WATER SUPPLY

Drinking water Process water Fully desalinated water Circulation water Water distribution

A company of and LANXESS HISTORY OF WATER SUPPLY

1893 First water supply in Leverkusen 1909 Start of production of desalinated water in Leverkusen 1912 First process water supply at Uerdingen site and also construction of first cooling tower to conserve cooling water 1917 Construction of the first drinking water supply and a softening plant in Dormagen 1925 Construction of the first river water plant in Uerdingen 1925 Start of centralized, combined heat and power generation in Leverkusen 1934 Separation of process and drinking water at the Leverkusen site 1939 Construction of the first desalination plant at the Uerdingen site 1950 Completion of the river water plant in Leverkusen begun during the war 1957 Construction of the Hitdorf water plant and the long-distance pipeline to Leverkusen 1958 Maximum process water production of 10,000 m³/h achieved in Uerdingen 1960 Construction of the Monheim water plant and connection to the Leverkusen water network through a long-distance pipeline to Hitdorf 1961 Construction of the first cooling tower in Dormagen 1962 Production of 400 m³ of fully desalinated water per hour in Leverkusen 1969 Reconstruction of the Leverkusen river water plant 1973 Introduction of the fluidized bed process in fully desalinated water production for reducing consumption of hydrochloric acid and sodium hydroxide 1975 Construction of a partial stream filter in Uerdingen to reduce the contaminant content in circulation water 1983 Use of waste heat in the Uerdingen fully desalinated water plant for more efficient degassing 1987 Conversion of a Dormagen fully desalinated water plant to the fluidized bed process 1994 Modernization of the Hitdorf drinking water plant 1997 Reconstruction of the central control center in Leverkusen 2002 Commissioning of the first GRP cooling tower in Uerdingen 2005 Commissioning of the pilot plant for treating additional cooling tower water by membrane technology in Uerdingen 2006 Construction of the Monheim – Dormagen culvert for supplying process water 2008 Reorganization and streamlining of the water supply 2011 Renovation of the control system for the Uerdingen river water plant 2013 Construction of a new cooling tower in Dormagen 2014 Completion of the renewal of the complete control system in Leverkusen

1 WATER SUPPLY – Introduction INTRODUCTION

CURRENTA consumes approximately 400 million cubic meters of water every year for cooling, generating steam and rinsing, and for use as a solvent and drinking water.

An overview of our water:

Drinking water Process water Circulation water Water just like what comes out of the Clean water that is not monitored in Conditioned process water that is faucet in private households. Quality line with the German Drinking Water cooled in cooling towers and used in line with the German Drinking Ordinance, for cooling, cleaning, etc. multiple times. Water Ordinance.

Surface water Bank infiltrate Groundwater

Fully desalinated Drinking water Process water Circulation water water Boiler water

Fully desalinated water Boiler water High-purity water, basis for steam Similar to fully desalinated water, generation and raw material for but conditioned and pre-heated. production. WATER SUPPLY – Introduction

Water is our most valuable foodstuff. It is essential for agricultural operations and thus also for the production of the majority of foodstuffs. We use water every day for personal care, for hygiene and in our households. And last but not least, clean water is also crucial for most industrial processes. It is therefore understandable that the first reason for passing the European Water Framework Directive (EU-WFD) reads: “Water must be managed and protected. It is not merely a consumer product, but a precious natural resource, vital to future generations as well as our own.”

Despite its vital importance, we take it for granted that the required amount of clean water will come out of the faucet as soon as we turn it on. To ensure that this is the case at CHEMPARK and the surrounding communities, CURRENTA’s water supply staff are faced with a large number of technical challenges each and every day. And since the natural water supply – be it surface water or groundwater – is constantly replenishing itself, but not to the extent that we would like, we conserve this valuable resource. The water that we treat is a balanced mixture of surface water (from the Rhine, to be precise), bank infiltrate (also from the Rhine) and a small amount of groundwater. This variable water sourcing also ensures exceptional security of supply.

As a competence center for pure water for the chemical industry, CURRENTA Water Supply reliably provides the three CHEMPARK sites in Leverkusen, Dormagen and -Uerdingen with the volume of water they require, in whatever quality they desire – a total of 400 million cubic meters per year, which is more than the capacity of the Tegernsee lake. Quality ranges from process water to drinking water that complies with the German Drinking Water Ordinance and high-purity fully desalinated water. Through our own long-term water rights, reliable production facilities and highly qualified staff, we safeguard security of supply for our customers at CHEMPARK and also in the neighboring communities. The Water Supply segment provides more than just water, however. It also provides support in all issues relating to water legislation, keeps you informed of current issues and represents you in dealings with the authorities and institutions.

02 03 WATER SUPPLY – Prudent water management PRUDENT WATER MANAGEMENT

When it comes to extracting, using and treating water, CURRENTA Water Supply undertakes wide-ranging activities to protect waterways and the environment.

Protecting waterways together

To ensure it remains possible to supply clean water in the Precise knowledge of these correlations are necessary long term using treatment methods that are in harmony before a well can be drilled, for example. At the same with nature, CURRENTA Water Supply has joined forces with time, we are in close contact with the relevant authorities, trade associations (for example the IAWR – International because the legal situation governing water always Association of Waterworks in the Rhine Catchment Area) to demands collaboration with the local authorities protect waterways, because “Protecting the water situation responsible. Monitoring groundwater flows is also [...] will have economic benefits [...]” (EU-WFD). mandatory.

CURRENTA also maintains its own partnerships with agricultural firms to prevent any impairment of water quality before it occurs. Thanks to a closely linked groundwater measuring network and using hydrogeological models, we monitor groundwater flows around CHEMPARK and safeguard a reliable water supply while also protecting the groundwater. CURRENTA water managers also investigate the conditions in the ground and create detailed maps showing the interaction and behavior of groundwater flows in relation to the level of the Rhine and layers of soil.

Monitoring inside the cooling tower

04 Avoiding environmental impact Using energy efficiently

When taking water from wells, we are generally extracting We and our staff systematically use every opportunity Rhine bank infiltrate that quickly replenishes itself. This to save energy. In the last few years, Water Supply has comes from the river through the sand and gravel near the achieved an annual increase in efficiency of approximately bank. Adsorption and biological decomposition processes one to two percent. Employees make their own mean that it is naturally cleansed of many unwanted suggestions for improvements, which is a great help to us ingredients. In this way, we are also able to conserve in continuously improving our technology and reducing groundwater resources. energy consumption. Our industrial cooling systems apply the compression principle and operate many times We monitor the water quality of the Rhine. After all, this more efficiently than refrigerators or air-conditioning has a direct impact on the quality of drinking and process systems. While a typical household refrigerator generates water at CHEMPARK and the treatment it requires. The four kilowatts of cooling capacity from one kilowatt hour used and cleaned cooling and process water that we feed of energy, our plants achieve a cooling capacity of 150 back into the Rhine is noticeably different to river water. kilowatts from the same energy. It is considerably clearer. However, it is also somewhat warmer. To minimize the warming of the Rhine, we also use closed circuits with cooling towers. We replace the water lost through evaporation. However, since this is only a negligible amount, this also enables us to reduce the amount of fresh water we extract.

05 WATER SUPPLY – Water extraction plants WATER EXTRACTION PLANTS

CURRENTA Water Supply extracts cooling and process water primarily from river water plants on the Rhine, while wells form the basis for the production of drinking and fully desalinated water.

06 Since we have such a wide range of very variable “sources” for our water, we have to transport it to the treatment plants using different extraction units. We extract surface water from the Rhine using intake structures, while bank Humus infiltrate and groundwater are taken from wells. We use both horizontal and vertical filter wells. Meadow loam At-rest water level

Operating water level

Collection shaft Intake structures in the river water plant Quaternary (sandy rough gravel, aquifer) Surface water is taken from the Rhine using intake structures. Depending on the composition of the riverbed, these can be constructed on the bed of the Rhine, at the edge of the riverbank or in a kind of quay wall. Intake Holding pipe structures in the riverbed have the advantage that they can still take in water even when the river level is low. However, Tertiary (fine sand) they also take in a large amount of bed load with the river water, which means they are generally not in operation when the river level is medium or high. Intake structures on the bank, on the other hand, require a minimum water level and have to be closed off at breaker level if there are any floating pollutants (oil films on the river water, for example).

Horizontal filter wells

Horizontal filter wells make use of the approximately 20-meter-thick gravel and sand in the low terrace and lower mid-terrace of the Rhine. The shaft diameter is Schematic of a horizontal filter well generally around five meters. At a depth of just under 20 meters, 30- to 60-meter-long filter sections extend outward in a star formation. Some of the wells have Humus been in operation for over 50 years. Some are located Outer observation pipe in the Rhine’s natural flood plain and still contribute to Inner observation pipe CHEMPARK’s supply even when the river is in spate. Meadow loam Siphon system Vertical filter wells Sand Counter filter Wells of this kind are far smaller than horizontal filter wells. The filter pipes through which the groundwater flows into the vertical filter wells stand vertically and are part of the Extension pipes DN 400 significantly narrower well shaft. Often, an unassuming Quaternary access cover is the only manifestation of this kind of well (sandy rough gravel, aquifer) above ground.

Stoneware rib filter DN 400

Filter gravel Intake manifold DN 200 Sump pipe DN 400 Tertiary (fine sand) Borehole diameter 1.00 m

Schematic of a vertical filter well

07 WATER SUPPLY – Treatment processes TREATMENT PROCESSES

Process water, cooling water, fully desalinated water and drinking water – CURRENTA Water Supply employs a wide variety of treatment processes.

08 Well Raw water intake

Gravel/ River Passage of the river water sand fill through the ground

Clean water outlet

Structure of a filtration plant Schematic of bank filtration process

To produce process water, cooling water, fully desalinated Filtration and degassed water and drinking water, we employ a balanced mixture of tried-and-tested and future-focused During filtration, water is passed from top to bottom technologies. We also regularly look into the use of through gravel or sand filters (depending on the purity alternative treatment processes. Depending on the quality required). While the water is flowing through the cavities of the raw water and the type of water produced, we in the gravel fill, the dirt particles come into contact with employ different processes that our plants combine in the grains of the filter material, where they are deposited different ways. and thus removed. Having been freed of pollutants in this way, the clear water leaving the filter is already of sufficient quality for process water. Coarse cleaning

Coarse cleaning is primarily employed as the first Bank filtration treatment step for surface water (i.e. Rhine water) that CURRENTA only uses for process water production. This Bank filtration involves taking water from a waterway – removes coarse pollutants from the raw water (such as in our case the Rhine – by drilling wells close to the river pieces of wood or plastic). To this end, we pass the water bank. Due to the proximity of river and well, such wells through rakes and screens. There are usually several of provide virtually pure river water and only very limited these in succession with decreasing mesh sizes. amounts of groundwater. On its way from the Rhine to the shaft, the water passes through the layers of soil of the bank, which act as a large gravel filter. Alongside the mechanical removal of suspended particles, biological decomposition processes also take place here that further improve the purity of the water. The bank infiltrate can therefore be used as process water without any further treatment. To achieve drinking water quality, further treatment steps are required.

09 WATER SUPPLY – Treatment processes

Aerating and deacidifying Ion exchange

To remove carbon dioxide from the water and at the same In the first desalination step, we remove the positively time enrich it with oxygen, we send it down a cascade charged cations such as calcium, magnesium and sodium. of pipe grids. It flows down the cascade as a thin film of To this end, the water flows through a fine-grained resin fill. liquid, thus bringing it into close contact with air that is The ions bond with the artificial resin beads and displace fed through the plant in a counterflow from bottom to top. H+ ions (protons) from their surfaces, which pass into The large surface area of contact between water and air the water. In the downstream anion exchanger, the same ensures there is an effective exchange of carbon dioxide principle is used to remove negatively charged anions (from water to air) and oxygen (from air to water). (for example sulfate or chloride ions) from the water and replace them with OH ions from the surface of the resin. This is how salt ions are removed from the water. The Adsorption H+ and OH- ions released into the water by the resins in the two exchange stages react with each other and form

The water is freed of trace materials and organic H2O – water. compounds in adsorption filters. In a similar way to gravel filters, the water flows through a fill from top to bottom. In this case, the fill consists of activated carbon or special resins. The pollutants attach themselves to the surface of the filter material and remain there. We use this process to remove organic compounds, for example, that can affect the smell or taste of drinking water.

Moist waste air Water intake Air outlet Warm water intake

Trickling filters

Dry air intake

Air Cold water intake outlet Water outlet

Schematic of a cooling tower Material transfer using a pipe grid cascade

10 Degassing Cooling

As well as the salt ions, we also have to remove the gases Circulation water used for cooling purposes in customer that are dissolved in the water so that it can be used plants is cooled in central cooling towers. In these towers, for generating steam. These gases are primarily carbon the water is atomized into fine droplets, trickles through dioxide and oxygen. As described in the “Deacidifying” filters on the inside of the tower and is collected in the cold section above, carbon dioxide can be removed using water basin. At the bottom of the cooling tower, ambient trickling filters. To remove the dissolved oxygen, we first air comes in from the side and comes into contact with the add hydrogen to the water in Leverkusen and Krefeld- water in a counterflow. A small amount of the circulation Uerdingen. It is then fed through a contact container filled water evaporates in the process. The evaporative heat loss with a catalyst in which the two dissolved gases react with ensures the remaining water is cooled efficiently. The now each other to form water. In addition, or alternatively (as moist air is then extracted through the top of the cooling in Dormagen), we can remove dissolved gases using a tower by a fan. Evaporation alone can cool the water to vacuum. This involves sucking them out of the water, so to as much as 15 °C below the ambient (air) temperature speak. (depending on the relative humidity). We replace the water lost through evaporation. Stabilization Pre-heating Depending on the purpose of the water, we also add various substances that prevent the growth of bacteria, In some cases, the fully desalinated water that we supply corrosion or barnacle growth. We use hydrogen peroxide for steam production in plants is already pre-heated. This or chlorine to prevent biological growth and protect the enables us to simultaneously use the existing waste heat, equipment in the water cycle, such as pipelines and heat which avoids the outlay involved in releasing it into the exchangers, from loss of efficiency and blockages. Sodium surroundings and increases the efficiency level of the hydroxide solution or ammonia, for example, are used as plants supplied. corrosion inhibitors in water destined for steam generation in power stations.

Process water water Circulation Circulation Fully desali- nated water water nated Boiler water Process water water Process Drinking water

Air Coarse cleaning outlet An overview of the processes and their areas of application Bank filtration

CURRENTA Water Supply boasts comprehensive know-how Gravel filtration and many years of experience in applying the processes described above, as well as detailed knowledge of their Aerating, strengths and weaknesses. Combined with CURRENTA’s deacidifying skills in the field of automation, this enables us to select Adsorption the best combination of processes available to match the relevant boundary conditions, which ensures a highly Ion exchange efficient water supply.

Degassing

Water outlet Stabilization

Cooling

Pre-heating

11 WATER SUPPLY – Plant types

River water plant

Inlet structure Pumping station Gravel filtration

Raw water

Rhine

Pit Feed pumps Rinse water

H O /Ag Process 2 2 water network Process water

Backwash water Sedimentation basin Inland waterway Direct transfer

Sediments

Circulation water cooling

Partial flow filter T 1

Analytical cooling water monitoring P

Settling basin Water added

Sewer Air Air

Heat exchanger P 1 T 1 Biocide Inhibitor

Dispensing and monitoring

Purging Overflow

12 WATER SUPPLY – Plant types

Drinking water treatment

Activated carbon double-layered filter

Deacidifying

Network pumps Preventive chlorination

Drinking water protection zone

Network Rhine

Raw water pumping Deacidifying / aerating Filtration and adsorption of organic water ingredients Disinfection

Full desalination plant

Regeneration Regeneration Conductivity Regeneration 6% HCl 3% NaOH < 20 µS/cm 3% NaOH H CO 2 + 2 - H OH

Storage

Cationic Trickling Anionic Catalytic Mixed bed - + exchanger filter SiO3 exchanger O2 reduction Na - ++ CO3 Mg - ++ Cl Ca - - SO4 Plants

Air Power plant

Fully desalinated Y water Conductivity < 0.2 µS/cm Process water Regeneration Conductivity 6% HCl approx. 700 µS/cm

Slightly Slightly acidic cationic Neutral acidic cationic exchanger filter exchanger Na+ form H+ form

Sewer

13 Published by Currenta GmbH & Co. OHG 51368 Leverkusen www.currenta.com

Last revised: May 2014