As far as the use of chaff and flares are concerned - though the military training range is used by the USAF, the FAA is still the overseeing body - and terms the range areas as Special Use Airspace (SUA).
Found the below section in a document which covers handling SUA Environmental Processing Procedures -
5. SUA ENVIRONMENTAL CONCERNS.
In addition to other environmental considerations required under NEPA, CEQ regulations, and FAAO 1050.1E, the following are items the FAA expects to be considered, if applicable, in SUA environmental documents. This list should not be considered all-inclusive:
a. Other Times by NOTAM. When specified in the proposal, this provision permits access to the SUA area 24 hours per day. The environmental document must address the potential impact for use of the SUA during the "other times by NOTAM" period.
b. Flares and Chaff. Address the potential impact of flare and/or chaff use when this activity is specified in the SUA proposal. <-------
c. "No Action Alternative." Include discussion of this alternative.
d. Coastal Zone Consistency Determination. Include if applicable.
e. Proposed Airspace Parameters. The environmental analysis in the EA or EIS for the SUA proposal must match the airspace parameters contained in the SUA proposal (i.e., boundaries, altitudes, times of use, and type and extent of activities).
f. Non-participating Aircraft. Include a discussion of the effect of the SUA proposed action on non-participating aircraft, if applicable.
g. Mitigation. As defined in CEQ regulations, mitigation includes:
1. Avoiding the impact altogether by not taking a certain action or parts of an action;
2. Minimizing impacts by limiting the degree or magnitude of the action and its implementation;
3. Rectifying the impact by repairing, rehabilitating, or restoring the affected environment;
4. Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action; and
5. Compensating for the impact by replacing or providing substitute resources or environments.
h. Cumulative Impacts. Cumulative impacts on the environment are those that result from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency (Federal and Non-Federal) or person undertakes such other actions. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time.
i. Consultation. Consultation shall be conducted in accordance with the National Historic Preservation Act, Section 106; the Endangered Species Act, Section 7; FAAO 1210.20
"American Indian and Alaska Native Tribal Consultation Policy and Procedures," and other applicable
laws, regulations, and Department of Transportation and FAA Orders.
You can find the entire document at http://www.faa.gov/airports_airtraffic/ ... rapp8.html
Safe to say, that the chaff/flares being used by anyone, have to be cleared to operate in the US airspace. Since we cannot come up with alternatives, the non-use of flares/chaff by the Sus must have been decided by the appropriate authorities.