River Boyne Water Quality Management Plan - EPA

Rivcr Boync Walcr Quality Monagemmt PlanTABLE 5.5PLANTSBOYNE TO NAVAN WEIR - PHOSPHATE LOAD FROM SEWAGE TREATMENTLisdoran Conference Centreo\This approach neglects the uptake of &bsphate in vigorous plant and algal growth on sections ofriver channel, downstream of waste,&er in-flows. This pattern had already been identified whenconsidering the biotic status, disaved oxygen levels and the BOD levels in the river system.Examples include the River Boyne downstream of Edenderry and downstream of Trim, the Kinnegadriver downstream of Kinnegad, etc.For inspection purposes only.Consent of copyright owner required for any other use.The phosphate levels recorded in the river system (Appendix 3) show wide variations at each site.High concentrations at low flow conditions in summer weather are most likely to result in excessivealgal and plant growth. Small sluggish rivers are partic.ularly vulnerable. Rivers showing very highaverage values are the Clady, Deel, Delvin, Kinnegad, Knightsbrook, Mattock, Moynalty, Athboy andlocally on the Kells/Blackwater and main Boyne channel itself.A survey of plant and algal growth was carried out in the stretch of river from Navan Weir (Station1700) to Broadboyne Bridge (2000), approximately Skm downstream, during the summer of 1989.During this period, river flows were low, estimated at less than 95%ile flow. Water temperature, lowriver flow and sunlight penetration provided optimum growth conditions.The results of the field survey are depicted in Fig. 2. Algal growth varied from approximately 0% to80% and macrophyte growth varied from approximately 3% to 87%.EPA Export 26-07-2013:17:27:01