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
Background
Water 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
Utilize surface water directly to reduce groundwater use
and eliminate overdraft condition
Evaluate alternative SWTF sites and treatment processes
and conduct fatal flaw analysis
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 Quality
Constituent
Temperature,
oC
3/4/10
3/17/10
3/31/10
4/14/10
4/26/10
Max
Min
Mean
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
>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
Colilert total coliform, MPN/100mL
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
Water Supply and Required
Treatment Capacity
Year
Available
Supply*, AFY
Required Plant
Capacity, MGD
2010
6,000
8
2030
13,000
20
* 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 provide positive barrier
for reliable high quality water
 New and improving technology
Membranes
Recommended
 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
Develop Financing Plan
Prepare Initial Study and CEQA Documents
Conduct LT2 Source Water Sampling for Cryptosporidium
Prepare Watershed Sanitary Survey
Prepare Detailed Design
Conduct Bidding and Contractor Selection
Construction and System Start-up
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 Style
Architecture 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
Chlorine for Wells, lbs
Unit Cost
Annual Cost
34,000
$1.25
$42,500
1
$40,000
$40,000
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
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
12,480
$67.75
$845,520
1
$65,000
$65,000
1
$51,300
On-site Generated Chlorine
Membrane Chemicals:
Power, kWh/yr
Labor, hrs/yr (Post Commissioning Baseline)
Materials
Solids Disposal to Sewer
$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