654-18-807 - Design Narrative - Construction Documents.pdf

Construction Documents Water Monitoring and Treatment Project Number: 654-18-807 Design Narrative

Northeast Infrastructure, LLC 1100 Church Street

Honesdale, PA 18431

(570) 253-0846

February 18, 2021

VA Sierra Nevada Healthcare System Reno Campus 975 Kirman Avenue Reno, NV 89502-0105

DEPARTMENT OF VETERANS AFFAIRS

MEDICAL CENTER

RENO, NEVADA

PROJECT NO. 654-18-807

WATER MONITORING AND TREATMENT

ENGINEERING NARRATIVE

Prepared By

Northeast Infrastructure, LLC A Service Disabled Veteran Owned Small Business

1100 Church Street Honesdale, PA 18431

FEBRUARY 18, 2021

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Water Monitoring & Treatment Project No. 654-18-807 Construction Documents VA Medical Center, Reno, NV 02-18-2021

VAMC Reno, NV 654-18-8072

DEPARTMENT OF VETERANS AFFAIRS

VA MEDICAL CENTER

RENO, NEVADA

PROJECT NO. 654-18-807

WATER MONITORING AND TREATMENT

TABLE OF CONTENTS

I. GENERAL

II. EXISTING FACILITY DOMESTIC WATER SYSTEM DESCRIPTION

III. PLUMBING LEGIONELLA MITIGATION STRATEGY

IV. PROPOSED PROJECT SCOPE OF WORK AND RECOMMENDATIONS

VA Medical Center, Reno, NV 02-18-2021

VAMC Reno, NV 654-18-8073

I. GENERAL

The Department of Veterans Affairs has retained Northeast Infrastructure (NEI) to perform modifications to the domestic water system and design water monitoring systems for compliance with the VA directive on Legionella mitigation in several buildings at the Reno VA Medical Center under project number 654-18-807. The NEI team, as part of the scope of work, surveyed and mapped the potable water system to aid in modifying the water distribution system to comply with the Legionella Directive 1061.

A majority of the NEI team design effort was the survey of Buildings 1-D, 10, and 12, document, and then develop accurate existing conditions drawings of the potable water systems. This included identifying and documenting all dead legs found during the survey phase.

After completing this portion of the project, an evaluation began on analyzing the water distribution systems in each of the buildings in this project’s scope of work. Based on this evaluation, NEI designed a continuous water monitoring system to meet the intent of the VA design guidelines.

NEI also addressed ICRA control measures based on the anticipated level of disturbance and patient risk factors. This ICRA evaluation is communicated through the contract documents while working with the hospital Infection Control department.

It is not anticipated that this project, on its own merits, will provide closure to the overall legionella mitigation plan due to budgetary constraints however it does enhance the existing facility’s domestic water system in combatting the proliferation and exposure to legionella in the water supply which is the intent of Directive VHA 1061.

Generally, the design approach for this project was based on the following objectives:

1. Survey and document the existing domestic water systems in Building 1-D, Building 10, and Building 12.

2. Provide monitoring and telemetry of real-time, building domestic water conditions related to pressure and temperature, as well as the status of critical domestic hot water generation and distribution equipment (generators, pumps, etc.). This will require connection and integration into the facility building management system

(BMS).

3. Identify, quantify, and document to the greatest extent possible, all piping which meets the definition of a “dead leg”.

4. Identify, and quantify existing piping which is not insulated and is required to be insulated (both from a Legionella mitigation and energy usage perspective).

5. Provide point of use mixing valves, to allow maintained hot water temperatures closer to the recommended 127°F distribution temperatures as per VHA 1061.

The basis of this engineering narrative and associated scope of work is limited to the proposed domestic hot and cold water plumbing systems for Building No. 1-D (Floors Basement, 1st, 2nd and 3rd), Building No. 10 (Floors Basement and 1st), and Building No. 12 (Basement through 6th Floor).

The development of this narrative is based on the culmination of survey, documentation, engineering, and design development efforts to develop the bid documents for construction.

VA Medical Center, Reno, NV 02-18-2021

VAMC Reno, NV 654-18-8074

II. EXISTING FACILITY DOMESTIC WATER SYSTEM DESCRIPTION

A. Domestic Cold Water- Building 1-D

Domestic cold water for Building 1-D enters mechanical room G1542 from the crawl space via a 3 inch supply. A 1-1/2 inch branch feeds the (2) hot water generators within the room while the 3 inch cold water supply pipe exits the mechanical room to feed other areas of Building 1-D.

B. Domestic Hot Water- Building 1-D

Domestic hot water for Building 1-D is provided by (2) steam-to-water hot water generators. The hot water generators develop hot water based on the internal controls of the generators and then distribute hot water out to the system. Two master mixing valves are installed in Building 1-D;

ensuring that the hot water supply temperature cannot create the risk of a scald injury if the internal controls on the hot water generator malfunction. The Building 1-D domestic hot water distribution is primarily horizontal on each floor with a hot water recirculation loop, consistent with the intent of Directive VHA 1061.

C. Domestic Cold Water- Building 10

Domestic cold water for Building 10 enters into Mechanical Room G16A through a 3 inch supply. Two parallel backflow preventers protect the incoming water service. A 1-1/2 inch branch feeds the (2) hot water generators within the room while a 3 inch cold water supply pipe exits the mechanical room to feed other areas of Building 10.

D. Domestic Hot Water- Building 10

Domestic hot water for Building 10 is provided by (2) steam-to-water hot water generators. The hot water generators develop hot water based on the internal controls of the generators and then distribute hot water out to the system. Two master mixing valves are installed in Building 10;

ensuring that the hot water supply temperature cannot create the risk of a scald injury if the internal controls on the hot water generator malfunction. The Building 10 domestic hot water distribution is primarily horizontal with a hot water recirculation loop, consistent with the intent of Directive VHA 1061.

E. Domestic Cold Water- Building 12

Domestic cold water for Building 12 enters into the crawlspace mechanical room through a 4 inch supply. A 4 inch branch feeds the (2) hot water generators within the room while a 4 inch cold water supply riser exits the mechanical room to feed other areas of Building 12.

F. Domestic Hot Water- Building 12

Domestic hot water for Building 12 is provided by (2) steam-to-water hot water generators. The hot water generators develop hot water based on the internal controls of the generators and then distribute hot water out to the system. Two master mixing valves are installed in Building 12;

ensuring that the hot water supply temperature cannot create the risk of a scald injury if the internal controls on the hot water generator malfunction. The Building 12 domestic hot water distribution is primarily horizontal on each floor with a hot water recirculation loop, consistent with the intent of Directive VHA 1061.

VA Medical Center, Reno, NV 02-18-2021

VAMC Reno, NV 654-18-8075

III. PLUMBING LEGIONELLA MITIGATION STRATEGY

A. Legionella Pneumophila/Legionnaire’s Disease

Legionella, as it is used in the context of this narrative, refers to the Legionella pneumophila or Legionnaire’s Disease. Both terms refer to a potentially fatal bacterial infection of the lower respiratory tract. Exposure to the bacteria, is generally though inhalation and/or aspiration.

Sources include any warm water system or device (man-made or natural) that disseminates water as aerosols, sprays, or mists with conditions that provide favorable conditions for growth and amplification of the bacteria. Typical healthcare sources where Legionella may be found include humidifiers, showerheads, faucets, water fountains, whirlpool baths, and respiratory therapy equipment.

The greatest risk group include the elderly (although other age groups have been identified) with individuals over 50 with suppressed or compromised immune or compromised respiratory systems or with risk factors that include heavy smokers, alcoholics, HIV patients, cancer, bone marrow, organ transplant patients and others with lung and respiratory disease.

Criteria conducive to growth and amplification of Legionella in water systems:

• Stagnant water conditions and/or plumbing system design configurations such as side-arm or dead-leg piping

• Warm water temperatures between 20 and 50°C (68° to 122°F)

• Optimal growth is at temperatures between 35 and 45°C (95° to 113°F)

• Bulk water pH in the range of 5.0 to 8.5

• Sediment, scale, deposits, biofilm within the pipe

• Microbiota including algae and many other bacteria that supply essential nutrients for growth

B. Continuous Water Supply Monitoring System

Based on the water quality analysis, the facility will be provided with a water supply quality monitoring/disinfection system generally consisting of a skid mounted package complete with water quality sensors, controls, chemicals, and feed pumps to monitor free or total residual oxidant levels and feed oxidant (biocide) to maintain the target levels desired in the system.

Monitoring of the oxidant levels will be instrumental in Legionella mitigation measures being implemented for the facility. In addition, temperature, pH, and water flow will be monitored/tracked and reported to the existing facility building management/building automation system (BMS/BAS).

C. Thermal Eradication

Thermal eradication is one of several methods used to disinfect the potable water supply at the point of use. The Heat-and-Flush (shock) method is a thermal eradication process and involves raising the hot water supply/tank temperature to greater than 140°F (60°C), preferably to greater than 150°F (66°C), then circulating and flushing through all outlets for up to 30-minutes. The flush time is a function of the temperature of the water at the outlet.

VA Medical Center, Reno, NV 02-18-2021

VAMC Reno, NV 654-18-8076

Thermal eradication produces temporary results, is labor intensive, presents a safety risk due to scalding potential, has limited effectiveness, and at best, proves effective only in the short-term (weeks to months) timeframe.

The design concept for this project is based on maintaining a constant temperature of 130°F water to all patient-care portions of Building 1-D, Building 10, and Building 12 that already have point of use mixing valves providing anti-scald protection by reducing the outlet temperature to 110°F at the faucet/shower head.

Legionella and Water Temperature

D. Chlorine Dioxide

The project has been designed to accommodate the future addition of chlorine dioxide treatment on the cold water supplies to the hot water generators. Chlorine dioxide is listed in the VA Plumbing Design Manual, and VHA 1061 as a means of eradicating Legionella in the cold water supply to the heaters and has been used in numerous applications though the VA Hospital system.

Chlorine dioxide is a highly reactive gas that dissolves in water, remains as a true gas in solution, and retains biocidal activity over a broad Ph range. Chlorine dioxide is less aggressive to copper and steel than chlorine and has been shown to be effective on the control of Legionella and pipe biofilms.

E. Cold Water Recirculation

Future domestic water projects could consider cold water recirculation as a means of reducing the potential of Legionella by keeping the domestic cold water below 20°C (68°F). In instances where water usage/circulation may be minimal or stagnant, or where cold water pipes are located near heat sources (steam pipes, heat producing equipment, etc.) the methodology of cold water recirculation may prove beneficial. Generally, a recirculation pipe, similar to a hot water

VA Medical Center, Reno, NV 02-18-2021

VAMC Reno, NV 654-18-8077 recirculation pipe, is extended from a distal point in the cold water distribution system while an electric circulator constantly circulates water in the system to prevent stagnation and to keep the temperature cold.

IV. PROPOSED PROJECT SCOPE OF WORK AND RECOMMENDATIONS

A. Building 1-D List of Corrective Action:

• Prepare and implement ICRA measures and containment in work area.

• Remove dead legs as required.

• Provide water quality monitoring panel and associated sensors for floor domestic CW, HW, and HWR and pumps. Interface into building management system.

• Insulate piping identified as “uninsulated” during the survey. Insulate the piping to meet the current VA Plumbing Design Guideline requirements.

• Provide hose-end atmospheric vacuum breaker on all outside spigots/hose bibbs.

• Provide hose-end atmospheric vacuum breaker on all service sink faucets.

• Any sink, lavatory or any other fixture served by the hot water system, and there is a potential for contact is required by Code and VHA 1061 to have mixing valves.

B. Building 10 List of Corrective Action:

• Prepare and implement ICRA measures and containment in work area.

• Remove dead legs as required.

• Provide water quality monitoring panel and associated sensors for floor domestic CW, HW, and HWR and pumps. Interface into building management system.

• Insulate piping identified as “uninsulated” during the survey. Insulate the piping to meet the current VA Plumbing Design Guideline requirements.

• Provide hose-end atmospheric vacuum breaker on all outside spigots/hose bibbs.

• Provide hose-end atmospheric vacuum breaker on all service sink faucets.

• Any sink, lavatory or any other fixture served by the hot water system, and there is a potential for contact is required by Code and VHA 1061 to have mixing valves.

C. Building 12 List of Corrective Action:

• Prepare and implement ICRA measures and containment in work area.

• Remove dead legs as required.

• Provide water quality monitoring panel and associated sensors for floor domestic CW, HW, and HWR and pumps. Interface into building management system.

• Insulate piping identified as “uninsulated” during the survey. Insulate the piping to meet the current VA Plumbing Design Guideline requirements.

• Provide hose-end atmospheric vacuum breaker on all service sink faucets.

• Provide hose-end atmospheric vacuum breaker on all outside spigots/hose bibbs.

• Any sink, lavatory or any other fixture served by the hot water system, and there is a potential for contact is required by Code and VHA 1061 to have mixing valves.

VA Medical Center, Reno, NV 02-18-2021

VAMC Reno, NV 654-18-8078

D. Water Quality and Temperature Monitoring System (Buildings 1-D, 10, and 12)

NEI recommends the implementation of water quality and temperature monitoring (hot, cold, hot water return temperatures) at various locations in the system and interface into the facility BAS in accordance with the VA guidelines. The facility will be provided with a monitoring system complete with water quality sensors, controls, interconnecting wiring and tubing to monitor free or total residual oxidant levels, in addition to the system temperatures.

E. Additional Backflow Prevention

Based on the review of the existing piping configuration, it was determined that there were water supply vulnerabilities with respect to the prevention of backflow from the building into the water supply system and from connections to mechanical or other equipment. Where backflow prevention is indicated for a fire protection line, the line shall be protected with an ASSE 1015 double check backflow preventer in accordance with the VA Plumbing Design Manual. Where a higher backflow hazard is identified (protection of potable water, process water, etc.) an ASSE 1013 reduced pressure principle backflow preventer (RPZ) will be used.

Every location where a domestic water line connects to equipment or hydronic system shall be protected with a reduced pressure principle backflow preventer. In all cases where a reduced pressure principle backflow preventer is used, the relief port shall be provided with a pressure switch connected to a local A/V alarm, and also to the BAS to alert to a pressure relief event.

Where the RPZ backflow preventer is located in an area which is not normally occupied, and there is a potential for extensive damage from a catastrophic relief pressure event, the unit shall be provided with an upstream pressure-actuated solenoid valve designed to close and limit water discharge/damage. The unit shall be equal to the ZURN FCIS system.

F. Point of Use Mixing Valves

All hand wash sinks, and lavatories shall be provided with ASSE 1070 listed point of use mixing valves meeting the requirements of the VA Plumbing Design Manual and VA Plumbing Specifications Section 22 05 23. All mixing valves shall be certified lead-free in accordance with

NSF 61/NSF 372.