DEPARTMENT OF THE ARMY
ETL 1110-3-490
CEMP-ET
U.S. ARMY CORPS OF ENGINEERS
Washington, DC 20314- 1000
Technical Letter
No. 1110-3-490
13 May 1998
Engineering and Design
DESIGN OF CHEMICAL AGENT COLLECTIVE PROTECTION SHELTERS
FOR NEW AND EXISTING FACILITIES
1. Purpose. This Engineer Technical Letter (ETL) provides information and guidance for the
design of collective protection (CP) systems for new and existing facilities. Collective protection
provides a toxic-free area (TFA) where personnel can function without individual protective
equipment such as a mask and protective garments.
2. Applicabilitv. This ETL applies to all HQUSACE elements and USACE commands having
military construction responsibility.
3. References Appendix A contains a list of referenced and related publications
4. Distribution. Approved for public release; distribution is unlimited.
5. Background. A chemical threat to personnel can come from terrorist or wartime attacks
Protection of personnel during these events can be achieved by evacuation from the affected area
or by the use of shelters. When evacuation is logistically impossible, passive shelters that use
only sealing measures will provide protection for a short period. For long durations, a preplaced
collective protection overpressure system is required.
6. Action. Pending publication of permanent guidance, the enclosed information will be used to
assist HQUSACE, major subordinate commands, district offices, and FOA in the management
and design of collective protection systems.
7. Implementation. This letter will have routine application for all future military projects as
defined in paragraph 8c, ER 1110-345- 100.
FOR THE COMMANDER:
3 Appendices
App A - References
Construction Division
App B - Collective Protection Requirements
Programs
for Existing and New Facilities
App C - Two-Stage Airlock Design and
Processing Procedures