River Boyne Water Quality Management Plan - EPA

River Boyne Wakr Quality Mnnngment PlanMeasures contained in programmes for protection of the ecological quality of water will have regardto best environmental practices and best available technology not entailing excessive cost(BATNEEC), implemented according to the "pollutor pays" principal. This approach differs from thehistorical method of determining an assimilative capacity which involved estimation of the maximumamount of waste which could be discharged to a river system before the particular water qualitystandard would be exceeded.Nevertheless, the approach to be adopted in the plan is to set appropriate standards in terms of a rangeof relevant parameters defined in the various Directives and Regulations. The minimum standardsrequired for eMuent discharges can then be determined on the basis of existing background levels ofa pollutant and the available dilutions (based on 95 percentile low flow and the appropriate standard).Specific standards are specified hereunder in respect of five key water quality parameters for waterswhich-zre to comply with salmonid standards:-Dissolved Oxygen (D.O.)0 S day Biochemical Oxygen Demand (BODj)oOxidised Nitrogen&rho Phosphate/Total Phosphate'The five parameters give a measure of the or organic biodegradable waste which arc thepredominant type of waste generated an.$A&%harged + :W in the catchment. Standards for otherparmeters shall be those set out in E.U. %&&tives and National Regulations sumn~arised in Chapter4 and Tablc 4.11, as updated from time t&me..*-cThe standards for the five key parard~%rs are specified in percentile limits as follows:-Dissolved Oxygen (D.O.)99.9percentile limit : equal to or greater than 4 alg/l0295percentile limit : equal to or greater ihan 6 mgh'02SUpercentile limit : equal to or greater than 9 mng/l02Where dissolved oxygen levelsfall below 6 tng/l02 investigations will be instihrted todetermine the causeFive day Biochemical Oqgen Demand (BODg)For inspection purposes only.Consent of copyright owner required for any other use.95percentile limit : equal to or less than -5 n~g/ljopercentile limit : equal to or less than 3 mg/lEPA Export 26-07-2013:17:27:02