ESCO ESCO Water Conservation and Efficiency 2 — Questions and Answers
Question 1: Which US federal program sets WaterSense labeled product standards that ESCOs reference when specifying plumbing fixtures?
- EPA WaterSense (Correct answer)
- DOE Energy Star for Water
- ACEEE Blue Label
- IAPMO Green Plumbing
Correct answer: EPA WaterSense
EPA WaterSense certifies products that are at least 20% more water-efficient than standard fixtures, giving ESCOs a recognized specification benchmark.
Question 2: A school district ESCO project installs sub-meters on irrigation zones. What irrigation control upgrade most directly reduces water waste?
- Weather-based (ET) smart controllers that adjust schedules based on evapotranspiration data (Correct answer)
- Time-clock controllers with manual seasonal adjustments
- Drip emitters only, with no controller change
- Pressure regulators at each head
Correct answer: Weather-based (ET) smart controllers that adjust schedules based on evapotranspiration data
ET-based controllers automatically reduce irrigation when rainfall or low temperatures reduce plant water demand, preventing over-watering.
Question 3: In a performance contract, who typically bears the financial risk if measured water savings fall below the guaranteed level?
- The ESCO bears the shortfall risk and must compensate the customer for the difference (Correct answer)
- The customer absorbs any shortfall as an operating variance
- The utility company reimburses the customer through rebates
- The equipment manufacturer covers the gap via warranty
Correct answer: The ESCO bears the shortfall risk and must compensate the customer for the difference
A hallmark of ESCO performance contracts is that the ESCO guarantees the savings and is financially responsible if actual savings fall short.
Question 4: What is 'blowdown' in the context of a cooling tower water management program?
- The intentional discharge of concentrated water to control dissolved solids levels in the tower basin (Correct answer)
- The forced-air purge of the tower fill at shutdown
- The pressure relief from high-pressure condenser water lines
- The draining of cooling coils before winter
Correct answer: The intentional discharge of concentrated water to control dissolved solids levels in the tower basin
Blowdown removes water with high concentrations of dissolved minerals to prevent scale and corrosion, and reducing unnecessary blowdown conserves water.
Question 5: Which standard published by ASHRAE provides guidance on water use benchmarking in commercial buildings?
- ASHRAE Standard 191P (Standard for the Efficient Use of Water in Building, Site, and Mechanical Systems) (Correct answer)
- ASHRAE Standard 90.1
- ASHRAE Guideline 14
- ASHRAE Standard 62.1
Correct answer: ASHRAE Standard 191P (Standard for the Efficient Use of Water in Building, Site, and Mechanical Systems)
ASHRAE 191P specifically addresses water efficiency in buildings and provides the framework ESCOs use when benchmarking and designing water measures.
Question 6: A municipality's ESCO project targets non-revenue water (NRW) reduction. Which measure most directly reduces NRW in a distribution system?
- Pressure management zones (PRZs) that lower system pressure to reduce leak flow rates (Correct answer)
- Installing advanced metering infrastructure (AMI) for billing accuracy
- Replacing iron mains with PVC only in new developments
- Increasing storage tank capacity
Correct answer: Pressure management zones (PRZs) that lower system pressure to reduce leak flow rates
Reducing system pressure in PRZs directly lowers the flow rate through existing leaks, cutting physical water losses without full pipe replacement.
ESCO ESCO Water Conservation and Efficiency 2
Which US federal program sets WaterSense labeled product standards that ESCOs reference when specifying plumbing fixtures?