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 2015 amounted to 0.8 metric tons, 27 % down on the previous year. Again, the most abundant species in the reporting year was zinc with a share of 43 %; the least abundant was mercury with 0.16 %. Zinc, nickel and copper together accounted for 81 % 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
Since 2009 we observed a rising trend of the nitrogen load (mainly in the form of ammonia). For 2015 we report 516 metric tons, 28 % down on the previous year. Visp (CH) as the facility with the far most nitrogen load accounts for 88 % of the Group, due to specifics of the production portfolio. In 2015, production at Visp could reduce the N-emissions by 29%. 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. For the period under consideration it varies between 3.2 metric tons (2009) and 60 metric tons (2012). the year on year variations with a median load of 28 t are essentially controlled by the pharma activities and their portfolio (buffer media contribution). Total phosphor load in 2015 was 23 metric tons. At this level we do not consider the global phosphor emissions of the Group a significant load.