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Membrane Treatment Plant Increases Water Supply Reliability for
the City of Lodi
Richard Stratton. P.E.
HDR Engineering
Presentation Outline
Background
Project Goals and Objectives
Site Evaluation
Process Evaluation
Impacts on Existing Distribution
System
Design/Implementation Overview
BackgroundWater supply was groundwater only with
26 wells
San Joaquin County aquifer is in
overdraft condition
City began purchase of 6,000 AF/Y of
Mokelumne River water from Woodbridge
Irrigation District (WID) in 2003
Water has been banked with WID,
however water banking would have
expired in 2010 if no project to use water
started
Groundwater Level in Lodi Area has been Steadily
Dropping since the 1940s
Surface Water Treatment Facility Project Goals and Objectives
Evaluate alternative SWTF sites and treatment processes
and conduct fatal flaw analysis
Utilize surface water directly to reduce groundwater use
and eliminate overdraft condition
Complete project design and start construction in 2010
Once plant operation begins, take advantage of excess
plant capacity to utilize banked water
Alternative Sites Evaluated
Site A Selected
Selected SWTF Site Near River Fits Well in the Community
Mokelumne River Water QualityConstituent 3/4/10 3/17/10 3/31/10 4/14/10 4/26/10 Max Min Mean
Temperature, oC 11.2 13.3 14.3 12.9 16.7 16.7 11.2 13.7
pH, standard unit 7.8 7.7 8.5 8.4 8.1 8.5 7.7 8.1
Turbidity, NTU 3.2 1.6 1.6 2.2 1.9 3.2 1.6 2.1
Bicarbonate alkalinity, mg/L * 20 * 20 * 20 20 20
Carbonate alkalinity, mg/L * <2.5 * <2.5 * <2.5 <2.5 <2.5
Hydroxide alkalinity, mg/L * <2.5 * <2.5 * <2.5 <2.5 <2.5
Total alkalinity, mg/L * <2.5 * 16 * 16 <2.5 9
Hardness, mg/L * 16 * 16 * 16 16 16
Total organic carbon, mg/L * 1.6 * 1.8 * 1.8 1.6 1.7
Dissolved organic carbon, mg/L * 1.3 * 1.5 * 1.5 1.3 1.4
Colilert total coliform, MPN/100mL >1600 900 >1600 900 * >1600 900 1250
Colilert E. coli, MPN/100mL 300 17 170 50 * 300 50 134
Giardia, cysts/L 0.38 ND 0.05 0.42 0.55 0.55 0.05 0.35
Cryptosporidium, oocysts/liter 0.14 ND ND 0.05 ND 0.14 0.05 0.10
Color, units- * 5 * 5 * 5 5 5
Odor, TON * <1 * <1 * <1 <1 <1
Source: City of Lodi Public Works Department, 2010
Key: * = not sampled
mg/L = milligrams per liter
[ND = not detected
MPN/ 100mL = most probable number per 100 milliliters
NTU = nephelometric turbidity unit
TON = threshold odor number
Mokelumne River Water Shed Sanitary Survey
Excellent Quality with Low TDS and low
TOC concentrations
Fecal Coliform levels are slightly elevated
requiring 4-log Giardia removal
Cryptosporidium detected – LT2 sampling
ongoing
Turbidity is normally less than 10 NTU with
levels above 50 NTU possible during high
run-off events
Water Supply and Demand Considerations
The available supply is 6,000 AFY (5,000 AFY in the summer and 1,000 the winter)
Banked water must start to be used by 2012 or risk losing the water
Existing wells should be operated daily
Up to 13,000 AFY of WID may become available for future demands
Year Available
Supply*, AFY
Required Plant
Capacity, MGD
2010 6,000 8
2030 13,000 20
Water Supply and Required Treatment Capacity
* Does not include carryover banked water
Recommended Phase 1 Plant Capacity
10 mgd to allow for use of banked water
Treatment Process Evaluation
Conventional
Treatment
Water quality relies on chemicals
Older technology
Higher present worth (PW) cost
Membranes
Recommended
Membranes provide positive barrier
for reliable high quality water
New and improving technology
Easier operation and lower PW cost
Much less chemical use required
Smaller footprint
Membrane Evaluation Conclusions
City toured several membrane plants
Criteria: reliability, fiber breakage
history, operator comments
City selected Pall membranes
Required Steps to Implement Project
Prepare Detailed Design
Conduct Bidding and Contractor Selection
Construction and System Start-up
Develop Financing Plan
Prepare Initial Study and CEQA Documents
Conduct LT2 Source Water Sampling for Cryptosporidium
Prepare Watershed Sanitary Survey
10 mgd Plant Fits in a Compact Site
Facilities:
Raw Water Pump Station
-Raw Water Pipeline
-Flash mixer
-Sedimentation Basin
-Strainers (400 micron)
-Pall Membrane System (5
Skids)
-3 Mgal Concrete Clearwell
-High Lift Pump Station
--Backwash plate settler
-On-site Hypo Generation
-Soda Ash Silo and Feed System
-Treated Water Pipeline
Process Flow Schematic
New WID Fish Screen and Intake will Supplies Water to
the City
Craftsman StyleArchitecture Fits with Park setting and
Surrounding Neighborhoods
Pall Membrane System Achieves Giardia/Cryptosporidium LRV of 4.0
Membrane Feed Pumps
Pall 8-inch Quad Racks (2 mgd
capacity, each)
Membranes require low chemical use -
primarily for membrane cleaning
SWTF Incorporates Sustainable Design Features
On-site
hypochlorite
generation saves
the City $3 million
(O&M) costs over
20 years
Plate settler allows recycling of
backwash water increasing plant
efficiency to 99.8 %
Surface Water and Groundwater Blending
Considerations
Existing distribution system piping
has low levels of corrosion scales –
limited chlorination
Blending will be feasible with pH
adjustment and corrosion inhibitors
Public education and outreach is
recommended in advance of system
wide chlorination
Modifications to Existing Delivery System
Chlorination equipment added to all the well sites
Upgrades to the SCADA facilities for the SWTF and well sites
Construct 36-inch transmission main along North Mills Ave to Elm Street
Actual Cost vs. Original Project Budget
Actual cost - 13 percent
under original $42 million
budget
Labor Hour Estimate for Staffing a New WTP
Estimated O&M Costs after Optimization
Item Annual Quantity Unit Cost Annual Cost
Chlorine for Wells, lbs 34,000 $1.25 $42,500
On-site Generated Chlorine 1 $40,000 $40,000
Membrane Chemicals:
Caustic, lb 4,650 $0.25 $1,163
Citric Acid, lb 29,000 $0.60 $17,400
Sodium Bisulfite, lb 15,812 $1.20 $18,974
Soda Ash, lb 292,234 $0.27 $78,903
Alum, lb 23,000 $0.17 $3,910
Power, kWh/yr
Raw Water Pumping 176,096 $0.11 $19,371
Membrane Pumping 431,435 $0.11 $47,458
Membrane EFM/CIP/Compressor 472,000 $0.11 $51,920
High Service Pumping 978,310 $0.11 $107,614
Labor, hrs/yr (Post Commissioning Baseline) 12,480 $67.75 $845,520
Materials 1 $65,000 $65,000
Solids Disposal to Sewer 1 $51,300 $51,300
Subtotal $1,391,033
Total Estimated Annual O&M Cost $1,391,033
Implementation Schedule
Task Start Date Completion Date
Receive Bids September 16, 2010
Award Construction Contract October 29, 2010
Construction Period December 15, 2010 October 15, 2012
Testing and Start-up October 15, 2012 November 15, 2012
Project finished on
schedule
Membrane Treatment Plant Increases Water Supply Reliability for
the City of Lodi
Richard Stratton. P.E.
HDR Engineering