Wastewater (water effluents)

[GRI 303-1, 303-2, 303-4; ESRS E2-2, E2-4, E2-5]

The management of water discharge-related impacts is reported in chapter “Water stewardship”.

Process water is treated by biological wastewater treatment plants (WWTPs). The Lenzing Group has wastewater treatment plants at all its sites except Grimsby (United Kingdom). However, the wastewater situation at Grimsby complies with all local laws and regulations as well as the EU Water Framework Directive. In order to meet even more ambitious Lenzing Environmental Group Standards, planning has begun for the construction of a wastewater treatment plant at the Grimsby site in cooperation with local government with a view to applying new technology from an ongoing R&D project.

Organic chemicals from waste streams from the pulp production process are extracted early on in the biorefinery process at the Lenzing (Austria), which significantly reduces the chemical oxygen demand (COD) of effluent water. This is one example of best practices where potential waste streams are converted into useful products, thereby avoiding pollution and reducing the amount of waste to be treated at the wastewater treatment plant.

Lenzing’s plant in Purwakarta (Indonesia) is making good progress in improving its wastewater after a project was launched in 2018. Waste collection and treatment systems are flagged to be upgraded to ensure that wastewater treatment performance is always able to meet local regulations and future requirements. The project also involves constructing a water treatment system and repairing an existing rainwater drainage system. The project is targeted for completion mid-2023. This is in line with Purwakarta’s (Indonesia) future project targets, which strongly support sustainable improvements that reflect best available technologies.

In 2021, another WWTP upgrade project was approved for the site of Mobile, USA. The lyocell plant was one of the first of its kind and will undergo a modernization of the existing WWTP in order to meet the Group’s sustainability strategy and target for COD emissions. This investment will not only help to fulfill future ZDHC requirements for lyocell production but will also allow potential enlargement of fiber production capacity. The project includes the refurbishment of existing structures and new modular elements for the most up-to-date waste water treatment. The investment thereby extends the life cycle of the WWTP. After the project was successfully approved, construction work was initiated in late 2021. Conceptual design and clearance work continued in 2022. The project is on schedule and expected to be commissioning by the end of 2023.

Sustainable pulp and fiber production comes with strict criteria not only for air emissions but also for water effluents and wastewater treatment. National or regional legislation as well as several industry standards and certification schemes – such as EU BAT, EU Ecolabel, and ZDHC – identify priority substances of concern and give guidance for reducing emissions and hence avoiding harmful impacts on water bodies. Lenzing has decades of experience in the safe handling and treatment of process chemicals used during manufacturing, including water-related issues. Lenzing has been leveraging this extensive knowledge to develop and shape today’s industry standards through multi-stakeholder initiatives such as ZDHC. Discharge limits are included in the environmental permits issued for all sites by relevant authorities based on national legislation. Additional intragroup discharge limits that reflect best practices may apply under internal environment standards.

The Group Environmental Standard is designed to reflect the benchmarks and emission thresholds of the best available technologies for industrial pulp and fiber production. The ambitious framework of the standard aims for continuous improvement. That said, some requirements have not been met by particular sites. However, no infringements of regulatory discharge limits occurred during the reporting year.

Sulfate emissions mainly originate from the viscose process; COD emissions originate from pulp and all fiber production processes. Their reduction is part of the Lenzing Group’s sustainability targets. Total emissions of COD and amines maintained same levels compared to last year, while sulfate emissions decreased due to lower viscose production. This is also true for specific sulfate emissions. On the contrary, higher but still slightly instable lyocell operations led to an increase of specific emissions of amines (see tables below).