Water and Effluent Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/468709
M any have labelled the ongoing trend of ris- ing nitrate concentra- tions as the 'nitrate time bomb' as it is unclear when contamination levels may peak and how high they could get. However, a review of data for the 44 worst affected groundwater sources in the Midlands and North-west shows that this is not actually the case, with many of the concentration trends already levelled out or beginning to decline. The reduction and levelling out in nitrate contamination is in no small part a result of sta- bilisation in recommended fertiliser applications to ara- ble crops and the amount of fertiliser applied to pastures having halved since the 1980s. Code In 1989, about 1% of the popu- lation was receiving water that failed to comply with the directive (EC Directive on the Quality of Drinking Water) set in 1980. Subsequently, in 1991 the EC Nitrate Directive was agreed, which required all member states to control the levels of nitrate in drinking water. The government has spear- headed a number of schemes that have played a huge role in helping to reduce nitrate concentrations in groundwa- ter, as well as produce a Code of Good Agricultural Practice for the Protection of Water in order to meet these requirements. The schemes have included identifying Nitrate Vulnerable Zones (NVZ), Nitrate Sensitive Areas (NSA), and safeguards and environmental steward- ship schemes. NVZs are desig- nated where land drains and contributes to the nitrate found in contaminated water, with around 70% of the land in England recognised as this. Farmers operating within these areas are required to comply with a number of rules that ensure the safe use and storage of fertiliser and manure. Those who do not comply may face penalties. Farmers Those outside NVZs were encouraged to follow best practice, and the NSA scheme saw areas acknowledged where nitrate concentrations in drinking water sources exceeded or were at risk of exceeding the directive, and voluntary agricultural meas- ures were introduced by Defra that saw farmers offered pay- ments in return for complying A solution: Establishing NVZ and NSA schemes Find out what's fl owing where with the rugged new addition to the portable range of clamp-on fl ow meters from MICRONICS The Portafl ow range brings simplicity to the non-invasive measurement of liquid fl ow. PF440IP offers the user quick and accurate fl ow measurement with its easy to follow menu and simple set up. Results can be achieved within minutes of opening the case! Compact, rugged and reliable with an IP67 case and IP68 rated transducers, the PF440IP has been designed to provide sustained performance in hostile industrial environments including demanding external fl ow and submerged transducer applications for sustained periods of up to 4 months with 1 hour interval logging. ■ DSP measurement technique ■ Reynolds number correction ■ Easy to install ■ Simple to follow programming menu ■ Clamp-on IP68 rated sensors ■ Suitable for external applications www.micronicsfl owmeters.com or call 01628 810456 MADE IN BRITAIN 0776_Micronics PF440IP Half Page Ad 98x268mm v1.indd 1 22/05/2013 08:34 Collaboration with with the agricultural sector can help reduce nitrate levels further. Farmers operating within the NVZ and NSA areas are required to comply with a number of rules "...collaborative working may be the key to reducing surface run-off" Steve Buss with rules for use of fertiliser and manure. The scheme started as a pilot and was implemented across 32 areas, playing a key role in reducing nitrate concentra- tions and providing effective management for supporting farmers. The stabilisation and pos- sible slight declines in nitrate concentrations across some parts of the Midlands and the North in particular is posi- tive evidence for engaging farmers in discussions on how to reduce nitrate inputs (and impacts) further further – using the methods explored by the government (NSA and NVZ schemes) as a starting point. Engagement and collaborative working may be the key to reducing surface run-off and direct con- tamination of nitrate into the public water supply. Trends There still is a lot of nitrate in the system and there is still a lot being applied to farmland so any changes will be subtle. But if we can stabilise ris- ing trends, reverse stable trends and accelerate declin- ing trends, this may allow water companies to defer or avoid investment in new nitrate treatment plants, which can save water compa- nies' bill payers millions of pounds and reduce carbon emissions. n Steve Buss is catchment man- agement specialist with ESI.