Wastewater treatment in production
Level: Advanced
The largest environmental impact from textiles comes from production. Requirements on wastewater treatment reduce emissions from textile production.
Details
- Type:
- Technical specification
- ID:
- 11457
- Group:
- All textiles
- Swedish:
Criterion text
For wastewater1 treated in the production plant, and discharged directly into the recipient, the following shall be met:
- The COD2 discharged shall not exceed 45g/kg textile for wool.
- The COD2 discharged shall not exceed 20 g/kg textile for other textiles than wool.
- The pH shall be 6 - 9, unless the recipient’s natural pH deviates from this range
- The temperature shall not exceed 40 ºC unless the recipient naturally has a higher temperature.
The requirement covers at least the process steps of dyeing, and preparation in the production of the main component3 of the textile.
1Closed systems that do not generate wastewater are not included in the requirement.
2COD (Chemical Oxygen Demand) can be measured according to ISO 6060 or a similar method. It can also be measured as TOC (Total Organic Carbon), pCOD (particulate Chemical Oxygen Demand) or BOD (Biochemical Oxygen Demand) if a correlation to COD can be displayed.
3The material constituting at least 70% of the respective textile product covered by the contract.
Verification
The supplier shall, upon request, be able to present any of for example the following:
- Valid license for any of for example the following labels:
- Nordic Swan Ecolabel of Textile, hides/skins and leather, version 5
- EU Ecolabel for textile products, 2014/350/EU
- GOTS, version 6.0 (2020) or version 7.0 (2023)
- Analyses reports showing measured COD-values, pH-values, and temperature for wastewater after treatment. The COD-emissions shall be calculated as an average for, for example 6 or 12 months of production. COD can be measured according to ISO 6060 or a similar method. It can also be measured as TOC (Total Organic Carbon), pCOD (particulate Chemical Oxygen Demand) or BOD (Biochemical Oxygen Demand) if a correlation to COD can be displayed.
- The supplier’s self-declaration including technical documentation of compliance verified by an accredited verification body, accredited for the task in accordance with ISO/IEC 17029 or equivalent standard.
Proposed follow-up
Labelling
If the requirement has been verified with a label, check that there is a valid license for the product in question. This can be checked on each website: Nordic Swan Ecolabel, EU Ecolabel, GOTS.
Analysis report
If the requirement has been verified with analysis reports, perform spot-checks on the analysis reports and check that the measured values for COD, pH and temperature are below the limit value of the requirement.
Self-declaration verified by an accredited verification body
If a verified self-declaration is used to prove that the requirement is fulfilled, request the supplier’s self-declaration, including documentation showing that the requirement is met. The self-declaration shall be verified by a verification body accredited for the task in accordance with ISO / IEC 17029 or equivalent standard.
Information about the criterion
The requirement only covers wastewater treatment in on-site plants that are present during production to purify wastewater that is discharged into the recipient. Off-plant treatment plants and closed processes are not covered by the requirement, as they do not discharge wastewater to the recipient.
The measurement method for COD includes mercury, which is environmentally hazardous. To avoid the use of mercury, measurement of pCOD, TOC or BOD can be used if a correlation to COD is displayed. The TOC value is about 30 percent of the COD value, but the percentage varies between different plants.
The requirement is used in combination with the core criterion CriterionID 11451.
There are currently a limited number of accredited verification bodies according to ISO / IEC 17029 (Conformity assessment - General principles and requirements for validation and verification bodies), as it is a relatively new standard. However, this may change, especially if the demand for verifying compliance in this way increases. This possibility is therefore included in the list of possible verifications. More information about the standard is available at www.swedac.se.
Versions history
The version date indicates when the sustainability criterion was created or last updated. Last reviewed dated tells when we last checked that the sustainability criterion still is relevant.
- Current ID
- 11457
- Version date
- 2021-05-25