Nitrate-Nitrogen (Summer average, June - August)

              West Okoboji Lake

             East Okoboji Lake

Year

 

 

Principal

Investigator  

   

 

Sampling

Period

 

 

 

Number

of

lake sampling

sites

 

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

 

Year

 

 

Principal

Investigator

Sampling

Period

 

Number

of

lake sampling

sites

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

1971

Bachmann

6/14 to

8/30

6

36

<0.01

0.00

1971

Bachmann

6/23 to

8/30

5

31

0.06

0.01

1972

Bachmann

6/12 to

8/24

6

25

0.01

0.00

1972

Bachmann

6/1 to

8/24

5

25

0.07

0.01

1973

Bachmann

6/7 to

8/20

6

16

<0.01

0.00

1973

Bachmann

6/21 to

8/20

5

39

0.16

0.04

1987

Bachmann

6/2 to

8/13

6

65

0.10

0.00

NA

NA

NA

NA

NA

NA

1988

Bachmann

6/6 to

8/8

6

60

0.05

0.00

NA

NA

NA

NA

NA

NA

1989

Bachmann

6/4 to

8/6

6

59

0.06

0.00

NA

NA

NA

NA

NA

NA

1998

Lang

7/2 to

8/28

3

27

0.07

0.00

NA

NA

NA

NA

NA

NA

1999

CLAMP

6/17 to

8/25

6

36

0.04

0.00

1999

CLAMP

6/17 to

8/31

5

30

0.31

0.09

2000

CLAMP

6/7 to

8/31

6

42

 

0.06

0.00

2000

CLAMP

6/2 to

8/20

5

35

0.15

0.02

2001

CLAMP

6/14 to

8/22

6

36

0.09

0.00

2001

CLAMP

6/10 to

8/22

5

25

0.29

0.06

2002

CLAMP

6/5 to

8/26

6

42

0.07

0.00

2002

CLAMP

6/5 to

8/28

5

35

0.15

0.02

2003

CLAMP

6/11 to

8/20

6

36

0.04

0.00

2003

CLAMP

6/8 to

8/21

5

30

0.28

0.05

 

                Big Spirit Lake

                Upper Gar Lake

Year

 

 

Principal

Investigator  

   

 

Sampling

Period

 

 

 

Number

of

lake sampling

sites

 

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

 

Year

 

Principal

Investigator

Sampling

Period

 

Number

of

lake sampling

sites

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

1971

Bachmann

6/21 to

8/26

5

20

0.02

0.00

1971

Bachmann

7/15 to

8/22

1

5

0.07

0.03

1972

Bachmann

6/5 to

8/23

5

20

0.01

0.00

1972

Bachmann

6/1 to

8/25

1

5

0.07

0.02

1973

Bachmann

6/26 to

8/30

5

30

0.01

0.00

1973

Bachmann

6/21 to

8/15

1

5

0.19

0.11

1999

CLAMP

6/18 to

8/20

5

25

0.11

0.01

1999

CLAMP

6/17 to

8/25

1

5

0.24

0.14

2000

CLAMP

6/7 to

8/31

5

35

0.06

0.00

2000

CLAMP

6/2 to

8/25

1

7

0.10

0.02

 

2001

CLAMP

6/8 to

8/20

5

30

0.14

0.03

2001

CLAMP

6/8 to

8/22

1

6

0.40

0.14

2002

CLAMP

6/7 to

8/28

5

35

0.09

0.00

2002

CLAMP

6/5 to

8/28

1

7

0.10

0.01

2003

CLAMP

6/5 to

8/19

5

29

0.07

0.00

2003

CLAMP

6/12 to

8/30

1

6

0.10

0.01

 

              Lake Minnewashta

                Lower Gar Lake

Year

 

 

Principal

Investigator  

   

 

Sampling

Period

 

 

 

Number

of

lake sampling

sites

 

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

 

Year

 

 

Principal

Investigator  

   

 

Sampling

Period

 

Number

of

lake sampling

sites

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

1971

Bachmann

7/15 to

8/22

1

5

0.06

0.02

1971

Bachmann

7/15 to

8/22

1

5

0.09

0.02

1972

Bachmann

6/1 to

8/25

1

5

0.05

0.01

1972

Bachmann

6/1 to

8/25

1

5

0.19

0.03

1973

Bachmann

6/21 to

8/15

1

5

0.14

0.08

1973

Bachmann

6/21 to

8/15

1

5

0.28

0.13

1999

CLAMP

7/14 to

8/25

1

4

0.09

0.02

1999

CLAMP

7/14 to

8/25

1

4

0.25

0.05

2000

CLAMP

6/2 to

8/25

1

7

0.14

0.02

2000

CLAMP

6/2 to

8/25

1

7

0.21

0.05

2001

CLAMP

6/8 to

8/22

1

6

0.35

0.12

2001

CLAMP

6/8 to

8/22

1

6

0.33

0.11

2002

CLAMP

6/5 to

8/28

1

7

0.10

0.01

2002

CLAMP

6/5 to

8/28

1

7

0.40

0.18

2003

CLAMP

6/12 to

8/30

1

6

0.09

0.02

2003

CLAMP

6/12 to

8/30

1

6

0.20

0.06

 

              Little Spirit Lake

                Center Lake

Year

 

 

Principal

Investigator  

   

 

Sampling

Period

 

 

 

Number

of

lake sampling

sites

 

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

 

Year

 

 

Principal

Investigator  

   

 

Sampling

Period

 

Number

of

lake sampling

sites

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

1971

Bachmann

7/16 to

7/22

1

2

0.03

0.01

NA

NA

NA

NA

NA

NA

1972

Bachmann

7/16 to

8/25

1

3

0.04

0.01

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

1999

CLAMP

 

7/18 to

8/29

2

7

0.17

0.02

2000

CLAMP

6/24 to

8/19

2

10

0.18

0.01

 

2000

CLAMP

6/11 to

8/13

2

6

0.17

0.02

2001

CLAMP

6/9 to

8/11

2

10

0.52

0.23

2001

CLAMP

7/8 to

8/25

2

8

0.18

0.01

2002

CLAMP

6/5 to

8/23

2

14

0.30

0.05

2002

CLAMP

6/9 to

8/19

2

12

0.20

0.02

2003

CLAMP

6/11 to

8/18

2

12

0.25

0.04

2003

CLAMP

6/15 to

8/31

2

12

0.15

0.02

 

              Silver Lake

 

Year

 

 

Principal

Investigator  

   

 

Sampling

Period

 

 

 

Number

of

lake sampling

sites

 

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

 

 

 

 

 

 

 

1999

CLAMP

 

7/30 to

8/26

4

12

0.46

0.15

 

 

 

 

 

 

2000

CLAMP

6/6 to

8/22

4

23

1.00

0.21

 

 

 

 

 

 

2001

CLAMP

6/5 to

8/28

4

28

3.48

0.39

 

 

 

 

 

 

2002

CLAMP

6/11 to

8/20

4

24

0.60

0.12

 

 

 

 

 

 

2003

CLAMP

6/10 to

819

4

24

0.92

0.17

 

 

 

 

 

 

 

              Elk Lake

                Trumbull Lake

Year

 

 

Principal

Investigator  

   

 

Sampling

Period

 

 

 

Number

of

lake sampling

sites

 

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

 

Year

 

 

Principal

Investigator  

   

 

Sampling

Period

 

Number

of

lake sampling

sites

 

Total

number

of

samples

collected

Avg

NO3

 

(mg/L)

SE

2000

CLAMP

6/20 to

8/16

1

3

0.25

0.07

2000

CLAMP

6/20 to

8/16

1

3

0.87

0. 36

2001

CLAMP

6/13 to

8/16

1

3

0.78

0.54

2001

CLAMP

6/13 to

8/16

1

3

2.69

2.58

2002

CLAMP

7/22 to

8/26

1

2

0.22

0.03

2002

CLAMP

7/22 to

8/26

1

2

0.12

0.00