Emissions of chemicals to water are dependent on the respective types and processes of chemical or pharmaceutical production at our manufacturing plants.
Lead parameters monitored for water pollution are organic load as total organic carbon (TOC) or chemical oxygen demand (COD), heavy metals, nitrogen and phosphorus. Depending on the site-specific processes and production, local requirements may include also other relevant parameters, which are not consolidated on Group level.
Organic substances in effluent waters are measured as total organic carbon (TOC) in metric tons C, or chemical oxygen demand (COD) in metric tons O2. Heavy metals are presented as metric tons of the sum of Arsenic( As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb), Mercury (Hg), Nickel (Ni) and Zinc (Zn). The main source of heavy metals, predominantly Zinc and Nickel, is the usage of metal containing catalysts. The eutrophying nitrogen (N) and phosphorous (P) containing compounds are measured in metric tons of N and metric tons of P, respectively.
Emission values presented in this section relate to after final water treatment and thus before entering receiving waters. Where sites do not operate their own final treatment, the data are determined together with the external treatment plant's elimination performance. The absolute load is obviously dependent on company size, production volume and production portfolio of our industrial processes, and will thus vary over time.
TOC & COD
Total organic carbon (TOC) is a measure of the organic load to effluent waters. It is composed of dissolved organic carbon and non-dissolved organic carbon. Chemical oxygen demand (COD) is another widely used measure for the degree of water load with organic pollutants. Absolute values of TOC and COD outfall to receiving waters are presented in the following chart, indicating process changes as well as the larger industrial activities after the Arch acquisition.
Heavy metals outflow is essentially the result of variations in the product mix and the usage of the catalysts involved. The chart shows the absolute values of the heavy metals load after final treatment, and hence is also dependent on production volume and company size.
Heavy metals load to receiving waters in 2016 amounted to nearly 1 metric ton, 17% upon the previous year. Again, the most abundant species in the reporting year was zinc with a share of 52%; the least abundant was mercury with 0.32%. Zinc, nickel and copper together accounted for 89% total heavy metals load to water.
Heavy metals in this context represent the sum of Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Mercury (Hg), Nickel (Ni), Lead (Pb), Zinc (Zn).
Nitrogen & Phosphor
Lonza's nitrogen load (mainly in the form of ammonia) does not exhibit clear trends and is controlled by product portfolio and volumes while technical measures follow state of the art water treatment technology and associated regulatory permitting. The last 7-year period shows peak years between 2012-2014 and a variation between 500 and 700 metric tons of nitrogen. For 2016 we report 600 metric tons, 16% up on the previous year. Visp (CH) as the largest and most complex multi-plant site accounts for 90% of the total nitrogen load of Lonza in 2016. All emissions are kept below the permitted levels and Lonza's efforts to keep nitrogen emissions low are continuing.
Phosphor emission to water, mainly in the form of phosphate, is monitored regularly as well. For the period under consideration it varies between 24 metric tons (2010) and 59 metric tons (2012). The year on year variations with a median load of 31 t are essentially controlled by the pharma activities and their portfolio (buffer media contribution). Total phosphor load in 2016 was 31 metric tons. At this level we do not consider the global phosphor emissions of the Group a significant contribution to waterways.