3—Turbidities.
Average by Months.
(United States Geological Survey Standard.)

Month. Great Falls. Reservoirs: Dalecarlia Outlet. Gerogetown Outlet. McMillan Park Outlet. Filtered water. Max. Ave. Max. Ave. Max. Ave. Max. Ave. Max. Ave. 1905. October 100 36 40 21 32 18 20 11 4 1 November 35 19 34 19 22 14 14 11 3 1 December 1,500 199 250 84 150 74 95 39 14 6 1906. January 700 94 180 60 120 60 85 52 20 12 February 120 45 85 41 55 29 35 22 5 3 March 1,750 272 350 181 120 56 90 46 8 6 April 1,270 167 180 72 95 58 75 46 12 7 May 600 56 50 20 45 16 34 10 3 2 June 1,700 303 500 125 450 94 180 41 13 2 July 1,000 130 180 54 150 47 250 43 13 3 August 1,530 375 250 112 95 66 65 45 5 2 September 120 33 180 34 95 28 75 25 7 2 October 1,025 127 110 37 60 24 55 21 1 1 November 160 27 75 20 45 16 24 13 1 1 December 600 69 110 31 80 28 80 26 8 2 1907. January 400 135 150 70 110 75 70 53 11 7 February 55 26 26 15 36 16 40 17 5 2 March 950 248 180 77 130 70 90 57 7 4 April 200 47 80 33 60 30 45 24 4 2 May 130 29 40 18 26 15 14 9 1 1 June 400 104 160 48 75 32 40 18 1 1 July 600 114 130 61 78 47 45 31 1 1 August 800 73 130 35 85 26 30 14 1 0 September 600 129 ^{1 1} 150 51 70 28 1 0 October 75 32 public@vhost@g@gutenberg@html@files@27632@[email protected]#footnote_b1" class="pginternal"