At the salt settling chamber at West Reservoir, Niri Flint puts settling cards, filter changes and household distribution notes beside two filters share one replacement card. The detail is easy to miss in a summary, but it determines whether a posted rule describes the place people actually use.

Niri Flint is the water quality correspondent. On this vent change visit, the work begins with a dated entry and ends with a second check from someone who did not make the first one.

The settling cards, filter changes and household distribution notes lists 26 filter runs with a source and destination mark; the previous window lists 20. Tikka Reed checked both against walk-through notes from every branch paired with the posted passage map. The number is one part of a larger handoff between the office, the people who use the service and the staff expected to maintain it.

The chamber records a combined run. The distribution crew needs the filter number before sending water onward. Residents and workers have asked the clerk to keep their accounts beside the source count rather than turn them into a single average.

Afield walk checks the route from entry point to final branch. The Year first, vent change window 1 file remains open for its scheduled decision. The next card will keep the filter number with the distribution route.