The main siliceous material production sites in France are located between the Seine-Maritime and the Gironde departments, in shallow areas of less than 50 metres.
Production of siliceous aggregates in metropolitan France (1000 tonnes)
Source : Union nationale des producteurs de granulats (UNPG)
The production of siliceous marine materials accounts for around 1.9% of the national production of construction materials, estimated at 447 million tonnes in 2007 (source UNPG). By comparison, this ratio was 20% in England/Wales in 2005 (source BMAPA).
French overseas departments also produce marine materials:
- 300 000 tonnes in Guadeloupe on a single site;
- very small rate of production in Saint-Martin;
- 20 000 tonnes in Saint-Pierre-et-Miquelon.
The production of limestone materials (shellfish sands and maerl), mainly in Finistère and Côtes d'Armor, is around 500 000 tons, in 2007/2008. The shutdown of maerl extraction was planned for 2013.
The overall turnover in 2007 was around 75 million euros (Ifremer estimate after consultation with professionals). This estimate was limited to extraction, landing, drying, calibration and loading for delivery (excluding processing). Under this assumption, the added value would be around 25 million euros (Ifremer estimate).
Employment and business
For their involvement in siliceous and calcareous marine materials, Unicem estimates 12 extraction companies for about fifteen sandships, 200 sailors and, 100 jobs ashore (administration and technical-commercial). Some of these companies upgrade material after processing, as part of their ready-to-use concrete or public works activities. The extraction of marine materials is also carried out by industrialists exploiting land-won deposits and eager to diversify their supplies. Extractions may be subcontracted to foreign shipowners.
Of this group of companies, 7 companies, registered in France, arm 9 ships assigned to sand mining; they employ around 50 sailors and personnel ashore.
The extraction of marine aggregates is an asset given the increasing difficulties of access to land-won deposits, particularly to alluvial aggregates. Currently, there is an increasing number of applications for extraction permits for the Channel region.