GWRS FE Engineers Report Complete - Orange County Water

GWRS Final Expansion Engineer’s Report‐ Sept 2016

ii

TableofContents

Table of Contents .......................................................................................................................................... ii

Chapter 1 – Introduction ........................................................................................................................... 1

1.1 Background ..................................................................................................................................... 1

1.2 Project Description and Objective .................................................................................................. 1

Chapter 2 – Source Water for the Final Expansion Project ...................................................................... 3

2.1 Source Water ‐ Orange County Sanitation District ......................................................................... 3

Chapter 3 – Groundwater Replenishment System Final Expansion Description .................................... 17

3.1 AWTF Process Expansion .............................................................................................................. 17

3.2 OCSD Improvements ..................................................................................................................... 22

Chapter 4 – GWRS Final Expansion Product Water ................................................................................ 26

4.1 Seawater Barrier (Talbert Barrier) ................................................................................................ 26

4.2 Forebay Recharge Operations ...................................................................................................... 27

4.3 Mid‐Basin Injection ....................................................................................................................... 29

4.4 Water Quality Monitoring ............................................................................................................. 30

Chapter 5 – Financial Analysis ................................................................................................................. 31

5.1 Capital Cost of Project ................................................................................................................... 31

5.2 Annual Operation and Maintenance Costs ................................................................................... 33

5.3 Potential Sources of Financing ...................................................................................................... 33

5.4 Projected Unit Cost of GWRS FE Project Water ............................................................................ 33

Chapter 6 – Project Implementation ...................................................................................................... 38

6.1 CEQA and NEPA Requirements ..................................................................................................... 38

6.2 Institutional Agreements .............................................................................................................. 38

6.3 Regulatory Approvals .................................................................................................................... 38

6.4 Sequencing of Project Activities and Schedule ............................................................................. 38

6.5 Financial Impact to OCWD ............................................................................................................ 39

6.6 Recommendation .......................................................................................................................... 40

Appendix ....................................................................................................................................................... A


1

Chapter1–IntroductionThe Orange County Water District (OCWD) began operating the Groundwater Replenishment

System (GWRS), located in Fountain Valley, California, in 2008. The 2008 GWRS facility

consisted of a 70 million gallon per day (MGD) advanced water treatment facility (AWTF), a 13

mile GWRS pipeline, and an expansion of OCWD’s Talbert Seawater Barrier Injection Wells. The

original AWTF and pipeline projects were designed and constructed for an ultimate treatment

and conveyance capacity of 130 MGD. The original GWRS design intent was to expand the

GWRS facility in two phases – an initial expansion of an additional 30 MGD of treatment

capacity and a final expansion of another 30 MGD of treatment capacity. The GWRS Initial

Expansion Project was completed in June 2015 and allows the AWTF to produce 100 MGD of

purified water for groundwater injection and recharge. The GWRS Final Expansion project will

include facilities required to upgrade the AWTF to produce 130 MGD of purified water as well

as facilities required to convey the source water for GWRS treatment. This Engineer’s Report

evaluates this final expansion of the GWRS facility.

1.1BackgroundThe OCWD manages the groundwater basin in northern and central Orange County, California

by protecting, monitoring, and recharging the groundwater basin. Northern and central Orange

County cities and water agencies (Producers) pump approximately 75% of their water demand

from the groundwater basin to supply potable water to homes and businesses. The source

water for OCWD’s groundwater recharge currently comes from Santa Ana River base flows and

storm flows, purified recycled water from GWRS, incidental recharge, and imported water from

Metropolitan Water District (MWD).

The 100 MGD AWTF as part of GWRS treats OCSD secondary effluent to drinking water

standards and uses the purified water for both injection and percolation, through injection

wells and recharge basins, as source water to replenish the groundwater basin’s drinking water

supplies. Figure 1 shows the GWRS existing facilities.

1.2ProjectDescriptionandObjectiveThe existing AWTF has the capacity to receive 134 MGD of secondary effluent from the Orange

County Sanitation District (OCSD) wastewater treatment plant and produce 100 MGD of

purified water for recharge. The AWTF treats the secondary effluent with microfiltration,

reverse osmosis and ultraviolet light to produce purified water for groundwater recharge. In

order to increase the capacity of GWRS for the Final Expansion Project, the AWTF will require

additional microfiltration cells, reverse osmosis units, ultraviolet vessels, and associated

equipment in order to produce an additional 30 MGD of purified water. These improvements

are referred to as the AWTF improvements. In addition to the AWTF improvements, for the

GWRS Final Expansion Project, additional source water from OCSD’s wastewater treatment

Figure 1 – Existing OCWD Facilities


2

plants is required. With the treatment process efficiencies, approximately 40 MGD of secondary

effluent is required from OCSD to produce the additional 30 MGD of purified water through

GWRS. This additional 40 MGD of secondary effluent will be pumped to the GWRS facility from

OCSD’s Treatment Plant No. 2 located in Huntington Beach.

The source water conveyance and AWTF treatment improvements will allow the GWRS facility

to produce the total planned 130 MGD GWRS Final Expansion production capacity. The

additional 30 MGD of purified water will be used as a new source of replenishment water for

the Orange County groundwater basin.

1.2.1SecondaryEffluentReuseStudy,SP‐173The Secondary Effluent Reuse Study, (SP‐173) is a jointly funded study by OCWD and OCSD to

evaluate the feasibility of recycling the majority of OCSD’s secondary effluent for GWRS Final

Expansion Project. CDM Smith and Brown & Caldwell completed the study in July 2016. The SP‐

173 study evaluated numerous alternatives for obtaining the required secondary effluent for

GWRS, to segregating non‐reclaimable flows at OCSD, to conveying the secondary effluent

flows to GWRS, and to maximize the secondary effluent flow to GWRS. The study incorporated

an alternatives analysis approach using ‘Criteria Decision Plus’ to evaluate numerous

alternatives in order to recommend the optimal project implementation plan for the GWRS

Final Expansion. The recommended results from this study are summarized in this Engineer’s

Report.


3

Chapter2–SourceWaterfortheFinalExpansionProjectThe OCSD operates two wastewater treatment plants that collect all of the wastewater from

north and central Orange County for treatment. The OCWD & OCSD have worked together for

over 40 years with OCSD providing secondary effluent free of charge to OCWD for further

treatment for groundwater replenishment. This section describes the considerations for

receiving an additional 40 MGD of secondary effluent at source water for the GWRS Final

Expansion Project.

2.1SourceWater‐OrangeCountySanitationDistrictThe OCSD owns and operates two treatment plants, Reclamation Plant No. 1 (Plant No. 1) in

Fountain Valley and Treatment Plant No. 2 (Plant No. 2) in Huntington Beach. Currently to

operate the GWRS AWTF to produce 100 MGD of purified water, OCWD receives all its

secondary effluent from OCSD’s Reclamation Plant No. 1. Figure 2 shows the locations of the

GWRS facility, and OCSD’s two treatment plants.

In order for OCWD to reach the final capacity influent water requirement, OCWD will need

effluent water from both of OCSD’s treatment plants.


4

Figure 2 – GWRS Final Expansion Project Area Map

2.1.1ReclamationPlantNo.1–FountainValleyThe OCSD owns and operates the Reclamation Plant No. 1, which is located in Fountain Valley.

Reclamation Plant No. 1 (Plant No. 1) has a maximum capacity to treat approximately 180 MGD

of raw wastewater to secondary effluent. All the raw wastewater is sent through the OCSD’s

headworks and primary treatment settling basins. The effluent from the primary settling basins

is distributed to three various secondary treatment processes. The three processes are as

follows:

(1) Activated Sludge Plant 1 (AS1): Original activated sludge system optimized for BOD

removal and converted with the addition of anoxic cells to a nitrification and partial

denitrification (NDN) process. The process removes over 90% of tractable organic


5

material (BOD) and undissolved solids, and has removal of ammonia, partial removal of

nitrate nitrogen, resulting in high quality secondary effluent for GWRS recycling.

(2) Activated Sludge Plant 2 (AS2): Newer activated sludge system designed for nitrogen

removal while providing equivalent removals of trace organics as AS1, producing high

quality secondary effluent for GWRS recycling.

(3) Trickling Filter (TF): Trickling filter system which removes similar amounts of tractable

organic material and suspended material as AS1, however the TF process is less effective

than the AS systems at removing suspended solids, ammonia and organics. The TF

process provides a lesser quality effluent for GWRS recycling, although it does provide

the ammonia necessary to form the necessary combined chlorine (chloramine) residual

upon the addition of sodium hypochlorite for efficient AWTF operations.

2.1.2TreatmentPlantNo.2–HuntingtonBeachThe OCSD also owns and operates the Treatment Plant No. 2 (Plant No. 2), which is located in

Huntington Beach. Plant No. 2 has the capacity to treat 80 MGD of raw wastewater to

secondary effluent. The wastewater comes into Plant No. 2 through the headworks and primary

settling basins. The effluent from the primary settling basins is distributed to one of two

secondary treatment processes. The two treatment processes are as follows:

(1) Oxygen Activated Sludge (OAS): Uses pure oxygen instead of air to provide metabolic O2

for a conventional activated sludge system for BOD removals. The effluent produced is

of lesser quality as compared to the Plant No. 1 AS1 and AS2 facilities NDN process,

featuring greater suspended solids, ammonia, and organics.

(2) Trickling Filter Solids Contact (TFSC): Similar to P1 TF except with an additional biological

treatment step that increases removals of BOD over conventional TF systems and

provides some additional removal of organics and suspended solids, but overall

produces lesser quality than the Plant No. 1 AS1 and AS2 NDN processes, especially for

ammonia.

Approximately 60% of the Plant No. 2 primary treated effluent is sent to the TFSC facility for

secondary treatment. The remaining 40% is sent to the OAS facility for secondary treatment.

The TFSC plant receives peak wastewater flows that come into Plant No.2 and is therefore

operated dynamically to manage the high and low flows.

2.1.3ProjectedSecondaryEffluentFlowsThe proposed source water for the GWRS Final Expansion Project is secondary effluent from

OCSD’s two wastewater treatment facilities. The current combined influent into OCSD’s two

wastewater treatment facilities is approximately 182 MGD. For the final expansion of GWRS,

OCWD will require a total of approximately 174 MGD of secondary effluent to produce 130


6

MGD of purified water and produce 4 MGD of reclaimed water through OCWD’s Green Acres

Project (GAP) facility. This 174 MGD of recommended secondary effluent assumes that the

AWTF microfiltration (MF) treatment process continues to operate at 90% efficiency, where

10% of the influent water returns to OCSD as Backwash Waste (BWW), and that the Reverse

Osmosis (RO) treatment process operates at an 85% recovery rate, where 15% of the influent

water returns to OCSD as RO concentrate for disposal in OCSD’s ocean outfall. Figure 3 shows

the projected secondary effluent recommended to produce the 130 MGD of GWRS product

water with the associated treatment process wastes.

Figure 3 – Projected Secondary Effluent and Process Waste Flows for the GWRS Final

Expansion Project

Therefore, in order to receive 174 MGD of secondary effluent from OCSD, the flows from

OCSD’s Plant No. 2 will need to be considered.

2.1.3.1OCSDInfluentFlowsIn recent years there has been a steady decline in wastewater influent flows to OCSD. Figure 4

shows the average daily influent flows over the past 20 years.


7

Figure 4 – OCSD Total Wastewater Inflow for both Plant No. 1 & 2

The 2007‐2009 economic recession, the ongoing drought and the water restriction mandates by

the State of California are possible reasons for the decline in wastewater inflows in these recent

years. Although, OCSD’s treatment facilities have the ability to treat up to 260 MGD on average

during non‐peak flow operations, in the most recent months the average daily influent has

declined to 182 MGD. This 182 MGD average inflow is still more than the 174 MGD required for

GWRS to produce 130 MGD of purified water, however a number of other factors must be

considered to fully evaluate the availability of secondary effluent for GWRS.

2.1.3.1.1TreatmentPlantNo.2FlowsandSARIOCSD Plant No. 2 receives domestic wastewater from the coastal and central Orange County

trunk lines. In addition to the local wastewater, Plant No. 2 also receives water from the Inland

Empire Brine Line. The Inland Empire Brine Line, which is also known as the Santa Ana Regional

Interceptor (SARI) pipeline, accepts desalter brine wastes from utilities and higher strength/sale

waste from industries in the Upper Santa Ana Watershed. This water contains brine,

concentrated waste streams, and effluent from the Stringfellow Hazardous Waste site in

Riverside County and is currently not allowed to be used as source water for recycling through

the AWTF by the Regional Water Quality Control Board permit to operate GWRS. The average

SARI line flows into Plant No. 2 are 31 MGD. Approximately 30% of this flow is the brines,

concentrated waste streams, and Stringfellow flows. The remaining 70% of the flows are local

wastewater collected along the SARI pipeline alignment in Orange County.

175

195

215

235

255

275

295

OCSD Influent Flow, MGD

OCSD Total Influent Flow


8

Since these SARI flows are currently not allowed to be recycled through GWRS, they will have to

be segregated and treated separately from the other domestic wastewater trunk sewer flows

that flow into Plant No. 2, thereby allowing the remaining Plant No. 2 flows to be recycled. The

improvements required to separately treat the SARI flows are discussed in more detail in

Section 3.2.3 of this report.

Since the SARI line contains approximately 70% of local Orange County wastewater in addition

to the SAWPA area flows, the SP‐173 study evaluated the feasibility of diverting these Orange

County raw wastewater flows out of the SARI line, so that the diverted flows could add

additional secondary effluent for recycling through GWRS.

Per the SP‐173 study, there are three simple diversion projects that will be implemented by

OCSD in the near future. These are referred to as SARI‐1, SARI‐2, and SARI‐3 in the report.

Implementing these three projects will divert an estimated 8 MGD of domestic wastewater out

of the SARI trunkline and into adjacent Plant No. 1 trunklines that can be recycled by GWRS.

Table 1 details the three OCSD diversion projects that are planned to be completed in 2017.

Table 1 – OCSD SARI Diversion Projects

Project ID Description Predicted Domestic WW Diverted Out of SARI

(MGD)

SARI‐1 Yorba Linda Pump Station Diversions into Newhope‐Placentia Trunkline

2.4

SARI‐2 Miller/Miraloma Diversions into Atwood Sub Trunk Sewer

1.9

SARI‐3 Gate Diversions into Atwood East Trunk Sewer

3.7

TOTAL 8

With these diversions, 23 MGD will remain in the SARI Trunkline, approximately half of which is

domestic wastewater and half of which is brine flows. These SARI flows will have to be

segregated and treated separately at OCSD’s Plant No. 2.

2.1.3.1.2TreatmentPlantNo.2FlowsandWasteStreamsDuring normal plant operations, OCSD produces on average 6 MGD of waste streams from their

solids handling processes. These waste streams are made up of centrate/filtrate from

thickening and dewatering processes, DAFT underflow, and OCWD RO Cleaning Wastes. This 6

MGD of waste streams is the average flow for OCSD’s Plant No. 1 & Plant No. 2 combined. It is

preferred to not recycle these flows through GWRS due to possible NDMA precursors in the


9

polymers used and concentrations of ammonia and organics they contain. Therefore, for these

reasons, the 6 MGD of OCSD waste streams will also be segregated from secondary effluent for

GWRS. These waste streams will be rerouted through the same segregated treatment train that

is designated for the SARI flows discussed in the previous section. Therefore the proposed

segregated flows for separate treatment at OCSD Plant No. 2 include the 23 MGD of SARI

trunkline flows and 6 MGD of waste stream flows for a total of 29 MGD which will not be

recycled through GWRS.

2.1.3.1.3OCWDandOCSDSecondaryEffluentUsesOCWD owns and operates a reclaimed water treatment facility referred to as the Green Acres

Project (GAP) on the GWRS site. OCSD’s secondary effluent is also used for source water for the

GAP treatment system. On average, 4 MGD of OCSD secondary effluent is used to feed the GAP

reclaimed water system. The GAP treatment process consists of a flocculation/mixing tank and

dual‐media filters followed by a chlorine contact basin for disinfection to produce non‐potable

tertiary treated water for reclaimed water endusers. Currently OCWD serves approximately 100

end users (including irrigation for parks, golf courses, schools) with GAP water. Discussions on

the future of this system are on‐going, however for the purpose of this report it will be

assumed that approximately 4 MGD of OCSD secondary effluent will go towards GAP.

In addition to GAP, OCSD uses approximately 2 MGD of secondary effluent internally on

average throughout OCSD’s facilities as dilution water for various treatment processes. This 2

MGD of dilution water will be referred to as Plant Water and is the average plant water usage

for both OCSD’s Plant No. 1 & 2. Since the GAP and OCSD Plant Water have steady demands for

secondary effluent, these flows cannot be used for GWRS.

2.1.3.1.4AdditionalSecondaryEffluentFlowsforGWRSFEAn additional source of treated wastewater used for recycling through GWRS is the backwash

waste water produced from the Microfiltration (MF) Treatment Process at the AWTF. The MF

process requires a 2‐3 minute backwash flush of the MF modules every 22 minutes. This

backwash water is MF filtered water combined with particles that have built up on the outside

of the MF modules. This MF backwash waste water is suitable for recycling and is sent to

OCSD’s Plant No. 1 for treatment, and then returned to GWRS for recycling. The average

backwash waste flows depend on how much water is being treated through the MF cells and

the frequency of backwashes. Based on the current flow predictions for the GWRS Final

Expansion Project, it was assumed that the MF backwash waste returning to GWRS would be

approximately 16 MGD.

Another source of wastewater for OCSD is the treatment of 0.6 MGD of MF cleaning wastes.

After every 21 days of run time for each MF cell, the cell is cleaned through filling the cell with

cleaning solutions (citric acid and sodium hydroxide) and recirculating these cleaning solutions


10

through the membranes. These cleaning wastes are currently piped to go to OCSD’s waste

streams and are therefore not recycled. However, these cleaning wastes can be safely recycled

through GWRS with minimal piping improvements to allow these flows to comingle with the MF

BWW flows. These flows would then be treated through OCSD’s treatment processes at Plant

No. 1 and counted as additional secondary effluent for GWRS.

Another source of additional secondary effluent for the GWRS Final Expansion Project is the

Extraction Wells for the North Basin Clean‐up Project. OCWD will begin construction in

December 2016 on the Extraction Well No. 1 (EW‐1) Project. The extraction well will be

installed within the City of Placentia and the discharges from this extraction well will be routed

into an OCSD sewer trunkline which feeds Plant No. 1. The project is scheduled to be complete

in 2017 and it is estimated to discharge approximately 1.4 MGD to Plant No. 1 for treatment

and eventual recycling through GWRS.

In addition to the process waste streams mentioned above, there are potential urban runoff

flows within Orange County that currently flow into storm drains/channels that could be

diverted to OCSD for treatment. The OCSD Board of Directors adopted a resolution in 2000 to

allow 10 MGD of urban runoff to be treated at OCSD free of charge to any parties interested.

This incentive helps cities and agencies with urban runoff water quality issues develop new

projects that would divert the urban runoff into OCSD’s sewer trunklines for treatment. The

cities/agencies responsible for the runoff would fund and manage these projects. Recently, the

OCWD Board of Directors approved helping fund the Santa Ana Delhi Channel Diversion Project

with City of Costa Mesa, Newport Beach, Santa Ana, and County of Orange which will divert

approximately 1.4 MGD of urban runoff to OCSD Plant No. 1. This project is currently in design

and is scheduled to be complete in 2017.

Table 2 below shows the predicted flows to GWRS considering the segregated SARI, segregated

waste stream flows, OCSD Plant Water Flows, GAP flows, and MF backwash waste (BWW) flows

and new listed influent flows.


11

Table 2 – Predicted Available OCSD Secondary Effluent for GWRS

Water Type Average Flows (MGD)

OCSD Wastewater Influent 182

Segregated SARI Trunkline Flows ‐31

Segregated OCSD Waste Stream Flows ‐6

GAP Flows ‐4

OCSD Plant Water Flows ‐2

MF Backwash Waste Flows 16

OCSD SARI Diversion Projects 8

MF Cleaning Waste Flows 0.6

EW‐1 Flows 1.4

Urban Runoff Delhi Channel Flows 1.4

TOTAL 166.4

The predicted secondary effluent of 166 MGD is 7 MGD less than the optimal 174 MGD of

secondary effluent to produce 130 MGD of purified water through GWRS and 4 MGD of

reclaimed water through GAP. However, the total 166 MGD reflected in Table 2 is an average

predicted daily flow to OCSD. In OCSD’s current inflow are peak and low flows throughout the

day that can range between 20‐30 MGD in each direction. Therefore during peak flows, the

production of 130 MGD of purified water with the GWRS Final Expansion can still be met.

Also, with an average secondary effluent inflow of 166 MGD to the GWRS facility, OCWD will

still be able to maintain a reliable annual yearly production average of 25,000 acre‐feet per year

(AFY). The annual water production target is currently based on a 92% on‐line factor, however

the GWRS facility has been operating at a more consistent 97% on‐line factor in recent years.

With these considerations, the average 166 MGD of secondary effluent available for GWRS will

still allow the annual production of 25,000 AFY to be met with an on‐line factor of 90%. This

annual average production target will be compared with the annual costs for the GWRS Final

Expansion project in the financial section of this report. It is with these considerations that

OCWD recommends the GWRS Final Expansion Project despite lower than optimal average

influent wastewater flows.

However, if wastewater inflows for OCSD continue to decrease, there are additional outside

sources of wastewater flows that can produce new influent for OCSD and provide water for

GWRS. These potential projects are summarized in the section below.


12

2.1.3.1.5PotentialFutureSecondaryEffluentFlowsforGWRSFEThe SP‐173 Study analyzed all projects that would be required to divert the entire domestic

wastewater flows out of the SARI trunkline. However, the majority of these additional diversion

projects included the requirement for new sewer lift stations within Orange County, which add

significant operational and maintenance costs for these diversions. These diversions will not be

further considered at this time. However there are four more diversion projects that would not

require sewer lift stations and could be implemented if proven cost effective.

The four additional potential domestic wastewater diversion projects are referred to as SARI‐4,

SARI‐5.1, SARI‐5.3, and SARI‐5.7 in SP‐173. Summarized descriptions of these projects are

included in Table 3 below.

Table 3 – Potential OCWD Diversion Projects

Project ID Description Predicted Domestic WW Diverted Out of SARI

(MGD)

SAR‐4 Two New MHs & 200‐feet of 15‐inch Pipe Diversions into Taft Branch & Olive Sub

Trunkline

1.5

SARI‐5.1 2,800‐feet of Pipe Diversions from Orange to Atwood West

2.9

SARI‐5.3 11,000‐feet of Pipe Diversion from Anaheim to Olive Trunkline

1.6

SARI‐5.7 300‐feet of Pipe from Brea to Atwood West 1.4

TOTAL 7.4

OCSD’s Treatment Plant No. 2 receives the SARI line flows in addition to domestic wastewater

from trunk lines of OCSD’s sewer system. As mentioned in Section 2.1.2, the continuous flow

out of the advanced secondary treatment train at Treatment Plant No. 2 is approximately 55

MGD. The flow from this process could be pumped back to OCWD’s AWPF to make up the total

of 173 MGD of secondary effluent required for the source water for the final expansion.

There are additional urban runoff projects that may add more influent to OCSD’s Plant No. 1.

The Peters Canyon Wash Groundwater Disposal and Reuse Pipeline Project is designed to

capture groundwater dewatering or seepage related discharges from four locations in the lower

Peters Canyon Wash. The anticipated diversion flow to OCSD will could be approximately 1.8

MGD. Another potential urban runoff project is the Santa Ana‐Santa Fe Channel Diversion

Project. The City of Santa Ana is interested in diverting approximately 1 MGD of their Santa


13

Ana‐Santa Fe Channel and Lane Channel urban runoff flows to OCSD. If needed, OCWD would

pursue the schedule for implementing these projects.

The North Basin Groundwater Remediation Project is also recommending the installation of 4

more extraction wells. The four additional extraction well discharges could all be diverted into

an OCSD trunk sewer main for treatment at OCSD’s Plant No. 1. The flows from EW‐2 through

EW‐5 are projected to total 2.8 MGD on average. These discharges would be treated through

OCSD’s Plant No. 1 free of charge with the GWRS Final Expansion Project.

OCWD is also exploring the option of treating the GWRS RO concentrate flows and/or

recovering more water via the RO process. It is predicted that the RO concentrate discharge

flows will be approximately 23 MGD for the GWRS Final Expansion. These concentrate flows are

sent to the OCSD ocean outfall. There are pilot systems that OCWD will be evaluating that

would convey these concentrate flows through an additional specialized RO membrane stage

with approximately 50% recovery and therefore producing approximately 11 MGD of additional

GWRS product water. The cost to pilot such a system is included in the budget for the GWRS

Final Expansion Project in order to determine if such a system would be a cost effective tool to

boost water production.

2.1.3.2OCSDDiurnalFlowsRaw wastewater flows coming into Plant No. 1 and Plant No. 2 vary depending on the time of

day. Night time flows into OCSD can be as low as a total of 100 MGD into both plants.

Wastewater flows begin to lesson around midnight and gradually decrease until approximately

6am when wastewater influent flows begin to rise again. By 10am OCSD is typically back to

their peak influent flows.

In order to provide 133 MGD of secondary effluent continuously, for the GWRS Initial

Expansion, OCWD constructed Secondary Effluent Flow Equalization (SEFE) tanks to capture

peak flows from Plant No. 1. These peak flows are stored in the two 7.5 MG SEFE tanks and

pumped back to OCWD at night to supplement night‐time low flows of secondary effluent. With

this system, OCWD is able to capture the majority of the flows into OCSD’s Plant No.1 for

treatment at the Advanced Water Purification Facility.

In 2015, two 7.5 million gallon Secondary Effluent Flow Equalization steel tanks (SEFE) were

constructed on the AWTF site. These tanks store the secondary effluent peak flows from OCSD’s

Plant No. 1 during the day and at night this stored water is drained to supplement the low flows

from OCSD’s Plant No. 1.

For the GWRS Final Expansion Project, the feasibility of capturing the peak secondary effluent

flows and supplementing the low flows from OCSD’s Plant No. 2 is being studied. This separate

project may have the potential to enhance the overall water production through GWRS Final


14

Expansion. A final report analyzing the feasibility of this water production enhancement project

for OCSD’s Plant No. 2 will be completed in November of 2016 for further evaluation.

2.1.4ProjectedSecondaryEffluentWaterQualityThe AWTF of GWRS currently receives on average 25% secondary effluent from OCSD’s Plant

No. 1 Trickling Filter (TF) process. The remaining 75% of secondary effluent is from OCSD’s Plant

No. 1 Activated Sludge (AS) processes.

The AS process at OCSD’s Plant No. 1 (i.e. advanced secondary process) includes Nitrification‐

Denitrification (NDN) and it greatly reduces the concentration of ammonia in the secondary

effluent from OCSD. The NDN treatment process converts ammonia first into nitrite, then into

nitrate, and then a denitrifying bacteria converts some of the nitrate into nitrogen gas. The low

ammonia concentrations in the majority of the secondary effluent for GWRS allow the

microfiltration treatment process efficiencies to remain high.

The TF process at OCSD’s Plant No. 1 consists of a fixed bed of media over which a microbial

layer covers the outside of media. The primary effluent flows downward over the media for

treatment. This form of treatment does not remove ammonia. Currently OCWD is receiving

approximately 25% of OCSD’s secondary effluent from the trickling filter treatment process.

Since GWRS has been in operation, the more secondary effluent GWRS receives from the

trickling filter system, i.e. the more ammonia in the feed water, the quicker the microfiltration

membranes can foul, and require more frequent cleanings.

The ammonia in the feed water does also provide a benefit for GWRS. OCWD uses sodium

hypochlorite upstream of the microfiltration process to reduce biofouling of the microfiltration

and RO membranes. The small ammonia concentration from the TF process binds with the

hypochlorite to produce chloramines (combined chlorine), which act as a biocide to limit

fouling, but prevents the formation of free chlorine that can damage the membranes.

With the GWRS Final Expansion Project, secondary effluent from OCSD Plant No. 2 will be

required. In addition, the entire Plant no. 2 Oxygen Activated Sludge treatment train will be

isolated for SARI trunkflows and not available for GWRS source water. Therefore, the makeup

of the secondary effluent for the GWRS Final Expansion Project will be different with respect to

water quality. Table 4 below shows the predicted amount of secondary effluent from each

treatment process at OCSD that will be available for GWRS.

Table 4 estimates combined inflow of 182 MGD plus 3.4 MGD of new wastewater influent from

MF cleaning wastes, OCWD extraction wells, and Delhi Channel urban runoff flows.


15

Table 4 – Predicted OCSD Secondary Effluent Flows for GWRS

Water Treatment Process/Source Predicted OCSD/GWRS Flows (MGD)

Percent

Plant No. 1 ‐ Activated Sludge (AS1) Treatment 37 22%

Plant No. 1 ‐ Activated Sludge (AS2) Treatment 37 22%

Plant No. 1 ‐ Trickling Filter Treatment (TF) 20 12%

Plant No. 2 ‐ Oxygen Activated Sludge (OAS) ‐ SARI(1) 29 0%

Plant No. 2 ‐ Trickling Filter Solids Contact (TFSC) 60 35%

Recycled GWRS Flow ‐ MF Backwash Waste Flows 16 9%

TOTAL 170

(1) These flows will be treated separately and not recycled through GWRS

Table 4 shows that about 50% of the GWRS Final Expansion secondary effluent will come from

OCSD’s trickling filter treatment systems from both Plant No. 1 and 2. This will increase the

ammonia concentration in the feed water for GWRS.

In addition to the increase in ammonia, there are increases predicted in BOD, TOC, and TSS – all

of which also have the potential to foul the MF and RO membranes more quickly. There will

also be an 80% predicted increase in GWRS feedwater TDS (from the saltier effluent from Plant

No. 2 related to the infiltration of seawater into coastal sewer lines) which will increase feed

pressure for the RO process. Alkalinity, boron and chloride concentrations are also predicted to

increase. The higher concentrations of these constituents in the secondary effluent for GWRS

Final Expansion will have to be evaluated in more detail.

OCSD and OCWD are currently beginning a pilot study which will directly evaluate the effects of

this new TFSC source water from OCSD’s Plant No. 2 on the microfiltration membranes. OCWD

has set up a pilot MF unit at OCSD’s Plant No. 2 which will receive OCSD’s Plant No. 2 effluent.

The MF pilot unit will be evaluated for fouling and cleaning frequency. Pilot testing on 100%

trickling filter flows, including SARI flows, represents a worst case scenario for fouling potential

and actual fouling will likely be less. The unit will be run for approximately 6‐months and the

data from the study will be available for analysis prior to the design of this project to evaluate

whether additional water quality improvements should be recommended for optimal GWRS

operation.

2.1.4.1WaterQualityofSARIflowsThe current GWRS permit from the Regional Board (Order No. R8‐2004‐0002) has specified a

requirement for OCWD’s source water for GWRS. Specifically this order states: “Only secondary

treated wastewater from the OCSD Reclamation Plant No. 1 that does not include wastewater

flows from the Santa Ana River Inceptor (SARI) line shall be used as influent source water for


16

advanced tertiary treatment at the interim WF21 and GWRS”. The California Department of

Public Health also noted that SARI flows should not be utilized as source water for GWRS given

concerns related to unknown or potential risks from discharges to the SARI line. In order to

consider allowing OCWD to use the SARI line as source water for the final expansion, OCWD has

been asked to provide the following information:

1) Water quality characterization of the quantity and quality of discharges from the SARI.

2) A source control evaluation comparing the discharges of OCSD’s Plant 1 (GWRS Source

Water) and that of the SARI flows.

OCWD has conducted a separate water study to assist with the implementation of the GWRS

Final Expansion, which evaluated the water quality of the SARI trunkline, characterized the

number, type and flow of the individual IEBL/SARI dischargers in the SAWPA area, and reviewed

the SAWPA pre‐treatment (source control) program for IEBL/SARI. This study has concluded

that the SAWPA area IEBL/SARI brine flows have TDS concentrations in excess of 5,000 mg/L as

they enter Orange County. Recycling TDS water will add significant costs to operation GWRS.

The brine flows into the SARI line are expected to increase and become more concentrated

with increase in the use of groundwater and reclamation RO brine recovery processes. It has

also been noted that some irregular discharges from dump stations that flow into the SARI

trunkline are not adequately monitored for source water for water recycling. The SAWPA pre‐

treatment program for the IEBL has also been revamped in recent years due to serious

deficiencies uncovered by an OCSD audit. Additional SAWPA source control changes would be

recommended in addition to address potential risks associated with SARI recycling. It is for

these reasons that OCWD is currently not recommending to pursue actions that would allow

the SARI flows to be recycled through GWRS. In turn, this requires OCWD and OCSD to

recommend improvements that will treat the SARI flows separately and not allow these flows

to be conveyed to GWRS. These improvements are described in the next chapter.


17

Chapter3–GroundwaterReplenishmentSystemFinalExpansionDescriptionThe current GWR System is made up of an advanced water treatment facility, a pipeline,

injection wells and recharge basins. The original advanced water treatment facility (AWTF)

incorporated the final expansion water production capacity of 130 MGD into the design of the

process equipment spacing, pipeline sizes, number of pumps, and conveyance pipeline sizes.

These improvements are detailed as part of the AWTF Improvement Project section. In addition

to the added treatment capacity, a new pump station and pipeline at OCSD’s Plant No. 2 will

need to be constructed to convey additional source water to GWRS for treatment. With the

exclusion of Inland Empire Brine Line flows for treatment at GWRS, a headworks bypass facility

will also need to be constructed at OCSD Plant No. 2. These Plant No. 2 improvements

recommended for the GWRS Final Expansion Project are detailed as part of the OCSD

Improvements Section in this chapter.

3.1AWTFProcessExpansionThe following sections describe the proposed improvements to the Advanced Water Treatment

Facility in order to treat and produce 130 MGD of purified water.

3.1.1ScreeningFacilityThe Screening Facility currently has all that screens that are needed for the final expansion.

However current operations have shown that the screening facility storage tank may be

undersized or pipe elevations into the tank are too high. In order to make sure OCWD receives

the maximum flows, OCWD fills the screening facility tank in order to gravity flow the secondary

effluent into the 96‐inch Microfiltration Feed (MFF) pipe. There is a narrow water elevation that

allows water to flow into the MFF pipe before reaching too high of an elevation to overflow the

water to the ocean outfall (or SEJB 7). Therefore, when the screening facility storage reservoir

water elevation reaches the overflow elevation – secondary effluent is lost to the ocean. As

part of the final expansion, OCWD would like this scenario evaluated to ensure that all the

secondary effluent available is able to be captured and treated through the Advanced Water

Purification Facility.

3.1.2MicrofiltrationTo expand the microfiltration system to its final ultimate capacity, 12 additional microfiltration

cells will need to be added to the existing system. Train E will need to be expanded with 4

additional treatment cells. In addition, a new Train F will need to be constructed south of Train

E and on the west side of the microfiltration process area. Train F will be made up of 8 new

cells. The construction of the twelve new cells would occur by increasing the size of the

microfiltration building and basement, which houses most of the actual MF equipment. The MF

basement includes all piping, valves, pumps, instruments, and control panels. Figure 5 shows


18

the additional MF cells being added and the expanded building footprint.

Figure 5 – GWRS Final Expansion of Microfiltration Process

During the backwash process, in addition to water running through the membranes the

opposite direction to remove particulates that have accumulated on the membranes, the

membranes are agitated with a high volume of air blown over them. The high volume of air is

provided by the air blowers in the microfiltration basement. As part of the final expansion

project, one additional air blower will need to be installed (along with all the piping, valves,

appurtenances) that go along with feeding air to the new microfiltration cells.

One additional backwash waste pump will also be required to send water from the backwash

process to OCSD to be recycled as part of the final expansion. This waste is sent directly to

OCSD’s secondary treatment process.

3.1.3ReverseOsmosisWith exception of the equipment and piping, the Reverse Osmosis building is built out to full

capacity. Therefore for the final expansion, only two new trains will need to be installed. The

trains are made up of 3 units producing 5 MGD each, with 150 pressure vessels per unit. The


19

building also has room to house all the process equipment, piping, and electric cables for

operating the trains. The treatment train equipment includes pressure vessels, RO membranes,

RO feed pumps, and associated piping for each train. Figure 6 shows the location of the

additional RO equipment units that are being added as part of the GWRS Final Expansion

project.

Figure 6 – GWRS Final Expansion of Reverse Osmosis Process

One additional RO Flush Feed Pump will need to be installed as part of the Final Expansion

Project. This pump is a 50 hp horizontal end suction centrifugal pump which pumps RO

permeate at 1000 gpm at a rated head of 120 feet. This pump provides RO permeate water to

the RO membranes for flushing when a train is taken off‐line or for water when a train needs to

be cleaned.

3.1.4UltravioletDisinfectionThe advanced oxidation system currently part of the GWRS facility consists of hydrogen

peroxide being injected upstream of the Trojan Ultraviolet (UV) processes. The system currently

being used is the Trojan PHOX. In order to reach the final expansion capacity, three new trains


20

of the Trojan UV PHOX system will need to be installed. The piping leading up to the main

influent and effluent headers is already installed. In addition to three new trains, there will be

the three new electrical panels and PCS controllers. Figure 7 shows the layout of the existing

and proposed UV trains.

Figure 7 – GWRS Final Expansion of the UV System

In addition to the new trains, the UV canopy area is in need of a bridge crane system to allow

the UV units to be disassembled and moved out of the area for service or future installation.

3.1.5DecarbonationandLimeAs part of the GWRS Final Expansion Project, one additional decarbonation tower and

associated blower will need to be installed. The piping influent piping has already been

constructed. In order to connect the decarbonation tower to the existing influent piping, an

approximately 10‐foot 24‐inch diameter spool piece and valve will have to be installed. The

effluent will drain into the Decarbonated Water Tank directly underneath the towers. Figure 8

shows the location of the proposed decarbonator tower.


21

Figure 8 – GWRS Final Expansion of the Decarbonation System

The lime system is currently built out to incorporate final capacity flow rates and therefore no

additional work is required in this area.

3.1.6PumpStationsFor the Final Expansion Project, there will be one additional vertical diffusion vane pump

required to be installed in the existing Product Water Pump Station building. The pump shall be

rated at 20,140 gpm for 315 feet of head with a rated horsepower of 2,250 to match the four

existing pumps in the building. The 30‐inch discharge pipe and valve for the pump will be

connected to an existing 30‐inch pipe piece with a blind flange which connects to the common

discharge header for all the product water pumps.

For the Final Expansion two new Backwash Supply (BWS) pumps need to be installed. These

pumps are provided by Siemens and have existing 20‐inch discharge piping in the RO Transfer

Pump Station Building assembled and ready to be connected to the new pumps.


22

3.1.7ChemicalFor the Final Expansion Project, at least one additional 32,000 gallon steel sulfuric acid tank and

dosing pump will need to be installed. Currently there is room for two new sulfuric acid tanks

and pumps, however with developments in the use of new Threshold Inhibitors in the

treatment process, the sulfuric acid usage for the AWPF has decreased significantly. Therefore,

if the current operation of the AWTP is maintained, then only one sulfuric acid tank and pump

will be required to meet the production requirements for the GWRS Final Expansion Project.

During the design phase of the GWRS Final Expansion Project, the predicted sulfuric acid

chemical usage will be calculated taking into account the different source water quality.

3.1.8ElectricalEach process component that is being expanded as part of the final expansion project (as

mentioned in the above sections of this report), also has corresponding electrical work and

equipment (cables, panels, conduit) that needs to be installed.

3.2OCSDImprovementsAs mentioned in previous sections, OCWD requires 173 MGD of secondary effluent from OCSD

to produce 130 MGD of purified water for the GWRS Final Expansion Project. In order to convey

this volume of water to OCWD a few improvements on OCSD property will be required. An

effluent pump station, conveyance pipeline, and a separate headworks facility for SARI flows

will have to be constructed at OCSD’s Plant No. 2.

3.2.1OCSDP2EffluentPumpStationA secondary effluent pump station at OCSD’s Plant No. 2 is being proposed to send between 50

‐ 85 MGD of secondary effluent from Plant No. 2 to the GWRS facility. This pump station will be

referred to as the OCSD P2 Effluent Pump Station. Figure 9 shows the location of this pump

station.


23

Figure 9 – OCSD P2 Effluent Pump Station Location Map

The preliminary pump station layout is estimated to be approximately 47‐feet by 100‐feet with

a three duty and one standby pump configuration. The four (4) pumps will be 500 hp vertical

turbine pumps. The P2 Effluent Pump Station will take secondary effluent from the 120‐inch TF‐

SE pipeline and boost this flow into a new conveyance pipeline to GWRS.

3.2.2OCSDPipelineRehabilitationOCSD owns an existing unused 66‐inch gravity reinforced concrete pipeline (RCP) that connects

Plant No. 2 to Plant No. 1. This pipeline was constructed prior to 1965 and is no longer in

service. The pipeline alignment is 3.6 miles from Plant No. 2 to Plant No. 1. OCSD has surveyed

the interior of this pipeline and determined that the pipeline is no longer usable with exposed

rebar and deteriorating manholes. For the conveyance of secondary effluent from Plant No. 2

to the GWRS facility, OCSD will allow OCWD to use the 66‐inch existing pipeline and

construction easement. In order to convert this aging gravity RCP into a pressure pipeline to

convey the effluent pump station discharge, it is being proposed to slip‐line the existing

pipeline with a smaller diameter High‐Density Polyethylene (HDPE) pipe. The slip‐line repair

entails excavation of access pits along the pipeline alignment to expose and enter into the

existing pipeline. The new smaller diameter HDPE pipe will be pulled through the existing

pipeline between the access pits. The new pipeline will be connected on the south to the


24

Effluent Pump Station at OCSD’s Plant No. 2 and to the north to the existing 90‐inch OCSD

South East Junction Box No. 6 (SEJB6) influent pipeline. Figure 10 shows the pipeline alignment.

Figure 10 – P2 Secondary Effluent Conveyance Pipeline Alignment

3.2.3OCSDP2HeadworksSegregation/Modification In order to separate the SARI (brine) flows from comingling with domestic wastewater flows

into OCSD’s Plant No. 2, a separate headworks facility and bypass pipeline must be constructed.

The SARI brine flows will have a dedicated flowmeter vault and screening and grit basins. After

conveyance through the separate headworks, the SARI brine flows till be routed to the A‐side

clarifiers of OCSD’s Oxygen Activated Sludge treatment facility. The P2 OAS treatment facility

will be entirely dedicated to the treatment of the SARI trunkline brine flows. Figure 11 shows

the site plan for OCSD’s Plant No. 2 headworks segregation project.


25

Figure 11 – OCSD P2 Headworks Modification Project


26

Chapter4–GWRSFinalExpansionProductWaterThe 130 MGD purified water produced from the GWRS Final Expansion Project will be

recharged into the groundwater basin through a combination of existing and new facilities. The

two main sources for the GWRS product water are 1) the Talbert Seawater Barrier Injection

wells and 2) the GWRS Pipeline to recharge basins in the Anaheim area (i.e. the forebay area of

the groundwater basin).

4.1SeawaterBarrier(TalbertBarrier)OCWD owns and maintains the Talbert Seawater Barrier Injection Wells (Talbert Barrier).The

Talbert Barrier was constructed to minimize early evidence of seawater intrusion into the

groundwater basin. Currently, the Talbert Barrier contains 36 injection well sites, 32 of which

are joined by a common pipeline which run along Ellis Avenue in the City of Fountain Valley and

four along the Santa Ana River between Yorktown Ave. and Adams Ave. in Huntington Beach.

Figure 12 shows the locations of the injection well sites.

The annual Talbert Barrier capacity ranges from approximately 15 MGD to 36 MGD, with the

lower flow rates occurring in the winter season and higher flow rates in the summer. The

Talbert Barrier capacity is dependent on basin conditions, such as the degree of overdraft and

seasonal water level fluctuations. However, over the past 8 years of operation, the average

injection capacity for the Talbert Barrier has been 25 MGD (28,000 acre‐feet per year).


27

Figure 12 – Talbert Barrier Injection Wells

For the GWRS Final Expansion Project, to be more conservative in planning for necessary

recharge capacities, the average Talbert Barrier demand will be decreased 10% to 22 MGD.

During wet winter months, if the Talbert Barrier demands are temporarily below 22 MGD, the

AWTF can be operated at a lower production during those wet months if needed.

4.2ForebayRechargeOperationsOCWD operates several recharge facilities in north Orange County with the purpose of

percolating water via gravity into the ground. The majority of these recharge basins percolate

Santa Ana River water that is diverted into them. However, there are currently four recharge

basins that are dedicated for GWRS product water. These basins are Kraemer, Miller, Miraloma,

and La Palma Basins. Figure 1 shows the existing GWRS pipeline and their connection to the

GWRS recharge basins.

These basins are filled with GWRS product water as needed. Overtime, as the water percolates

into the ground, their fill rates decrease slowly until they require a cleaning. For cleaning

operations, the basins are fully drained, dried, and then scraped with heavy equipment to


28

remove the clogging layer. Including these operational and maintenance activities, average

recharge rates for these basins have been established and are summarized in Table 5 below.

Table 5 – Average Percolation Rates of Recharge Basins in Anaheim

Recharge Basin Average Percolation

Rate (MGD)

Kraemer Basin 45

Miller Basin 20

Miraloma Basin 26

La Palma Basin* 45

TOTAL 136 *The percolation rate for La Palma is estimated and not based on a yearly average. The La Palma basin is currently

being constructed and estimated to be completed in November 2016.

OCWD began using Kraemer and Miller Basins in 1988 and 1963, respectively. Kraemer Basin is

owned by OCWD. Miller Basin is owned by OC Flood Control District. During storm events, peak

storm flows overflow into Miller Basin and when this occurs percolation into the groundwater

basin stops. Miraloma Basin is located in Anaheim on E. Miraloma Ave. between N. Kraemer

Blvd. and N. Miller Street. Miraloma Basin is owned and operated solely by OCWD and began

operation in 2013. Miraloma Basin has received all of its influent water solely from the GWRS

AWTF from the GWRS Pipeline. With this fully advanced treated influent water, Miraloma Basin

has been able to percolate up to 50 cubic feet per second (CFS) or 32 MGD. However the

average percolation rate, including down time for cleanings, since its operation has been 26

MGD.

Geotechnical reports indicate that La Palma Basin should have a percolation rate similar to

Miraloma Basin because of their similar sand material. La Palma Basin is going to be slightly

larger than Miraloma Basin and therefore a percolation rate of 70 CFS or 45 MGD is predicted.

4.2.1PipelineCapacityConstruction for the GWRS Pipeline was completed in 2008. The pipeline conveys water from

the Advanced Water Purification Facility along the Santa Ana River for 13 miles to the

Kraemer/Miller, Miraloma and La Palma Recharge Basins in Anaheim. The GWRS pipeline is

concrete mortar lined and coated steel pipeline telescoping in diameter from 78‐inch, 72‐inch,

66‐inch and 60‐inch. During design of the pipeline, it was anticipated that there would be a

significant volume of water recharged in the mid‐basin area. With this assumption, the pipeline


29

and product water pump capacity to the recharge basins in Anaheim is limited to 85 MGD,

which is the maximum flow that can currently be pumped to the recharge basins.

4.2.2BurrisBoosterPumpStationThe current Product Water Pump Station located within the AWTF in Fountain Valley in

combination with the existing GWRS pipeline currently has a maximum capacity to convey 85

MGD to the recharge basins in Anaheim. Through a preliminary evaluation, using a hydraulic

model, incorporating a Booster Pump Station at Burris Basin would allow a total of 100 MGD of

product water to be pumped to the recharge basins in Anaheim. The existing Product Water

Pumps would operate in order to convey a minimum of 100 MGD to Burris Basin. The proposed

Burris Booster Pump Station would boost the remaining 100 MGD through the existing 60‐inch

GWRS pipeline to the recharge basins in Anaheim. The velocities in the existing 60‐inch pipeline

under the pumping scenario described above would be approximately 7.8 ft/sec which is within

a reasonable operating range. The proposed Burris Booster Pump Station configuration would

be five 600‐hp pumps total (4‐duty and 1‐standby) where each pump shall have a capacity to

pump 17,400 gpm to approximately 100‐feet of total dynamic head to the recharge basins. The

footprint of this pump station will be approximately 20‐feet by 40‐feet and will be located on

southern end of Burris Basin. In addition to the Burris Booster Pump Station, there is an existing

outlet on the GWRS pipeline that can be used to recharge GWRS product water into Burris

Basin. As needed, during wet winters, up to 7 MGD can be discharged into Burris through this

outlet. This Burris Booster Pump Station and Outlet Project will be evaluated under a separate

Engineer’s Report, however construction of this facility is required to recharge the GWRS Final

Expansion Product Water.

4.3Mid‐BasinInjectionIn addition to sending GWRS product water to the Seawater Barrier Injection Wells and the

recharge basins in Anaheim, the intention during the design of GWRS was to also send GWRS

product water to injection wells located in the mid‐area of the OC groundwater basin.

Historically, this mid‐area of the groundwater basin (mid‐basin) has had the lowest

groundwater levels comparatively throughout the basin. Therefore, in 2015, OCWD put into

operation the first Mid‐Basin Demonstration Injection Well. The Mid Basin Demonstration

Injection Well capacity was originally estimated to be 2,080 gallons per minute (gpm) or

approximately 3 MGD. However, to date the Mid Basin Demonstration Injection Well has been

operating at an average flow of 1,050 gpm or 1.5 MGD. OCWD is attributing this under

performance to potential issues that occurred during construction of the well. However, with

increased backwashing frequencies, OCWD staff have been able to raise the injection capacity

of this well. OCWD is proceeding forward with the construction for an additional 4 injection

wells in the mid basin area. These 4 wells are referred to as the Centennial Park Injection Wells


30

Project. To more appropriately reflect the performance of the demonstration mid‐basin

injection well – the capacity of these injection wells is predicted to be 6.5 MGD.

With all of the above mentioned facilities, the total 130 MGD of product water from the GWRS

Final Expansion will be able to be recharged. Table 6 below lists the facilities proposed to

recharge product water from GWRS Final Expansion Project. Since the Talbert Barrier Injection

wells have variable demands that depend on the season, the proposed recharge facilities will

also have variable demands corresponding with the Talbert Barrier. Table 6 lists the proposed

recharge facilities and the range in demand for each.

Table 6 – Summary of Average GWRS Recharge Basin Capacities

Recharge Facility

Capacity Range (MGD)

Talbert Seawater Barrier Injection Wells 15 ‐ 35

Mid‐Basin Injection Wells 8 ‐ 0

Burris Basin Outlet 7‐ 0

Burris Booster Pump Station to Recharge Basins 100 ‐ 95

Total 130

4.4WaterQualityMonitoringPer our permit from RWQCB, we are required to monitor for the following 400+ constituents on

either a quarterly or yearly basis. We are also required to prove that our facility is running

effectively. We do this by monitoring for the following indicators either daily or 24 hours a day,

7 days a week. Those indicators are TOC, pH, Turbidity, and EC. We don’t anticipate that using

the additional source water for the GWRS Final Expansion Project will require any additional

water quality monitoring beyond the current program.


31

Chapter5–FinancialAnalysisThe GWRS Final Expansion Projects costs will be estimated in this section. In addition to the

estimated capital cost, the operation and maintenance costs, unit costs, and comparison costs

to imported water will be evaluated for the GWRS Final Expansion Project.

5.1CapitalCostofProjectThe capital improvement projects required to enable the GWRS facility to produce 130 MGD of

product water include the Advanced Water Treatment Facility Improvements, the OCSD P2

Effluent Pump Station, the OCSD Pipeline Rehabilitation Project, and the OCSD Headworks

Segregation Project. The costs for these projects are represented in Table 7 below. The OCSD

Headworks Segregation Project will be managed by OCSD and costs reimbursed by OCWD. The

estimated capital costs for the three projects at OCSD’s Plant No. 2 (Effluent Pump Station,

Pipeline Rehabilitation, Headworks Segregation Projects) were incorporated from the

OCSD/OCWD joint study and include 35% contingency which is appropriate for the pre‐design

phase. The estimated capital cost for the AWTF Improvements was based on the bid results

from the GWRS Initial Expansion Project and therefore has a lower contingency due to having

recent accurate construction costs. The more detailed breakdown of the capital and

operational and maintenance costs for all these projects are included in the appendix of this

report.


32

Table 7 – GWRS Final Expansion Estimated Capital Costs

Description Cost

GWRS Final Expansion Projects

Advanced Water Treatment Facility Improvements

Pre‐Design $500,000

Design $12,000,000

Construction Services $10,000,000

Administration $6,000,000

Construction $94,000,000

Contingency $7,500,000

Total AWTF Project Cost $130,000,000

OCSD P2 Effluent Pump Station


Design $1,250,000





Total Pump Station Project Cost $17,700,000

OCSD Pipeline Rehabilitation Project


Design $1,750,000





Total Pipeline Project Cost $37,000,000

OCSD P2 Headworks Segregation Project


Design $3,000,000





Total Headworks Project Cost $44,700,000

TOTAL GWRS FINAL EXPANSION CAPITAL COST $229,400,000


33

In addition to the projects required to produce the 130 MGD of GWRS Final Expansion Project

water, there are projects that are required to be constructed to recharge the GWRS Final

Expansion Project water into the ground. These projects required for recharge include the Mid‐

Basin Demonstration Injection Well, Centennial Park Injection Wells, and Burris Booster Pump

Station Projects. The total project costs for these recharge projects are included in separate

Engineer’s Reports for each project.

5.2AnnualOperationandMaintenanceCostsIn addition to the normal operational costs, the final expansion project should see an increase

in the electricity usage due to a number of reasons. The pump pressure to push saltier water

through the reverse osmosis membranes will be increased and will therefore increase the

electricity usage accordingly. Also, in addition to operating the treatment facility – a new pump

station facility will be added to the equation. The OCSD pump station will most likely be

operated by OCSD and the operational costs paid by OCWD. For the purposes of this report the

cost of operating the new pump station is based on the costs of operating the SEFE pump

station. For the unit cost calculations, it is estimated that electricity usage will increase by 10%

per acre‐foot from current operations.

In addition to an increase in electricity costs, there is also a predicted increase in chemical

usage for more frequent cleaning requirements. With approximately 50% of the secondary

effluent for GWRS coming from trickling filter processes at OCSD, this increases the organics,

suspended solids, and ammonia concentrations in the secondary effluent. The higher organic,

suspended solids and ammonia concentrations in the influent for GWRS will affect the fouling

rate of the MF process, which could lead to reduced recovery due to increased cleaning

requirements. For the unit cost calculations, it is estimated that the chemical usage costs will

increase by 8% per acre‐foot from current operations.

5.3PotentialSourcesofFinancingOne potential source of financing this project is the Sate Revolving Fund (SRF) Loan Program.

Currently the state has a program of 30‐year loans at a 1.7% interest rate. This is being offered

on a first‐come, first‐serve basis and staff will be applying for this program for the GWRS Final

Expansion Project. However, to be more conservative, the unit cost for the GWRS Final

Expansion project was calculated for two scenarios, 1) with the SRF Loan Program at 1.7%

interest for 30 years, and 2) with typical bonds issued by OCWD at 5% interest for 30 years.

5.4ProjectedUnitCostofGWRSFEProjectWaterThe unit cost of the GWRS Final Expansion water includes the capital costs along with the

operation and maintenance (O&M) costs divided by the amount of extra water produced. Table

8 summarizes the calculated unit cost for the GWRSFE Project. For the calculation of this


34

number for the GWRS Final Expansion Project, a couple of assumptions were made. They are

the following:

1) It is anticipated that the Total Dissolved Solids (TDS) concentration of the secondary

effluent for the final expansion is going to increase by approximately 20%. This would

correlate with an 10% total electricity cost increase to compensate for the additional

electricity required to ramp up the RO feed pumps for the higher salinity water.

Likewise the increase in ammonia concentrations in the secondary effluent will most

likely increase the amount of chemical cleanings required to prevent fouling of the MF

membranes. This correlates with a 8% total chemical usage cost increase for GWRS Final

Expansion.

2) OCSD will continue to provide secondary effluent for GWRS free of charge as per the

original agreement and assist OCWD in efforts to treat free of charge additional

secondary effluent for recycling through GWRS.

3) An increase of 1 additional I&E technician and 1 additional maintenance full time

employee.

4) The GWRS Final Expansion Project is based on a maximum capacity to produce 130 MGD

of purified water. However, there are variable influent flow rates, plant facility planned

outages for maintenance, power service agreement outages, and construction outages

that must be factored into the amount of water that can be reliably produced within

one year. For this project, it is assumed that with a 92% plant on‐line factor, 25,000 AFY

can be reliably produced by GWRS Final Expansion. This is the production value used to

calculate the unit cost for this project.

5) The annual payment of the capital costs are calculated using both a 30‐year loan at a

1.7% interest rate if SRF Loan Program for GWRSFE is approved and a 30‐year loan at a

5% interest if the SRF Loan is not received.

6) There will be no MWD LRP subsidy available.

7) The R&R Debt service is the amount OCWD will budget for Repairs and Refurbishment

(R&R) of the treatment facility. This R&R value is the predicted annual cost of

replacement or refurbishment of equipment installed as part of this project. For this

analysis, the R&R value is half of the construction cost divided by the life of the

project/equipment. For this project, thirty years was assumed for the life of the

equipment.


35

Table 8 – GWRS Final Expansion Project Unit Cost

Item Costat1.7% Costat5%AnnualPaymentonCapitalCost $9,725,000 $14,780,000

O&MCosts $8,925,000 $8,925,000

R&RCosts $1,980,000 $1,980,000

TotalAnnualProjectCosts $20,630,000 $25,685,000

WaterProduced(AFY) 25000 25,000

UnitCost($/AF) $825 $1,027

Based on the assumptions listed above, the unit cost for the GWRS Final Expansion Project is

between $825/AF to $1,027/AF. OCWD policy established in April 2009 calls for comparing the

cost of new local water supply projects against the MWD treated full service rate. To be more

conservative, the higher unit cost of $1,027/AF for the GWRS Final Expansion Project based on

a 30‐year loan at 5% interest will be used to compare to MWD imported water rates.

On January 1, 2017, the cost of treated full service MWD water will increase from $942/AF to

$979/AF. There is a ‘readiness to serve’ charge that adds approximately an additional $65/AF

to the total cost of MWD water. This will bring the total treated full service MWD imported

water costs to $1,044/AF.

The GWRSFE local water supply project is groundwater replenishment water with a unit cost of

$1,027/AF. Since this product water is pumped into the ground – to accurately compare the

GWRSFE unit cost with the MWD treated full service rate – an estimated variable cost to pump

water out of the ground must be added to the GWRSFE Project costs. This variable cost to

pump the water out of the ground is received from a survey of Producers within the OCWD

service area and is currently estimated to be $97/AF. Figure 13 below shows the comparison of

the GWRSFE unit costs to the MWD treated full service water with all the applicable

adjustments.


36

Figure 13 – Comparison of GWRSFE Unit Costs to MWD Treated Full Service Unit Costs

With this comparison, the estimated GWRSFE unit cost is slightly more than the MWD Treated

Full Service Unit Cost. MWD Treated Full Service Unit Costs are predicted to increase by 4.5%

annually for the foreseeable future. The GWRSFE unit costs will increase on average with

inflation for only the operation, maintenance and electricity costs. The GWRSFE annual debt

service cost will be fixed. Therefore, although the GWRSFE Project unit costs are currently more

than MWD imported water rates, in the near future with the predicted increases in MWD

treated water rates, the GWRSFE Project unit costs should be less than imported rates. Figure

14 compares the predicted increases in GWRSFE Project unit costs versus MWD imported water

costs for the next 15 years.

$0

$100

$200

$300

$400

$500

$600

$700

$800

$900

$1,000

$1,100

$1,200

GWRS FE Project Cost MWD Treated Cost

Cost of Water ($/A

F)

TOTAL ‐ $1,044/AF

MWD Treated ‐ $979/AFGWRS FE Cost ‐ $1,027/AF

Pumping Cost ‐ $97/AF

TOTAL ‐ $1,124/AF

Readiness to Serve ‐ $65/AF


37

Figure 14 – Projected Increases to GWRSFE Unit Costs and MWD Treated Unit Costs

Figure 14 is compares the base unit rates for both the MWD treated full service water and the

GWRSFE Project unit costs without the readiness to serve and pumping costs included. Also,

two different inflation rates (1% and 2%) are compared for the GWRS FE Project unit costs

based on the future potential Consumer Price Index (CPI).

$0

$200

$400

$600

$800

$1,000

$1,200

$1,400

$1,600

$1,800

$2,0002016

2017

2018

2019

2020

2021

2022

2023

2024

2025

2026

2027

2028

2029

2030

Unit Cost ($/A

F)

MWD Treated Full ServiceWater

GWRS FE w/ CPI ‐ 1%

GWRS FE w/ CPI ‐ 2%


38

Chapter6–ProjectImplementationTo complete the GWRS Final Expansion Projects, CEQA will need to be completed, an

agreement between OCSD & OCWD will need to be completed, and any necessary regulatory

compliance issues addressed.

6.1CEQAandNEPARequirementsThe CEQA process for the GWRS Final Expansion Project will involve issuing an addendum to the

original Groundwater Replenishment System EIR. This addendum will address all the processes

that are being expanded as well as the new facilities at OCSD’s Plant no. 2. If this project is

financed by the State Revolving Fund Loan Program, the NEPA process will also need to be

completed.

6.2InstitutionalAgreementsOCWD and OCSD are currently working on an amendment to a joint agreement between the

two agencies which defines each agencies responsibilities for the GWRS Final Expansion Project.

In general it defines the project costs, land leases, and operational responsibilities for each

agency as part of all the joint OCWD and OCSD GWRS Projects.

6.3RegulatoryApprovalsGWRS is currently permitted by the Regional Water Quality Control Board (RWQCB) and

Division of Drinking Water (DDW). The RWQCB/DDW permit contains input and regulations

from California Department of Public Health (CDPH) as well. The DDW was formerly a part of

CDPH as a department/branch of the State Water Resources Control Board (SWRCB). The

current RWQCB/DDW permit will need to be amended to allow for the GWRS FE or a new

permit will need to be developed; the latter may be required, given the changes in

RWQCB/DDW regulations since the original GWRS permit was adopted in 2004.

6.4SequencingofProjectActivitiesandScheduleThe four improvement projects that make up the GWRS Final Expansion Project, will need to be

closely coordinated with OCSD. The three projects proposed on OCSD’s Plant No. 2 will have to

tie‐in with OCSD’s utilities and therefore incorporate many OCSD standards in addition to

OCWD’s standards. Additional design coordination time between the two agencies are factored

into the proposed schedule. The schedule for the GWRS FE projects are attached in the

appendix of this report. The final completion date for these projects may depend on the

availability of the rehabilitated primary clarifiers on OCSD’s Plant No. 2. These clarifiers are

required for the segregated SARI flows. OCSD is planning on rehabilitating these clarifiers

through their P2‐92 capital improvement project. The P2‐92 Project is currently in design.

Therefore, design‐construction‐operation schedules for the GWRS Final Expansion Projects and


39

the OCSD P2‐92 Projects will have to be closely coordinated in an effort to begin operating

these proposed facilities without delays.

6.5FinancialImpacttoOCWDIncorporating the GWRS Final Expansion Project will allow OCWD to increase the amount of

AWTF water used for groundwater replenishment to manage the groundwater basin. Figure 15

compares the yearly typical water supplies with and without the GWRS Final Expansion Project

available for recharge. As shown in Figure 15, the OCWD service territory could reduce the

amount of imported water purchased with the additional GWRS Final Expansion product water.

The financial benefit to the OCWD service territory of purchasing less imported water would

begin approximately after year 2018 as previously shown in Figure 14. After 2018, the GWRSFE

unit costs should continue to be less than the predicted increase in MWD treated water rates.

Figure 15 – Average Yearly Recharge Water Sources with and without the GWRSFE Project

With the GWRS Final Expansion project implemented, the OCWD service territory would

purchase 25,000 AFY less MWD treated imported water. With the predicted average increase in

‐

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

500,000

Typical Supplies Typical Supplies withGWRS FE

Average

Yearly Recharge

(AFY)

Treated MWD

MWD Untreated/Carson IRP

Misc

Natural Incidental

SAR Storm

SAR Base Flow

GWRS


40

the cost of MWD imported water of 4.5% each year, the OCWD service territory would gain a

financial benefit from implementing the GWRSFE Project after year 2018.

6.6RecommendationIt is recommended to establish the GWRS Final Expansion Project detailed within this report as

a feasible and viable project for the Orange County Water District.


A

Appendix

AWTF Expansion Project

Description Cost

Pre‐Design

CEQA 500,000$

Design & Consulting Services

Design of Construction Documents 12,000,000$

Construction Management 8,000,000$

Construction Inspection Services & Administration Costs 2,000,000$

Construction

Mobilization 6,000,000$

Microfiltration Equipment (Evoqua) 21,000,000$

Microfiltration West Building Expansion (Incl. piping, electrical) 16,000,000$

Reverse Osmosis Membranes, Vessels, Pumps, Piping, Apprt. 12,500,000$

UV Equipment (Trojan) 7,000,000$

Sulfuric Acid Tank & Pumps 500,000$

Electrical Equipment 9,000,000$

Process Control Integration (KDC) 5,500,000$

GWRS Pump Additions 2,500,000$

Construction Escalation/General Requirements/Bonds/Insurance 14,000,000$

Total Construction Cost 94,000,000$

Engineering, Legal and Administration

Administration Labor 1,700,000$

RO Recovery Pilot Study 300,000$

Public Outreach 500,000$

Legal Services 1,200,000$

Survey Consultants 800,000$

Outside Consultants 1,500,000$

Contingency 7,500,000$

Total AWTF Expansion Project Capital Costs 130,000,000$

Annual Costs for AWTF Expansion Project Cost

Electricity $4,200,000

Chemicals $1,800,000

Labor (2 laborers @ $150,000/yr) $300,000

Plant Maintenance $1,000,000

Total Annual O&M $7,300,000

Total Annual R&R $1,500,000

A1

OCSD Effluent Pump Station Project

Description Cost

Pre‐Design

CEQA 50,000$



Construction Management 600,000$

Construction Inspection Services & Administration Costs 400,000$

Construction


Pump Station 7,700,000$

Connection Pipelines 150,000$



Administration Labor 200,000$


Outside Consultants 200,000$


Total Pump Station Project Capital Costs 17,700,000$

Annual Costs for PS Project Cost

Electricity $1,000,000

Chemicals $0

Labor $275,000

Plant Maintenance $200,000

Total Annual O&M $1,475,000

Total Annual R&R $180,000

A2

OCSD Pipeline Rehabilitation Project

Description Cost

Pre‐Design

CEQA 250,000$





Construction


Slip‐line Pipeline 14,600,000$

Connection Pipelines 4,800,000$





Legal Services 400,000$




Total Pipeline Project Capital Costs 37,000,000$

Annual Costs for Pipeline Project Cost

Electricity $0

Chemicals $0

Labor $0

Plant Maintenance $150,000

Total Annual O&M $150,000

Total Annual R&R $300,000

A3

OCSD Headworks Modification Project

Description Cost

Pre‐Design

CEQA 500,000$





Construction


Flowmeter & Vault for SARI 6,000,000$

Headworks Modifications 8,800,000$

New Plant Water PS 7,000,000$

New Sidestream PS 500,000$

Junction Box for A‐side clarifiers 2,000,000$

Pipelines 5,000,000$





Legal Services 300,000$




Total Headworks Project Capital Costs 44,700,000$

Annual Costs for Headworks Project Cost

Electricity $0

Chemicals $0

Labor $0

Plant Maintenance $0

Total Annual O&M $0

Total Annual R&R NA

A4

GWRS Final Expansion Schedule

Jan‐Apr May‐Aug Sep‐Dec Jan‐Apr May‐Aug Sep‐Dec Jan‐Apr May‐Aug Sep‐Dec Jan‐Apr May‐Aug Sep‐Dec Jan‐Apr May‐Aug Sep‐Dec Jan‐Apr May‐Aug Sep‐Dec Jan‐Apr May‐Aug Sep‐Dec Jan‐Apr May‐Aug Sep‐Dec

OCWD Advanced Water Treatment Facility Expansion

OCSD Plant No. 2 Effluent Pump Station

OCSD Pipeline Rehabilitation

OCSD Plant No. 2 Headworks Modification

OCSD P2‐98 Primary Treatment System Rehabilitation Project*

*This is a Captial Improvement Project for OCSD to rehabilitate the primary clarifiers intended for the segregated SARI flows as part of OCSD P2 Headworks Modification Project. Therefore the construction phase for this project will need to be coordinated with GWRS FE construction schedule to

ensure adequate primary clarifier capacity is available upon completion of the GWRS Final Expansion Projects.

CONSTRUCTIONBID

BID

BID

CONSTRUCTION

BID CONSTRUCTION

CEQA RFP DESIGN CONSTRUCTION

RFP DESIGN

CEQA RFP DESIGN

CEQA RFP DESIGN

2021 2022 2023

CEQA RFP DESIGN CONSTRUCTION

2020

BID

PROJECT2016 2017 2018 2019

A5