United Kingdom · guide · 30 September 2026
Reading bund, drainage and containment findings on a CAR
Oil, chemical and leachate stores on permitted sites often require bunds, interceptors and sealed drains so polluting liquids stay on site. When Environment Agency officers record containment failures on a Compliance Assessment Report, the wording may cite cracked bund walls, unbunded pipework, blocked isolation valves, or clean and dirty water mixing. This guide helps you read those rows as printed — separate from waste acceptance or emissions findings.
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Where containment findings sit on the CAR
- Pollution prevention / secondary containment
- Site drainage / interceptors — overlap with sealed surface and drainage findings
- Leachate management — tank farms — leachate management findings
- Pollution incident preparedness — pollution incident response findings
Link each row to permit conditions — linking CAR findings to permit conditions.
Common breach descriptions
| CAR wording pattern | Plain-English reading |
|---|---|
| Bund cracked / leaking | Secondary containment integrity failure |
| Inadequate bund capacity | Volume below cited 110% or site-specific rule |
| Pipework / valve not within bund | Penetration or transfer risk |
| Bund contains debris / water | Net capacity reduced; maintenance breach |
| Surface water enters bunded area | Clean/dirty routing failure |
| Interceptor not maintained | Drainage treatment line failure |
Bunds vs sealed surfaces vs leachate
Bund rows target vessels and IBC stores. Sealed surface rows target wider yards and channels. Leachate rows target collection from waste masses. A landfill or treatment site CAR may include all three in one visit — read non-compliance text and cited conditions per row, not one blended “drainage problem”.
Scoring and foreseeable impact
Containment breaches often score as foreseeable pollution risk unless receptors were harmed. Read printed C1–C4 categories — C2, C3, CCS scores. Escalation context: what happens after a CAR, can scores increase fees.
Response actions and evidence
Actions may require immediate emptying of bunds, testing, or engineering assessment by a deadline — CAR response deadlines. Evidence to retain overlaps with what evidence to keep — photos, inspection logs, and repair invoices as your advisers recommend; CARBrief lists what the CAR itself asks for.
Reading checklist
- Identify each bund/drainage non-compliance row and cited condition.
- Note whether the CAR references a site plan or pollution prevention plan.
- Separate interceptor maintenance from bund integrity failures.
- Track points and actions per row — how to read a CAR.
Monitoring data and emissions cross-reads
Containment failures may sit on the same visit as monitoring non-compliances — monitoring data findings, emissions monitoring findings. Drainage misrouting can affect sampling points; read action lists per row rather than assuming one fix closes all monitoring gaps.
Standard rules vs bespoke permits
Secondary containment expectations differ between standard rules and bespoke permits. A CAR row citing a standard rules condition number should be read against that rule set on the Public Register — find permit online.
Pollution incident history
Where bund failures followed an incident, separate incident response rows from infrastructure maintenance rows — pollution incident response findings. Actions may sequence emergency works before permanent bund repair.
Double-skinned tanks and proprietary containment systems may be referenced by brand in officer notes; the CAR row still cites permit conditions — match generic wording to your asset register.
Rainwater entering bunds is a recurring theme on inspection summaries; actions may require lids, covers or increased emptying frequency rather than immediate engineering replacement — read deadlines separately per row.
Site warning and escalation context
Serious containment breaches may correlate with site warning letters or escalating compliance bands — site warning explained. CARBrief organises published text; it does not predict enforcement escalation.
Questions
What counts as a bund breach on a CAR?
Cracks, inadequate freeboard, valves not bunded, overfilled IBC stores, or bunds not capable of containing 110% of largest vessel when the CAR cites relevant permit or pollution prevention conditions.
How are bund findings different from sealed surface rows?
Bund rows focus on secondary containment around tanks and drums. Sealed surface rows focus on wider hardstanding and site drainage routing — both may appear on the same CAR.
Will CARBrief specify bund repairs?
No. CARBrief reads published CAR wording. Engineering specification is outside our product.
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