Amlaird WTW Catchment Risk Assessment.pdf

- Raw Water Quality:
- Generally good, but high and variable water colour (true colour up to 400 Hazens) is a consistent issue.
- Cryptosporidium breach occurred in 2006.
- Works originally designed for a maximum true colour of 244 Hazens.

- Catchment Geology & Land Use:
- Dominated by volcanic igneous rocks (basalt), less permeable, and combined with high rainfall, results in waterlogged soils and blanket peat cover.
- Main land uses: agriculture (rough moorland grazing and improved grassland), forestry (Whitelee Forest), and Whitelee Windfarm (28 turbines within the catchment).

- Agricultural Activities:
- Lochgoin Farm: 500 ewes, lambing in April/May, nitrogen, phosphate, and potassium (20:10:10) fertiliser applied at 190 kg ha-1 in spring.
- Myres Hill: 30 ewes (increasing to 300 in 2010/11).

- Risks to Raw Water Quality:
- Moderate to high Cryptosporidium risk due to livestock numbers.
- Other risks: diesel use (vehicles and wind turbines), chemical use/storage (windfarm), organo-phosphate sheep dip, diesel storage, inorganic fertiliser storage/application, septic tanks.

- Conclusions:
- Main risk to water quality is from livestock, leading to a moderate to high Cryptosporidium risk.
- Other potential risks include chemical and fuel storage, and agricultural activities.