Big Valley Rancheria Corrosion Control Study

Big Valley Rancheria Corrosion Control Study Funded by: EPA Region 9 RCAC is a subcontractor to the Horsley Witten Group, Inc.

Big Valley Rancheria Corrosion Control Study Big Valley Rancheria Sarah Ryan, Environmental Director RCAC Lee Schegg, RDS Environmental Engineer

Rural Community Assistance Partnership, Inc. Western Rural Community Assistance Corporation 916/447-2854 www.rcac.org Midwest Assistance Program 952/758-4334 www.map-inc.org Southern Community Resource Group 479/443-2700 www.crg.org Northeast RCAP Solutions 800/488-1969 www.rcapsolutions.org Great Lakes WSOS Community Action Commission 800/775-9767 www.glrcap.org Southeast Rural Community Assistance Project 866/928-3731 www.southeastrcap.org 800/321-7227 www.rcap.org

Funding The Study recounted in this presentation was funded by a Environmental Protection Agency, Region 9 Drinking Water Tribal Set-Aside Grant

Big Valley Rancheria Corrosion Control Study Background Water System Lead and Copper Compliance Variations

Location Big Valley Rancheria - Lake County, CA Tribe: Big Valley Band of Pomo Indians of the Big Valley Rancheria Serves: 38 Residences Konocti Vista Casino Motel Tribal Offices RV Park Plans: 200 more residences

Big Valley Rancheria Location Clear Lake Lake County

Big Valley Band of Pomo Indians Lakeport Clear Lake

Big Valley Rancheria Site Residences Casino Residences Well Water Treatment Plant

Original Treatment Features (2003) Potassium Permanganate Injector Ozone and Air Preparation System Iron Filters Ultraviolet Light System Multimedia Filters Carbon Filters Water Softener Chlorine Injection System External Potable Water Holding Tank Grundfos Boosterpaq Pumps Diesel Fire Pump

Existing Water System Schematic

Well Pump Station

Water Treatment Plant Building

Green Sand Filters in WTP Building

GAC Filters and Zeolite Softeners

Hypochlorite and Phosphate Tanks and Pumps

Treated Water Storage Tank

Distribution Pumps and Diesel Driven Fire Pump

Lead and Copper Rule Compliance History 2003 Plant went on line 2006 Sarah Ryan produced a report as result of lead and copper exceedances

Lead and Copper Rule Testing (20 Residences in Fall 2016) Copper Lead Test Site mg/l Rank Percentile ug/l Rank Percentile 500 YH 9.50 1-100 1 560 YH 1.2 4-58 2 90 th 570 YH 1.1 5-41 3 580 YH 1.3 2 90 th 31 4 3105 RF ND 19-28 5 600 YH 0.12 10 50 th 12 6 3125 RF 0.19 7-5.5 10 50 th The rest of the sites are under LCR action limit.

Water Quality Conditions High corrosivity Constant High iron Variable High manganese Constant High hardness (Motel softens water) High CO 2 Constant High turbidity Periodic High color Periodic Taste Okay Odor Okay

Big Valley Rancheria Corrosion Control Study Creative Process Professional Search EPA Collaboration Contract

Creative Process Professional Search EPA Collaboration Contract Negotiation

Contract EPA Funded Investigation: $25,000 Corrosion control and quality improvement testing: Kennedy/Jenks Consultants Corrosivity Evaluation Corrosion Control Options Pilot Testing Comparison of alternatives Cost: Capital and Operations Report and Recommendations

Big Valley Rancheria Corrosion Control Study Bench Scale Testing Theory Methods Used Results

Corrosion Control Theory Water Quality Parameter Testing Plotting Milliequivalents of Cations and Anions at Various Points in System

Corrosion Control Options ph Elevation: Air stripping Caustic addition Inhibitors: Phosphate: Previously used 3 mg/l, 30% ortho, and 70% poly blend and other phosphate blends and dosages. Not sufficiently effective. Silicate: Too much silica with 80 mg/l in well water can inhibit iron and manganese removal at ph above 7.2

CO 2 Air Stripping Alternatives Type: Packed tower Diffused air Subsurface aeration Spray aeration Vacuum pressure stripping Condition: Iron fouling: Double Pumping Apparent best Storage tank: High iron settling High energy Iron fouling

Anticipated Testing Phosphate Blend Dosage Testing Caustic Additions

Actual Testing 18 Liter Capacity Tub 3.4 Liters per Minute small aquarium aerator

Test Instruments and Lab Equipment

Initial Pour Testing Raw Water 250 ml Beakers phtester 1

CO 2 Stripping Preliminary Testing Initial pour testing back and forth in 250 ml beakers. Pours ph 0 6.9 5 7.2 30 8.3

Diffused Air Stripper Testing 18-Liter Tubs Photo at ph 6.94 Photo at ph 7.56

Diffused Air Stripper Testing 18-Liter Tubs Photo at ph 7.87 Photo at ph 8.27

Diffused Air Stripper Testing 18-Liter Tubs Aeration: 3.4 liters/minute Blower ph: Initial 6.8 15 minutes: 7.4 30 minutes: 7.85 45 minutes: 8.0 60 minutes: 8.3

Caustic Additions to Elevate ph

Bench Scale Testing Linear polarization test method by Metal Samples Company (portable) MS 1500L data logger with 3-inch length x ¼-inch copper probes. 3-inch x ⅜-inch lead probes Electrochemical method of potential displacement ΔE/ΔI polarization resistance that provides a real-time measurement of uniform and/or pitting corrosion.

Bench Scale Tub Aeration and ph Testing Each Week of 4- Week Test Period

Copper and Lead Linear Polarization Probes

Lead and Copper LPR Probes in Tub Cover

Bench Scale LPR Test Assembly Tested Each Week after Aeration CO 2 Stripping

Linear Polarization Testing Each Week of CO 2 Stripped, ph Elevated Phosphate Inhibited Water

Corrosion Rate Readout in mils/year

Copper Probes Before and After

Lead Probes Before and After

Bench Scale Corrosivity Testing Week ph Existing Water Copper Corrosion Rate mils/yr ph CO 2 Stripped Water Copper Corrosion MPY Lead Rate MPY Corrosion Reduction Percent 0 6.9-8.2 - - - 1 6.9 8.02 8.2 2.2 2.1-2 6.7 0.69 8.3 0.18 0.16 73 3 7.5 0.88 8.0 0.23 0.14 74 4 7.5 0.76 8.0 0.14 0.11 83

Big Valley Rancheria Corrosion Control Study Solutions Interim Long Range

Recommended Interim Water Treatment Improvements Interim: Diffused air stripper: 60-minute detention at 130 GPM Improved iron and manganese removal: Pyrolusite media to three existing and conversion of two GAC and four Zeolite filters to pyrolusite to reduce loading rate by two-thirds.

Recommended Interim Water Treatment Improvements - Continued Interim: Storage tank: Sludge removal and cathodic protection Cost: $200,000 interim treatment and $300,000 wastewater treatment plant separation by containment wall ($100,000 CO 2 stripping and $100,000 improved iron removal)

Existing Water System Schematic

Interim Treatment Schematic

Long Range Treatment (for wastewater separation) CO 2 Stripping Water Softening by Lime with Iron- Manganese Precipitation Filtration Chlorination Phosphate Inhibitor Cost: $3 million

Long-Term Treatment with CO 2 Stripping

Long-Term Treatment Schematic

Faucet Replacement Alternatives An option to provide water treatment for LCR compliance possibly is removal of brass faucets. Six faucets were removed and found three high lead and copper and three from low lead and copper test residences. All faucets found to be different types of chrome-plated faucets. Copper plumbing removal from eight residences. Cost was about $15,000 each = $120,000 and more expensive than corrosion control treatment

Big Valley Rancheria Corrosion Control Study Lessons Learned Find the right engineer/scientist Collaboration between parties involved Obvious treatment methods aren t Importance of monitoring

Find The Right Engineer/Scientist Right level of expertise Civil Engineers Sanitary Engineers Firms with Engineers and Scientists Right level of experience

Collaboration Between Parties Involved Communication Needs Technology/Abilities Funding Education Process (Patience)

Obvious Treatment Methods Aren t The inclusion of treatment processes and their sequence and interaction must be based on: Sound and complete raw water data Knowledge of the water chemistry Water treatment design, construction and maintenance

Importance of monitoring Timely chemical adjustments and their effects on the water served through a specific monitoring program is extremely important.

Big Valley Rancheria Corrosion Control Study For Further Information Lee Schegg lschegg@rcac.org 916-704-8134

Big Valley Rancheria Corrosion Control Study Questions?