Identify the source and the receiving system separately
A San Martin residence needs a water-and-wastewater file that identifies the actual service arrangements. A well, a utility connection, storage tanks and a septic system answer different questions. Start by asking what supplies the home, where wastewater goes, which buildings are connected and who is responsible for each component. Then compare those representations with records and appropriate current inspections.
This guide builds an evidence packet from a real Llagas Avenue proposal and current County, Valley Water and utility resources. It supplies no private test result or unseen-system diagnosis. Use the San Martin guide, Santa Clara County overview and buying process guide while assigning the material questions to the relevant reviewers.
A local Llagas file shows several system categories
The County’s project register identifies PLN22-034, APN 825-07-048, as a submitted residence-and-garage proposal on Llagas Avenue. Its January 2022 archived site sheets label an existing well and onsite wastewater. They also distinguish two tanks dedicated to a wharf hydrant from another tank labelled for domestic use and fire sprinklers.
The important distinction is functional. A storage component intended for a fire purpose should not silently become an unrestricted domestic-supply allowance. An existing-well label does not establish current production or quality, and an OWTS label does not establish an installed system’s capacity. The sheets organize questions; the current approved file and physical investigation must establish the actual arrangement.
The separate archived septic drawing was image-only in this research and was not read. No septic design detail is inferred from its presence in the attachment list. In a purchase investigation, request the actual readable system plan and the agency records needed to interpret it. An available attachment is not a reviewed or approved system merely because its filename sounds relevant.
Distinguish County clearance from a well-construction permit
County Environmental Health’s water-system guidance describes its site and drinking-water clearance roles and the separate Valley Water construction-permit route. Valley Water’s current permitting page identifies its 2026 online application process. A building or planning file should therefore be connected to the appropriate system records rather than treated as the sole approval.
For the actual well, obtain the available identifier, completion documentation and relevant permits. Ask the current agencies which records are needed for the existing use or proposed change. A prior clearance can be important without establishing present equipment condition or every later use. Keep the clearance conditions and evidence of their completion beside the document that imposed them.
Where an additional dwelling or another material activity is contemplated, state the intended reliance explicitly. A household water question, an irrigation plan and a fire-storage requirement may involve different evidence. Ask the qualified designer and reviewing agencies how those demands must be evaluated together. Do not assume an existing installation can support the new activity simply because the parcel already has a residence.
Use the well map as an inventory clue
Valley Water’s well-information guidance says its mapped locations are approximate and that the inventory can be incomplete. It points to completion-report research for more accurate well attributes. A mapped point is therefore a lead for investigation, not a surveyed location or a complete inventory of every well that may have existed.
Match the actual well and available records through the identifier, parcel history and qualified observations. If the point does not align with what is found, ask for help reconciling the difference. Do not relocate a system on a private site plan by simply tracing the public map. Likewise, the absence of a point should not become a statement that no well is present.
Ask the seller about disused equipment and historical sources as well as the source currently serving the home. Have the relevant professional and agency explain any additional investigation or documentation needed. Keep an unresolved historical-system question visible in the property file; do not label an unexamined feature abandoned, destroyed or harmless without evidence establishing that status.
Original Llagas water-and-wastewater evidence packet
| Public record clue | What it establishes | Next evidence |
|---|---|---|
| Existing well label | The archived designer identified a well source. | Actual well identity, completion record, current condition and relevant testing/clearance. |
| Separate storage labels | Plan distinguishes hydrant-dedicated tanks from domestic/sprinkler storage. | Current approved design, installed configuration and maintenance evidence. |
| OWTS and separate septic attachment | Wastewater is a distinct design topic. | Readable approved system file, actual components and qualified present assessment. |
| Submitted project status | An application-stage public record exists. | Current decisions, permits, conditions and completion records. |
Sources: archived site sheets, register and County water clearance. Separate septic image-only sheet unread; proposed storage not assumed installed.
Choose testing that answers the actual reliance
Valley Water’s domestic-well testing program describes eligibility within specified groundwater benefit zones, an untreated-water sample and a right-of-entry requirement. Shared-well sampling has its own arrangement. Confirm eligibility directly; the program is not promised for every candidate, nor is its sample a complete production or system-capacity investigation.
Ask the appropriately qualified reviewer to define the testing question, sample point and interpretation before the visit. A test of untreated source water and a test after treatment describe different conditions. Preserve the complete laboratory report, collection details and limitations so the buyer can understand exactly what was assessed rather than relying on a summary that says only “water passed.”
Quality and quantity also need separate consideration. A favorable result for the analyzed substances does not establish that the source meets the intended demand. Ask what evidence is needed for production, equipment function, storage and the proposed use. Have the professional explain the limits of the available data instead of treating one number as a guarantee of future supply.
Verify utility service without borrowing a neighboring arrangement
California American Water identifies its 2025 West San Martin acquisition and publishes a separate service-area tariff route. For a property represented as supplied by that system, obtain its actual statement and current provider confirmation. The community name does not establish that every residence receives the same service.
Ask which parts of the service the provider maintains and which equipment remains the owner’s responsibility. If a private source also exists, have the appropriate reviewers explain the actual arrangement. Do not infer that having a public-water account resolves the condition or regulatory status of every private water component on the land.
For shared supply, obtain the actual agreement and identify access, maintenance, expense allocation and administration questions for the appropriate professional. Physical proximity to a well does not establish a right to use it. A current arrangement can also depend on more than a casual description of neighbors sharing costs, so preserve the documents supporting the buyer’s expected reliance.
Investigate wastewater capacity through its own evidence
Where treatment equipment is present, ask for its purpose, service history and the evidence used to select it. Have the specialist explain what monitoring or maintenance is needed for the actual installation. An equipment label can identify a product without establishing that it addresses the source-water issue or is performing as intended. Compare the current observations with the relevant records before assigning responsibility or budgeting replacements.
Storage requires the same attention to function and access. Ask how tanks, controls and pumps are connected, which uses they serve and what records support the represented arrangement. Keep a fire-dedicated volume distinct from an assumed household reserve. A purchase file should establish the actual installed configuration rather than simply adding all tank labels on an old drawing into one available-water figure.
The County Environmental Health gateway lists septic/OWTS clearance separately from drinking-water services. Obtain the actual wastewater file, available maintenance history and an appropriate current assessment. Match them to the buildings and use under consideration. A pumping receipt, an old plan and a development clearance may each establish something useful without answering every capacity or condition question.
Locate the components and any areas identified for future system work through qualified review. Ask how the proposed occupancy or additional accommodation relates to the authorized design. Keep the agency answer with the file. A large parcel does not by itself establish that a system can expand or that every apparently open area is available for that purpose.
Finish the packet with one row per material issue: representation, source, present finding, limitation and next reviewer. That format lets the buyer distinguish a missing record from a failed test and an agency condition from a completed installation. The final decision should rest on the actual San Martin systems being acquired and the use they are expected to support.
