What if aggregate could be manufactured instead - using 98% waste?

Now it can. Novagg, "hailed as the world’s greenest lightweight aggregate", is made using unsorted mixed coloured waste glass combined with other industrial waste. Developed in collaboration with Imperial College, "work is now under way with several multi-national companies to put Novagg on the commercial stage in a bid to become the global ‘green’ construction material of choice".

This is just the sort of advance that makes forecasting aggregate shortfalls over the next 20 years so uncertain, and will in time reduce the need for the sort of quarry AI is planning at Straitgate Farm.

Of course, AI will know all about these advances. It will know that this is the way its industry has to move. It will know that consuming farmland on this ever more populated island is not sustainable. And, as if to prove as much, in 2010 AI bought a majority stake in a company using fly ash to make lightweight aggregate. Lytag "provides an excellent alternative to natural, quarried aggregate, being strong, light and consistent". AI's then CEO (now Chairman) said "as modern construction continues to evolve, fly-ash and Lytag are increasingly being used and specified for a range of products and projects". A new "state of the art facility" next to Drax Power Station will be finished this summer and will "displace the need for 400,000 tonnes a year of newly quarried aggregates".

So, DCC's Minerals Plan to 2031 should acknowledge the advances being made in construction materials and the long term decline of sand and gravel, not allocate more and more land for quarrying. Products such as Novagg and Lytag reduce the need for aggregate extraction, divert material from landfill and preserve the natural landscape - to not use them more widely would appear a no-brainer.

Construction industry ‘faces 10 more years of pain’

Construction output in the three months to November was "down 9.8%" on the same period in 2011. Furthermore the BBC reports on an industry lobby group that "doesn't anticipate the industry returning to its former levels until at least 2022". Something DCC should bear in mind when forecasting aggregate shortfalls for the years ahead.

Hanson on the other hand is mothballing quarries

Whilst AI is busily planning to dig up East Devon farmland and open a new quarry at Straitgate, Hanson is taking a different line - mothballing quarries, closing plants and laying off workers, expecting business in 2013 to be even worse.

With construction and aggregate demand still contracting, and no sign of recovery on the horizon, DCC can robustly make the case - having 9 million tonnes of sand and gravel already with planning permission, enough for 20 years at current rates - that no further provision is needed for its new Minerals Plan. In any case, for a Plan that runs as far into the future as 2031, and in order to appease mineral operators, provision can always be made for the Council to monitor production and reserves, and make site allocations when shortfalls actually become apparent, not according to a fallible long-range forecast.

After all, how many millions of tonnes would DCC have allocated needlessly if it had made the Plan in 1990, for example, when production was almost four times higher than it is today, or in 1968 at the time Straitgate was the subject of a Public Inquiry? Building techniques, materials and demands have changed, and therefore the Council needs to remain flexible, and encourage movement away from the unsustainability of primary aggregates.

'Mountains' of sand stockpiled at Blackhill Quarry, Woodbury Common SAC, SPA, SSSI, AONB

If Devon had relied on the forecasts of 1968...

How much faith should we have in forecasts? ECC (now Aggregate Industries) based their planning application to quarry over 800 acres of East Devon in 1968 on forecasts. Now in 2012 DCC has decided it needs to identify new sites for future sand and gravel quarrying, again on the basis of a forecast, which has identified a shortfall of reserves some time over the next 20 years. 

The Public Inquiry of 1968, deciding the fate of those 800 acres, heard a number of forecasts, and now with the benefit of hindsight we can see how accurate they were. ECC's submission to the Inquiry forecast that "58)...the demand from the two complexes in the year 2000 will be 2.42 million tons, made up of 1.23 for Blackhill and 1.19 for Rockbeare. This is based on a probable increase between 1966 and 1980 of 6.3% per year, following the official forecast rate of increase, and an increase of 4.5% between 1980 and the year 2000, based on official forecast population increases for the South West". The Planning Authority challenged this forecast, and thought "it should be 2.11 million tons". In the year 2000 the actual figure for Devon turned out to be only 0.8 million tonnes, or just 33% of the forecast; in 2011 it was even lower at 0.44 million tonnes or 18%. Their submission also maintained that "55) Nationally, the production of sand and gravel increased annually between 1958 and 1966, from 60 to 100 million tons, and the forecast for 1980 is 215 million tons." The actual national figure in 1980 was less than 100 million tonnes, or 45% of forecast.

Mr. Douglas Frank QC, acting for the Devon River Authority, East Devon Water Board and others, challenged these forecasts, "348) It is contended that no decision should be taken in the absence of a full investigation, to avoid another "Stanstead" case. The company have assessed future need far in excess of any normal period for making forecasts of demand, and on the theoretical basis of population estimates, which are noted for their inaccuracy. This may be inevitable in the case of development plans, or planning water resources, but they do not look 60 years ahead and population figures should not be relied on for a long period. It is equally dangerous to relate population to production in the past. 349) Who is to know what new materials or circumstances there will be in 40 years time? The official estimate is that there is not enough sand and gravel for more than 20 years. If this is right, then an alternative will have to be found, and it may be decided that it will be better to exploit the alternative than to do so much damage."

Mr. Frank's remarks proved to be the more prescient. How fortunate for Devon that the Inspector and Minister both decided that the applications to extend Blackhill, and open new sites at Colaton Raleigh and Straitgate "be not approved."

What are we to learn from this? Some may conclude that mineral companies and Planning Authorities are poor forecasters of future aggregate demand. Others, that long term forecasting is fraught with difficulty and that the Council must take the utmost care in allocating sites, preferred or with permission, before they are truly required, and before all the alternatives have been explored. At the end of 2010 the County had 9.62 million tonnes of sand and gravel reserves, over 20 years worth with the ever decreasing amounts used each year. Borrowing the Inspector's concluding remarks, which still seem relevant today, there may be "408) (p)...other land with less disadvantages, and it is not possible to say now that the need for the Straitgate site is in any way overriding. For this reason any approval would be premature, and my recommendation not to allow that application also is on that basis, apart from water supply considerations."