Graphic organizer Grade 12 Careers & CTE
Ferncastle Boil-Water Advisory: Who Acts and Under Which Credential
A grade 12 careers crosswalk organizer mapping each step of a fictional boil-water advisory to the role, credential, record, and handoff that the step requires.
Objectives
- Students will map each step of a water quality emergency to the role that performs it.
- Students will identify the credential that authorizes each action and the record it produces.
- Students will trace the handoffs that connect field, laboratory, and public notification work.
Vocabulary
- Boil water advisory
- A public notice telling people to boil tap water before drinking it because germs may have entered the pipes, often after a main break or a loss of pressure.
Also: certified sampler, responsible official, free chlorine residual, total coliform, handoff
Teacher overview
This organizer is a crosswalk that maps one water quality emergency onto the jobs a utility needs in order to respond to it. Students read three short sources about a fictional utility, the Ferncastle Water Works, and then fill a row for each step of the incident with the role that acts, the credential that authorizes the action, the record it produces, and the person who receives the handoff. The common student assumption is that one operator handles an event like this from start to finish. In practice, sampling, laboratory analysis, and public notification are separate responsibilities held by separate credentialed people, and the organizer is designed to make those boundaries visible.
Organizer
Read the three sources, then complete the crosswalk. Every fact you need is in the sources.
Source 1: Incident log, fictional Ferncastle Water Works (serves about 18,000 people)
| Time | Event |
|---|---|
| Tuesday 02:10 | A supervisory control alarm reports the Kellow Street zone falling to 8 psi after a 12-inch main break. |
| Tuesday 03:40 | The break is isolated and zone pressure returns to 44 psi. |
| Tuesday 04:15 | Samples are collected at three hydrants in the affected zone. |
| Tuesday 06:00 | A boil-water advisory is issued to 640 service connections. |
| Tuesday 10:30 | First-round results report total coliform present at one of the three sites. |
| Wednesday 11:00 | Second-round results report total coliform absent at all three sites, with a free chlorine residual of 0.9 mg/L. |
| Wednesday 14:00 | The advisory is lifted and the affected customers are notified. |
Source 2: Credential rules in the fictional state that licenses Ferncastle
| Action | Who may perform it |
|---|---|
| Direct a valve or flushing sequence, or change disinfection | A licensed distribution operator |
| Collect a compliance sample | A certified sampler, who may also hold an operator license |
| Analyze a compliance sample | An analyst at a state-certified laboratory |
| Issue or lift a public advisory | The designated responsible official for the water system |
| Serve as competent person on an open excavation | A qualified excavation competent person |
| Identify which addresses fall inside an affected zone | The district mapping technician, using the distribution map of record |
Source 3: Benchmarks the staff apply
- Systems typically maintain a free chlorine residual of 0.2 to 2.0 mg/L in distribution.
- The fictional Ferncastle procedure requires a full round of samples reporting total coliform absent at every site before an advisory may be lifted.
Crosswalk to complete
| Step from the incident log | Role that acts | Credential that authorizes the action | Record produced | Handoff goes to |
|---|---|---|---|---|
| 02:10 low-pressure alarm | ||||
| 03:40 break isolated | ||||
| 04:15 samples collected | ||||
| 06:00 advisory issued to 640 connections | ||||
| 10:30 first-round results reported | ||||
| 11:00 second-round results reported | ||||
| 14:00 advisory lifted |
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Completed Exemplar
| Step from the incident log | Role that acts | Credential that authorizes the action | Record produced | Handoff goes to |
|---|---|---|---|---|
| 02:10 low-pressure alarm | Distribution operator on the night shift, with the mapping technician identifying the zone | Distribution operator license; mapping technician uses the distribution map of record | Alarm acknowledgment and shift log entry naming the zone and the 8 psi reading | Crew lead dispatched to the break, and the operations supervisor notified |
| 03:40 break isolated | Excavation crew under a crew lead, with the distribution operator directing which valves close | Excavation competent person for the open trench; distribution operator license for the valve sequence | Valve operation record and repair report noting pressure restored to 44 psi | Distribution operator, who schedules flushing and sampling |
| 04:15 samples collected | Certified sampler working the affected zone | Sampler certification, held in this fictional system by two of the distribution operators | Chain of custody form with site, time, and residual for each of the three hydrants | Courier to the state-certified laboratory |
| 06:00 advisory issued to 640 connections | Designated responsible official, using the address list from the mapping technician | Authority of the responsible official designated for the system | Public notice text, distribution list, and time of issuance | Customers, the primacy agency, and the utility's phone line staff |
| 10:30 first-round results reported | Laboratory analyst at the state-certified laboratory | Employment at a certified laboratory under its approved methods | Signed laboratory report showing total coliform present at one of three sites | Distribution operator and responsible official, who keep the advisory in place |
| 11:00 second-round results reported | Laboratory analyst at the state-certified laboratory | Employment at a certified laboratory under its approved methods | Signed report showing coliform absent at all three sites with a 0.9 mg/L residual, within the usual 0.2 to 2.0 mg/L range | Distribution operator, who confirms the system is stable, then the responsible official |
| 14:00 advisory lifted | Designated responsible official, on the distribution operator's confirmation | Authority of the responsible official; the fictional procedure requires a full round reporting coliform absent at every site | Lift notice, final incident summary, and the record of both sample rounds | Customers, the primacy agency, and the utility's records file |
Differentiation
Support
Give these students a word bank of the six roles and the six credentials from Source 2 and let them place each one rather than recall it, and pre-fill the first row of the crosswalk as a model. Reduce the task to the first four steps of the fictional incident and allow partners to divide the remaining rows.
Extension
Ask students to add two columns to the completed crosswalk: how long the step took in the fictional incident, and what would have delayed the whole response if that role had been vacant that week. Then have them write a short paragraph naming which single vacancy would have delayed the lift of the advisory the longest, using the log times as support.
ELL supports
Pre-teach advisory, sampler, chain of custody, residual, and responsible official with short definitions and icons. Provide the crosswalk with the Role column already completed so students fill only the credential, record, and handoff columns, and allow them to answer in noun phrases rather than full sentences.
Extensions
Have students find a real boil-water notice posted by any utility and mark which of the five crosswalk elements the notice makes visible to the public, which it leaves unstated, and which job title they would have to look up to identify. Comparing the public notice with the fictional Ferncastle crosswalk shows how much staffed work sits behind a short public message.