It wouldn't hurt to complete the date of establishment, add the day.
20 km south east
Replace "south east" for SE. Later you also say "east", replace for E. Id also suggest using map coordinates, it adds a nicer and more official touch.
Remember codenames go between quotes.
hanger
Hangar.
testing, research and development
Shorten these three to "Research", it implies the testing and development aspects of it.
phenomenons
Phenomena is the right word.
lethal classes
Lethality.
Based on the threat of the anomalies
Remember they are classified by difficulty of containment and lethality rating. Threats aren't entirely used for this, but if you are doing it this way it would help to clarify it is about the hazard types not the containment ratings.
could benefit from the use of controllable anomalies.
The use of "benefit" right after "beneficiary" is kind of redundant, I would suggest you replace "benefit" for "advantage".
Most sectors of the facility, especially the residential and Research and Development department, which were built to contain and analyze Theta and low threat anomalies.
This line reads like it wasn't completed, it's never stated what is important or what was done to most sectors of the facility.
by anomalies
"of" should be used instead of "by".
compliments R&D
Complements.
authority's
Capitalize this.
biological
Biological hazards mostly refer to threats caused by biological agents such as bacteria, viruses, parasites and fungi. So, you can cover the ones mentioned before this with this term.
These are the things I could spot, aside from these, this work is impeccable.
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