Broward Testing Laboratory Testing
Broward Testing Laboratory, LTD.
Technical Report – Project #98/26 – September 03, 1998

Method:
1. The system was assembled according to the supplied instructions, and then given a cursory decontamination by wiping all internal surfaces with isopropyl alcohol.

2. To confirm general decontamination, 99 mL of a sterile buffer were introduced to the lower bucket. The bucket was rotated and tipped to allow the buffer to contact as much surface area as possible. A sample was then taken for Coliform analysis through the bottom spigot.

3. The top bucket was filled with tap water to condition the filters and rinse the carbon fines. A sample of the tap water was taken at this time and analyzed for free chlorine.

4. The holding bucket was filled with tap water and dechlorinated with a small spatula full of Sodium Thiosulfate. The solution was stirred and allowed to sit, then was analyzed for free chlorine. Free chlorine was not detected.

5. The dechlorinated tap water in the holding bucket was then inoculated with a laboratory strain of E. coli (IDDEXX Laboratories, Lot S1615). A sample was taken for analysis. The solution was stirred with a sterile pipette and allowed to sit for 30 minutes.

6. Five milliliters of household bleach (Clorox brand) was added to the bacteria spiked water and stirred with the sterile pipette. A sample was analyzed for free chlorine and was found to be above the analytical range of the analysis (0.1 to 3.0 PPM free chlorine). The approximate concentration of free chlorine was interpolated to be around 5 PPM. The contents of the bucket were allowed to sit for an additional 30 minutes.

7. During this time the water in the top bucket was “conditioning” the filters and filling the lower bucket. After about 2/3 of the water was transferred, the lower bucket was emptied. Carbon fines were noted in the filtrate. The last third was again allowed to flow into the lower bucket.

8. The remainder of the water from the top bucket (minus a holdup volume of approximately 2 liters) filtered into the lower bucket. No more fines were noted. This water was drained to waste through the spigot.

9. After 30 minutes of “sanitation” a sample was taken from the holding bucket for free chlorine analysis. The free chlorine was found to be 1.45 PPM.

10. The water from the holding bucket was poured into the top bucket and filtration started.

11. When about 2/3 of the lower bucket was filled. A final sample was taken for analysis.

Results:
Analysis for Free Chlorine was performed via method 2540C, Standard Methods 18th ed. Analysis for Coliform Bacteria was performed via method 9222B, Standard Methods 18th ed.

Sample Point
Free Chlorine in PPM
Coliforms in CFU per 100ml
Background
N/A
BDL
Tap Water
0.2
BDL
Dechlorinated Tap Water
BDL
N/A
Challenge
N/A
4 x 10 to the 4th power
Sanitation
>3.0
N/A
After 30 minutes
1.45
N/A
Filtrate
0.2
BDL
*PPM = Parts Per Million *CFU = Colony Forming Units
*N/A = Not Analyzed *BDL = Below Detectable Levels (<0.1 PPM)


Conclusion:
Eagle Spring’s Mission Filter proved effective in sanitizing 5 gallons of dechlorinated tap water that had been inoculated with E. Coli to a level of 4 x 104 CFU per 100 ml. After chlorination with 5 ml of household bleach and contact time of 30 minutes, the product water had no detectable Coliform bacteria and a free chlorine level of 0.2 mg/L.