their needs. They requested the following in a letter on 11th May 2022:
“Please provide a breakdown of the water supply source to be utilized at the proposed development, with the associated calculations which confirm the availability of water capacity t othee the state requirements of 120,000 cubic metres of liqour per annum.“
What is the capacity of the Gort Water Supply??
According to the EPA , 2,638 people are serviced by the Gort Public Water Supply (PWS). The water is sourced mainly from Gort River, supplemented with water from two boreholes.
According to Irish water, the Gort Water supply is constrained and will need improvements to meet growing demand in the next 10 years. The daily demand in 2019 for the Gort Water Supply was 1018 m³/day (~1 million litres) and the expected growth in demand over the next decade is an additional 26,000 litres/day. The water supply is so limited currently that this tiny increase, will require improvements to the network. If an increase of 26,000 litres/day will require a upgrade, what on earth will happen when the proposed Gort Biogas plant needs an extra 328,000 litres/day on top of this. This is a daily average over the year so in peak silage season the requirement could easily double to 650,000 litres/day.
What we can also see from the Irish Water Capacity Register is that currently, in dry summers the Gort Water supply is barely able to keep up with demand. The total capacity of the current water supply is 1,440,000 litres/day and the 2019 demand in summer was 1,407,000 litres/day, allowing only a tiny margin of headroom (33,000 litres/ day) .
The town’s water supply is currently at capacity and burdening the supply further will only result in one thing- water restrictions. So then granting access a massive water consuming plant to use this already highly constrained water network would be simply negligent.
What kinds of impact could this have?
The proposed Gort biogas plant would cause a breakdown of the water supply in normal years and in dry years would wreak havoc. Gort would simply run out of water at peak times.
We are currently 3 months in to a ‘boil notice’ period and are fully aware of the inconvenience and hardship this has brought to some. If the proposed Biogas plant goes ahead, we could easily see 3 months of water restrictions during peak times limiting how and when we use our home supply.
We also need to carefully consider and be fully aware of how this could impact future developments within the town. If the Biogas plant went ahead then it would be impossible to develop more housing because the water supply would not have the capacity.
There is also the environmental question,- what happens if we take an additional 650,000 litres /day from the Gort River? Will it stop flowing completely (like it almost did in 2018) ?
It’s simply not good enough that the proposed Gort Biogas plant could go ahead without due consideration to these matters. The developers omitted this consideration in their EIAR, we highlighted this on our observations and now An Bord Pleanala is seeking clarification.
The water capacity constraints are very real and so it’s is very unlikely that the Biogas developers will get any confirmation from Irish Water with demands of an additional 120 million litres of water per year day from a water supply that’s on the edge of collapse. We look forward to how the developers intend to address their response to the Bord and we will be ready to challenge it.
This is one of many reasons that this the Gort Biogas Plant can not go ahead. No ifs, no buts. This is a serious consideration, and one of many as equally serious, that could affect the people of this community and the future of the town.
Support is essential !
Please continue to support our fight against this development and share this information far and wide. If An Bord Pleanala allow this development to go ahead then we will need that support even more.
David Murray.