A treatment plant is judged by one question: does its effluent meet the discharge limits consistently? That is why you need to clarify which regulations apply before design begins.
Two key regulations
In Türkiye, wastewater discharge is mainly governed by two regulations. The Urban Wastewater Treatment Regulation applies to municipal and domestic wastewater plants. The Water Pollution Control Regulation (SKKY) sets industrial discharge limits in tables organised by sector.
Typical limits for urban wastewater
- BOD5: 25 mg/L
- COD: 125 mg/L
- Suspended solids: 35 mg/L
- Additional total nitrogen and total phosphorus limits in sensitive areas
In lakes, reservoirs and coastal zones declared sensitive areas, nitrogen and phosphorus removal becomes mandatory. This means the process must move from conventional activated sludge to a system with nitrification-denitrification and biological/chemical phosphorus removal.
Industrial discharges
Industrial plants discharging to sewers must meet the local water utility’s sewer discharge limits; those discharging directly to a receiving body must meet the sector table in SKKY. In industrial zones, the zone management’s pre-treatment requirements also apply.
Impact on design
- Limits directly determine process selection and investment cost.
- No industrial plant should be designed without at least several days of composite sampling and analysis.
- Expandable designs are wise in case limits tighten in the future (e.g. sensitive area designation).
Let’s clarify the limits for your project together: just mention your discharge point in our contact form. Note: this article is for general information; always refer to the latest version of the regulation and the competent authority.