- Email: [email protected]
Microbial and nutrient contaminants of fresh and coastal waters
ARTICLE IN PRESS
Journal of Environmental Management 87 (2008) 533–534 www.elsevier.com/locate/jenvman
Editorial
Microbial and nutrient contaminants of fresh and coastal waters Water quality protection is important from both human health and environmental perspectives. Drinking water quality is an issue of global human health concern, principally due to water contamination with pathogens and potentially toxic chemicals. Contaminants in freshwater resources can arise from a variety of sources including those associated with the treatment and disposal of sewage and agricultural livestock wastes. Pathogenic contaminants from these mixed sources include viruses and bacteria such as Escherichia coli O157I and the protozoa Giardia and Cryptospordium parvum raising issues in terms of drinking water (e.g., Directive 98/83/EC) and recreational use such as bathing waters (Bathing Water Directive, 76/160/EEC). For example, the town of Walkerton (Ontario, Canada) experienced the largest waterborne disease outbreak in Canada (Goss and Richards, 2008), which was linked to the contamination of the water supply system with pathogens that originated in manure, resulting in 2300 cases of gastroenteritis and seven deaths (cf. Goss and Richards, 2008). Similar outbreaks of cryptosporidiosis in England and Scotland were attributed to slurry spreading or other cattle activities (cf. Hooda et al. 2000a). The Bathing Water Directive sets a number of mandatory microbiological and chemical standards which bathing waters should comply with. Within rural settings the major diffuse and point sources of microbial contamination are largely associated with livestock farming activities; however waters in catchments with no livestock or other apparent sources can be contaminated by wildlife sources (Hooda et al., 2000a). The compliance with microbiological standards can also be compromised in catchments with no obvious direct point or diffused sources, as discussed by Stapleton et al. (2008) where untreated sewage overflows accounted for 490% of the total microbial load. Clearly compliance with the Bathing Water Directive as well as for public health protection all potential sources need to be regularly assessed/ monitored in order to develop effective water quality management strategies. Nutrient enrichment, mainly with phosphorus (P) of freshwaters can cause excessive growth of algae, leading to general degradation of aquatic ecosystems, including loss of biodiversity. The role of nitrogen (N) in eutrophication 0301-4797/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.jenvman.2007.08.020
is less clear, however, there are other N related water quality issues, such as compliance with the nitrate-N limit (Nitrate Directive 91/676/EEC), and impacts of reduced-N on aquatic ecology. Excess inputs of either forms of the reduced N (NH3–N or NH4–N) can seriously impair aquatic ecology through direct toxicity (NH3) and diminished dissolved oxygen (due to oxidation of NH4) supply impacts upon invertebrates (Hooda et al., 2000b) and fish (Camargo and Alonso, 2006). N and P arise generally from intensive agriculture (Hooda et al., 2000a; Withers and Lord, 2002); however, their inputs from sewage treatment works can be equally important in densely populated catchments (Jarvie et al., 2006). Within rural catchments, livestock farming presents more complex input sources of nutrients and carbon rich substances into waters. Among these sources is runoff from farmyards which can be highly contaminated with a variety of substances, including nutrients and faecal indicator organisms (Edwards et al., 2008). Similarly inputs of ‘dirtywater’ from animal housing, including milk parlour washings or overflow of silage effluents can seriously impair receiving waters by contributing a cocktail of contaminants. Such inputs include dissolved oxygen depleting labile carbon rich waste and large amount of nutrients (Edwards and Hooda, 2008). Direct discharges of such effluents from animal housing areas can also contribute significant quantities of faecal bacteria and NH4–N (Monaghan and Smith, 2004). Together, these livestock farm effluents have been known to degrade ecological quality of receiving waters (Hooda et al., 2000b). Ecological status of waters has gained much more significance in recent years because of the Water Framework Directive (Directive 2000/60/EC), which places ecological quality protection at the centre of water management strategies. The connectivity between fresh- and coastal-waters means contaminants arising from inland sources reach the marine environment. It is thus largely catchment sources, both rural and urban, that need to be targeted in order to control contaminants transport to coastal waters. As point sources are relatively easy to identify and control, the diffuse agriculture sources are becoming increasingly significant. As a result of this, farm nutrient management is becoming an important tool to reduce nutrient losses
ARTICLE IN PRESS 534
Editorial / Journal of Environmental Management 87 (2008) 533–534
to waters by implementing best management practices (Monaghan et al., 2008). The special issue brings together current research that quantifies specific aspects of contamination and remediation of fresh and coastal waters. The paper topics have been selected to describe the issues, supporting research and finally management strategies. It is hoped that the issue makes a significant contribution to the understanding of microbial and nutrient contaminants for further improvement in water resource management, including ecological quality which is the mainstay in the Water Framework Directive.
References Camargo, J.A., Alonso, A´., 2006. Ecological and toxicological effects of inorganic nitrogen pollution in aquatic ecosystems: A global assessment. Environment International 32, 831–849. Edwards, A.C., Hooda, P.S., 2008. Farmyard point discharges and their influence on nutrient and labile carbon dynamics in a second order stream draining through a dairy unit. Journal of Environmental Management 87, 591–599. Edwards, A.C., Kay, D., McDonald, A., Francis, C., Watkins, J., Wilkinson, J.R., Wyer, M.D., 2008. Farmyards, an overlooked source for highly contaminated runoff. Journal of Environmental Management 87, 551–559. Goss, M., Richards, M., 2008. Development of a risk-based index for source water protection planning, which supports the reduction of pathogens from agricultural activity entering water resources. Journal of Environmental Management 87, 623–632. Hooda, P.S., Edwards, A.C., Anderson, H.A., Miller, A., 2000a. A review of catchment water quality concerns in livestock farming areas. The Science of the Total Environment 250, 143–167.
Hooda, P.S., Moynagh, M., Svoboda, I., Miller, A., 2000b. Macroinvertebrate as bioindicators of water pollution in streams draining dairy farm catchments. Chemistry and Ecology 17, 17–30. Jarvie, H.P., Neal, C., Withers, P.J.A., 2006. Sewage-effluent phosphorus: A greater risk to river eutrophication than agricultural phosphorus?. The Science of Total Environment 360, 246–253. Monaghan, R.M., Smith, L.C., 2004. Minimising surface water pollution resulting from farm-dairy effluent application to mole-pipe drained soils. II. The contribution of preferential flow of effluent to whole-farm pollutant losses in subsurface drainage from a West Otago dairy farm. New Zealand Journal of Agricultural Research 47, 417–428. Monaghan, R.M., de Klein, C.A.M., Muirhead, R.W., 2008. Prioritisation of farm scale remediation efforts for reducing losses of nutrients and faecal indicator organisms to waterways: a case study of New Zealand dairy farming. Journal of Environmental Management 87, 609–622. Stapleton, C.M., Wyer, M.D., Crowther, J., McDonald, A.T., Kay, D., Greaves, J., Wither, A., Watkins, J., Francis, C., Humphrey, N., Bradford, M., 2008. Quantitative catchment profiling to apportion faecal indicator organism budgets for the Ribble system, the UK’s sentinel drainage basin for Water Framework Directive research. Journal of Environmental Management 87, 535–550. Withers, P.J.A., Lord, E.I., 2002. Agricultural nutrient inputs to rivers and groundwaters in the UK: policy, environmental management and research needs. The Science of the Total Environment 282, 9–24.
P.S. Hooda Centre for Earth and Environmental Science Research, Kingston University London, Kingston upon Thames KT1 2EE, UK E-mail address: [email protected] 25 July 2007
Journal of Environmental Management 87 (2008) 533–534 www.elsevier.com/locate/jenvman
Editorial
Microbial and nutrient contaminants of fresh and coastal waters Water quality protection is important from both human health and environmental perspectives. Drinking water quality is an issue of global human health concern, principally due to water contamination with pathogens and potentially toxic chemicals. Contaminants in freshwater resources can arise from a variety of sources including those associated with the treatment and disposal of sewage and agricultural livestock wastes. Pathogenic contaminants from these mixed sources include viruses and bacteria such as Escherichia coli O157I and the protozoa Giardia and Cryptospordium parvum raising issues in terms of drinking water (e.g., Directive 98/83/EC) and recreational use such as bathing waters (Bathing Water Directive, 76/160/EEC). For example, the town of Walkerton (Ontario, Canada) experienced the largest waterborne disease outbreak in Canada (Goss and Richards, 2008), which was linked to the contamination of the water supply system with pathogens that originated in manure, resulting in 2300 cases of gastroenteritis and seven deaths (cf. Goss and Richards, 2008). Similar outbreaks of cryptosporidiosis in England and Scotland were attributed to slurry spreading or other cattle activities (cf. Hooda et al. 2000a). The Bathing Water Directive sets a number of mandatory microbiological and chemical standards which bathing waters should comply with. Within rural settings the major diffuse and point sources of microbial contamination are largely associated with livestock farming activities; however waters in catchments with no livestock or other apparent sources can be contaminated by wildlife sources (Hooda et al., 2000a). The compliance with microbiological standards can also be compromised in catchments with no obvious direct point or diffused sources, as discussed by Stapleton et al. (2008) where untreated sewage overflows accounted for 490% of the total microbial load. Clearly compliance with the Bathing Water Directive as well as for public health protection all potential sources need to be regularly assessed/ monitored in order to develop effective water quality management strategies. Nutrient enrichment, mainly with phosphorus (P) of freshwaters can cause excessive growth of algae, leading to general degradation of aquatic ecosystems, including loss of biodiversity. The role of nitrogen (N) in eutrophication 0301-4797/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.jenvman.2007.08.020
is less clear, however, there are other N related water quality issues, such as compliance with the nitrate-N limit (Nitrate Directive 91/676/EEC), and impacts of reduced-N on aquatic ecology. Excess inputs of either forms of the reduced N (NH3–N or NH4–N) can seriously impair aquatic ecology through direct toxicity (NH3) and diminished dissolved oxygen (due to oxidation of NH4) supply impacts upon invertebrates (Hooda et al., 2000b) and fish (Camargo and Alonso, 2006). N and P arise generally from intensive agriculture (Hooda et al., 2000a; Withers and Lord, 2002); however, their inputs from sewage treatment works can be equally important in densely populated catchments (Jarvie et al., 2006). Within rural catchments, livestock farming presents more complex input sources of nutrients and carbon rich substances into waters. Among these sources is runoff from farmyards which can be highly contaminated with a variety of substances, including nutrients and faecal indicator organisms (Edwards et al., 2008). Similarly inputs of ‘dirtywater’ from animal housing, including milk parlour washings or overflow of silage effluents can seriously impair receiving waters by contributing a cocktail of contaminants. Such inputs include dissolved oxygen depleting labile carbon rich waste and large amount of nutrients (Edwards and Hooda, 2008). Direct discharges of such effluents from animal housing areas can also contribute significant quantities of faecal bacteria and NH4–N (Monaghan and Smith, 2004). Together, these livestock farm effluents have been known to degrade ecological quality of receiving waters (Hooda et al., 2000b). Ecological status of waters has gained much more significance in recent years because of the Water Framework Directive (Directive 2000/60/EC), which places ecological quality protection at the centre of water management strategies. The connectivity between fresh- and coastal-waters means contaminants arising from inland sources reach the marine environment. It is thus largely catchment sources, both rural and urban, that need to be targeted in order to control contaminants transport to coastal waters. As point sources are relatively easy to identify and control, the diffuse agriculture sources are becoming increasingly significant. As a result of this, farm nutrient management is becoming an important tool to reduce nutrient losses
ARTICLE IN PRESS 534
Editorial / Journal of Environmental Management 87 (2008) 533–534
to waters by implementing best management practices (Monaghan et al., 2008). The special issue brings together current research that quantifies specific aspects of contamination and remediation of fresh and coastal waters. The paper topics have been selected to describe the issues, supporting research and finally management strategies. It is hoped that the issue makes a significant contribution to the understanding of microbial and nutrient contaminants for further improvement in water resource management, including ecological quality which is the mainstay in the Water Framework Directive.
References Camargo, J.A., Alonso, A´., 2006. Ecological and toxicological effects of inorganic nitrogen pollution in aquatic ecosystems: A global assessment. Environment International 32, 831–849. Edwards, A.C., Hooda, P.S., 2008. Farmyard point discharges and their influence on nutrient and labile carbon dynamics in a second order stream draining through a dairy unit. Journal of Environmental Management 87, 591–599. Edwards, A.C., Kay, D., McDonald, A., Francis, C., Watkins, J., Wilkinson, J.R., Wyer, M.D., 2008. Farmyards, an overlooked source for highly contaminated runoff. Journal of Environmental Management 87, 551–559. Goss, M., Richards, M., 2008. Development of a risk-based index for source water protection planning, which supports the reduction of pathogens from agricultural activity entering water resources. Journal of Environmental Management 87, 623–632. Hooda, P.S., Edwards, A.C., Anderson, H.A., Miller, A., 2000a. A review of catchment water quality concerns in livestock farming areas. The Science of the Total Environment 250, 143–167.
Hooda, P.S., Moynagh, M., Svoboda, I., Miller, A., 2000b. Macroinvertebrate as bioindicators of water pollution in streams draining dairy farm catchments. Chemistry and Ecology 17, 17–30. Jarvie, H.P., Neal, C., Withers, P.J.A., 2006. Sewage-effluent phosphorus: A greater risk to river eutrophication than agricultural phosphorus?. The Science of Total Environment 360, 246–253. Monaghan, R.M., Smith, L.C., 2004. Minimising surface water pollution resulting from farm-dairy effluent application to mole-pipe drained soils. II. The contribution of preferential flow of effluent to whole-farm pollutant losses in subsurface drainage from a West Otago dairy farm. New Zealand Journal of Agricultural Research 47, 417–428. Monaghan, R.M., de Klein, C.A.M., Muirhead, R.W., 2008. Prioritisation of farm scale remediation efforts for reducing losses of nutrients and faecal indicator organisms to waterways: a case study of New Zealand dairy farming. Journal of Environmental Management 87, 609–622. Stapleton, C.M., Wyer, M.D., Crowther, J., McDonald, A.T., Kay, D., Greaves, J., Wither, A., Watkins, J., Francis, C., Humphrey, N., Bradford, M., 2008. Quantitative catchment profiling to apportion faecal indicator organism budgets for the Ribble system, the UK’s sentinel drainage basin for Water Framework Directive research. Journal of Environmental Management 87, 535–550. Withers, P.J.A., Lord, E.I., 2002. Agricultural nutrient inputs to rivers and groundwaters in the UK: policy, environmental management and research needs. The Science of the Total Environment 282, 9–24.
P.S. Hooda Centre for Earth and Environmental Science Research, Kingston University London, Kingston upon Thames KT1 2EE, UK E-mail address: [email protected] 25 July 2007