96 



Appendices to Fortieth Annual Report 



ruay also quote from an earlier passage (p. 12) : — " There are three great 

 subjects for all of which, in our opinion, the watershed is the proper 

 administrative area, i.e. Pollution, Water Supplies, and Fisheries. If 

 it were possible to give adequate representation to all the interests 

 concerned in one body, we should have a Board of great influence 

 capable of interfering authoritatively in all matters affecting the 

 district, while by the formation of separate committees the administra- 

 tion of each of the subjects above named might be left in the hands of 

 representatives best qualified to carry it on. The Government alone 

 can decide whether anything of this kind is practicable, but we have 

 thought it right to make the suggestion to mark our sense of the 

 interdependence of the different interests specially concerned in the 

 preservation of the purity of our rivers." 



The position advocated by the Sewage Disposal Commission may 

 be indicated from the three first headings of their conclusions (Final 

 Report, p. 11) : — 



" (a) The law should be altered so that a person discharging sewage 

 matter into a stream shall not be deemed to have committed 

 an offence under the Rivers Pollution Prevention Act, 1876, 

 if the sewage matter is discharged in a form which satisfies 

 the requirements of the prescribed standard. 



" (b) The standard should be either the general standard or a special 

 standard which will be higher or lower than the general 

 standard as local circumstances require or permit. 



"(c) An effluent in order to comply with the general standard must 

 not contain as discharged more than three parts per 100,000 

 of suspended matter, and with its suspended matters 

 included must not take up at 65 F (18 3 C) more than 2 0 

 parts per 100,000 of dissolved oxygen in five days. This 

 general standard should be prescribed either by statute or 

 by order of the Central Authority, and should be subject to 

 modifications by that Authority after an interval of not less 

 than ten years." 



The decision to deal with the question by the establishment of 

 standards of purity consisting of a general standard, with power to make 

 special standards to suit special cases, was arrived at after mature 

 consideration. 



Salmon Passes. 



To test the success of the Tummel Pass, to which reference has 

 repeatedly been made, the Tay District Board caused a trap to 

 be inserted at the top of the pass for some weeks during the three last 

 summers. 



In 1919, from 10th June to 17th June, with a height of water ranging 

 from 1 ft. 3 in. to 2 ft. 11 in., 83 fish ascended. 



In 1920, from 6th to 30th June, in water falling from 2ft. 7 in. to 

 1 ft. 5 in., 47 fish ascended; 20 fish were also observed to ascend the 

 fall. 



In 1921, from 8th to 31st May, in a rising water from 2 ft. 2 in. to 

 3 ft. 3 in., 135 fish ascended, but on four days none was observed owing 

 to an accident to the heck. The maximum daily number was 15, the 

 minimum 3. 



It would appear that when there is less than about 18 inches of 

 water in the pass, the fish take the fall rather than the pass, but the 

 experiment was sufficient to prove the value of the pass. 



