Rock (Seminole County)

Florida LAKEWATCH Water Chemistry Summary

Location: Latitude 28°42'14", Longitude 81°22'5"

Period of record: 87 sampling dates; December 1, 1991 to December 30, 1999

Surface area (Shafer et al. 1986): 19 acres / 8 hectacres

Lake Region (Griffith et al. 1997): Crescent City/DeLand Ridges

Geologic formation (Brooks 1981):

The geology is dominated by coastal sand and shelly silty sand of the preglacial Pleistocene.

Physiographic region (Brooks 1981):

The water body lies in the Casselberry-Oviedo-Geneva-Chuluota Hills division of the Central Lake District.

Supplemental, unpublished water chemistry data, University of Florida.

Numbers reported below are the average for 1 month sampled:

pH

7.0

Sulfate (mg/L)

10.3

Total alkalinity (mg/L as CaCO3)

6.3

Calcium (mg/L)

4.4

Conductance (µS/cm @ 25 °C)

121

Magnesium (mg/L)

2.3

Color (Pt-Co units)

13

Sodium (mg/L)

12.0

Chloride (mg/L)

23.9

Potassium (mg/L)

0.9

Silicon (mg/L)

0.1

 

 

Long-term Florida LAKEWATCH Data

Numbers reported below are the minimum, average, and maximum value for the 87 months sampled:

 

Minimum

Average

Maximum

Long-term total phosphorus concentrations (µg/L)

6

9

17

Long-term total nitrogen concentrations (µg/L)

350

490

650

Long-term total chlorophyll concentrations (µg/L)

1.0

3.8

8.3

Long-term Secchi depth (ft)

6.5

10.6

13.9

1999 Florida LAKEWATCH Data

Numbers reported below are monthly averages calculated from 3 stations for total phosphorus (TP, µg/L), total nitrogen (TN, µg/L), chlorophyll (CHL, µg/L) and Secchi depth (SECCHI, ft) during 1999:

Date

TP (µg/L)

TN (µg/L)

CHL (µg/L)

SECCHI (ft

Jan-02-99

10

500

2.0

.

Jan-30-99

8

620

2.0

12.0

Feb-25-99

17

600

8.0

8.0

Mar-28-99

10

440

1.3

.

May-02-99

10

550

2.0

10.5

May-31-99

7

600

2.3

.

Jun-30-99

11

480

4.0

8.5

Jul-27-99

12

550

4.7

7.5

Aug-26-99

10

580

4.3

7.0

Sep-30-99

11

550

3.7

7.5

Oct-27-99

9

550

4.7

6.8

Nov-26-99

10

490

3.7

9.0

Dec-30-99

10

620

3.0

9.5

 

 

 

 

 

1999 Average

10

550

3.5

8.6

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