The speakers will address the differences between row crops and permanent pasture regarding the amount of sediment and pollutants that wind up in the Lake Rathbun and discuss the challenges of removing some substances from the water so that it meets their high standards for potability.

1. Rathbun Regional Water
Association, Inc.
Water Treatment Plant
Source Water Evaluation

2. Chariton River WTP Intake

3. Overview of Treatment

4. Principles of Operation
• Oxidation and Precipitation
• Coagulation
• Flocculation
• Sedimentation
• Filtration
• disinfection

5. SuperPulsating Clarifiers

6. Solids Contact Basins

7. Chemical Feed

8. Filtration

9. High Service

10. Analyzers

11. Performance Based Training
Turbidity Profile
Raw Max Sed Max Filter Combined
100.0
Turbidity (NTU)
10.0
1.0
0.1
0.0
Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11 Jul-11 Aug-11 Sep-11 Oct-11 Nov-11 Dec-11

12. Source Water Evaluation
1. Organics/Manganese
2. Taste and Odor
3. Turbidity
4. Alkalinity
5. Farm Chemical Application
6. Bacteria/Cryptosporidium

13. Organics and Manganese
• Often Bound together
• Removal contrast based on pH (TOC/Mn)
• Sodium Permanganate
• Rainfall events push organics into lake
– Leaves, trees, brush, etc.
• Lake stratification promotes Mn build up
• Low dissolved oxygen concentration
– New Caisson provide relief from lake bottom

14. 36 “ Screened Intake

15. Taste and Odor
• Spring flush of nutrients into lake
• Dry summers influence stratification
– Sunlight penetration due to settling
• Geosmin and Methoisoborneol -2 (MIB)
– Encapsulate in blue-green algae cell walls
– Release when cyanotoxins are present
• Phosphorus reduction can help

16. Turbidity
• Very low turbidity is hard to treat (< 5ntu)
• High turbidity can be expensive (>100ntu)
• Rathbun range is 3 – 500 ntu. Avg. is 25 ntu.
• Sediment removal is a great benefit.
• Rainfall events > 1” above and below intake
are detrimental to optimization.

17. Discharge 2010

18. Alkalinity
• Requirement for coagulation buffer
– 0.5 mg/L plus 35 mg/L residual
• Extreme flooding (2007-2008) downstream
• Rathbun uses Sodium Hydroxide to buffer
– 1.65 mg/L dosage to achieve 1 ppm residual

19. New Caisson

20. Farm Chemical Application
• Atrazine and Nitrogen
• Nearly eliminated since RLWA improvements
• Carbon caps on filters
• Powder Activated Carbon

21. Syngenta Atrazine

22. Bacteria/Cryptosporidium
• Manure Runoff
• Ecoli and Fecal Coliform
• Chlorine Demand
• 4-log removal of crypto
• Conservation practice to maintain low influent

23. Questions???
• mbraster@rrwa.net
• jbuckingham@rrwa.net
• (800) 233.8849
• www.rrwa.net
• www.rathbunlandwateralliance.blogspot.com