Category: environment

Make a difference with us

At Code the City we believe that the right people, with the right skills and tools, can do great things. We believe that we can use technology and data to solve many civic challenges. Those beliefs are as applicable now as was when we started seven years ago. And our volunteers who come to our events time and again agree. They know that sharing their skills and knowledge with others in small teams, over a weekend, working on a focussed and achievable project, is a satisfying experience which leaves them with a sense of achievement. It also introduces them to working in teams and in an agile way: short sprints of work and pauses for review. 

“The power of one, if fearless and focussed, is formidable, but the power of many working together is better” –

Gloria Macapagal Arroyo

In the last seven years we’ve tackled many topics – and worked with multiple partner organisations in the public and private sector to solve their challenges – and to identify opportunities to use data and technology to improve how they deliver their services.

Throughout that period we’ve had some central principles that we’ve adopted which still hold true: 

  • Data, where appropriate, should be open and licensed for reuse
  • Software should be developed as open source – where the code can be inspected, and improved on by anyone, and reusable openly by others 
  • Information, images and other content should be as openly licensed as possible to encourage re-use and creativity
  • Where appropriate stable platforms exist (such as WIkidata, Open Streetmap, Github,or Wiki Commons) we should use those
  • People working in small teams and in short sprints of activity can achieve an enormous amount over a weekend

Last week at Open UK’s COP26 event “Open Technology for Sustainability”, which our co-founder and trustee Ian Watt attended, those same principles that inspired our creation, and inform our continuing work, were echoed time and again by speakers. And at the evening awards dinner we were runners-up to the the wonderful Open Knowledge Foundation, in the Data category. This further validates our belief in our approach. 

CTC’s Runner-up trophy for data in Open UK’s 2021 awards

More recently we’ve been concentrating even harder on improving open data in Scotland and the UK – but not to the exclusion of other projects. In addition to several history and heritage projects which have seen large amounts of open data created and published, we’ve had projects such as Open Wastemap which was built almost entirely over two CTC weekend and uses community-sourced data in Wikidata and OpenStreetmap to power this really useful tool to find local recycling facilities. 

Our next event CTC24 – Open In Practice is taking place in just over a week. It is the perfect introduction to what we do and to becoming involved. We already have a list of potential projects that attendees, new and experienced, can get involved in. Some of these are local in scale and some national. All need a blend of skills from attendees. You don’t need to be either a coder or data expert to participate. You can sign up directly here or from the event link above. 

No excuses: be part of the group that does the good things – or stand by and watch while we do!

Waste Wizards at CTC22

A write-up of progress at the March 2021 Environment-themed hack weekend.

What problem we were addressing?


The public have access to two free, easy accessible waste recycling and disposal methods. The first is “kerbside collection” where a bin lorry will drive close to almost every abode in the UK and crews will (in a variety of different ways) empty the various bins, receptacles, boxes and bags. The second is access to recycling centres, officially named Household Waste Recycling Centres (HWRCs) but more commonly known as the tip or the dump. These HWRCs are owned by councils or local authorities and the information about these is available on local government websites.


However, knowledge about this second option: the tips, the dumps, the HWRCs, is limited. One of the reasons for that is poor standardisation. Council A will label, map, or describe a centre one way; Council B will do it in a different way. There is a lot of perceived knowledge – “well everybody just looks at their council’s website, and everybody knows you can only use your council’s centres”. This is why at CTC22 we wanted to get all the data about HWRCs into a standard set format, and release it into the open for communities to keep it present and up to date. Then we’d use that data to produce a modern UI so that residents can actually get the information they require:

  • Which tips they can use?
  • When these dumps are open?
  • What can they take to these HWRCs?
  • “I have item x – where can I dispose of it?”

Our approach


There were six main tasks to complete:

  1. Get together a list of all the HWRCs in the UK
  2. Build an open data community page to be the centre point
  3. Bulk upload the HWRCs’ data to WikiData
  4. Manually enter the HWRCs into OpenStreetMap
  5. Create a website to show all the data
  6. Create a connection with OpenStreetMap so that users could use the website to update OSM.

What we built / did

All HWRCs are regulated by a nation’s environmental regulator:

  • For Scotland it is SEPA
  • For Northern Ireland it is NIEA
  • For Wales it is NRW
  • For England it is EA

A list of over 1,000 centres was collated from these four agencies. The data was of variable quality and inconsistent.


This information was added to a wiki page on Open Street Map – Household waste in the United Kingdom, along with some definitions to help the community navigate the overly complex nature of the waste industry.


From that the lists for Scotland, Wales and England were bulk uploaded to WikiData. The was achieved by processing the data in Jupiter Notebooks, from which formatted data was exported to be bulk uploaded via the Quick Statements tool. The NIEA dataset did not include geolocation information so future investigation will need to be done to add these before these too can be uploaded. A Wikidata query has been created to show progress on a map. At the time of writing 922 HWRCs are now in Wikidata.

Then the never-ending task of locating, updating, and committing the changes of each of the OSM locations was started.

To represent this data the team built a front-end UI with .NET Core and Leaflet.js that used Overpass Turbo to query OSM. Local Authority geolocation polygons were added to highlight the sites that a member of the public could access. By further querying the accepted waste streams the website is able to indicate which of those centres they can visit can accept the items they are wanting to recycle.

However, the tool is only as good as the data so to close the loop we added a “suggest a change” button that allowed users to post a note on that location on OpenStreetMap so the wider community can update that data.

We named the website OpenWasteMap and released it into the wild.

The github repo from CTC22 is open and available to access.

Pull requests are also welcome on the repo for OpenWasteMap.

What we will do next (or would do with more time/ funding etc)

The next task is to get all the data up-to-date and to keep it up to date; we are confident that we can do this because of the wonderful open data community. It would also be great if we could improve the current interface on the frontend for users to edit existing waste sites. Adding a single note to a map when suggesting a change could be replaced with an edit form with a list of fields we would like to see populated for HWRCs. Existing examples of excellent editing interfaces in the wild include healthsites.io which provides an element of gamification and completionism with a progress bar with how much data is populated for a particular location.

An example entry from Healthsites.io

Source: https://healthsites.io/map#!/locality/way/26794119

While working through the council websites it has become an issue that there is no standard set of terms for household items, and the list is not machine friendly. For example, a household fridge can be called:

  • Fridge
  • Fridge Freezer
  • WEEE
  • Large Domestic Electrical Appliance
  • Electric Appliance
  • White Good

A “fun” next task would be to come up with a taxonomy of terms that allows easier classification and understanding for both the user and the machine. Part of this would include matching “human readable” names to relevant OpenStreetMap tags. For example “glass” as an OSM tag would be “recycling:glass”


There are other waste sites that the public can used called Bring Banks / Recycling Points that are not run by Local Authorities that are more informal locations for recycling – these too should be added but there needs to be some consideration on how this information is maintained as their number could be tenfold that of HWRCs.

As we look into the future we must also anticipate the volume of data we may be able to get out of sources like OpenStreetMap and WikiData once well populated by the community. Starting out with a response time of mere milliseconds when querying a dozen points you created in a hackathon is a great start; but as a project grows the data size can spiral into megabytes and response times into seconds. With around 1,000 recycling centres in the UK and thousands more of the aforementioned Bring Banks this could be a lot of data to handle and serve up to the public in a presentable manner.