Farmyard point discharges and their influence on nutrient and labile carbon dynamics in a second order stream draining through a dairy unit

Phosphorus species and fractionation – Why sewage derived phosphorus is a problem

“…As shown in Table 2, agricultural inputs to water bodies from field runoff contains a high percentage of PP, and TDP concentrations are significantly different from SRP (Jarvie et al, 2006;Hooda et al, 1997;Edwards and Hooda, 2008). This higher proportion of PP in agricultural source P, and the greater proportion of dissolved organic P within the TDP fraction, means overall a lower fraction of TP is bioavailable than that from STW derived TP where SRP is the dominant species.…”

“…Thus, it is apparent that treated sewage wastewaters inputs present greater risk than agricultural runoff for similar amounts of total P released to river system, although other forms of agricultural input such as runoff from livestock hard-standing may be high in bioavailable P (Edwards and Withers, 2008;Edwards and Hooda, 2008). An additional factor in terms of STW inputs is their continuous nature, unlike agricultural runoff which is both transported and diluted by precipitation events.…”

“…leaching through field drains, wastewater runoff from farm buildings housing livestock or dairy and septic tank discharges. This is a significant source, but it generally represents a small proportion of the total amount of P derived from agriculture (Edwards and Hooda, 2008).…”

A cross-disciplinary toolkit to assess the risk of faecal indicator loss from grassland farm systems to surface waters

“…So it follows that a high E. coli source area will be cancelled out if it is located within a landscape of low transfer risk (e.g. the landscape acts as a 'safety-net'), but infrastructural controls will also play a bearing and should be consulted as a third risk criterion allowing for connectivity via artificial routes in the landscape Edwards and Hooda, 2008). Similarly, the degree to which obstacles prevent a farmer from taking action to limit pollution are accounted for within the framework.…”

Microbial and nutrient contaminants of fresh and coastal waters

“…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 NH 4 -N ( Monaghan and Smith, 2004).…”