Water & Wastewater Treatment

WWT May 2019

Water & Wastewater Treatment Magazine

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Page 24 of 43

Databank www.wwtonline.co.uk | WWT | MAY 2019 | 25 GOAL 14 WASTEWATER QUALITY Environmental water quality in rivers and lakes istested by the Environment Agency and measured against standards set by the EU Water Frame- work Directive. The criteria tested include both chemical factors (i.e. the amounts of various substances in the water) and biological (the amount of animal and plant life present). Water bodies are given an overall rating of poor, moderate, good or high. Since a change to the assessment methods was made in 2014, in order to achieve 'good' status the water body must pass against all of the criteria, with a single failure being enough to ensure it misses out. Only 14% of rivers, and slightly more lakes and other water bodies, achieved good or better status when the last full year's statistics (for 2016) were published. Improvements set out in the various River Basin Management Plans (RBMPs) agreed for the 2015-21 period are intended to raise this ' gure to 21% by 2021. In most cases water com- pany activity is not the only or decisive factor in environ- mental water quality, but it is o" en a signi' cant contributor. Around 55% of UK rivers failed to meet good WFD standards on phosphorus, with waste- water treatment plants being an important source of this pollutant. In 35% of rivers that fail to achieve 'good' status, pollution from wastewater is thought to be a direct cause. While water companies are able to respond to many of these failures through actions agreed in RBMPs, it is o" en seen as uneconomic to achieve very low levels of phosphorus, especially when a water body is some way o– achieving good status and is also impacted by other pollut- ants or factors. ENVIRONMENTAL WATER QUALITY Issues preventing good ecological status of UK rivers (source: RBMPs 2015) (source: Environment Agency report Feb 2018) (Source: EA. Assessment method changed in 2014) (source: Water UK long term planning framework/Discover Water) 14% The proportion of rivers in England & Wales that meet good or better ecological status 16% The proportion of lakes in England & Wales that meet good or better ecological status 20% The proportion of estuaries in England & Wales that meet good or better ecological status Waterbodies and ecological status European comparison River has been physically modifi ed 39% River polluted by wastewater 35% River polluted from agricultural activity 35% River polluted from towns, cities and transport 11% Reduced river fl ow as a result of human activity 6% Pollution from abandoned mines 3% Negative eff ect of non-native species 2% % of rivers achieving good or better ecological status 2009 22 22 23 22 23 17 17 15 14 22 23 21 2011 2010 2012 2013 2014 2015 2016 Old method New method

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