Proceedings

Abstract

The Water Framework Directive has resulted wide scale implementation of tighter phosphorous standards down to 0.5mg/l. To achieve this level of treatment requires average suspended solids of approximately 5mg/l on a consistent basis. A robust design as well as enhanced operational and capital maintenance regimes are required to meet this tightened discharge standards. The standard design strategy consisted of 2 point ferric dosing and tertiary treatment. The biggest risk to the projects were the use of existing assets and their condition. These projects also faced commissioning challenges and a number of key lessons were learnt. Short term operational experiences will also be discussed. As we look into AMP7, the Water Framework Directive will result in further tightening of Phosphorous consents to 0.25mg/l. Implications of these new consents and their impact based on initial lessons learnt will also be discussed.