Alternate Storage Site | Separation from Primary Site

You meet the alternate storage site separation requirement by designating a backup/media storage location that is far enough from your primary storage site that the same event (regional outage, wildfire, floodplain failure, civil disruption) is unlikely to impact both at once, and by documenting the rationale. The control expects a defensible “same threats won’t take both” analysis, not a generic statement.

Key takeaways:

• “Sufficiently separated” is a risk-based decision you must justify with credible threat reasoning (not miles alone).
• The alternate storage site must be identified, approved, and mapped to what data/media it protects and how it’s recovered.
• Auditors look for objective evidence: location selection rationale, tested retrieval/recovery procedures, and inventory alignment.

For FedRAMP-aligned programs, “alternate storage site | separation from primary site” is a deceptively small requirement with real operational consequences. If your backups, snapshots, offline media, or archival records sit too close to the production storage they protect, you can lose both to one incident. CP-6(1) forces a practical question: if the primary storage is unavailable because of a real-world threat, will the alternate storage still be reachable and intact?

This requirement is easy to under-implement because teams treat “alternate site” as a checkbox (“we have another bucket/replica”). Separation is about correlated risk. Two storage sites in the same metro area, power grid, flood basin, or cloud region can fail together. Conversely, separation can be achieved through geographic distance, different utility dependencies, different cloud regions, or a mix of provider and physical controls, as long as you can defend why the same threats are less likely to hit both.

Use this page to operationalize CP-6(1) quickly: define what “primary storage site” means in your environment, select and approve an alternate storage site with a documented separation rationale, and retain the evidence auditors ask for.

Regulatory text

Requirement (excerpt): “Identify an alternate storage site that is sufficiently separated from the primary storage site to reduce susceptibility to the same threats.” ¹

What the operator must do

• Identify a specific alternate storage site (not a vague concept like “the cloud” or “another data center”).
• Demonstrate sufficient separation from the primary storage site using a threat-based rationale focused on shared susceptibility.
• Reduce correlated failure risk by ensuring the alternate site is unlikely to be affected by the same disruptive event(s) as the primary site. ¹

Plain-English interpretation

You need a backup/storage location that won’t go down for the same reason your main storage goes down. “Separation” means separation from shared threats, including:

• Physical hazards (wildfire zones, flood plains, hurricanes/tornado corridors, earthquakes)
• Infrastructure coupling (same power grid segment/substation, telecom carrier, water supply, transportation access constraints)
• Logical/administrative coupling (same credentials, same control plane, same blast radius from misconfiguration or ransomware)
• Provider/regional coupling (same cloud region, same availability zone group, or same shared service dependencies)

Auditors and assessors typically accept multiple ways to achieve the intent, but they reject hand-waving. Your documentation must connect the chosen alternate site to a realistic threat model and explain why the threats are less likely to affect both sites simultaneously.

Who it applies to

Entity types:

• Cloud Service Providers operating in scope for FedRAMP authorizations
• Federal agencies operating systems that must meet NIST SP 800-53 controls ¹

Operational context (where this shows up in real programs):

• Production storage for mission/business systems (object storage, block storage, file storage, database storage)
• Backup repositories (backup appliances, immutable backup stores, tape vaulting, offline media)
• Archive/records retention storage
• DR data stores used for restore operations
• Third-party managed backup and media storage arrangements (still your control to manage and evidence)

What you actually need to do (step-by-step)

1) Define “primary storage site” in scope

Create a clear mapping of:

• Primary storage locations (by data type and system boundary)
• Where backups are written (repositories, vaults, buckets, tape vendors)
• Who administers each location (roles/teams/third parties)
• Which dependencies are shared (region, network, identity plane)

Output: Storage topology diagram + inventory table tied to your system boundary.

2) Identify credible “same threats” for your environment

You don’t need a dissertation. You need a concise list of threat scenarios that plausibly disable the primary storage site, such as:

• Regional power disruption
• Major weather event affecting a metro area
• Data center access disruption
• Cloud regional outage
• Ransomware or destructive admin action affecting the storage control plane

Output: A short threat-to-impact statement for storage availability and integrity.

3) Select an alternate storage site and document why separation is sufficient

Pick an alternate site and write a separation rationale that is specific and testable. Common patterns:

• Different geographic region (cloud region-to-region replication; offsite backup to a separate region)
• Different physical facility with different hazard exposure (separate floodplain; different wildfire risk area)
• Different administrative/security domain (separate credentials, separate backup admin roles, separate KMS keys)
• Hybrid separation (cloud backups plus offline media stored with a third party)

What “sufficient” means in practice is that your reasoning reduces the likelihood of correlated loss. Distance can help, but the core is whether the primary threat scenarios would plausibly hit both.

Output: Alternate Storage Site Designation record with: location, owner, protected datasets, separation rationale, and approval.

4) Ensure the alternate storage site is operationally usable

Separation that can’t restore is wasted. Confirm:

• Backups/replicas are actually landing at the alternate site (not just configured)
• Access paths exist during a primary outage (network routing, credentials, break-glass access)
• Recovery procedures reference the alternate site (who, how, prerequisites)
• Integrity protections exist (immutability/WORM where applicable; key management; access logging)

Output: Updated backup configuration evidence + recovery runbook.

5) Validate through testing and keep the results

Run a restore/retrieval test that uses the alternate storage site as the source. Focus on proving:

• You can access the alternate site during a simulated primary-site failure condition
• You can retrieve backup media/data
• You can restore to a known-good environment and validate integrity

Output: Test plan, test results, issues list, and remediation tracking.

6) Tie third parties to the requirement (if applicable)

If a third party stores your backup media (tape vaulting, managed backup, DRaaS):

• Contractually require site separation expectations and notification of site changes
• Get evidence of storage location(s) and separation approach
• Confirm your right to retrieve and test restores

Output: Contract clauses/SOW, third-party due diligence evidence, and retrieval SLAs/operational procedures.

Required evidence and artifacts to retain

Keep artifacts in a form an assessor can review quickly:

Core documentation

• Alternate storage site designation (named site, address/region, owner, scope)
• Separation rationale linked to identified threat scenarios
• Storage and backup architecture diagram (primary vs alternate clearly marked)
• Data classification and backup inventory mapping to locations

Operational proof

• Backup job/configuration exports showing copy/replication to the alternate site
• Access control evidence (roles, MFA, break-glass, least privilege)
• Key management design for backup encryption (where applicable)
• Restore/retrieval test records and corrective actions

Governance

• Approvals (risk acceptance if separation is constrained)
• Change management records for any site/region changes affecting separation

Common exam/audit questions and hangups

Expect these lines of inquiry:

• “Show me the alternate storage site.” Name it precisely (cloud region, facility, third-party vault).
• “Why is it sufficiently separated?” Provide a written rationale tied to threats, not marketing claims.
• “Is your ‘alternate’ on the same control plane?” If the same admins, same identity, or same keys can destroy both, assessors may view separation as weak.
• “Prove data is there and recoverable.” Configuration screenshots/exports plus a restore test result.
• “What changed recently?” Region moves, DR redesigns, backup tool migrations, or third-party changes should have change records.

Frequent implementation mistakes and how to avoid them

Mistake: Treating a second copy in the same region as “separated”

Avoidance: Document region/zone selection and explicitly evaluate regional outage as a threat scenario. If you stay in-region, you need other strong separation arguments (administrative and infrastructure independence), and you may still fail the intent.

Mistake: Separation in geography, but not in administration

If the same privileged account can delete or encrypt both primary and alternate backups, correlated loss remains likely. Avoidance: Use separate backup admin roles, hardened accounts, and independent key controls for backup repositories.

Mistake: “Alternate site exists” but no one can restore from it

Avoidance: Maintain a tested runbook and a repeatable retrieval process. Keep evidence of at least one successful restore path from the alternate site.

Mistake: No inventory alignment

Teams often can’t show which systems’ backups are actually stored at the alternate site. Avoidance: Maintain a backup coverage matrix: system → data sets → backup cadence → primary repository → alternate repository.

Enforcement context and risk implications

No public enforcement cases were provided in the source catalog for this requirement, so this page focuses on auditability and operational risk rather than case law.

Risk-wise, CP-6(1) is about preventing single-event, multi-copy loss. The real failures are correlated: a regional disaster, a cloud region incident, or a destructive action that hits primary and backups together. The business impact is usually continuity failure (extended outage) plus potential data integrity loss (inability to restore to a known-good state).

Practical 30/60/90-day execution plan

First 30 days (Immediate stabilization)

• Assign an owner for storage resilience within the system boundary (ops lead with GRC oversight).
• Produce a primary vs alternate storage inventory and architecture diagram.
• Identify your top threat scenarios that could disable the primary storage site.
• Select the alternate storage site candidate(s) and draft the separation rationale.

By 60 days (Operationalization)

• Finalize the alternate site designation and approvals.
• Implement technical changes needed to ensure backups/replicas land at the alternate site.
• Tighten administrative separation (roles, credentials, keys) for backup and alternate storage access.
• Update DR/restore runbooks to reference the alternate storage site explicitly.

By 90 days (Assessor-ready evidence)

• Execute a restore/retrieval test from the alternate storage site and capture results.
• Close gaps found in testing and document corrective actions.
• Package evidence: designation record, rationale, diagrams, config exports, access control proof, test results.
• If a third party is involved, collect their location/separation attestations and retrieval process evidence.

Where Daydream fits

If you track this control in Daydream, treat it as a requirement-to-evidence workflow: map each in-scope system to its alternate storage site record, attach the separation rationale, and keep restore test evidence and change history in one place for assessments and ongoing operations.

Frequently Asked Questions

Does “sufficiently separated” require a specific distance in miles?

CP-6(1) does not specify a distance; it requires separation that reduces susceptibility to the same threats ¹. Your job is to document a defensible rationale tied to realistic threat scenarios.

If we’re fully in the cloud, is using a different availability zone enough?

Often no, because many threats assessed at audit time are regional or control-plane related. A different cloud region is typically easier to justify as “not susceptible to the same threats,” but you still must document your specific threat reasoning ¹.

Can a third party manage the alternate storage site for us?

Yes, but you still need to identify the alternate storage site, ensure adequate separation, and retain evidence. Add contract terms for retrieval, change notification, and your right to test restores.

What evidence is the fastest way to satisfy an assessor?

A named alternate site record, a one-to-two page separation rationale tied to threats, proof backups are written there, and a restore test showing you can retrieve and recover from that location.

We have immutable backups. Does immutability replace separation?

No. Immutability helps against destructive changes, but it does not address regional disasters or shared infrastructure failures that can make both primary and backup inaccessible. You need both: integrity controls and separation rationale ¹.

What if we cannot achieve strong separation due to constraints?

Document constraints, record risk acceptance through your governance process, and implement compensating controls (administrative separation, offline copies, diversified dependencies). Expect closer scrutiny because the requirement explicitly calls for reduced susceptibility to the same threats ¹.

Footnotes

1. NIST Special Publication 800-53 Revision 5