Matt Leach, P.E. CH2M Mark Eppich, P.E. City of Columbus Division of Water S. Dean Ramsey, P.E. CH2M 1
Presentation Topics Project Background Project Team Unique Challenges and Opportunities Risk Assessment and Mitigation Factors That Cannot be Controlled Quality and Quantity Quantity Quality Current Project Status/Lessons Learned 2
3 PROJECT BACKGROUND
Columbus, OH Service Area 7.2 Billion Gal Parsons Ave. (groundwater) 15.9 Billion Gal Dublin Rd. Hap Cremean 25.6 Billion Gal Dublin Rd. Water Plant City of Columbus Hap Cremean Water Plant 48.7 billion gallons in 2015 83% surface water Service population 1.16 million Parsons Ave. Water Plant (groundwater) 4
Treatment Plant Site COUNTY ENGINEER TREATMENT PLANT (1907/1972) US 33 PUBLIC ACCESS ADMIN BLDG 5 POST OFFICE RAILROAD
Existing Treatment Process Scioto River Conventional Lime Softening Plant 65 MGD Capacity Rapid Mix Flocculator Turbidity Settling Rapid Mix Flocculator Softening Settling Re-carbonation Filters Clearwell POTASSIUM PERMANGANATE PAC R3 ALUM Turbidity Basins 1 & 2 SODIUM HYDROXIDE SODA ASH LIME Softening Basins 2 & 3 Recarbonation Basin 4 CO2 SODIUM HYPOCHLORITE FLUORIDE Dual Media Filters West East ZN ORTHO-PHOSPHATE Scioto River Residual R7 Residual R1 Residual R2 Residual R3 Residual R2 6
Plant Treatment Goals Total Hardness: 120 mg/l to 125 mg/l as CaCO3 Alkalinity: >35 mg/l as CaCO3 Total Organic Carbon (TOC): <2.0 mg/l Nitrate: < 10 mg/l as N Atrazine: <2.5 ppb (MCL= 3.0 ppb) Stage 2 DBP Compliance: Target 80% of Location Running Annual Average (LRAA) and Operational Evaluation Level Comply with all primary drinking water regulations Taste and Odor 7
New Treatment Processes & Upgrades to 80 MGD Biologically Active Carbon Filters New Recarbonation System Ozone Ion Exchange Residuals Handling, Electrical, Pump Station, and Miscellaneous Plant Upgrades 8
9 PROJECT TEAM
Project Team Plant Operations & Maintenance Tools to the Operations Staff Pre- Construction Use 10
11 UNIQUE CHALLENGES & OPPORTUNITIES
UNIQUE CHALLENGES & OPPORTUNITIES Three Plants in System All Three Scheduled for Renovation Same Period Dual Power Feed to Plant Both Thru Same Substation Significant New Users Added to One Circuit City Owns Power System Dublin Rd. Water Plant City of Columbus Hap Cremean Water Plant Parsons Ave. Water Plant (groundwater) Plant Maintains System Pressures Short Response Time 12
13 RISK ASSESSMENT AND MITIGATION
Risk Assessment & Mitigation Ongoing Process in All Phases of Work Condition Assessment Criticality of Each Piece of Equipment Consequences of Failure Phasing Regulatory and Schedule Impacts Pilot Testing Capability of Processes/Potential Modifications Design Details-Construction Restrictions & Sequencing 14
Risk Assessment & Mitigation CONTRACTOR ENTRANCE 940 Construction Contract Phasing IEB CONTRACT 4 OGB OCB RCB CO2 TEMPORARY PUBLIC/EMPLOYEE ENTRANCE 15 TWIN RIVERS DRIVE POND PARK PARKING 910 15
16 FACTORS THAT CANNOT BE CONTROLLED
FACTORS THAT CANNOT BE CONTROLLED KEY FACTORS System Demand Weather Raw Water Quality MITIGATION FACTORS Share Demand Between Plants Upstream Monitoring Provide Tools for Treatment Plant Personnel Prepared 17
18 MAINTAINING QUANTITY & QUALITY
Phasing Criteria Quality & Quantity Regulatory Compliance Personnel & Public Safety Risk Assessment Contractor Work Areas/Interference/Use of Site Coordination with Construction at Other WTP Schedule and Approvals 19
20 QUANTITY
QUANTITY Three Plants System Hydraulic Model Demand Projections Power Upgrades 21
QUANTITY Replacement of: Residuals Pump Station High Service Pumps Raw Water Pumps Electrical System 22
23 QUALITY
QUALITY Approved Capacity for Each Process (OEPA) Upstream Monitoring Pilot Testing Existing New Historical Plant Data 24
CONSTRUCTION HOUSEKEEPING Filters Enclosure Requirements Performance Enforcement Exterior Improvements Open Basins Inflow Equipment in Basins High Service Pumps Control Room & Lab Crane in basin or filter 25
FILTERS Pilot tested existing and proposed media Rate (2.0 gpm/ft 2 to 3.4 gpm/ft 2 ) Performance Filters Out of Service Housekeeping Testing and Backwash 26
27 FILTERS
CHEMICAL FEED SYSTEMS Virtually every system rehabilitated or replaced Condition Assessment Risk Assessment Min. Tanks in Service Coordinate w/ Suppliers Removal w/o damaging Adjacent Tanks 28
RECARBONATION SYSTEM Installed a new Secondary System Operations prior to Shutdown of Existing Rental Tank during Switchover TEMPORARY RECARB EXISTING RECARB 29 NEW RECARB 29
POLYMER Coagulant Aid & Filter Aid Polymers Bench scale screening Plant scale testing Regulatory Approval Pre-Construction System Left in Place 30
31 PROJECT STATUS & LESSONS LEARNED
LESSONS LEARNED Expect the Unexpected PAC Quality Nitrate Event Need to Sweat the Small Stuff Chemical Deliveries (24/7) Good Housekeeping Emphasize Criticality Early Communication Sequencing & Restrictions Continuous Improvement Know Your Plant DESIGN & CM TEAM CITY STAFF CONTRACTOR 32
PROJECT STATUS 2014 2015 2016 Av. TOC 2.82 2.11 1.57 MIB Geosmin % Removal 66 65.4 69.9 RAW 3.66 7.14 TAP <1.0 <1.0 DRWP THM (ug/l) 15-Jun 16-Jun % reduction AVG 54.9 33.2 39 33
PROJECT STATUS 2014 2015 2016 Av. TOC 2.82 2.11 1.57 % Removal 66 65.4 69.9 DRWP THM (ug/l) 15-Jun 16-Jun % reduction AVG 54.9 33.2 39 DRWP HAA (ug/l) 15-Jun 16-Jun % reduction AVG 33.7 24.9 26 34
35 Thank you!
36 Questions?
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Existing Treatment Plant Site Original Plant -- 1907 Existing Plant Constructed --mid 1970 s No option to obtain additional property Railroad Post Office Major Road plus Scioto River County Engineers Office and Abandoned Landfill Department of Public Utilities Office Complex 1980 s 39
Existing Treatment Plant Site Multi Purpose Site Treatment Plant DPU Administrative Offices Fleet Maintenance Facilities Support Facilities and Personnel Access Required at All Times Public Access and Parking Space for Future Treatment Requirements 40
TEMPORARY RECARB EXISTING RECARB 41 NEW RECARB 41