The siteId on a CustomReport determines which site's wells, sampling events, and analytical results are available when configuring content blocks in the report layout. Setting siteId correctly at creation ensures you are only drawing data from the intended site. A single Piper account may manage dozens of sites, and a custom report for one site should never inadvertently display data from another. If you want a similar report for a different site, create a new CustomReport with that site's siteId.
Technical section
Data model, API, and internals — visible to developers.