HomeMy WebLinkAbout2021-01-28; Recycled Water Phase Ill Pipeline Expansion Segment 5 Project Update (Districts 1 & 2).; Gomez, PazTo the members of the:
CITY COUNCIL
Date 1/;;;(J/a,J CA v CC ✓
CM-~-ACM _y_ DCM (3) ✓
Jan.28,2021
CMWD Board Memorandum
To: Carlsbad Municipal Wat Dist ict Board of Directors
From: Paz Gomez, Deputy City Man
Vicki Quiram, General Managc:ICI.-F-":
Via: Scott Chadwick, Executive ~an · e
Ccarlsbad
Municipal Water District
Memo ID #2021024
Re: Recycled Water Phase Ill Pip'eli.ne xpansion Segment 5 Project Update (Districts 1 & 2)
This memorandum provides an update to a previous CMWD Board Memorandum dated
Oct. 15, 2020 on status of the Recycled Water Phase Ill Pipeline Expansion Segment 5 Project.
Background
Carlsbad Municipal Water District (CMWD)'s Recycled Water Phase Ill Pipeline Expansion
Segment 5 Project (Project) is comprised of six recycled water pipeline segments (Segments 2, 5-
1, 5-3 and 7) and two potable water replacement segments (in the Flower Fields and Carlsbad
Palisades subdivisions) located in Council Districts 1 and 2. As a part of the Segment 2 scope of
work, the Project requires a trenchless, jack-and-bore operation to facilitate the installation of a
30-inch casing for an 8-inch recycled water carrier pipe below the railroad tracks on Cannon
Road.
On Oct. 15, 2020, staff provided a Project update (Attachment A).
Discussion
On Dec. 29, 2020, while performing a 30-inch diameter jack-and-bore operation, Golden State
Boring & Pipe Jacking, Inc. (GSB), subcontractor to the city's prime contractor Ferreira
Construction Company, Inc. (FCC), struck, but did not rupture, an unknown utility beneath the
North County District Transit District (NCTD) railroad tracks near Cannon Road. While the identity
of the line was initially unknown, subsequent investigation revealed that the utility was a 30-inch
reinforced concrete storm drain pipe owned by the city, which was incorrectly mapped on the
construction drawing.
The obstruction created by the existing storm drain pipe requires abandonment of the current
jack-and-bore installation. Removal of the casing and hydraulic steering head at the leading end
of the equipment would leave an unsupported excavation that could potentially trigger
settlement at the ground surface above. As the potential for settlement within the roadway and
railroad track is unacceptable, staff directed the contractor to complete the abandonment of the
jack-and-bore operation by withdrawing the augers and pumping concrete into the steel casing,
leaving the steering head inside the casing.
Carlsbad Municipal Water District
5950 El Camino Real I Carlsbad, CA 92008 I 760-438-2722 t
Board Memo -Recycled Water Phase Ill Pipeline Expansion Segment 5 Project Update (Districts 1 & 2)
Jan.28,2021
Page 2
Trenchless Construction Options
On Dec. 31, 2020, staff initiated discussions with the Project engineering consultant for an
alternative trench less alignment and met again in early January 2021 to discuss alternative
design approaches to complete the installation. On Jan. 7, 2021, staff met with the engineering
consultant and contractor team to discuss the feasibility of two options for a second attempt at
completing the jack-and-bore beneath the railroad tracks:
• Option l: Lower the elevation of the jack-and-bore approximately four feet to allow the
new 30-inch casing to cross under the conflicting storm drain line. This option has
potential risks since a deeper installation would likely encounter groundwater in the
jacking pit and possibly in the auger boring alignment, triggering the potential for caving
or running sand in the bore and the potential need for a more complicated boring
operation with different equipment.
• Option 2: Maintain the elevation of the jack-and-bore but revise the horizontal (lateral)
alignment to clear the storm drain line. While this option would not likely encounter
groundwater, it would require installation of new jacking and receiving pits as well as
additional field investigation via potholing, re-design and permitting with NCTD.
Additionally, the most viable alignment presented with Option 2 would likely require the
closure of Cannon Road for a period of two weeks. This option also carries the risk of
potentially encountering other unforeseen or unexpected utilities while installing the
30-inch casing in a tight corridor that is heavily congested with many utilities.
The cost to complete the original Segment 2 scope of work was $661,281. With some of the
original scope of work completed (approximately 1,000-feet of 8-inch recycled water pipeline
partially constructed and backfilled which could be used for recycled water in the future), and
most of the jack-and-bore work effort completed prior to encountering the storm drain line, staff
estimates little to no credit back for work not performed against this bid item.
Staff estimates the cost of a jack-and-bore operation using Option 2 to be approximately
$500,000. Staff does not have an estimate from the contractor for Option 1; however, due to the
risk of managing groundwater, it is likely to be greater than Option 2. Due to the impact, staff
estimates the total cost to complete the Segment 2 recycled water installation at approximately
$1.2 million.
Recycled Water Demand
Recycled water customers served by Segment 2 consist of Cannon Park (city leases from San
Diego Gas and Electric (SDG&E), located at the intersection of Cannon Road and Carlsbad
Boulevard) and Cabrillo Power I LLC, a subsidiary of NRG.
• The total recycled water market demand for Phase Ill (Segments 2, 5-1, 5-3 and 7) is
approximately 180 acre-feet (AF).
Board Memo -Recycled Water Phase Ill Pipeline Expansion Segment 5 Project Update (Districts 1 & 2)
Jan. 28,2021
Page 3
• NRG's recycled water demand is estimated at approximately 85 AF per year. NRG is
currently supplied with recycled water by an interim connection to an existing pipeline in
Avenida Encinas, north of Cannon Road, which was previously constructed as part of the
Agua Hedionda Uft Station and Force Main Project. Staff believes the interim connection
can be perpetuated in a less costly trench less installation north of Cannon Road.
• The estimated demand for Cannon Park is less than 5 AF per year (2.6% of the total for
Phase Ill) and will have an annual market billing of approximately $7,400 at current
recycled water rates. The park is currently irrigated by potable water. Assuming a cost to
complete Segment 2 of $1.2 million, an estimate of the payback period for serving only
Cannon Park is well over 100 years.
The long-term development plan for the NRG property and any future associated recycled water
demand are currently unknown.
Staff Recommendation
The anticipated revenues from all known recycled water customers served by Segment 2 do not
warrant the additional cost to complete Segment 2 using either Option 1 or 2. Staff has therefore
determined that work on Segment 2 should be cancelled and the site secured and restored,
which will complete the Recycled Water Phase Ill Project.
Next Steps
Staff will negotiate with the contractor to descope the rest of the Segment 2 work and execute
any change orders necessary to complete the Project.
Attachment: A. CMWD Board Memorandum dated Oct. 15, 2020
cc: Scott Chadwick, Executive Manager
Celia Brewer, General Counsel
Robby Contreras, Assistant General Counsel
Dave Padilla, District Engineer
Babaq Taj, Engineering Manager
To the members of the:
CITY COUNCIL
Date '0/2 s /-:J.D CA ...£.. CC ✓
CM _y_ ACM V DCM (3) L
Oct. 15, 2020
ATTACHMENT A
CMWD Board Memorandum ·'\ ( \
To: Carlsbad Municipal Wa;~r Jistric; Board of Directors
Vicki Quiram, General Man1 ger \ -"" From: .,
Via: Scott Chadwick, Executive M~rl~ger
Ccarlsbad
Municipal Water District
Memo ID #2020225
Re : Recycled Water Phase Ill Pipeline Expansion Segment 5 Project Update
This memorandum provides an update on the status of the Recycled Water Phase Ill Pipeline
Expansion Segment 5, Capital Improvement Program (CIP) Project No. 5208-B and the
Miscellaneous Pipeline Replacements, CIP Project No. 3904 (Project).
Background
The Project is part of the Carlsbad Municipal Water District's (CMWD) $37 million Phase Ill
Recycled Water Program (Program). Awarded in October 2018 with a construction contract
valued at $9,487,655, the Project requires installation of approximately 37,000 linear feet
(approximately 7 miles) of recycled and potable water pipeline. It includes construction of
recycled water pipelines along Tamarack Avenue, Kelly Drive, Marron Road, Haymar Drive,
El Camino Real and Cannon Road, as shown in the attached map. The Project will also upgrade
existing potable water mains within the Carlsbad Palisades and Flower Fields Home Owner
Associations to current CMWD standards.
Discussion
Following a post-award, preconstruction potholing effort by the contractor, staff identified a
significant number of impacts to the proposed pipeline alignment(s) due to unanticipated and
previously unidentified buried utilities. On Dec. 17, 2019, the CMWD Board authorized
additional funding for the Project in the amount of $3,141,697 to iricorporate new scope of
work items that addressed unanticipated impacts.
Since the last project update, Public Works Branch, Construction Management & Inspection
Department, and CMWD staff have diligently worked with Ferreira Coastal Construction
Company (Contractor) to complete the Project within the revised budget and time constraints.
As of Sept. 1, 2020, the Prnject was approximately 60% complete.
Staff anticipates completion of the Project in spring 2021, which will result in delivery of
approximately 180 acre-feet of recycled water per year to CMWD's customers -a significant
milestone in the Program's goal to cost-effectively reduce demand on the potable water
system.
Carlsbad Municipal Water District
5950 El Camino Real I Carlsbad, CA 92008 I 760-438-2722 t
I
I·
I
CMWD Board Memo -Recycled Water Phase Ill Pipeline Expansion Segment 5 Project Update
Oct. 15, 2020
Page 2
Next Steps
Staff will continue to work with the. Contractor to complete the Project within the contract
terms and an estimated completion date of spring 2021. Staff will also provide awareness
notifications and construction activity updates to the neighborhoods closest to the
· construction activities to minimize potential impacts. At this time, staff does not anticipate a
need for additional funds on this Project.
Attachment: A. Project location map
cc: Geoff Patnoe, Assistant Executive Manager
Celia Brewer, General Counsel
Robby Contreras, Assistant General Counsel
Paz Gomez, Deputy City Manager, Public Works
Babaq Taj, Engineering Manager
David Padilla, Interim District Engineer
LOCATION MAP
NOT TO SCALE
PROJECT NAME RECYCLED WATER PHASE Ill
PIPELINE EXPANSION SEGMENT 5
01 nnrn cv. e-NlTT C'l/AllC OJf"IT nAtr,1?1f7/t .. OAn.l,n,\11n1,nc-e 1\CDADTIIOJT\1,ir1.n1UJ UAOC\.tllTIV'An\~?nGD C'C'CIJrllT 1.n~ • --• _,,, .... ,._, ••, o o • ,,,,,._, \-••-•·----• OHoU••-•• • •-••••-•• m,., -\••-•--••-,-------"•-••--•-••-
Attachment A
PROJECT NUMBER
5208-B