How often should an interceptor be cleaned (5 figures)

Every row is a verbatim sentence read from the named source's own page through our fetch service on the date shown, hash-pinned to the stored read (the sha of the page's visible text; the raw page is mirrored to R2).

5 of the 15 named sources that could be read published a usable figure; 10 published none and are recorded as not published, never filled in; 0 could not be read (blocked, dead or unreachable) and count nowhere.

The headline figures (median, minimum, maximum, quartiles) are over ONE figure per source for each breakdown it prices, in GBP (a source's median where its page yielded several accepted sentences for one breakdown), so a page that gives figures for several breakdowns gives one for each and N counts 5 figures, never sentences; 21 candidate sentence(s) were refused by a reviewer with the reason recorded.

The fuller derivation this dataset is chartered to grow into (not yet what the figures above are; they are each source's own published figure as read): one row per jurisdiction per obligation - service interval, the standard it comes from (BS EN 858-2 via GPP 3), who may remove the waste, the consignment-note duty and its retention period, the oil storage regime and the penalty - each quoted verbatim from that regulator's own page or the statute with its effective date.

The comparison across the four nations is the figure nobody publishes in one place, and changed-since is the news: PPG 3 was withdrawn and replaced by GPP 3, and paper consignment notes are being replaced by digital waste tracking from October 2026.

21 candidate sentences on these pages were refused by a reviewer; each refusal and its reason is recorded in the review ledger.