Natural and eco-friendly sewage treatment

Posted on: 9th February, 2015

Category: Home, Garden & Environment

Contributor: West Cork People

Anybody wanting to build or renovate their home in an eco-friendly way has lots of opportunities, challenges and decisions. We all want to do the right thing, but making the right decision for the environment can sometimes be a balancing act. How we treat our septic tank effluent is just one of many choices ahead. But it's an important one. It's surprisingly easy to cause water pollution — but fortunately it's quite straightforward to prevent it too.

By Féidhlim Harty

The national septic tank inspection plan has now been rolled out around the country. Existing homeowners and those facing into a new building project are all more aware of the importance of protecting the local environment, as well as meeting regulations. So what are the options available?

The most straightforward option is actually a well-functioning septic tank and percolation system. Where soil depths and site conditions are appropriate, this option provides good settlement in the tank and good biological filtration within the percolation trench. Disposal of treated effluent is to the groundwater beneath. However, where soils are thin, heavy or waterlogged, this option ceases to offer good biological filtration, and water pollution is likely.

So in such cases, what are our plan B options? If you have a small garden and want to minimise on space use, then a mechanical treatment unit may well be a good solution. These provide both the settlement and the biological treatment within a septic tank type chamber using pumps and blowers to diffuse air into the effluent.

If you have a little more space — about half an acre of garden will suffice — then you may want a more eco-friendly approach and use a gravel reed bed system. A septic tank provides the settlement, and the gravel reed bed provides the biological filtration. One amazing feature of wetland plants is that they draw oxygen down to the roots, where it can support the same aerobic bacteria as in mechanical treatment. Thus your system can have a lower carbon footprint, and no electricity bills.

For a more natural approach again, you could choose a soil-based constructed wetland system. Instead of treatment taking place in the gravel, this shallow marsh-type system provides treatment around the stems and leaf litter of the wetland plants. Wetland birds love this system. I’ve seen moorhens, mallard, herons and snipe all hanging out within or around treatment wetlands, adding life and beauty. On heavy clay subsoil you won’t even need the plastic liner that is necessary for gravel reed beds. Overall, this can be the most cost-effective approach for sites with heavy soil.

If minimising the carbon footprint of your building project is your main priority, then the obvious thing is to close a loop on your sewage treatment and use it as fertiliser for your firewood. In this way, your sewage treatment system can become a source of fuel to offset oil imports, and can actually reduce the overall carbon footprint for your household. In a climate conscious world, switching like this from net carbon outputs to net carbon uptake is one of the most practical steps we can take towards a healthier planet.

Willows love moist, nutrient rich soils. This makes them ideal for sewage treatment. I’ve used them for willow filters and zero discharge willow facilities. The willow filters (a row or two of willows, often on a boundary) should be down-gradient of percolation areas — far enough that they don’t clog the pipes and close enough that they take up nitrates and phosphates migrating through the subsoil. As the layout suggests, the cost can be close to nil.

Zero discharge willow facilities on the other hand cost quite a bit more than any of the systems already mentioned. These are large, lined, soil-filled basins, planted with quick growing willow cultivars. Their distinct advantage is that they either store or evaporate 100 per cent of the septic tank effluent pumped into them. Thus there is no risk of pollution to groundwater or surface water, and firewood growth can be exceptional.

Although willows are mentioned in the EPA Code of Practice, there are currently no national guidelines on willow filter or zero discharge willow facility construction. The EPA Code is the main government reference document on domestic treatment systems, and is free to download from the EPA website. Nonetheless, because willows do such an effective job at mopping up moisture and nutrients, they are an invaluable tool, particularly on existing problem sites where a practical solution is needed.

Dry toilets are another option that are high on the eco-index; saving water, nutrients and biomass and preventing water pollution. Scandinavian countries use hybrid systems that use modified flush toilets or in-pipe systems to separate out urine and faecal solids respectively into fertiliser and compost, leaving relatively clean effluent to be treated. Urine has just the right mix of nutrients for growing plants and was traditionally used as a clean and safe fertiliser. One to ponder next time you sit on a loo seat and think!

Féidhlim Harty is the author of Septic Tank Options and Alternatives – Your Guide to Conventional, Natural and Eco-friendly Methods and Technologies. See for more information on the above options and EPA Code of Practice download. 

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This Saturday the 10th March, will see some magically curious activity as local Bandon national schools compete in a Wizarding Harry Potter Quiz. The prize will be the beautiful Bandon Banshee Perpetual Cup.

As any Harry Potter enthusiast knows, Bandon has the unique honour of having a character named after the town. The Bandon Banshee, was referred to as the nemesis of Gilderoy Lockhart in the Chamber of Secrets. The book grossed €60 million in sales and was the 7th highest earning film of all time.

Locals, looking to enhance the town for young people, saw the quiz as an ideal way promote the connection. The universally absorbing book series brings young readers on a huge adventure of magic, adversity and triumph. It is also an exploration of loyalty and friendship, good and evil – so it is not only popular way to engage young people, it is a hugely positive connection.

Zoe Tennyson, one of the organisers said they were delighted with the response from schools who ran a qualifying quiz as part of World Book Day. On Saturday Bandon Town Hall will be transformed into Hogwarts Great Hall, with proceeds going Bandon Playground Group, and to cover costs of the event.

Bandon Books will be rewarding the winning team with vouchers to each of the five members. The Bandon Banshee, or Bean-sidhe na Bandaan Perpetual Cup will be hotly contested – but which school will the Banshee go to??

If you have any questions please call Marguerite McQuaid on 087 900 9494
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8th March, 2018  ·  

Ballineen Foróige Young Engineers Exhibition 23 February 2018

The inaugural Ballineen Foróige Young Engineers Exhibition will take place in Gort Mhuire Hall in Ballineen this Friday 23rd February. As part of Engineers Week 2018, leaders and members of Ballineen Foróige Club have organised an exhibition which will showcase a diverse and exciting range of engineering projects that have been undertaken by members of the club over the last few weeks, with the aid of leaders and a number of local engineers.

With the aid of local pharmaceutical company Eli Lilly, along with the support of STEAM Education, a UCC based company focused on promoting science, technology, engineering, arts, and maths subjects in primary schools, Ballineen Foróige has been engaging members and leaders in all things engineering over the last six weeks. From researching, designing, and prototyping a project based on local problems, to participating in various workshops on coding and careers in engineering, Ballineen Foróige have been extremely busy in preparation for the exhibition this coming Friday night.

On the night itself, Michael Loftus, Head of Engineering at CIT, Fintan Goold, Manager at Eli Lilly and All-Ireland Cork winning Footballer, along with Geraldine Coughlan of GCA Architects & Designers, a local business, will act as judges on the night, evaluating the different engineering projects and offering some advice to the members of the club. Also in attendance will be the CEO of Foróige Seán Campbell, along with a number of local councillors, TD’s and Senators.

Leading the team of Ballineen Foróige leaders organising the event, is Rebecca Dwyer, a bioprocess engineer at Eli Lilly. Rebecca recently became a leader in the club and says that Ballineen Foróige Young Engineer Exhibition 2018 “promises to be a fun, challenging and rewarding experience for all involved and we look forward to welcoming parents, relatives, friends and members of the public to the exhibition and film screening on the evening of Friday 23rd February.” Overall, there are twelve projects entered in the exhibition. One project, led by Cian Kennefick and Charlie Nolan, members of the starting out club, examines the possibility of installing speed ramps on the road near local primary school. Fourteen-year-old Charlie says he got involved in the project as it was something to do and it gets you thinking. Cian says the most exciting part of the project was the building of the prototypes.

Both Cian and Charlie, along with thirty other members of the club will display their projects this coming Friday 23 February in Gort Mhuire Hall in Ballineen. Doors open at 8pm and the event runs until 10pm. All are welcome to attend, and admission is free. Catering, including tea and coffee, will be provided on the night.
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20th February, 2018  ·  

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Main course

17th February, 2018  ·  

Check out this new upbeat indie-folk track Edges, released today from Inni-K with a video by Myles O'Reilly. Inni-K will be performing at Levis’, Ballydehob on Saturday 24th February, with support from Sam Clague.
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16th February, 2018  ·  

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