Water Usage & Water Conservation Case Studies

Sappi Water Usage - Case Studies

Belgium: Lanaken Mill’s water usage

Lanaken Mill is located along the Albert Canal in Belgium. Since 1967, the mill has been licensed by the relevant national authority, nv De Scheepvaart, to source the required water from the canal for utilisation at the facility. The mill communicates regularly with the authorities and should any change to water usage be anticipated, permission is requested in advance. The mill actively manages groundwater utilisation, the shipping facilities along the canal and water discharge.

In 2018, Lanaken Mill used approximately 12.3 million m3 from the canal and 180,000 m3 of groundwater. In the same year, 12.5 million m3 of water was returned to the canal. The quality of water discharge is monitored daily by Sappi, periodically controlled by authorities on site or at various locations throughout the canal, and reported on annually as part of Sappi´s environmental reporting requirements. In addition, the mill continually implements projects to reduce water requirements or encourage water re-utilisation.

To prepare for increased production capacity through the ongoing rebuild project of PM8 at Lanaken Mill, in 2018 the anaerobic wastewater treatment plant was expanded and upgraded. This process is in the final stages with completion expected in December 2018.

The fact that Albert Canal becomes the source of drinking water for the city of Antwerp, 100 km downstream from the mill, highlights the mill’s high standards of water discharge quality.

Understanding the impact of water withdrawal on the river and estuary at Saiccor Mill

In terms of compliance to its water use licence, Saiccor Mill has commissioned an independent specialist to undertake annual estuarine health surveys of the Umkomaas estuary on which the mill is situated. In addition to these annual surveys, periodic low flow studies are also undertaken during drought periods when it is anticipated that the impact of freshwater removal from this system would be at its greatest.

These studies have been conducted by Marine and Estuarine Research (MER) since 1998 and various physico-chemical and biological indicators to assess estuarine health are used. These studies are submitted annually to the responsible authority and are also peer reviewed by an independent specialist. To date MER has issued 45 reports detailing the results of their studies of Saiccor Mill’s Estuary Monitoring Programme. In August 2018, MER summarised their findings, which revealed that whilst short to medium term changes do occur in response to low freshwater input during low flow periods, the estuary remains in a good ecological state.

Reducing water usage at Tugela Mill

High demand for a high-performance fluting grade, UltraFlute produced at Tugela Mill, increased the internal requirements for high quality neutral sulfite semi-chemical (NSCC) pulp from the semi-chemical cooking process. With the assistance of the Sappi Technology Centre, the mill embarked on multiple projects to improve the washing in the pulp plant and ensure quality pulp transfer to the paper machine.

The results led to modifications to the washing stages and filtrate system that was contrary to the original equipment manufacturer (OEM) design. However, the end result significantly improved pulp quality. Further improvements made in the pulp plant included the reuse of process water and the introduction of closed loop Seal water systems. These initiatives not only reduced water consumption, but also yielded some energy savings.

The cleaner pulp to the paper machine had a direct impact on the mill’s final effluent chemical oxygen demand (COD), reducing the COD load by 40%. The increase in direct pulp feed to the paper machine also reduced the water demand from the repulpers. Additional water reduction projects in the mill included the control of process water balances, fixing water leaks and passing valves together with inspections and repairs of open water storages, all of which resulted in further reduction in abstracted water of approximately 30%.

All the water improvements described above were made while the mill increased its pulp production by more than 23% and paper production by 5% over the same period.

Reducing water consumption at Gratkorn Mill

At the end of November 2017, we switched 105 m3/day of freshwater to use process water at one of our dust cyclones, resulting in water use savings of 38,000 m3 per annum. In addition, in April 2018, we began reusing process water in the thickener at the pulp mill. This resulted in process water savings of 15,000 m3.

At Sappi we regard water as a vital natural resource, therefore we try to use it as efficiently as possible in all our operations, read more here on Sappi's approach to water.