Water Quality Assessment in the Salt Creek Watershed

Acknowledgments

I would like to thank the Office of the Vice President of Academic Affairs for

sponsoring this research through the Muskie Summer Fellowship Program. I

would also like to thank my mentor Dr. Lois Zook-Gerdau, and Kylene Wilson of

the Muskingum Soil and Water Conservation District.

Rachel E. Hentz Environmental Science Program

Muskingum University

References

http://www.water-research.net/watrqualindex/

Parameters Tested

Water quality was assessed by measuring

9 different physical and chemical factors. The

factors and their weights in the overall WQI are

given below:

Dissolved Oxygen 0.17

Fecal Coliforms 0.16

pH 0.11

BOD 0.11

ΔT 0.10

Phosphates 0.10

Nitrates 0.10

Turbidity 0.08

TDS 0.07

Conclusions

Despite the relatively small improvement in the WQI average between

2005 and 2010, statistical analysis using the t-test shows that the null

hypothesis is not confirmed at the 99.9% confidence level, indicating that the

improvement in water quality in 2010 vs. 2005 is statistically significant.

Samples should be taken in subsequent years to see if this trend continues.

Results for 2010 Water Measurements

The vast majority of samples fell into the “Medium” category, between 50-

70 on the WQI. All other sites were in the “Good” category (39 out of 90). No

samples were Poor or Very Poor.

Results for 2010 Water Measurements

The Watershed previously assessed in the summers of 2003-2005 did

not include measurements of BOD, ΔT and turbidity so WQI values were

calculated without these factors. A t-test was performed on 2009 data to

determine if 6-factor WQI values were significantly different than 9-factor WQI

values. The two sets of WQI calculated were not statistically different at the

95% confidence interval, therefore the validity of the 6-factor method used in

prior years was confirmed.

nitrates, ammonia, total suspended solids, pH, temperature, conductivity, dissolved

oxygen, total phosphorus, and barometric pressure. The National Sanitation

Foundation's water quality index method was modified to produce water quality index

values for sites within the watershed over a seven-year period. Water quality index

values did not show temporal and spatial trends. Water quality index values were

also found to be independent of precipitation and temperature measures. High levels

of fecal coliform were responsible for the majority of the low water quality index

assignments within the watershed. The first three years, water quality assessment

led to the development of a watershed management plan for the Salt Creek areas

and the subsequent award of a 319 implementation grant to improve water quality in

the watershed. Results of the water quality assessment are presented.

Muskingum Soil and Water

Conservation District

Water Quality Index The National Sanitation Foundation

developed an Index that converts 9 indicators

of water quality, given above, into an overall

ranking of Excellent, Good, Medium, Poor, and

Very Poor for the sample to gauge the overall

water quality. All the measurements were

converted into the appropriate units, and then

compared to the corresponding water quality

index ranking.

Map of the Sample

Sites in the Salt Creek

Watershed

Abstract The Salt Creek Watershed Project began in 2003 with annual

assessment of several key water quality indicators measured

multiple times at thirty one representative sites within the

watershed. The parameters measured were fecal coliform,