Project Grade 12 Engineering & Design
Booster Pump Station Design for Ridgeview Heights: A Capstone Project
A grade 12 engineering capstone where teams calculate pump head and flow capacity to serve a fictional hillside subdivision, then select equipment within a fixed budget.
Objectives
- Students will calculate the pressure deficit at the highest point of a hillside subdivision using the standard feet-to-psi conversion.
- Students will calculate the head and flow capacity a booster pump must provide and select equipment that meets both requirements.
- Students will justify a final pump selection using cost, reliability, and capacity trade-offs within a fixed budget.
Vocabulary
- Pump station
- A pump station is a building full of powerful pumps that push water through pipes or lift it uphill. Pumps give water the extra push that gravity alone cannot provide.
- Total dynamic head (TDH)
- Total dynamic head is the total amount of lift a pump has to provide to move water where it needs to go, adding up the height it must lift the water, the friction it must overcome in the pipes, and the pressure needed at the far end. Engineers calculate it to pick a pump that is powerful enough for the job.
- Hydraulic head
- Hydraulic head is the height of water pushing down on a spot, which tells you how much pressure it creates. The taller the column of water above you, the harder it pushes.
- Pressure zone
- A pressure zone is a section of a water system that a utility manages separately because it sits at a different elevation than the rest of the town. Utilities create pressure zones so that water pressure stays safe and steady for everyone, whether they live at the bottom of a hill or near the top.
Teacher overview
The fictional Ridgeview Heights subdivision sits on a hillside above the rest of its town's water distribution system, and its highest homes do not receive enough pressure from the main system alone. Over four sessions, teams calculate exactly how much additional pressure a booster pump station must provide, determine the flow capacity the station needs, and select equipment from a fixed set of options within a stated budget. The final deliverable is a written engineering proposal presented to the fictional Ridgeview Water District Board.
Project Brief
Driving question: What booster pump station will deliver at least 50 psi to Ridgeview Heights' highest home while meeting the subdivision's peak flow demand, within a $45,000 equipment and installation budget?
Scenario: The fictional Ridgeview Water District serves a hillside subdivision called Ridgeview Heights. Its highest homes sit well above the point where the main distribution system's pressure is measured. The district's board has asked an engineering class to design a booster pump station. Each team presents its recommendation at the board's next meeting.
Given data for this project (a fictional scenario built for this exercise):
- Measured pressure at the base of the hill, where the main distribution line enters the subdivision, is 58 psi.
- The subdivision's highest home sits 130 feet higher in elevation than that measurement point.
- The district wants at least 50 psi delivered at the highest home, within the standard 40-to-80 psi range most systems target.
- Ridgeview Heights has 45 homes, each with an estimated peak demand of 12 gallons per minute (gpm).
- The equipment and installation budget is $45,000, and the pump pad must fit within a 10-foot by 10-foot utility easement.
Constraints:
- The proposal must show the head, in feet, that the pump must add. Pressure in psi alone is not enough, because pump performance curves are published in feet of head.
- The proposal must show the total flow capacity, in gpm, that the station must supply at peak demand.
- The selected pump must meet or exceed both the head and flow requirements. It must also fit the budget and the pad footprint.
Pump price and capacity sheet (fictional options built for this exercise): Copy this sheet for each team, or substitute one of your own with the same mix of qualifying and failing options. Installed cost includes the pump, motor, controls, and installation labor. Reliability is the manufacturer's rating on a scale of 1 (lowest) to 5 (highest).
| Pump | Head at rated flow | Rated flow | Installed cost | Pad footprint | Reliability rating |
|---|---|---|---|---|---|
| A | 120 ft | 560 gpm | $38,500 | 7 ft by 8 ft | 4 |
| B | 125 ft | 650 gpm | $43,800 | 8 ft by 9 ft | 5 |
| C | 105 ft | 700 gpm | $34,000 | 7 ft by 7 ft | 4 |
| D | 130 ft | 500 gpm | $36,200 | 6 ft by 8 ft | 3 |
| E | 140 ft | 800 gpm | $51,500 | 9 ft by 10 ft | 5 |
| F | 118 ft | 600 gpm | $41,000 | 9 ft by 11 ft | 4 |
Final deliverable: A written engineering proposal of two to three pages, addressed to the fictional Ridgeview Water District Board. The proposal shows the pressure-deficit calculation and the required head and flow, and it compares at least two candidate pumps from the teacher-provided price and capacity sheet. It names the chosen pump with its total cost, and it closes with a short explanation of the cost, reliability, and capacity trade-offs behind that choice.
Milestones
Session 1 (60 min) — Calculate the pressure deficit and required head: One foot of elevation costs 0.433 psi of pressure. Using that standard conversion, teams find how much pressure the 130-foot rise costs the system. They subtract that loss from the 58 psi measured at the base of the hill, which gives the pressure left at the highest home with no booster running. Teams then calculate how many additional psi the pump must add to reach the 50 psi target, and convert that figure into feet of head using the standard psi-to-feet conversion. Output: a completed pressure-deficit and required-head calculation sheet.
Session 2 (60 min) — Calculate required flow and screen pump options: Teams calculate the total peak flow demand for Ridgeview Heights by multiplying the number of homes by the peak demand for one home. They then review the teacher-provided price and capacity sheet and identify every pump model that meets or exceeds both requirements, the head found in Session 1 and the flow found here. Output: a shortlist of at least two candidate pumps that meet the technical requirements, with their listed prices.
Session 3 (60 min) — Compare candidates and choose one: Teams compare their shortlisted pumps on three criteria: cost, the manufacturer's reliability rating, and any capacity margin above the minimum requirement. They confirm that the winning pump fits within the $45,000 budget and the 10-by-10-foot pad. They then draft a short written justification for the choice, naming the trade-offs they accepted. Output: a completed comparison table and a chosen pump with a written justification.
Final session (60 min) — Finalize and present the proposal: Teams finish the written proposal, which must contain all calculations, the comparison table, the final pump choice with its total cost, and the trade-off explanation. Teams then present the proposal to the class, role-playing a meeting of the Ridgeview Water District Board. Output: a completed written proposal and a short team presentation.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Rubric
Teacher reference. The 130-foot rise costs 130 x 0.433 = 56.29 psi, which leaves about 1.71 psi at the highest home with no booster running. The pump must add 50 - 1.71 = 48.29 psi, or 48.29 x 2.31 = about 111.5 feet of head, which teams should round up to 112 feet. Peak flow is 45 x 12 = 540 gpm. On the sample sheet, Pumps A and B qualify. Pump C falls short on head, Pump D on flow, Pump E on budget, and Pump F on the pad, since its 11-foot side will not fit the 10-by-10-foot easement. Pump A is $5,300 cheaper and leaves 8 feet and 20 gpm of margin, while Pump B leaves 13 feet and 110 gpm of margin with a higher reliability rating. Either choice can earn full credit if the team's justification supports it. In the Extension, five more homes raise peak flow to 600 gpm, so Pump A no longer qualifies and Pump B does.
| Criterion | Emerging | Developing | Proficient | Advanced |
|---|---|---|---|---|
| Hydraulic calculations | Head or flow requirement is missing or calculated with the wrong formula | Head and flow are calculated but contain a unit or arithmetic error | Head (in feet) and flow (in gpm) are both calculated correctly with units shown at every step | All of the Proficient criteria are met, and the team double-checks its answer using the inverse conversion (feet back to psi) to confirm it is reasonable |
| Constraint-based pump selection | Chosen pump does not meet the head or flow requirement, the budget, or the pad footprint | Chosen pump meets most but not all of the stated constraints | Chosen pump meets the head requirement, the flow requirement, the $45,000 budget, and the pad footprint | All of the Proficient criteria are met, and the team selected the pump with the best cost-to-capacity margin among the qualifying options |
| Trade-off justification and presentation | Proposal does not explain why one pump was chosen over another | Proposal names a reason for the choice but does not compare it to the alternative | Proposal clearly compares the chosen pump to at least one alternative on cost, reliability, and capacity | Proposal clearly compares alternatives and anticipates a likely question from the water district board |
Differentiation
Support (below grade level)
Provide the pressure-deficit calculation from Session 1 already worked out through the subtraction step, so teams complete only the final psi-to-feet conversion, and provide a simplified price sheet listing only three pump options instead of a longer list.
Extension (above grade level)
Ask teams to recalculate the required head and flow for a scenario in which five additional homes are added to Ridgeview Heights at the same peak demand rate, and to determine whether their originally chosen pump still meets the new flow requirement.
ELL supports
Provide a labeled elevation diagram showing the base measurement point, the 130-foot rise, and the highest home, with the pressure and head values marked directly on the diagram. Allow the written justification in Session 3 to be organized with a provided sentence frame: "We chose this pump because it provides ___ feet of head and ___ gpm, which meets our requirement of ___."
Extensions
Invite a local water utility's distribution or engineering staff to review the class's proposal and comment on how it compares to a real booster pump station design process, including how real utilities size pumps with a safety margin above the calculated minimum.