Definition

Water management encompasses the management of water flows and water quality, from abstraction from the natural environment to water flow restitution to the same or another environmental compartment.

Freshwater withdrawal (in millions of m³ per year) is the amount of incoming water from the public network (drinking water) and freshwater systems (rivers, lakes, etc.) as well as from groundwater sources (aquifers).

Chemical Oxygen Demand (COD) is the amount of oxygen reducing substances (mainly dissolved organic matter) discharged to aqueous receivers. COD is expressed as metric tons of oxygen per year. In addition to nitrogen and phosphorus species, Chemical Oxygen Demand also contributes to aquatic eutrophication.

Management approach

The Group has a company-wide water approach that includes a commitment to limit freshwater withdrawal and consumption, and to ensure that the quality status of the water bodies where effluents are discharged remains good, so that the impact on humans and natural biota is minimized. Solvay focuses on reducing two impacts: freshwater withdrawal and Chemical Oxygen Demand emissions.

Indicators and objectives

For 2019, the total water use of the Group is 1,350 Mm³, from which 1,236 Mm³ is used for cooling and 114 Mm³ for other process needs. Because around 70% of the cooling water is actually being recycled, the water we need to pump from natural resources is significantly less (426 Mm³). From this amount, 60% is coming from fresh surface water, 19% from ground water, 16% from sea water and the remainder from a variety of other sources. The total water discharged by the Group amounts to 387 Mm³, from which 253 Mm³ to freshwater receivers, 100 Mm³ to the sea and to third parties (34 Mm³), the remainder of the water being captured in products (13 Mm³), waste (0.5 Mm³) or lost by evaporation in cooling towers (20 Mm³).

The freshwater withdrawal intensity has been reduced by 48% since the start of the environmental plan, meaning that Solvay has already exceeded the 2020 target. Similarly, the Chemical Oxygen Demand emission intensity was cut by 49%, again far better than our initial commitment. It should be noted that the majority of these reductions are due to the divestment of the Performance Polyamides business.

Since the start of the ongoing environmental plan (2015-2020), the freshwater withdrawal from the plants has decreased by 39% (or about 10% per year). The 2019 freshwater withdrawal at Group level did not change versus last year, although changes could be observed for some of our GBUs: Aroma Performance (+0.82 Mm³), Soda Ash & Derivatives, + 1 Mm³), GBU Coatis (-1.4 Mm³), Novecare (-0.77 Mm³). These changes can be attributed to market evolutions.  

The Chemical Oxygen Demand releases from the Group were 904 tons or 14% lower than in 2018. This global change is due to significant decreases at the sites of Spartanburg in the United States (- 293 tons), Vernon in the United States (-314  tons) and Paulinia in Brazil (- 168 tons) whilst higher emissions were noted at Tavaux in France (+ 87 tons). For Spartanburg, Chemical Oxygen Demand emissions could be reduced thanks to an improved nutrient enrichment to the Waste Water Treatment Plant (WWTP). The decrease at Vernon is the consequence of lower production rates compared to 2018, which was an exceptional year. Regarding Paulina, the reduction can be attributed to an improved control and performance of their WWTP and more stable inflows from the adipic acid plant.

It should be noted that around 22% of the Chemical Oxygen Demand emissions declared by Solvay (thus roughly 1,200 tons) are due to third parties (typically companies which formerly belonged to Solvay, from which we are treating the effluents through service level agreements. This way of reporting is compliant with the requirements of the GRI-101 standard.

Since the start of the ongoing environmental plan (2015-2020), the Chemical Oxygen Demand emissions have decreased by 39% (or about 10% per year). The biggest part of this reduction is due to the divestment of the polyamides business.

COD improvements in 2019 were the consequence of a better control and performance on some of our major waste water treatment plants.