This dataset covers 1,620 published records filed or published between 2015 and the 2026-08-31 data cut-off, searched across water infrastructure and distribution-network terms combined with contaminant, membrane and water-quality terms. The true figure for the field as a whole depends on exactly which terms and jurisdictions are included, so this number should be read as the scope of this specific search rather than a universal count. Because publication lags filing by roughly 18 months, the most recent one to two years will keep rising as more records post.

The assignee ranking behind this dataset covers 100 companies, with the leader holding 117 records and the top five combined holding 373 records — 23.0% of all 1,620 records in scope. The field is not dominated by one player: after a clear leader, the count drops fairly quickly by fifth and tenth place, and the remaining two-thirds of records sit with a long tail of smaller filers. Several leading assignees are dedicated water-monitoring or utilities groups, though at least one is a healthcare-equipment maker whose membrane and dialysis patents overlap this search's contaminant and membrane-flux terms.

Filings peaked at 155 in 2017 and have since settled to a lower, largely flat level: 66 in 2021 and 68 in 2024, a +3% change over that span — the most recent three years that can be treated as fully published. That is a steady field rather than one in rapid growth or in decline. Figures for 2025 and 2026 are still incomplete because publication typically lags filing by around 18 months, so they should not yet be read as a downturn.

Water and wastewater treatment (IPC class C02F) covers 29.0% of the 1,620 records in scope, closely followed by material analysis and testing (G01N) at 27.3%. Water supply and distribution infrastructure (E03B) and separation processes such as filtration (B01D) cover 15.4% and 11.5% respectively, while control systems, structural testing and flow measurement classes add a substantial sensing and data layer on top. Because records often carry more than one class, these shares add up to well over 100% of the record total, reflecting how tightly monitoring and treatment claims are bundled in this field.

Relative to the dense core of treatment-process and general monitoring claims, several specific sub-areas show lower record density: mobile point-of-network sampling units, membrane-flux degradation prediction models, and real-time treatment-efficiency control loops among them. These are not guaranteed to be open — they simply carry fewer records in this search than the core classes do — so any filing strategy built around them should start with a targeted prior-art check rather than an assumption of a clear field. Cross-utility data-sharing protocols also appear thinly covered given how much of the field now runs on data infrastructure.