Graphic organizer Grade 12 Engineering & Design
Bellowmere Creek Source Water Barriers: A Pathway Organizer
A grade 12 organizer tracing six land uses in a fictional watershed from pollutant to pathway to the barrier that interrupts it, plus a monitoring point.
Objectives
- Students will trace a pollutant from a land use through a pathway to a drinking water intake.
- Students will name the barrier that interrupts each pathway and who controls it.
- Students will identify which pollutants a conventional treatment plant does not remove.
Vocabulary
- Watershed
- A watershed is all the land where rain that falls will drain to the same stream, river, or lake. Everyone lives in a watershed, no matter how far from the water they live.
Also: source water protection, multiple barriers, pathway, residual risk, monitoring indicator
Teacher overview
This organizer is a cause-and-effect chain rendered as a six-column table, one row per source, plus a written pathway chain for the row that matters most. It maps the watershed above the intake of the fictional town of Bellowmere, which draws from the fictional Bellowmere Creek and runs a conventional filtration plant with chlorine disinfection. The misconception this organizer is built to correct is that the treatment plant is the only barrier protecting the intake. A conventional plant is the final barrier in a series that begins in the watershed, and several of the pollutants found here pass straight through coagulation, filtration, and chlorine, which is why the barrier column has to sit upstream of the intake for those rows.
Organizer
Complete every row in the table below, which covers the six land uses in the fictional watershed and the treatment plant itself. The barrier column must name something a person or agency actually builds, enforces, or maintains.
| Land use or source | Pollutant of concern | Pathway to the intake | Barrier that interrupts the pathway | Who controls the barrier | Monitoring indicator and where it is measured |
|---|---|---|---|---|---|
| Row-crop farm on the valley floor | |||||
| Older homes on septic systems | |||||
| County road salt storage yard | |||||
| Metal plating shop in the village | |||||
| Logging road on the north slope | |||||
| Pasture with livestock stream access | |||||
| The treatment plant itself |
Write the pathway chain for the row your group ranks as the highest risk, using arrows between each step.
Source → release event → transport pathway → arrival at the intake → what the plant does with it → residual risk left over
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Completed Exemplar
The entries below use the fictional Bellowmere Creek watershed.
| Land use or source | Pollutant of concern | Pathway to the intake | Barrier that interrupts the pathway | Who controls the barrier | Monitoring indicator and where it is measured |
|---|---|---|---|---|---|
| Row-crop farm on the valley floor | Nitrate from fertilizer | Leaches below the root zone into shallow groundwater, which discharges into the creek within a mile of the intake | Vegetated buffer strip along the creek plus a nutrient management plan setting rate and timing | The landowner, with cost sharing and review by the conservation district | Nitrate in the raw water tap at the plant, and in the shallow monitoring well at the field edge |
| Older homes on septic systems | Pathogens and nitrogen from failing drain fields | Surfacing effluent runs overland to a roadside ditch that drains to the creek | Septic inspection and repair program on a fixed schedule, with connection to sewer where the density is highest | The county health department | Raw water bacteria counts at the intake, and dye-test results at flagged properties |
| County road salt storage yard | Chloride from stockpiled deicing salt | Rain on an uncovered pile carries brine into the yard's drainage swale and then to the creek | Roofed storage building with a curbed pad and a closed drain | The county public works department | Raw water conductivity logged continuously at the intake |
| Metal plating shop in the village | Metals and process chemicals from a spill or an illicit discharge | A spill reaches the storm drain in front of the shop and enters the creek within minutes | Secondary containment around tanks, a spill plan, and a storm drain plug kept on site | The shop owner, under a local pretreatment and stormwater permit | Quarterly inspection records, and a raw water metals panel run by the plant laboratory |
| Logging road on the north slope | Sediment and the turbidity it causes | Road surface erodes during storms and drains directly into a tributary above the intake | Rolling dips and cross drains that spread road runoff into the forest floor instead of the tributary | The timberland owner, under the state forest practices rules | Raw water turbidity at the intake, watched during and after storms |
| Pasture with livestock stream access | Bacteria from manure deposited in and beside the channel | Animals stand in the channel and rainfall washes streamside manure directly into flowing water | Fencing set back from the bank with an off-channel watering tank and a hardened crossing | The rancher, with district cost sharing | Bacteria samples at the tributary mouth, upstream and downstream of the pasture |
| The treatment plant itself | Everything the upstream barriers did not stop | Raw water arrives at the intake and passes through coagulation, sedimentation, filtration, and chlorine | Optimized coagulation, filter performance targets, and a maintained chlorine residual | The utility and its licensed operators | Finished water turbidity and chlorine residual, recorded continuously at the plant |
Pathway chain for the highest-ranked row, the county road salt storage yard:
Uncovered salt pile → rain falls on the pile and dissolves brine → brine flows through the yard swale into the creek during winter storms → chloride arrives at the intake as a conductivity spike → coagulation, filtration, and chlorine do not remove dissolved chloride → residual risk is a salty taste in finished water and a corrosion concern in the distribution system, so the only real barrier is roofing the pile
Differentiation
Support
Pre-fill the pollutant column for all seven rows of the fictional watershed so students start at the pathway step, which is the reasoning this organizer practices. Provide one completed row, the logging road, as a worked model before students begin.
Extension
Ask students to rank all six upstream rows by how quickly a release would reach the fictional intake, then to explain why the fastest pathway is not automatically the highest risk, using the plant's ability to remove each pollutant as part of the argument.
ELL supports
Provide a simple watershed map with the six land uses and the intake marked, so each row corresponds to a place students can point to. Offer sentence frames for the pathway column: "The pollutant moves from ___ into ___, and then reaches ___," and "The plant cannot remove ___, so the barrier must be ___."
Extensions
Suppose the fictional town of Bellowmere receives a grant large enough to build only one upstream barrier this year. Ask students to choose a row, write a two-paragraph justification that weighs how likely the release is against what the plant can already handle, and state the monitoring result that would prove the barrier worked a year later.