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River Boyne Water Quality Management Plan - EPA

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<strong>River</strong> Boync Walrr Qualify blanagrmmt <strong>Plan</strong>Phosphates, expressed as mg/l P, are particularly important in terms of eutrophication. Excessivelevels cause serious eutrophication, particularly in lakes, though rivers with poor flow regime are alsoaffected. This is associated with algal blooms and diurnal variation in oxygen levels due tophotosynthesis in daytime and respiration at night. Phosphates are abundant in organic wastes fromwastewater and agricultural run-off.A value in the order of 0.2 mgn as PO4, equivalent to 0.0652 mg/l as P., is indicated in thesalmonidDirective as a general guide to prevent eutrophication. However, its impact is dependent on a range offactors, specific to each waterbody. All waterbodies have a threshold limit having regard to waterturnover and values above the threshold can lead to high algal growth and plant crop, particularly infavourable weather conditions. The surface water standard for abstractions has a limit of 0.7 mgll asP2O5, equivalent to 00.3mg/l as P (S.I. 294).Suspended SolidsSuspended solids measured as mg/l, are solids suspended in the water column which may settleslowly or remain in suspension. These solids may consist of algae, sewage solids or other particulatematerials, either inert or organic. The presence of suspended solids.interferes with aquatic plant lifedue to reduced light penetration, damaging fish life and causivgbuild up of material on the beds.The standard for salmonid waters is less than or equal to ~5m$~solids.*QThe co~lductivity of a waterbody is a measure @t+,....y to cany electric current and varies with theG ITnumber and type of ions contained in the @$body. It is of no health significance, but provides auseful indication of the magnitude of dis@ &l solids present and also a useful indication of hardnessand alkalinity. It is usually determined .id? 71 e field with a portable meter and units of measurementare pslcm at 2S0 or 20" as there is sodvariation on the temperature used. There is no standard forSalmonid waters.c+ YFor inspection purposes only.Consent of copyright owner required for any other use.The pH of a solution indicates whether it is acidic or basic and by definition is the negative logarithmof the hydrogen ion concentration. It is expressed on a scale from 0-14 with 7 being neutral, above 7alkaline and below 7 acidic. The normal range forfreshwaters is 6.5-8.0. The standard for Salmonidwaters is between 6 and 9. It can be measured conveniently in the field using a portable meter. Thereis no direct health significance but it is very important environmental parameter as it affects thebehaviour of other substances. Extremes of pH can cause fish morality and corrosion of metalfixtures, pipes etc. Short-term fluctuations in pH are usually associated with severe eutrophication.TemperatureTemperature is a very important parameter principally due to its relationship with other constituents,most notably dissolved oxygen. The normal temperature ranges in Irish freshwaters are from freezingpoint in winter to occasional summermaxima in the order of 25°C. Elevated temperatures may haveadverse effects on aquatic life and the standards for Salmonid waters are outlined in Table 5.1. Theunit of measurement is deg.C and measurement is usually carried out on site.<strong>EPA</strong> Export 26-07-2013:17:27:01

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