Proceedings

Nutrient pollution

• Water quality is a key concern, and many water quality problems arise from multiple sources of pollution.

• To achieve the regulatory P reduction objectives, WwTW permit limits are becoming increasingly stringent.

• Tighter permits in smaller WwTWs can make P removal practically difficult as well as expensive.

• The challenge of meeting the P objectives in rural catchment often goes beyond water company activities.

Challenges and opportunities

• The River Petteril is a tributary of the River Eden, Cumbria, UK and the catchment is mainly agricultural.

• Local ecology is impacted from significant nutrient inputs – Phosphorus from wastewater discharges and agriculture.

• To achieve good ecological status, action was required to reduce phosphorus load entering the river.

• In AMP6 and AMP7, four of UU’s WwTWs in the Petteril catchment had WFD regulatory drivers.

• From baseline data it was clear that the WwTW alone would not resolve the problem.

• We used our innovative CaST Strategy and initiated a Catchment Nutrient Balancing (CNB) approach.