S02_RFP Attachment SOW rev 1.pdf

STATEMENT OF WORK

Construction Services: Water Usage Study, Install Main Water Well and Tower

PROJECT # 673-21-144

Completion by 550 days after notice to proceed.

Section I - SCOPE OF WORK

A. Executive Summary

The City of Tampa supplies water to the James A. Haley Veterans Medical Center through three connections from the city's water mains. These connections support a distribution loop around the campus, supplying water to fire hydrants and some smaller buildings, as well as the Central Energy Plant and a booster pump for an elevated water tank, which is inadequate for current storage needs. An existing well used intermittently as a backup supply is currently not in use due to issues.

Dedicated irrigation wells supply irrigation systems, which are not part of this project.

The proposed solution to increase system pressures and increase water storage volume is to feed the distribution system from a new larger elevated tank. The tank booster pumps will be fed directly from the City of Tampa service connections through new pipes separate from those of the campus distribution system. The booster pumps will fill the tank and the tank will supply flow and pressure by gravity to the entire distribution system, which will include the fire hydrants. The hydraulic model of the new system indicates significant increases in flows and pressures under this scenario, that will meet current requirements. A new well will provide a backup water source and a chlorination system will provide disinfection for the well water.

The existing water tank, pumps, and appurtenances will be demolished after the new system is operational, so there will be no interruption of water service to the hospital. The existing well will be abandoned.

The new water tank site will be powered from the campus’s normal distribution network with standby power fed from the campus’s essential distribution network. The water tank will tie into the campus Advanced Metering Infrastructure (AMI) at building 55 SCADA head-end equipment to allow monitoring of the tank alarms, power, and water usage.

B. Goals and Needs:

1. Improve overall Water System reliability and performance from James A. Haley.

2. Demo the aged water tower (150,000 g)

3. Build a new water tower (1,000,000 g).

4. Demo the aged well near the water tower.

5. Build a new well near the water tower.

C. Place of Performance James A. Haley Medical Center

Building #1 – Main Hospital 13000 Bruce B. Downs Blvd.

Tampa, Fl. 33612

D. Hours Of Operation and Scheduling

Standard work hours for this site are 7:30 AM to 4:00 PM Monday through Friday except for Federal Holidays. If the Contractor desires to work on Saturday, Sunday, holidays, or outside the project site’s standard working hours the Contractor must submit a written request for approval to the COR at least seven (7) working days prior to the proposed start of such work.

E. COMPLIANCE

The contractor shall comply with all the construction documents provisions and all applicable Department of Veterans Affairs Master Specifications and all project specifications herein. Also, all the permits, and regulations from the State of Florida, Hillsborough County, and City of Tampa.

Work shall include all work as discussed below.

Section II – Basis of Design Narrative

I. Civil

A. Existing Conditions:

The James A. Haley Veterans Medical Center (Medical Center) is situated in a campus-style setting bounded by 131st Street to the north and Bruce B. Downs Blvd to the east. The western and southern boundaries are multi-family residential developments. The campus is situated within a residential/commercial area of the City of Tampa.

The City of Tampa provides the water supply to the James A. Haley Veterans Medical Center.

Tampa’s drinking water is treated and disinfected to produce high- quality drinking water that meets all federal and state drinking water regulations. The Water Department primarily uses chloramine (ammonia added to chlorine) to disinfect the water. However, they switch to chlorine disinfection several times a year, usually in the winter and summer. Chlorine is a strong disinfectant that kills bacteria, helping ensure that the water remains safe to drink as it travels through the water mains and service lines. This temporary change in disinfection method lasts for three weeks at a time.

There are three water supply connection points to the VA Medical Center from the City’s water mains surrounding the site. All three connections are 8” diameter and include a meter and a backflow preventer. The service connection to the north connects to an 8” main in 131st Street, the connection to the east connects to a 12” main in Bruce B. Downs Blvd, and the connection on the west side of campus connects to an 8” main between the VA property and the adjacent residential development. Water use from each water service connection is metered and recorded by the City of Tampa.

The service connections all feed into the water distribution system looped around the campus. The fire hydrants throughout the campus are fed directly from the distribution loop, as well as the domestic water for a few of the smaller buildings on campus. The distribution loop also feeds the Central Energy Plant (CEP) and the booster pump that fills the elevated water tank. The existing booster pump at the elevated tank is a one pump system. While the pump is of adequate capacity, there is no redundancy in case of pump failure. If the pump does fail the current backup plan is to feed Building 1 directly from the lower pressure distribution loop. This will ensure water supply to Building 1, but at a somewhat reduced pressure and volume.

Most of the existing distribution piping size and layout appear to be adequately networked or looped which improves the efficiency of the hydraulic flows and pressures throughout the Campus and improves reliability. Some of the buildings are served directly from the looped 8-inch water line, while the remainder are served from the water tank via the domestic water booster pumps in Building 1. The fire hydrants around the site are connected directly to the distribution system and therefore the fire hydrants are fed directly from the City connections and not from the elevated tank, so they do not benefit from the pressure boost provided by the elevated tank.

Based on the 2021 fire hydrant flow testing the current distribution system provides a below-average range of static pressures (40 to 60 psi) with poor hydrant flow rates ranging from 375 to 787 gallons per minute at poor residual pressures ranging from 15 to 38 psi. This existing distribution system is inadequate to supply the recommended on-site water flow of at least 1500 gpm at a residual pressure of 20 psi.

Hydrant Number Flow (gpm)

Static Pressure

(psi)

Residual Pressure

(psi)

1 650 40 30 2 750 58 37 7 581 60 30 8 581 40 28 9 581 40 28

10 581 38 22 12 712 58 30 15 787 60 38 16 750 57 38 17 750 58 38

20 Main Hospital Entry 712 60 30 21 Near Emergency Entry 650 58 15

22 Beside Bldg 1 375 30 15

There is an existing well near the existing water tank that has been used intermittently for a backup water supply. The well has been experiencing issues recently and is not currently being used. The irrigation systems are supplied by dedicated irrigation wells separate from the domestic and fire water systems. Therefore, the irrigation systems are not included in this project.

B. Demolition:

Site demolition includes removing the existing elevated water tank, its enclosure area, and all associated facilities and utilities within the enclosure. In order to avoid interruption of service to the hospital, the demolition of the existing tank must wait until the new elevated tank and systems are constructed and approved for use. Existing piping, curbs, curb and gutter, sidewalk, asphalt, and concrete pavement will be removed for utility construction and tie-ins. The new elevated water tank site and the adjacent construction area will be cleared. The Contractor shall remove a 20” Oak tree will be removed for the installation of a backflow preventer and a new connection to the City water main in Bruce B. Downs Blvd.

C. Site Layout:

The new elevated water tank site has been located east of the parking garage and south of Building 54. The tank site will include the tank, booster pumps system, the new domestic water supply well, and a prefabricated packaged chlorine feed system in a fiberglass building.

An above-ground backflow preventer unit and meter will be installed near the entrance to the Medical Center on Bruce B. Downs Blvd to facilitate a new connection to the City water main. The existing tank site will be converted to a grass area after the demolition of the tank and all appurtenances, including the perimeter wall.

D. Site Utilities:

The water system will be reconfigured such that the distribution system will be fed from the elevated tank. This will provide adequate fire hydrant flows and make fire flow storage available to the entire campus. New 8” water mains will be installed along from two water service connections (City meter locations) to the elevated tank booster pumps. The discharge piping from the tank will feed the distribution system through multiple connections for redundancy.

The fire hydrant flow tests indicate that the flows and pressures in the distribution system are inadequate. We have conducted a hydraulic model of the water system, including the City water mains surrounding the site, the service connections, water meters, backflow preventers, the campus piping system, elevated tank and booster pump. The model indicates that the low pressures are not due to excessive pressure loss within the campus piping but are mostly due to the pressure losses generated as water passes through the meters and backflow preventers getting from the City system to the campus system.

Increasing pipe sizes in the distribution system would not significantly increase the pressures available at the fire hydrants.

The proposed solution to increase system pressures is to feed the distribution system from an elevated tank. This requires a fundamental change in the operation of the system. The tank booster pumps will be fed directly from the City of Tampa service connections through 8” pipes separate from those of the campus distribution system. The booster pumps would fill the tank and the tank would supply flow and pressure by gravity to the entire distribution system, which would include the fire hydrants. The hydraulic model indicates significant increases in flows and pressures at all points in the system under this scenario.

The existing elevated tank is filled by a booster pump at the base of the tank. There is only one pump, with no backup. The proposed improvements utilize a duplex booster pumping system which increases reliability, providing redundancy for this critical component of the water system. The two-pump system will alternate pumps, and controls will operate the pumps based on level in the elevated tank. The booster pumps will be located in the base of the new water tank and be provided with variable speed controls to accommodate fluctuations in the pressure of the City water system that will feed the pumps.

The existing elevated water tank does not provide adequate storage for the current criteria. The physical security criteria for the design and construction mission-critical facilities require that at a minimum, water storage shall support 4 days of operation based upon the design criteria summarized below:

a) Potable Water: 40 gallons per day per person. For the Tampa VA Medical Center that would translate to:

40 gpd/capita x 4000 capita/day = 160,000 gpd x 4 days = 640,000 gal

b) Energy Plant Water (cooling tower and boiler make-up):

The peak monthly use for 2020 was 4,819,000 gallons which translates to an average daily flow of 166,172 gallons. Total potable storage for 4 days would be 664,688 gallons.

c) Fire Protection Water: A minimum of 120,000 gallons must be supplied and when unfavorable conditions occur, the minimum fire demand shall not be less than 180,000 gallons. Unfavorable conditions do not appear to apply at the Tampa Medical Facility, therefore the minimum storage for fire protection would be 120,000 gallons.

In summary, the minimum water storage volume required by this reference document would be as follows:

Potable Water 640,000 gallons

Industrial Water 664,688 gallons

Fire Protection Water 120,000 gallons

Total Minimum Required Storage 1,424,688 gallons

The closest nominal tank size to this requirement would be a 1,500,000-gallon tank. We believe this size tank is excessive and could cause water quality issues due to longer residence times and chlorine degradation. The manual allows for a reduction of the volume requirement if backup sources are provided. Two wells are planned as backup sources: one for CEP water (to be installed as a part of a different project) and one for domestic water.

With the very reliable source of a major City such as Tampa and the inclusion of backup wells that have more than enough capacity to supply the average daily demand, we believe a significant reduction of the storage volume requirement is warranted.

A new 1,000,000-gallon elevated water tank is proposed as a part of the water system improvements. Since 1,000,000 gallons is less than the calculated requirement of 1,500,000 gallons, the Hospital has received a waiver for the size reduction, based on having backup sources of water supply. There are several feasible locations for siting the new water tank, however, the recommended location is beside the parking garage, which is the site preferred by the VA.

A prefabricated chlorine feed system contained in a fiberglass building will be included at the tank site for chlorinating the well water and for boosting chlorine residuals in the elevated tank at any time it may be needed. Chlorine sensors will be included in the system for monitoring chlorine levels.

E. Permits:

Utilities permit from the City of Tampa will be required.

F. Stormwater Management:

The impervious area of the project is decreasing with the transition of the existing tank enclosure to grass, and the total disturbed area will be less than 1 acre. Therefore, according to the Florida Department of Environmental Protection (FDEP), additional stormwater measures will not be required for this project. Per the criteria of Hillsborough County, it does not appear this project requires additional stormwater measures to satisfy their requirements.

G. Erosion and Sediment Control:

In the same manner as Section F: Stormwater Management, this project does not require approval or permitting from FDEP, although it is still required to follow general and jurisdictional best practices for E&S control. Thus, tree protection, silt fence, and inlet protection are provided per the State of Florida E&S Designer & Reviewer Manual and Hillsborough County Transportation Technical Manual 2021 Standard Drawings.

II. Electrical

A. Existing Conditions:

The existing medium voltage 13,200V system is established at building 54 just north of the proposed new water tower site. The VA receives four circuits from the utility provider TECO, two circuits terminating on 1200A

Normal Switchgear ‘N2’, and the other two terminating on 1200A Normal Switchgear ‘N1’ within building 54.

Switchgear ‘N1’ and ‘N2’ feed out to campus on six normal feeders, and two essential feeders, which are all tied together in a loop configuration. Building 54 has (7) 2 megawatt (MW) generators for standby power which tie into the switchgear listed above. The VA has a load-shed program in place in case of extended outages.

There is an existing electrical underground circuit identified within the new water tower footprint. We believe it is branch wiring for a light pole and emergency call box.

The facilities are in a hurricane zone, coastal, and High Humidity Area, special design requirements are applicable to this project, such as stainless-steel enclosures for exterior equipment and windblown debris.

B. Demolition:

Electrical demolition will include, but not be limited to, demolition, splicing, and rerouting of the existing power and telecom distribution systems related to the existing water tower and interrupting the proposed water tower location. The project will demolish wiring back to the last active source, and conduit where exposed or in the new construction zone. Conduit not accessible will be abandoned in place.

To avoid interruption of service to the hospital, each item identified for demolition must be coordinated with the COR prior to demolition.

C. Power Distribution:

The new elevated water tank site will be fed from an existing 500kVA, 13.2kV- 480Y/277V pad-mounted transformer denoted from the campus’s normal distribution network. A secondary feed will be provided from an existing 500 kVA, 13.2kV- 480Y/277V pad-mounted transformer from the campus essential distribution network to meet the requirements of standby power.

The service will be a 4-pole Service-Entrance-rated automatic transfer switch (ATS) to a distribution panelboard at 480Y/277V, 3PH, 4W, 60Hz. Surge protection devices and ground fault protection will be provided for the distribution panelboard. Each of the pumps will be fed from the distribution panel, and separate feeders will provide power to a step-down transformer for the water tower and outbuilding. The outbuilding will be a prepackaged unit with lighting, HVAC, controls, and other auxiliaries as required for a complete and usable system. The service to the outbuilding will be provided at 208Y/120V, 3PH, 4W, 60Hz.

The wiring will be copper with thermoplastic insulation. Minimum wire sizes are #12 AWG. The minimum conduit size is 3/4-inch, utilizing RMC where exposed. The conduit underground and embedded in concrete will be PVC. Branch wiring will be concealed above the ceilings or run exposed in a neat and orderly fashion in areas without ceilings. Conductors will be run within new wall construction and surface mounted to existing structures to remain. Voltage drop on feeders and branch circuits will be limited to 5% for the building distribution system, with no more than 3% allowed on branch circuits and 2% on feeder circuits.

D. Exterior lighting:

Exterior lighting will include site pole-mounted lighting. The lighting zone is recommended as LZ1 and the lighting fixture shall be dark sky compliant. Controls will include photocell control integral to the site lighting fixture.

Space Type Illuminance level (fc) Calculation Height Ratio Source Utility Yard 0.5 fc 0 N/A UFC 3-530-01

In addition, the water tower will require obstruction lighting. The water tower lights must comply with FAA lighting requirements FAA AC 70/7460-1L – Obstruction Marking and Lighting.

E. Special Systems:

Lightning protection and a grounding system will be provided for the water tank and associated equipment. A ground ring will be provided around the tank foundation.

Conduit will be provided to connect the Advanced Metering Infrastructure (AMI) and other alarm systems (fuel/water) to building 55 control room SCADA head-end equipment. This will allow monitoring of the tank alarms, power, and water usage. Meter type needs to be determined if there is a specific model the VA wants to use, or the project can state “to be compatible with the existing system.”