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