6.6 System Mapping, Records & Information Management
Key Takeaways
- An accurate distribution map showing mains, sizes, materials, valves, hydrants, and services is the single most valuable operational record a utility owns during an emergency.
- Valve and hydrant records should carry location, size, type, direction of operation, turns to close, date last exercised, and condition.
- As-built drawings must be updated after every main extension, repair, and abandonment, otherwise the map degrades into a liability.
- Service line material must be recorded for both the utility-owned and customer-owned portions to satisfy the Lead and Copper Rule Revisions service line inventory.
- North Carolina requires operational records documenting compliance with 15A NCAC 18C Section .1300 to be kept on the premises for three years, with longer federal retention for bacteriological, chemical, and lead and copper data.
6.6 System Mapping, Records & Information Management
The Distribution needs-to-know outline devotes a full topic area to Information Management and System Mapping, for a simple reason: at 2 a.m. during a main break, the map is the difference between isolating one block and shutting down half the town.
1. What belongs on the map
| Layer | Attributes to carry |
|---|---|
| Mains | Size, material, class, install year, joint type, lining |
| Valves | Size, type, direction of operation, turns to close, last exercised date, condition |
| Hydrants | Size and number of nozzles, auxiliary valve location, flow class color, last inspected/flowed |
| Services | Tap size and location, material of utility-owned and customer-owned portions, meter size and serial number |
| Storage and pumping | Overflow elevation, capacity, pump curves, control setpoints |
| Pressure zones | Zone boundaries, PRV and booster station locations and setpoints |
| Sampling | Routine and repeat bacteriological sites, residual monitoring sites, DBP compliance sites |
A valve and hydrant card (paper or GIS attribute record) that records turns-to-close is quietly one of the most useful tools in the field: if a valve that always took 32 turns now stops at 18, something is broken or obstructed in the valve.
2. Keeping records accurate
- Field mark before, sketch after. Every main extension, repair, cut-in, and abandonment produces a red-lined sketch with measured ties to at least two permanent features.
- Close the loop. The red-line becomes an updated as-built and an updated GIS record. A utility that draws red-lines and never files them has a map that is worse than no map, because crews trust it.
- Record abandonments. An abandoned main left on the map wastes hours during an emergency; an abandoned main missing from the map produces a surprise during excavation.
- Tie records to work orders. Repairs, leak repairs, valve exercising, hydrant inspections, and meter changes should all be recorded against the asset, which then produces a maintenance history.
3. Service line inventory
The Lead and Copper Rule Revisions require every public water system to develop and maintain a service line inventory categorizing each service line — both the utility-owned and the customer-owned portion — as lead, galvanized requiring replacement, non-lead, or lead status unknown, and to make the inventory publicly accessible. Under the LCRI, systems must replace lead and galvanized-requiring-replacement lines, generally within 10 years of the November 1, 2027 compliance date.
Practical inventory methods include historical records and tap cards, visual inspection at the meter box, mechanical scratch-and-magnet testing, vacuum excavation potholing, and predictive modeling validated by field verification. Every service the crew touches for any reason is an opportunity to confirm and record the material on both sides of the meter.
4. Records the rules require
| Record | Retention | Source |
|---|---|---|
| Records documenting compliance with 18C Section .1300 | 3 years on the premises | 18C .1302(b)(3) |
| Bacteriological analyses | 5 years | 40 CFR 141.33 |
| Chemical analyses | 10 years | 40 CFR 141.33 |
| Lead and copper monitoring and inventory records | 12 years | 40 CFR 141.91 |
| Cross-connection field test results and air gap inspections | 4 years | 18C .0406(b)(6)(F) |
| Well disinfection records (C654) | 3 years | 18C .1002(c) |
| Press release and distribution list for an untreated wastewater discharge | 1 year | G.S. 143-215.1C(b)(1) |
The ORC's own reporting. Under 18D .0701(d) the ORC reports, with each annual certification renewal, the names and PWSID numbers of every system for which they serve as ORC — and under .0701(e) must notify the Board in writing within 10 days of taking on or relinquishing a system.
5. Turning records into asset management
A basic asset management program answers five questions: What do we own? Where is it? What condition is it in? What is its remaining life? What will it cost to replace? Built from the same records:
- Break history by main identifies the pipe segments to replace first — usually a small fraction of the system generating most of the breaks.
- Valve exercising results identify the valves to replace before the next emergency.
- Meter change-out history quantifies apparent loss recovery.
- Age and material inventory feeds the capital plan and the rate study.
[!NOTE] Security caution. Detailed system maps are sensitive. Keep field copies controlled, restrict public-facing GIS to what is genuinely public, and treat hydraulic models, SCADA screens, and critical asset locations as protected information under the utility's security plan.
A valve that has historically taken 32 turns to close now stops turning at 18 turns. What should the operator conclude?
Under the Lead and Copper Rule Revisions service line inventory, how must each service line be categorized?
Which practice most directly protects a utility during an after-hours main break?