River Boyne Water Quality Management Plan - EPA

River Boyne Walcr Quality Management PlanFaecal ColiformsEscherichia coli is a coliform bacteria found in the intestine of both humans and animals. Itspresence indicates waste of faecal origin and the possibility that pathogenic or disease causingbacteria may be present. There are health risks associated with their presence in waterbodies andconsequently strict standards are in force regarding drinking waters and waters used for water contactsports such as swimming. They are a useful indication of sewage contamination and their presence inhigh numbers would infer recent sewage contamination. Coliform organisms die off over time andthe rate of die-off is much greater in saltwater than in freshwaters. There is no standard for salmonidwaters. Standards for designated bathing waters and for surface waters used for abstraction are givenin Table 4.1 1. Coliforms are usually measured as faecal coliforms or total colifoms. Faecalcoliforms are of faecal origin, whereas total coliforms are all coliform bacteria present, includingthose from soil and other sources.Chlorides occur naturally in all waters and the concentrations vary widely depending on the proximityto seawater. In freshwaters, natural sources include soil and rock formations. Sewage contains largeamounts of chlorine and high chlorine levels may indicate sewage contamination. Natural levels forfreshwaters are in the order of 15-35 mgll Cl. There are no stqdards for salmonid waters ands:andards for drinking water are concerned with taste rather than,@%city. Standards for total residualchlorine in fish waters, however, are tight, equivalent to 0.~03@$l Cl.Hydrogen S~Iphides.& ,$Hydrogen Sulphide is developed in sewage obic conditions, for example in pipe bedsediment5 or pipe wall slimes in foul/comb~.i$3ewers. It can be flushed out at storm overflows atthe onset of storm conditions and is hiwgtaYi:@xic to aquatic life. However, it is difficult to detect,being very quickly oxidised..Q\.*Pltysico-Cltemical Parameter ~ an~p'~A-ol- *.For inspection purposes only.Consent of copyright owner required for any other use.Tables 5.3 summarise the recent water quality history of the River Boyne main channel, and its'tributaries giving maximum, minimum and mean values. These summary tables illustrate the waterquality ranges in the Boyne River system.EPA Export 26-07-2013:17:27:01