Rathbun Regional Water Association, Inc.

Water Treatment PlantSource Water Evaluation

Chariton River WTP Intake

Overview of Treatment

Principles of Operation

• Oxidation and Precipitation• Coagulation• Flocculation• Sedimentation• Filtration• disinfection

SuperPulsating Clarifiers

Solids Contact Basins

Chemical Feed

Filtration

High Service

Analyzers

Performance Based Training

Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11 Jul-11 Aug-11 Sep-11 Oct-11 Nov-11 Dec-110.0

0.1

1.0

10.0

100.0

1000.0

Turbidity ProfileRaw Max Sed Max Filter Combined

Tu

rbid

ity

(NT

U)

Source Water Evaluation

1. Organics/Manganese2. Taste and Odor3. Turbidity4. Alkalinity5. Farm Chemical Application6. Bacteria/Cryptosporidium

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

36 “ Screened Intake

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

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.

Discharge 2010

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

New Caisson

Farm Chemical Application

• Atrazine and Nitrogen• Nearly eliminated since RLWA improvements• Carbon caps on filters• Powder Activated Carbon

Syngenta Atrazine

Bacteria/Cryptosporidium

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

Questions???• mbraster@rrwa.net

• jbuckingham@rrwa.net

• (800) 233.8849

• www.rrwa.net

• www.rathbunlandwateralliance.blogspot.com