HomeMy WebLinkAboutVallecitos Water District; 2003-08-20;AGREEMENT FOR SALE OF RECYCLED WATER
AND USE OF MAHR RESERVOIR BETWEEN
THE VALLECITOS WATER DISTRICT AND
THE CARLSBAD MUNICIPAL WATER DISTRICT
This Agreement is made and entered into by and between the VALLECITOS
WATER DISTRICT (“VALLECITOS”), organized and existing pursuant to Water Code
section 30000 et seq., and the CARLSBAD MUNICIPAL WATER DISTRICT
(“CARLSBAD”), a Public Agency organized under the Municipal Water Act of 19 1 1, and
a subsidiary district of the City of Carlsbad organized and existing pursuant to Water Code
section 7 1000 et seq. (collectively, the “Parties”).
RECITALS
A. On June 13, 1991, the Parties entered into an agreement (the “1991
Agreement”) for the sale of recycled water fiom the VALLECITOS’ Meadowlark
Reclamation Facility (“MRF”). Since July 199 1, VALLECITOS has provided recycled
water to CARLSBAD in accordance with the terms and conditions of the 1991 Agreement.
t I
B. VALLECITOS is currently in the process of evaluating an expansion of the
MRF and the increase in production fiom two (2) million gallons per day (“MGD”) of
recycled water to a potential of five (5) MGD.
C. VALLECITOS also owns, operates, and maintains the Mahr Reservoir, which
has the capacity to store fifty-four (54) million gallons (“MG”) of recycled water and is
located within the boundaries of both VALLECITOS and the City of Carlsbad.
D. CARLSBAD is in the process of developing an expansion of its recycled water
system referred to as the EncinaBasin Water Reclamation Program, Phase I1 Project (“Phase
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11 Project”). CARLSBAD desires to use the Mahr Reservoir for seasonal, operational
(diurnal), and emergency storage as part of the Phase I1 Project. The scheduled dates for
implementation of the Phase I1 Project is July 2005.
E. VALLECITOS agrees to allow CARLSBAD to use a portion of the storage
capacity of Mahr Reservoir, provided CARLSBAD constructs certain improvements to the
Mahr Reservoir. The storage capacity available to CARLSBAD in the Mahr Reservoir shall
be up to 32 MG, provided CARLSBAD purchases from VALLECITOS an additional one
(1) MGD of recycled water (for a total of 3 MGD) as part of the Phase I1 Project.
F. CARLSBAD acknowledges that delivery of the recycled water volume
outlined in this Agreement is contingent upon the expansion of the MRF by VALLECITOS
and sufficient development within VALLECITOS and build out ofthe Meadowlark area and
drainage basin to provide enough effluent to produce the recycled water.
NOW, THEREFORE, the Parties agree to the following terms and conditions:
1. Construction of Mahr Reservoir Immovements. CARLSBAD shall be
responsible for constructing and installing certain improvements (the “Improvements”) that
include, but may not be limited to, the draining and cleaning of the interior storage area of
the Mahr Reservoir, installing a chlorination system and aeration system, modifLing the
inledoutlet works, and installing an asphalt concrete liner and floating polypropylene cover
as further described in the Encina Basin Recycled Water Distribution Study prepared by
CGvL Engineers in association with John Powell & Associates, Inc., dated May 2000 (the
“Study”). A copy of the Study is attached to this Agreement as Exhibit “A” and incorporated
herein by reference. VALLECITOS has reviewed the Study and consents to the
recommended Improvements and other pertinent improvements. CARLSBAD shall provide
VALLECITOS with sixty (60) days written notice prior to beginning construction of the
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improvements. Construction of the Improvements shall be subject to coordination with
VALLECITOS staff. The schedule to construct the Improvements is based on CARLSBAD
receiving a commitment for funding from the State of California in 2003, whereby
construction would begin in 2003 and extend through 2004.
2. Funding and Desim of Improvements. CARLSBAD shall construct the
Improvements with funding obtained from state and federal loans and grants. CARLSBAD
shall be responsible for the design and preparation of the plans and specifications for the
Improvements and will obtain any necessary permits on behalf of VALLECITOS and with
the written consent of VALLECITOS, which consent shall not be unreasonably withheld.
All plans and specifications for the Improvements shall be submitted to VALLECITOS for
review and approval, which approval shall not be unreasonably withheld. CARLSBAD
shall construct the Improvements in accordance with the approved plans and specifications
and permit conditions including compliance with CEQA and all other regulatory bodies.
The Improvements shall become the property of VALLECITOS and shall be dedicated to
VALLECITOS for operation and maintenance. If funding for the Improvements is not
approved by the State of California, then CARLSBAD is not obligated to design or construct
the Improvements. In the event the Improvements are not constructed, for whatever reason,
all rights of CARLSBAD to purchase recycled water beyond 2 MGD and to utilize storage
in the Mahr Reservoir shall terminate in the discretion of VALLECITOS.
3. Mahr Reservoir Storage Capacity. CARLSBAD shall have the right to utilize
up to 32 MG of storage capacity available in the Mahr Reservoir for its Phase I1 Project.
In the event CARLSBAD discontinues the purchase of recycled water from VALLECITOS,
the use of storage capacity of the Mahr Reservoir shall automatically revert to
VALLECITOS. CARLSBAD shall be allowed to utilize Mahr Reservoir for peak demands
in accordance with the approved Operations and Maintenance manual referenced in Section
5. In no event shall CARLSBAD have any priority in Hydraulic Grade Line (HGL) or
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available capacity of the reservoir and shall be entitled to up to a maximum of 60% of the
storage available at any given time.
4. Master Flow Meters. Master recycled water flow meters (“Master Flow
Meter(s)”) shall be installed by CARLSBAD at or near the MRF, in locations mutually
agreeable to the Parties, to measure the quantity of recycled water supplied to CARLSBAD
from the MRF. VALLECITOS shall be responsible for operating, maintaining, calibrating,
and reading the Master Flow Meter(s) on a routine basis. VALLECITOS shall read and
report to CARLSBAD the meter results no less than once per month and shall provide
copies to CARLSBAD of calibration results on an annual basis. VALLECITOS shall
deliver recycled water to CARLSBAD to the mutually agreed upon locations of the Master
Flow Meter(s) and shall have no responsibility or obligation to deliver recycled water
beyond the Master Flow Meter location(s).
5. Ownershin ODeration. and Maintenance of Mahr Reservoir Immovements.
VALLECITOS shall own, operate, and maintain the Mahr Reservoir and all Improvements
constructed for the Mahr Reservoir. A draft operation and maintenance manual shall be .
prepared by CARLSBAD for review, and approval by VALLECITOS, for operation and II
maintenance of the Improvements, which will be incorporated in an operations and
maintenance manual for the operation of MRF, Mahr and the Failsafe pipeline.
VALLECITOS shall operate the Improvements in conformance with the approved
operations and maintenance manual. Notwithstanding the foregoing, in no case shall
VALLECITOS be required to operate the Improvements in a fashion that will be harmhl
or detrimental to the operation of the MRF, Mahr Reservoir, or the Fail Safe pipeline.
6. ODeration and Maintenance of Other Related Facilities. VALLECITOS shall
own, operate, and maintain, per the approved operations and maintenance manual, the
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recycled water transmission pipeline identified on the attached Exhibit “B,” which is
incorporated herein by reference.
Each party shall grant to the other necessary easements and rights-of-way to construct,
operate and maintain the recycled water facilities described in this Agreement that they
respectively control and assist each other to obtain easements or rights-of-way on lands
controlled by other entities not subject to this Agreement.
7. Failsafe Pipeline Capacitv and Operation. CARLSBAD acknowledges
and agrees that under certain operational scenarios, the full production of MRF may exceed
the failsafe pipeline capacity of 3 MGD and to accommodate operational goals, the Mahr
Reservoir may be at capacity with no additional, available storage. To accommodate such
an event, CARLSBAD agrees, per the approved operations and maintenance manual, to
provide adequate facilities and operational flexibility to VALLECITOS to dispose of the
additional flow into the CARLSBAD recycled water distribution system for either use or
disposal. Disposal of recycled water through the CARLSBAD system is subject to and
predicated upon the availability of adequate capacity at the Encina Wastewater Authority
(EWA) flow equalization facility and coordination with EWA. All excess recycled water,
beyond purchases required in Section 8 and peak demands, shall meet the quality
requirements contained in Section 10. The method of disposing shall be identified in the
operational parameters agreed upon between the Parties.
CARLSBAD agrees to completely remove the existing Phase I Pump Station, located at El
Camino Real, prior to or concurrent with the initial delivery of 3 mgd of recycled water in
accordance with Section 8. CARLSBAD agrees to replace the existing 12-inch Failsafe
pipeline with like pipeline material in accordance with VALLECITOS standards.
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8. Ouantities of Recycled Water to be Purchased. During the term of this
Agreement, CARLSBAD agrees to purchase, and VALLECITOS agrees to deliver to the
CARLSBAD recycled water distribution system (provided flows are sufficient), the
following minimum mounts of recycled water from the MRF:
a. Prior to completion of the Phase I1 Project, CARLSBAD shall continue
to purchase a minimum of 2 MGD of recycled water which is approximately 2,240 acre-feet
per year.
b. Upon completion of the Phase I1 Project, and provided VALLECITOS
has completed the expansion of the MRF and adequate effluent is available, CARLSBAD
agrees to purchase a minimum of 2 MGD of recycled water during the months of December,
January, February, and March and 3 MGD of recycled water for the remaining months which
is approximately 2,989 hcre-feet per year.
9. Intermt>tion of Deliver?, of Recycled Water. Notwithstanding the
provisions of section 8 above, the Parties understand and agree that there shall be no liability
to VALLECITOS to supply recycled water, or obligation of Carlsbad to purchase recycled
water for day-to-day interruptions in delivery of recycled water due to plant emergencies
requiring plant shut down and repairs associated with acts of God, permit compliance, orders
by regulatory bodies or judicial courts, and/or equipment breakdowns, or substantial
maintenance activities. VALLECITOS shall make good faith efforts to resume delivery of
recycled water in a timely manner after completing the necessary efforts to restore the
operation of MRF. If recycled water delivery is discontinued for more than seven (7)
consecutive days, then VALLECITOS shall provide CARLSBAD a time schedule indicating
when delivery is expected to resume.
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10. Treatment Standards. VALLECITOS shall treat the recycled water from the
MRF in conformance with the water quality requirements as provided by Title 22, Division
4, of the California Code of Regulations (“CCR”), section 60305, “Use of Recycled Water
for Impoundments,” intended as a source of supply for non-restricted recreational
impoundments suitable for body contact in compliance with the criteria specified in CCR
section 6030 1.230(b) for “Disinfected Tertiary Recycled Water” (Title 22). VALLECITOS
shall use its best good faith efforts to ensure that said recycled water meets the forgoing
CCR Title 22 standards, however, VALLECITOS does not guarantee or warrant the quality
of the recycled water provided CARLSBAD or subsequent users. Both Parties understand
that the presence of dissolved minerals in the recycled water is measured as total dissolved
solids (TDS) and other substances in higher concentrations can be deleterious to the plants
irrigated with such water. Both Parties agree that VALLECITOS’ failure to supply recycled
water with TDS concentration of less than 1000 milligrams per liter (MG/L), as determined
in conformance with the methodology specified in the Encina Waste Pollution Control
Facility Waste Discharge Permit, will be grounds for CARLSBAD to suspend its obligation
to accept and pay for recycled water from VALLECITOS until quality is restored to less
than 1000 MG/L TDS.
VALLECITOS agrees to limit the total chlorine residual to 10 parts per million (ppm)
or less, based upon a 24 hour period average, for recycled water discharged from the MRF.
This limitation shall not be applicable to water discharged to the VALLECITOS Failsafe
pipeline.
The Parties fbrther recognize that during periods of drought VALLECITOS may
experience lower flow as a result of conservation efforts. However, the amounts of salts
received would not decrease and can cause the TDS levels to rise. During such drought
periods as designated by the Metropolitan Water District (“MWD”) and/or the San Diego
County Water Authority (“Water Authority”), the Parties agree that recycled water with TDS
concentration of no more than 1200 MG/L will be an acceptable quality to CARLSBAD
under the terms of this Agreement.
1 1. Recvcled Water Delivery Pressure. Recycled water delivered by
VALLECITOS to the CARLSBAD distribution system shall not be at a guaranteed
minimum pressure. However, the following hydraulic grade line (“HGL”) shall be met for
recycled water discharges from the MRF to the Mahr Reservoir facility. Discharge pressure
for delivery at the Mahr Reservoir shall be equivalent to a minimum HGL of 550 feet,
including all pipeline headloss, with an operational HGL goal of 590 feet to maximize
operational flexibility.
12. Compliance With Rerrulatorv Requirements. CARLSBAD agrees to comply
with all applicable recycled water distribution regulations issued andor mandated by the
State of California Department of Health Services (DHS), the County of San Diego
Department of Environmental Health (DEH), and the California Regional Water Quality
Control Board, San Diego Region (Regional Board). CARLSBAD shall be responsible for
insuring that all users of recycled water within CARLSBAD’s jurisdiction shall be in
compliance with CARLSBAD’s discharge order issued by the Regional Board, and that all I
users shall be made to comply with CARLSBAD’s most recent recycled water rules and
regulations.
13. Price of Recycled Water. Through Fiscal Year 2003/2004, CARLSBAD shall
purchase, disinfected tertiary recycled water from VALLECITOS at the rate of Three
Hundred Sixty-One Dollars ($361 .OO) per acre-foot, and CARLSBAD shall pay
VALLECITOS for the recycled water based on quarterly statements submitted by
VALLECITOS. Beginning Fiscal Year 2004/2005 the purchase cost shall be based on the
table for Pre-Expansion Annual Cost for the MRF Tertiary Facilities listed in Exhibit “C”.
Upon completion of the MRF expansion, and initial delivery of 3 MGD to CARLSBAD,
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CARLSBAD shall purchase, in accordance with section 8@), disinfected tertiary recycled
water from VALLECITOS using the table for Post-Expansion Annual Cost for MRF
Tertiary Facilities listed in Exhibit “C.” CARLSBAD shall pay VALLECITOS the annual
cost in twelve (1 2) equal payments throughout each fiscal year. Both the Pre-Expansion and
the Post-Expansion Annual Costs shall be based on VALLECITOS’ budgeted figures as of
the beginning of each fiscal year and adjusted to actual costs through retrospective
adjustments after the conclusion of each fiscal year. The recycled water cost shall be
adjusted on July 1 of each year during the term of this Agreement to reflect CAFUSBAD’S
proportionate share of the budgeted operational, overhead, and capital recovery costs for
the MRF Tertiary Facilities, Lift Station No. 1, and Mahr Reservoir as shown in Exhibit “C”.
VALLECITOS will provide CARLSBAD thirty (30) days’ advance written notice of any
changes in the annual cost. VALLECITOS will bill or credit CARLSBAD annually for
retrospective adjustments to reflect actual water delivery costs incurred. CARLSBAD will
be notified of the retrospective adjustment by November 30 of each fiscal year and the
adjustment credithnvoice shall be due and payable within 30 days of said date. At any time
during the term of this agreement, the price of the recycled water shall not exceed seventy-
five percent (75%) of CARLSBAD’S wholesale cost of potable water from the San Diego
County Water Authority. I
The definitions for terms used in this section 13 and Exhibit “C” follow:
MRF Facilities - Wastewater treatment, filtration, disinfection, conveyance,
storage and effluent pumping facilities shown on Exhibit “B”. Also known as Meadowlark
Reclamation Facility (MRF).
I
MRF Tertiary Facilities - Filtration, disinfection, and effluent pumping
facilities relating to Tertiary Treatment at the MFW.
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Mahr Reservoir - A 54 million-gallon earthen reservoir used to store tertiary
treated recycled water located as shown on Exhibit “B”.
Lift Station No. 1 - Components associated with the existing lift Station used
to divert sewage to the MRF for treatment and production of recycled water.
Overhead - Wastewater Department Overhead - General, administrative and
overhead costs incurred within the Wastewater Department not directly associated with the
collection, conveyance and treatment of wastewater.
Pre-Expansion Cost - This includes all costs associated with the operation and
maintenance of the MRF Tertiary Facilities, Lift Station No. 1, Mahr Reservoir and
identified capital recovery costs, shown in Exhibit “C” under the title “Pre-Expansion
Annual Cost.”
Post-Expansion Cost - This includes all costs associated with the operation
and maintenance of the MRF Tertiary Facilities, Lift Station No. 1, Mahr Reservoir and
capital recovery costs shown in Exhibit “C” under the title “Post-Expansion Annual Cost.”
These costs will apply after VALLECITOS has begun the initial delivery of 3 mgd to
CAFUSBAD.
14. Terms of Payment. CARLSBAD shall be invoiced by VALLECITOS on a
monthly basis for the minimum delivery scheduled amounts plus any amounts that exceed
the minimum amounts. CAESBAD agrees to pay VALLECITOS for such purchases
within thirty (30) days of invoice receipt. In the event that payment is more than thirty (30)
days in arrears, VALLECITOS reserves the right to stop delivery of recycled water until
payment is made and charge interest of one percent (1%) per month on delinquent amounts.
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15. Right to Sell to OthersLJtilization of Storage. In the event CARLSBAD fails
to purchase the minimum quantities of recycled water as required in section 8 of this
Agreement, VALLECITOS shall have the absolute right and discretion to sell the unused
recycled water to other parties. Any amounts sold by VALLECITOS to other parties shall
be deducted from any remaining amounts that CARLSBAD is obligated to purchase
pursuant to section 8 of this Agreement. In addition, in the event CARLSBAD fails to
purchase the minimum quantities of recycled water as required in section 8 of this
Agreement, all rights of CARLSBAD to utilize storage in the Mahr Reservoir shall revert
to VALLECITOS and VALLECITOS shall have no obligation or liability to reimburse
CARLSBAD for the cost of the Improvements. Provided, however, in the event
VALLECITOS willfully refuses to provide recycled water to CARLSBAD, when available,
prior to complete depreciation of the Improvements identified in section 1 “Construction of
Improvements,” VALLECITOS shall reimburse CARLSBAD for the lesser of the fair
market value or the undepreciated value of the Improvements. In the event VALLECITOS
uses or sells recycled water to additional parties, VALLECITOS will reimburse or credit
CARLSBAD with up to forty percent (40Y0)of the cost of the improvements, based upon a
ratio of water sold to CARLSBAD and total sales, of the annual depreciated value of the
Improvements identified in Section 1 based upon a thirty (30) year useful life. The
reimbursement or credit shall be in accordance with the annual review of the price of the
recycled water in accordance with Section 13.
16. Access to Records. The Parties shall each keep proper books and records in
which complete and correct entries shall be made of all recycled water delivered to
CARLSBAD throughout the duration of this Agreement. These books and records shall,
upon written request, be subject to inspection by any duly authorized representative of each
party and of the Regional Board.
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17. Notices. Notices required or permitted under this Agreement shall be given
in writing and may either be served personally upon the party to whom it is directed or by
deposit in the United States Mail, postage pre-paid, certified, return receipt requested,
addressed to the Parties’ following addresses:
CARLSBAD: Carlsbad Municipal Water District
163 5 Faraday Avenue
Carlsbad, CA 92008
Attention: Public Works Director
VALLECITOS: Vallecitos Water District,
201 Vallecitos de Oro
San Marcos, CA 92069
Attention: General Manager
18. Assignment. This Agreement or any interest therein or any monies due or that
are to become due thereunder shall not be assigned, hypothecated, or otherwise disposed of
without the prior written consent of both Parties to this Agreement, which consent shall not
be unreasonably withheld. This Agreement shall become effective on the date it is executed
by the Parties.
19. Term of Agreement. The term of this Agreement shall be twenty-two (22)
years from the effective date, subject to the rights of the Parties to an earlier termination as
provided in this Agreement. This Agreement shall continue in force from year to year after
the initial 22-year term until either party gives one (1) year’s written notice to the other of
its intention to terminate or renegotiate the Agreement. This Agreement shall terminate one
(1) year from the date upon which such written notice is received unless the Parties agree
otherwise in writing.
20. Earlv Termination. If at any time during the term of this Agreement recycled
water in compliance with the standards referenced herein cannot lawhlly be used by
CARLSBAD for the purposes intended by this Agreement, because of government
12 July 24, 2003 (10 59AM) G \DATA\WPU)OLWCL~VIS~M~~~O~ agr wpd
regulations now in effect or hereinafter imposed, or, if CARLSBAD should for any reason
breach its obligations under this Agreement in any material respect, including, but not
limited to, failure to pay for recycled water as required, failure to accept recycled water as
required, failure to maintain facilities, or other substantial failure, VALLECITOS may
terminate this Agreement with no further obligation by giving sixty (60) days’ written notice
thereof to CARLSBAD. During said sixty (60) day period, CARLSBAD shall have the
opportunity to cure the breach in the Agreement before termination occurs. In the event
VALLECITOS refuses to deliver recycled water to CARLSBAD in conformance with this
Agreement for any reason, CARLSBAD may terminate this AGREEMENT with no further
obligation upon sixty (60) days’ written notice thereof to VALLECITOS.
2 1. Entire Agreement. This Agreement constitutes the entire understanding
between the Parties with respect to the subject matter hereof superseding all negotiations,
prior discussions, agreements, and understandings, written or oral, including the 1991
agreement. This Agreement shall not be amended, except by written consent of the Parties,
and no waiver of any rights under this Agreement shall be binding unless it is in writing
signed by the party waiving such rights. In the event any provision of this Agreement shall
be held to be invalid and unenforceable, the other provisions ofthis Agreement shall be held
to be valid and binding on the Parties.
22. Binding Effect. This Agreement shall be binding upon the Parties and their
respective successors in interest, permitted assigns, executors, administrators, and personal
representatives.
23. Indemnification. VALLECITOS agrees, to the hllest extent permitted by law,
to indemnifj and hold CARLSBAD, its directors, officers, employees, or authorized
volunteers harmless from any damage, liability, or cost (including attorney’s fees and costs
of defense) to the extent caused by VALLECITOS’ negligent acts, errors, or omissions in
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the performance of work pursuant to this Agreement, including such negligent acts, errors,
or omissions by subcontractors or others for whom VALLECITOS is legally liable.
CARLSBAD agrees, to the fullest extent permitted by law, to indemnifL and hold
VALLECITOS, its directors, officers, employees, or authorized volunteers harmless from
any damage, liability, or cost (including attorney’s fees and costs of defense) to the extent
caused by CARLSBAD’s negligent acts, errors, or omissions in the performance of work
pursuant to this Agreement including such negligent acts, errors, or omissions by
subcontractors or others for whom CARLSBAD is legally liable.
24. Venue. In the event of any legal or equitable proceeding to enforce or
interpret the terms or conditions of this Agreement, the Parties agree that venue shall lie only
in the courts in or nearest to the North County Judicial District, County of San Diego, State
of California.
25. Counterparts. This Agreement may be executed in any number of
counterparts, each of which shall be deemed an original, but all of which, taken together,
shall constitute one and the same instrument.
July 24, 2003 (I 0 59AM) G UJATA\WPWLDOC\reviredMahrO6 agr wpd 14
IN WITNESS WHEREOF, the Parties hereto have caused this Agreement to be
executed and effective as of ~l~;u~-f 20 ,2003.
“VALLECITOS”: “CARLSBAD”:
VALLECITOS WATER DISTRICT
Trish Hannan
President President
By: 1
ATTEST:
General Manager
Date: /03
July 24. ?M)j I IO 59AM) G UJATA\WPWOLDOC\revisedMahr06 apr wpd 15
Carlsbad Municipal Water District
Preliminary Design for the
Encina Basin Phase I1 Recycled Water Distribution System
MAHR RESERVOIR EVALUATION
in Association John Powell 8 Associates, Inc
Consulting Civil Engineers CCVL
ENGINEEGS
&lay 2000
Exhi bit "A"
CHAPTER 1 BACKGROUND ........................................................................ 1-1
Mahr Reservoir Physical Properties ............................................................... 1-1
Mahr Reservoir Operational Issues ................................................................ 1-4
Other Seasonal Storage Reservoirs ................................................................ 1-4
CHAPTER 2 BASIS OF EVALUATION ....................................................... 2-1
.. .. ........... .................... ...................... Facility Sizing Criteria ........................... : e 2-r.
Demand Criteria ....... : ............................... ............... ............................ 1.2-1 .....
System Pipeline Cntena ................................ : 2-2 ................................................... ................................ ..... . Project Cost Data ;; i 2-2
Construction Costs ........................................ :: ...... : ................. 1 ................ 2-2
Cost Index and Price Escalation ....... ::: ..................................................... 2-3 ...
Construction Contingencies .............................................................. i ...... 2-3
Engineering and Administration ; 2-4 ..
CHAPTER 3 SUPPLY/DEMAND/STORAGE ANALYSIS ......................... 3-1
... .. .. ..................... ..... ................ ..... ....
... ....
...
.. ... ..
...... .. ........... ..................................................
..
Seasonal Storage ............................................................................................ 3-1
Demands ................................................................................................... 3-1
Supplies ................................................... 1 ................................................. 3-2
.. .. ..
..
.... Seasonal Balancing ............................................................................. 3-3
Emergency Storage .......................................................................................... 3-4
CHAPTER 4 FACILITY ALTERNATIVES ................................................. 4-1
Possible Facility Improvements ..................................................................... 4-1
Aerati on/Destrati fication S ys tern ............................................................. 4-5
Outflow Microscreening .......................................................................... 4-9
Reservoir Lining and Covering ................................................................ 4-9
Inflow Nutrient Removal .......................................................................... 4-1
Modified J/O Works ................................................................................. 4-2
Outflow Chlorination ............................................................................... 4-8
Miscellaneous Site Work .................................................................. : ..... 4-12
Alternative Combinations of Jmprovements ................................................ 4-12
CGvL ENGINEERS IN ASSOCL4TlON WITH JOHN POWELL & ASSOCIATES I
Table of Contents (Continued)
CHAPTER 5 ALTERNATIVE COSTS AND PHASING ............................. 5-1 .
Mahr Reservoir Use Benefits ......................................................................... 5-1
Comparative Improvement Costs ................................................................... 5-2
Improvement Phasing .................................. ; .................................................. 5-4
CH.APTER 6 RECOMMENDATIONS .......................................................... 6-1
Facilities ......................................................................................................... 6-1
Monitoring I3o.m ....................................................................................... 6-1
APPENDIX A HISTORICAL RECYCLED WATER DEMANDS ............ A-1
APPENDIX B SEASONAL STORAGE MODEL RUNS ............................ B-1
APPENDIX C EMERGENCY STORAGE MODEL RUNS ....................... C-1
LIST OF TABLES
Table 1-1
Table 3-1
Table 3-2
Table 3-3
Table 4-1
Table 4-2
Table 4-3
Table 5-1
Table 5-2
Table 5-3
Table 6-1
Figure 1-1
Figure 1-2
Figure 2-1
Figure 3-1
Figure 4-1
. Figure4-2
Figure 4-3
Figure 4-4
Other Seasonal Storage Reservoir Features ...................................... 1-6
CMWD Recycled Water Supply Availability .................................. 3-3
CMWD Peak-Month SupplyDemand Balance ................................ 3-3
Mahr Reservoir Seasonal Benefits to CMWD .................................. 3-4
Mahr Reservoir YO Hydraulic Parameters ....................................... 4-5
Cost Opinion for Mahr Reservoir VO Works ................................... 4-7
Cost Opinion for Lining and Covering Mahr Reservoir ................. 4-11
Comparative Costs for Mahr Reservoir Phase II Capacity Value .... 5-3
Comparative Costs for Mahr Reservoir Ultimate Capacity Value ... 5-4
Cost Opinion for Initial Mahr Reservoir Improvements .................. 5-5
Mahr Reservoir Monitoring Program ............................................... 621
LIST OF FIGURES
Mahr Reservoir Features ................................................................... 1-2
Mahr Reservoir Volume and Surface Area Curves .......................... 1-3
Engineering News Record Construction Cost Index ........................ 2-3
CMWD Recycled' Water Demand Hydrograph ................................ 3-2
Proposed Mahr Reservoir I/O Works ............................................... 4-4
Upper Os0 Reservoir L/O Works ...................................................... 4-6
Proposed Mahr Reservoir Operations Building Site ........................ 4-8
I
Proposed Mahr Reservoir Improvements ......................................... 4-3
CGvL ENGNEERS IN ASSOCIAT~ON WITH JOHN POWELL & ASSOClizTES 11
. ..
Carlsbad Municipal Water District (CMWD) desires to evaluate the feasibility of
using Mahr Reservoir for seasonal storage in CMWD’s recycled water
distribution system. This evaluation’s purpose is to investigate mitigation for
historical reservoir operational problems, analyze the effect of this storage volume
at various system expansion milestones, evaluate specific reservoir improvements
and determine the best combination to pursue, provide an opinion of probable
cost, and recommend a course of action for implementation.
Mahr Reservoir Physical Properties
Mahr Reservoir is owned and operated by Vallecitos Water District (VWD). The
reservoir is an unlined and uncovered basin formed by a jurisdictional earthen
dam, with a, crest elevation of approximately 598.5 feet. The reservoir bottom
was originally established at approximately 542.5 feet and the spillway elevation
is at approximately 594.5 feet. Possibly to allow for storm retention, the
maximum operating pool was set in the original facility design at approximately
593.0 feet. For this evaluation, to allow for continued submergence of a possible
aeratioddestratification system, and to avoid water quality problems associated
with shallow storage volumes, a minimum operating pool was set at
approximately 555.0 feet, which would maintain a minimum water depth of
approximately 12.5 feet.
The effective working storage volume associated with the difference between the
maximum and minimum pools is approximately 151 acre-feet (AF), or
approximately 49 million gallons (MG). The water surface area at maximum pool
depth is approximately 7.7 acres. Figure 1-1 provides recent photos of the
reservoir dam crest and spillway. Figure 1-2 provides reservoir volume and area
curves in relation to water depth, expressed as feet of.elevation above mean sea
level (amsl).
Inflow and outflow occur through a concrete structure located near the reservoir
bottom at the upstream dam toe. This structure has grated, unvalved ports, and is
serviced by an 18-inch diameter pipeline that passes underneath the dam and
connects with another concrete structure at the downstream dam toe.
CGvL ENGINEERS IN ASSOClATlON WITH JOHN POWELL & ASSOCIATES 1-1
Background
- Dam crest. looking north.
Dam spillway. looking northeast.
Figure 1-1 Mahr Reservoir Features
- CG1.L ENGMEERS 1% XSSOCL4TION WITH JOHS POIVELL & i%SOCIATES 1-2
Background
Mahr Reservoir Volume
A
560
.I
530
0 50 100 150 200 250
Volume, acre-feet
. Mahr Reservoir Surface Area
600
590
580
570
560
550
540
530
0.0 2.0 4.0. 6.0 8.0 10.0
Area, acres
Figure 1-2 Mahr Reservoir Volume and Surface Area Curves
.. . ...
. ,., .. .
..
I
CGvL ENGINEERS IN AssoClATloN WITH JOm POWELL & ASSOCIATES 1-3
Background
Mahr Reservoir Operational Issues
Ongoing water quality problems experienced by vwb prompted installation of
fine screens and implementation of associated procedures at their Meadowlark
Water Reclamation Facility (WRF) for treatment of all water withdrawn from the
reservoir. Wstorically, during normal operation, effluent from the WRF was
pumped to Mahr Reservoir. Outflow from Mahr Reservoir flowed by gravity
through a 20-micron microscreen to remove algae before it was pumped again
into the recycled water distribution system. Microscreen effluent could then
either flow through a chlorine contact tank or directly into the recycled water
distribution system pumping station wet well. However, because of continued
odor and algae complaints by recycled water customers, with Mahr Reservoir as
the suspected source, the reservoir was taken out of service in 1998. Since that
time there have been no further complaints regarding odors and algae.
Other Seasonal Storage Reservoirs
As a basis for comparison, this evaluation reviewed design features and operating
histories of other recycled water seasonal storage reservoirs with volumes
approximately equal to or greater than Mahr Reservoir's. However, relatively
few such seasonal storage reservoirs exist. Three of them are located in Orange
County. Sand Canyon and Rattlesnake Reservoirs are owned and operated by
bine Ranch Water District (IRWD), and have total volumes of 800 AF and
1,200 AF, respectively. Upper Os0 Reservoir is owned and operated by Santa
Margarita Water District (SMWD), and has a total volume of 4,000 AF. All three
reservoirs have been in recycled water service for over 20 years.
The City of Santa Rosa, located in northern California, owns and operates several
recycled water storage reservoirs. The largest has a volume of 2,000 AF and has
been in service for approximately 16 years. Their next two largest. reservoirs have
volumes of 1,100 AF and 700 AF, respectively, and have'been in service for
approximately 22 years. All three reservoirs have relatively flat bottoms, with an
average water depth, when full, of 24 to 25 feet. All three reservoirs are
surrounded by man-made berms, with virtually no tributary drainage area. For
this evaluation, these three reservoirs are designated Santa Rosa A, Santa Rosa B,
and Santa Rosa C, respectively.
.. . .
In discussing design and operation of these reservoirs with respective agency
staff, several features emerge for possible application at Mahr Reservoir:
o Relative size and watershed management of upstream tributary area
o Average water depth of full reservoir
o Combination of treated wastewater with other water supplies
o Nutrient removal from treated wastewater
o Use of multiple-port inletloutlet (UO) works
CGvL ENGLXEERS IN ASSOCMTION WITH JOHN POWELL & ASSOCLATES 1-4
Background
a Use of an aerationldestratification system
o Chlorination of reservoir outflow
o Other treatment of reservoir outflow
o Use of basin lining and covering
Table 1-1 presents a matrix of these features, listed in the same order, and their
invohement at the six above-noted, existing seasonal storage reservoirs. One of
the most significant features to emerge in this evaluation appears to be the relative
size and watershed management of upstream tributary area. By far the most
problematic in this regard of the three reservoirs that have significant tributary
area is Sand Canyon Reservoir. Runoff from a large upstream tributary area
carries in fine, colloidal material and algal nutrients, difficult to treat in reservoir
outflow. Upper Os0 Reservoir appears least problematic in this regard of the
three. The ratio of tributary area to total reservoir volume for Sand Canyon
Reservoir is approximately ten times lager than Upper Os0 Reservoir's ratio.
Mahr Reservoir, like the three Santa Rosa reservoirs, has almost no upstream
tributary watershed area.
Feature
Tributary watershed area
Average water depth
Combined with other supplies
Nutrient removal at plants
Multiple port YO works
Aeration/Des tratificati on
Chlorination of outflow
Other treatment of outflow
Basin lining and covering
!General problem history
a)' Estimated.
b)
C)
Sand
Canyon
Large
15' ft
No
Minorb
Yes
'Yese
Yesg
Yesh
No
Yes
Rattle-
snake
Small
15a ft
Yes
Minorb
Yes
No'
Yesg
No'
NO
No
Upper os0
Small
30 ft
No
No
Yes
Yes
No
NO'
No
No
Santa
Rosa A
None
25 ft
No
Minor'
Yes
No
No
No
NO
No
Santa
Rosa B
None
24 ft
No
Minor'
Nod
NO
NO
NO
No
No
Santa
Rosa C
None
24 ft
No
Minor'
Nod
No '
NO
No
NO
No
Partial nitrificatioddenitnfication practiced at IRWD's Michelson Water Reclamation Plant, but not primarily for
reservoir water quality.
Partial nitrificatioddenitrification practiced at Santa Rosa reclamation plant for last few years, but primarily
motivated by regulatory requirement for winter river discharge.
Have-some turbidity problems with single port and seasonally low water levels.
System installed in 1999 with successful performance.
Water quality tends to be good without aeration, but installation will be evaluated in 2000.
Initially practiced for chemical oxidation of sulfides; later continued partially to maintain a chlorine residual in the
associated distribution system.
Have tried several types of relatively expensive filtration systems, with varied success.
Have only occasionally used Adams strainers.
CGVL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES 1-5
Background
The other significant feature to emerge in this evaluation appears to be the
average water depth of a reservoir when full. Santa Rosa staff reported no
significant algae growth or other depth-related water quality problems when water
depths were predominantly greater than about 8 feet. This meant their three
largest reservoirs only suffered problems on the occasions when they were
drained to within a few feet of their bottoms. Their two smaller reservoirs (not
noted above], with volumes of approximately 200 to 300 AF, have average depths
of about 4 feet and have been regularly plagued with algae and related water
quality problems. The City has employed algae harvesters and barrel filters to
mitigate these problems, with moderate success after considerable effort. Mahr
Reservoir’s average water depth when full is about 25 feet, and the planned
minimal pool depth is 12.5 feet.
Application of the above considerations is explicitly made to Mahr Reservoir in
Chapter 4.
,
CGvL ENGINEERS IN ASSOCLATION WUH JOHN POWELL & ASSOCIATES 1-6
.....
Design criteria and basic cost data presented herein apply to concept and
preliminary level design and layout of recycled .water system components.
Detailed drawings and specifications are not required in such layouts. For this
level, a close approximation of size, location, and cost of various facilities is
developed. As a result, some relocation and resizing of facilities may be required
at a later date as more detailed engineering analyses are made during final design.
Facility sizing is based on future recycled water requirements listed and
developed in Chapter 3. Criteria and standards governing design of proposed
facilities are assumed to use quality design, materials, and construction. Further,
it is assumed that proper attention will be given to considerations such as
appearance, landscaping, operation and maintenance efficiency, and service
reliability. In planning future facility needs, an effort has also been made to
effectively use existing components where practical.
Proposed facilities described in this evaluation are planned as component parts of
a system to serve the projected recycled water requirements of Ch4WD’s
proposed Phase II expansion to a system demand of approximately 5,400 acre-feet
per year (AFY). Some attention is also given to those improvements required for
ultimate expansion to a system demand of approximately 9,800 AFY.
*
Facility Sizing Criteria
Demand Criteria. Monthly demands are used to determine seasonal supply and
storage needs for the recycled water system. The ratio of peak-month to average-
month demand, or peak-month factor, is ultimately used in determining pumping
and operational storage capacities.
Hourly demands are directly used in determining pumping, operational storage,
and pipeline capacities, and are determined by the average-day use during the
peak month, multiplied by the ratio of 24 hours over the length of the regular
daily irrigation period in hours. For example, in calculating peak-hour demands,
the peak-month factor would be multiplied by two if a 12-hour imgation period is
assumed, or multiplied by three if an 8-hour irrigation period is assumed.
CGvL ENGINEERS IN ASSOCIATION WlTH 10” POWELL & AssoCL4ES 2- 1
Basis of Evaluation
Svstem PiDeline Criteria. System piping should be evaluated under all demand
conditions, but performance assessment is typically most critical under peak-hour
demand conditions. Generally, pipelines 1Zinch and greater in diameter are
considered transmission pipelines. Because transmission pipelines impact 1 arge
areas, they can accumulate large head losses from long pipe runs. These large
pipeline friction losses associated with high fluid velocities need to be evaluated
with respect to system delivery capacity, and contribution to lowered system
pressures and excessive energy consumption.
Transmission pipelines are considered undersized if water velocities exceed 3 feet
per second (fps) and head losses exceed 10 feet of head per 1,000 feet of pipe.
Distribution pipelines are considered undersized if velocities exceed 5 fps and
head losses exceed 10 feet of head per 1,000 feet of pipe. However, these criteria
are only a guideline, and higher velocities and head losses may be tolerable under
certain operating conditions such as system emergencies, and within short lengths
of pumping station or reservoir yard piping wherf: impact on system pressure is ’
minimal.
Project Cost Data
Project cost is defined as the total capital investment necessary to complete a
project, including costs for land acquisition, construction, contingencies, all
necessary engineering services, and overhead items such as legal and
administrative services, and financing. Probable construction cost opinions
developed in this report include an allowance of 20 percent for contractor
administrative expense, general overhead and profit (OH&P). Total project
capital cost includes allowance for contingencies at 20 percent, and engineering
and administration at 15 percent.
Construction Costs. Probable construction cost opinions cover materials, taxes,
labor, mobilizatioddemobilization, and services necessary to build proposed
facilities. These costs derive from current or adjusted historical cost information
and are intended to represent median prices anticipated for each type of work.
Cost estimating guides, previous studies, cost curves, and recent contract bids
were used to develop cost infomation.
In an evaluation such as this, cost opinions are considered as defined by the
American Association of Cost Engineers for preliminary design. . These are
opinions made without detailed engineering data and have an expected accuracy
range of plus 30 percent to minus 20 percent. Actual project costs will depend on
future labor and material costs, market conditions, project-specific details, and
other variables. The allowance of 20 percent for contractor OH&P is calculated
from the subtotal of all other construction costs, the addition of which results in
the total construction cost.
I
CGvL ENGINEERS IN ASSOClATlON WITH JOHN POWELL & ASSOChES 2-2
Basis of Evaluation
Cost Index and Price Escalation. Construction costs typically undergo long-
term changes in keeping with corresponding changes in the regional and national
economy. A commonly accepted barometer of these changes has been
Engineering New Record’g Construction Cost Index (ENRCCI), which is
computed from prices of construction materials and labor, and is based on a value
of 100 in the year 1913.
As indicated on Figure 2-1, construction costs have been steadily increasing for
many years. This figure shows ENRCCI’s aggregate rate of increase for 20 major
US cities, which is considered representative of construction costs in the San
Diego area and, therefore, in CMWD. Project and construction costs in this report
are based on a projected ENRCCI of 6,130 for.January 2000 in the San Diego
.. area. .
_. . . - 1o.Ooo
x
E
ul
s
8
-
w 5.000
E 0
0
ul E
- c
2 .L
s
1 .Ooo
Jan-80 Jan-82 Jan-84 Jan-86 Jan-88 Jan-90 Jan-92 Jan-94 Jan-96 Jan-98 Jan-00 Jaw02
Date
Figure 2-1 Engineering News Record Construction Cost Index
Construction Contingencies. A contingency allowance covers uncertainties
associated with project design. Factors such as unusual foundation conditions,
special construction methods, variation in final lengths or average depths of
pipeline, and construction adjacent to existing facilities are just a few of the many
items that may increase construction costs, and for which an allowance is made-in
preliminary design cost opinions. The cost of these items can vary greatly
depending on the type and magnitude of project. An allowance of 20 percent of
total construction cost is assumed to cover such contingencies, the addition of
which results in the subtotal project cost.
‘
Engineering and Administration. The cost of engineering services for ,major
construction projects includes some or all of the following: special investigations,
surveys, foundation explorations, locating interfering utilities, detailed design,
preparing contract documents, construction inspection, office engineering,
materials testing, final inspection, and start-up of the completed project.
Depending on the size and complexity of project, total engineering, legal and
administrative costs may range from 7 to 40 percent of the contract cost. The
lower percentage usually applies to relatively large projects, simple projects, and
~~ CGVL ENGINEERS IN ASSOCIATION WlTH JOHN POWELL & ASSOCIATES 2-3
Basis of Evaluation
those not requiring a large amount of preliminary investigation. The higher
percentage usually applies to smaller projects, projects requiring a great deal of
engineering effort, or those requiring a relatively large amount of preliminary
work. An allowance of 10 percent of subtotal project cost is assumed for this
report.
CMWD administration charges are assumed to cover items such as legal fees,
financing expenses, administrative costs and interest during construction. The
cost of these items can vary, but for the purpose of this evaluation, administration
.charges are assumed to equal approximately 5 percent of subtotal project cost.
The average total cost of all necessary engineering plus administrative services is
therefore assumed to be 15 percent of the subtotal project cost, the addition of .
which results in the total project cost.
..
- CGvL ENGINEERS JN ASSOClATlON WITH JOHN POWELL & ASSOCIATES 2-4
Mahr Reservoir has the potential to provide seasonal, emergency and operational
storage for CMWD’s recycled water system. The first two storage types are
analyzed in this chapter. Operational storage analysis is part of ongoing related
work, but outside this evaluation’s scope. Results of that analysis and those of
this chapter are used in Chapter 5.
Seasonal Storage
Three expansion milestones were selected at which to assess Mahr Reservoir’s
possible seasonal benefit to CMWD’s existing and planned recycled water
system:
Current situation, representing an annual system demand of approximately
1,8OO AFY
Completion of Phase II, representing an annual system demand of
approximately 5,400 AFY
Ultimate expansion, representing an annual system demand of approximately
9,800 AFY I Three CMWD system scenarios were selected to quantify the reservoir’s benefit
at each milestone:
(A) System supply/dernand fully balanced by hypothetical seasonal storage
(B) System supply/demand balanced with no seasonal storage
(C) System supply/demand balanced with Mahr Reservoir working storage
Demands. All scenarios used the same recycled water demand hydrograph,
which was developed from the last five complete years of actual CMWD metered
demand. A listing of monthly demand values and related statistics for the years
1995 through 1999 is provided in Appendix A. Because the months in which
peak and minimum demands occur are not the same from year to year, a simple
average of each month, as shown in the second-to-last row of the table in
Appendix A, does not result in representative factors for accurately modeling and
projecting system demand variations. Rather, it tends to reduce peak demands
and increase minimum demands. Therefore, this simple average was adjusted by
an algorithm to preserve the true average peak-month and minimum-month
factors, which is more representative of historical seasonal fluctuations. This
I
CGvL ENGINEERS tN ASSOCIATION WITH JOHN POWELL & ASSOCIATES‘ 3- 1
adjusted average is shown in the last row of the same table. The resulting
adjusted peak-month factor of 2.10 is used for subsequent facility analysis.
A unit hydrograph was developed for monthly irrigation demands based on this
adjusted five-year system average. Figure 3-1 is a graphical representation of the
adjusted hydrograph. Based on these adjusted factors, July has the representative
peak-month demand and January has the representative minimum-month demand.
This hydrograph is typical of recycled water monthly demand variations and
reflects typical southern California irrigation cycles.
2.50
4 % 1.00
0.00
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov .Dee
Month
Figure 3-1 CMWD Recycled Water Demand Hydrograph
Supplies. Existing and planned CMWD recycled water supply sources include
the following:
o Carlsbad Advanced Wastewater Treatment (AWT) facility, to be constructed
by CMWD at the Encina Water Pollution Control Facility (WPCF), owned
and operated by the Encina Water Authority
o Meadowlark WRF, owned and operated by VWD
o Gafner Water Reclamation Plant (WRP), owned and operated by Leucadia
County Water District
Based on CMWD preferences, for this evaluation it is assumed' that production
capacities of these plants would be used in the order listed above. Estimated
available peak-month plant supply capacities in million gallons per day (MGD)
and acre-feet per month (AFM) for each of the three milestones are listed in Table
3-1. Calculated required plant supply capacities for each scenario, which are
sometimes less, are discussed below.
..
CGvL ENGINEERS IN ASSOCIAT~ON WITH JOHN POWELL & ASSOC~ATE~ 3-2
Supply/Demand/Storage Analysis
Supply Source
Carlsbad AV
Meadowlark WRF
Gafner WRP
Total
Estimated Peak-Month Availability
Current Phase I1 Ultimate
MGD AFM MGD AFM MGD AFM
0.00 0 4.00 374 15.0 1,401
1.70 159 2.00 187 3.0 280
0.75 70 . 2.00 187 2.0 187
2.45 229 8.00 747 20.0 1,868 ,
C
3 - Ultimate
A B
C
Seasonal Balancing. A computerized spreadsheet model of CMWD’s recycled
water system was developed to test monthly supply/demand balances, and the
resulting use of seasonal storage. The model was applied to each of the three
scenarios at each of the three milestones, for a total of nine analyses. For those
analyses using Mahr Reservoir as seasonal storage, reservoir filling was assumed
to occur in January and February, the two lowest demand months. Copies of
these analyses are found in Appendix B and labeled by milestone and scenario:
lA, lB, lC, 2A, 2B, 2C, 3A, 3B, and3C.
.
945 374 187 187 62 136 15 1
1,716 817 0 0 0 899 2,983
1,716 1,401 280 35 0 0 0
1,716 1,401 164 0 0 151 151
I
A critical test for seasonal suppl y/demand balancing is satisfying peak-month
demand, either directly from one or more supply sources, or from a combination
of direct supply and water returned from seasonal storage (reservoir outflow).
Peak-month results in AF from the nine analyses are summarized in Table 3-2.
In assessing Mahr Reservoir’s seasonal benefit to CMWD’s system, it is helpful
to compare the reservoir with an equivalent peak-month supply source, both in
- CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES 3-3
Supply/DemandlStorage Analysis
volume delivered (AF) and equivalent production rate (MGD). The estimated
volume delivered from storage by Mahr Reservoir is shown in the second-to-last
column for Scenario C under each of the three milestones in Table 3-2. It is also a
useful perspective to see what fraction Mahr Reservoir’s storage would represent
of the total seasonal storage needed to fully balance the recycled water system for
each of the three milestones. These data are summarized in Table 3-3. .
Because of production limitations in planned Phase II Meadowlark WRF and
Carlsbad AWT expansions, 62 AF of other supply (probably potable water), in
addition to Mahr Reservoir, would be needed to balance peak-month Phase II
demands under Scenario 2C.
Emergency Storage
Mahr Reservoir’s emergency storage benefit to 0’s system depends on total
recycled water production capacity available, demand on the distribution system,
and volume of water in the reservoir, all at the time of the emergency, and time of
year. Because of such a wide range of variables, only a sampIe analysis was
performed, using the same computerized spreadsheet model noted above. As an
analytical basis, the model was applied to the Phase II milestone Scenario 2C (see
Appendix B), in which the routine seasonal filling of Mahr Reservoir occurred in
January and February. After an assumed emergency draw-down to offset
simulated lost supply in a given month, the model was constrained to refill the
reservoir as quickly as possible so to be full in May, leaving the reservoir
available to provide its full seasonal storage benefit. The simulated supply loss
was constrained to be subsequently offset by recycled water production, up to
maximum available rates, without the use of additional potable water supplement
(beyond that already estimated for Scenario 2C).
..
Given these constraints, there were only three months during which the reservoir
could provide emergency supply: February, March and April. Three simulations
were run, one for an emergency supply loss in each of those three months. Copies
of these analyses are found in Appendix C and captioned by volume and month of
supply loss, all being labeled Scenario 2D. The following emergency storage
(supply loss offset) could be provided by Mahr Reservoir: in February, 149 AF;
in March, 151 AF; and in April, 131 AF:
C&L ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES 3-4
Supply/Demand/Storage Analysis
If water were stored in the reservoir-beyond the minimum operating pool
volume--over more of the year, say starting in the fall, emergency supply could
be available for more months. To maintain the full seasonal benefit discussed in
the previous section, no emergency storage would be available -May through
September. It is important to correctZy condition emergency storage availability,
so as not to inappropriately “double-count” Mahr Reservoir storage for both
seasonal afid emergency purposes.
,
CGvL ENGINEERS IN ASSOCLATION WITH JOHN POWELL & ASSOCIATES 3-5
Possible Facility Improvements
Mahr Reservoir's recycled water system benefit accrues both from seasonal and
emergency storage value, noted in Chapter 3, and operational storage value,
discussed in Chapter 5. To realize these values, facility improvements are
required to mitigate known problems. These improvements could occur at the
reservoir, or at other locations to affect water quality of reservoir inflow and/or
outflow. The following improvements have been considered:
o Removing nutrients from reservoir inflow at the wastewater treatment plants
o Modifying the existing reservoir I/O works, with multiple ports for best
seasonal water stratum selection
a Adding an aeratioddestratification system in the reservoir
o Adding chlorination to reservoir outflow
a Reusing existing microscreens, either at Meadowlark WRF or relocated to
Mahr Reservoir, to remove suspended material from reservoir outflow
a Adding reservoir lining and covering
Wastewater Inflow Nutrient Removal. Phosphorus and nitrogen are
macronutrients for algae and other plant growth. Both constituents are typically
present in wastewater at concentrations many times higher than growth limiting
values. Removing phosphorus from reservoir inflow would typically involve
chemical precipitation as part of primary treatment at a wastewater treatment
plant. Removing nitrogen would typically involve nitrificatioddenitrification as
I part of secondary treatment at a wastewater treatment plant.
While Meadowlark WRF is physically closest to Mahr Reservoir, planned
system-wide recycled water production, as illustrated in Chapter 3, projects
Carlsbad AWT production to dominate the recycled water blend, even in Phase II.
In addition, Gafner WRP's Phase II production is projected to be comparable to
Meadowlark WRF's. Therefore, one or both nutrient removal processes would
have to be implemented at all three plants to substantially control nutrients.
Each nutrient removal process adds significant cost to a wastewater treatment
plant's liquid stream and incidental cost to a plant's solids stream. While
substantial nutrient reduction at each plant would help control algae growth in the
reservoir, the nutrient loss is a disbenefit to the recycled water system's irrigation
CGvL ENGINEERS IK ASSOClATlON WITH JOHN POWELL & ASSOCIATES 4- 1
Facility Alternatives
customers. Various studies have valued the typical wastewater nutrient fertilizer
"credit" at $40 to $50 per acre-foot. Estimating the precise benefit to the reservoir
of a given amount of nutrient removal would require a detailed analysis of the
combined plant effluents and water stored in the reservoir. The analysis would
then determine limiting nutrient quantities, which typically involve very low
concentrations, as treatment process target values. These estimations are beyond
this evaluation's scope, and this candidate improvement is not considered further.
Modified L/O Works. The current reservoir UO works has only one set of
openings around elevation 550 feet, only a few feet above the basin bottom. An
improved YO works would have multiple sets of openings, say four additional,
equally spaced, approximately 9 feet apart vertically. This would allow selective
water withdrawal from the stratum having the seasonally best water quality, e.g.,
avoiding a layer of algae in the top 5-10 feet of water, and avoiding intake of
bottom sediment.
There are two basic TI0 works configurations: a free-standing tower rising from
the reservoir bottom, and a laid-back structure secured to the upstream dam face,
A free-standing tower could in concept be constructed on top of the existing YO
works. A laid-back structure could be connected between the existing UO works
and the toe of the upstream dam face. A review of conceptual design
considerations for the two alternatives indicated the latter alternative would be
less disruptive, probably less expensive, and therefore, preferable. Either YO
modification would require review by the State of California, Division of Safety
of Dams @SOD). Key consideration by DSOD would be maintaining adequate
and controllable reservoir draw-down capability for dam emergencies..
The plan location of the modified I/O works with respect to the existing works
and other existing and proposed reservoir features is shown on Figure 4-1. A
drawing of a laid-back YO structure is shown on Figure 4-2. Four YO port valves
would be provided for selecting the best quality water stratum, and an additional
valve would isolate the existing works. The latter valve would be normally
closed, and this existing opening used as a fifth regular UO port and as an
emergency outlet to satisfy jurisdictional dam draw-down requirements.
Preliminary sizing of UO works components was based on hydraulic network
analyses of proposed CMWD recycled water distribution system expansions,
which are represented in the recently completed Enciizu Basin Recycled Wurer
Disrributioiz System Study. Although volumes associated with Mahr Reservoir's
operational storage function are relatively small compared with those of seasonal
storage, operational storage peak-hour hydraulic requirements should be used to
size YO piping and valves. Table 4-1 lists peak-hour withdrawal rates estimated
in the above-noted work for the Phase 11 and ultimate system expansions. As
additional recycled water production capacity and operational. storage volumes
elsewhere are ultimately developed, the peak-hour demand on Mahr Reservoir's
storage decreases from Phase I1 to the ultimate condition. Hence, the estimated
CGvL ENGINEERS IN ASSOClATION WITH JOHN POWELL & ASSOCIATES 4-2
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Facilitv Alternatives
Parameter
Peak-Hour Flow
Phase II peak-hour withdrawal rate is higher than the ultimate rate, and the Phase .
IT rate should be used for YO works sizing.
Milestone
Units’ Phase €I Ultimate
em 7,947 6,473
Because the runs are short, the existing 18-inch VO pipeline, which lies under the
dam, and proposed extension up the dam face should be considered as distribution
pipelines for sizing. As shown in Table 4-1, peak-hour velocities in the existing
18-inch YO pipeline will exceed normal hydraulic design criteria discussed in
Chapter 2. This situation would improve from Phase II to the ultimate condition.
The higher velocities could be tolerated in the existing piping, since its
replacement or paralleling would be extremely difficult, but the proposed
extension to the works should use 24-inch piping, the nearest regular pipe size
satisfying hydraulic design criteria.
Based on Existing UO Pipelbe Diameter (18 inches)b:
Based on Hydraulic Criteria Diameter (24 inches)b:
Pipe Velocity I fPS
Pipe Velocity fps
10.6 8.6
5.6 4.6
Because the total headloss difference between a 24-inch and 18-inch valve is
relatively small, and the cost difference relatively larger, 18-inch valves are
assumed for the four proposed new I/O port controls. Each YO port would be
protected from coarse suspended material by appropriate stainless steel screens.
The arrangement of these screens is highlighted on Figure 4-2, and a photo,graph
of similar I/O port screens at SMWD’s Upper Os0 Reservoir is shown on Figure
4-3. All valves would be hydraulically operated with control lines terminating in
a proposed operations building at the reservoir’s north side, as shown on Figure
4-1. A probable cost opinion of the modified I/O works is given in Table 4-2.
I AeratiodDestratification Svstem. A body of water like Mahr Reservoir, several
feet deep or more, will naturally tend to undergo thermal stratification. Because
of solar heat load, upper and lower waters tend to become thermodynamically
“separate” with respect to uniform mixing. Upper waters tend to stay well mixed
and aerobic, while lower waters become stagnant and anoxic. The latter
environment, especially with chemicals present in recycled water, can promote
hydrogen sulfide and other odiferous chemical production. With CMwD’s
climate, one stratification cycle per year will occur, with onset in spring, greatest
stratification in late summer, natural mixing or “turnover” in fall, and well-mixed
water in winter.
J
I
CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL&’ASSOCIATES 4-5
Facility Alternatives
Upper two I/O ports, looking east.
Figure 4-3 Upper Os0 Reservoir I/O Works
An aeration system can perform substantial mixing of the reservoir volume and
provide supplemental oxygen. This mixing can prevent or eliminate stratification,
and its undesirable consequences, and even help control certain algae growth.
Typical Southern California experience shows the system only needs to operate
part of the day or a few days a week, and only during the spring-to-fall half of the
year.
A common system configuration, used in several reservoirs and lakes in San
Diego and Orange Counties. includes an air compressor. usually housed in a small
building for protection and sound attenuation; an air supply pipeline; and a
diffuser pipeline. usually located 5-10 feet above the bottom near the deepest
portion of the basin. Keeping this diffuser pipeline well submerged is one reason
to establish a 12.5-foot deep minimum operating pool, discussed in Chapter 1.
The operations building noted above could house both the 1/0 works valve
controls and the aerationldestratification system's compressor. Location of these
features is shown on Figure 4-1. A photograph of the proposed operations
building site is provided as Figure 4-4.
.. . ..
CG\'L ENGINEERS K ASSOCl.4TiOS WITH JOHN PO\V€LL & ASSOC'l:\TES 4-6
Facility Alternatives
Item
Demolition Work
Concrete Vault
Excavation I
Backfill
Concrete
Shoring
24-Inch Steel Pipe wEpoxy Coating
Welding Joints
18x18x18-inch Tee wEpoxy Coating 18-inch 90-degree Elbows w/Epoxy
24x1 8-inch Reducer w/Epoxy Coating
24x24x18-inch Tee wEpoxy Coating
Flexible Coupling
18-inch BFV w/ Hydraulic Cylinder
Stainless Steel Wire Screen
Hydraulic Accumulator System
Pipe Support
Miscellaneous Metalwork
Coating
Qur
No.
1
33
16
10
5
140
30
5
.i
1
4
2
5
4
1
20
1
Flprtriralnnntrumentation I1 -.__-_________
Sales Tax on Material Cost, 7.75 percent
Mobilization & Demobilization, 3 percent
Subtotal Construction
itity
Unit' Ls
CY
CY
CY
ton
ft
each
each
each
each
each
each
' each
each '
each
each
LS LS
Contractor OH&P 20 percent
Total Construction Contingency 20 percent
Subtotal Project
a) b) Cost for January 2000.
Unit abbreviations: LS = lump sum; CY = cubic yard.
Material Cost
dollars
115
315
900
950
680
1,730
. 500'
5,000
3,500
32.000
16,100
9,450
4,500
950
680
6,920
1 ,000 25,000 .
14,000
32,000
3,:; I ;%
12,000 12.000
Labor Cost
dol
Unit
20,000
20
20
400
360
105'.
33
'982
769
763
1,126
* 650
2,500
1500.
41,000
500
1.558
5,900
Total
20.000
660
320
4,ooi)
J4.700
1.800
990
4,910
769
763
4504
1,300
12500
6,000
41,000
1o.m
1558
5.900
rotal cost
dollarsb
20,000
1.980
960
.6,000
4,800
30,800
10,440
9,410
1,719
, 1,443
11.424
2,300
37500,
20,000
73.000
15,000
5 ,OS 8
17.900
10,700
8,092
288,526
57,705
346,231
69246
415,477
62,322
477,799
CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCWTES 4-1
Facility Alternatives
Wide spot in access road. looking east over spillway.
Figure 1-1 Proposed Mahr Reservoir Operations Building Site
For durability and flexibility. the air supply and diffuser pipelines are assumed
constructed of 4-inch diameter polyethylene piping. The diffuser pipeline would
have small. appropriately-sized holes drilled approximately every five feet for its
entire length. This pipeline would be held in place. approximately parallel to the
reservoir bottom. by a series of anchors that resist the pipeline's tendencv to rise
when charged with air. This type system has been operating at SMWD'; Upper
Os0 Reservoir for approximately ten years. While other aeration/destratification
systems are feasible, a probable cost opinion for the one described here, with
costs adjusted from SMWD's experience. is presented in Chapter 5.
Outflow Chlorination. Open seasonal storage generally degrades bacteriological
water quality below those levels specified by Title 22. California Code of
Regulations. for disinfected tertiary effluent at a treatment plant production
source. The extent of degradation depends on the size of the drainage area
tributary to the reservoir and the development characteristics of the drainage area.
While not currently required by regulatory agencies, chlorination of reservoir
outflow could be done to mitigate this degradation. Because of no regulatory
requirement for outflow disinfection, the very small Mahr Reservoir tributary
watershed area. and no predominant outflow chlorination practice elsewhere
-
CGvL ENGWEERS M .ASSOCIATION WITH JOHN POWELL & ASSOCIATES 4-8
Facility Alternatives
specifically for disinfection, this candidate improvement is not considered further.
It could be reconsidered for a future phase of work.
I
Outflow Microscreening. Reusing the existing fine screens could provide some
control of water quality, although distribution system algae problems still
occurred during the original deployment. Such reuse wduld involve
improvements in situ at the Meadowlark WRF or equipment relocation to the Mahr Reservoir site. Some WRF process and related modifications could be
required.
A significant drawback to outflow microscreening is the need to break head.
Mitigating this hydraulic disruption would require pumping designed for peak-
hour flow rate and complex pump controls. In light of these disadvantages, and
the years of several major recycled water storage reservoirs (see Chapter 1)
operating successfully without such treatment, this candidate improvement is not
considered further.
If the need emerges to remove particulate matter in reservoir outflow beyond that
removal 'accomplished by the proposed I/O port screens, large and relatively
inexpensive strainers of the type used by SMWD for Upper Os0 Reservoir could
be deployed. These could be installed in-line, with no head break, on the existing
18-inch YO line near where it emerges from the downstream dam toe. In normal
operation such strainers involve a typical headloss of only a few pounds per
square inch.
.
Reservoir Lining and Covering: Lining and covering a reservoir can control
algae growth and other water parameters. Two lining and covering alternatives
were considered candidates for Mahr Reservoir:
o Alternative A - a floating cover with a geo-membrane liner
o Alternative B - a floating cover with a porous asphaltic-cement (AC) liner
The geometric configuration of the existing reservoir was reviewed for
compatibility with the two commonly used systems for maintaining tension on a
floating cover: weight-tensioning and mechanical-tensioning. Weight-tensioned
floating covers are distinguished by a series of strategically located trough
weights and floats attached to the floating cover to take up excess material and
keep the floating cover taut. These trough weights create a fold where excess
material accumulates and that also serves as a rainwater collection trough. Rain
falling on the floating cover migrates into the troughs and is removed by a
rainwater removal system, consisting of pumps or gravity drain assemblies.
With mechanically-tensioned floating covers, cables are attached to the floating
cover and connected to a counter-weight and pulley system to maintain floating
cover tension. The counterweights are housed in a number of small individual
towers surrounding the reservoir perimeter. The rainwater removal system
~ CGvL ENGJNEERS Dl ASSOClATlON WlTH JOHN POWELL & ASSOCMES 4-9
..
Facility Alternatives
typically consists of pumps or gravity drains placed on the floating cover to
remove surface water. .
Both these cover systems have very similar estimated unit costs. The reservoir
site can be reconfigured to suit either cover system; however, the mechanically-
tensioned cover system would only be practical if the operating water level of the
reservoir was restricted to the upper 15 feet of its range. A weight-tensioned
cover system would allow the full operating range in the existing reservoir to be
used. Therefore, for this evaluation, a weight-tensioned cover system, with 45-
mil polypropylene cover material and full perimeter sump, is considered for
budget pricing of both lining and covering alternatives.
Recommended impermeable geo-membrane liners for this application include a
45-mil polypropylene liner or a 60- to 90-mil high-density polyethylene OPE)
liner. HDPE liners are cheaper, but have a higher coefficient of thermal
expansion, making installation and maintenance more complicated. For this
evaluation, the 45-mil polypropylene liner is considered for budget pricing for
Alternative A.
It is anticipated that the addition of an impermeable geo-membrane would require
careful review by a geotechnical engineer and DSOD. Key items for . '
consideration by DSOD would be potential loss of soil moisture in the dam
embankment, under-drain piping and under-drain relief piping. The loss of
moisture in the dam embankment could be significant as the dam core appears to
be constructed with clay, based on available record drawings. It is likely the
under-drain relief piping could require penetrating the dam embankment to
discharge under-drain flows.
Other items that are typically part of an existing reservoir retrofit with a floating
cover and a geo-membrane liner include:
3 A means to anchor the edge of the liner
o Appurtenances such as vents, access hatches, and inflation ports
o A rainwater relief system
A probable construction cost opinion for adding a floating cover and geo-
membrane liner to Mahr Reservoir is shown in Table 4-3. The costs for the basic
appurtenances described above are included in the unit cost for the cover and are
based on past experience with similar projects,
As described above, it is anticipated that a geo-membrane liner system may not be
compatible with the existing dam embankment and would require considerable
review by DSOD. Therefore, porous AC liner system, Afternative B, was
reviewed as another method for lining the reservoir. This type of liner system
would not require an under-drain system and under-drain relief piping. This
alternative would likely reduce requirements for DSOD permitting.
CGvL ENGINEERS Ih' ASSOCIATION WITH JOHN POWELL & ASSOCIATES 4-10
Facility Alternatives
Item'
Porous AC Liner Polypropylene Liner
Underdrain (in reservoir) Underdrain (through embankment)
Baseb
Polypropylene Cover & Appurtenances'
Concrete Ringwall Appurtenances
, Excavationd
Subtotal Construction
Contractor OH&P
Total Construction Contingency
Subtotal Project
Alternative A
NIA
385,000
40,000
20,000
86,625
735,000
I 116,000 I
I'
Alternative B
385,000
NIA
NIA
NIA
86,623
735,000 116,000
Ouantitve I Uhit Cost
1
385,000 I $llSF
Ls 100,OOO 100,OOO
1,482,625 1,422,625
385,000
1,600
500
115,500
350,000
2,900
296,525
1,779,150
355,830
2,134,980
$l/SF
$25/LF . $40m
$0.75/SF
$2.101SF WOLF
2843 25
1,707,150 341,430
2,048,380
Engineering & Administration
Total Project
15 percent 320,247 307,287
2,455,227 2355,867
20 percent
20 percent
a)
b)
C)
d)
e)
f) Cost for January 20oO.
This estimate only includes costs for work associated with the liner and cover. Costs for inlet and outlet
structures, minor concrete, and other miscellaneous work have not been included.
Base quantity assumes a bottom area with 6" thick decomposed granite base. Type and cost of base may change
based on a detailed geotechnical evaluation. Appurtenances include vents, access hatches, inflation ports, and rainwater relief system.
Excavation cost may change based on actual site conditions and method of excavation.
Volume = 160 AF, surface area = 350.000 square feet (SF), bottom area = 385,000 SF. perimeter = 2,900 linear
feet.
A probable cost opinion for adding a floating cover with a porous AC liner to
Mahr Reservoir is also shown in Table 4-3. The cost for basic appurtenances
described above are also included in the unit cost for the cover. These costs are
based on past experience with similar projects and accepted cost references.
In order to install either alternative lining and covering system, the existing
reservoir would require draining, debris/sludge removal, dewatering and remedial
grading to reconfigure the side slopes and reservoir bottom. Prior to liner system
installation, base material would be placed as recommended by a geotechnical
engineer. For the purposes of this evaluation, allowances have been made for
excavation and installation of base material, based on similar projects. *
Operation and maintenance costs for a floating cover and liner system depend
somewhat on liner alternative. These can be estimated if a decision is made to
, pursue either lining and cover alternative further.
As shown in Table 4-3, Alternatives A and B have comparable costs; however,
Alternative B would not require a possible change to the design intent of the dam
embankment nor would it require a piping penetration through the embankment
for under-drain relief. For these reasons, it is believed that the Alternative B
CGvL ENGINEERS n\r ASSOCIATION WITH JOHN POWELL & AssoCMTEs 4-1 1
Facility Alternatives
.. would be easier to design, permit and maintain. Based on results of this
evaluation, the floating cover with a porous AC liner is considered further in
Chapter 5.
Miscellaneous Site Work. Other more minor site improvements may be required
in addition to the major ones previously discussed. These items could include
improving site access roadways, adding selective landscape treatment, and
installing a protective surface on the upstream dam face. The latter could be
accomplished with AC pavement, which would mitigate erosion as’ well as
decrease “foothold” for rooted aquatic vegetation. A lump cost opinion is
provided for these items in Chapter 5.
Alternative Combinations of Improvements
Two types of facility alternatives are defined: using or not using Mahr Reservoir
in the planned recycled water system; and, if the decision is to use Mahr
Reservoir, selecting the best combination of facility improvements. To make a
fair comparison when Mahr Reservoir is not to be used, equivalent seasonal,
operational, and emergency supply components must be considered. These could
include additional peak-month supply capacity and an above-ground operational
storage reservoir, respectively. These alternatives and cost opinions thereof are
discussed in Chapter 5.
The long-term history of other recycled water seasonal storage reservoirs,
discussed in Chapter 1, argues strongly against the need for a lining and covering
system at Mahr Reservoir. Given that and the relatively large cost of lining and
covering systems, two combinations of improvements are considered. The first
combination involves the following improvements:
CI Dredging and cleaning the reservoir bottom
o Modifying the YO works
o Adding an aeratioddestratification system
o Performing miscellaneous site work.
, ..
The second combination involves all the above plus adding lining and covering.
Since Mahr Reservoir has a very small tributary watershed area, the first
combination of improvements should provide adequate water quality. Dredging
and cleaning, and use of aeratioddestratification will tend to maintain an aerobic
environment throughout the reservoir water column throughout the year. This
will tend to eliminate hydrogen sulfide production and other unpleasant odors.
Multiple ports in a modified I/O works will tend to allow best quality water
stratum selection. Since algae grow largely near the reservoir water surface, this
will tend to greatly minimize the likelihood of algae being moved into the
distribution system.
CGvL ENGINEERS IN ASSoClATlON WITH JOHN POWELL Sr ASSOC~ATES 4-12
Facility Alternatives
An additional reason, besides cost, exists for deferring further consideration for
reservoir lining and covering. In 1997 the State Department of Health Services
published a comprehensive evaluation of reservoir lining and covering systems.
Their primary focus was a sanitary assessment with respect to potable water
storage and quality. However, they noted some generic concerns that would be
relevant to application with high-quality recycled water as planned by CMWD:
o Cover materials are “vulnerable to puncture” and “slashes,” as from
vandalism, and cover seams are “potential weak spots that can compromise
the watertight integrity”
o Drainage systems used to remove accumulated rainwater are “not reliable”
o Many of the agencies that have installed lining and covering systems “have
attempted to establish.. . a (maintenance) program but found this process to be
exceedingly difficult, labor intensive, and expensive.”
CGvL ENGINEERS N ASSOCLATION WITH JOHN POWELL & ASSOCIATES 4-13
Mahr Reservoir Use Benefits
Mahr Reservoir can provide seasonal, operational (diurnal), and emergency
storage to CMWD’ s recycled water production and distribution system. Seasonal
and emergency storage benefits are quantified in Chapter 3. Absent Mahr
Reservoir, CMWD’s system would need equivalent peak-month supply capacity.
This would require, for comparative analysis, a marginal increase in peak-month
supply from the Carlsbad AWT facility, according to the flow rates given in Table
3-3.
From an operational storage perspective, Mahr Reservoir is favorably located
geographically and topographically. It provides a storage volume well suited to
service demand along Rancho Santa Fe Road, both north and south of the
reservoir site, and it could back-feed flow into the lower distribution system
pressure zone. The reservoir is also at a key elevation for establishing the
hydraulic grade line in the nearby portion of the distribution system. Absent
Mahr Reservoir, the system would need equivalent operational storage capacity.
This would require, for comparative analysis, an alternative 1.5-MG reservoir at a
site in the vicinity near elevation 550 feet.
From an emergency storage perspective, Mahr Reservoir’s volume could offset a
loss of supply at one of the regular production sources for a given period of time.
The appropriate volume would vary depending on total system production
capacity available, demand on the distribution system, volume of water in the
reservoir, and time of year. For example, if a supply outage occurred in the peak
demand month, the volume withdrawn for emergency supply offset would
, directly eliminate a corresponding volume of peak-month seasonal storage.
Emergency storage remains a benefit for Mahr Reservoir, but it is difficult to
quantify monetarily. Sample volumetric approximations are given at the end of
Chapter 3.
1
Another possible benefit of Mahr Reservoir relates to ocean outfall capacity.
During the winter, Encina WPCF may incur hydraulic limitations in peak wet-
weather treated wastewater disposal capacity. Water reclamation, via the
CGvL ENGINEERS IN ASSOCMTION WITH JOHN POWELL & AssocuTEs 5- 1
Alternative Costs and Phasing
proposed Carlsbad AWT. facility, could remove some flow from the disposal
stream. Because of low winter demand, such excess recycled water would have
to be stored. However, according to the analyses included in Appendix B, even in
the current condition, Mahr Reservoir’s volume is relatively small and would not
necessarily take enough flow in the winter to save significant treated wastewater
disposal capacity in the Ocean outfall system. Appropriate estimations of realistic
volumes wduld require more detailed modeling of Encina WPCF and are beyond
this evaluation’s scope. Therefore, no benefit is quantified for this function.
Comparative Improvement Costs
For Phase II cost comparison, Alternative 1 includes use of Mahr Reservoir and
all the facility improvements summarized at the end of Chapter 4. Alternative 2
replaces Mahr Reservoir with an equivalent new 1 .S-MG, above-ground, steel,
operational storage reservoir on a new1 y-purchased site; and 1.46-MGD additional
peak-month equivalent supply capacity (see Table 3-3), assumed as a marginal
increase to planned Carlsbad AW expansion capacity. Table 5-1 shows
resulting capital costs by line item and totals.
CGvL ENGINEERS o\I ASSOCIATION WITH JOHN POWELL 8: ASSOCIATES 5-2
...
Alternative Costs and Phasing
Item
With Mahr Reservoir
Dredging & Cleaning"
Modified YO Works"
AerationDestratification System"
Lining and Coveringb
Quantity
1
1
1
160 AF
Miscellaneous site worka 1
Without Mahr Reservoir
New Oper. Storage Res. Sitea
New Oper. Storage Res. Construction'
1 acre
1.5 MG
Additickal Peak-Month Plant Capacityd 1.46 MGC
Subtotal Construction
Contractor OH&P
Total Construction
Contingency
Subtotal Project
20 percenl
20 percenr
Engineering & Administration 15 percenl
a) Preliminary estimate.
b) Cost based on lining and covering Alternative B.
c) Volume sized per final distribution system analysis.
Total Project
Unit Cost
lump sum
lump sum
lump sum
lump sum
lump sum
lump sum
4 13,000
1 167,000
Total Co
~ternative I'
1 so,o00.
289,000
166,000
1,423 ,OOO
175,000
NIA
NIA
N/A
2,203,000
441,OOO
. 2,644,000
529,000
3,173,000
476,000
3,649,000
dollad
Uternative Zg
NIA
NIA
NIA
NIA
NIA
100,OOO
620,000
1,704,000
2,424,000
485,000
I 2,909,000
582,000
3,491,000
524,000
4,015,000
Capacity based on Chapter 3 analysis, shown in Table 3-3; cost based on incremental capital improvements in
preliminav Design Repolt for the Carlsbad Water Recycling Facility.
Cost for January 2000; assumes remainder of recycled water supply and distribution costs for a total Phase I1 system
at 5,400 AFY is the same for both alternatives.
f) Assumes Mahr Reservoir improved for use as operational and seasonal storage.
g) Assumes equivalent operational storage and peak-month supply capacity obtained without Mahr Reservoir. I
At this estimating level, Alternative 1's total project cost is slightly less than
Alternative 2's total project cost. Alternative 2's total project cost would change
a small amount if a different capacity operational storage reservoir were used and
if a different plant capacity were chosen. More significantly, Alternative 2's total
project cost would increase for the ultimate condition, while Alternative 1's total
project cost would not. In that condition, an estimated 3.5 MG of alternative
operational storage and a total additional peak-month plant capacity of I .62 MGD
(see Table 3-3) would be needed, which would increase Alternative 2's total
project cost by approximately $1,842,000, as shown in Table 5-2. Considering
these additional costs to Alternative 2 and the monetarily unquantified emergency
storage benefit of Alternative 1, Alternative 1 appears the least-cost capital
option.
Alternative Costs and Phasing
Contingency
Subtotal Project
- Engineering & Administration
Total Project
20 percent 529,000 849,000
. 3,173,000 5,093,000 15 percent 476,000 764,000
3,649,000 5 , 857 , 000
Preliminary estimate.
Volume estimated from ratio of ultimate to Phase II demands.
Capacity based on Chapter 3 analysis, shown in Table 3-3; cost based on incremental capital improvements in
Preliminary Design Report for the Carlsbad Water Recycling Facility. Cost for January 2000; assumes remainder of recycled water supply and distribution costs for a total ultimate system
at 9,800 AFY is the same for both alternatives.
Assumes Mahr Reservoir improved for use as operational and seasonal storage.
Assumes equivalent operational storage and peak-month supply capacity obtained without Mahr Reservoir.
Operating costs for Mahr Reservoir would be relatively minor, and probably
comparable to those associated with Alternative 2. They are not considered
herein because they would not be expected to affect the decision.
Improvement Phasing
If lining and covering were deleted from Alternative 1, the resulting total cost
would be substantially less than the .cost for any version of Alternative 2.
Alternative 1 could be phased, with initial Mahr Reservoir improvements for
Phase II including all items except lining and covering, which would be deferred
as discussed in Chapter 4. These Phase II reservoir improvements could be tested
for several years before reconsidering the need for additional reservoir
improvements. If lining and covering were needed, it could be constructed as part
of a Phase III system expansion. Based on Table 5-1, the total project cost
opinion for initial reservoir improvements under Alternative 1 is shown in Table
5-3.
CGvL ENGINEERS IN ASSOCLATION WITH JOHN POWELL & ASSOCLA~ 5 -4
Alternative Costs and Phasing
I tern
Dredging & Cleaning
Modified VO Works
AeratiodDestratification System
Miscellaneous Site Work
Subtotal Construction
Contractor OH&P
Total Construction
Contingency
Subtotal Project
Engineering & Administration
' Total Project
Quantity
1
1
1
1
20 percent
20 percent
15 percent
a) All entry notes same as for Table 5-1.
Unit Cost dollars
lump sum 150,OOO
lump sum 289,000
lump sum 175,OOO
780,000
156,000
936,000
187,OOO
1,123,000
168,000
1,291,000
lump sum 166,OOO
. .. .
.. I
CGvL ENGINEERS IN ASSOC~ATION WlTH JOHN POWELL & ASSOCIATES 5-5
Facilities
In light of the foregoing evaluation and related ongoing preliminary design of
CMWD’s recycled water distribution system, the following recommendations are
made to CMWD regarding Mahr Reservoir:
o Proceed with acquisition of rights from VWD to improve and use the reservoir
on a long-term basis
o Phase reservoir improvements as delineated in Chapter 5, with further
consideration for a liner and cover deferred to system expansion Phase III
o Design and construct all initial reservoir improvements in parallel with other
Phase II system expansion improvements
o Once the improved reservoir is placed in service, test its performance for
several years before reconsidering the need for additional improvements.
Monitoring Program
To properly test performance of an improved Mahr Reservoir, an adequate
monitoring program will need to be initiated. Such a program typically requires
use of a boat for sample acquisition and use of a portable analyzer to measure
cornon limnetic parameters at different depths. Table 6-1 illustrates a typical
program, with samples collected in the water column between the existing
reservoir YO works and the upstream dam toe. Daily sample timing would
depend on operating times of the proposed aeratioddestratification system and
any specific regulatory requirements.
Parameter
Dissolved Oxygen
Temperature
Electrical Conductivity
Oxidation-Reduction Potential
PH
Turbidi ty
Coliform
General Mineral
Method
Analyzer
Analyzer
Analyzer
Analyzer
Analyzer
Analyzer
Grab
Depth
Every 5 feet
Every 5 feet
Every 5 feet
Every 5 feet
Every 5 feet
Every 5 feet
TOP Grab I Top and Bottom
Frequency
Monthly
Monthly
Monthly
Monthly
Monthly
Monthly
Monthly
Quarterly
CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES 6- 1
Recommendations
At the program’s onset, similar samples could be collected at a few other
locations around the reservoir, to verify that the recommended sample location is
adequately representative of the entire water body.
CGvL ENGINEERS LN ASSOCIATION WITH JOHN POWELL & ASSOCIATES 6-2
Appendix A
HISTORICAL RECYCLED WATER DEMANDS
CGvL ENGINEERS IN ASSOClATlON WITH JOHN POWELL & ASSOCIATES A- 1
PI 9 .I
i 0 >
Appendix B
SEASONAL STORAGE MODEL RUNS
CGVL ENGtNEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES B- 1
Analysis of Monthly SupplyDernandEtorage Requirements
Evapo- Seasonal
transpir., Precip., Variation
Month in in Ratio
Jan n/a nla 0.1 1
Feb n/a n/a 0.1 6
' Mar n/a n/a 0.37
May n/a n/a 1.37 Apr
Jul nla nla 2.1 0
SeP n/a n/a . 1.51
Nov n/a n/a 0.42
Dec n/a nla 0.46
n/a n/a 0.82
Jun n/a n/a 1.83
Aug n/a n/a 1.76
oct n/a n/a 1.09
-------,-----I---I-------------------------------------------------------
Project Other Total RW Other Total
Demand, Demand, Demand, Supply, supply, supply,
aC-ftC ac-it ac-tt ac-ftO ac-ft e ac-ft
16 0 16 150 0 150
24 0 24 1 50 0 150
56 0 56 1 50 0 150
123 0 123 150 0 150
205 0 205 150 0 150
275 0 275 1 50 0 1 50
31 5 0 31 5 150 0 150
264 0 264 1 50 0 1 50
226 0 226 150 0 1 SO
163 0 163 1 50 0 1 50
63 0 63 1 50 0 1 50
70 0 70 150 0 150 ________-_____________
Reser. Reser. Unused
Flow, Storage, RW Supp.
ac-ft ' ac-ftP ac-tt
TOTAL n/a n/a 12.00 1,800 0 1,800
302
427
521
548
493
368
203
89
13
0
87
168
1.800 0 1,800 0 946
79
79
79
79
79
79
79
79
79
79
79
79
Monthly Reservoir I Unused RW Supply I
I I/ 600
- INPUT
da = effedlve/total precipitation ratio (no units) n/a = irrigation efficiency (no units) 1,800 = annual project irrigation demand (ac-fUyr)
a) b) c) d) e)
f)
2.45 = maximum recycled water supply available (mgd:
0.00 = maximum other water supply available (mgd: 3.00 = maximum reservoir inflow allowed (mgd)
3.00 = maximum reservoir outflow allowed (mgd)
g) 1,000 = maximum reservoir working storage available (ac-It)
Monthly Supply I Demand
350- i n -I ~0~~~~
Jan Feb Mar Apr May Jun Jul Aug Sep OU NOv Dec
Month
i
OUTPUT
2.10 = peak month factor (no units) nla = irrigation application ate (fVyr) '
1.800 = annual total demand (ac-Wyr)
1 .OO = total supply/demand ratio (no units: Jul E maximum irrigation demand month Jan = minimum irrigation demand month
1.61 = maximum RW supply used (rngd)
0.00 = maximum other supply used (mgd) 1.43 = maximum reservoir inflow used (mgd)' 1.77 = maximum reservoir oumoW used (mgd)
548 = maximum reservoir working storage used (ac-ti)
100
I Jan Fea Mar Apr May Jun JuI Aug Sep On NOW Dec
Month
I
F:\Proiects\Powell.ZO~a~s~d Ph II.M)l\ResewoiARevMSDS ~ 1 A-Currenl 5/31/00
Analysis of Monthly Supply/Demand/Storage Requirements
donth
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
Sep oct
Nov
Dec
TOTAL
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 1 B: With No Seasonal Storage SUPPLY: RW=2.45 mgd; Other=0.92 rngd
QEMAND: Current Q 1,800 ac-ft&r
TORAGE: 0 ac-ft existing seasonal storage, 0 ac-R required seasonal storage
Evapo- Seasonal
transpir., Precip., Variation
in in Ratio
n/a nla 0.1 1 n/a n/a 0.16
nla n/a 0.37
nla n/a 0.82
1.37 n/a n/a n/a da 1.83
nla n/a 2.1 0
n/a n/a 1.76
nla nla 1.51
n/a da 1 .El
n/a n/a .0.42 n/a n/a 0.46
da n/a 12.00
_----------------I-----
Project Other Total
Demand, Demand, Demand,
ac-ft ac-ft ac-ft
~~ ~~
16 0 16
' 24 0 24
56 0 56
1 23 0 1 23
205 0 205
275 0 275
315 0 315
264 0 264
226 0 226
1 63 0 163
63 0 63
70 . 0 70
1.800 0 1.800
.-_----I-__--_-----------------
- INPUT
nla = effectivehotal precipitation ratio (no units) nla = irrigation efficiency (no units) 1.800 = annual project irTigation demand (ac-Wyr) 2.45 = maximum recyded water supply available (mgd:
1.00 = maximum other water supply available (mgd: 0.00 I maximurn'reservoir inflow allowed (rngd)
0.00 = maximum reservoir outllow allowed .(mgd)
a)
b) c) d) e)
f)
9) 0 = maximum resewoir working storage available (ac-fl)
Monthly Supply I Demand
350
300
250
200
150
100
50
0 I Jan Fcb Mar Apr May Juri Jul Aug Sep oct NOv Dec I I Month
RW Other Total
ac-ft a ac-ft ac-ft
SUPPlY, Supply, Supply,
~
16 0 16
24 0 24
56 0 56
1 23 0 123
205 0 205
229 46 275
229 86 31 5
229 35 264
226 0 226
163 0 163
63 0 63
70 0 70
1,633 167 1,800
---1--*---1-- ---_--
Reser. Reser. Unused
Flow, Storage, RW Supp.
ac-ft' ac-ftP x-ft
0
0
0
0
0
0
0
0
0
0
0
(0)
0 21 3
0 204
0 173
0 105
0 24
0 0
(0) 0
(0) '0
(0) 3
0 65
0 166
0 159
(0) 1,113
OUTPUT
2.10 = peak month factor (no units) n/a = irrigation application rate (tvyr)
1.800 = Bnnual total demand (ac-ftlyr)
1 .OO = total supply/demand ratio (no units:
Jul = maximum irrigation demand month Jan = minimum irrigation demand month
2.45 = maximum RW supply used (rngd) 0.92 = maximurn other supply used (mgd) 0.00 = maximum reservoir inflow used (mgd)
0.00 = maximum reservoir outflow used (mgd) 0 = maximum reservoir working storage used (ac-ft)
I I
!
i I
Monthly Reservoir I Unused RW Supply I
2%
Jan Feb Mar Apr May Jun Jul Aug Sep On NW Dee
Month I i
F:\Projects\Povell.ZOT\Carlsbad Ph 11.001\ReservoiARevMoSDS ~ 1 BCurrenc 5/31/00
Analysis of Monthly Supply/Demand/Storage Requirements
Project Other Total
Demand, Demand, Demand,
ac-ft ' ac-ft ac-ft
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 1C: With Mahr Reservoir Seasonal Storage
SUPPLY: RW-2.45 mgd; Other=O.l7 mgd
qEMAND: Current d 1,800 ac-fylr
TORAGE: 0 ac-ft existing seasonal storage, 151 ac-ft required seasonal storage
RW Other Total
Supply, Supply, Supply, ac-ftm ac-ft ' ac-ft nonth
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
Sep oct
Nov
Dec
TOTAL
-
__I - -
~
16 0 16
' 24 0 24
56 0 56
123 0 123
205 0 205
275 0 275
31 5 0 31 5
264 0 264
226 0 226
163 0 163
63 0 63
70 0 70
1,800 0 1,800
_---_---------I----------------
Evapo- Seasona
ranspir., Precip., Variatior
in in Ratio
da nla 0.1 1
nla nla 0.1 6
n/a n/a 0.37
n/a n/a 0.82
da da 1.37
da nla 1.83
nla n/a 2.1 0
rda nla I .76
n/a n/a 1.51
da n/a 1.09
n/a nla ,0.42
n/a nla 12.00
n/a n/a 0.46 .--------------------
92 0 92
100 0 100
56 0 56
123 0 1 23
205 0 205
229 0 229
229 16 245
229 0 229
226 0 226
163 0 163
63 0 63
70 0 70
1,784 16 1,800
-I----
INPUT
nla = effectivehotal precipitation ratio (no units) nla = irrigation efficiency (no units) 1,800 = annual prqecl irrigation demand (ac-Wyr)
2.45 = maximum recycled water supply available (mgd: 0.00 = maximum other water supply available (mgd: 3.00 = maximum reservoir inflow ,allowed (mgd) 3.00 = maximum reservoir outflow allowed (rngdl 151 = maximum reservoir working storage available (ac-It)
a) b) c) d) e) f)
f I
Monthly Supply I Demand
350 7
n 300- I I i
Jan Fcb Mar Apr May Jun Jul Aug Sep o* NW D~c I Month 1
Reser. Reser. Unused
Flow, Storage, RW Supp.,
ac-ft ' ac-ft ac-tt
76 76 1 37
76 151 129
0 151 173
0 151 105
0 151 24
(46) 105 0 cm) 35 0
(35) 0 0
0 0 3
0 0 65
0 0 166
159 0 0
(0) 962
--- ------
OUTPUT
1) 2.10 = peak month factor.(no units)
2) 3) 1,800 = annual total demand (ac-Wyr)
4) 1 .OO = total supply/demand ratio (no units; 5) Jul = maximum irrigation demand month
6) Jan = minimum irrigation demand month
7) 2.45 = maximum RW supply used (mgd)
8) 0.17 = maximum other supply used (mgd)
91 0.81 = maximum reservoir inflow used (mgd)
10) 11) 151 = maximum reservoir working storage used (ac-t)
n/a = irrigation application rate (Wyr)
0.75 = maximum reservoir outflow used (mgd]
I 1 II Monthly Reservoir I Unused RW Supply .
1 I" 200
180
1 K-
14
120
100
BO
60
40
20
0 I Jan Feb Mar Apr May Jun Jul Aug 5ep On Now Dec
Month !
F:\PrciecIs\Powell.ZOACarlrbad Ph Il.Wl\Resewoir\RevMoSDS. lC-Curfenl
Evapo- Seasonal
transpir., Precip., Variation
Month in in Ratio
Jan nla n/a 0.1 1
Feb nla n/a 0.1 6
Mar n/a n/a 0.37
n/a n/a 0.82 - May n/a n/a 1.37
Jun nla nla 1 .83
Jul nla nla 2.1 0
Aug n/a n/a 1.76
oct n/a n/a 1.09
Nov nla nla 0.42
Dec n/a n/a 0.46
TOTAL n/a n/a 12.00
Apr
SeP n/a n/a 1.51
INPUT
n/a = effectivehotal precipilalion ratio (no units) n/a I irrigation efficiency (no units) 5.400 = annual project irrigation demand (ac-Wyr)
8.00 = maximum recycled water supply available (mgd:
0.00 = maximum other water supply available (mgd:
8.00 I maximum reservoir inflow allowed (mgd)
8.00 = maximum reservoir oulflow allowed (mgd)
a) b)
d) e)
f)
c)
Q) 2,000 = maximum reservoir working storage available (ac-It) D
Other Total Reser. Reser. Unused Project Other Total RW
Demand, Demand, Demand, Supply, SUPPIS., Supply, Flow, Storage, RW Supp.,
ac-ftc ac-ft ac-n ac-ft" ac-ft ac-ft ac-tt' ac-tto ac-R
49 0 . 49 450 0 450 401 905 297
73 0 73 450 0 450 3n 1282 297
168 0 168 450 0 450 282 1.564 297
370 0 370 450 0 450 80 1,644 297
61 5 0 61 5 450 0 450 (165) 1,479 297
824 0 824 450 0 450 (374) 1,104 297
945 0 34s 450 0 450 (495) 609 297
791 0 791 450 0 450 (341) 268 297
490 0 490 450 0 450 (40) 0 297
1 88 0 188 450 0 450 262 262 297 209 0 209 450 0 450 241 503 297
5,400 0 5.400 5,400 0 5,400 (0) 3,565
678 0 678 450 0 450 (228) 40 297
____-._-_-__-I---------------------------~---------_---_----------_______I_______I__ -
OUTPUT
2.10 = peak month factor (no units) n/a = irrigation application rate (it/yr)
1 .OO = total supplyklemand ratb (no units: Jul = maximum irrigation demand month Jan = minimum irrigation demand monlh
4.82 = maximum RW supply used (mgd) 0.00 = maximum other supply used (mgd)
4.30 = maximum reservoir inflow used (mgd)
5.30 = maximum reservoir outllow used (mgd)
1,644 = maximum reservoir working storage used (a&)
5,400 = annual total demand (ac-fvyt)
Monthly Supply I Demand
1 .ow n 900 -. IODemandI i
Jan Feb Mar apr May Jm Jul Aup SeP Oca Nav Dec
Month
I
I
i
i i I I
I
I
I
i i I
I i I
I
i
Monthly Reservoir I Unused RW Supply
Jan Feb Mar Apr May Jun Jul Aug Sep ocl Nav Ce
Month
F:\Prq~U\P~e11.20~CACarlSbad Ph II.M)l\ReseIvcihRevMoSOS . ZA-Phase ii
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 28: With No Seasonal Storage
SUPPLY: RWe8.00 mgd; Other=2.12 rngd QEMAND: Phase II 8 5,400 ac-ftlyr
TORAGE: 0 ac-fi existing seasonal storage, 0 ac-fl required seasonal storage
Evapo- Seasonal
transpir., Precip., Variation
Month in in Ratio
0.11
0.16' Jan n/a ?a Feb n/a n/a
Mar n/a nla 0.37
da nla 0.82
May .da nla 1.37 Apr
JUn nla n/a 1.83
Jul nla nla 2.1 0
Aug n/a n/a 1.76
Nov da n/a 0.42
D&?C nla nla 0.46
TOTAL da nla 12.00
sep nla nla 1.51
oct nla nla 1.09
_____ __-_----I
,,
Project Other Total RW Other Total Reser. Reser. Unused Demand, Demand, Demand, Supply, Supply, Supply, Flow, Storage, RW Supp. aC-ftc ac-ft ac-ft ac-ft' ac-ft' ac-ft ac-ft' ac-ftP e-fi
I 49 0 49 49 0 49 0 0 699
73 0 73 73 0 73 0 0 674'
168 0 168 168 0 168 0 0 579
370 0 370 370 0 370 0 0 377 r
61 5 0 615 615 0 615 0 0 132
824 0 824 747 77 824 (0) (0) 0
945 0 945 747 198 945 (0) (0) 0
791 0 791 747 44 791 0 (0) 0
678 0 678 678 0 678 0 (0) 69
490 0 490 490 0 490 0 0 257 las 0 188 1 88 0 1 88 0 0 559
209 0 209 209 0 209 0 0 538
5,400 0 5,400 5,081 319 5,400 (0) 3,865
----I------------------ -------- -I___ __-___________ ____
- INPUT
nla = effeaivehotal precipitation ratio (no units] nla = imgation efficiency (no units) a) b) c) 5.400 = annual project irrigation deMnd (ac-fVyr) . . 8.00 = maximum recycled water supply available (mgd:
200 = maximum other water supply available (mgd: d)
e) f] . 0.00 = maximum reservoir inflow'allowed (mgd] 0.00 = maximum reservoir outflow allowed (mgd] 0 = maximum reservoir working storage available (ac-ft]
Monthly Supply I Demand I
t- +- I E- -
1 I Jan Feb Mar Apr May Jun Jul Aug Sop Oct Nov Dec
Month I
OUTPUT
2.10 = peak month factor (no units) Ma = irrigation application rate (Wyr)
5,400 = annual total demand (ac-Wyr)
1 .OO = total supply/demand ratio (no units;
Jul = maximum irrigation demand month Jan = minimum irrigation demand month
2.1 2 = maximum other supply used (mgd]
0.00 = maximum reservoir inllow used (mgd] 0.00 = maximurn reservoir outflow used (qd]
1)
2)
3)
4)
5)
6) 7) 8.00 = maximum RW supply used (mgd)
8)
9)
10)
11) 0 = maximum reservoir working storage used (ac-11)
II Monthly Reservoir I Unused RW Supply
1 1.' 800
Jan Feb Mar Apr May Jun Jul AUQ Sep On Nov Dec
Month
F:\Prqeccs\PoweH.ZOAarlsbad Ph 11.001WeservciARevMoSOS - 29-Phase II
Other Total
Month in in Ratio ac-ft ac-ft ac-tt ac-tt' ac-ft ac-tt
Jan n/a nla 0.1 1 49 0 0 1 24
0 1 49
0 168
0 370
Feb n/a n/a 0.16 73 0
Mar n/a n/a 0.37 168 0
n/a n/a 1.37 615 0 61 5 0 61 5 Apr
Jun n/a n/a 1 .83 824 0 747 62 809 May
Jul da nla 2.1 0 94s 0 747 62 809.
Aug n/a nla 1.76 791 0 791 747 44 791
Nov n/a n/a 0.42 188 0 188 188 0 1 88
Dec n/a nla 0.46 209 0 209 209 0 209
TOTAL n/a nla 12.00 5,400 0 168 5.400
Evapo- Seasonal Project Other Total RW
transpir., precip., Variation Demand, Demand, Demand, Supply, Supply, Supply,
n/a n/a 0.82 370 0 370 370
SeP n/a n/a 1.51 678 0 678 678 0 678
Oct n/a nla 1.09 490 .o 490 490 0 490
- INPUT
Rescr. Reser. Unused
Flow, Storage, RW Supp.
ac-tt ' ac-tt* ac-tt
76 76 623
76 151 598
0 151 579
0 151 377
0 151 132
(15) 136 0
(1 36) (0) 0
.O 0 0
0 0 69
0 0 257
0 0 559
538 0 0
(0) 3,734
----
n/a E effeclivefiotal precipitation ratio (no units) n/a I irrigation efficiency (no units) 5.400 = annual project irrigation demand (ac-fUyr)
a) b) c) d)
e)
1)
8.00 E maximum recycled water supply available (wd:
2.00 = maximum other water supply available (mgd:
8.00 = maximum reservoir inflow allowed (mpd)
8.00 E maximum reservoir outflow allowed (mgd) 9) 151 = maximum reservoir working storage available (ac-ft)
Monthly Supply f Demand
1 .OOO
900 n
Jan Feb Mar Apr May Jun Jul Aug Sep On Nov Dec I i Month
OUTPUT
2.10 = peak month factor (no units)
5.400 = annual total demand (ac-wr)
1 .OO = total supply/demand ratio (no units:
. Jul = maximum irrigation demand month Jan = minimum imgalion demand month
8.00 = maximum RW swply used (mgd)
0.66 = maximum olher supply used (rngd) 0.81 = maximum reservoir inflow used (mgd) 1.46 = maximum reservoir outflow used (mgd)
151 = maximum reservoir wolking storage used (ac-11)
Ma = irrigation application rate (fvyr)
Monthly Reservoir f Unused RW Supply
700 , I
JZn Feb Mar Apr May Jun Jul Aug Sep On Nw Dec
Month i 1
F:\Projece\PowelI,20ACarlsbad Ph 11.001\ReseNoinRevMoSD~ .ZC-Phase II
Evapo- Seasonal Project Other Total
transpir., Precip., Variation Demand. Demand, Demand,
Month in in Ratio amE ac-tt ac-n
Jan n/a da a1 1 88 0 88
Feb n/a da 0.1 6 133 0 133
Mar nla n/a 0.37 304 0 304
nla nfa 0.82 672 0 672
by n/a nfa 1.37 1.116 0 1,116 Apr
Jun n/a n/a 1 33 1,496 0 1,496
Jul da n/a 2.1 0 1,716 0 1,716
AUQ n/a n/a 1.76 1,436 0 1,436
SeP n/a n/a 1.51 1,230 0 1,230
oct n/a n/a 1.09 889 0 889
Nov n/a nfa 0.42 341 0 341 n/a nla 0.46 379 0 379
._---.----------I - Dec
TOTAL n/a nla 12.00 9,800 0 9,800
INPUT
Other Total Reser. Reser. Unused RW
Supply, Supply, Supply, Flow, Storage, RW supp., ac-n ac-fl’ ac-ttg ac-fi ac-no ac-n
817 0 81 7 729 1,642 1.051
817 0 817 6&l 2.326 1,OSl
817 0 817 51 2 2.838 1,051
81 7 0 817 145 2.983 1,051
(299) 2,683 1.051 817 0 817
817 0 81 7 (679) 2,004 1,051
81 7 0 817 (899) 1,105 1,051
81 7 0 817 (61 9) 486 1,051
81 7 0 817 (41 4) 73 1,051
817 0 817 (73) 0 1,051
81 7 0 81 7 476 476 1,051
817 0 817 438 91 4 1,051 ---------------~---.-----------_---_I-__--------________I___
9,800 0 9,800 0 12,613
nla = effectivehotal precipitation ratio (no units) nla e irrigation eniciency (no units)
9.800 = annual project imgation demand (ac-Wyr) 20.00 = maximum recyded water supply available (mgd: 0.00 = maximum other water supply available (rngd:
12.00 = maximum reservoir inflow,allowed (mgd) 12.00 z maximum reservoir oulllow allowed (mgd)
a) b) c) d) e)
f)
g) 3,000 maximum reservoir working storage available (ac-it)
3’-
Monthly Supply / Demand
-__--------_----__-_---- ------n -I
Jan Feb Mar Apr May Jun JUl hg Sep On Nov Dec
Month !
OUTPUT -
2.1 0 = peak mqnth factor (no units) Wa = irrigation application rate (tvyr) 9.800 = annual total demand (ac-Wyr) 1 .OO = total supply/demand ratio (no units: .
Jul = maximum irrigation demand month Jan = minimum irrigation demand month
8.74 = maximurn RW supply used (mgd) 0.00 = maximum other supply used (mgd)
7.80 = maximum reservoir inflow used (mgd) 9.63 = maximum resewoir outflow used (mgd)
2.983 = maximum reservoir working storage used (ac-11)
Jan Feb Mar Apr May Jun Jul Aug Sep Nov Dec
Month
F:\Prolens\Powell.ZO~M)at(sbad Ph 11.001\ReservoIfiRevMSDS ~ JA-Ultimale 5131x10
Analysis of Monthly Supply/Demand/Storage Requirements
Vlonth
Jan
Feb
Mar
May
Jun
Jul
Aug
Sep oct
Nov
Dec
TOTAL
Apr
__--.
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 38: With No Seasonal Storage
SUPPLY: RW=18.37 mgd: Otherd mgd
qEMAND: Ultimate 0 9,800 ac-wr
‘ORAGE: 0 ac-fi existing seasonal storage, 0 ac-tt required seasonal storage I
Evapo- Seasona
transpir., Precip., Variation
in in Ratio
n/a n/a 0.1 1
n/a n/a 0.16
n/a n/a 0.37
n/a n/a 0.82
n/a 1.37 n/a n/a n/a 1.83
nla nla 2.1 0
n/a nla 1.76 n/a n/a 1.51
n/a n/a 1.09 n/a n/a 0.42
n/a n/a 0.46
Ida n/a 12.00
-----------I-
RW Other Total
Supply, Supply, Supply, ac-ft * ac-tt ac-fl
88 0 88
133 0 133
304 0 304
672 0 672
1,116 0 1.116
1,496 0 1,496
1,716 0 1,716
1,436 0 1,436
1,230 0 1,230
341 0 341
379 0 379
9,800 0 9.soO
889 0 889 ,
--------_--------_A
Project Other Total
Demand, Demand, Demand,
ac-fl ac-fl ac-fl
88 0 88
a 133 0 133
304 0 304
672 0 672
1.116 0 1,116
1,496 0 1,496
1,716 0 1,716
1,436 0 1,436
1,230 0 1,230
889 0 889
341 0 34 1
379 0 379
9,800 0 9.800 .
.--_-__-_----------l_____l_______l
Reser. Reser. Unused
Flow, Storage, RW Supp..
ac-ft’ ac-ft ac-ft
0 0 1,780
0 0 1,735
0 0 1,563
0 0 1,196
0 0 752
0 0 372
0 0 152
0 0 432
0 0 638
0 0 979
0 0 1,527
0 0 1,489
0 12,613
-------- I
INPUT
-i I o Demand W,
n/a = effediveAota1 precipitation ratio (no units) n/a = irrigation eliiciency (no units) a) b) C) 9,800 = annual project irrigation demand (ac-Wyr) d) 20.00 E maximum recycled water supply available (mgd:
e) I\ 0.m = maximum reservoir inllom allowed (mgdl 0.00 = maximum other water supply available (mgd:
0.6 maximum reservoir outflow atlowed (&hl
0 t maximum resevoir working storage available (ac-11)
,200
.m
800
4w
200
0
Jan Feb Mar Apr MY Jun Jul Aug Sp On Nov Dec
Month
2.10 = peak month factor (no units) n/a = irrigation application ratr (ttlyr) 9.800 = annual total demand (ac-tuyr) 1.00 = total supply/demand ratio (no units:
Jul z maximum irrigation demand month
Jan = minimum irrigation demand month
18.37 = maximum RW supply used (mgd) 0.00 = maximum other supply used (mgd)
0.00 = maximum reservoir inflow used (mgd)
0.00 = maximum reservoir outflow used (mgd)
0 = maximum reservoir working storage used lac*)
I1 Monthly Reservoir I Unused RW Supply
i I *’ 2.m
I Jan Feb Mar Apr May Jun Jul Aug Sep Oa Nov Dec
Month
F:\Prqec~\Powell.20ACarlsbad Ph It Wl\ReservoihRevMSCS. 38-lJllmele 5/31/00
Analysis of Monthly Supply/Demand/Storage Requirements
Month
Jan
Feb
Mar
Apr
May
Jw,
Jul
AUQ
SeP
OCt
Nov
DeC _---I.
'TOTAL
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 3C: With Mahr Reservoir Seasonal Storage
SUPPLY: RW=16.76 mgd; Other=O mgd
TEMAND: Ultimate 43 9,800 ac-Wyr b FORAGE: 0 ac-ft existing seasonal storage, 151 ac-ft required seasonal storage
Evapo- Seasonal
transpir., Precip., Variation
in in Ratio
rda nla 0.1 1
da nla 0.1 6
rda nla 0.37
nla n/a 0.82
nla n/a 1.37
n/a n/a 1 .83
n/a n/a 2.1 0
n/a nla 1.76
n/a n/a 1.51
n/a n/a 1.09
n/a n/a 0.42
n/a n/a 0.46
n/a n/a 12.00
___-__-___--__-- ------
- INPUT
Project Other Total
Demand, Demand, Demand,
ac-tt ac-tt ac-tt
88
133
304
672
1,116
1,496
1,716
1,436
1,230
889
341
379
0
0
0
0
0
0
0
0
0
0
0
0
88
133
304
672
1,116
1,496
1,716
1,436
1,230
889
341
379
9,800 0 9,800
RW Other Total
Supply, Supply, Supply, ac-tt ac-tt ac-n
164 0 164
208 0 208
304 0 304
672 0 672
1,116 0 1,116
1,496 0 1,496
1,565 0 1,565
1,436 0 1,436
1,230 0' 1,230
889 0 889
I 341 0 341
379 0 379
~ 9,800 0 9.800
p------------------
a) b) c) d) e) 0.00 = maximum other water supply available (mgd:
1) 3.00 E maximum reservoir inflow allowed (mgd) 3.00 = maximum reservoir outflow allowed (rngd; 9) 151 = marimurn reservoir working storage available (ac-rt)
n/a = eflectivehotal precipitation ratio (no units)
n/a E irrigation efliciency (no units)
9,800 = annual project irrigation demand (ac-Wyr]
20.00 = maximum recycled water supply available (mgd:
I Monthly Supply I Demand
2.000
1.800 1 DDsmand 7 -i
,400
200
.wo
800
600
400
200
0
Jan Feb Mar Apr May Jun Jul AUQ Sep (kc Now Dec I Month I
OUTPUT
ReSer. Reser. Unused
Flow, Storage, RW Supp.
ac-tt ' ac-n W-ft
76 76 1,704
76 151 1,659
0 151 1,563
0 151 ' 1,196
0 151 752
0 151 372
. (151). 0 303
0 0 432
0 0 638
0 0 ' 979
0 0 1,527
1,489 0 0
0 12.613
---. -----
2.10 = peak month factor (no units) n/a = irrigation application rale (W)
9.800 = annual total demand (ac-ftlyr)
1 .00 = total suppIy/demand ratio (no units; Jul = maximum irrigation demand month Jan = minimum irrigation demand month
16.76 = maximum RW supply used (mgd) 0.00 = mimum other supply used (mgd)
0.81 = maximum reservoir inflow used (mgd) 1.61 = maximum reservoir outflow used (mgd) 151 = maximum reservoir working storage used (ac-ft)
..
I Monthly Reservoir I Unused RW Supply
1.800 7 t1
F:\Prqeccs\Powell.2OM)arlsbad Ph 11.001\ReservcihRevMoSDS. 3GUlimale
Appendix C
EMERGENCY STORAGE MODEL RUNS
,
CGVL ENGINEERS IN .4SSOClATlON WITH JOHN POWELL & ASSOCIATES c- 1
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: CMWD Recycled Water System Expansion SCENARIO 2D: With Mahr Reservoir Seasonal and Emergency Storage SUPPLY: RW=8.00 mgd with loss of 149 ac-ft in February; Olhek0.66 mgd
'IEMAND: Current 0 5,400 ac-ftlyr
TORAGE: 0 ac-ft existing Seasonal Storage, 151 ac-ft required seasonal storage
Evapo- Seasonal
transpir., Precip., Variation
Month in in Ratio
Jan da n/a 0.1 1
Feb da nla 0.1 6
Apr
Jul nla da 2.1 0
Mar n/a da 0.37 n/a n/a 0.82
May n/a nla 1.37
Jun nla n/a 1.83
Aug nla n/a 1.76
SeP n/a n/a 1.51
Nov n/a nla 0.42
oct n/a nla 1.09
Dec n/a nla 0.46
TOTAL nla n/a 12.00
.-___-__. _l___---_-l------------I
Project Other Total
Demand, Demand, Demand,
ac-ne ac-tt ac-ft
49 0 49
73 0 73
168 0 168
370 0 370
61 5 0 615
824 0 824
94s 0 945
791 0 791
678 0 678
490 0 490
188 0 188
209 0 209
5,400 0 5,400
--------------- --_---________-
- INPUT
n/a = effectivehotal precipitation ratio (no units) n/a = irrigation efficiency (no units) a) b) c) 5.400 = annual project irrigation demand (ac-Wyr) ' 8.00 = maximum recycled water supply available (mgd:
2.00 = maximum other water supply available (mgd: d)
8.00 = maximum reservoir inflow allowed (mgd) e)
8.00 = maximum reservoir outflow allowed (mgd) f)
151 = maximum reservoir working storage available (ac-It)
RW Other Total
SUPPlY, supply, Supply, ac-tt ac-ft ac-ft
124 0 124
0 0 0
317 0 31 7
370 0 370
61 5 0 615
747 62 809
747 62 809
747 44 791
678 0 678
490 0 490
188 0 188
209 0 209
5,232 168 5,400
I-------------
Monthly Supply I Demand
n i 1 .wo
I, 900 I 0 Demand
Reser. Reoer. Unused
Flow, Storage, RW Supp.,
ac-ft ' ac-ftQ sc-tt
76 76 623
(73) 2 747
1 49 151 430
0 151 377 '
0 151 132
(1 5) 136 0
(136) (0) 0
0
(O) 69
0
0 (0)
0 0 257
0 0 559
0 0 538
0 3.733
--II- I
Jan Feb Mar Apt May Jun Jul Aug Sep Oct Nm DQc
Month
OUTPUT
2.10 =peak mnth factor (no units) Wa = irrigation application rate ((Vyr)
5.400 = annual total demand (ac-Wyr) 1 .OO = total supply/demand ratio (no units;
Jul = maximum irrigation demand month
Jan = minimum irrigation demand month
8.00 =maximum RW supply used (mgd)
0.66 = maximum other supply used (mgd)
1.60 = maximum reservoir intlow used (rngd)
1.46 = maximum reservoir outflow used (mgd)
151 = maximum reservoir working storage used (ac-R)
'
Jan Feb Mar npr May Jun Jul Aug Sep On Nm Dec
Month
F:\Prqecls\Powell.207Carlsbad Ph 11.001WeservCirWevMSDS. 20-FebEmerg
Evapo- Seasonal
transpir., Precip., Variation
Month in in Ratio
Jan nla n/a 0.1 1
Feb n/a n/a 0.16
Mar nla n/a 0.37
May nla n/a 1.37
Apr
Jun nla nla 1.83
Jul da da 2.1 0
Aug n/a nla 1.76
SeP nla n/a 1.51
oct n/a n/a 1.09
Nov nla n/a 0.42
Dt?C nla nla 0.46
TOTAL nla n/a 12.00
nla n/a 0.82
_____. _I_F__-___---- ---I-------
- INPUT
Project Other Total RW Other Total Reser. Reser. Unused
Demand, Demand, Demand, Supply, Supply, Supply, Flow, Storage, RW supp., ac-ft' ac-ft ac-ft ac-no ac-tt ac-ft ac-tt' ac-ftQ ac-ft
49 0 49 124 0 124 76 76 623
a 73 0 73 149 0 149 76 151 598
168 0 1 68 17 0 17 (151) 0 730
615 0 615 615 0 615 0 151 132
824 0 824 747 62 809 (15) 1 36 0 945 0 945 747 62 809 (136) (0) 0
791 0 791 747 44 791 0 (0) 0
678 0 678 678 0 678 0 (0) 69
490 0 490 490 0 490 0 01 257 188 0 188 188 0 188 0 0 559
209 0 209 209 0 209 0 0 538
5,400 0 5.400 5,232 168 5,400 (0) 3,734
370 0 370 521 0 521 151 151 226
--------------------____I_______________-----------------_-_-__ ___ -
a)
b) c) d) e) f)
n/a = eflectiveAotal precipitation ratio (no units) n/a I irrigation eniciency (no units)
5,400 = annual project irrigation demand (ac-tVyr;
8.00 = maximum recycled water suppv available (mgd: 2.00 = maximum other water supply available (mgd:
8.00 = maximum reservoir inflow allowed (mgd) 8.00 = maximum reservoir outflow allowed (mgd) a) 151 = maximum reservoir working storage available (ac-It)
OUTPUT
2.10 = peak month factor (no units) n/a = irrigation application rate (ft/yr)
5,400 = annual total demand (ac-WyrJ 1.00 = total supplyldemand ratio (no units:
Jul = maximum irrigation demand month Jan = minimum irrigation demand month
8.00 = maximum RW supply used (mgd) 0.66 = maximum other supply used (mgd) 1.61 = maximum reservoir inllow used {mgd) 1.61 = maximum reservoir outflow used (mgd) 151 = maximum reservoir working storage used (ac-ft) .
I I I I
Monthly Supply I Demand Monthly Reservoir I Unused RW Supply I
1
- 'X -
e
a d E a - 0 >
.m
900
800
700
600
500
400
300
200
100
D
Jan Feb Mar Apt May Jun Jul hQ SeP On Nov Dec
Month
500
400
200
loo
0
Jan Fet Mar Apr May Jun Jul Aug Sep On Nov Dec
Month
F:\ProjecU\Powell.Z07ar$bad Ph 11.00IWerewoifiRevMoSDS ~ ZD-MarEmerg
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 2D: With Mahr Reservoir Seasonal and Emergency Storage
SUPPLY: RW=8.00 mgd with loss of 131 ac-ft in April; Olher=0.66 mgd
TEMAND: Current 0 5,400 ac-fUyr
fORAGE: 0 ac-ft existing seasonal storage, 151 ac-ft required seasonal storage
Evapo- Seasonal
transpir., Precip., Varjation
in in Ratio Month
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
-P
Oct Nov
Dec
TOTAL
--I-
Project Other Total
Demand, Demand, Demand,
ac-ftC ac-it ac-ft Supply, SuPPlY, Supply, ac-fta ac-it‘ ac-it
124 0 124
149 0 149
168 0 168
239 0 239
747 0 747
747 62 809
747 62 809
747 44 791
678 0 678
490 0 490
1 88 0 188
209 0 209
5,232 168 5,400
.-------------------____II
Flow, Storage, RW Supp.
ac-ft ’ ac-ft ac-R
76 76 623
76 151 s98
0 151 579
(1 31 1 20 508
1 32 151 0
(1 5) 136 0
(1 36) (0) 0
0 (0) 0
0 (0) 69
0 0 257
0 0 559
0 0 538
0 3.733
--------__-----_~
- INPUT
~ da n/a 0.1 1
da n/a 0.16
rda n/a 0.37
n/a n/a 0.82 n/a n/a 1.37
n/a n/a 1 .83
nla nla 2.1 0
n/a n/a 1.76
n/a da 1.51
n/a nla 1.09 n/a da 0.42 n/a n/a 0.46
n/a da 12.00
n/a I effectiveftotal precipitation ratio (no units) nla = irrigation efficiency (no units) 5,400 = annual project irrigation demand (ac-Wyr) 8.00 E maximum recycled water supply available (mgd: 2.00 = maximum other water supply available (mgd; 8.00, I maximum reservoir inflow allowed (mgd)
8.00 = maximum reservoir outflow allowed (mgd]
151 = maximum reservoir working storage available (ac-R)
49 0 49
73 0 73
168 0 168
370 0 370
615 0 61 5
945 0 945
791 0 791
678 0 678
490 0 490
1 88 0 188
209 0 209
5,400 0 5,400
824 0 824
1___-___1_-_1----------------1--_-----_____I__________
Monthly Supply / Demand
n i 900
Jan Feb Mar Apr May Jun Jul Aug Sep Oa NW De:
Month i
Other Total I Reser. Reser. Unused RW
OUTPUT
2.10 = peak month factor (no unlts) n/a = irrigation application rate (ft/yr) 5,400 = annual total demand (ac-Wyr]
1 .OO = total supplyidemand ratio (no units; Jul .= maximum irrigation demand month Jan = minimum irrigation demand month
8.00 = maximum RW supply used (mgd)
0.66 = maximum other supply used (mgd)
1.41 = maximum reservoir inflow used (mgd) 1.46 = maximum reservoir outflow used (mgd)
151 = maximum reservoir working storage used (ai-ft)
Monthly Reservoir I Unused RW Supply i
I I I
i Jan Feb Mar Apr May Jun Jul AuQ Sep On NO^ Dec i Month I
b I
)tes:
EXHIBIT C Method of Calculating Recycled Water Rate
FY 2002103 Allocated to h4RF Tertiary Facilities Budget Percent Amount (1)
MRF Plant Costs
Labor s 210,000 * 25.0% $ 52,500
Materials 740,000 9.6% 71,040
Power 225,000 25.0% 56,250 Other operating costs 43,000 50.0% 21,500
Mahr Reservoir 17,000 100.0% 17,000
Capital Recovery 1 10,926 Overhead - Wastewater Department s 445,000 9.0% 40,050
Overhead - District Wide 3,658,000 1.9% 69,502 Total Annual Costs to Recover 498.138 Quarterly Payments -? 4
Total Quarterly Payment due to VALLECITOS - Lift Station No. 1 60,000 100.0% 60,000
,
Post-mansion Annual Cost (1) Anticipated Allocated to MRF Tertiary Original or
Actual Costs Annual Costs Percent Amount
Post-Expansion Facilities
MRF Plant costs (2) Labor
Materials
Power
Other operating costs
Lift Station No. 1
Mahr ’Reservoir
Overhead - Wastewater Department
Overhead -District Wide
Capital Recovery (3) Existing filtration plant
Existing disinfection facility
Existing effluent pumping station
Existing microscreen
Existing Mahr Reservoir (4)
Expansion design costs
Expansion of filtration plant
Expansion of disinfection facility Total Annual Costs to Recover
t
.
$ 613,821
158,041
155,602
2 1 9,84 1
125,000
204,923
977,000
336,000
$ 329,000
237,000
539,000
90,000
126,000
15,000
500,85 1
4,117,111
53,516
13,779
13,566
19,167
6,975
17,866
85,179
29,294
25.0?’0
9.6%
25.0%
50.0%
100.0%
100.0%
9.0%
.1.9%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
S 82,250
22,752
134,750
45,000
126,000
15,000
45,077
78,225
53,516
13,779
13,566
19,167
10,898
17,866
85,179
29,294
792.319 12 Number of months per year -
w Total Monthly Payment due to VALLECITOS
Annual costs shall be set each year based on budgeted amounts and retrospectively adjusted to audited amounts after year-end described
in Section 13 of the agreement. MW Plant Cos& - Operating costs for labor, materials, power, “other operating costs”, Lift Station No. 1, Mahr Reservoir and overhead
will be reviewed at year-end and adjusted to reflect actual costs. For Capital Recovery the costs will be specifically identified as to
primary, secondary, and tertiary treatment. (i.e., 0% will be allocated to MRF Tertiary for costs specifically identified to primary and
secondary treatment while 100% of tertiary treatment costs will be allocated to MRF Tertiary. “Other operating costsy’ include
miscellaneous items such as telemetry, telephone lines, minor repairs, etc.
Vallecitosa actual costs of expansion design; filtration plant and disinfection facilities shall be used, when calculating capital recovery.
Val]ecitos’ cost of subsequent replacement of MRF tertiary facilities will replace original costs used for calculating capital recovery.
Existing facilities no longer needed for tertiary processes will be eliminated from the capital recovery calculation. Capital recovery shall
be calculated based on an engineering economic formula using a uniform series capital recovery factor with a compound interest of six (6)
percent, and a twenty-year life. Mahr Reservoir value is based upon the existing inletloutlet piping through the reservoir, leakage recovery piping, and fencing, access road
and overflow facilities only. The existing dam drainage pump back system and inletloutlet facilities will be replaced with new facilities
identified in Exhibit ‘23’’.
’