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. Annex 1 

 specific water quality objectives 



1. Specifib Ohjectives. The specific water quality objectives for the 

 boundary waters of the Great Lakes System are as follows : 



(a) Microhiology. The o-eometiic mean of not less than five 

 samples taken over not more than a thirty-day period should not 

 exceed 1,000/100 millilitres total coliforms, nor 200/100 millilitres 

 fecal coliforms. Waters used for body contact recreation activities 

 should be substantially free from bacteria, fungi, or viruses that 

 may produce enteric disorders or eye, ear, nose, throat and skin 

 infections or other human diseases and infections. 



(b) Dissolved Oxygen. In the Connecting Channels and in the 

 upper waters of the Lakes, the dissolved osygen level should be 

 not less than 6.0 milligrams per litre at any time ; in hypolimnetic 

 waters, it should be not less than necessary for the support of fish- 

 life, particularly cold water species. 



(c) Total Dissolved Solids. In Lake Erie, Lake Ontario and the 

 International Section of the St. Lawrence Kiver, the level of total 

 dissolved solids should not exceed 200 milligrams per litre. In the 

 St. Clair River, Lake St. Clair, the Detroit River and the Niagara 

 River, the level should be consistent with maintaining the levels 

 of total dissolved solids in Lake Erie and Lake Ontario at not to 

 exceed 200 milligrams per litre. In the remaining boundary wa- 

 ters, pending further study, the level of total dissolved solids 

 should not exceed present levels. 



(d) Taste and Odour. Phenols and other objectionable taste and 

 odour producing substances should be substantially absent. 



(e) pH. Values should not be outside the range of 6.7 to 8.5. 



(f ) Iron (Fe) . Levels should not exceed 0.3 milligrams per litre. 



(g) Phosphorus (P). Concentrations should be limited to the 

 extent necessary to prevent nuisance growths of algae, weeds and 

 slimes that are or may become injurious to any beneficial water 

 use. 



^ (h) Radioactivity. Radioactivity should be kept at the lowest 

 practicable levels and in any event should be controlled to the 

 extent necessary to prevent harmful effects on health. 



2. Interim Ohjectives. Until objectives for particular substances and 

 effects in the classes described in this paragraph are further refined^ 

 the objectives for them are as follows : 



(a) Temperature. There should be no change that would ad- 

 versely affect any local or general use of these waters. 



(b) Mercury and Other Toxic Heavy Metals. The aquatic en- 

 vironment sjiould be free from substances attributable to munici- 

 pal, industrial or other discharges in concentrations that are toxic 

 or harmful to human, animal or aquatic life, 



(c) Persistent Organic Contaminants. Persistent pest control 

 products and other persistent organic contaminants that are toxic 

 or harmful to human, animal or acquatic life should be substan- 

 tially absent in the waters. 



(d) SettleaMe and Suspended, Materials. Waters should be free 

 from substances attributable to municipal, industrial or other dis- 

 charges that will settle to form putrescent or otherwise objection- 



