Muir of Ord New STW - Secondary Wastewater Treatment in Highland, Scotland

Muir of Ord New STW is a municipal wastewater treatment facility located in Muir of Ord, Highland, Scotland. The plant serves a population of around 4,343 and operates with secondary treatment, which is the standard for inland and coastal communities under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant has a designed capacity of 5,493 m³/day and currently discharges an average of 966.90 m³/day of treated wastewater. As a secondary treatment plant, Muir of Ord New STW provides biological treatment to reduce organic matter and suspended solids. The facility is situated near the coast, and its discharge is subject to regulatory oversight under Scottish environmental law, which implements the EU directive. For agglomerations of this size (under 10,000 population equivalent), secondary treatment is typically sufficient unless the receiving water is designated as a sensitive area. The treated effluent from Muir of Ord New STW ultimately enters the Cromarty Firth, a coastal inlet of the Moray Firth in the North Sea. The Cromarty Firth is an ecologically important estuary that supports diverse marine life, including seals, dolphins, and migratory birds. The plant's discharge must meet strict quality standards to protect this sensitive coastal environment.

Muir of Ord New STW discharges treated wastewater into the Cromarty Firth, a coastal inlet that connects to the Moray Firth and the North Sea. The Cromarty Firth is a designated Special Protection Area for birds and supports a rich ecosystem of marine species, including Atlantic salmon and harbor seals. The plant's secondary treatment helps reduce nutrient and pollutant loads, safeguarding water quality in this ecologically sensitive estuary.