715 



TABLE 2— ANNUAL PHOSPHOROUS LOADINGS AND REDUCTIONS IN LOADINGS TO LAKE ONTARIO 

 (INCLUDING THE NIAGARA RIVER) 



[Short tons per year] 



1971 1972 1973 1974 1975 1976 



UnitedStates: 



Baseload 



Reduction 



Residual load 



Canada: 



Baseload 



Reduction 



Residual load 



Input from Lake Erie 



Totals: 



Baseload 



Reduction 



Residual load 18,000 17,800 16,700 15,300 13,900 10,000 



5. Reservation. The amounts shown as "residual loads" in Tables 1 

 and 2 above do not constitute allocations to the two countries, but rep- 

 resent anticipated results of municipal and industrial waste reduction 

 and detergent phosphorus control programs. 



6. Refinement of Data. The residual loads are based upon best avail- 

 able data. The Parties, in cooperation with the State and Provincial 

 Governments and with the International Joint Commission, shall con- 

 tinue to refine these estimates to ensure a comparable data base. These 

 estimates are subject to revision upon agreement by the Parties to re- 

 flect future refinement of the data. 



7. Objective of Programs. The objective of the foregoing programs 

 is to minimize eutrophication problems in the Great Lakes System. It 

 is anticipated that successful implementation of these programs will 

 accomplish the following results, which are of critical importance to 

 the success of the joint undertaking to preserve and enhance the qual- 

 ity of the waters of the Great Lakes System : 



(a) Restoration of year-round aerobic conditions in the bot- 

 tom waters of the central basin of Lake Erie ; 



(b) Reduction in present levels of algal growth in Lake Erie ; 



(c) Reduction in present levels of algal growth in Lake On- 

 tario, including the International Section of the St. Lawrence 

 River; 



(d) Stabilization of Lake Superior and Lake Huron in their 

 present oligotrophic state. 



It is nevertheless recognized that additional measures and programs 

 may be required to minimize eutrophication problems in the future. 

 Available evidence suggests that reductions in phosphorus loadings to 

 achieve a net discharge to Lake Erie in the range of 8,000 to lljOOO 

 tons per year may be required to bring about mesotrophic conditions 

 in this lake. 



8. Reductions for Upper Lakes. The Parties, in consultation with 

 the State and Provincial Governments and with the International 

 Joint Commission, shall within one year from the entry into force 

 of the Agreement determine the gross reduction in inputs of phos- 



