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Treharris, United Kingdom

Edwards P.J.,Dwr Cymru Welsh Water | Bochereau N.,EC Harris
IET Conference Publications

In 2008, Dwr Cymru Welsh Water (DCWW) recognised that PAS 55 certification would not only bring key benefits to AMP5's "business as usual" activities and beyond, but would also support the PR09 process. Achieving PAS 55 certification in March 2009, DCWW has been operating under the new accredited framework for almost 3 years. As part of the "Plan, Do, Check and Act" cycle, in January 2011 DCWW decided to undertake an assessment of how lessons learnt from the implementation of PAS 55 could drive further efficiencies. EC Harris was appointed to undertake a pilot study for the water treatment works programme and they identified around 10% of additional savings to be realised. This joint paper provides a detailed case study demonstrating how PAS 55 principles can deliver tangible improvements for an asset intensive utility company. Source

Bowles F.J.,Wessex Water | Henderson P.,Dwr Cymru Welsh Water
Fisheries Management and Ecology

The potential effects of abstraction for water supply on salmonid populations in England and Wales are reviewed. The duties of water resource planning and the contribution of the water industry investment in river basin management planning are discussed. Given the possible effects of climate change on public water supply and demand, and the uncertainty of hydroecological relationships, key principles to ensure long-term investment by water utility companies to meet European Union Water Framework Directive standards achieve the best benefit for salmonids are recommended. © 2011 Blackwell Publishing Ltd. Source

Gough R.,Bangor University | Holliman P.J.,Bangor University | Willis N.,Dwr Cymru Welsh Water | Jones T.G.,Bangor University | Freeman C.,Bangor University
Lake and Reservoir Management

Gough R, Holliman PJ, Willis N, Jones TG, Freeman C. 2012. Influence of habitat on the quantity and composition of leachable carbon in the O2 horizon: Potential implications for potable water treatment. Lake Reserv Manage. 28:282-292. Organic material leached from the organic (O) horizon of soils is a major source of natural organic matter (NOM) in surface waters. Dissolved organic carbon (DOC) is a known precursor for the formation of disinfection by-products (DBPs), including trihalomethanes (THMs), formed during chlorination. In this study the concentration and composition of leachable O2 horizon DOC from 5 habitats within a United Kingdom upland reservoir catchment (beech, spruce, larch, and pine forests and blanket peat) were compared with an emphasis on potential treatment implications using XAD fractionation and THM formation potential (THMFP) tests. Statistically significant differences were found between habitats, with pine and larch leachates yielding particularly high DOC concentrations (mean 19.3 and 13.4 mg/L, respectively) and THMFP 7d values (mean 1306 and 1527 μg/L, respectively). The interspecies variation observed suggests that the typical distinction made between deciduous and coniferous species in previous studies is overly simplistic. Interestingly, peat leachate exhibited a surprisingly low DOC concentration (mean 9.0 mg/L), suggesting that the high DOC flux associated with these habitats may be the result of other factors such as depth of organicmatter and mineral content. Averaged across all habitats, mean standardized THMFP (STHMFP) was highest in the hydrophobic acid (HPOA) fraction, although substantial differences in the relative reactivities of fractions were found between habitats. Synergistic effects are also likely to complicate the relationship between fractional character and STHMFP. © Copyright by the North American Lake Management Society 2012. Source

Kumi P.J.,University of South Wales | Henley A.,University of South Wales | Shana A.,Thames Water Utilities | Wilson V.,Dwr Cymru Welsh Water | Esteves S.R.,University of South Wales
Water Research

The extracellular polymeric substances and microbial cytoplasmic contents seem to hold inorganic ions and organic products, such as proteins and carbohydrates that are of critical importance for the metabolism of hydrolytic and acidogenic anaerobic microorganisms. The addition of soluble microbially recovered nutrients from thermally treated digestate sludge, for the fermentation of thermally hydrolysed waste activated sludge, resulted in higher volatile fatty acids yields (VFAs). The yield of VFAs obtained from the recovered microbial nutrients was 27% higher than the no micronutrients control, and comparable to the yield obtained using a micronutrients commercial recipe. In addition, the use of a low pH resulting from a high sucrose dose to select spore forming acidogenic bacteria was effective for VFA production, and yielded 20% higher VFAs than without the pH shock and this associated with the addition of recovered microbial nutrients would overcome the need to thermally pre-treat the inoculum. © 2016 Elsevier Ltd. Source

Macklin M.G.,Aberystwyth University | Tooth S.,Aberystwyth University | Brewer P.A.,Aberystwyth University | Noble P.L.,Dwr Cymru Welsh Water | Duller G.A.T.,Aberystwyth University
Global and Planetary Change

Many Mediterranean steepland rivers are flanked by extensive alluvial and colluvial deposits, but Late Quaternary histories of channel and hillslope behaviour remain poorly constrained, primarily because of the limited availability of material suitable for dating. Study of a 4.8 km long reach of the Anapodaris Gorge, located in the lower part of an ∼ 500 km 2 catchment in south central Crete, reveals a succession of well preserved, coarse-grained (predominantly cobble to boulder) and fine-grained (predominantly silt to sand) alluvial deposits that locally interfinger with, or are overlain by, coarse colluvial and tributary stream deposits. Detailed ground surveys, geomorphological mapping, sedimentological investigations, and geochronology (optically stimulated luminescence, radiocarbon, and lichenometry) have allowed detailed reconstruction of the timing and pattern of sedimentation and erosion over the mid to late Holocene. Widespread, coarse-grained aggradational episodes at c. 4.86-4.20 and c. 3.40-3.00 ka have been punctuated by incisional episodes and coarse sediment export, resulting in a suite of alluvial terraces. Comparison with other proxy Mediterranean environmental change records, particularly high-resolution marine and lake records, suggests that these aggradational/incisional episodes were primarily climatically driven, reflecting changes in the balance between hillslope/tributary sediment supply and high-energy flood events. By contrast, phases of widespread fine-grained aggradation at c. 1.90 ka, 1.13 to 1.10 ka, 0.85 to 0.70 ka and 0.21 ka provide evidence for decreases in flood competence, possibly coupled with up-catchment historical land use changes. Since the middle of the nineteenth century, several large floods have formed localised boulder berms and splays and have contributed to stripping of the fine-grained deposits from many parts of the gorge. The findings from the Anapodaris Gorge demonstrate the sensitivity of Mediterranean steepland catchments to rapid and/or short-lived Holocene climate change but also highlight the need for higher resolution data on historical and prehistoric land use changes. © 2009 Elsevier B.V. All rights reserved. Source

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