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Urban food waste disposal initiative Gillian Brady & St John Walsh April 2019 Research funded by Local Agenda 21 Grant

About the Authors

Based in the city centre Gillian & St. John are award winning architects interested in how design can improve the built environment and help create sustainable urban communities. They are interested in helping public bodies and councils achieve their ambitions and goals through analysis and design. To date, this has taken the form of workshop facilitation, the organisation of community based events and collaboration with public bodies on a range of projects in both the UK and Ireland.




Introduction 4 Key Facts 5 Wormery Set-up 6 Harvesting Compost 8 General Tips 9 Advantages & Disadvantages


Conclusion & Suggested Next Steps


Bibliography 13




There are many dwellings in Dublin’s historic centre which do not have the option of a brown bin collection service for food waste due to the city’s tight urban grain. Faced with this issue when we moved from Dublin 04 to Dublin 08 in March 2018, we decided to start composting our own food waste rather than sending it to landfill. Through research at the outset, we deduced that a wormery would be the most appropriate composting option for us given our lack of garden waste and restricted amount of outdoor space. This report, documenting the process of establishing a wormery in the rear yard of our cottage in the Liberties over the course of a 1-year period, aims to increase awareness and understanding as well as establish the feasibility of this method of urban food waste disposal. We have found the wormery to be a great success; reducing our general waste output by almost 50% and in the process, producing almost 30 litres of high quality compost over an initial 12 months. We hope that this report will act as a useful case study on the subject matter and lead to a wider roll out of wormeries across the city centre and beyond.

Blue general waste bags gather weekly beneath the trees in urban squares for collection URBAN FOOD WASTE DISPOSAL INITIATIVE


Key Facts

House type: 1-bedroom cottage in the city centre dating from 1890s set around a square Private external amenity space: Private rear back yard, 7 sqm No. of persons in household: 2 adults Diet: Vegetable, dairy & fish based Wormery type: 75 litre, 3-tray wormery purchased online at www.wormcity.co.uk for ÂŁ67 Date of wormery set up: 20.04.18 Time taken to produce first tray of compost: 9-months Quantity of compost produced over 1-year period: 2 x 1o litre buckets (& a further 25 litres in progress)

Potential amount of compost produced over the course of 1-year



Wormery Set-up On 20.04.18 we set up our wormery. As we purchased it online, the date of set-up was dictated by when the product arrived to prevent the worms from dying. The below description gives an overview of the process.

Equipment provided - plastic shelves, coir, worm feed & worms

Additional requirements - corrugated cardboard, newspaper, water, small amount regular compost

Step 01 - Cut corrugated cardboard to size of tray

Step 02 - Add water to coir & allow to expand

Step 03 - Add coir above cardboard

Step 04 - Add small amount of pre-existing compost

Step 05 - Add worms



Wormery Set-up

Step 07 - Shred newspaper & soak

Step 08 - Add shredded, damp newspaper

Step 09 - Add more corrugated card & lid

Allow worms to settle into their new home for 2 weeks

Gradually begin to feed worms, a little at a time

Add shredded newspaper frequently to ensure a layer remains on top of the food to keep away flies.

A note on general maintenance requirements: Although not time consuming or difficult, dedication is required to ensure the wormery functions correctly. Tasks include adding food waste incrementally (we do so daily), adding shredded newspaper (twice weekly) and aerating all trays (fortnightly). When the top tray is full, add a new tray above (in our case, this was 4-months post-establishment). The worms will travel up to the new food. URBAN FOOD WASTE DISPOSAL INITIATIVE


Harvesting Compost

When all the trays are full it is time to harvest compost from the lowest tray. In our case, we harvested the first on 23.01.19 i.e. 9 months post-establishment. Decanting of compost is a relatively slow process as care is required to avoid undue loss of worms. We recommend that compost is removed with a small implement, reducing the topmost layer gradually, as the worms will travel down from the bottom tray to the sump (if left in place) to avoid the sunlight. These worms can then be added into the top layer once all the compost has been transferred.

Appearance of compost in bottom tray when ready for harvesting

Spooning of compost in progress

Our first bucket of compost

Harvesting process underway with bottom tray to LHS & top tray to RHS of photograph



General Tips Through trial and error we have honed our methodology for dealing with the worms and included some useful tips below.

Flooding: On one occasion the bottom tray became water logged. This was resolved quickly through draining however to prevent future such incidents we now leave the sump tap open at all times.

Liquid: We find it useful to collect this liquid in a container. It makes great natural fertiliser for our plants.

Storing food waste: We have found that a 1kg yoghurt tub makes the perfect sized vessel for storing food waste in the kitchen. We generally decant this into the wormery once or twice per day.

Protection from flies: Shredded newspaper & recycled cardboard, such as pizza boxes, help to ensure that flies are kept at bay.

Aeration: To ensure a healthy flow of air and movement of worms, all trays need to be agitated frequently. We try to do so every 2-weeks and have set aside a kitchen fork for the process.

Reducing moisture buildup: To aid drainage, we have found it useful to prop the wormery at an angle using terracotta plant pot feet.



General Tips

Compost appearance: The LHS photo illustrates what the compost looks like at the point it is ready for transfer from middle to bottom tray while the RHS photo shows what the compost looks like at point of transfer from the top to the middle tray.

Compost Use: As the compost is very rich in nutrients, it is recommended for use along side regular compost. We have found it works well when added as a top dressing as per LHS photograph. We have also planted seeds in the compost (without mixing with other soil) and to date this is working well as shown in the RHS photo.



Advantages & Disadvantages


ADVANTAGES Feasibility •

Very small amount of space required (0.5 metre squared).


Accepts the majority of food types.

Unlike other composting options, green garden waste is not required.

Suitable for use indoors (due to the open plan layout of our house, we did not trial this).

Regular maintenance required.

At the time of purchasing our wormery, there were no providers to be found in Dublin.

Meat products are compatible however, in the context of the city centre we chose not to add this to the wormery due to the risk of attracting vermin.

Not all food waste can be added to the wormery. Only small amounts of garlic, onion and citrus fruit skins can be added. We have found this to be the main dis-advantage as we eat citrus fruit daily.

Environmental •

Reduces household waste output by approximately half.

Waste is dealt with locally, eliminating reliance on transport for removal from city centre.

Economy •

Low start up costs (£67 in our case).

Eliminates requirement to pay for brown bin collection or reduces the general bin collection frequency by 50%.1

Produces useful bi-products including high quality compost & concentrated liquid fertiliser.

1 Costs for one bin collection service provider in city centre at the time of writing were €16.50 per month for 2 collections of each bin, including black, green & brown or €9 per month service charge plus €3.60 per bin lift. According to the EPA, ‘each year food waste costs the average household up to €1,000’ (http://www. epa.ie/pubs/reports/indicators/epa_factsheet_waste_v2.pdf).



Conclusions & Suggested Next Steps

The use of a wormery as a sustainable means of disposing of food waste has proven to be very successful for us, a small household with limited outdoor amenity space in Dublin city centre. With little start up costs and minimal maintenance, the wormery has reduced our bin waste by almost 50% and provided us with an abundance of high quality compost.

We hope that this case study will act as inspiration for the establishment of many more wormeries. We would welcome the opportunity to meet to discuss our finding and look forward to any comments or queries you may have regarding this or potential participation in the next phase of the project.

Through conversations with friends, neighbours and colleagues, we have found that wormeries are not widely used by those living in Dublin, mainly due to a lack of awareness. Our suggested next steps aim to firstly create awareness and understanding of wormeries and secondly the provision of training and support to interested parties. 1. Creating awareness: Surprisingly few individuals in our experience are familiar with the use of wormeries to sustainably deal with food waste. We would therefore suggest and hope that a portion of this report would be made widely available and perhaps supplemented with an article in a Dublin based newspaper for example the Dublin Inquirer. 2. Wormery roll out: From an opinion piece by Ciaran O’Byrne entitled ‘A Quick Guide to City Composting’ in the Dublin Inquirer, we became aware of an initiative run by the French government in 2018 whereby, they gave away approximately 1,500 wormeries to interested Paris residents. Although at the outset, we had hoped that the wormery could become a community based activity, upon reflection and through experience, we feel that it is likely to be most effective for use at the scale of the household due to the level of control and management required. As a result, we would suggest that an initiative such as the above could be implemented on a smaller scale to perhaps initially 5-10. Important factors to consider would be the selection of suitable interested parties along with the provision of training and support. Other organisations which may be willing to assist with further scale ups are DCC Beta and Smart Dublin. We have sent a suggestion on this to DCC Beta and await a response.

Wormery shown in context of rear yard (adjacent to BBQ).




Dublin Inquirer 01.08.18 ‘Ciaran: A Quick Guide to City Composting’ by Ciaran O’Byrne p.37 www.wormcity.co.uk www.envocare.co.uk www.stopfoodwaste.ie/resource/wormeries/

Note: All photographs are authors own.




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Urban Food Waste Report  

There are many dwellings in Dublin’s historic centre which do not have the option of a brown bin collection service for food waste due to th...

Urban Food Waste Report  

There are many dwellings in Dublin’s historic centre which do not have the option of a brown bin collection service for food waste due to th...