PBU Norma K Malpils Wastewater Treatment Plant, Mālpils pagasts, Latvia

PBU Norma K Malpils is a municipal wastewater treatment facility located in Mālpils pagasts, Siguldas novads, Latvia. The plant serves a population of 655 and has a designed capacity of 7,000 m³ per day, with a current discharge volume of 182.83 m³/day. It provides secondary treatment, which is the standard biological treatment stage required for organic matter removal. As a plant in Latvia, PBU Norma K Malpils operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for agglomerations with a population equivalent (PE) between 2,000 and 10,000. Although the plant serves fewer than 2,000 people, it still meets the secondary treatment standard, reflecting Latvia's commitment to EU environmental regulations. The treated effluent is discharged into the local watershed, which ultimately drains into the Gulf of Riga via the Gauja River basin. The Gauja River is the longest river in Latvia and supports diverse aquatic ecosystems, including salmonid populations. Proper treatment helps protect downstream water quality in the Baltic Sea region.

The plant discharges into the Gauja River basin, which flows into the Gulf of Riga, part of the Baltic Sea. The Gauja River is an ecologically sensitive waterway supporting salmon and trout populations, as well as diverse riparian habitats. Effective secondary treatment reduces organic pollutants and nutrients, helping to prevent eutrophication in the Baltic Sea, a region already stressed by nutrient loading.