Weirlog is compliance field-ops for water and wastewater operators — a field ledger your permit can stand on, built to prevent the bad month, not document it afterward. Readings at the lagoon become a computed report at the desk, and a person, never the software, signs.
Position against the limit — never a grade. Illustrative values.
“Dissolved Oxygen is 93% of its 6.0 mg/L daily-min limit and has fallen across the last 4 readings (9 days). At the current rate it reaches the limit value in about 5 days.”
An actual Weirlog observation. No model, no guesswork — a straight line through your own readings, shown with its work.
Every reading is appended, never overwritten — corrections supersede with a reason, and both rows stay forever. Field entry works offline at the lagoon and syncs when signal returns, so the record is what actually happened, in the order it happened.
Limits, seasons, monitoring locations, non-detect rules, and averaging windows load from the permit itself. The DMR computes from the ledger against that configuration — and every value carries the policy it was computed under, so it can be explained a year later.
When a reading crosses a watch level you set, Weirlog attaches your own procedure — an exact-match lookup, never generated — and a named person reviews and releases it. Hold-time clocks, operator certifications, and visit records follow the same rule: computed, attributed, honest.
The numbers a tech types at the plant land in Indiana's own Monthly Report of Operation — the exact workbook your plant already files, on the state's current blank (State Form 53463, 53343, or 53344: activated sludge, lagoon, or package plant). Filled from the ledger into the form's own cells, ready to review and sign at the desk. Nobody re-keys the month.
The same readings become the discharge monitoring report, computed against the permit's limits, seasons, and non-detect rules, each value shown in position against its limit. One entry at the lagoon; the month's paperwork assembles at the desk — and a person reviews and signs both.
When a number is still legal but moving the wrong way — trending toward a per-sample limit, on pace to reach it within the month — Weirlog raises an observation with the arithmetic in plain sight: how close, how fast, and roughly when. Not AI. A least-squares line through your own ledger, deterministic and shown with its work, while there is still time to act. Your own procedures can attach to it automatically.
We loaded twenty per-tap results from a published Indiana lead-and-copper compliance round — public record — and Weirlog computed the 90th percentile at 0.0041 mg/L: the state's own published figure, exactly, including the rank rule and the multi-year monitoring period. Every computed value on every report carries a “How this was computed” disclosure — the rule, the window, the timezone, the non-detect treatment.
Weirlog computes, produces, and stages — it never files, never signs, and never holds your state credentials. Submission happens in NetDMR, by a certified human, under their own login. The software also never renders a verdict: it shows every number's position against your permit and leaves the compliance judgment where it belongs — with your certified operator.
Weirlog is built for the firm that runs other people's systems — municipal lagoons, utility districts, campgrounds, industrial parks. Multi-client from the first screen: each client's sites, systems, permits, and records stay under one roof, and a new client is a form fill, not a software project. Wastewater and drinking water both — and a public water system gets a monitoring summary, never a “DMR”, because a distribution system discharges nothing and the software should know that. Firms with their own bench give the lab tech a seat of their own; locations that buy preventative maintenance turn that section on, and the ones that don't never see it.
For Indiana operators, the timing is deliberate: since January 2026 every Indiana water and wastewater utility, IURC-jurisdictional or not, must keep an asset-management plan and report on it to the IURC every four years (HEA 1459), and the operators who keep defensible, continuous records will be the ones their clients lean on. Weirlog is built against 327 IAC and 40 CFR Part 136 record-keeping discipline from the first table.
Weirlog is in pilot with a central-Indiana contract operator through September and opens to more Indiana operator firms in October, one firm at a time. If you run systems under NPDES permits and want your field records, DMRs, and procedures in one defensible place, request an invite: we'll set your first system up with you — permit, parameters, and watch levels — and walk your first month end to end.
Request an invitePrefer email? nick@weirlog.com