DISSOLVED ZINC

The measurements shown below were made at USGS station 01209710, located on the Norwalk River near the Perry Avenue bridge. All of the measurements are in micrograms per liter, as Zi. For details about the data, press here.

The highest reading, 50, occurred in 2/81, and the lowest, <1.0, in 9/97. All of the readings above 31 (11 percent of the samples), are shown in red and all that are below 5.0 (another 13 percent), are in blue.

 Averages by
Season and by
5-year Period:
 
(Overall = 15.2)
Jan-Mar22.9
Apr-Jun 13.2
Jul-Sep 8.49
Oct-Dec 19.5
1980-84 20.3
1985-89 18.8
1990-94 10.5
1995-99 10.2

YearJanFebMar AprMayJunJulAug SepOctNovDec
1980                   10 30 40
1981 40 50 30 10 10 10 10 10 10 20 10 40
1982 40 30 20 10 10 30 11 10 <10 10 24 20
1983 17   20 20 11 20 <3.0 10 10 20 31 30
1984 30   20 23 16 21 25 25 17 31 17 31
1985 30   50 15 17 19 8.0 17 9.0 23 21 31
1986 33   37 24 24 8.0 7.0 10 16 19 31 36
1987 33   15 14 21 17 8.0 10 <3.0 8.0 19 15
1988 27   15 12 16 13 11 11 14 6.0 21 35
1989     10 22 15 13 <10 5.0 3.0 17 14 41
1990 20   6.0 9.0 6.0 9.0 11 5.0 6.0 12 31 14
1991 14   5.0 14   13 5.0 4.0 10 6.0 14 13
1992 20   12 13 7.0 4.0 5.0 8.0 10 13   14
1993   12   12   3.0 2.0   8.0 5.0   9.0
1994   16   13   6.0 8.0 4.0 4.0 7   8
1995   12   9   8 6 4 17 11    
1996 19 18   8.0   12 6.0 5.0 6.0 9.0   9.0
1997   9.0   6.3   2.7 6.5 3.4 <1.0