SUMMARY OF AND RECOMMENDATIONS FOR RESPONSE TO
DEPARTMENT OF HEALTH AND HUMAN SERVICES DOCUMENT
“GUIDANCE FOR PROTECTING BUILDING ENVIRONMENTS FROM AIRBORNE CHEMICAL, BIOLOGICAL, OR RADIOLOGICAL ATTACKS”
This NIOSH – CDC document closely mimics the U.S. Army Corps of Engineers document titled “Protecting Buildings and Their Occupants From Airborne Hazards" published in October 2001 in response to September 11, 2001 terrorist attacks. In summary, the document asks several survey questions and then makes specific recommendations in four areas. I will give a brief response to the survey questions and then comment on their recommendations.
BUILDING SURVEY QUESTIONS
1) What is the mechanical condition of the equipment?
Our equipment is generally in good repair. We do have some older equipment that needs control upgrades. In the Pacific Tower, there are several areas with low-pressure ductwork that presents leakage and pressurization problems.
2) What filtration systems are in place and their efficiencies?
All our supply air is filtered to 95% efficiencies with a few exceptions. Administrative offices are filtered to 60%. SCCA areas are HEPA filtered.
It is highly unlikely that filtration would be an answer to a Chemical, Biological, or Radiological (CBR) attack, with the possible exception of HEPA filtered areas.
3) Is all equipment appropriately connected and controlled with access doors and panels in place and sealed?
Equipment is appropriately connected and controlled. No panels or doors are missing although there is likely leakage around access doors, joints, and flex connectors on some of the older equipment.
4) Are all dampers functioning and how well do they seal when closed?
All dampers are functioning and are checked on a Preventative Maintenance program. Smoke dampers on newer equipment have gasketed dampers that seal well. Older equipment does not have gasketed dampers so they do not seal well.
5) How does the HVAC system respond to fire alarms?
The HVAC system is overridden by the fire alarm system during alarms. The fire alarm system postures the building by starting the appropriate stair and elevator pressurization fans. Building fans and fire/smoke dampers are also postured to make the zone in alarm negative to surrounding zones for proper smoke removal.
6) Are all supply and return ducts completely connected to their grills and registers?
All ducts are properly connected. We do have a few areas with ceiling plenum exhaust.
7) Are the variable air volume (VAV) boxes functioning?
We have very few VAV boxes. Most systems are constant volume. The few VAV boxes we have are functioning per design.
8) How is the HVAC system controlled and how quickly does it respond?
Approximately 60% of the building is controlled by a Metasys DDC building management system. The HVAC system responds fairly fast and can be accessed from several different areas of the building via computer workstations. The remaining systems are conventional pneumatic controls and would take lengthy manual operations to change damper positions, vortexes, etc. All the fans can be manually overridden off or on at the Fire Command Center by positioning toggle switches as part of the smoke control system.
9) How is the building zoned and does it have smoke control?
The building does have smoke control. The building is zoned for smoke control in a complex matrix involving many permutations depending on the zone in alarm. In normal operation multiple fans supply defined areas, most of which include multiple floors.
10) How does air flow through the building and what are the pressure relationships between zones? Which building entryways are positive and which are negative? Is the building connected to any other buildings by tunnels or passageways?
Building airflows are very complicated given the need to have defined pressure relationships in most areas. All patient rooms are positive with the exception of isolation rooms placed in containment mode. Dirty utilities and certain lab areas are negative to surrounding areas. In general the building is positive to surrounding areas and outdoors so entryways should always be positive. The building is attached to surrounding buildings via passageways (CC to BB and RR). How the surrounding areas are postured can have a great deal of impact on UWMC posture. Also, outside climatic conditions such as wind velocity greatly impacts building posture especially in areas with open stairwells (BB-2 stairwell and RR Tower stairwells).
11) Are utility chases and penetrations, elevator shafts, and fire stairs significant airflow pathways?
A good deal of effort has gone into sealing fire penetrations so building is in good shape in that respect. All elevator shafts and fire stairs are airflow pathways due to natural stack effects. Elevator shafts and stairwells have pressurization fans for smoke control, which may or may not be of benefit during a CBR attack.
12) Is there obvious air infiltration? Is it localized?
There is no obvious air infiltration other than open stairwells as described above. Strong winds can produce some infiltration around windows.
13) Does the system provide adequate ventilation given the building’s current occupancy and functions?
Ventilation is adequate in most areas with the exception of 4th floor NN through 8th floor NN. This area will have HVAC upgrades in the future. Most other problems are related to temperature or airflow issues due to increased equipment loads or office conversions to accommodate additional staff.
14) Where are the outdoor air louvers and are they easily observable? Are they and other mechanical equipment accessible to the public?
All louvers (sixteen air intakes) are known and identified. Some are easily observable. This will be discussed under security later. No mechanical equipment is accessible if spaces are locked with one exception to be discussed under security.
15) Do adjacent structures or landscaping allow access to the building roof?
No, roofs are not easily accessible and have locked access in stairwells.
SPECIFIC RECOMMENDATIONS
1) Things not to do.
a) We have no intention of permanently sealing air intakes.
b) We have no intent to modify building systems unless a comprehensive disaster plan indicates modification would be useful.
c) We have no intent to interfere with fire protection or life safety systems.
2) Physical Security.
a) Prevent access to outdoor air intakes
The UWMC ventilation system is composed of numerous fan systems. Components of the system include 16 air-intakes, some of which supply fresh air to multiple fans. Of the 16 air-intakes, only one is at ground level. Currently this intake has a temporary wooden extension installed on it for air quality mitigation purposes. The NIOSH document also discusses relocating, extending, and establishing security zones around air-intakes. Some of this discussion will be occur in the recommendations section below.
b) Prevent public access to mechanical areas
All mechanical areas are separated from the public in secured rooms. However, over time, contractors, outside Engineering firms and others have been provided keys to these spaces. Also, mechanical areas are often left unsecured, especially during normal work hours when the maintenance staff is continually accessing these areas.
c) Prevent public access to building roofs
All stairwells leading to roofs are secured. One exception is a door leading from 9CC to the EE roof.
d) Implement security measures, such as guards, alarms, and cameras to protect vulnerable areas
Others should deal with this aspect in the Security Department
e) Isolate lobbies, mailrooms, loading docks, and storage areas
Again, this is more of a Security Department issue, but it is believed it would be quite difficult to secure these areas. Staff training may be a better approach.
f) Secure return air grilles
The nature of our ventilation systems does not lend itself to this solution. Rather than one or even a few large return air grills, our systems has literally thousands of small grills through out the building.
g) Restrict access to building operation systems by outside personnel
This guideline includes mechanical, electrical, vertical transport, and life safety systems. The Medial Center requires contractors and vendors to submit to background checks and wear proper picture ID.
h) Restrict access to building information
This guideline is addressing prints and plans that would allow adversaries to locate air intakes and/or the above operating systems. Our print room is secure, although a very large number of building prints exist in the community at large due to numerous contractors bidding on various projects over many years. Being a State Institution may also make it difficult to keep this information out of undesirable persons’ hands.
i) General building physical security upgrades
This includes security fencing, access control, etc., not within the scope of this summary/review.
3) Ventilation and Filtration
a) Evaluate HVAC control options
Our current control systems, including smoke control, allow us many options for dealing with building posturing. The problem lies in the fact that because we have so many interrelated systems, a posturing plan to deal with all possibilities will be extremely complex. It could well be that such a plan would not be feasible in an emergency. Any disaster plan needs to address this dilemma.
b) Assess filtration
Our building currently meets or exceeds all filtration codes for a Healthcare Organization. Any higher level of filtration is unlikely to be of value and is technically not feasible due to the decreased airflows that a higher level of filtration would cause.
c) Ducted and non –ducted return air systems
The concern here is that in non-ducted return air systems (open plenum exhaust), a canister of a CBR agent could be placed above the ceiling and be transported to the building supply system. We do have a few of these systems. It is highly unlikely that anyone who did not have an intimate knowledge of the building could locate these areas. A solution involving positioning return air dampers during a terrorist alert would likely mitigate the concern. This would need to be part of a comprehensive disaster plan.
d) Low-leakage, fast-acting dampers
As noted above, newer fan systems have gasketed fire/smoke inlet dampers. Older systems are subject to leakage
e) Building air tightness
In general, the building is tight due to recent recladding and window upgrades. Environmental conditions such as wind speed and direction have an effect on tightness.
4) Maintenance, Administration and Training
a) Emergency plans, policies, and procedures
UWMC has comprehensive internal and external disaster plans, plus policies and procedures dealing with utility and life safety issues. None of these plans or procedures directly addresses an airborne CBR attack. The Disaster Committee would administer any such plan.
b) Preventive maintenance and procedures
UWMC Operations and Maintenance has an excellent Preventative Maintenance program that encompasses all components of the ventilation systems.
CONCLUSIONS AND RECOMMENDATIONS
UWMC has an excellent Bioterrorism Preparedness and Response Plan from an Infection Control perspective. However UWMC does not have a comprehensive P&P to deal with an airborne CBR attack from a building infrastructure perspective. Ventilation systems are well maintained and Operations and Maintenance personnel have a good understanding of systems. However, the complexity of inter-relationships between systems leads to some real challenges if the ventilation system is the primary defense against attack.
Following the September 11, 2001 terrorist attack, UWMC Operations and Maintenance staff met several times with Infection Control personnel to formulate a plan to admit patients during a biological attack. Specifically we looked at scenarios involving a Smallpox attack. Building pressure relationships in the context of housing exposed patients while protecting staff and the community were examined. Our examination led to the conclusion that UWMC is ill suited to admit such patients; as we cannot maintain proper building pressure relationships while providing acceptable air exchanges.
Given the above, it well could be that we spend a great deal of effort and expense in formulating a plan that in the end reaches the conclusion that in an attack, we shut down all fan systems until appropriate authorities have surveyed the building for contamination and knowledgeable personnel are on site to correctly posture the building.
Recommendations: Investigate the feasibility of permenetly raising the EA and NE/NN air-takes. Building aesthetics would need to be considered. Air-takes should be capped with a grated 45-degree angled grill so any canisters etc., would roll off the air-intake. In addition, the Unit II air-intake located on the upper Plaza level of the Café, the NW/Unit I air-intake located on the NN Courtyard, and the Nuclear Medicine air-intake also located on the NN Courtyard should be considered for an angled grated cap.
Survey and retrofit all fan intake dampers that currently are not gasketed fire/smoke type.
Change all mechanical space locks to digi-pad style. This would allow programming and de-programming for contractor access. Retrofit the door leading from 9CC to the EE roof with lock mechanisms that only allow passage during a fire event or with a key limited to certain personnel. Other security measures as deemed appropriate by Security Officer and Administration.
Convene a committee composed of Operations and Maintenance, Disaster Committee Chair, Infection Control, and Campus Engineering to discuss feasible options before a P&P is written to deal with a CBR attack. Operations and Maintenance would then write P&P providing details to comply with the recommended concept.
Resources needed and action plan to write a P&P. Operations and Maintenance needs to survey fan intakes for acceptable inlet damper types. An outside Engineering firm would then need to design and estimate cost for proper replacement.
Operations and Maintenance needs to provide details to Campus Records for them to create CAD drawings showing locations of air-intakes, including fan systems served. CAD prints showing building areas served by each fan system need updating to reflect recent construction activity.
If the building smoke control system is to be part of the P&P, an Engineering study of how to manage control of the system will be needed.
Coordination of Security, Disaster Officers, and Operations and Maintenance personnel needs addressed.
In conclusion, UWMC Operations and Maintenance has the knowledge and skills to develop a comprehensive P&P dealing with a possible airborne CBR attack. However, there are multiple solutions to this task necessitating further discussion before such a P&P is written and implemented.
7