Columbia County: Environmental Health

Impact of TS Debby in North Florida: An Observational Study Concerning Levels of

Total Coliform Bacteria and E. coli in Water Supply Systems

byDavid H Boniche

Background: Tropical Storm Debby• June 23-June 27, 2012• Mean Rainfall: 15 inches• Flash Flooding• $20 million damage in

Columbia County, FL• Potential Negative Impacts

on Floridian Aquifer and Water Supply Systems

Source: Hydrometeorological Prediction Center , July 2012,. Author: David Roth.

Background: FL Water Supply Systems

• DEP: Community Water Systems, Transient-Non Community, and Non-Transient Non-Community (SDWA)(80%).

• DOH: Limited-Use (381.0062 F.S/ Ch. 64E-8 F.A.C)

• Unregulated: Private Wells (Single-Family)

Objectives

• Assess the impact between a natural disaster (TS Debby) and the potential environmental health effects (water quality in drinking water supply systems).

• Analyze the stability of drinking water supply systems with a special emphasis on the vulnerability of Private Wells towards contamination when faced with a natural disaster (such as TS Debby).

Methods: Total Coliform Bacteria and E coli Test

• Observational Study of Archived and Ongoing Coliform Test Data in Columbia and Nearby Counties.

• Sample sets: - January 9, 2012- November 1, 2012 (all supply types)

(n = 4,714)- Period involving TS Debby (June 25, 2012 – August 16,

2012; only private wells) (n =1,338)- First-time submissions of private wells during the

period involving TS Debby. (n = 527)

Methods: Standard Method #9223 B

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 440

20

40

60

80

100

120

Results: Presence of Total Coliform in 2012 for All Supply Types

Coliform

Week in 2012

Sam

ple

Po

siti

ve

2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 440

5

10

15

20

25

Results: Presence of E Coli in 2012 for All Supply Types

E coli

Week in 2012

Sam

ple

Po

siti

ve

Methods

• Coliform Test compared with Spatial Data: Rainfall Dispersion, Recharge Potential, and Flood Zones (ArcGIS Geocoding)

Results: Total Coliform and E coli

Supply Type Sample Number

Failure rate E coli

Private 28% 45% 7%

CWS 18% 2% 0%

2012: n = 4,714

8 week Period (TS Debby): n = 1,338 Supply Type Sample

Number Failure rate E coli

Private 52% 56% 10%

CWS 12% 1.7% 0%

8 Week Period (TS Debby) (First-Time): n = 527

Supply Type Failure rate E coli

Private 55% 11.9%

Discussion

• High rates of contamination align with areas of high rates of sample submissions

• Observational Study: data is a function of sample submissions

Discussion

• Strengths: Coliform Test, Inspiration for Future Studies

• Limitations: Premature Negatives, Observational Study

Implications: MPH Competencies

• Applying laws and regulations that protect health and ensure safety

• Specify approaches for assessing, preventing, and controlling environmental hazards that pose risks to human health and the environment.

Acknowledgements

• John Lednicky (University of Florida)• Sallie Ford (Columbia County Health Dept)• Paul Muller (Columbia County Health Dept)• Megan Wetherington (Suwannee River Water

Mgt District)• Bebe Willis (Suwannee River Water Mgt District)

Thank You