Pseudonymising Drainage and Water Search Results for Property Transactions – UK GDPR-compliant anonymisation per UK GDPR
A CON29DW drainage and water search is a standard pre-contract requirement in residential conveyancing — part of the search pack for around 1 million transactions per year in England and Wales. It confirms sewer connections and may reveal prior owner names in drainage records. anonym.legal pseudonymises those identifiers, preserving infrastructure data; unlawful disclosure risks UK GDPR fines of up to £17.5 million or 4% of annual global turnover.
When this applies
This task applies when CON29DW search results and supporting drainage correspondence are shared with a purchaser, their lender, or a development adviser who needs the infrastructure data but should not receive the personal data of named prior owners or occupiers referenced in drainage records under UK GDPR Art. 6.
How anonym.legal handles it
- Upload the CON29DW drainage and water search results and any accompanying sewer maps or correspondence.
- The engine identifies natural persons named in the search results, notices, or correspondence — typically prior owners or occupiers referenced in connection to sewer crossings or adoption agreements.
- Each individual is pseudonymised consistently; connection status, sewer locations, public adoption information, and infrastructure specifications are preserved.
- A mapping table is produced with UK/EU data residency.
- Release the pseudonymised results for due-diligence review; restore originals before lender submission.
What you provide
- CON29DW drainage and water search results
- Sewer map or record of public sewers (if provided separately)
- Any drainage correspondence naming individuals (if appended)
Limitations & cautions
- Drainage and water searches are provided by the relevant water authority or a regulated personal search company; the tool pseudonymises personal data in the results but does not verify their accuracy or currency.
- Sewer adoption agreements are complex documents governed by Water Industry Act 1991; if the adoption agreement names individual parties, those are pseudonymised separately — upload the adoption agreement as a separate document.
FAQ
Do drainage and water searches typically contain personal data?
Most CON29DW results are infrastructure-focused and contain little personal data. Where prior owner or occupier names appear in correspondence or adoption notices annexed to the search, those individuals are pseudonymised. With over 25 million titles registered at HM Land Registry under the Land Registration Act 2002, prior ownership records from the 1950s onwards frequently reference named individuals who may still be identifiable living persons.
Is a CON29DW required by mortgage lenders?
Yes, most residential mortgage lenders require a CON29DW search as part of the pre-offer due diligence for the around 1 million residential transactions completing per year (HMRC Property Transactions Statistics 2023-24). SDLT at 5 percent on £250,001 to £925,000 and 10 percent on £925,001 to £1.5 million (Finance Act 2003 Part 4) means lenders at higher loan amounts will scrutinise search packs carefully. The original, un-pseudonymised results must be provided to the lender; the pseudonymised version is for preliminary client or adviser review.
Can this be combined with the local authority search workflow?
Yes. Upload the LLC1/CON29 and CON29DW search results together in a single batch for consistent pseudonymisation across the full pre-contract search pack. Consistent pseudonymisation across all 3 pre-contract searches protects against UK GDPR fines of up to £17.5 million or 4% of annual global turnover (DPA 2018 s.157) arising from unnecessary data circulation.
Which water authorities provide CON29DW searches?
CON29DW searches are provided by the relevant licensed water and sewerage undertaker for the property's location, or by a regulated personal search company. With around 1 million residential transactions per year in England and Wales (HMRC Property Transactions Statistics 2023-24) and over 25 million titles on the HM Land Registry open register (Land Registration Act 2002), water authorities process very large volumes of search requests — each result may reference prior owners or occupiers whose personal data requires protection. The search fee varies by provider but typically ranges from £35 to £75 per property.