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TITLE: APPROVE AGREEMENT WITH - VALLECITOS WATER DISTRICT FOR SALE OF
RECYCLED WATER AND USE OF MAHR RESERVOIR
PROJECT NO. 3675-3 CITY MGR. a
RECOMMENDED ACTION:
Adopt Resolution No. 1188
of Recycled Water and Use of Mahr Reservoir, Project No. 3675-3.
to approve Agreement with Vallecitos Water District for Sale
ITEM EX P LAN AT10 N :
On June 13, 1991, the Carlsbad Municipal Water District (CMWD) entered into an agreement with
Vallecitos Water District (VWD) to purchase 2.0 million gallons per day (mgd) of recycled water
from the Meadowlark Reclamation Facility (MRF). The MRF is located near the intersection of
Rancho Santa Fe Road and Melrose Drive. The existing agreement is a "take or pay'' agreement in which CMWD must pay for 2 mgd whether CMWD uses the recycled water or not. The recycled
water from the MRF is the major supply to CMWD's existing Encina Basin Water Reclamation
Program referred to as the Phase I project. This 1991 agreement is for a term of 20 years, which
will terminate in June 201 1.
CMWD has now initiated the final design and construction of its Encina Basin Water Reclamation
Program, Phase II Project (Phase 11). An integral part of the Phase II project includes obtaining an
additional 1.0 mgd of recycled water from the MRF, and incorporating an earthen dam reservoir,
referred to as Mahr Reservoir, into CMWD's recycled water distribution system. Both the MRF and Mahr Reservoir are owned and operated by VWD.
To supply the additional 1.0 mgd of recycled water from MRF, VWD's Board approved an
expansion of the MRF from a capacity of 2.0 mgd to 5.0 mgd using its own funding. The VWD
Board's decision to expand to 5.0 mgd is based on constructing the maximum size wastewater
treatment facility at the MRF site. This action reduced CMWD's Phase II construction cost by
$5 million because VWD is performing the MRF expansion work at its cost. VWD is planning to
complete the MRF expansion in 2005, at which time VWD proposes to sell CMWD 3.0 mgd of the recycled water supply, and utilize the remaining 2.0 mgd in its service area or to sell to another
party-
A new agreement has been prepared between CMWD and VWD to purchase the additional 1 mgd
of recycled water from the MRF. The supply (meaning: the amount of recycled water CMWD
purchases from VWD) would increase from the current 2.0 mgd up to 3.0 mgd until termination of
the agreement in 2025. The new agreement also allows CMWD to use Mahr Reservoir, which has
a storage capacity of 54 million gallons. This storage is sufficient to supply another 1 mgd during
the summer months to meet the project's projected recycled water demands. The proposed
agreement is for a period of twenty-two (22) years and contains the following primary conditions.
Meadowlark Reclamation Facility
1. CMWD will continue to purchase 2.0 mgd (2,240 acre-foot per year) from MRF at the current rate of $361 per acre-foot (AF) through fiscal year 2003/2004.
2. Starting in fiscal year 2004/2005, the cost of the recycled water will be based on actual
expenses to operate and maintain the tertiary facilities at the MRF plus the capital recovery cost of those facilities. The total cost is presently estimated at $498,138 per year,
or $222/A F.
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Page 2 of Agenda Bill No. 553
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Upon completion of the MRF expansion and delivery of 3.0 mgd, CMWD will purchase a
minimum of 2.0 mgd during the months of December through March and a minimum of
3.0 mgd for the remaining months of the year. The purpose of varying the supply
throughout the year is to have the supply more closely match the demand for water, which is generally less in the winter months.
A meter will be paid for and installed by CMWD to monitor flows delivered to CMWD.
In the event VWD generates more flow at MRF than can be utilized by either CMWD or
VWD, then CMWD shall be responsible for disposal of any excess recycled water through
its transmission main system and, if necessary, eventual disposal to the flow equalization
tanks being constructed by the Encina Wastewater Authority (EWA). Since CMWD does
not own the flow equalization tanks, this condition has a stipulation that EWA can refuse this excess water, which may occur when EWA needs to use the flow equalization tanks
for emergency storage or when maintenance and repairs are being performed on the
tanks. In the event EWA cannot receive the recycled water at the flow equalization tanks,
then the recycled water will be placed in the outfall sewer pipeline.
The water quality requirements of the recycled water treated at MRF and delivered to
CMWD shall always meet or exceed the requirements for use in non-restricted recreational
impoundments (i.e., suitable for body contact) in compliance with criteria in Title 22
California Code of Regulations.
Water pressure from MRF shall be adequate to fill Mahr Reservoir. Mahr Reservoir is at an
ideal elevation because it matches CMWD's pressure zone for the area, which has a
550-foot hydraulic grade line elevation.
The cost of the water will vary depending upon the annual cost to produce tertiary treated
water, and whether the treated water is purchased prior to the expansion (pre-expansion) of the MRF or after the expansion (post-expansion). The annual cost is based on VWD's
budgeted annual figures at the beginning of each fiscal year and then adjusted to actual
cost through retrospective adjustments after the conclusion of each fiscal year. The annual cost includes operational, overhead, and capital recovery costs for the MRF tertiary facilities, Mahr Reservoir, and Lift Station No. 1. Lift Station No. 1 is used by VWD to divert
wastewater to the MRF from their interceptor sewer proceeding to the Encina Water
Pollution Control Facility because VW D cannot always supply the treated recycled water
demand only from the MRF service area.
Capital recovery costs only apply to tertiary facilities that are funded and constructed by
VWD. The life of these facilities is listed at 20 years. The annual capital recovery cost is
calculated assuming a 6% discount factor. The purpose of capital recovery is to enable
VWD to replace equipment, structures, and electrical components as needed during the
life of the agreement.
The maximum cost for recycled water in any fiscal year shall not exceed 75 percent of CMWD's wholesale potable water cost from the San Diego County Water Authority.
CMWD must purchase the minimum quantities of recycled water stated in the agreement
or it will be in breach of the agreement. VWD can terminate the agreement after 60 days written notice if CMWD fails to pay for the recycled water, fails to accept the recycled water
as produced, fails to maintain facilities, or other substantial failure. CMWD may terminate
the agreement if VWD refuses to supply the treated water to CMWD for any reason.
Both parties have 60 days to correct or reconcile any problem before the agreement is terminated.
Page 3 of Agenda Bill No. 553
Mahr Reservoir
1. CMWD shall be permitted to make improvements to Mahr Reservoir, and shall pay for the
improvements at a current estimated cost of $2 million dollars. Following is a list of the
improvements:
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Removal of debris and fine grading of the interior area of Mahr Reservoir.
Installation of an aeration system, disinfection system, and chemical treatment.
Reconfiguring and constructing a new inlet/outlet structure and piping.
Installing a floating cover and liner.
2. CMWD is entitled to use 32 MG of the storage volume in Mahr Reservoir. The remaining
balance of 22 MG is allocated to VWD. In addition, CMWD loses its capacity of 32 MG if
CMWD fails to purchase the minimum quantities of recycled water in accordance with this
agreement, and if this occurs, VWD is not responsible for repaying to CMWD the cost of
any improvements noted under item 1.
3. VWD shall operate and maintain Mahr Reservoir in accordance with an operations and
maintenance manual prepared by CMW D.
After carefully reviewing the risks and benefits to CMWD in the proposed agreement with VWD,
staff recommends that the Board approve the agreement. The agreement will begin
upon execution by the City Council. Therefore, the existing agreement shall be rescinded by the
Board on the same date.
ENVIRONMENTAL REVIEW:
The improvements to Mahr Reservoir are contained in the project description for Phase II.
A Mitigated Negative Declaration was prepared for the Phase II project. This was approved by the
City Council on January 25,2000 under Case No. EIA 99-09. The United States Department of the
Interior completed their review of the Phase II project for compliance with the National
Environmental Policy Act (NEPA) and formally approved the NEPA on March 1,2002.
FISCAL IMPACT:
There are two financial impacts resulting from the proposed agreement. The first is the cost of
improvements to Mahr Reservoir described above, which will be funded by CMWD. CMWD will
obtain its funding for improvements to the entire Phase II recycled water system from a $31 million
low-interest loan and a $5 million grant from the State Water Resources Control Board, and an
additional 25 percent project grant from the Federal Bureau of Reclamation. Recycled Water
Funds totaling $2 million have been appropriated for the Mahr Reservoir improvements.
The second impact is the cost of purchasing recycled water from the MRF. CMWD will only pay for
the cost of tertiary treatment and capital recovery cost at MRF, and operation and maintenance
costs at Mahr Reservoir. If VWD uses or sells recycled water to another party, then VWD will
reimburse CMWD its proportionate share of the cost of the improvements to Mahr Reservoir.
The cost share will be a ratio of peak flow rates between the two agencies.
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Page 4 of Agenda Bill No. 553
200312004
200412005
Before MRF is expanded, the capacity at MRF will be 2.0 mgd or 2,240 acre-feet per year (AFY).
The proposed agreement stipulates that the tertiary recycled water rate will be the current rate of
$361/AF for the current fiscal year and payments will be made on a quarterly basis.
For subsequent fiscal years, the cost will be based on VWD's actual costs to operate and maintain
the tertiary treatment system estimated at $387,212 per year plus existing capital recovery costs of
$1 10,926 per year for a total cost of $498,138 per year. Using this cost, CMWD will make quarterly
payments estimated at $1 24,535.
2 mgd 2,240 AFY $808,640 $361 /AF
2 mgd 2,240 AFY $498,138 (a) $222lAF (b)
(Existing Rate)
When VWD completes their expansion of the MRF, the recycled water rate will be based on the
capital recovery costs for tertiary facilities estimated at $243,265 per year, and variable costs
(i.e., labor, materials, and power) estimated at $549,054 per year for a total annual cost estimated
at $792,319. The agreement calls for CMWD to pay VWD in 12 equal payments, which results in a
payment of $66,027 per month. Based on these estimates, the unit cost of recycled water at a
peak demand of 3.0 mgd will be $265lAF.
2005 through
2025
Based on current expenses, recycled water from MRF are estimated to cost as follows:
3 mgd 2,989 AFY $792,319 (a) $265/AF (b)
(a) This value is an estimate of the annual cost in today's dollars.
(b) The actual cost per acre-foot will be based on the actual annual cost divided by the actual
amount of recycled water delivered from VWD. The maximum cost per acre-foot shall not
exceed 75% of CMWD's wholesale imported potable water rate. Currently, CMWD's
wholesale imported water rate is $463lAF. Therefore, the maximum recycled water rate
shall not exceed $347/AF.
The total dollar value commitment, in today's dollars, that CMWD is making by entering into the
proposed agreement with VWD over the life of the agreement is approximately $1 7 million.
EXHIBITS:
1. Location Map.
2. Resolution No. 1188 to approve Agreement with Vallecitos Water District for Sale
of Recycled Water and Use of Mahr Reservoir, Project No. 3675-3.
3. Agreement with Vallecitos Water District.
DEPARTMENT CONTACT: William Plummer, (760) 602-2768, bplum Bci.carlsbad.ca.us
EXHIBIT 1 - LOCATION MAP
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RESOLUTION NO. 1188
A RESOLUTION OF THE BOARD OF DIRECTORS OF
CARLSBAD MUNICIPAL WATER DISTRICT (CMWD)
APPROVING AN AGREEMENT FOR SALE OF RECYCLED
WATER AND USE OF MAHR RESERVOIR WITH VALLECITOS
WATER DISTRICT, PROJECT NO. 3675-2.
WHEREAS, the Encina Basin Water Reclamation Program, Phase II project was
approved for a $31 million low-interest loan and $5 million grant by the State Water Resources
Control Board on January 23, 2002, and a 25 percent project grant from the Bureau of
Reclamation on June 18, 2002; and
WHEREAS, the Phase II project includes the purchase of up to 3.0 million gallons per day
from the Meadowlark Reclamation Facility (MRF) and incorporation of Mahr Reservoir into
CMWD's recycled water distribution system, and both facilities are owned and operated by
Vallecitos Water District; and
WHEREAS, VWD proposes to expand the capacity of MRF from 2.0 mgd to 5.0 mgd; and
WHEREAS, an agreement has been prepared between Vallecitos Water District and
CMWD for the purchase of up to 3.0 mgd of recycled water beginning after the expansion of MRF,
and for CMWD's continuous use of Mahr Reservoir for recycled water storage up to 32 million
gallons; and
WHEREAS, the minimum flow rate to be delivered from MRF to CMWD's water
distribution system will vary during the year from 2.0 mgd during the months of December through
March, and 3.0 mgd during the remaining months of the year for the Phase II project; and
WHEREAS, CMWD's cost for the recycled water will be at the current rate of $361lAF for
'iscal year 200312004, and then change to actual costs for tertiary treatment at MRF of 2.0 mgd
~lus capital recovery costs for fiscal year 200412005, and finally change to actual costs for tertiary
:reatment at MRF for a variable flow rate of 2.0 mgd to 3.0 mgd plus capital recovery cost for the
*emaining years in the 22 year agreement.
NOW, THEREFORE, BE IT RESOLVED by the Board of Directors of Carlsbad Municipal
Nater District (CMWD) of the City of Carlsbad, California, as follows:
1. That the above recitations are true and correct.
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2. That the President of the Board of Directors is authorized to execute the
Agreement for Sale of Recycled Water and Use of Mahr Reservoir between Vallecitos Water
District and CMWD.
3. That the Board rescind the existing agreement between Vallecitos Water District
and Carlsbad Municipal Water District dated June 13, 1991, which will expire in 201 1 for the
purchase of 2.0 mgd, and the rescission shall be effective upon the execution date of the new
proposed agreement by the Board President.
4. That the Board has determined that it is in the best interest of CMWD to anticipate
the recycled water storage capacity needs, and recycled water supply needs, for the Phase II
project, and that the estimated $2 million dollars in improvements to the Mahr Reservoir will serve
the best interests of CMWD, and the recycled water purchasers within CMWD.
PASSED, APPROVED AND ADOPTED at a special meeting of the Carlsbad Municipal
Water District held on the 5th day of AUGUST , 2003 by the following vote, to wit:
AYES: Board Members Lewis, Finnila, Kulchin, Hall, Packard
NOES: None
ATTEST:
(SEAL)
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 from 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.
B. VALLECITOS is currently in the process of evaluating an expansion of the
MRF and the increase in production from 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 Encina Basin Water Reclamation Program, Phase I1 Project (“Phase
July 24,2003 (IO 59AM) G.U)ATA\WP\DOLDOCscdMahrC-5 agr wpd 1
I1 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 of the 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 Improvements. 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, modifjring the
inleuoutlet 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
July 24,2003 (IOS9AM) G\DATA\WPU)(ILDOCs~~~.~~.~d 2
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 Design of Improvements. CARLSBAD shall construct the
Improvements with funding obtained fiom 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
July 24,2003 (IO:59AM) G:U)ATA\WT'DOLDOC\revisedMah&.a!g.w@ 3
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. Ownership. Operation, and Maintenance of Mahr Reservoir Improvements.
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
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 harmful
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 Cauacity 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. Quantities 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 amounts 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 ofthe 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 acre-feet per year.
9. Interruption of Delivery 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, andor 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 (MGL), 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 fiom the MW.
This limitation shall not be applicable ‘to water discharged to the VALLECITOS Failsafe
pipeline.
The Parties hrther 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”) andor the San Diego
County Water Authority (“Water Authority”), the Parties agree that recycled water with TDS
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concentration of no more than 1200 MGL will be an acceptable quality to CARLSBAD
under the terms of this Agreement.
11. Recycled 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 Regulatory Requirements. CARLSBAD agrees to comply
with all applicable recycled water distribution regulations issued and/or 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 CARCSBAD’s jurisdiction shall be in
compliance with CARLSBAD’s discharge order issued by the Regional Board, and that all
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 ($36 1 .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(b), 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 CARLSBAD’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.
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).
MRF Tertiarv Facilities - Filtration, disinfection, and effluent pumping
facilities relating to Tertiary Treatment at the MRF.
July 24,2003 (10.59AM) G\DATA\WPWOLDOC\rcvioedMaM)6 agrwpd 9
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
CARLSBAD.
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. CARLSBAD 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.
July 24,2003 (IO 59AM) G !DATA\WDOLDOfievisedMah% agr wpd 10
15. Right to Sell to OthersAJtilization 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 byVALLECITOS 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 CmSBAD 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 (40%)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.
July 24.2003 (1 059AM) GU)ATA\WPDOLDOC\revisedMahr06.agr.wpd 11
rd
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
1 8. 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. Early Termination. If at any time during the term ofthis 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
July 24,2003 (IO:59AM) G V)ATA\WP\DO~\rrvisedMahr06.sgr.wpd 12
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 hrther
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 of this 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 fbllest extent permitted by law,
to indemnifL 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
July 24,2003 (IO 59Ah4) G U)ATA\WmDOLDOC\rcviredMaM)6 agr wpd 13
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 hllest extent permitted by law, to indemnifjl 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 (IO 59AM) G \DATA\WP\WLDOC\reviredMahr06 agr wpd 14
IN WITNESS WHEREOF, the Parties hereto have caused this Agreement to be
executed and effective as of A1,us-f 20 ,2003.
“VALLECITOS” : “CARLSBAD”:
President President
ATTEST:
General Manager
Date: 8/20 /e)
15 July 24. ?W3 (IO 59AM) G UlATA\WPUlOLDOC\reviredMahr06 ayr.wpd
Carlsbad Municipal Water District
Preliminary Design for the
Encina Basin Phase I1 Recycled Water Distribution System
MAHR RESERVOIR EVALUATION
John Powell 8 Associates, Inc Consulting Civil Engineers
in Association with
LLVL
ENGINEERS
May 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
.. 3-1 .. Facility Sizing Criteria ....................................................................................
Demand Criteria ........................................................ ; ............................... 2-1
System Pipeline Criteria ................................ : ........................................... 2-2 ... ..
Construction Costs ......................................... : ...... : .................................. 2-2
Cost Index and Price Escalation ......... : ..................................................... 2-3
Construction Contingencies ..................................................................... 2-3 ..
Engineering and Administration .............................................................. 2-4
...
Project Cost Data .................................................................. :: ........................ 2-2
...
CHAPTER 3 SUPPLYiDEMANDISTORAGE ANALYSIS ......................... 3-1
Seasonal Storage ............................................................................................ 3-1
Demands ................................................................................................... 3-1
Supplies .................................................. 1 ................................................. 3-2
Emergency Storage ......................................................................................... 3-4
..
Seasonal Balancing .................................................................................. 3-3
..
CHAPTER 4 FACILITY ALTERNATIVES ................................................. 4-1
Possible Facility Improvements ..................................................................... 4-1
Inflow Nutrient Removal ......................................................................... 4-1'
Modified YO Works ................................................................................. 4-2
AeratiodDestratification System ............................................................. 4-5
Outflow Chlorination ............................................................................... 4-8
Outflow Microscreening .......................................................................... 4-9
Reservoir Lining and Covering ................................................................ 4-9
Miscellaneous Site Work ....................................................................... 4-12
Alternative Combinations of Improvements ................................................ 4. 12
CGVL ENGINEERS IN ASSOCL4TION WlTH 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
CHAPTER 6 RECOMMENDATIONS .......................................................... 6-1
Facilities ......................................................................................................... 6.1
Monitoring Program ....................................................................................... 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
Other Seasonal Storage Reservoir Features ...................................... 1-6
CMWD Recycled Water Supply Availability .................................. 3-3
CMWD Peak-Month SupplyDemand Balance ................................ 3-3
Mahr Reservoir I/O Hydraulic Parameters ....................................... 4-5
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
Mahr Reservoir Seasonal Benefits to CMWD .................................. 3-4
Cost Opinion for Mahr Reservoir I/O Works ................................... 4-7
LIST OF FIGURES
Figure 1-3 Mahr Reservoir Features ................................................................... 1-2
Figure 1-2 Mahr Reservoir Volume and Surface Area Curves .......................... 1-3
Figure 2-1 Engineering News Record Construction Cost Index ........................ 2-3
Figure 3-1 CMWD Recycled Water Demand Hydrograph ................................ 3-2
Figure 4-1 Proposed Mahr Reservoir Improvements ......................................... 4-3
. Figure 4-2 Proposed Mahr Reservoir I/O Works ............................................... 4-4
Figure 4-4 Proposed Mahr Reservoir Operations Building Site ........................ 4-8
Figure 4-3 Upper Os0 Reservoir I/O Works ...................................................... 4-6
CGvL ENGINEERS IN ASSOCIAT~ON wm JOHN POWELL & ASSOCIATES 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 ASSOCIAT~ON WITH JOHN POWELL & ASSOCIATES 1-1
a6
Backsround
Dam crest. looking north.
Dam spillway. looking northeast.
Figure 1-1 NIahr Reservoir Features
CG\L ENGINEERS li\l ASSOCIATION WITH JOHX POWELL & ASSOCIATES 1-2
a3
Background
h 5 560
.I
Mahr Resetvoir Volume
I I I -- I I
NlMUMlOPERATlNG ................................................. POOL Q EL. 555 iP..S : .................................... I 1
IIII
11,. ... IIII 530
0 50 100 150 200
Volume, acre-feet
250
600
590
580
570
560
550
540
530
Nlahr Reservoir Surface Area
0.0 2.0 4.0 6.0
Area, acres
8.0 10.0
__
Figure 1-2 Mahr Reservoir Volume and Surface Area Curves
t.
CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES 1-3
Backaround
Mahr Reservoir Operational Issues
Ongoing water quality problems experienced by VWD 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. €hstorically, 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
Irvine 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
Combination of treated wastewater with other water supplies
o Nutrient removal from treated wastewater
LI Use of multiple-port inlevoutlet (YO) works
CGVL ENGINEERS IN ASSOCIATION WITH JOml POWELL & ASSOCIATES 1-4
a9
Background
o Use of an aeratioddestratification system
o Chlorination of reservoir outflow
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
involvement 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 larger than Upper Os0 Reservoir's ratio.
Mahr Reservoir, like the three Santa Rosa reservoirs, has almost no upstream
tributary watershed area.
I Feature
Tributary watershed area
Average water depth
Combined with other supplies
Nutrient removal at plants
Multiple port YO works
AeratiodDestratification
Chlorination of outflow
Other treatment of outflow
Basin lining and covering
General problem history
a), Estimated.
Sand
Canyon
Large
15" ft
No
Minorb
Yes
Yese
Yesg
Yesh
No
Yes
Rattle-
snake
Small
15" ft
Yes
Minorb
Yes
Nof
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
b)
c)
d)
e)
f)
g)
h)
i)
Partial nitrificatioddenitrification 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 ENGJNEERS IN ASSOCIATION wm JOHN POWELL & AsSWLATES
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
mi tigate 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 ASSOCIATION WITH JOHN POWELL & ASSOCIATES 1-6
31
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 CMWD’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 imgation 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 imgation period is assumed.
CGvL ENGINEERS IN ASSOCIATION wm Jom POWELL & ASSOCIATES 2- 1
34.-
Basis of Evaluation
Svstem Pipeline Criteria. System piping should be evaluated under all demand
conditions, but performance assessment is typically most critical under peak-hour
demand conditions. Generally, pipelines 12-inch and greater in diameter are
considered transmission pipelines. Because transmission pipelines impact large
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 where 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 admmistration 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 information.
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.
2-2 CGvL ENGINEERS IN ASSOCLATION WITH JOHN POWELL & ASSOCIATES
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 IN ASSOCIAT~ON 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:
(1) Current situation, representing an annual system demand of approximately
1,800 AFY
(2) Completion of Phase II, representing an annual system demand of
approximately 5,400 AFY
(3) Ultimate expansion, representing an annual system demand of approximately-
9,800 AFY
Three CMWD system scenarios were selected to quantify the reservoir’s benefit
at each milestone:
(A) System supply/demand 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
CGvL ENGINEERS IN ASSOCIATION Wm JOHN POWELL & ASSOCIATES’ 3- 1
Supply/Demand/Storage Analysis
adjusted average is shown in the last row of the same table.
adjusted peak-month factor of 2.10 is used for subsequent facility analysis.
The resulting
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 imgation cycles.
..
L. 0
2.50
2.00
1.50
1.00
0.50
0.00
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
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 WRJ?, 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
avaiZabZe 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 & ASSOCIATES I 3-2
37
Supply/Demand/Storage Analysis
Current
..
Phase I1 Ultimate
Supply Source
Carlsbad AWT
MGD AFM MGD AFM MGD AFM
0.00 I 0 4.00 I 374 15.0 I 1,401
MeadowlarkW I 1.70 I 159 I 2.00 I 187 I 3.0 I 280
Gafner WRP
Total
0.75 70 2.00 187 2.0 187
2.45 229 8 .OO 747 20.0 1.868
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, and 3C.
Milestone/
Scenario
1 - Current
A
B
C
A
B
C
3 - Ultimate
A B
C
2 - Phase II
A critical test for seasonal supply/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.
Peak-Month Volume, AFb Total
Required Supply From Storage Demand Carlsbad Meadow. Gafner Otherc Storage Volume, AF
315 0 150 0 0 165 548
3 15 0 159 70 86 0 0
315 0 159 70 16 70 15 1
945 374 76 0 0 495 1,644
945 374 187 187 198 0 0
945 374 187 187 62 136 15 1
1,716 8 17 0 0 0 899 2,983
1,716 1,40 1 280 35 0 0 0
1,716 1,40 1 164 0 0 151 151
a) Peak month assumed to be July, with a peak-to-average-month ratio of 2.10, based on Figure 3-1.
b) Because of round-off, sums of volumes may differ by k1 AF.
c) Other supply capacity assumed to be supplemented potable water.
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 & AssocrpiTEs 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. .
Milestone
Current
Phase II
Ultimate
Equivalent Fraction of
Peak-Month Peak-Month Full y-Balanced
Production Rate Storage
AF MGD percent
70 0.75 28
136 1.46 9
151 1.62 5
Supply
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 CMWD’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 sample 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:
CGvL ENGINEERS IN ASSOCIATION WlTH JOHN POWELL & ASSOCLATES 3 -4
39
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 correctly condition emergency storage availability,
so as not to inappropriately “double-count” Mahr Reservoir storage for both
seasonal and emergency purposes.
CGvL ENGINEERS IN ASSOCIATION WWH JOHN POWELL & ASSOCIATES 3-5
qo
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 andor
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
o Adding an aeratioddestratification system in the reservoir
o Adding chlorination to reservoir outflow
o Reusing existing microscreens, either at Meadowlark WFW or relocated to
Mahr Reservoir, to remove suspended material from reservoir outflow
o 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
part of secondary treatment at a wastewater treatment plant.
While Meadowlark WR.F 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 ~lu’ ASSOCIATION WITH JOHN POWELL & ASSOCIATES 4- 1
Facilitv 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 canddate improvement is not considered further.
Modified VO Works. The current reservoir I/O works has only one set of
openings around elevation 550 feet, only a few feet above the basin bottom. An
improved I/O 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 UO 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 I/O
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 I/O
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 I/O structure is shown on Figure 4-2. Four VO 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 I/O 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 Enciiza Basiiz Recycled Warer
Distribution 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 I/O piping and valves. Table 4-1 lists peak-hour withdrawal rates estimated
in the above-noted work for the Phase II 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 II to the ultimate condition. Hence, the estimated
CGvL ENGINEERS IN ASSOCIATION wm JOHN POWELL & ASSOCIATES 4-2
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Facilitv Alternatives
Phase II peak-hour withdrawal rate is higher than the ultimate rate, and the Phase
II rate should be used for I/O works sizing.
Because the runs are short, the existing 18-inch I/O 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.
I Parameter.
Peak-Hour Flow I gpm
Pipe Velocity I fPS
Based on Existing YO Pipeline Diameter (18 inches)b:
Based on Hydraulic Criteria Diameter (24 inches)b:
PiDe Velocitv I fns
a) Unit abbreviation: gpm = gallons per minute.
b) Using a friction factor of C = 120.
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 VO 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 photograph
of similar YO 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.
Aeratioflestratification System. 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 O’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.
,
CGvL ENGINEERS IN ASSOCLATION WITH JOHN POWELL &‘ASSOCIATES 4-5
Facilitv Alternatives
Upper two UO ports, looking east.
Figure 4-3 Upper Os0 Reservoir I/O Works
An aeration system can perfom 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
diffkser pipeline. usually located 5-10 feet above the bottom near the deepest
portion of the basin. Keeping this diffbser 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 I/O works valve
controls and the aeration/destratification 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.
I
Facility Alternatives
Concrete Vault
Excavation I
24-Inch Steel Pipe w/Epoxy Coating
1 %inch 90-degree Elbows w/Epoxy
24x24~ 1 &inch Tee wEpoxy Coating
Flexible Coupling
1 %inch BFV wl Hydraulic Cylinder
Stainless Steel Wire Screen
Hydraulic Accumulator System
Miscellaneous Metalwork
0
Contractor OH&P
Total Construction
a) b) Cost for January 2000.
Unit abbreviations: LS = lump sum; CY = cubic yard.
CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & AssoClA'r~s 4-7
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Facility Alternatives
Wide spot in access road, looking east over spillway.
Figure 4-4 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 diffiiser pipeline would
have small, appropriately-sized holes drilled approximately every' five feet for its
entire length. This pipeiine would be held in place. approximately parallel to the
reservoir bottom. by a series of anchors that resist the pipeline's tendency to rise
when charged with air. This type system has'been operating at SMWD's 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 generall!r 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 ENGINEERS M ASSOCIATION WITH JOHN POWELL & XSSOCI.4TES 4-8
Facilitv Alternatives
specifically for disinfection, this candidate improvement is not considered further.
It could be reconsidered for a future phase of work.
Outflow MicroscreeninP. 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 would 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 Coverinp. 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 mechanical] y-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 ENGINEERS IN ASSOCIATION WITH JOHN POWELL & AssOClATES 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 (HDPE)
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:
a A means to anchor the edge of the liner
a 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, Alternative 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 IN ASSOCIATION WITH JOHN POWELL & Assoc~~~~s 4-10
Facility Alternatives
Unit Cost
$1/SF
$1/SF
$25/LF
$4O/LF
$0.75/SF
$2.10/SF
$40/LF
LS
Itema
Porous AC Liner
Polypropylene Liner
Underdrain (in reservoir)
Underdrain (through embankment)
B aseb
Polypropylene Cover & Appurtenances'
Concrete Ringwall Appurtenances
Excavationd
Subtotal Construction
Contractor OH&P
Total Construction Contingency
Subtotal Project Engineering & Administration
Total Project
Total Cost, dollars'
Alternative A Alternative B
NIA 385,000
385,000 NIA
40,000 NIA
20,000 NIA
86,625 86,625
735,000 735,000
116,000 116,000
100,000 100,000
1,422,625 1,482,625
296,535 284,525
1,779,150 1,707,150
355.830 34 1,430
2,134,980 2,048,580
320.247 307.287
Quantity'
385,000
385,000
1,600
500
115,500
350,000
2,900
1
20 percent
20 percent
15 percent I 2,455,227 1 2355,867 I
a)
b)
c)
d)
e)
f) Cost for January 2000.
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), bortom 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, debrislsludge 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. u
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 IN ASSOCIATION WlTH JOHN POWELL & ASSOClATES 4-1 1
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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:
LI 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 ASSOCIATION WITH JOHN POWELL Sr A~SO~IATES 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 pnmary 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 IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES 4-13
s.3
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.
0
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 ASSOCUTION WITH JOHN POWELL & ASSOCIATES 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 cument condition, Mahr Reservoir’s volume is relatively small and would not
necessady take enough flow in the winter to save significant treated wastewater
disposal capacity in the ocean outfall system. Appropriate estimations of realistic
volumes would 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 .5-MG, above-ground, steel,
operational storage reservoir on a newly-purchased site; and 1.46-MGD additional
peak-month equivalent supply capacity (see Table 3-3), assumed as a marginal
increase to planned Carlsbad AWT expansion capacity. Table 5-1 shows
resulting capital costs by line item and totals.
CGvL ENGINEERS o\I ASSOCIATION WIT” JOHN POWELL 8: ASSOCLATES 5-2
Alternative Costs and Phasing
Unit Cost
lump sum
lump sum
lump sum
lump sum
lump sum
a
Alternative 1‘ Alternative 2g
150,000 NIA
289,000 NIA
166,000 NIA
1,423,000 NIA
175,000 NIA
Item I Ouantitv
Miscellaneous Site Worka
New Oper. Storage Res. Sitea
New Oper. Storage Res. Construction‘
Additional Peak-Month Plant Capacityd
Without Mahr Reservoir
Sub to tal Construction
With Mahr Reservoir
Dredging & Cleaninga
Modified I/O Worksa
AeratiodDestratification Systema
Lining and Coveringb
1
1 acre
1.5 MG
1.46 MGD
1
1
1
160 AF
Contractor OH&P
Total Construction
Contingency
Subtotal Project
20 percent
20 percent
Engineering & Administration I 15 percent
Total Project
lump sum
4 13,000
1,167,000
NIA
NIA
NIA
2,203,000
44 1,000
. 2,644,000
529,000
3,173,000
476,000
3,649,000
100,000
620,000
1,704,000
2,424,000
485,000 . 2,909,000
5 82,000
3,491,000
524.000
4,015,000
a) Preliminary estimate.
b) Cost based on lining and covering Alternative B.
c) Volume sized per final distribution system analysis.
d) 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 Recycliiig Facility.
e) 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.
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 1.62 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.
CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES 5-3
Alternative Costs and Phasina
I Item I Ouantitv
With Mahr Reservoir I Per Table 5-1
New Oper. Storage Res. Sitea
New Oper. Storage Res. Constructionb
Additional Peak-Month Plant Capacity'
Without Mahr Reservoir
Subtotal Construction
Contractor OH&P
Total Construction
Contingency
Subtotal Project
Engineering & Administration
Total Project
1
2 acres
3.5 MG
1.62 MGD
20 percent
20 percent
15 percent
a) Preliminary estimate.
b) Volume estimated from ratio of ultimate to Phase I1 demands.
c) Capacity based on Chapter 3 analysis, shown in Table 3-3; cost based on incremental capital improvements in Preliminary Design Repolt for the Carlsbad Water Recycling Faciliv.
d) 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.
e) Assumes Mahr Reservoir improved for use as operational and seasonal storage. 0 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 11 including all items except lining and covering, which would be deferred
as discussed in Chapter 4. These Phase 11 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 ASSOCIATION WITH JOHN POWELL & ASSOCIATES 5 -4
5-3
Alternative Costs and Phasing
Quantity
1
1
1
1
20 percent
20 percent
15 percent
I Item Unit Cost dollars
lump sum 150,OOo
lump sum 289,000
lump sum 166,000
lump sum 175,000
780,000
156,000
936,000
1 87,000
1,123,000
168,000
1,291,000
Dredging & Cleaning
Modified I/O Works
AerationDestratification System
Miscellaneous Site Work
Subtotal Construction
Contractor OH&P
Total Construction
Contingency
Subtotal Project
Engineering & Administration
’ Total Project
a) All entry notes same as for Table 5-1.
CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCMTES 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
common 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
Turbidity
Coliform
General Mineral
PH
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
Fre uenc
Monthly
Monthly
Monthly
Monthly
Monthly
Monthly r Monthly
Grab I TOD and Bottom I Ouarterlv
CGvL ENGINEERS IN ASSOCIATION Wm JOHN POWELL & ASSOCIA~S 6- 1
s'9
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 IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES 6-2
bo
Appendix A
HISTORICAL RECYCLED WATER DEMANDS
CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES A- 1
br
E:
0
-\= "p: oc
z
Y if
mo
hl
22
e, eD
e, 2
2 -
Appendix B
SEASONAL STORAGE MODEL RUNS
CGvL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & ASSOCIATES B-1
d3
Analysis of Monthly SupplylDemandlStorage Requirements
PROJECT. CMWD Recycled Water System Expansion
SCENARIO 1A: With Full Seasonal Storage
SUPPLY: RW4.61 mgd; Other=O mgd
QEMAND: Current Q 1,800 ac-Wyr
TORAGE: 0 ac-ft existing seasonal storage, 548 ac-ft required seasonal storage 1
~ Evapo- Seasonal
transpir., Precip., Variation
in in Ratio
n/a n/a 0.1 1
da n/a 0.16
n/a n/a 0.37
n/a n/a 0.82
n/a da 1.37
nla n/a 1.83
nla da 2.1 0
nla n/a 1.76
n/a nla . 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
Vlonth
Jan
Feb
Mar
APr
May
-
Jun
Jul
Aug
SeP oct
Nov
Dec
TOTAL
-_----_-
Project Other Tota I
Demand, Demand, Demand,
ac-ft ac-ft ac-ft
16 0 16
24 0 24
56 0 56
1 23 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
.______----_______--_______l_l_________-------------------------------------------.
- INPUT
a)
b) c)
d) e)
n/a = effectivehotal precipitation ratio (no unitsj
n/a = irrigation efficiency (no units)
1,800 = annual project irrigation demand (ac-fVyr)
2.45 = maximum recycled water supply available (mgd: 0.00 = maximum other water supply available (mgd;
f) 3.00 = maximum reservoir inflow allowed (rngd) 3.00 = maximum reservoir outflow allowed (mgd)
1,000 = maximum reservoir working storage available (ac-ft) g) 0
Monthly Supply I Demand
350 i
250
al al - Em
I
150 a -
s" 1w
50
0
Jan Fob Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Reser. Reser. Unused
ac-ft' ac-ft 9 ac-ft
Flow, Storage, RW Supp.
ac-ft e
RW
ac-ft
150 0 150
150 0 150
150 0 1 50
150 0 1 50
1 50 0 150
150 0 150
150 0 150
150 0 150
150 0 150
150 0 150
1 50 0 150
150 0 1 50
1,800 0 1,800
._____-_______------_________________I__-.
OUTPUT
2.10 = peak month factor (no units)
1,800 = annual total demand (ac-Wyr)
1.00 = total supply/demand ralio (no units;
Jul = maximum irrigation demand month
Jan = minimum irrigation demand month 1.61 = maximum RW supply used (mgd)
0.00 = maximum other supply used (mgd) 1.43 = maximum reservoir inflow used (mgd)
1.77 = maximum reservoir outflow used (mgd)
548 = maximum reservoir working storage used (ac-8)
n/a = irrigation application rate (Wyr)
Monthly Reservoir I Unused RW Supply
I
500
400
200
0
Jan Feb Mar Apr May Jun Jul Aup Sep Oct Nov Dec
Month
F:\Prqecls\Powell.2OACarltbad Ph 11.0O1 \ResewoiARevMoSDS ~ 1 A-Currenl ~31100
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 1 B: With No Seasonal Storage
SUPPLY: RW=2.45 mgd; Other=0.92 mgd
nEMAND: Current @ 1,800 ac-ft/yr
FORAGE: 0 ac-R existing seasonal storage, 0 ac-ft required seasonal storage
16 0 16
24 0 24
56 0 56
123 0 123
205 0 205
275 0 275
315 0 31 5
264 0 264
226 0 226
1 63 0 1 63
63 0 63
70 . 0 70
1,800 0 1,800
------------________-------------------------------------*-----------------------.
Month
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
SeP oct
Nov
Dec
TOTAL
-
_----_-
16 0 16
24 0 24
56 0 56
123 0 1 23
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
Evapo- Seasona
transpir., Precip., Variatior
in in Ratio
~~ ~~
da n/a 0.1 1
n/a n/a 0.16
n/a n/a 0.37
nla n/a 0.82
n/a n/a 1.37
n/a n/a 1.83
da nla 2.1 0
n/a n/a 1.76
n/a n/a 1.51
n/a nla 1.09
n/a n/a 0.42
n/a n/a 0.46
n/a n/a 12.00
__I__C--_---_--_---------------------.
- INPUT
Other Total
ac-ft
Project Other
Demand, Demand,
ac-ft ac-ft
OUTPUT
a) n/a = effectivehotal precipitation ratio (no units)
b) n/a = irrigation efficiency (no units) c) 1,800 = annual project irrigation demand (ac-tVyr) d) 2.45 = maximum recycled water supply available (mgd:
e) 1 .OO = maximum other water supply available (mgd:
f) 0.00 = maximum reservoir inflow allowed lmodl
0.00 = maximum reservoir outflow allowed (Ggd]
0 = maximum reservoir working storage available (ac-11)
Monthly Supply I Demand
350
I. I
Jan Fob Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Reser. Reser. Unused
Flow, Storage, RW Supp.
ac-tt ac-ftg ac-n
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
2.10 = peak month factor (no units)
n/a = imgation application rate (fVyr) 1,800 = annual total demand (ac-fUyr)
1 .OO = total supply/demand ratio (no units:
Jul = maximum irrigation demand month
Jan = minimum irrigation demand month 2.45 = maximum RW supply used (mgd)
0.92 = 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 (ac-ft)
i Monthly Reservoir I Unused RW Supply I I
I
I-Reser. i I I---l 1- Unused J
Jan Feb Mar Apr May Jun Jul Aug Sep Ocl Nov Oec
1 Month
F .\Prqecls\Powel1.207lCarlsbad Ph 11.001 \ReservoifiRevMoSDS - 18-Current 5/31/00
65
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 rngd; Othe~O.17 rngd
’)EMAND: Current 0 1,800 ac-Wyr
TORAGE: 0 ac-ft existing seasonal storage, 151 ac-R required seasonal storage
RW Other Total
Supply, Supply, Supply, ac-no ac-fie ac-n
I -
Month
Jan
Feb
Mar
APr
May
Jun
Jul
-
Aug
SeP
Oct
Nov
Dec
TOTAL
.--------
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
----------------------------------------------___-----------_--_-------------------.
Evapo- Seasona
tranopir., Precip., Variatior in in Ratio
nla n/a 0.1 1
da nfa 0.16
n/a n/a 0.37
n/a nfa 0.82
da nla 1.37
da nfa 1.83
nla n/a 2.1 0
n/a n/a 1.76
da nla 1.51
da nla 1.09
da n/a 0.42
da n/a 0.46
nta nla 12.00
.__I_C_--_________-_-----------------
92 0 92
100 0 1 00
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
- INPUT
n/a = effective/total precipitation ratio (no units)
nla = irrigation efficiency (no units)
1.800 annual project irrigation demand (ac-ftlyr)
2.45 = maximum recycled water supply available (rngd:
0.00 = maximum other water supply available (mgd: 3.00 = maximum reservoir inflow allowed (mgd)
3.00 = maximum reservoir outflow allowed (rngd)
151 = maximum reservoir working storage available (ac-ft)
Monthly Supply I Demand
350 ,
- 250
0) - $ 200
s” loo
a 5 150 -
50
0
Jan Feb Mar Apr May Jun Jul Aup Sep On Nov Dec
Month
2.10 nla
1,800
1 .oo
Jul
Jan 2.45
0.17
0.75 151
0.81
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) 1 05 0
(70) 35 0
(35) 0 0
0 0 3
0 0 65
0 0 1 66
0 0 159
(0) 962
.-------I---------C-_______I_________
= peak month factor (no units)
= irrigation application rate (ftlyr) = annual total demand (ac-ftlyr) = total supply/demand ratio (no units: = maximum irrigation demand month = minimum irrigation demand month = maximum RW supply used (mgd) = maximum other supply used (rngd) = maximurn reservoir inflow used (mgd) = maximum reservoir outflow used (mgd) = maximum reservoir working storage used (ac-ft)
Monthly Reservoir I Unused RW Supply
200 I
180
160 - 140
’ 120 e
a 1w ai
0 b
5 BO
g60
-
Month
F:\Projecis\PowelI.207’Carlsbad Ph Il.00l\ResewoiARevMoSDS ~ 1CCurrent 5/31 mo
Analysis of Monthly Supply/Demand/Storage Requirements
PROJECT CMWD Recycled Water System Expansion
SCENARIO 28: With No Seasonal Storage
SUPPLY: RW=8.00 mgd; Other=2.12 mgd
IEMAND: Phase II Q 5,400 ac-Wyr
TORAGE: 0 ac-ft existing seasonal storage, 0 ac-fi required seasonal storage
RW Other Total
Supply, Supply, Supply, ac-ft ' ac-ft e ac-ft
49 0 49
73 0 73
168 0 168
370 0 370
61 5 0 61 5
747 77 824
747 198 945
747 44 791
678 0 678
490 0 490
188 0 188
209 0 209
5,081 31 9 5,400
Vlonth
Reser. Reser. Unused
Flow, Storage, RW Supp.,
ac-ft' ac-ftg ac-ft
0 0 699
0 0 674
0 0 579
0 0 132
0 0 377 9
(0) (0) 0
(0) (0) 0
0 (0) 0
0 (0) 69
0 0 257
0 0 559
0 0 538
(0) 3,885
.--------------------------------------___________-___________________________
Evapo- Seasonal
transpir., Precip., Variation
in in Ratio
n/a n/a 0.1 1
n/a n/a 0.1 6 '
n/a 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 nla 1.51
n/a n/a 1.09
nla n/a 0.42
n/a n/a 0.46
n/a n/a 12.00
__-_-_----_------__-----------------
Project Other Total
Demand, Demand, Demand,
ac-ft ac-ft ac-ft
49 0 49
73 0 73
168 0 168
370 0 370
61 5 0 61 5
824 0 824
945 0 945
79 1 0 79 1
678 0 678
490 0 490
188 0 188
209 0 209
5,400 0 5,400
.-----------_-_------------------------------.
- INPUT
a)
b) c) 5.400 = annual project irrigation demand (ac-fUyr) . .
d) 8.00 = maximum recycled water supply available (mgd'
e) 2.00 = maximum other water supply available (mgd: 0.00 = maximum reservoir inflow allowed (mgd)
0.00 = maximum reservoir outflow allowed (mgd) f)
0 = maximum reservoir working storage available (ac-It)
n/a = effectivehotal precipitation ratio (no units)
n/a = irrigation efficiency (no units)
Monthly Supply I Demand
800 - 7M)
& 6M)
5M)
u -
b
0) s 400 - 0 'm
200
100
0
Jan Feb Mar Apr May Jun Jul AuQ Sep oct NW Dec
Month
OUTPUT
2.10 = peak month factor (no units)
5,400 = annual total demand (ac-Wyr)
1 .OO = total supply/demand ratio (no units;
Jul = maximum irrigation demand month Jan = minimum imgalion demand month
8.00 = maximum RW supply used (mgd) 2.12 = maximum other supply used (rngd]
0.00 = maximum reservoir inflow used (mgd)
0.00 = maximum reservoir outllow used (mgd)
0 = maximum reservoir working storage used (ac-It)
n/a = irrigation application rate (Wyr)
Monthly Reservoir I Unused RW Supply
700
500
400
300
200
Jan Feb Mar Apr May Jun Jul AUQ Sep Oa NW Dec
Month
F \Prqecls\PoweIl.ZO~Ca~sbad Ph II.WlWeservar\RevMoSDS - ZB-Phase I1 5AlK10
Analysis of Monthly Supply/Dernand/Storage Requirements
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 2C: With Mahr Reservoir Seasonal Storage SUPPLY: RW=8.00 mgd; Other=0.66 mgd
qEMAND: Phase I1 Q 5,400 ac-Wyr
TORAGE: 0 ac-ft existing seasonal storage, 151 ac-ft required seasonal storage
Evapo- Seasonal Project Other Total RW Other Total Reser. Reser. Unused
transpir., Precip., Variation Demand, Demand, Demand, Supply, Supply, Supply, Flow, Storage, RW Supp.
Month in in Ratio aC-ftC ac-tt ac-ft ac-ft' ac-ft * ac-tt ac-ft ' ac-tt ac-ft
Jan n/a nla 0.1 1 49 0 49 124 0 1 24 76 76 623
Feb nla nla 0.1 6 73 0 73 149 0 1 49 76 151 598
Mar nla nla 0.37 168 0 168 168 0 168 0 151 579
APr nla nla 0.82 370 0 370 370 0 370 0 151 377
May nla nla 1.37 61 5 0 615 61 5 0 61 5 0 151 132
Jun nla nla 1.83 824 0 824 747 62 809 (1 -3 136 0
Jul nla da 2.1 0 945 0 945 747 62 809 (136) (0) 0
Aug nla nla 1.76 791 0 791 747 44 79 1 0 0 0
Sep nla n/a 1.51 678 0 678 678 0 678 0 0 69
Oct nla nla 1.09 490 .o 490 490 0 490 0 0 257
Nov nla nla 0.42 188 0 1 88 1 88 0 188 0 0 559
Dec n/a nla 0.46 209 0 209 209 0 209 0 0 538
._---__----.-----------____--I-----------------------1--------1---------_------------------------_--_-_-_-_---_____-_--------------------------------------------------------------
ITOTALl n/a nla 12.00 I 5,400 0 5,400 I 5,232 168 5,400 I (0) 3.734
- INPUT
a)
b) c) d)
e)
f) 8.00 = maximum reservoir inflow allowed (mgd)
n/a I effective/total precipitation ratio (no units) n/a = irrigation efficiency (no units)
5,400 = annual project irrigation demand (ac-ft/yr) 8.00 P maximum recycled water supply available (mgd:
2.00 = maximum other water supply available (mgd;
8.00 = maximum reservoir outflow allowed (mgd)
151 = maximum reservoir working storage available (ac-tt)
Monthly Supply I Demand
1 .ooo
900 n
800 - 700
' 600 e
ai
0 -
p 500
f 400
3 300
-
200
100
0
Jan Feb Mar Agr May Jun Jul Aug Sep Ocl Nov Dec
Month
OUTPUT
2.10 = peak month factor (no units)
nla = irrigation application rate (fVyr) 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 (rngd)
0.66 = maximum other supply used (mgd) 0.81 = maximum reservoir inflow used (rngd)
1.46 = maximum reservoir outllow used (rngd) 151 = maximum resetvoir working storage used (ac-ft)
Monthly Reservoir I Unused RW Supply
700 , I I I
Jzn Feb Mar Apr May Jun Jul Aug Sep On Nov Dec
Month
F:\Prqects\PoweIl.Z07Carlsbad Ph II.Mll\ReseNoinRevMoSDS . 2C-Phase II 5/31/00
Analysis of Monthly Supply/Demand/Storage Requirements
Evapo- Seasonal
transpir., Precip., Variation
in in Ratio
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 3A With Full Seasonal Storage
SUPPLY: RW=8.74 mgd; Other=O mgd
qEMAND: Ultimate Q 9,800 ac-Wyr
Project Other Total
Demand, Demand, Demand,
ac-ftc ac-fl ac-ft
TORAGE: 0 ac-ft existing seasonal storage, 2,983 ac-ft required seasonal storage
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
889 0 889
341 0 341
379 0 379
9,800 0 9,800
-1
817 0 817 729 1,642 1,051
817 0 817 684 2,326 1,051
817 0 817 512 2,838 1,051
817 0 817 145 2,983 7,051
817 0 817 (299) 2,683 1,051
817 0 817 (679) 2,004 1,051
81 7 0 81 7 (899) 1,105 1,051
817 '0 817 (61 9) 486 1,051
817 0 817 (41 4) 73 1,051
817 0 817 (73) 0 1,051
81 7 0 817 476 476 1,051
817 0 817 438 914 1,051
9,800 0 9,800 0 12,613
.---------------_-__-----------------------___----_-_______________________________-----__--------_____-________________________--
I Month
1.m -
1.600 1
I
0 Demand I
Reser. Reser. Unused
ac-ft' ac-ftg ac-ft
Flow, Storage, RW Supp.,
RW
ac-ft ' ac-ft
n/a n/a 0.1 1
n/a n/a 0.16
nfa n/a 0.37
n/a n/a 0.82
n/a n/a 1.37
n/a n/a 1.83
nla nla 2.10
n/a n/a 1.76
n/a n/a 1.51
nta n/a 1.09
n/a n/a 0.42
n/a n/a 0.46
n/a n/a 12.00
_--_-_--_--_-__----_~------------------.
INPUT
a)
b)
c) d) 20.00 = maximum recycled water supply available (mgd:
e) 0.00 = maximum other water supply available (mgd:
f) 12.00 = maximum reservoir inflow allowed (mgd)
n/a I effectivdtotal precipitation ratio (no units)
da = irrigation efficiency (no units)
9,800 = annual project irrigation demand (ac-Wyr)
12.00 = maximum reservoir outilow allowed (mgd) g) 3,000 = maximum reservoir working storage available (ac-11)
OUTPUT
2.10 = peak month factor (no units)
n/a = irrigation application rate (ft/yr)
9,800 = annual total demand (ac-fVyr)
1 .OO = total supply/demand ratio (no units: Jul = maximum irrigation demand month
Jan = minimum irrigation demand month
8.74 = maximum RW supply used (mgd) 0.00 = maximum other supply used (mgd) 7.80 = maximum reservoir inflow used (mgd) 9.63 = maximum reservoir outflow used (rngd)
2,983 = maximum reservoir working storage used (ac-ft)
- 1.400
& 1.m 5
d
0 -
1,000
5 BOO - 0 ' 600
400
200
0
t ~rl II n 1 I
Jan Feb Mar Apr May Jun Jul Aug Sep oct NOV Dec I
Month I
Monthly Reservoir I Unused RW Supply
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
F:\Prqects\Powell.2O~Carlsbad Ph 11.001 \ReservoiARevMoSDS. 3A-Ultimate snimo
30
Analysis of Monthly Supply/Demand/Storage Requirements
I Evapo- Seasonal
transpir., Precip., Variation
in in Ratio
n/a n/a 0.1 1
n/a n/a 0.1 6
n/a 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 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
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 38: With No Seasonal Storage
SUPPLY: RW=18.37 mgd; Other=O mgd
qEMAND: Ultimate Q 9,800 ac-Wyr
‘ORAGE: 0 ac-ft existing seasonal storage, 0 ac-ft required seasonal storage
Project Other Total
Demand, Demand, Demand,
ac-ft ac-fl ac-ft
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
889 0 889
34 1 0 34 1
379 0 379
9,800 0 9.800
___________________________I____________-----------------------------------------------.
Month
Jan
Feb
Mar
APf
May
Jun
Jul
Aug
SeP
Oct
Nov
Dec
TOTAL
I :: : 1.600
-3 ! 0 Demand m 1, I msupply I
a)
b)
c) d) 20.00 = maximum recycled water supply available (mgd:
e) 0.00 = maximum other water supply available (mgd:
f) 0.00 = maximum reservoir inflow allowed (mgd)
n/a 5: effective/tofal precipitation ratio (no units)
n/a = irrigation efficiency (no units) 9,800 = annual project irrigation demand (ac-ft/yr)
0.00 = maximum reservoir outflow allowed (rngd)
0 = maximum reservoir working storage available (ac-ft)
Monthly Supply / Demand i
~~
Other Total
ac-fl ac-tt ac-tt
RW
SUPPI? Supplp Supply,
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
Reser. Reser. Unused
Flow, Storage, RW Supp.
ac-fl’ ac-ftg ac-ft
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1,780
1,735
1,563
1,196
752
372
152
432
638
979
1,527
1,489
0 12,613
OUTPUT
2.10 = peak month factor (no units)
n/a = irrigation application rate (Wyr)
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
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 (ac-fl)
Monthly Reservoir I Unused RW Supply I I
2.000 -
- 1,400 .- - - - - -
Jan Feb Mar Apr May Jun Jul Aup ,Sep Ocl NW Dec
Month
~
F:\ProjectS\POwell.20Aarlslmd Ph 11.001\Reservoir\RevMoSDS .JB-Ultimate mimo
71
Evapo- Seasonal Project Other Total RW Other Total Reser. Reser. Unused
transpir., Precip., Variation Demand, Demand, Demand, Supply, Supply, Supply, Flow, Storage, RW Supp., Month in in Ratio BC-fl' ac-fl ac-n ac-fla ac-ft ac-ft ac-fl' ac-ftg ac-ft
Jan nia da 0.1 1 88 0 88 164 0 164 76 76 1,704
Feb n/a n/a 0.1 6 133 0 133 208 0 208 76 151 1,659
Mar nia n/a 0.37 304 0 304 304 0 304 0 151 1,563
Apr n/a n/a 0.82 672 0 672 672 0 672 0 151 1,196
May nia nla 1.37 1,116 0 1,116 1,116 0 1,116 0 151 752
Jun n/a n/a 1.83 1,496 0 1,496 1,496 0 1,496 0 151 372
Jul nla nla 2.1 0 1,716 0 1,716 1,565 0 1,565 (1 51) 0 303
Aug n/a nla 1.76 1,436 0 1,436 1,436 0 1,436 0 0 432
SeP n/a n/a 1.51 1,230 0 1,230 1,230 0 1,230 0 0 638
Oct n/a n/a 1.09 889 0 889 889 0 889 0 0 979
Nov n/a n/a 0.42 341 0 341 341 0 341 0 0 1,527
Dec nla nl a 0.46 379 0 379 379 0 379 0 0 1,489
lT0TAL.l n/a n/a 12.00 I 9,800 0 9,800 I 9,800 0 9,800 0 12.613
___------_-._-_-__----I_-_____-_-----------------------------------------______I_____________------.__________________I_______________--________________________________________-
- INPUT
a)
b) c)
d) e) 0.00 = maximum other water supply available (mgd:
1) 3.00 = maximum reservoir inflow allowed (rngd)
nfa = effectire/total precipitation ratio (no units:
n/a = irrigation efficiency (no units)
9,800 = annual project irrigation demand (ac-Wyr] 20.00 = maximum recycled water supply available (mgd:
3.00 = maximum reservoir outflow allowed (rngd)
151 = maximum reservoir working storage available (ac-R)
1
OUTPUT
2.1 0 = peak month factor (no units)
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
16.76 = maximum RW supply used (mgd)
0.00 = maximum 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)
n/a = irrigation application rate (fvyr)
2.000
1 .Bo3
1.600 - 1,400 g 7 1.200
m- 1.000 5
s 800
al - 0
>6M)
400
200
0
Monthly Supply 1 Demand
Jan Feb Mar Apr May Jun Jul Aug Sep oct NW Oec
Month
Monthly Reservoir I Unused RW Supply
1.800 1 1
-- -! --
. Jan Feb Mar Apr May Jun Jul Aug Sep On NW Dec
Month
F:\Prqects\Pwell.2O~Carlsbad Ph II Wl\fiesewdrFievMoSDS~ 3C-Ullimate
Appendix C
EMERGENCY STORAGE MODEL RUNS
CGVL ENGINEERS IN ASSOCIATION WITH JOHN POWELL & AsSOClATES c- 1
Analysis of Monthly Supply/Demand/Storage Requirements
49 0 49
73 0 73
168 0 168
370 0 370
615 0 615
824 0 824
945 0 945
791 0 791
678 0 678
490 0 490
188 0 1 88
209 0 209
5,400 0 5,400
.-------------------___________________I-----_---_---_-_-I--_-____________I_____.
' 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; Otherz0.66 rngd
QEMAND: Current 0 5,400 ac-Wyr
TORAGE: 0 ac-ft existing seasonal storage, 151 ac-ft required seasonal storage
124 0 124
0 0 0
31 7 0 317
370 0 370
61 5 0 615
747 62 809
747 62 a09
747 44 791
678 0 678
490 0 490
1 88 0 1 88
209 0 209
5,232 1 68 5,400
Month
Jan
Feb
Mar
Apr
May Jun
Jul
Aug
SeP Oct
Nov
Dec
TOTAL
.--------.
Evapo- Seasona
transpir., Precip., Variation
in in Ratio
n/a
n/a
nia
nia
nia nia
n/a
nia
nia nia
n/a
n/a
n/a 0.1 1
n/a 0.16
nia 0.37
n/a 0.82
n/a 1.37
nia 1.83
nla 2.1 0
n/a 1.76
nia 1.51
n/a 1.09 n/a 0.42
nia 0.46
nia nia 12.00
- INPUT
Other Total
ac-n ' ac-ft ac-ft I ac-no RW ac-n ac-ft
Project Other
Demand, Demand, Demand, Supply, Suppl~ Supply,
a1
b) c)
d) e)
f)
n/a = effective/total precipitation ratio (no units)
n/a I irrigation efficiency (no units)
5,400 = annual project irrigation demand (ac-ft/yr)
8.00 = maximum recycled water supply available (mgd:
2.00 = maximum other water supply available (mgd:
8.00 = maximum reservoir inflow allowed (mgd)
8.00 = maximum reservoir outflow allowed (mgd)
9) 151 = maximum reservoir working storage available (ac-ft)
Monthly Supply I Demand
1.m -0 I I 900 i Demand
600
700
Mx)
500
4M)
300
200
100
Jan Feb Mar Apr May Jun Jul Aug Sep On Nov Dec
Month
OUTPUT
Reser. Reser. Unused
Flow, Storage, RW Supp.
ac-ft' ac-ftg ac-ft
2.10 = peak month factor (no units) '
ria = irrigation application rate (ftlyr)
5,400 = annual total demand (ac-Wyr) 1 .OO = 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]
1.60 = maximum reservoir inflow used (rngd)
1.46 = maximum reservoir outflow used (mgd)
151 = maximum reservoir working storage used (ac-ft)
Monthly Reservoir I Unused RW Supply
Jan Feb Mar Apr May Jun Jul Aug Sep Oct NO^ Dec
Month
F~\Prqects\Powell.2OT\Carlsbad Ph 11.001\Resew(ur\RevMoSDS - 20-FebEmerg
~~
Evapo- Seasonal
transpir., Precip., Variation
Month in in Ratio
Jan n/a n/a 0.1 1
Feb n/a n/a 0.16
Mar n/a n/a 0.37
Apr n/a nla 0.82
May n/a n/a 1.37
Jun n/a n/a 1.83
Jul nla nla 2.1 0
Aug nla nla 1.76
SeP n/a n/a 1.51
Oct n/a nla 1.09
Nov n/a nla 0.42
Dec n/a n/a 0.46
TOTAL n/a n/a 12.00
Reser. Reser. Unused
Flow, Storage, RW Supp
ac-ft ' ac-ftg ac-tt
Project Other Total RW Other Total
Demand, Demand, Demand, Supply, Supply, Supply, ac-ft' ac-ft ac-ft ac-ft" ac-ft' ac-ft
49 0 49 124 0 124
73 0 73 149 0 149
1 68 0 168 17 0 17
370 0 370 521 0 521
615 0 61 5 615 0 61 5
824 0 824 747 62 809
945 0 945 747 62 809
791 0 791 747 44 79 1
490 0 490 490 0 490
188 0 188 188 0 188
209 0 209 209 0 209
5,400 0 5,400 5,232 168 5,400
678 0 678 678 0 678
.---------.--------_--_--_-----_________________I__----------------------------------------------------------------------------------------
76
76
151
0
(151)
(15)
(1 36)
0
0
0
0
0
76
151
0
151
151
136
(0)
(0)
(0)
0
0
0
623
598
730
226
132
0
0
0
69
257
559
538
(0) 3,734
INPUT -
a)
b)
c) d) e)
f)
rda = effective/total precipitation ratio (no units)
rda = irrigation efficiency (no units) 5,400 = annual project irrigation demand (ac-ftlyr] 8.00 = maximum recycled water supply available (mgd'
2.00 = maximurn other water supply available (mgd: 8.00 = maximurn reservoir inflow allowed (mgd)
8.00 = maximum reservoir outflow allowed (rngd)
151 = maximum reservoir working storage available (ac-ft)
I Monthly Supply 1 Demand I
900
800 - 700
n 600 e : 500
0) -
01
400 - 0
2. 300
200
100
0
i
Jan Feb Mar Apr May Jun Jul AuQ Sep Od Nov Dec
Month I
OUTPUT
2.1 0 = peak month factor (no units)
5,400 = annual total demand (ac-ftlyr) 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 (rngd)
1.61 = maximum reservoir inflow used (mgd)
1.61 = maximum reservoir outflow used (rngd) 151 = maximum reservoir working storage used (ac-ft) . .
n/a = irrigation application rate (ft/yr)
- e 500
400
e
u 5 300 P
200 I
0 1.
Jan Fet Mar Apr May Jun Jul Aug Sep oct Nw Dec
Month
F \Pqects\Powe11.20ACarlsbad Ph II OOI\Resefvat'sRevMoSDS . PD-MarEmerg
Analysis of Monthly Supply/Demand/Storage Requirements
blonth
PROJECT: CMWD Recycled Water System Expansion
SCENARIO 2D: With Mahr Reservoir Seasonal and Emergency Storage SUPPLY: RW=8.00 rngd with loss of 131 ac-ft in April; Other=0.66 rngd
TEMAND: Current 0 5,400 ac-ft/yr
TORAGE: 0 ac-ft existing seasonal storage, 151 ac-ft required seasonal storage
Evapo- Seasona
transpir., Precip., Variatior
in in Ratio
Jan
Feb
Mar
Apr
Jun
Jul
Aug
SeP Oct
Nov
Dec
rOTAL
May
da n/a 0.7 1
n/a n/a 0.1 6
n/a n/a 0.37
, n/a n/a 0.82
n/a n/a 1.37
n/a n/a 1.83
n/a n/a 2.1 0
n/a n/a 1.76
n/a n/a 1.51
n/a n/a 1.09
n/a n/a 0.42
n/a nla 0.46
n/a nla 12.00
_____I__.___________________-----------------------
Project Other Total
Demand, Demand, Demand,
ac-ft ac-ft ac-tt
- INPUT
a)
b)
d) e)
nla = effective/total precipitation ratio (no units)
n/a = irrigation efliciency (no units) . c) 5,400 = annual project irrigation demand (ac-tffyr) 8.00 = maximum recycled water supply available (mgd:
2.00 = maximum other water supply available (mgd; 8.00 = maximum reservoir inflow allowed (mgd)
8.00 = maximum reservoir outflow allowed (mgd) 151 = maximum reservoir working storage available (ac-ft)
f)
Monthly Supply / Demand
1.m 1 n 900
800 - 700
'600 e
cn 500 s
0 c
s 400 - 0
>300
200
100
0
Jan Feb Mar Apr May Jun Jul Aug Sep Ocl Nov Dec
Month
~
RW Other Total
ac-tt a ac-fi ac-tt
Supply, Supply, Supply,
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
188 0 1 88
209 0 209
5,232 1 68 5,400
-----I------_-_-----------------------.
OUTPUT
Reser. Reser. Unused
Flow, Storage, RW Supp.
ac-ft ' ac-ftg ac-ft
76 76 623
76 151 598
0 151 579
(1 31 1 20 508
132 151 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
.----------------__-------------------
2.10 = peak month factor (no units)
1 .OO = total supply/demand ratio (no units:
Jul = maximum irrigation demand month Jan = minimum irrigalion 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 (ac-R)
n/a = irrigation application rate (tVyr)
5,400 = annual total demand (ac-tUyr)
Monthly Reservoir I Unused RW Supply
700 I
500 I u - i 400
Jan Feb Mar Apr May Jun Jul Aug Sep Oc1 Nov Dec
Month
F\Projects\PowelI.ZOACarlsbad Ph 11.001\ResewoiARevMSDS . 20-AprEmerp 5/31/00
3b
DISTRICT OLIVENHAIN MUNICIPAL WATER
HAHR RESERVOIR
PROPOSED CHWD 12- RECLAIMED WATER LINE
77
EXHIBIT C
Method of Calculating Recycled Water Rate
Pre-Exp-ual Cost (1) FY 2002103 Allocated to h4RF Tertiary Facilities
MRF Plant Costs Budget Percent Amount
Labor $ 2 10,000 25.0% $ 52,500
Other operating costs 43,000 50.0% 21,500
Materials 740,000 9.6% 7 1,040 Power 225,000 25.0% 56,250
Lift Station No. 1 60,000 100.0% 60,000 Mahr Reservoir 17,000 100.0% 17,000 Capital Recovery 110,926
Overhead - Wastewater Department $ 445,000 9.0% 40,050 Overhead - District Wide 3,658,000 1.9% 69,502
498.138
4
Total Annual Costs to Recover
Quarterly Payments i
Total Quarterly Payment due to VALLECITOS -
Ilotes:
~ ~~
Original or Anticipated Allocated to MRF Tertiary
Actual Costs Annual Costs Percent Amount
Post-Expansion Facilities Post-Expansion Annu a1 Cost (1)
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
$ 613,821
1 58,04 1
155,602
2 19,84 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%
9.6%
25.0%
50.0%
00.0%
00.0%
9.0%
1.9%
00.0%
00.0%
00.0%
00.0%
00.0%
00.0%
00.0%
00.0%
$ 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 Number of months per year - 12
Total Monthly Payment due to VALLECITOS $ 66.027
Annual costs shall be set each year based on budgeted amounts and retrospectively adjusted to audited amounts after year-end as described
in Section 13 of the agreement.
MRF Plant Costs - 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. (Le., 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 costs” include
miscellaneous items such as telemetry, telephone lines, minor repairs, etc.
Vallecitos’ actual costs of expansion design; filtration plant and disinfection facilities shall be used, when calculating capital recovery.
Vallecitos’ 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 inledoutlet piping through the reservoir, leakage recovery piping, and fencing, access road
and overflow facilities only. The existing dam drainage pump back system and inlet/outlet facilities will be replaced with new facilities
identified in Exhibit “B”.