ITEM:

CONSENT CALENDAR

 

2.

CONSIDER EXPENDITURE OF FUNDS FOR CONSULTANT SERVICES FOR UPGRADES AT THE SLEEPY HOLLOW STEELHEAD REARING FACILITY

 

Meeting Date:

August 16, 2021

Budgeted: 

Yes

 

From:

David J. Stoldt,

General Manager

Program/

Protect Environmental

Quality

 

 

Line Item No.: 

2-3-1-O

 

Prepared By:                  

Thomas Christensen and

Larry Hampson

Cost Estimate: 

$ 67,500

 

General Counsel Review:  N/A

Committee Recommendation:  The Administrative Committee reviewed this item on August 9, 2021 and recommended approval.

CEQA Compliance:  Exempt under §15262.

 

SUMMARY:  Staff proposes to retain Tetra Tech to assist with preparation of plans, specifications, and a cost estimate for completing maintenance work to the Sleepy Hollow Steelhead Rearing Facility (SHSRF or Facility).  Although recent upgrades were completed to improve the reliability and quality of the water supply for the facility, other portions of the facility including the rearing channel liner, quarantine tanks, and refrigeration systems have reached their end-of-life cycles and need maintenance and upgrades.

 

Staff requested proposals from four consulting firms.  Two (Tetra Tech and Harris and Associates) responded with proposals (Exhibits 2-A and 2-B).  Both consulting firms have the needed expertise and understanding of services required and provided similar scopes of work.  Tetra Tech has considerable experience with design and construction at the Facility and their proposal was about $34,000 less than the Harris and Associates proposal.

 

Tetra Tech proposal is a lump sum, percentage of effort (i.e., each task would be billed on a percentage completed up to 100% for each item).

 

RECOMMENDATION:  The Administrative Committee recommends that the Board authorize the General Manager to enter into an agreement with Tetra Tech for consultant services in an amount not-to-exceed $61,338 and approve a 10% contingency (approximately $6,100) for additional consultant work.

 

DISCUSSION:  The Sleepy Hollow Steelhead Rearing Facility was constructed in 1996 and was intended at the time to be a short-term mitigation activity for impacts to Carmel River steelhead from diverting Carmel River flows until a new water supply was built.  Recent upgrades to the facility were designed to improve the reliability and quality of the water supply after the removal of San Clemente Dam led to an increase in fine sediment in the Facility’s water supply.  However, the upgrades did not address other components at the facility that have reached or exceeded their life expectancy.

 

Staff proposes to carry out replacement of portions of the Hypalon liner used to prevent water from leaking out of the rearing channel.  The liner, which has a life expectancy of less than 20 years, has deteriorated, leaks in several areas, and needs replacement.[1] 

 

While the entire liner should eventually be replaced, staff is proposing to replace only the liner in 16 of the 17 pools in the rearing channel (one pool liner was recently replaced).  Cobbles originally installed in the pools in 1996 to mimic natural habitat have been removed, which simplifies the removal of the existing liner and reinstallation of a new liner.  Work to replace this portion of the liner would be carried out in the winter of 2021-22.  Staff may replace the liner in the remainder of the channel as a separate project in the future. 

 

In addition to the channel work proposed for the upcoming winter, five fiberglass tanks used for quarantine purposes are cracked and/or the bases supporting the tanks are deteriorating.  These would be replaced and refrigeration units for the tanks would be removed and replaced.  The existing chillers are more than 20 years old and chiller technology has advanced significantly since the original installation.  New chiller technology includes the use of variable-speed drives, an evolution in control hardware, software, and sensors that have led to improvements in industrial chiller reliability, accuracy, and energy efficiency.  Staff is also considering centralization of  refrigeration into one unit that can quickly cool individual tanks or be used to cool specific portions of the rearing channel when water temperatures are too high.

 

Project construction work, which will be subject to future bid processes, consists of:

 

Rearing channel pool maintenance (16 total):

 

•                        Remove existing Hypalon liner in each pool

•                        Excavate and dispose on site of approximately 6 inches of native material under the pools

•                        Shape pool to drain

•                        Pour steel reinforced waterproof concrete slab (e.g., add Xypex to the concrete mix); integrate into existing rearing channel concrete walls; work would require inspection for rebar and concrete testing (minimum 4,000 psi concrete)

•                        Install new liner and integrate existing liner with new pool configuration at upstream and downstream edges of the pool

•                        Repair top boards on rearing channel walls (if required)

•                        Fill rearing channel and inspect for water leakage

The plan set would include a site plan, typical sections, and details of the rearing channel pool and rebar configuration.  Specifications would include concrete strength, rebar size, concrete additives, and liner specifications. There may be a need for a shoring design for the existing walls during excavation and concrete pouring.  Approximately 6 inches of material will be removed from under the existing pool walls, which are 18 inches thick at the base and 10 inches thick at the top.  Symmetrical pools may not require shoring; however, non-symmetrical pools may need temporary supports across the tops of the pool.  

 

Quarantine Tanks (5 total)

•                        Remove and salvage decking

•                        Cut plumbing (air, water, drain); disconnect electrical service and monitoring cables

•                        Remove and dispose existing quarantine tanks

•                        Remove existing chillers and replace with individual chillers or a centralized unit  capable of lowering water temperature up to approximately 10 degrees (TBD through calculation)

•                        Excavate and dispose native material under the existing tanks (depth TBD)

•                        Determine adequacy of native fill and import, compact, and test new base material as required

•                        Pour steel reinforced, waterproof concrete slab

•                        Build new steel or aluminum support frames and reset tanks; connect plumbing, air, electrical, drains, and monitoring cables above the decking or in an easily accessible “critter-proof” box

•                        Reinstall decking

•                        Test all components

 

Consultant services would include remote site inspection conducted with help from staff (e.g., pictures and video), a new set of plans and specifications, and preparation of a class 2 Opinion of Probable Construction Cost.  An issue at the facility to be addressed is how to reduce daytime temperatures in the quarantine tanks, which can rise into a range that is stressful or lethal to young steelhead.  To determine appropriate equipment for an upgrade of refrigeration facilities, an analysis of the existing power supply and loads at the facility would be performed.

 

Staff requested proposals from three local firms – Whitson Engineering, the Wallace Group, and Harris and Associates – and from Tetra Tech, the firm that provided design and construction expertise for the recently completed upgrade to the water supply.  Whitson Engineering declined to propose citing a lack of expertise for the requested services.  The Wallace Group declined to propose and stated that they would not be able to meet the schedule for the work.  Tetra Tech and Harris and Associates both provided proposals (see Exhibits 2-A and 2-B).  Both firms provided a comprehensive understanding of the services required; however, the Tetra Tech proposal was about $34,000 less than the Harris & Associates proposal for approximately the same scope of service (when excluding biddability review, bid phase support, and optional items from Harris & Associates proposal).

 

Much of the facility infrastructure is underground, is somewhat complex, and the proposed upgrades do not have comprehensive as-built information.  Staff recommends a 10% contingency be approved for this work to cover unexpected conditions at the site and to allow additional engineering services during the bidding phase for construction.

 

Because of a potentially long lead time to procure replacement tanks, MPWMD staff intend to prepare plans and specifications as a separate project and invitation for bids.  Approval for purchase of the tanks would come before the Board of Directors for consideration at a future meeting, possibly early in the fall of 2021.  Similarly, should it be warranted due to a long lead time, staff may seek approval for purchase of new refrigeration unit(s) under a separate bid in advance of construction  and will seek approval for construction of the project.   These items would also come before the Board of Directors for consideration at future meetings.

 

IMPACTS ON STAFF AND RESOURCES:  Funds for this work are budgeted under Sleepy Hollow Operations Budget Program line item 2-3-1-O Design/Construct Rearing Channel and Quarantine Tank Improvements.  The work would be performed under the direction of the District Engineer. 

 

EXHIBITS

2-A      Tetra Tech proposal dated July 12, 2021 “Rearing Channel and Quarantine Tank Maintenance Upgrades”

 

2-B      Harris & Associates proposal dated July 30, 2021 “PROPOSAL TO PROVIDE ENGINEERING SERVICES TO SUPPORT THE MAINTENANCE OF EXISTING FACILITY INFRASTRUCTURE AT THE SLEEPY HOLLOW STEELHEAD REARING FACILITY”

 

 

 

 

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[1] Hypalon is a chlorosulfonated polyethylene (CSPE or CSE) synthetic rubber (CSM) noted for its resistance to chemicals, temperature extremes, and ultraviolet light. It was a product of DuPont Performance Elastomers containing trace amounts of carbon tetrachloride (< 0.2%), chloroform (< 0.02%), and talc (< 2%).  It was popular as a material for rubber boats and was used by the US Navy.  Production was discontinued in 2009.  Internet citations show that burning Hypalon can release highly toxic fumes that are considered environmental pollutants. Additionally, some forms of Hypalon contain additives made from lead or lead compounds known for their danger.  However, the 2007 DuPont company Material Safety Data Sheet (MSDS) recommends landfill or incineration for waste disposal (the material is insoluble in water). A contractor for the District (Scardina Builders) recently removed a portion of the rearing channel liner and disposed of it at the Marina landfill.