Demand Response Feasibility Study for the Sewage Treatment ...capacity flow of greater than 1...

Design & Engineering Services

Demand Response Feasibility Study for the Sewage Treatment Industry DR 08.03 Report

Prepared by:

Design & Engineering Services Customer Service Business Unit Southern California Edison

December 2008

Demand Response Feasibility Study for the Sewage Treatment Industry DR 08.03

Southern California Edison Design & Engineering Services December 2008

Acknowledgements

Southern California Edison’s Design & Engineering Services (D&ES) group is responsible for this project in collaboration with the Tariff & Program Services (T&PS) group. It was developed as part of Southern California Edison’s Demand Response, Emerging Markets and Technology program under internal project number DR 07.04. D&ES project manager Roger Sung conducted this technology evaluation with overall guidance and management from Carlos Haiad of D&ES and Jeremy Laundergan of T&PS. For more information on this project, contact [email protected].

Disclaimer

This report was prepared by Dr. Lawrence Y.C. Leong of Kennedy Jenks Consultants in Irvine, Californian for Southern California Edison (SCE) and funded by California utility customers under the auspices of the California Public Utilities Commission. Reproduction or distribution of the whole or any part of the contents of this document without the express written permission of SCE is prohibited. This work was performed with reasonable care and in accordance with professional standards. However, neither SCE nor any entity performing the work pursuant to SCE’s authority make any warranty or representation, expressed or implied, with regard to this report, the merchantability or fitness for a particular purpose of the results of the work, or any analyses, or conclusions contained in this report. The results reflected in the work are generally representative of operating conditions; however, the results in any other situation may vary depending upon particular operating conditions.

mailto:[email protected]


ABBREVIATIONS AND ACRONYMS Cal ISO California Independent System Operator CSD County Sanitation District IEUA Inland Empire Utility Agency kW Kilowatt kWh Kilowatt-hour MGD Million gallon per day MW Megawatt MWD Municipal Water District SCE Southern California Edison SD Sanitation District STP Sewage treatment plant TOU Time of Use

WD Water District WRF Water Reclamation Facility WWRF Wastewater Reclamation Facility WWTF Wastewater Treatment Facility WWTP Wastewater Treatment Plant

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FIGURES Figure 1. Z Distribution of 80 STP’s Normalize Annual MWh per

MGD and Design Flow in SCE’s Service Area and....................... 8 Figure 2. Example of Diurnal Flow for a Bedroom Community

Service Area with a 2.7 MGD Average Flow with Corresponding TOU Electrical Rates........................................18

Figure 3. Distribution of Potential Shedding of MW by Load Reduction Scenario..............................................................25

Figure 4. Distribution of STPs Estimated to be Available to Participate in a SCE Demand Response Program ......................29

TABLES Table 1 List of 80 STPs in SCE’s Service Area Ordered by

Maximum Available kW ......................................................... 9 Table 2. Profile of the Major STP Industry within SCE’s Service

Area ..................................................................................13 Table 3. Profile of the Median Major STPs within SCE’s Service

Area ..................................................................................13 Table 4. Descriptive Statistics of the Major STPs Grouped by kW

Categories..........................................................................14 Table 5. Profile of Agencies Contacted for Upper Management

Presentations......................................................................21 Table 6 Summary of Agency, County Location, and Staff that

Attended Upper Management Presentations ............................22 Table 7. Profile of Agencies that Participated in Upper

Management Presentations ...................................................24 Table 8. Description of STPs that were Site Visited ...............................26 Table 9. Summary of Potential Load by Category Identified from

Nine Site Visits that Could Potentially be Taken Off the Grid...................................................................................27

Table 10 Profile of 19 Facilities that are not Likely to Participate in a Demand Response Program ..................................................30

Table 11. List of Potential Agencies and Facilities that may Participate in a Voluntary Demand Response Program ..............31

Table 12. Summary of Demand Response Program Features to Encourage STP Participation..................................................33

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CONTENTS EXECUTIVE SUMMARY _______________________________________________ 1

Background...........................................................................1 Approach ..............................................................................1 Findings................................................................................2 Recommendations for Implementation ......................................3

INTRODUCTION ____________________________________________________ 4 Background...........................................................................4 Project objectives...................................................................4 Approach ..............................................................................5 Report Organization................................................................5

PROFILE OF THE MAJOR SEWAGE TREATMENT PLANTS WITHIN SCE’S SERVICE AREA_ 6 Data Sources.........................................................................6

SCE Excel Spreadsheet ......................................................6 Clean Watershed Needs Survey...........................................6 Merging Information ..........................................................6 kW and Annual kWh Data from Facilities...............................7 Estimating kW and Annual kWh for STPs with no SCE Data......7 Use of Median Values.........................................................7

Descriptive Statistics of the STPs with in SCE’s Service Area.......13 Profile of All STPs as a Group ............................................13 STPs Profile by kW Categories ...........................................14

APPLICABLE DEMAND RESPONSE SCENARIOS FOR THE SEWAGE TREATMENT INDUSTRY16 Scenario Constraint - Carbon Footprint....................................16 Emergency diesel back up generators .....................................16 Storage ..............................................................................17 Reduction in Aeration............................................................17

Flow equalization to Optimize the Aeration process ..............17 Adjusting Aeration to Match Diurnal Hydraulics ....................17

Fat, Oil, and Grease..............................................................19 Locking out non-24/7 Processes .............................................19 Becoming a Third Party Aggregator.........................................20

UPPER MANAGEMENT PRESENTATIONS AND SITE VISITS _____________________ 21 Initial Contact......................................................................21 Description of 10 Upper Management Presentation Agencies.......21

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Description of Upper Management Presentations.......................23 General Reactions to the Presentations....................................23 Results of Site Visits .............................................................24 Estimated Demand Response Participation by the Sewage Treatment Industry.........................................................................................28 Potential Participation by 43 STP, >500 kW..............................29

Not Available for Participation (21 STPs).............................29 Available for Participation (22 STPs)...................................30

Estimated MW Reduction During a Demand Response Event .......32 Likely STP Demand Response Program Elements ......................32

FINDINGS AND RECOMMENDATIONS FOR IMPLEMENTATION _________________ 34 Findings..............................................................................34 Recommendations for Implementation ....................................35

REFERENCES _____________________________________________________ 36

APPENDIX A_____________________________________________________ 37 Irvine Ranch Water District Upper Management Presentation......38 Irvine Ranch Water District Presentation Memo ........................53

Southern California Edison Page iv Design & Engineering Services December 2008


Southern California Edison Page 1 Design & Engineering Services December 2008

EXECUTIVE SUMMARY BACKGROUND The SCE Demand Response program provides utility customers with financial incentives in return for voluntarily reducing electricity usage during periods when power generation or delivery is restricted. There are two scenarios for customers within SCE’s service area to shed load off the grid (a demand response event). One is initiated by the California Independent System Operator (Cal ISO) and the other can be initiated by SCE due to local conditions or problems.

The benefits of the SCE demand response program is that it allows peak load growth, and avoids the regulatory, environmental, and the real cost escalation of new power plants.

This study examines the demand response potential for the major (EPA’s definition of a major STP was used for this study and is a facility with a dry weather design capacity flow of greater than 1 million gallons a day[MGD]) municipal sewage treatment plant (STP) industry within SCE’s service area. The demand response conditions for this study would occur during the peak summer energy demand periods (May 1 through October 31), Monday through Friday, and in the 3 PM to 5 PM time period.

APPROACH The goals of this study were the following:

Provide a snap shot of the energy profile of the major STP facilities within SCE’s service area;

Estimate the participation of the STP industry (number of major STPs and load likely to be shed) in a SCE demand response program; and

Identify likely features and/or barriers of a demand response program for this industry.

The approach of the study was to execute five tasks were developed to accomplish the objectives of the project. The five task were the following: (1) Develop and finalize a list of major STPs within SCE’s service area; (2) Identify and finalize the list of demand response scenarios applicable to the municipal wastewater treatment industry as a whole; (3) Provide presentations to ten upper management STP personnel describing the project and requesting permission to perform site visits; (4) Perform nine STP site visits to determine potential site specific demand response options for shedding load; and (5) Prepare a Final Report that extrapolated and documented the findings of Tasks 1, 2, 3 and 4 to the STP industry within SCE’s service area.


FINDINGS Below are the findings of this report:

There are 56 agencies that own 80 major STPs in SCE’s service area, nine of which own more that 2 STPs

The 80 STPs have a maximum load of 120 MW and used 407,000 MWh from 1 July 2007 to 30 June 2008

The total dry weather design flow is ~1,510 MGD with a current dry weather flow of ~1,080 MGD that serves a population of 9.9 million.

For the same kW category, there was a range from 10 to 100 fold in the design flow rates indicating a non-standard design and unit process approach for this industry (see Table 4).

The most likely scenario for a STP to participate in a demand response program is a facility with more than 500 kW and tertiary treatment.

Power associated with pumping has the highest potential for load reduction in response to a demand response event

Six out of the 80 STPs in SCE’s service territory currently participate in a third party demand response program.

It is estimated that 11 STPs (15 percent of the remaining 74 STPs) would participate in a SCE demand response program.

It is estimated that these 11 facilities would reduce load by 6.1 MW during a demand response event.

A demand response program that encourages STP participation should have the following elements:

♦ More SCE outreach in explaining the options and program incentives and benefits because most managers of STPs are not familiar with the term “demand response” or these SCE programs

♦ A higher $/kW ♦ Reduce or elimination of penalties or a longer phase in of the program

so the STP industry can make the appropriate adjustments ♦ A shorter two hour period to drop load, preferably in the 3 -5 PM range ♦ More SCE assistance in estimating cost savings for dropping load

under current or a future program designed for the STP industry



RECOMMENDATIONS FOR IMPLEMENTATION An outreach program to educate the STP industry would result in more STP

participation.

Develop a visitation program with a team approach consisting of members with expertise in STPs and the appropriate SCE account representatives that could develop the cost savings for the demand response scenarios. Three phases are recommended and described below.

♦ Phase 1. The focus of this phase would be to follow up with the STPs that participated in the site visits of this study and that showed an interest in participating in a SCE demand response program

♦ Phase 2. Prioritize the list of STPs that were not visited in this study and perform a presentation and site visit.

♦ Phase 3. Determine whether there are any opportunities with the 200-500 kW group of STPs to perform a presentation and site visit.



INTRODUCTION BACKGROUND The SCE Demand Response program is designed to reduce peak energy demand when California needs it most. Qualifying customers who can reduce power when statewide energy supplies are low can earn significant discounts, incentive payments, bill credits, and can help get the best return out of every energy dollar spent. Generally, the on peak energy demand is in the summer season as defined by SCE’s TOU-8 rate Schedule, i.e., the first Sunday in June to first Sunday in October and from noon to 6 PM time period.

There are two scenarios for customers within SCE’s service area to shed load off the grid (a demand response event). One is initiated by the California Independent System Operator (Cal ISO). The other can be initiated by SCE due to local conditions or problems.

The California ISO (Cal-ISO) is a not-for-profit public-benefit corporation charged with operating the majority of California’s high-voltage wholesale power grid. This organization is responsible for balancing the demand for electricity with an equal supply of megawatts. When they predict a 5 percent short fall in generation capacity as compared to predicted demand, the Cal-ISO issues a Stage 2 alert. In response to this alert the retail electricity providers initiate a demand response call which activates various residential, commercial, and industrial programs to shed load off the grid (a demand response event).

SCE also monitors the electrical grid within its service area. Due to local conditions or problems, SCE may issue an alert to activate demand response to shed load off the grid within its service area.

The benefits of the SCE demand response program is that it allows peak load growth, and avoids the regulatory, environmental, and the real cost escalation of new power plants.

PROJECT OBJECTIVES This study examines the demand response potential for the major (EPA’s definition of a major STP was used for this study and is a facility with a dry weather design capacity flow of greater than 1 million gallons a day[MGD]) municipal sewage treatment plant (STP) industry within SCE’s service area. The demand response conditions for this study would occur during the peak summer energy demand periods (May 1 through October 31), Monday through Friday, and in the 3 PM to 5 PM time period.

This report is a feasibility study with the following objectives.

1. Develop a snap shot of the major STPs within the SCE service area

2. Develop an estimate of the level of participation by major STPs in a SCE demand response program.



3. Identify current barriers, if any, that impede participation by the STP industry in SCE’s demand response program.

If the results of this feasibility study are attractive, there may be a follow-up demonstration phase to provide data that a STP can participate in a demand response program without affecting its primary missions and goals of their facility.

APPROACH The approach of the study was to execute five tasks were developed to accomplish the objectives of the project. The five task were the following: (1) Develop and finalize a list of major STPs within SCE’s service area; (2) Identify and finalize the list of demand response scenarios applicable to the municipal wastewater treatment industry as a whole; (3) Provide presentations to ten upper management STP personnel describing the project and requesting permission to perform site visits; (4) Perform nine STP site visits to determine potential site specific demand response options for shedding load; and (5) Prepare a Final Report that extrapolated and documented the findings of Tasks 1, 2, 3 and 4 to the STP industry within SCE’s service area.

REPORT ORGANIZATION Section 1 provides a project background and project objectives. Section 2 presents a snap shot of the existing major STPs within SCE service area. Section 3 summarizes the industry-wide scenarios that most STPs can implement for a demand response event. Section 4 summarizes the ten presentations that were made to upper management of the owners of the STPs. These presentations described the project and the major elements of SCE’s demand response program. During this meeting, requests were made to perform a site visit of their facilities. A summary of the nine site visits is also provided in this section. Section 5 presents a projection of the STP facilities that would most likely participate in SCE’s demand response program. Findings and recommendations are presented in Section 6.



PROFILE OF THE MAJOR SEWAGE TREATMENT PLANTS WITHIN SCE’S SERVICE AREA

DATA SOURCES There were three data sources for this project. One was an Excel spreadsheet from SCE’s BCD Technical Support. Another was an EPA database for publicly owned treatment works (POTWs) call the Clean Watershed Needs Survey. The third source was from selected agencies.

SCE EXCEL SPREADSHEET An Excel file from SCE’s BCD Tech Support - Analysis and Program Support unit was provided. It contained customer information with SIC code 4952 for the period July 1, 2007 to June 30, 2008 (fiscal year 07-08). The file contained the customer name, facility name, the maximum kW, and the annual kWh used fiscal year 07-08. There were 1,728 service accounts.

CLEAN WATERSHED NEEDS SURVEY EPA maintains a database called the Clean Watershed Needs Survey (CWNS). The Clean Water Act requires that EPA develop the capital needs of all the publicly owned treatment works (POTWs) every four years. A POTW is a STP that is owned by a state, municipality, or special district. It does not include federally, Indian nation owned, or investor owned facilities.

The most recent survey was completed in 2004 and was made available to the public in early 2008. The states are responsible for updating this database and this update was started in early 2002 and finalized in 2004. The list of POTWs in each of the counties served by SCE was down loaded from the CWNS. The following data was used from this database:

Facility Name

Authority Name

Present Flow (MGD)

Dry Weather Design Flow (MGD)

Population Served

MERGING INFORMATION The CWNS was then reduced to only include major POTWs. This list and associated data were then cross referenced for the counties within SCE’s service area with the SCE Excel data. No private, investor owned, federal, or Indian nation owned major STPs were identified in this process.

SCE representatives were sent this listing to confirm that a questionable STP was within SCE’s service area. In some cases the STP were within Pacific Gas or Electric’s or San Diego Gas and Electric’s service areas. Some were removed because they were separate, stand alone tertiary recycling facilities owned and



operated by a different agency. These facilities did not have primary, secondary or sludge treatment facilities make their energy profiles and options for demand response totally different than STPs with tertiary treatment facilities.

Table 1 identifies the 80 major STPs within SCE’s service area, 72 with SCE data for annual kWh for the period fiscal year 07-08 and the maximum available kW. The data sources for the remaining eight facilities are described below.

Currently, out of the 80 STPs, six already participate and two are having discussions with a third party demand response aggregator. These facilities are noted in the comment section of Table 1. No STP is currently participating in a SCE demand response program.

KW AND ANNUAL KWH DATA FROM FACILITIES For two treatment plants, the Los Angeles CSD San Jose treatment plant and the Elsinore Valley MWD Regional treatment plant, staff at these facilities provided the kW and annual kWh information. In the case of the Los Angeles CSD, the data were from 1 September 2007 to 30 September 2008. These two facilities are identified in the comment section of Table 1.

ESTIMATING KW AND ANNUAL KWH FOR STPS WITH NO SCE DATA Six STPs did not have these data in the SCE information provided so these values were estimated. The use of these estimated data would not significantly skew the descriptive statistical information presented below because of their small treatment capacity.

The design capacity of these treatment plants were all < 3.2 MGD. There were 4 to 7 treatment plants with SCE data from which the estimates were made. The estimate was determined by taking the median values for STPs with SCE data that was +/- 1 MGD of the design flow for the facilities that did not have SCE data. For example, if the flow rate was 3 MGD, then the median value for plants with a design flow of 2-4 MGD was used for the estimated annual kWh and kW. In Table 1 the facilities with estimated values are noted in the comment column.

USE OF MEDIAN VALUES Figure 1 is a “Z” distribution of these facilities by MGD which indicates that these facilities have a log-normal distribution. For a log normal distribution, the geometric mean or the median (the middle value) is the best measure of central tendency. Because it is simpler to determine, in all cases, the median values which were used for the descriptive statistics of central tendency.



1 5 10 20 30 40 50 60 70 80 90 95 99

R2 = 0.9322

R2 = 0.9331

1

10

100

1,000

10,000

Z distribution

Nor

mal

ized

Ann

ual E

lect

rical

Usa

ge

(MW

h/M

G)

0.1

1.0

10.0

100.0

1,000.0

Des

ign

Flow

(MG

D)

Annual KwH/MGD DESIGN FLOW (MGD) Expon. (Annual KwH/MGD) Expon. (DESIGN FLOW (MGD))

FIGURE 1. Z DISTRIBUTION OF 80 STP’S NORMALIZE ANNUAL MWH PER MGD AND DESIGN FLOW IN SCE’S SERVICE AREA AND




TABLE 1 LIST OF 80 STPS IN SCE’S SERVICE AREA ORDERED BY MAXIMUM AVAILABLE KW

FACILITY AGENCY COUNTY

PRESENT

FLOW

(MGD)

DESIGN

FLOW

(MGD) POP

SERVED ANNUAL

KWH MAX KW COMMENT

Earlimart WWTF Earlimart PUD Tulare 0.8 1.2 4,733 131,745 32 Farmersville WWTF Farmersville, City of Tulare 1 1.3 8,737 202,342 33 Rosamond WWTF Rosamond

Community Service District Kern 1.1 1.3 16,337 345,834 52

California Inst for Men WWTF

California Dept Corrections

San Bernardino 0.8 1.3 6,313 413,080 71 kWh and kW estimated

Silver Lakes WWTF San Bernardino County, Spec. Dists Dept

San Bernardino 0.4 1.2 110 413,080 71 kWh and kW estimated

Santa Barbara WWTF Santa Barbara, City of Santa Barbara 8.8 11 93,000 112,612 71

Bishop WWTF Bishop, City of Inyo 0.9 1.5 6,561 319,032 73 June Lake WWTF June Lake PUD Mono 1 2,828 220,640 80 Avalon WWRF Avalon, City of Los Angeles 0.6 1.3 3,127 165,420 89 Fillmore WWTF Fillmore, City of Ventura 0.9 1.3 12,497 413,080 93 Corona WWTP #3 Corona, City of Riverside 1 x 413,080 112 kWh and kW estimated Indian Hills WWTF Jurupa Community

Service District Riverside 0.2 1.0 3,097 318,593 112 MARB WWTF Western MWD Riverside 0.3 1 5,700 413,080 112 Tehachapi WWTF Tehachapi, City of Kern 0.5 1.3 5,601 596,083 116 Exeter WWTF Exeter, City of Tulare 1 1.1 7,069 774,084 119 CSD Camarillo Water Reclamation Plant

Camarillo Sanitation District Ventura 4 61,576 497,640 149

Lindsay WWTF Lindsay, City of Tulare 0.9 1 8,450 1,045,461 153 California City WWTP California City, City

of Kern 1.5 8,385 874,792 201 Montecito WWTF Montecito SD Santa Barbara 0.83 1 9,107 1,093,775 215 L. Arrowhead WWTF Lake Arrowhead CSD San

Bernardino 0.3 1.7 6,870 482,961 227 Delano WWTF Delano, City of Kern 4.4 4.4 40,801 1,107,978 229 Alan Horton WWTF Mission Springs WD Riverside 1.2 2.5 16,582 1,114,000 251




PRESENT

FLOW

(MGD)

DESIGN

FLOW

(MGD) POP

SERVED ANNUAL

KWH MAX KW COMMENT

Santa Paula WWTF Santa Paula, City of Ventura 1.9 2.9 26,601 1,037,599 338 Blythe Regional WWTF Blythe, City of Riverside 1.5 2.4 10,273 1,314,794 344 Mammoth Community WWTF

Mammoth Community WD Mono 1.4 2.2 20,185 1,627,788 347 kWh and kW estimated

Adelanto WWTP Adelanto, City of San Bernardino 2.5 18,130 2,171,099 349 Beaumont WWTF Beaumont, City of Riverside 1.1 1.4 8,076 2,591,401 371 Palm Springs WWRF Palm Springs, City of Riverside 11 81,945 1,700,428 384 Railroad Canyon WWTP

Elsinore Valley MWD Riverside 1.15 1.2 2,252 1,325,611 399 Third party Aggregator

Coastal WWTF South Orange County Wastewater Authority Orange 4.2 6.7 15,048 2,303,334 420

IEUA Regional Plant NO.2

Inland Empire Utilities Agency San Bernardino 5 x 634,648 424

Porterville WWTF Porterville, City of Tulare 4.6 4 32,600 2,056,403 428 San Jacinto Regional WRF

Eastern MWD Riverside 7.8 11 78,449 2,072,288 452 Third party Aggregator

Goleta WWTF Goleta Sanitary District Santa Barbara 5.7 9 39,962 2,217,891 452

China Lake WWTF Ridgecrest, City of Kern 2.2 3 25,406 2,056,403 479 kWh and kW estimated Big Bear Area Regional WWTF

Big Bear Area Regional Wastewater Agency

San Bernardino 2.26 3.2 11,987 2,056,403 479 kWh and kW estimated

Carpentaria WWTF Carpentaria Sanitary District Santa Barbara 1.3 2.5 16,500 1,940,781 489

Moorpark WWTP Ventura County Wastewater Works Dist No. 1 Ventura 1.72 3 25,000 2,751,573 529

Ojai Valley WWTF Ojai Valley SD Ventura 1.8 2.5 16,300 2,879,528 562 Temecula Valley Regional WRF

Eastern MWD Riverside 8 12 10,459 2,959,102 588 Third party Aggregator

Hanford WWTF Hanford, City of King 4.2 5 27,683 4,419,436 664 Saugus WRP Los Angeles CSD Los Angeles 4.1 6.5 58,036 3,796,480 724 Corona WWTF #2 aka Sunkist

Corona, City of Riverside 3 3 x 2,999,686 793




PRESENT

FLOW

(MGD)

DESIGN

FLOW

(MGD) POP

SERVED ANNUAL

KWH MAX KW COMMENT

Victor Valley Regional WWRP

Victor Valley Wastewater Reclamation Authority

San Bernardino 10.7 11 94,268 3,851,328 836

Redlands WWTF Redlands, City of San Bernardino 3.8 6 41,724 2,164,810 886

Lake Elsinore Regional WWTP

Elsinore Valley MWD Riverside 6.9 8 49,807 6,653,506 899

kWh provided by owner, Third party Aggregator

Rialto WWTP Rialto, City of San Bernardino 7.4 11 60,960 6,218,972 912

Regional WWTP South Orange County Wastewater Authority Orange 13 123,559 2,267,069 1,108

Visalia WWTP Visalia, City of Tulare 12 17 59,721 4,072,426 1,112 Pomona WRP Los Angeles CSD Los Angeles 8.8 15 x 6,638,707 1,120 Palmdale WRP Los Angeles CSD Los Angeles 9.2 15 122,000 5,604,227 1,126 Yucaipa Valley WD WWTP

Yucaipa Valley WD San Bernardino 4.3 4.5 31,900 4,067,888 1,192

Hill Canyon WWTF Thousand Oaks, City of Ventura 9.9 10 117,005 4,150,038 1,224

IEUA Carbon Canyon WRF

Inland Empire Utilities Agency

San Bernardino 8.7 10 x 6,400,124 1,232

Simi Valley WWTP Simi Valley, City of Ventura 9 13 89,825 7,549,516 1,279 Los Alisos WRP Irvine Ranch WD Orange 4.5 7.5 19,204 7,233,820 1,392 Lancaster WRP Los Angeles CSD Los Angeles 13.2 16 105,000 7,979,033 1,409 Sun City WWTF Eastern MWD Riverside 2.4 3 17,000 6,287,944 1,568 Third party Aggregator Western Riverside Co Reg WWTP

Western MWD Riverside 3 8 0 9,784,876 1,664

Long Beach WRP Los Angeles CSD Los Angeles 20.4 25 x 8,155,790 1,714 San Bernardino WWTF San Bernardino, City

of San Bernardino 22 28 172,501 6,416,305 1,728



San Bernardino 5.8 15 x 9,595,120 1,824

Moreno Valley Regional WRF

Eastern MWD Riverside 11.2 16 180,466 10,258,256 1,888 3rd party Aggregator

Oxnard WWTF Oxnard, City of Ventura 19 32 225,000 7,757,496 2,016

Talking with third party aggregator

Corona WWTF #1 Corona, City of Riverside 9 11.5 149,387 11,009,482 2,069




PRESENT

FLOW

(MGD)

DESIGN

FLOW

(MGD) POP

SERVED ANNUAL

KWH MAX KW COMMENT

Perris Valley Regional WRF

Eastern MWD Riverside 3.9 11 46,600 11,971,324 2,080 Third party Aggregator

Tapia WRF Las Virgenes MWD Los Angeles 9.5 16 62,000 13,467,710 2,613

Talking with third party aggregator

Los Coyotes WRP Los Angeles CSD Los Angeles 32 38 x 12,795,743 2,662 Valencia WRP Los Angeles CSD Los Angeles 14 17 73,600 15,381,463 2,688 Eastside WRF San Buenaventura,

City of Ventura 9.3 14 106,000 7,949,945 2,829 Tulare WWTF Tulare, City of Tulare 4.3 5 31,359 16,472,140 2,848 Michelson WRP Irvine Ranch WD Orange 13.5 17 156,899 17,953,874 2,986 Whittier Narrows WRP Los Angeles CSD Los Angeles 7.8 15 x 5,383,365 4,019 IEUA Regional Plant NO.4


San Bernardino 5.3 7 x 18,754,008 4,048



San Bernardino 39 44 850,000 14,288,538 4,080

Palm Desert WWRF Coachella Valley WD Riverside 10 18 65,000 14,403,714 6,225 OCSD STP NO 2 Orange CSD Orange 153 208 2,500,000 12,960,216 6,480 OCSD WWTF NO 1 Orange CSD Orange 90 168 x 15,982,002 6,576 San Jose Creek Los Angeles CSD Los Angeles 84 100 x 24,074,549 8053 kWh and kW provided by owner Joint Plant Los Angeles CSD Los Angeles 320 400 3,500,000 2,330,516 19,480 Total 1,079 1,515 9,903,158 406,666,908 120,541

x = Population is aggregated and assigned to one STP



DESCRIPTIVE STATISTICS OF THE STPS WITH IN SCE’S SERVICE AREA

PROFILE OF ALL STPS AS A GROUP Table 2 presents a descriptive profile of the 80 major STPs. The 80 STPs have a combined dry weather design flow of approximately 1,500 MGD. The individual STPs range in design flow from 1 to 400 MGD. It is estimated that the current total flow from these treatment facilities is approximately 1, 100 MGD. The total maximum MW for these 80 STPs is estimated to be 120. From 1 July 2007 to 30 June 2008 these STPs used a total of 407,000 MWh. It is estimated that these treatment plants serve a population of approximately 9.9 million.

TABLE 2. PROFILE OF THE MAJOR STP INDUSTRY WITHIN SCE’S SERVICE AREA

ELEMENT VALUE

No. of Agencies with STPs 56

No. of Agencies with 2 or more 9

No. of STP 80

Total MW 120

Total MWh, 1 July 07 – 30 June 08 407,000

Total Dry Weather Design Flow (MGD) 1,515

Total Current Dry Weather Flow (MGD) 1,080

Total Population Served (Million) 9.9

Table 3 provides a description of the median major STP. In general, the description of this median STP would be in the more urbanize counties serviced by SCE or the medium sized cities within the rural areas of the SCE service area such as the City of Tulare.

TABLE 3. PROFILE OF THE MEDIAN MAJOR STPS WITHIN SCE’S SERVICE AREA

ELEMENT VALUE

Dry Weather Design Flow (MGD) 6

Total kW 626

Annual MWh, 1 July 07 – 30 June 08 2,671

kW/MGD 112

Annual MWh/MGD 461

Population Served 50,000


STPS PROFILE BY KW CATEGORIES The information from Table 1 which is ranked in ascending order of the maximum kW was grouped into three kW categories. There were 17 small (20-200 kW) STPs which is 21 percent of the total STPs. There were 25 medium (>200 – 500 kW) STPs which is 25 percent of the total STPs. There were 43 large (>500 kW) STPs making up the remaining 54 percent. The data within these groups were used to generate a profile in these three kW categories and is summarized in Table 4. When normalizing the kW and annual MWh by the design flow MGD, one can see that these data for the medium and large kW category were relatively similar.

TABLE 4. DESCRIPTIVE STATISTICS OF THE MAJOR STPS GROUPED BY KW CATEGORIES

MAX KW

NO. OF

STPS %

MEDIAN

SIZE

(MGD)

SIZE

RANGE

(MGD) MEDIAN

KW RANGE OF

KW MEDIAN

KW/MGD

MEDIAN

ANNUAL

MWH

RANGE

ANNUAL

MWH

MEDIAN

ANNUAL

KWH/MGD

<200 17 21 1.3 0.99 -11 89 32-153 102 413 112-1,045 317,754 200-500 20 25 2.7 1-11 365 201-479 134 1,664 483-2,591 530,966

>500 43 54 12.5 2.5-400 1,603 529-19,480 120 7,234 2,165-24,075 589,759

Table 4 indicates for the three kW categories, the facilities range from 10 to more than 100 times the design flow. This implies that the kW needed per MGD varies widely for these 80 treatment facilities.

Some of the determining factors that could reduce the kW requirement and provide a lower MWh/MGD ratio include, but are not limited to the following:

Handling solids at another facility;

Using ponds for secondary treatment instead of activated sludge;

Using anaerobic digesters that generate biogas to power aeration blowers or generate electricity on-site;

Using solar panels, internal combustion engines, turbines, microturbines, or fuel cells to generate electricity;

No tertiary treatment that typically requires re-pumping (in some cases more than 700 kW) to meet tertiary distribution pressures of > 80 psig; and

Tertiary wastewater pump stations (in some cases 700 to 900 kW) owned by a different agency and on a different electrical meter.

Some of the determining factors that demand more kW and increase the MWh/MGD ratio include, but are not limited to the following:

Needing a large initial lift if the topography of the collection system is relatively flat. To create a hydraulic grade so it can operate by gravity flow implies a relatively deep collection system near the treatment plant thereby requiring a very large initial lift to get the wastewater to flow through the various treatment units.

Digesting solids using an aerobic instead of anaerobic digestion process;

Making oxygen on-site for pure oxygen instead of normal aeration activated sludge;

Using centrifuges instead of belt filter presses to dewater sludge;



Using tertiary treatment such as UV disinfection, membrane bioreactors, micro-filtration, reverse osmosis and fluidize bed filtration instead of conventional secondary treatment followed by chlorine disinfection and gravity filtration;

Using nutrient removal processes such as nitrification/denitrification, modified Ludzack-Ettinger (MLE), Anaerobic/Anoxic/Oxide (A2O), and Bardenpho processes that are used to meet low total nitrogen discharge requirement. For example the MLE process requires a recirculation rate of the secondary effluent of 3 times while the Bardenpho process requires a recirculation rate of 5 times. So for a 10 MGD treatment plant, the MLE process requires the pumping of an equivalent 30 MGD while a Bardenpho process requires the pumping of an equivalent 50 MGD. These recirculation rates extend the contact time of the liquid to the biological solids so that the nitrogen and in some cases the phosphorous can be biologically stripped out of the wastewater; and

Tertiary treatment and pump stations are owned by a single agency and on the same site and electrical meter.




APPLICABLE DEMAND RESPONSE SCENARIOS FOR THE SEWAGE TREATMENT INDUSTRY

For this project there were five scenarios identified. These are summarized below with a more detailed discussion of these scenarios.

Use of emergency diesel back up generators (Not a practical option).

Use available storage.

Turn down the blowers of the activated sludge treatment process.

For facilities with a fat, oil, and grease (FOG) collection program, add FOG to an anaerobic digester approximately 1 hour before a demand response event increases the biogas production which would in turn increases the electrical generation output.

Become your own third party aggregator.

SCENARIO CONSTRAINT - CARBON FOOTPRINT SCE has a policy of not encouraging options that increase the carbon footprint. The carbon footprint for producing 1 MWh of electricity was used to determine whether an option met this criterion.

In 2006 SCE’s carbon footprint was 641.26 pounds of carbon dioxide per MWh of generation

750~1,250 pounds of carbon dioxide per MWh for using only natural gas for generation (http://www.carma.org/ )

~1,750 lb/MWh of carbon dioxide per MWh for diesel power generation (http://www.carma.org/ and http://bioenergy.ornl.gov/papers/misc/energy_conv.html

EMERGENCY DIESEL BACK UP GENERATORS This option is applicable only if it meets the following two requirements:

This operation must meet the regional air quality permit rules.

This option must have a lower carbon footprint than the current SCE footprint for 1 MWh of electricity

For this option, 1 MWh generated by diesel had a carbon dioxide footprint that was 2.7 times larger than the 2006 SCE’s footprint. Based on this information, this option was eliminated from further consideration.

http://www.carma.org/


http://bioenergy.ornl.gov/papers/misc/energy_conv.html



STORAGE Many facilities have storage, but few have these facilities in a strategic location to use in a demand response event on a routine basis. Below are some desirable locations.

After the primary clarifiers -- to minimize cleaning and to equalize flow to the secondary aeration process thereby allowing turning off a blower during the noon to 6 PM time frame for a two hour duration.

After the secondary clarifiers -- to minimize cleaning and allow locking out or reducing the tertiary pumping system during the noon to 6 PM time frame for a two hour duration (typically if the flow equalization is to optimize the aeration process, this flow equalization can not typically be used for a demand response event, see the below subsection for more discussion).

Utilizing storage is one of the more complex scenarios to execute if this alternative is not part of the original design for the system. Storage can have unintended consequences such as changes in solids loading rates to the down stream processes. These changes were typically viewed unfavorable by the operational staff during the site visits. There are some site-specific cases that provide some savings, but this scenario, in general, is not a widely available option for most treatment facilities.

REDUCTION IN AERATION Aeration is the largest uses of electrical power at a STP. There are two ways to lower the total power requirement for this process.

Flow equalization ahead of the secondary aeration process

Adjusting aeration to track the hydraulics of the diurnal flow fluctuations

FLOW EQUALIZATION TO OPTIMIZE THE AERATION PROCESS Many nutrient removal processes such as MLE, A2O, and Bardenpho have flow equalization, because the process requires long retention times. It is estimated that about 20 percent of the STPs in SCE’s service area use these processes. Instead of building reactors which are expensive from a capital perspective, the engineering community typically uses a recycling flow equalization approach. Under these design conditions and when the current flow is more than 50 percent of design capacity, there is no option to use the flow equalization to lower the aeration requirement. All the capacity is used up to process the sewage in a timely manner.

ADJUSTING AERATION TO MATCH DIURNAL HYDRAULICS Adjusting the aeration to match the hydraulics of the system is an easier scenario to manage for a demand response event. Figure 2 is a typical hydraulic daily flow profile for a 2.7 MGD average daily flow facility for a bedroom community. The diurnal flow has two peaks and two valleys.

FIGURE 2. EXAMPLE OF DIURNAL FLOW FOR A BEDROOM COMMUNITY SERVICE AREA WITH A 2.7 MGD AVERAGE FLOW WITH CORRESPONDING TOU ELECTRICAL RATES

Demand Res 08.03


ponse Feasibility Study for the Sewage Treatment Industry DR

0

0.4

0.8

1.2

1.6

2

2.4

2.8

3.2

3.6

4

4.4

12:00AM

2:00AM

4:00AM

6:00AM

8:00AM

10:00AM

12:00PM

2:00PM

4:00PM

6:00PM

8:00PM

10:00PM

12:00AM

Off Peak Mid Peak On Peak Mid Peak



The highest peak flow occurs at about 10 AM followed by a valley at 3 PM. The second lower peak occurs at about 7 PM and the lowest flow occurs at 4 AM. If the STP uses two or more electrical blowers, it may be possible to turn off one blower during the 3 PM valley and still meet the aeration requirements of the process. These blowers can consume up to 375 kW electrical demand for a STP treating 10 MGD of flow. More than two STPs during the site visits indicated a willingness to examine this option. Two STPs that are already on board with a third party aggregator also use this option as part of their strategy to shed load during a demand response event.

FAT, OIL, AND GREASE Fat, oil, and grease (FOG) when added to an anaerobic digester generate additional biogas within 45 minutes. In order to use this approach, the STP must have the following elements in place:

A FOG collection program

A FOG receiving station

Anaerobic digestion of solids

Biogas with electric power generation

There are at least two agencies within SCE’s service area that have all these elements in place. There are more than 50 percent of the utilities with the last two elements in place. FOG is a concern in the collection system since it is a known cause for sewers to overflow and generate fines for permit violations from the Regional Water Quality Control Boards. However, the infrastructure (the first two items identified above) to implement this scenario is currently lacking. It is estimated that this scenario may be a more viable option in the 2 to 5 year time frame because regulations that require pre-treatment FOG traps and collection by a third party and infrastructure, a FOG receiving station at the STP, are required..

LOCKING OUT NON-24/7 PROCESSES The two major processes that are covered by this option are solids dewatering and tertiary pumping.

In general, the solids dewatering process for plants under 50 MGD is not a 24/7 operation. However, the equipment associated with this activity is relatively small. For example a 2-meter filter belt press which can handle 5 MGD typically runs two shifts 5 days a week. The total kW associated with this size belt filter press and all the other associated equipment is approximately 40 kW. To make the return on capital investment worthwhile, this process would have to be part of an integrated approach consisting of more components so the total kW would approach a 1,000 kW, making it cost-effective relative to the intended effort.

During the site visits, large pumps were used to boost the tertiary line pressure to the reclamation distribution system. Line pressures for these systems can be as high as 120 psig and require pumps totaling 700-900 kW. Locking these during the noon



to 6 PM time frame for 2 hours may be an option if irrigation is the major use for the reclaimed system.

BECOMING A THIRD PARTY AGGREGATOR During the site visits it became apparent that the STP was only one component managed by the owner agency. In a later portion of this report 24 potential agencies are identified as having enough kW at a STP to make it worth the potential economic incentives to shed load during a demand response event. Approximately 80 percent (19 out of 24 agencies) have water pump station, water treatment facilities, and wastewater pump stations. By becoming their own aggregator, these agencies would be able to manage all their facilities in a manner to potentially shed substantial loads during a demand response event.

This option was not explored during the site visits so the feasibility of this scenario is unclear. In addition, it should be noted that in many agencies, the water and wastewater elements are managed and operated by different teams that may be based in different departments and perspectives. For example, the operational staff needs different certifications from the state of California to operate a water or wastewater treatment facility. This is also the case for operation of the water distribution or the wastewater collection system. Coordination and viewing the system as a whole could be a difficult task due to the complexity and in some cases competing organizational issues.



UPPER MANAGEMENT PRESENTATIONS AND SITE VISITS

INITIAL CONTACT Table 5 summaries the 16 utilities that were contacted to make upper management presentations. These utilities operate 32 facilities (40 percent of the 80), treat 1,256 MGD (83 percent of the 1,505 MGD), and serve 8.2 million (83 percent of the 9.8 million). There was only one facility <200 kW, 4 facilities in the 200-<500 kW category, and 27 facilities in the >500 kW category.

TABLE 5. PROFILE OF AGENCIES CONTACTED FOR UPPER MANAGEMENT PRESENTATIONS

ELEMENT SCE’S SERVICE

AREA

UPPER

MANAGEMENT

PRESENTATION

AGENCIES

PERCENT OF ALL

STPS WITHIN

SCE’S SERVICE

AREA

No. Agencies 56 16 29

No. STPs 80 32 40

Total Power (MW)

120 86 72

Total Annual Energy (MWh) 406,667 268,876 66

Total Design Flow (MGD) 1,515 1,256 83

Population Served (million) 9.9 8.2 83

DESCRIPTION OF 10 UPPER MANAGEMENT PRESENTATION AGENCIES

Upper management presentations were made to 10 agencies. Table 6 summarizes the final list of 10 agencies, the counties in which they are located, and the staff and their respective titles. The profile of these treatment plants were more weighted towards the >500 kW facilities because of the economic benefit from a demand response for the <500 kW facility is small when compared to the effort and the impact on the facility.

For the City of Fillmore, American Water Company is a private operator of the system under contract with the City of Fillmore. Any change in operations would



have to be approved by both the City of Fillmore and American Water Company because there is an energy performance agreement in their contract. Generally, the City of Fillmore allows the American Water Company to develop acceptable operational practices. In some cases, savings developed are shared between the two parties.

TABLE 6 SUMMARY OF AGENCY, COUNTY LOCATION, AND STAFF THAT ATTENDED UPPER MANAGEMENT PRESENTATIONS

NAME OF AGENCY COUNTY STAFF AND TITLES

Carpentaria Sanitation District

Santa Barbara

Craig Murray, General Manager

Coachella Valley WD

Riverside Dan Parks, Assistant to General Manager; Stephen Edwards, Energy/Electrical Coordinator

City of Fillmore Ventura Rick Barnes, Sr. Construction Engineer/ Engineering Technical Services, American Water; Tom Peterson, Project Manager, American Water

Irvine Ranch WD Orange Wayne Posey, Director of Wastewater Operations; Mark B. Gingras, Operations Manager, Michelson; Noah Sanchez, Operations Manager, Los Alisos

City of Oxnard Ventura Ken Ortega, Public Works Director; Tony Emmert, Water Resources Manager; Mark Norris, Utilities Services Manager/Assistant Public Works Director; Thien Ng, Senior Engineer

South Orange County Wastewater Authority

Orange Mike Wilson, Assistant General Manager; Robert Waters, Chief Operator Regional Plant.

Ventura County District No. 1

Ventura Satya Karra, Manager of Operations for Water and Sanitiation; Eric Keller, Project Engineer

City of Ventura Ventura Ms Vicki Musgrove, Utilities Director; Dan Pfeifer, Wastewater Superintendent

Elsinore Valley MWD

Riverside Phil Miller, District Engineer; Ted Eich, Wastewater Operations Manager; Mitch Pierson, Regional Plant Manager; Sudhir Mohleji, Senior Civil Engineer; Imad Baiyasi, Senior Civil Engineer

City of Thousand Oaks

Ventura Chuck Rogers, Wastewater Superintendent; Mike Tohidian, Senior Civil Engineer, Public Works; Mike Lambert, Operations Manager; Jim Brandt, Shift Supervisor



DESCRIPTION OF UPPER MANAGEMENT PRESENTATIONS A 15 slide Power Point presentation was developed. An example is presented in Appendix A and was the one presented to Irvine Ranch Water District. After each presentation, a project memo was generated that summarized the highlights of the meeting with the upper management. Appendix A also contains an example of the project memo summarizing the meeting with Irvine Ranch Water District. Slides were devoted to the following areas:

The Cal ISO electrical demand projections system for 2 and 24 hours ahead as well as the three alert stages (1, 2 and 3);

A description of this project and its objectives;

Potential strategies for shedding load;

The facility or facilities ranking(s) within the 80 STPs with respect to MGD, annual kWh, and kWh/MGD;

Potential cost savings; and

Permission to conduct a site visit to determine how the facility might response to a demand response event.

GENERAL REACTIONS TO THE PRESENTATIONS Table 7 is a profile of the facilities of these agencies. The last row of this table provides a comparison to all the STPs within SCE’s service area to put this list of STPs in perspective. From this list of agencies, eight agencies agreed for site visits of their facilities. All agencies were very positive about trying to reduce energy costs and explore opportunities to save operational costs.

Information gathered from the upper management presentation indicated the following:

The language in a grant from SCE for the solar panels installed at the City of Thousand Oaks’ STP does not allow their participation in a voluntary demand response program.

Elsinore Valley Municipal Water District recently became a member of a voluntary demand response program sponsored by a third party aggregator

South Orange County Wastewater Authority has two facilities within SCE’s service area and three facilities within San Diego Gas and Electric’s service area. At least one of the facilities serviced by SDG&E is participating in a voluntary demand response program.

City of Oxnard is having discussion with a third party aggregator

As can be seen from this information, the STP industry (40 percent of the agencies participating in these upper management meetings are already doing something) is relatively pro-active in reducing their costs of electrical energy.



TABLE 7. PROFILE OF AGENCIES THAT PARTICIPATED IN UPPER MANAGEMENT PRESENTATIONS

UPPER MANAGEMENT

PRESENTATION AGENCIES

NO. OF

STPS TOTAL MGD TOTAL KW ANNUAL KWH POPULATION

SERVED

Carpentaria Sanitation District 1 2.5 358 1,940,781 10,189

Coachella Valley WD 1 18 6,225 14,403,714 60,241

Elsinore Valley MWD 2 9.2 1,298 7,979,117 52,059

Fillmore, City of 1 1.3 93 413,080 12,497

Irvine Ranch WD 2 22.5 4,378 25,187,694 176,103

Oxnard, City of 1 32 2,016 7,757,496 225,000

South Orange County Wastewater Authority 2 20 1,528 4,570,403 138,607

Thousand Oaks 1 10 1,224 4,150,038 117,005

Ventura County District No. 1 1 3 529 2,751,573 25,000

Ventura, City of 1 14 1,603 7,949,945 90,119

Total 13 133 19,252 77,103,841 906,820

Percentage of All SCE STPs 16.3% 8.8% 15.9% 18.9% 9.2%

RESULTS OF SITE VISITS Table 8 summarizes the nine facilities that had site visits. The last row in this table compares the totals of these facilities with the 80 facilities within SCE’s service area. Five (55 percent) indicated they could potentially reduce their loads during a 3-5 PM timeframe. Four facilities (45 percent) indicated that they could not shed any load. A summary of the 4.1 MW load that could potentially be taken off the grid during a demand response event is summarized in Table 9. Figure 3 presents the percentage for the four scenarios of demand response load reduction for these plants described below:

Reduction in aeration

Reducing pumping


Locking out tertiary treatment (filtration, chlorination, and pumping to the reclamation distribution system)

Other

1.03 MWReduce pumping

25%

806 kWReduce aeration

20%

112 kWOther

3%

2.18 MW Reduce/lock out tertiary

52%

FIGURE 3. DISTRIBUTION OF POTENTIAL SHEDDING OF MW BY LOAD REDUCTION SCENARIO




TABLE 8. DESCRIPTION OF STPS THAT WERE SITE VISITED

SITE VISIT AGENCIES TOTAL

MGD TOTAL

KW ANNUAL KWH POPULATION

SERVED PROCESS DESCRIPTION

Carpentaria Sanitation District

2.5 489 1,940,781 16,500 Activated sludge, aerobic sludge digestion, belt filter press, no tertiary treatment

Coachella Valley Water District

18 6,224 14,403,714 60,241 No primary treatment, Activated sludge, belt filter presses, tertiary filters and high and low pressure pump stations

City of Fillmore 1.3 93 413,080 12,497 Activated sludge, belt filter presses, no tertiary treatment Irvine Ranch WD – Michelson Plant

17 3821 17,953,874 176,103 Activated sludge, no solids handling (sent to Orange County Sanitation District)

Irvine Ranch WD – Los Alisos Plant

5.5 1928 7,233,820 40,000 Waste Lagoons, no routine solids handling

South Orange County Wastewater Authority – Regional Plant

13 1,108 2,267,069 138,607 Activated sludge, Solids from Coastal and 3A STPs, anaerobic digesters, belt filter presses

South Orange County Wastewater Authority – Coastal Plant

6.7 420 2,303,334 40,000 Activated sludge, no solids handling (sent to Regional Plant)

Ventura County District No. 1

3 529 2,751,573 25,000 Activated sludge, belt filter presses, tertiary filters and pump station

City of Ventura 14 3,794 7,949,945 106,000 MLE Activated sludge, anaerobic digesters, belt filter presses, flow equalization is used but has to be pumped back to headworks, tertiary treatment

Site Visit Totals 81 18,406 57,217,190 614,948 Percentage of All SCE STPs 7.4% 16.8% 16.0% 8.5%



TABLE 9. SUMMARY OF POTENTIAL LOAD BY CATEGORY IDENTIFIED FROM NINE SITE VISITS THAT COULD POTENTIALLY BE TAKEN OFF THE GRID

AGENCY COACHELLA VALLEY WD

CITY OF SAN BUENA-VENTURA

CARPINTERIA SANITARY DISTRICT IRVINE RANCH WD

SOUTH ORANGE COUNTY WASTEWATER AUTHORITY

CITY OF FILLMORE

VENTURA COUNTY DISTRICT NO 1

FACILITY NAME WRP 10

VENTURA WRF

CARPINTERIA WWTP

MICHELSON WRP

LOS ALISOS WRP REGIONAL COASTAL

FILLMORE WRP

MOORPARK WWTP TOTAL

% OF TOTAL

Reduce aeration (kW) 373 373 60 806 19.5 Reduce pumping (kW) 112 900 20 1,032 25.0 Reduce/lock out tertiary (kW) 984 750 447 2,181 52.8

Other (kW) 60 45 7 112 2.7 Total DR Potential (kW) 1,529 418 0 900 750 0 0 534 0 4,131 100 Typical Operating (kW) 2,850 1,951 360 2,195 1,268 1,243 490 956 858 12,171 DR kW Potential of Typical Operating kW (%) 53.7 21.4 0.0 41.0 59.2 0.0 0.0 55.9 0.0 33.9 Max Load (kW) 6,224 2,814 487 3,803 1,928 3,171 1,274 1,246 1,564 22,511 54.1



The 4.1 MW represents 34 percent of the total typical operating load of 12.2 MW. The typical total operating load was 55 percent of the total maximum available load, 22.5 MW at these nine facilities.

More than 95 percent of the tertiary treatment load is associated with pumping needed to send the reclaimed water back out to the reclamation distribution system. In some cases such as the Southern Orange County Wastewater Authority (SOCWA), the reclaim pump stations are operated by SOCWA but owned by another agency. If the agency decided to become their own aggregator, these two facilities may be able to reduce their load by including these pump stations.

Grouping the tertiary treatment with the pumping category results in over 75 percent associated with some sort of pumping. The aeration and pumping activities makes up over 95 percent of the potential load that can be reduced by these STPs.

Due to tertiary water rules established by the California Department of Public Health, much of the irrigation of areas such as golf courses, public parks and schools, must be done during the evening to reduce potential pathogen exposure to the public. Most of the pumping (95 percent of the kW) to maintain tertiary distribution system pressure is typically required after 6 PM. But periodically, due to some use during the day, one or two pumps can turn on in response to a drop in distribution line pressure.

In some cases, planning is required to create enough on-site storage to allow a pump to be taken off line. For the aeration option, vane adjustment coupled with diurnal flow patterns may allow a STP on a case by case basis to turn off one blower if multiple blowers are typically used.

Solids handling, although not a 24/7 process at most plants under 50 MGD, does not require a lot of kW to operate. It was approximately 50 percent of the “Other” load in Figure 5. So although this process can be locked out during a demand response event, the potential load is typically less than 100 kW. Including this process for most plants is of marginal benefit.

ESTIMATED DEMAND RESPONSE PARTICIPATION BY THE SEWAGE TREATMENT INDUSTRY

The current system of economic incentives is based on the amount of kW that is taken off the grid when there is a demand response event. Based on this perspective, the upper management of these STPs has indicated that a program that offers demand reduction rebates in the tens of thousands of dollars per month is worthy of their considerations. This implies that a program that has a unit cost of tens of dollars per kW taken off the grid would require >500 kW to be taken off the grid.

Based on the above analysis, agencies with a total <500 kW would have to shed almost their entire load to meet the thousands of dollars per month saving threshold. No STP can achieve this unless they shifted to their emergency back up generators. STPs are not allowed to make this shift for a voluntary demand response program due to regulatory air permit rules. Based on this criterion, 37 STPs as summarized in Table 6 and shown in Figure 4 were eliminated from participating in a voluntary demand response program.


POTENTIAL PARTICIPATION BY 43 STP, >500 KW There are 43 STPs that have enough kW to potentially participate in a demand response program. These can be divided into two groups: (1) facilities that are not currently available to be part of a SCE program, and (2) facilities that are potential candidates as shown in Figure 4.

<500 kW not Available

3746%

> 500 kW Available22

28%

>500 kW Not Available

2126%

FIGURE 4. DISTRIBUTION OF STPS ESTIMATED TO BE AVAILABLE TO PARTICIPATE IN A SCE DEMAND RESPONSE PROGRAM

NOT AVAILABLE FOR PARTICIPATION (21 STPS) There are 21 STPs are either part of a third party aggregator demand response program, had no interest, had no DR potential as determined by a site visit, or was prohibited by grant language that help capitalize solar panels. These facilities are summarized in Table 10.



TABLE 10 PROFILE OF 19 FACILITIES THAT ARE NOT LIKELY TO PARTICIPATE IN A DEMAND RESPONSE PROGRAM

AGENCY FACILITY

DESIGN FLOW (MGD)

ANNUAL KWH KW COMMENT

Eastern MWD Sun City WWTF 3 6,287,944 1,568 Part of a third party aggregators

Eastern MWD Perris Valley Regional WRF

11 11,971,324 2,080 Part of a third party aggregators

Eastern MWD Temecula Valley Regional WRF

12 2,959,102 588 Part of a third party aggregators

Eastern MWD Moreno Valley Regional WRF

16 10,258,256 1,888 Part of a third party aggregators

Elsinore Valley MWD

Lake Elsinore Regional WWTP

8 6,653,506 899 Part of a third party aggregators

Los Angeles CSD Saugus WRP 6.5 3,796,480 724 Phoned, no interest Los Angeles CSD Pomona WRP 15 6,638,707 1,120 Phoned, no interest Los Angeles CSD Palmdale WRP 15 5,604,227 1,126 Phoned, no interest Los Angeles CSD Whittier Narrows

WRP 15 5,383,365 4,019 Phoned, no interest

Los Angeles CSD Lancaster WRP 16 7,979,033 1,409 Phoned, no interest Los Angeles CSD Valencia WRP 17 15,381,463 2,688 Phoned, no interest Los Angeles CSD Long Beach WRP 25 8,155,790 1,714 Phoned, no interest Los Angeles CSD Los Coyotes WRP 38 12,795,743 2,662 Phoned, no interest Los Angeles CSD San Jose Creek

WRP 100 24,074,549 6500 Phoned, no interest

Los Angeles CSD Joint Plant 400 2,330,516 19,480 Phoned, no interest Orange CSD STP NO 1 168 15,982,002 6,576 Phoned, no interest Orange CSD STP NO 2 208 12,960,216 6,480 Phoned, no interest South Orange County Wastewater Authority

Regional Plant 13 2,267,069 1,108

Site visit indicated no opportunities

City of Thousand Oaks

Hill Canyon WWTF

10 4,150,038 1,224

Solar panel grant does not allow participation in a voluntary demand response program

City of Ventura Eastside WRF 14 7,949,945 2,829 Site visit indicated no opportunities

Ventura County, District No. 1

Moorpark WWTP 3 2,751,573 529 Site visit indicated no opportunities

AVAILABLE FOR PARTICIPATION (22 STPS) The remaining 22 STPs are potential candidates to participate in an SCE demand response program and are listed in Table 11. Although the City of Oxnard had some contact with a third party aggregator, we were still invited to perform a site visit. This site visit could not be schedule in time to be included in this report, but has been included as one of the potential 22 shown in Figure 4 and Table 11.



TABLE 11. LIST OF POTENTIAL AGENCIES AND FACILITIES THAT MAY PARTICIPATE IN A VOLUNTARY DEMAND RESPONSE PROGRAM

AGENCY FACILITY

DESIGN

FLOW

(MGD) ANNUAL KWH KW Las Virgenes MWD Tapia WRF 16 13,467,710 2,613 City of Oxnard Oxnard WWTF 38 7,757,496 2,016 Coachella Valley WD Palm Desert WWRF 18 14,403,714 6,225

City of Corona Corona WWTF #2 aka Sunkist

3 2,999,686 793

City of Corona Corona WWTF #1 12 11,009,482 2,069 City of Hanford Hanford WWTF 5 4,419,436 664 Inland Empire Utilities Agency


7 18,754,008 4,048


IEUA Carbon Canyon WRF

10 6,400,124 1,232



15 9,595,120 1,824



44 14,288,538 4,080

Irvine Ranch WD Los Alisos WRP 5.5 7,233,820 1,392 Irvine Ranch WD Michelson WRP 17 17,953,874 2,986 Ojai Valley Sanitary District

Ojai Valley WWTF 2.5 2,879,528 562

City of Redlands Redlands WWTF 6 2,164,810 886 City of Rialto Rialto WWTP 11 6,218,972 912 City of San Bernardino San Bernardino WWTF 28 6,416,305 1,728 City of Simi Valley Simi Valley WWTP 13 7,549,516 1,279 City of Tulare Tulare WWTF 5 16,472,140 2,848 Victor Valley Wastewater Reclamation Authority

Victor Valley Regional WWRP

11 3,851,328 836

City of Visalia Visalia WWTP 17 4,072,426 1,112

Western MWD Western Riverside Regiona WWTP

8 9,784,876 1,664

Yucaipa Valley WD Yucaipa Valley WD WWTP

4.5 4,067,888 1,192

Total 305 196,779,439 44,598 Italics = Site visit indicated potential to participate in a demand response program.

The breakdown of the 22 potential STPs >500 kW is the following:

1 – Talking with a third party aggregator

3 – Identified as likely participants from site visits

18 – Status unknown

From the above list, it is assumed that the agency talking with a third party aggregator and the ones identified as likely participants from the sites visits would



participate in a SCE demand response program. An additional five STPs is projected using a conservative 30 percent participation rate (a 55 percent participation rate was observed in the 9 site visits).

The total estimated number of STPs is 11 (9 from the >500 kW and 2 from the <500 kW as indicated by site visit data) that would participation in a SCE demand response program. The 11 would represent a total of 14 percent of the 80 STPs in the SCE service area. Adjusting for the six STPs already participating with a third party aggregator, put the potential participation rate at 15 percent, i.e., 11 out of 74 STPs.

ESTIMATED MW REDUCTION DURING A DEMAND RESPONSE EVENT

An estimate for the load that could be shed by the six STPs that are already in a third party demand response program was beyond the scope of this project. No attempt was made to develop an estimate for these six STPs for this report.

It is estimated that the 11 STPs projected to be part of a SCE demand response program could reduce their load by approximately 6.1 MW. This number was estimated assuming the following:

4.1 MW from the five site visits

2 MW from the six STPs projected to be participants (a median operating load of 1.3 MW each with the ability to shed an average load of 25 percent).

LIKELY STP DEMAND RESPONSE PROGRAM ELEMENTS Based on the upper management presentations the following features that would attract participation are summarized in Table 12.



TABLE 12. SUMMARY OF DEMAND RESPONSE PROGRAM FEATURES TO ENCOURAGE STP PARTICIPATION

FEATURE COMMENT

More SCE outreach in explaining the options and programs

Most managers were not aware of demand response or were mistaken it with permanent load reduction.

A higher $/kW $17.10/kW was too low for small plants. In two cases, they have two shifts and have to pay overtime with a 2-4 hour minimum to turn back on the equipment and they are unwilling to do this based on current rates. The monthly savings would have to be in the thousands before management would consider making these types of changes.

Reduce or eliminate penalties

Two STP are participating in a third party program, in part, due to this feature. Maybe SCE could offer a longer, no penalty trial period so they can gain experience with the demand response program.

Two hour period to drop load, preferably in the 3 -5 PM range

A few participants mentioned 6 hours was too long a period to reduce or lock out processes or equipment.

Assistance in estimating cost savings for dropping load under current programs

Upper management wants to know whether the benefit is worth the effort



FINDINGS AND RECOMMENDATIONS FOR IMPLEMENTATION

FINDINGS Below is a summary of the findings for this study.

There are 80 major STPs in SCE’s service area.

Upper management of STPs is not familiar with most aspects of demand response.

For the same kW category, there was a range from 10 to 100 fold in the design flow rates indicating a non-standard design and unit process approach for this industry (see Table 4).

The most likely scenario for a STP to participate in a demand response program is a facility with more than 500 kW and tertiary treatment.

Power associated with pumping has the highest potential for load reduction in response to a demand response event

Six out of the 80 STPs in SCE’s service territory currently participate in a third party demand response program.

It is estimated that 11 STPs (15 percent of the remaining 74 STPs) would participate in a SCE demand response program.

These 11 facilities would reduce load by an estimated 6.1 MW during a demand response event.

A demand response program that encourages STP participation should have the following elements:

More SCE outreach in explaining the options and program incentives and benefits

A higher $/kW Reduce or elimination of penalties or a longer phase in of the program

so the STP industry can make the appropriate adjustments A shorter two hour period to drop load, preferably in the 3 -5 PM range More SCE assistance in estimating cost savings for dropping load under

current or a future program designed for the STP industry



RECOMMENDATIONS FOR IMPLEMENTATION The following recommendations are suggested for implementation:

An outreach program to educate the STP industry would result in more STP participation.

Develop a visitation program with a team approach consisting of members with expertise in STPs and the appropriate SCE account representatives that could develop the cost savings for the demand response scenarios. Three phases are recommended and described below.

Phase 1. The focus of this phase would be to follow up with the STPs that participated in the site visits of this study and that showed an interest in participating in a SCE demand response program

Phase 2. Prioritize the list of STPs that were not visited in this study and perform a presentation and site visit.

Phase 3. Determine whether there are any opportunities with the 200-500 kW group of STPs to perform a presentation and site visit.



REFERENCES California Air Resources Board, California Climate Action Registry, ICLEI-Local

Governments for Sustainability, and the Climate Registry, Draft, Local Government Operations Protocol, 19 June 2008



http://www.epa.gov/cwns/ (Website for the Clean Watershed Needs Survey database)




http://www.epa.gov/cwns/



APPENDIX A

mand Response Feasibility Study for the Sewage Treatment Industry DR 08.03


IRVINE RANCH WATER DISTRICT UPPER MANAGEMENT PRESENTATION

De



IRVINE RANCH WATER DISTRICT PRESENTATION MEMO

Kennedy/Jenks Consultants

16 October 2008

Memorandum

To: Project File

From: L. Leong

Subject: IRWD Upper Management Meeting K/J 08530004

On 16 October 2008 Kennedy/Jenks Consultants staff of Larry Leong and Ken Petersen met with IRWD Staff to discuss the SCE project. Wayne Posey, Director of Wastewater Operations Mark B. Gingras, Operations Manager, Michelson Water Reclamation Plant Noah Sanchez, Operations Manager, Los Alisos Water Reclamation Plant The presentation was well received and there were a lot of ideas floated as to how they might participate in a Demand Response program. The DR response will primarily focus on delaying pumping during the 3-5 PM time period. They do not have solids handling and SCAQMD limits the use of their natural gas fired IC engines. I indicated that SCE’s policy does not allow them to use the IC engines for a voluntary DR because the carbon foot print of a MW generated by this means is almost twice that of a MW from SCE’s grid. Arrangement for site visiting their two facilities has been initiated.

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